WorldWideScience

Sample records for thin walled tubes

  1. Nondestructive testing of welds on thin-walled tubing

    Science.gov (United States)

    Hagemaier, D. J.; Posakony, G. J.

    1969-01-01

    Special ultrasonic search unit, or transducer assembly, reliably inspects the quality of melt-through welds of fusion welded tubing couplers for hydraulic lines. This instrumentation can also be used to detect faulty braze bonds in thin-walled, small diameter joints and wall thickness of thin-walled metal tubing.

  2. Leakproof Swaged Joints in Thin-Wall Tubing

    Science.gov (United States)

    Stuckenberg, F. H.; Crockett, L. K.; Snyder, W. E.

    1986-01-01

    Tubular inserts reinforce joints, reducing incidence of leaks. In new swaging technique, tubular inserts placed inside ends of both tubes to be joined. Made from thicker-wall tubing with outside diameter that matches inside diameter of thin tubing swaged, inserts support tube ends at joint. They ensure more uniform contact between swage fitting and tubing. New swaging technique developed for Al/Ti/V-alloy hydraulic supply lines.

  3. Expander for Thin-Wall Tubing

    Science.gov (United States)

    Pessin, R.

    1983-01-01

    Tool locally expands small-diameter tubes. Tube expander locally expands and deforms tube: Compressive lateral stress induced in elastomeric sleeve by squeezing axially between two metal tool parts. Adaptable to situations in which tube must have small bulge for mechanical support or flow control.

  4. No rotating U.S. Testing of thin walled tubes

    International Nuclear Information System (INIS)

    Furlan, J.; Boulanger, G.; Mogavero, R.

    1981-07-01

    Thin walled tube ultrasonic testing is performed, with Lamb waves, using annular transducers and conical or helicoidal mirrors. The main advantage of this already known system is dispensing with rotation of tube and/or transducer. High speed control (30 cm/s and more) is then allowed. The present paper describes the parameters influencing the sensitivity has been improved by searching, theoretically and practically, the best suited Lamb wave modes, and by using transducers which are well characterized. Practical example of cladding tube U.S. testing is described

  5. Creep behaviour of thin walled composite tubes

    International Nuclear Information System (INIS)

    Thiebaud, F.; Muzic, B.; Perreux, D.; Varchon, D.; Oytana, C.; Lebras, J.

    1993-01-01

    Fiber reinforced composites are more and more employed in high performance structure for nuclear power plant, mainly as water piping tubes. The increase of the use of composites is due to the advantages that they give : high stiffness, large ultimate strength, corrosion resistance. This last advantage is sought for the pieces in contact with water, and it's one of the reason why the composite can be preferred to metal. However the mechanical behaviour of composite is actually poorly known. The high anisotropy is the main difficulty to obtain a realistic model of behaviour. This problem implies that the safety factor used in the design of structure is often too large. In this article a general overview of the mechanical behaviour of tube made in glass epoxy material is proposed. We discuss especially the creep behaviour under biaxial loadings. The form of the proposed model presently allows predicting a nonlinearity of the behaviour and provides a good correlation with the experimental data of several tests not described in this paper. It accounts for the change of the Poisson ratio during creep and cyclic tests. However the complete identification requires long time testings and consequently the model must be corrected to take into account the damage which occurs in these cases

  6. Multiaxial loading of large-diameter, thin-walled tube rock specimens

    International Nuclear Information System (INIS)

    Hecker, S.S.; Petrovic, J.J.

    1981-01-01

    A large-scale mechanical testing facility permits previously impossible thin-walled tube multiaxial loading experiments on rock materials. Constraints are removed regarding tube wall thickness in relation to rock microstructural features and tube diameter as well as test machine load capacity. Thin-walled tube studies clarify the influence of intermediate principal stress sigma 2 on rock fracture and help define a realistic rock fracture criterion for all multiaxial stressing situations. By comparing results of thin-walled and thick-walled tube fracture investigations, effects of stress gradients can be established. Finally, influence of stress path on rock fracture, an area largely ignored in current rock failure criteria, can be examined in detail using controlled loading changes as well as specimen prestrains

  7. Thin-walled large-diameter zirconium alloy tubes in CANDU reactors

    International Nuclear Information System (INIS)

    Price, E.G.; Richinson, P.J.

    1978-08-01

    The requirements of the thin-walled large-diameter Zircaloy-2 tubing used in CANDU reactors are reviewed. Strength, residual stress patterns, texture and prior deformation contribute to the stability of these tubes. The extent to which the present manufacturing route meets these requirements is discussed. (author)

  8. Standard practice for estimating the approximate residual circumferential stress in straight thin-walled tubing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 A qualitative estimate of the residual circumferential stress in thin-walled tubing may be calculated from the change in outside diameter that occurs upon splitting a length of the tubing. This practice assumes a linear stress distribution through the tube wall thickness and will not provide an estimate of local stress distributions such as surface stresses. (Very high local residual stress gradients are common at the surface of metal tubing due to cold drawing, peening, grinding, etc.) The Hatfield and Thirkell formula, as later modified by Sachs and Espey, provides a simple method for calculating the approximate circumferential stress from the change in diameter of straight, thin-walled, metal tubing. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  9. On the characteristics and application of thin wall welded titanium tubes for heat transfer

    International Nuclear Information System (INIS)

    Nishimura, Takashi; Miyamoto, Yoshiyuki

    1985-01-01

    Because of the excellent corrosion resistance, thin wall welded titanium tubes have become to be used in large number as the heat transfer tubes of condensers and seawater desalting plants using seawater in place of conventional copper alloy tubes. Especially in nuclear power plants, the all titanium condensers using thin wall welded titanium tubes and titanium tube plates were adopted in the almost all plants under construction or expected to be constructed. In this report, the various characteristics of thin wall welded titanium tubes required for using them as heat transfer tubes, such as corrosion resistance, heat transfer characteristics, fatigue strength and expanding characteristics, are outlined, and the state of use is described. At first, relatively thick seamless titanium tubes were used for chemical industry, but thereafter, due to the advance of the mass production techniques, the welded titanium tubes of less than 0.7 mm thickness and high quality have become to be supplied at low cost. In 1969, titanium tubes were used for the first time in Japan for the air cooler in the condenser of Akita Power Station, Tohoku Electric Power Co., Inc. The features of titanium are small specific gravity, small linear expansion coefficient and small Young's modulus. (Kako, I.)

  10. Status of Joining Thin Sheet and Thin Wall Tubes of 14YWT

    Energy Technology Data Exchange (ETDEWEB)

    Hoelzer, David T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Unocic, Kinga A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tang, Wei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Feng, Zhili [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-18

    Beginning this fiscal year, the FCRD research project initiated an investigation on joining thin sections of the advanced ODS 14YWT ferritic alloy. Friction stir welding (FSW) was investigated as a method to join thin plate and tubing of 14YWT since it is a solid state joining method that has been shown in past studies to be a promising method for joining plates of ODS alloys, such as 14YWT. However, this study will attempt to be the first to demonstrate if FSW can successfully join thin plates and thin wall tubing of 14YWT. In the first FSW attempt, a 1.06 cm thick plate of 14YWT (SM13 heat) was successfully rolled at 1000ºC to the target thickness of 0.1 cm with no edge cracking. This achievement is a highlight since previous attempts to roll 14YWT plates have resulted in extensive cracking. For the FSW run, a pin tool being developed by the ORNL FSW Process Development effort was used. The first FSW run successfully produced a bead-on-plate weld in the 0.1 cm thick plate. The quality of the weld zone appears very good with no evidence of large defects such as cavities. The microstructural characterization study of the bead-on-plate weld zone has been initiated to compare the results of the microstructure analysis with those obtained in the reference microstructural analysis of the 14YWT (SM13 heat) that showed ultra-fine grain size of 0.43 μm and a high number density of ~2-5 nm sizes oxygen-enriched nanoclusters.

  11. Thin-walled beam tubes for the SIS. Construction and manufacturing

    International Nuclear Information System (INIS)

    Malwitz, E.

    1985-06-01

    The vacuum system of the SIS consists essentially of torus-shaped vacuum chamber with an annulus-circumference of 216 m which is composed by several beam-tube and chamber elements. In order to reach the desired final pressure of -11 mbar (5 . 10 -9 Pa) a heating of the whole vacuum system to 300 0 C is required. The beam tubes within magnets have regularly an elliptic tube cross section. Within bending magnets the beam tubes are curved in a plane through the large ellipse axis with a bending radius of 10 m. During the development work for the beam tubes within magnets to construction variants were studied until construction maturity. Generally thin-walled beam tubes with elliptic tube cross section are fabricated similarly to spring bellows as corrugated tubes. In this report however beam tubes with elliptic tube cross section are discussed the tube walls of which are smooth and stabilized against the atmospheric pressure by hard-soldered ribs. The report reproduces mainly the most important know how respectively serves as instruction for new constructions. Such beam tubes are planned for the dipole magnets and the quadrupole group consisting of two long quadrupoles, a short quadrupole, and a sextupole. (orig./HSI) [de

  12. Collapse of thin wall tubes with small initial ovality

    International Nuclear Information System (INIS)

    Moreno, A.

    1977-01-01

    A simple model of creep collapse of tubes based on the bending theory of curved beams is developed. The model is compared with more complex models. The main result of this study is the definition of a new model of creep collapse of tubes with a minimum of limited hypothesis. (author) [es

  13. Collapse of thin wall tubes small initial ovality

    International Nuclear Information System (INIS)

    Moreno, A.

    1977-01-01

    In this work a simple model of creep collapse of tubes based on the bending theory of curved beams, is developed. The model is compared with more complex models. The main result of this work is the definition of a new model of creep collapse of tubes with a minimum of limitative hypothesis. (Author) 6 refs

  14. Characterization of Thin Walled Mo Tubing produced by FBCVD

    Energy Technology Data Exchange (ETDEWEB)

    Beaux, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-21

    The goal of this report is to delineate the results of material characterization performed on Mo tubing produced via the fluidized bed chemical vapor deposition (FBCVD) method. Scanning electron microscopy (SEM) imaging reveals that small randomly oriented grains are achieved in the Mo deposition, but do not persist throughout the entire thickness of the material. Energy dispersive spectroscopy (EDS) reveals the Mo tubes contain residual chlorine and oxygen. EDS measurements on the tube surfaces separated from glass and quartz substrates reveal substrate material adhered to this surface. X-ray diffraction (XRD) revealed the presence of carbon contaminant in the form of Mo2C and oxygen in the form of MoO2. Combustion infrared detection (CID) and inert gas fusion (IGF) performed at Luvak Inc. was used to quantify weight percentages of oxygen and carbon in the tubes produced. Hardness value of the FBCVD Mo was found to be comparable to low carbon arc cast molybdenum.

  15. Development of laser cladding system to repair wall thinning of 1-inch heat exchanger tube

    International Nuclear Information System (INIS)

    Terada, Takaya

    2013-01-01

    We developed a laser cladding system to repair the inner wall wastage of heat exchanger tubes. Our system, which is designed to repair thinning tube walls within 100 mm from the edge of a heat exchanger tube, consists of a fiber laser, a composite-type optical fiberscope, a coupling device, a laser processing head, and a wire-feeding device. All of these components were reconfigured from the technologies of FBR maintenance. The laser processing head, which has a 15-mm outer diameter, was designed to be inserted into a 1-inch heat exchanger tube. We mounted a heatproof broadband mirror for laser cladding and fiberscope observation with visible light inside the laser processing head. The wire-feeding device continuously supplied 0.4-mm wire to the laser irradiation spot with variable feeding speeds from 0.5 to 20 mm/s. We are planning to apply our proposed system to the maintenance of aging industrial plants. (author)

  16. Assessment of thin-walled cladding tube mechanical properties by segmented expanding Mandrel test

    International Nuclear Information System (INIS)

    Nilsson, Karl-Fredrik

    2015-01-01

    This paper presents the principles of the segmented expanding mandrel test for thin-walled cladding tubes, which can be used as a basic material characterisation test to determine stress-strain curves and ductility or as a test to simulate mechanical pellet-cladding interaction. The paper discusses the strengths and weaknesses of the test method and it illustrates how the test can be used to simulate hydride reorientations in zirconium claddings and quantify how hydride reorientation affects ductility. (authors)

  17. Viability of thin wall tube forming of ATF FeCrAl

    Energy Technology Data Exchange (ETDEWEB)

    Maloy, Stuart Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aydogan, Eda [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Anderoglu, Osman [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lavender, Curt [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-16

    Fabrication of thin walled tubing of FeCrAl alloys is critical to its success as a candidate enhanced accident-tolerant fuel cladding material. Alloys that are being investigated are Generation I and Generation II FeCrAl alloys produced at ORNL and an ODS FeCrAl alloy, MA-956 produced by Special Metals. Gen I and Gen II FeCrAl alloys were provided by ORNL and MA-956 was provided by LANL (initially produced by Special Metals). Three tube development efforts were undertaken. ORNL led the FeCrAl Gen I and Gen II alloy development and tube processing studies through drawing tubes at Rhenium Corporation. LANL received alloys from ORNL and led tube processing studies through drawing tubes at Century Tubing. PNNL led the development of tube processing studies on MA-956 through pilger processing working with Sandvik Corporation. A summary of the recent progress on tube development is provided in the following report and a separate ORNL report: ORNL/TM-2015/478, “Development and Quality Assessments of Commercial Heat Production of ATF FeCrAl Tubes”.

  18. Axial Crushing Behaviors of Thin-Walled Corrugated and Circular Tubes - A Comparative Study

    Science.gov (United States)

    Reyaz-Ur-Rahim, Mohd.; Bharti, P. K.; Umer, Afaque

    2017-10-01

    With the help of finite element analysis, this research paper deals with the energy absorption and collapse behavior with different corrugated section geometries of hollow tubes made of aluminum alloy 6060-T4. Literature available experimental data were used to validate the numerical models of the structures investigated. Based on the results available for symmetric crushing of circular tubes, models were developed to investigate corrugated thin-walled structures behavior. To study the collapse mechanism and energy absorbing ability in axial compression, the simulation was carried in ABAQUS /EXPLICIT code. In the simulation part, specimens were prepared and axially crushed to one-fourth length of the tube and the energy diagram of crushing force versus axial displacement is shown. The effect of various parameters such as pitch, mean diameter, corrugation, amplitude, the thickness is demonstrated with the help of diagrams. The overall result shows that the corrugated section geometry could be a good alternative to the conventional tubes.

  19. Manufacture of thin-walled clad tubes by pressure welding of roll bonded sheets

    Science.gov (United States)

    Schmidt, Hans Christian; Grydin, Olexandr; Stolbchenko, Mykhailo; Homberg, Werner; Schaper, Mirko

    2017-10-01

    Clad tubes are commonly manufactured by fusion welding of roll bonded metal sheets or, mechanically, by hydroforming. In this work, a new approach towards the manufacture of thin-walled tubes with an outer diameter to wall thickness ratio of about 12 is investigated, involving the pressure welding of hot roll bonded aluminium-steel strips. By preparing non-welded edges during the roll bonding process, the strips can be zip-folded and (cold) pressure welded together. This process routine could be used to manufacture clad tubes in a continuous process. In order to investigate the process, sample tube sections with a wall thickness of 2.1 mm were manufactured by U-and O-bending from hot roll bonded aluminium-stainless steel strips. The forming and welding were carried out in a temperature range between RT and 400°C. It was found that, with the given geometry, a pressure weld is established at temperatures starting above 100°C. The tensile tests yield a maximum bond strength at 340°C. Micrograph images show a consistent weld of the aluminium layer over the whole tube section.

  20. Radiographic testing methods for welds of thin titanium plates and thin wall tubes

    International Nuclear Information System (INIS)

    1984-01-01

    This standard stipulates the testing method by X-ray radiography for the welded parts of titanium plates and titanium tubes with thickness not exceeding 8 mm. The other items than those stipulated here shall be in accordance with JIS Z 3107-1973 ''Testing method by radiography for the welded part of titanium and method of grade classification of radiographs''. As the photographing method of radiographs, the performance of the equipment and materials for testing, the direction of X-ray irradiation, the thickness of parent materials and welds, the use of penetrameters, the arrangement for photographing, the requirement for radiographs and the observation of radiographs are specified. The X-ray apparatuses, photo-sensitive materials and the tools for photographing and observation must be such that the radiographs clearly showing the defects in the welds being tested can be taken or observed. The JIS Z 3107 is insufficient for the test of thin materials like titanium, therefore, this standard was set down. As the thickness of welds, the thickness of parent materials was taken. In this standard, the titanium penetrameters were adopted because they can be made and they conform to practical state. If magnified photographing is carried out with microfocus X-ray apparatuses, precise photographing can be made. (Kako, I.)

  1. Thin walled Nb tubes for suspending test masses in interferometric gravitational wave detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.H. [School of Physics, University of Western Australia, Crawley 6009, WA (Australia)]. E-mail: bhl@physics.uwa.edu.au; Ju, L. [School of Physics, University of Western Australia, Crawley 6009, WA (Australia); Blair, D.G. [School of Physics, University of Western Australia, Crawley 6009, WA (Australia)

    2006-02-13

    In a previous Letter, we have shown that the use of orthogonal ribbons could provide a better mirror suspension technique in interferometric gravitational wave antennas. One of the key improvements presented by the orthogonal ribbon is the reduction in the number of violin string modes in the direction of the laser. We have considered more elaborate geometries in recent simulations and obtained a suspension that provides further reduction in the number of violin string modes in the direction of the laser, as well as in the direction orthogonal to the laser. This thin walled niobium tube suspension exhibits a reduction in the number of violin modes to 5 in each direction up to a frequency of 5 kHz. Furthermore, the violin mode thermal noise peaks can be reduced in amplitude by 30 dB.

  2. Thin walled Nb tubes for suspending test masses in interferometric gravitational wave detectors

    International Nuclear Information System (INIS)

    Lee, B.H.; Ju, L.; Blair, D.G.

    2006-01-01

    In a previous Letter, we have shown that the use of orthogonal ribbons could provide a better mirror suspension technique in interferometric gravitational wave antennas. One of the key improvements presented by the orthogonal ribbon is the reduction in the number of violin string modes in the direction of the laser. We have considered more elaborate geometries in recent simulations and obtained a suspension that provides further reduction in the number of violin string modes in the direction of the laser, as well as in the direction orthogonal to the laser. This thin walled niobium tube suspension exhibits a reduction in the number of violin modes to 5 in each direction up to a frequency of 5 kHz. Furthermore, the violin mode thermal noise peaks can be reduced in amplitude by 30 dB

  3. Guidelines for Selecting Plugs Used in Thin-Walled Tube Drawing Processes of Metallic Alloys

    Directory of Open Access Journals (Sweden)

    Eva María Rubio

    2017-12-01

    Full Text Available In this paper, some practical guidelines to select the plug or set of plugs more adequate to carry out drawing processes of thin-walled tubes carried out with fixed conical inner plug are presented. For this purpose, the most relevant input parameters have been considered in this study: the tube material, the most important geometrical parameters of the process (die semiangle, α , and cross-sectional area reduction, r and the friction conditions (Coulomb friction coefficients, μ 1 , between the die and the tube outer surface, and μ 2 , between the plug and the tube inner surface. Three work-hardening materials are analyzed: the annealed copper UNS C11000, the aluminum UNS A91100, and the stainless steel UNS S34000. The analysis is realized by means of the upper bound method (UBM, modelling the plastic deformation zone by triangular rigid zones (TRZ, under the validated assumption that the process occurs under plane strain conditions. The obtained results allow establishing, for each material, a group of geometrical parameters, friction conditions, a set of plugs that make possible to carry out the process under good conditions, and the optimum plug to carry out the process using the minimum amount of energy. The proposed model is validated by means of an own finite element analysis (FEA carried out under different conditions and, in addition, by other finite element method (FEM simulations and real experiments taken from other researchers found in the literature (called literature simulations and literature experimental results, respectively. As a main conclusion, it is possible to affirm that the plug that allows carrying out the process with minimum quantity of energy is cylindrical in most cases.

  4. Thin chest wall is an independent risk factor for the development of pneumothorax after chest tube removal.

    Science.gov (United States)

    Anand, Rahul J; Whelan, James F; Ferrada, Paula; Duane, Therese M; Malhotra, Ajai K; Aboutanos, Michel B; Ivatury, Rao R

    2012-04-01

    The factors contributing to the development of pneumothorax after removal of chest tube thoracostomy are not fully understood. We hypothesized that development of post pull pneumothorax (PPP) after chest tube removal would be significantly lower in those patients with thicker chest walls, due to the "protective" layer of adipose tissue. All patients on our trauma service who underwent chest tube thoracostomy from July 2010 to February 2011 were retrospectively reviewed. Patient age, mechanism of trauma, and chest Abbreviated Injury Scale score were analyzed. Thoracic CTs were reviewed to ascertain chest wall thickness (CW). Thickness was measured at the level of the nipple at the midaxillary line, as perpendicular distance between skin and pleural cavity. Chest X-ray reports from immediately prior and after chest tube removal were reviewed for interval development of PPP. Data are presented as average ± standard deviation. Ninety-one chest tubes were inserted into 81 patients. Patients who died before chest tube removal (n = 11), or those without thoracic CT scans (n = 13) were excluded. PPP occurred in 29.9 per cent of chest tube removals (20/67). When PPP was encountered, repeat chest tube was necessary in 20 per cent of cases (4/20). After univariate analysis, younger age, penetrating mechanism, and thin chest wall were found to be significant risk factors for development of PPP. Chest Abbreviated Injury Scale score was similar in both groups. Logistic regression showed only chest wall thickness to be an independent risk factor for development of PPP.

  5. A Study On Critical Thinning In Thin-walled Tube Bending Of Al-Alloy 5052O Via Coupled Ductile Fracture Criteria

    International Nuclear Information System (INIS)

    Li Heng; Yang He; Zhan Mei

    2010-01-01

    Thin-walled tube bending(TWTB) method of Al-alloy tube has attracted wide applications in aerospace, aviation and automobile,etc. While, under in-plane double tensile stress states at the extrados of bending tube, the over-thinning induced ductile fracture is one dominant defect in Al-alloy tube bending. The main objective of this study is to predict the critical wall-thinning of Al-alloy tube bending by coupling two ductile fracture criteria(DFCs) into FE simulation. The DFCs include Continuum Damage Mechanics(CDM)-based model and GTN porous model. Through the uniaxial tensile test of the curved specimen, the basic material properties of the Al-alloy 5052O tube is obtained; via the inverse problem solution, the damage parameters of both the two fracture criteria are interatively determined. Thus the application study of the above DFCs in the TWTB is performed, and the more reasonable one is selected to obtain the critical thinning of Al-alloy tube in bending. The virtual damage initiation and evolution (when and where the ductile fracture occurs) in TWTB are investigated, and the fracture mechanisms of the voided Al-alloy tube in tube bending are consequently discussed.

  6. The influence of triggers geometry upon the stiffness of cylindrical thin walled tubes

    Science.gov (United States)

    Soica, Adrian; Radu, Gheorghe N.

    2014-06-01

    Today's automobile manufacturers are increasingly using lightweight materials to reduce weight; these include plastics, composites, aluminium, magnesium alloys, and also new types of high strength steels. Many of these materials have limited strength or ductility, therefore in many cases the rupture being serious consequences during crashes, underscore Picketta et al. in their studies. Automotive structures must deform plastically in a short period of time, a few milliseconds, to absorb the crash energy in a controllable manner. It must be light and enable economically mass-production [1]. FE models rapidly gained acceptance among engineers. Many other factors facilitated the development of vehicle models by shell finite elements since most of the geometry of the structural surfaces was already on computer graphic files. Kee Poong Kim and Hoon Huh emphasize that the crashworthiness of each vehicle part needs to be evaluated at the initial stage of design for good performance of an assembled vehicle. As the dynamic behaviour of structural members is different from the static one, the crashworthiness of the vehicle structures has to be assessed by impact analysis. The paper analyzes the influence of trigger geometry upon the compression of thin-walled cylindrical tubes. Simulations performed on a simple model showed the dependence between triggers area and deformation times as well as the maximum deformations obtained for various speeds at which the simulations ware carried out. Likewise, the geometry of trigger leads to different results.

  7. Study of tensile test behavior of austenitic stainless steel type 347 seamless thin-walled tubes in cold worked condition

    Energy Technology Data Exchange (ETDEWEB)

    Terui, Clarice, E-mail: clarice.terui@marinha.mil.br [Centro Tecnológico da Marinha em São Paulo (CINA/CTMSP), Iperó, SP (Brazil). Centro Industrial Nuclear da Marinha; Lima, Nelson B. de, E-mail: nblima@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

    2017-07-01

    These austenitic stainless steel type 347 seamless thin-walled tubes are potential candidates to be used in fuel elements of nuclear power plants (as PWR - Pressurized Water Reactor). So, their metallurgical condition and mechanical properties, as the tensile strength and yield strength, normally are very restrict in demanding project and design requirements. Several full size tensile tests at room temperature and high temperature (315 deg C) were performed in these seamless tubes in cold-worked condition. The results of specified tensile and yield strengths were achieved but the elongation of the tube, in the geometry of the component, could not be measured at high temperature due to unconventional mode of rupture (helical mode without separation of parts). The average value of elongation was obtained from stress-strain curves of hot tensile tests and was around 5%. The results obtained in this research show that this behavior of the full size tensile test samples of thin-walled tube (wall thickness less than 0.5 mm) in high temperature (315°C) is due to the combination of the manufacturing process, the material (crystallographic structure and chemical composition) and the final geometry of the component. In other words, the strong crystallographic texture of material induced by tube drawing process in addition with the geometry of the component are responsible for the behavior in hot uniaxial tensile tests. (author)

  8. A tale of two neglected systems - structure and function of the thin- and thick-walled sieve tubes in monocotyledonous leaves.

    Directory of Open Access Journals (Sweden)

    Ted eBotha

    2013-08-01

    Full Text Available There is a large body of information relating to the ontogeny, development and the vasculature of eudicotyledonous leaves. However there is less information available concerning the vascular anatomy of monocotyledonous leaves. This is surprising, given that there are two uniquely different phloem systems present in large groups such as grasses and sedges. Monocotyledonous leaves contain marginal, large, intermediate and small longitudinal veins that are interconnected by numerous transverse veins. The longitudinal veins contain two metaphloem sieve tube types, which, based upon their ontogeny and position within the phloem, are termed early (thin-walled and late (thick-walled sieve tubes. Early metaphloem comprises sieve tubes, companion cells and vascular parenchyma cells, whilst the late metaphloem, contains thick-walled sieve tubes that lack companion cells. Thick-walled sieve tubes are generally adjacent to, or no more than one cell removed from the metaxylem. Unlike thin-walled sieve tube-companion cell complexes, thick-walled sieve tubes are connected to parenchyma by pore-plasmodesma units and are generally symplasmically isolated from the thin walled sieve tubes. This paper addresses key structural and functional differences between thin- and thick-walled sieve tubes and explores the unique advantages of alternate transport strategies that this 5 to 7 million year old dual system may offer. It would seem that these two systems may enhance, add to, or play a significant role in increasing the efficiency of solute retrieval as well as of assimilate transfer.

  9. The thin-wall tube drift chamber operating in vacuum (prototype)

    Science.gov (United States)

    Alexeev, G. D.; Glonti, L. N.; Kekelidze, V. D.; Malyshev, V. L.; Piskun, A. A.; Potrbenikov, Yu. K.; Rodionov, V. K.; Samsonov, V. A.; Tokmenin, V. V.; Shkarovskiy, S. N.

    2013-08-01

    The goal of this work was to design drift tubes and a chamber operating in vacuum, and to develop technologies for tubes independent assembly and mounting in the chamber. These design and technology were tested on the prototype. The main features of the chamber are the following: the drift tubes are made of flexible mylar film (wall thickness 36 μm, diameter 9.80 mm, length 2160 mm) using ultrasonic welding along the generatrix; the welding device and methods were developed at JINR. Drift tubes with end plugs, anode wires and spacers were completely assembled outside the chamber. "Self-centering" spacers and bushes were used for precise setting of the anode wires and tubes. The assembled tubes were sealed with O-rings in their seats in the chamber which simplified the chamber assembling. Moreover the tube assembly and the chamber manufacture can be performed independently and in parallel; this sufficiently reduces the total time of chamber manufacture and assembling, its cost and allows tubes to be tested outside the chamber. The technology of independent tube assembling is suitable for a chamber of any shape but a round chamber is preferable for operation in vacuum. Single channel amplifier-discriminator boards which are more stable against cross talks were used for testing the tubes. Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum.

  10. The thin-wall tube drift chamber operating in vacuum (prototype)

    International Nuclear Information System (INIS)

    Alexeev, G.D.; Glonti, L.N.; Kekelidze, V.D.; Malyshev, V.L.; Piskun, A.A.; Potrbenikov, Yu.K.; Rodionov, V.K.; Samsonov, V.A.; Tokmenin, V.V.; Shkarovskiy, S.N.

    2013-01-01

    The goal of this work was to design drift tubes and a chamber operating in vacuum, and to develop technologies for tubes independent assembly and mounting in the chamber. These design and technology were tested on the prototype. The main features of the chamber are the following: the drift tubes are made of flexible mylar film (wall thickness 36 μm, diameter 9.80 mm, length 2160 mm) using ultrasonic welding along the generatrix; the welding device and methods were developed at JINR. Drift tubes with end plugs, anode wires and spacers were completely assembled outside the chamber. “Self-centering” spacers and bushes were used for precise setting of the anode wires and tubes. The assembled tubes were sealed with O-rings in their seats in the chamber which simplified the chamber assembling. Moreover the tube assembly and the chamber manufacture can be performed independently and in parallel; this sufficiently reduces the total time of chamber manufacture and assembling, its cost and allows tubes to be tested outside the chamber. The technology of independent tube assembling is suitable for a chamber of any shape but a round chamber is preferable for operation in vacuum. Single channel amplifier-discriminator boards which are more stable against cross talks were used for testing the tubes. Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum

  11. The thin-wall tube drift chamber operating in vacuum (prototype)

    Energy Technology Data Exchange (ETDEWEB)

    Alexeev, G.D. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Glonti, L.N., E-mail: glonti@sunse.jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kekelidze, V.D.; Malyshev, V.L.; Piskun, A.A.; Potrbenikov, Yu.K.; Rodionov, V.K.; Samsonov, V.A.; Tokmenin, V.V.; Shkarovskiy, S.N. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

    2013-08-01

    The goal of this work was to design drift tubes and a chamber operating in vacuum, and to develop technologies for tubes independent assembly and mounting in the chamber. These design and technology were tested on the prototype. The main features of the chamber are the following: the drift tubes are made of flexible mylar film (wall thickness 36 μm, diameter 9.80 mm, length 2160 mm) using ultrasonic welding along the generatrix; the welding device and methods were developed at JINR. Drift tubes with end plugs, anode wires and spacers were completely assembled outside the chamber. “Self-centering” spacers and bushes were used for precise setting of the anode wires and tubes. The assembled tubes were sealed with O-rings in their seats in the chamber which simplified the chamber assembling. Moreover the tube assembly and the chamber manufacture can be performed independently and in parallel; this sufficiently reduces the total time of chamber manufacture and assembling, its cost and allows tubes to be tested outside the chamber. The technology of independent tube assembling is suitable for a chamber of any shape but a round chamber is preferable for operation in vacuum. Single channel amplifier-discriminator boards which are more stable against cross talks were used for testing the tubes. Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum.

  12. State-variable analysis of inelastic deformation of thin-walled tubes. II. Data analysis and simulations

    International Nuclear Information System (INIS)

    Wire, G.L.; Duncan, D.R.; Cannon, N.S.; Johnson, G.D.; Alexopoulos, P.S.; Li, C.Y.

    Inelastic analysis is performed to calculate the deformation of thin-walled, internally pressurized, tube under a variety of loading modes. A state-variable approach was used to describe the material properties. The material parameters of the constitutive equations used were determined based on uniaxial, load relaxation, tensile tests, and internally pressurized tubes under creep and constant-displacement-rate modes of loading. The simulated results were compared with the experimental data. The significance of the comparison is discussed in terms of the validity of a state-variable approach used to describe the deformation properties in mechanical testing

  13. Complete Status Report Documenting Development of Friction Stir Welding for Joining Thin Wall Tubing of ODS Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hoelzer, David T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bunn, Jeffrey R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gussev, Maxim N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    The development of friction stir welding (FSW) for joining thin sections of the advanced oxide dispersion strengthened (ODS) 14YWT ferritic alloy was initiated in Fuel Cycle Research and Development (FCRD), now the Nuclear Technology Research and Development (NTRD), in 2015. The first FSW experiment was conducted in late FY15 and successfully produced a bead-on-plate stir zone (SZ) on a 1 mm thick plate of 14YWT (SM13 heat). The goal of this research task is to ultimately demonstrate that FSW is a feasible method for joining thin wall (0.5 mm thick) tubing of 14YWT.

  14. Ultrasonic inspection of steam generator tubing for cracks, wall thinning and cross-sectional deformation

    International Nuclear Information System (INIS)

    Meyer, P.A.; Carodiskey, T.J.

    1988-01-01

    Periodic inspection of steam generator tubing is an important consideration in the efficient operation of a power generating facility. Since the operating life of these generators is finite, failures will occur. Due to the chemistry of the environment, thermal cycling, and other factors, flaws may develop that can cause rapid deterioration of the tubing while the overall performance of the unit may appear normal. In earlier presentation, the authors presented an ultrasonic bore-side array transducer which can be used with a conventional flaw detector instrument for the location of circumferential crack type defects on the outside tube surface. since that time, much additional experience has been gained on the performance of these probes. Probe performance has been characterized using fatigue crack samples and these results are reviewed. Probes have also been developed having 16 elements for use in larger diameter (25 mm) tubes. The bore-side array concept has been expanded to normal incidence tube well inspection allowing simultaneous wall thickness and eccentricity measurement which is very useful in the assessment of tube wastage and deformation. Preliminary data obtained in this area is presented

  15. Complete Status Report Documenting Weld Development for Thin Wall Tubing of ODS Ferritic Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hoelzer, David T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Edmondson, Philip D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gussev, Maxim N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tang, Wei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Feng, Zhili [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-16

    Beginning in 2015, research in the FCRD program began the development of FSW for joining thin sections of 14YWT in the form of thin (0.5 mm) plate and ultimately thin wall tubing. In the previous fiscal year, a ~1 mm thick plate, or sheet, of 14YWT was produced by hot rolling with no edge cracking. The initial FSW experiment was performed on the 1 mm thick plate and involved a bead-on-plate weld in which the spinning pin tool is plunged into the plate surface, but does not penetrate the thickness of the plate, and then travels the length of the plate. The FSW run successfully produced a bead-on-plate stir zone on the 1 mm thick plate of 14YWT, but no characterization studies of the stir zone were performed by the end of FY15. Therefore, the results presented in this report cover the microstructural analysis of the bead-on-plate stir zone and the initial research task on obtaining tensile properties of the stir zone using the digital image correlation (DIC) approach during testing of miniature tensile specimens to assess the quality of the FSW parameters used in the initial experiment. The results of the microstructural characterization study using optical, scanning electron and scanning transmission electron microscopies showed the grain structure in the SZ to have isotropic and irregular shape but very similar size compared to the highly elongated grains oriented horizontally with the plane of the plate that were observed in the unaffected zone of 14YWT. Several cracks oriented horizontally were observed mostly on the retreating side of the SZ in both the SZ and TMAZ. These cracks may have formed due to insufficient pressure being exerted on the top surface of the plate by the shoulder and pin tool during the FSW run. High resolution STEM-EDS analysis showed the presence of the Y-Ti-O particles in the SZ, but that some particles exhibited coarsening. Overall, the FSW parameters used to produce the bead-on-plate SZ in the 0.1 cm thick plate of 14YWT were nearly

  16. A standardized procedure for eddy-current testing of stainless steel, thin-walled nuclear fuel element cladding tubes

    International Nuclear Information System (INIS)

    Barat, P.; Raj, B.; Bhattacharya, D.K.

    1982-01-01

    Thin-walled nuclear fuel cladding tubes made of AISI 316 stainless steel have been examined by eddy-current testing. Standardization of the procedures has required investigations on optimizing the test frequency, finding a method to locate a defect with respect to the probe reference end, and the use of standard defects and sequential metallography of natural defects detected by eddy-current testing, to understand the influence of the nature of defects on the impedance output signals. Test frequency and method of locating the defect were optimized by the use of standard defects made by machining in reference cladding tubes. Subsequent metallography of natural defects detected by eddy-current testing revealed mainly clusters of inclusions but also other types of defects. The effect of the distribution of inclusions along the length of the tube on the impedance output is discussed. (author)

  17. Standardized procedure for eddy-current testing of stainless steel, thin-walled nuclear fuel element cladding tubes

    Energy Technology Data Exchange (ETDEWEB)

    Barat, P; Raj, B; Bhattacharya, D K [Reactor Research Centre, Kalpakkam (India)

    1982-10-01

    Thin-walled nuclear fuel cladding tubes made of AISI 316 stainless steel have been examined by eddy-current testing. Standardization of the procedures has required investigations on optimizing the test frequency, finding a method to locate a defect with respect to the probe reference end, and the use of standard defects and sequential metallography of natural defects detected by eddy-current testing, to understand the influence of the nature of defects on the impedance output signals. Test frequency and method of locating the defect were optimized by the use of standard defects made by machining in reference cladding tubes. Subsequent metallography of natural defects detected by eddy-current testing revealed mainly clusters of inclusions but also other types of defects. The effect of the distribution of inclusions along the length of the tube on the impedance output is discussed.

  18. Design of welding parameters for laser welding of thin-walled stainless steel tubes using numerical simulation

    Science.gov (United States)

    Nagy, M.; Behúlová, M.

    2017-11-01

    Nowadays, the laser technology is used in a wide spectrum of applications, especially in engineering, electronics, medicine, automotive, aeronautic or military industries. In the field of mechanical engineering, the laser technology reaches the biggest increase in the automotive industry, mainly due to the introduction of automation utilizing 5-axial movements. Modelling and numerical simulation of laser welding processes has been exploited with many advantages for the investigation of physical principles and complex phenomena connected with this joining technology. The paper is focused on the application of numerical simulation to the design of welding parameters for the circumferential laser welding of thin-walled exhaust pipes from theAISI 304 steel for automotive industry. Using the developed and experimentally verified simulation model for laser welding of tubes, the influence of welding parameters including the laser velocity from 30 mm.s-1 to 60 mm.s-1 and the laser power from 500 W to 1200 W on the temperature fields and dimensions of fusion zone was investigated using the program code ANSYS. Based on obtained results, the welding schedule for the laser beam welding of thin-walled tubes from the AISI 304 steel was suggested.

  19. Mathematical Model for Thin-walled Corrugated Tube under Axial Compression

    Directory of Open Access Journals (Sweden)

    Eyvazian Arameh

    2016-01-01

    Full Text Available In this research, theoretical investigation of corrugated aluminum tubes is performed to predicting the energy absorption characteristics. Aim to deform plastic tubes in predetermined intervals, corrugations are introduced on its surface. Theoretical relations are presented for predicting the energy absorption and mean crushing load of corrugated tubes. Other than that, corrugation helps to control the failure mode.

  20. Stress in closed thin-walled tubes of single box subjected by shear forces and application to airfoils

    Directory of Open Access Journals (Sweden)

    Zebbiche Toufik

    2014-09-01

    Full Text Available The presented work is to develop a numerical computation program to determine the distribution of the shear stress to shear in closed tubes with asymmetric single thin wall section with a constant thickness and applications to airfoils and therefore determining the position and value of the maximum stress. In the literature, there are exact analytical solutions only for some sections of simple geometries such as circular section. Hence our interest is focused on the search of approximate numerical solutions for more complex sections used in aeronautics. In the second stage the position of the shear center is determined so that the section does not undergo torsion. The analytic function of the boundary of the airfoil is obtained by using the cubic spline interpolation since it is given in the form of tabulated points.

  1. Mount Protects Thin-Walled Glass or Ceramic Tubes from Large Thermal and Vibration Loads

    Science.gov (United States)

    Amato, Michael; Schmidt, Stephen; Marsh. James; Dahya, Kevin

    2011-01-01

    The design allows for the low-stress mounting of fragile objects, like thin walled glass, by using particular ways of compensating, isolating, or releasing the coefficient of thermal expansion (CTE) differences between the mounted object and the mount itself. This mount profile is lower than true full kinematic mounting. Also, this approach enables accurate positioning of the component for electrical and optical interfaces. It avoids the higher and unpredictable stress issues that often result from potting the object. The mount has been built and tested to space-flight specifications, and has been used for fiber-optic, optical, and electrical interfaces for a spaceflight mission. This mount design is often metal and is slightly larger than the object to be mounted. The objects are optical or optical/electrical, and optical and/or electrical interfaces are required from the top and bottom. This requires the mount to be open at both ends, and for the object s position to be controlled. Thin inside inserts at the top and bottom contact the housing at defined lips, or edges, and hold the fragile object in the mount. The inserts can be customized to mimic the outer surface of the object, which further reduces stress. The inserts have the opposite CTE of the housing material, partially compensating for the CTE difference that causes thermal stress. A spring washer is inserted at one end to compensate for more CTE difference and to hold the object against the location edge of the mount for any optical position requirements. The spring also ensures that any fiber-optic or optic interface, which often requires some pressure to ensure a good interface, does not overstress the fragile object. The insert thickness, material, and spring washer size can be traded against each other to optimize the mount and stresses for various thermal and vibration load ranges and other mounting requirements. The alternate design uses two separate, unique features to reduce stress and hold the

  2. Analysis of the ballooning deformation of an internally pressurized thin-wall tube during fast thermal transients

    International Nuclear Information System (INIS)

    Lin, E.I.H.

    1977-01-01

    A large-strain time-dependent thermoplastic analysis has been developed for the ballooning deformation of a thin-wall tube subjected to internal pressure, axial loading, and fast thermal transients. This deformation initiates with the onset of plastic instability in the material, the onset being determined by a plastic-instability criterion for strain-rate sensitive materials. The interaction among the local ballooning geometry, the state of stress, and the plastic flow process was considered, and integration of the flow equations yields the local curvature and the states of stress and strain in the vicinity of the maximum ballooning site. The effects of axial constraint and heating rate were also discussed. The analysis was applied to a LWR Zircaloy cladding subjected to a constant heating rate and a range of internal pressures. The results agree very well with experimental strain-time data obtained from tube-burst tests. In most cases, the time of rupture was accurately predicted despite the lack of complete material-property data

  3. Nonlinear optical properties of polyaniline and poly (o-toluidine) composite thin films with multi walled carbon nano tubes

    Energy Technology Data Exchange (ETDEWEB)

    Nagaraja, K.K. [National University of Science and Technology “MISiS”, Leninskii pr. 4, Moscow 119049 (Russian Federation); Pramodini, S. [Department of Physics, School of Engineering and Technology, Jain University, Jakkasandra Post, Bengaluru 5621112, Karnataka (India); Poornesh, P., E-mail: poorneshp@gmail.com [Nonlinear Optics Research Laboratory, Department of Physics, Manipal Institute of Technology, Manipal University, Manipal 576 104, Karnataka (India); Telenkov, M.P. [National University of Science and Technology “MISiS”, Leninskii pr. 4, Moscow 119049 (Russian Federation); Kityk, I.V. [Electrical Engineering Department, Czestochowa University Technology, Czestochowa (Poland)

    2017-05-01

    We report the improved third-order nonlinear optical properties of polyaniline and poly (o-toluidine) with different doping concentrations of multi walled carbon nano tube (MWCNTs) composite thin films investigated using z-scan technique and continuous wave He–Ne laser at 633 nm wavelength was used as source of excitation. Thin films were prepared by spin coating technique on glass substrate. The structural properties of the composite films were analysed by X-ray diffraction studies and the characteristic peaks corresponding to MWCNTs and polymers have been observed. The surface morphology of the deposited films was analysed using scanning electron microscopy and it confirms that the polymer in the composites has been coated on the MWCNTs homogeneously. The z-scan results reveal that the films exhibit reverse saturable absorption and self-defocusing nonlinearity. The third-order nonlinear optical susceptibility χ{sup (3)} is found to be of the order of 10{sup −3} esu. Also, optical power limiting and clamping experiment was performed. The clamping values increases with increase in concentration and the lowest clamping observed for composite films are 1 mW and 0.7 mW.

  4. Fatigue of thin walled tubes in copper alloy CuNi10

    DEFF Research Database (Denmark)

    Lambertsen, Søren Heide; Damkilde, Lars; Jepsen, Michael S.

    2016-01-01

    The current work concerns the investigation of the fatigue resistance of CuNi10 tubes, which are frequently used in heat exchangers of large ship engines. The lifetime performances of the exchanger tubes are greatly affected by the environmental conditions, where especially the temperature...... by means of the ASTM E739 guideline and one-sided tolerance limits factor method. The tests show good fatigue resistance and the risk for a failure is low in aspect to the case of a ship heat exchanger....

  5. Double wall steam generator tubing

    International Nuclear Information System (INIS)

    Padden, T.R.; Uber, C.F.

    1983-01-01

    Double-walled steam generator tubing for the steam generators of a liquid metal cooled fast breeder reactor prevents sliding between the surfaces due to a mechanical interlock. Forces resulting from differential thermal expansion between the outer tube and the inner tube are insufficient in magnitude to cause shearing of base metal. The interlock is formed by jointly drawing the tubing, with the inside wall of the outer tube being already formed with grooves. The drawing causes the outer wall of the inner tube to form corrugations locking with the grooves. (author)

  6. Low-cost fabrication of thin-walled solid electrolyte tubes from doctor-bladed ceramic tape

    Energy Technology Data Exchange (ETDEWEB)

    Dirstine, R T

    1979-01-01

    Sodium ..beta..-Al/sub 2/O/sub 3/ tubes having wall thicknesses of typically 0.4 mm were fabricated from doctor-bladed (cast) ceramic tape by use of proprietary organic slip compositions and zeta-processed, lithia-stabilized alumina power. The ceramic tubes fabricated from cast tape had low porosity, low resistivity (approx. 4 ohm-cm at 300/sup 0/C), and good mechanical strength. Alternative fabrication techniques for manufacture of tubes from tape were evaluated, and the primary processing requirements/obstacls were identified. Closed-end tubes, nominally 10 mm outer diameter, 60 mm in length, and with a wall thickness of 0.3 mm, were supplied to the Department of Energy. 26 figures, 10 tables.

  7. Thin-walled composite tubes using fillers subjected to quasistatic axial compression

    International Nuclear Information System (INIS)

    AL-Qrimli, Haidar F; Mahdi, Fadhil A; Ismail, Firas B; Alzorqi, Ibrahim S

    2015-01-01

    It has been demonstrated that composites are lightweight, fatigue resistant and easily melded, a seemingly attractive alternative to metals. However, there has been no widespread switch from metals to composites in the automotive sector. This is because there are a number of technical issues relating to the use of composite materials that still need to be resolved including accurate material characterization, manufacturing and joining process. The total of 36 specimens have been fabricated using the fibre-glass and resin (epoxy) with a two different geometries (circular and corrugated) each one will be filled with five types of filler (Rice Husk, Wood Chips, Aluminium Chips, Coconut Fibre, Palm Oil Fibre) all these type will be compared with empty Tubes for circular and corrugated in order to comprehend the crashworthiness parameters (initial failure load, average load, maximum crushing load, load ratio, energy absorption, specific energy absorption, volumetric energy absorption, crushing force efficiency and crush strain relation) which are considered very sufficient parameters in the design of automotive industry parts. All the tests have been done using the “INSTRON Universal machine” which is computerized in order to simply give a high precision to the collection of the results, along with the use of quasi-static load to test and observe the behaviour of the fabricated specimens. (paper)

  8. Thin-walled composite tubes using fillers subjected to quasistatic axial compression

    Science.gov (United States)

    AL-Qrimli, Haidar F.; Mahdi, Fadhil A.; Ismail, Firas B.; Alzorqi, Ibrahim S.

    2015-04-01

    It has been demonstrated that composites are lightweight, fatigue resistant and easily melded, a seemingly attractive alternative to metals. However, there has been no widespread switch from metals to composites in the automotive sector. This is because there are a number of technical issues relating to the use of composite materials that still need to be resolved including accurate material characterization, manufacturing and joining process. The total of 36 specimens have been fabricated using the fibre-glass and resin (epoxy) with a two different geometries (circular and corrugated) each one will be filled with five types of filler (Rice Husk, Wood Chips, Aluminium Chips, Coconut Fibre, Palm Oil Fibre) all these type will be compared with empty Tubes for circular and corrugated in order to comprehend the crashworthiness parameters (initial failure load, average load, maximum crushing load, load ratio, energy absorption, specific energy absorption, volumetric energy absorption, crushing force efficiency and crush strain relation) which are considered very sufficient parameters in the design of automotive industry parts. All the tests have been done using the “INSTRON Universal machine” which is computerized in order to simply give a high precision to the collection of the results, along with the use of quasi-static load to test and observe the behaviour of the fabricated specimens.

  9. Failure analysis of the boiler water-wall tube

    OpenAIRE

    S.W. Liu; W.Z. Wang; C.J. Liu

    2017-01-01

    Failure analysis of the boiler water-wall tube is presented in this work. In order to examine the causes of failure, various techniques including visual inspection, chemical analysis, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy were carried out. Tube wall thickness measurements were performed on the ruptured tube. The fire-facing side of the tube was observed to have experienced significant wall thinning. The composition of the matrix material of the tu...

  10. Influence of Mn contents in 0Cr18Ni10Ti thin wall stainless steel tube on TIG girth weld quality

    Science.gov (United States)

    Liu, Bo

    2017-03-01

    Three kinds of cold worked 0Cr18Ni10Ti thin wall stainless steel tubes with the manganese contents of 1.27%, 1.35% and 1.44% and the cold worked 0Cr18Ni10Ti stainless steel end plug with manganese content of 1.35% were used for TIG girth welding in the present investigation. The effect of different manganese contents in stainless steel tube on weld quality was studied. The results showed that under the same welding conditions, the metallographic performance of the girth weld for the thin wall stainless steel tube with the manganese element content 1.44% welded with end plug was the best. Under the appropriate welding conditions, the quality of the girth weld increased with the increase of the manganese content till 1.44%. It was found that in the case of the Mn content of 1.44%, and under the proper welding condition the welding defects, such as welding cracks were effectively avoided, and the qualified weld penetration can be obtained.. It is concluded that the appropriate increase of the manganese content can significantly improve the TIG girth weld quality of the cold worked 0Cr18Ni10Ti stainless steel tube.

  11. Failure analysis of the boiler water-wall tube

    Directory of Open Access Journals (Sweden)

    S.W. Liu

    2017-10-01

    Full Text Available Failure analysis of the boiler water-wall tube is presented in this work. In order to examine the causes of failure, various techniques including visual inspection, chemical analysis, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy were carried out. Tube wall thickness measurements were performed on the ruptured tube. The fire-facing side of the tube was observed to have experienced significant wall thinning. The composition of the matrix material of the tube meets the requirements of the relevant standards. Microscopic examinations showed that the spheroidization of pearlite is not very obvious. The failure mechanism is identified as a result of the significant localized wall thinning of the boiler water-wall tube due to oxidation.

  12. Room temperature elastic--plastic response of thin-walled tubes subjected to nonradial combinations of axial and torsional loadings

    International Nuclear Information System (INIS)

    Liu, K.C.

    1975-01-01

    Two tubular specimens of type 304 stainless steel with uniform thin walls were subjected to a program of segmental combined tension/compression and torsion loadings at room temperature. A proportional, or radial, loading into the plastic range was initially applied to each specimen. Two nonproportional (nonradial) loadings along straight line segments for which neither the loading paths nor their linear extrapolations passed through the origin of the stress space were then applied. The axial and torsional stress-strain curves for these segmental prestress loadings were plotted. Hence, the stress-strain response characteristics for nonproportional loadings as well as for proportional loading can be studied. In addition, the axial and torsional plastic strain components were calculated, and the total plastic strain trajectories were plotted in a plastic strain space. Finally, using results from a detailed study of yield surfaces, which was performed for the first specimen, a spectrum of initial and subsequent yield curves corresponding to the segmental prestress loadings is presented. (U.S.)

  13. Integrated straight - through automatic non-destructive examination and data acquisition system for thin-wall tubes

    International Nuclear Information System (INIS)

    Stoessel, A.; Boulanger, G.; Furlan, J.; Mogavero, R.

    1981-09-01

    This non-destructive testing unit inspects the cladding tubes for the SUPER-PHENIX fast neutron reactor. The quality level demanded for these tubes, as well as their number, required designing an installation that combined high performance with a great testing rate and complete automation. The testing is effected under immersion by means of six transducers, focused in line, working at 30 MHz. The tubes are numbered on an automatic rig; marking is by dark rings obtained by superficial electrolysis of the tube and regularly distributed on the abscissa; the quality of the tube is not affected by this. The advantage of this numbering system is that it enables the tubes to be fed to the test set in any order. An acquisition unit, constituted of a microprocessor, a semi-graphical printer and a double floppy disk unit, makes it possible to enter, edit and store the information for each tube [fr

  14. Analysis of the ballooning deformation of an internally pressurized thin-wall tube during fast thermal transients

    International Nuclear Information System (INIS)

    Lin, E.I.H.

    1977-01-01

    A large-strain, time-dependent thermoplastic analysis of ballooning deformation was developed. The true (or lagorithmic) strains, the Von Mises yield criterion and Prandtl-Reuss flow rules were used. The constitutive equation was expressed in terms of the temperature, effective stress, strain and strain rate. Material isotropy was assumed as a first approximation; note that at high temperatures even zircaloy tends to lose a substantial amount of its low-temperature anisotropy. The axisymmetry of ballooning was also assumed, which has actually been verified by numerous experiments to be accurate throughout the course of ballooning, except in the final stage when rupture is imminent. The thin-shell approximation was made, which proved to be adequate for the standard fuel claddings and which was advantageous in that the averaged state of stress was rendered determinate. The analysis led to a set of non-linear ordinary differential equations, which was then integrated by a fifth-order Runge-Kutta routine. The general formulation allows for a direct interpretation of the experimentally-observed effects of the heating rate and cladding axial constraints on the ballooning behavior. Its implications on the flow-blockage and cladding-rupture evaluations were discussed. The analysis was applied to zircaloy claddings subjected to simulated thermal transient conditions. Most of the required material properties were taken from the existing uniaxial tensile test data. Analyses were performed at a uniform heating rate of 115 0 C/sec with internal pressures ranging from 100 to 1200 psi. Satisfactory agreement was obtained between the predictions and the diametral strain-time data available from tube-burst tests

  15. Collapse of thin wall tubes small initial ovality; Colapso de tubos de pared delgada con pequena ovalidad inicial

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, A

    1977-07-01

    In this work a simple model of creep collapse of tubes based on the bending theory of curved beams, is developed. The model is compared with more complex models. The main result of this work is the definition of a new model of creep collapse of tubes with a minimum of limitative hypothesis. (Author) 6 refs.

  16. Investigation of Mild Steel Thin-Wall Tubes in Unfilled and Foam-Filled Triangle, Square, and Hexagonal Cross Sections Under Compression Load

    Science.gov (United States)

    Rajak, Dipen Kumar; Kumaraswamidhas, L. A.; Das, S.

    2018-02-01

    This study has examined proposed structures with mild steel-reinforced LM30 aluminum (Al) alloy having diversely unfilled and 10 wt.% SiCp composite foam-filled tubes for improving axial compression performance. This class of material has novel physical, mechanical, and electrical properties along with low density. In the present experiment, Al alloy foams were prepared by the melt route technique using metal hydride powder as a foaming agent. Crash energy phenomena for diverse unfilled and foam-filled in mild steel thin-wall tubes (triangular, square and hexagonal) were studied as well. Compression deformation investigation was conducted at strain rates of 0.001-0.1/s for evaluating specific energy absorption (SEA) under axial loading conditions. The results were examined to measure plateau stress, maximum densification strain, and deformation mechanism of the materials. Specific energy absorption and total energy absorption capacities of the unfilled and filled sections were determined from the compressive stress-strain curves, which were then compared with each other.

  17. Convective heat transport of high-pressure flows inside active, thick walled-tubes with isothermal outer surfaces: usage of Nusselt correlation equations for an inactive, thin walled-tube

    Energy Technology Data Exchange (ETDEWEB)

    Campo, Antonio [Idaho State Univ., Nuclear Engineering Dept., Pocatello, ID (United States); Sanchez, Alejo [Universidad de los Andes, Depto. de Ingenieria Mecanica, Merida (Venezuela)

    1998-03-01

    A semi-analytical analysis was conducted for the prediction of the mean bulk- and interface temperatures of gaseous and liquid fluids moving laminarly at high pressures inside thick-walled metallic tubes. The outer surfaces of the tubes are isothermal. The central goal of this article is to critically examine the thermal response of this kind of in-tube flows utilizing two versions of the 1-D lumped model: one is differential-numerical while the other is differential-algebraic. For the former, the local Nusselt number characterizing an inactive, isothermal tube was taken from correlation equations reported in the heat transfer literature. For the latter, a streamwise-mean Nusselt number associated with an active, isothermal tube was taken from standard correlation equations that appear in text-books on basic heat transfer. For the two different versions of the 1-D lumped model tested, the computed results consistently demonstrate that the differential-algebraic, provides accurate estimates of both the mean bulk- and the interface temperatures when compared with those temperature results computed with formal 2-D differential models. (author)

  18. Full Scale Measurements and CFD Investigations of a Wall Radiant Cooling System Based on Plastic Capillary Tubes in Thin Concrete Walls

    DEFF Research Database (Denmark)

    Mikeska, Tomás; Fan, Jianhua; Svendsen, Svend

    2017-01-01

    Densely occupied spaces such as classrooms can very often have problems with overheating. It can be difficult to cool such spaces by means of a ventilation system without creating draughts and causing discomfort for occupants. The use of a wall radiant cooling system is a suitable option for spaces...

  19. Analytic model of the stress waves propagation in thin wall tubes, seeking the location of a harmonic point source in its surface

    International Nuclear Information System (INIS)

    Boaratti, Mario Francisco Guerra

    2006-01-01

    Leaks in pressurized tubes generate acoustic waves that propagate through the walls of these tubes, which can be captured by accelerometers or by acoustic emission sensors. The knowledge of how these walls can vibrate, or in another way, how these acoustic waves propagate in this material is fundamental in the detection and localization process of the leak source. In this work an analytic model was implemented, through the motion equations of a cylindrical shell, with the objective to understand the behavior of the tube surface excited by a point source. Since the cylindrical surface has a closed pattern in the circumferential direction, waves that are beginning their trajectory will meet with another that has already completed the turn over the cylindrical shell, in the clockwise direction as well as in the counter clockwise direction, generating constructive and destructive interferences. After enough time of propagation, peaks and valleys in the shell surface are formed, which can be visualized through a graphic representation of the analytic solution created. The theoretical results were proven through measures accomplished in an experimental setup composed of a steel tube finished in sand box, simulating the condition of infinite tube. To determine the location of the point source on the surface, the process of inverse solution was adopted, that is to say, known the signals of the sensor disposed in the tube surface , it is determined through the theoretical model where the source that generated these signals can be. (author)

  20. Gas target with thin wall

    International Nuclear Information System (INIS)

    Korenchenko, A.S.; Korenchenko, S.M.; Kravchuk, N.P.; Filippov, A.I.; Fursov, A.P.

    1992-01-01

    The technology of targets manufacture with thin wall diameter 100 mm and lengthwise 700 mm from composition kevlar + epoxy resin is described. The test's results on pressure and vacuum are reported. The created targets are supposed to be used on the installation ARES for an investigation of muons and pions interactions with light nuclei and rare pions decay 'on flying'. 5 refs.; 2 figs.; 2 tabs

  1. Wall thickness measurements of tubes by Internal Rotary Inspection System (IRIS)- a comparative study with metallography

    International Nuclear Information System (INIS)

    Subramanian, C.V.; Joseph, A.; Ramesh, A.S.; Jayakumar, T.; Kalyanasundaram, P.; Baldev Raj

    1996-01-01

    Internal Rotary Inspection System (IRIS) is a relatively new ultrasonic system of heat exchanger/ steam condenser tubes and pipelines for measurement of wall thinning and pitting due to corrosion. The wall thickness measurements made during a scan around the circumference of the tube are displayed as a stationary rectilinear display of circumferential cross section (Bscan) of the tube. The paper describes the results obtained on tubes of various materials used in process industries having corrosion on inner and outer surfaces of the tube. (author)

  2. Positioning a thin-wall round wrapper within a heavy wall out-of-round shell of a heat exchanger

    International Nuclear Information System (INIS)

    Hargrove, H.G.; Thompson, E.G.; Bayless, J.R.

    1983-01-01

    A thin-wall, generally round wrapper is installed within a heavy wall, rolled heat exchanger shell which has greater out-of-round tolerances than the wrapper and the wrapper is maintained in its round state by utilizing a plurality of jacks disposed adjacent spaced tube support plates within the wrapper. (author)

  3. Evaluation of wall thinning profile by flow accelerated corrosion in separation and union pipe

    International Nuclear Information System (INIS)

    Watanabe, Shun; Yoneda, Kimitoshi

    2013-01-01

    Flow Accelerated Corrosion (FAC) is a pipe wall thinning phenomena to be monitored and managed in power plants with high priority. At present, its management has been conducted with conservative evaluation of thinning rate and residual lifetime of the piping based on wall thickness measurements. However, noticeable case of wall thinning was occurred at separation and union pipe. In such pipe system, it is a problem to manage section beneath reinforcing plate of T-tube pipe and 'crotch' of T-joint pipe; the region where wall thickness measurement is difficult to conduct with ordinary ultrasonic testing device. In this study, numerical analysis for separation and union part of T-tube and T-joint pipe was conducted, and wall thinning profile by Flow Accelerated Corrosion was evaluated by calculating mass transfer coefficient and geometry factor. Based on these results, we considered applicable wall thinning management for T-tube and T-joint pipe. In the case of union flow from main and branch pipe, the wall thinning profile of T-tube showed the tendency of increase at main pipe like semielliptical region. On the other hand, noticeable profile appeared at 'crotch' in T-joint. Although it was found that geometry factor of T-joint in this case was half the value of T-tube, an alternative evaluation method to previous one might be needed for the profiles of 'semielliptical region' and 'crotch'. (author)

  4. Thin walls in regions with vacuum energy

    Energy Technology Data Exchange (ETDEWEB)

    Garfinkle, D [Florida Univ., Gainesville, FL (USA). Dept. of Physics; Vuille, C [Embry-Riddle Aeronautical Univ., Prescott, AZ (USA). Dept. of Math/Physical Science

    1989-12-01

    The motion of a thin wall is treated in the case where the regions on either side of the wall have vacuum energy. This treatment generalises previous results involving domain walls in vacuum and also previous results involving the properties of false vacuum bubbles. The equation of state for a domain wall is{tau} = {sigma} where {tau} is the tension in the wall and {sigma} is the energy density. We consider the motion of a more general class of walls having equation of state {tau}{Gamma}{sigma} with 0{le}{Gamma}{le}1. Spherically symmetric and planar symmetric walls are examined. We also find the global structure of the wall spacetime. (author).

  5. Tank wall thinning -- Process and programs

    International Nuclear Information System (INIS)

    Greer, S.D.; McBrine, W.J.

    1994-01-01

    In-service thinning of tank walls has occurred in the power industry and can pose a significant risk to plant safety and dependability. Appropriate respect for the energy stored in a high-pressure drain tank warrants a careful consideration of this possibility and appropriate action in order to assure the adequate safety margins against leakage or rupture. Although it has not proven to be a widespread problem, several cases of wall thinning and at least one recent tank rupture has highlighted this issue in recent years, particularly in nuclear power plants. However, the problem is not new or unique to the nuclear power industry. Severe wall thinning in deaerator tanks has been frequently identified at fossil-fueled power plants. There are many mechanisms which can contribute to tank wall thinning. Considerations for a specific tank are dictated by the system operating conditions, tank geometry, and construction material. Thinning mechanisms which have been identified include: Erosion/Corrosion Impingement Erosion Cavitation Erosion General Corrosion Galvanic Corrosion Microbial-induced Corrosion of course there are many other possible types of material degradation, many of which are characterized by pitting and cracking. This paper specifically addresses wall thinning induced by Erosion/Corrosion (also called Flow-Accelerated Corrosion) and Impingement Erosion of tanks in a power plant steam cycle. Many of the considerations presented are applicable to other types of vessels, such as moisture separators and heat exchangers

  6. Thin tube testing by eddy currents

    International Nuclear Information System (INIS)

    David, Bernard; Pigeon, Michel

    1981-01-01

    It is often necessary to define test conditions in eddy current testing, in consequence rules and laws allowing a rapid choice of these conditions are welcome. The similarity law, given by Forster, using the reduced frequency f/fg, allows extrapolation of results from an object to one another, if these two objects are similar (i.e. all their dimensions are proportional). In a particular case, often met, a law going further is given to describe, in a sole way, eddy current behaviour using the reduced frequency in all thin tubes (internal to external diameter ratio between 0.85 to 1). For instance working at f/fe=2 defines the same verification leading to identical results, whatever the nature, the diameter or the thickness may be, if the tubes are thin. A diagram is given and a slide-rule, based on this principle, has been realized [fr

  7. Stability of spiral welded tubes in Quay Walls

    NARCIS (Netherlands)

    Gresnigt, A.M.; van Es, S.H.J.

    2013-01-01

    A European research project (RFCS) has started to provide economic and safe guidance for the design of spirally welded tubes in combined walls. The main motivation for this project called COMBITUBE is that the current Eurocode 3 regulations for tubes in quay walls lead to uneconomic designs, because

  8. Wall thinning of piping in power plants

    International Nuclear Information System (INIS)

    Ohta, Joji; Inada, Fumio; Morita, Ryo; Kawai, Noboru; Yoneda, Kimitoshi

    2005-01-01

    Major mechanisms causing wall thinning of piping in power plants are flow accelerated corrosion (FAC), cavitation erosion and droplet erosion. Their fundamental aspects are reviewed on the basis of literature data. FAC is chemical process and it is affected by hydrodynamic factors, temperature, pH, dissolved oxygen concentration and chemical composition of materials. On the other hand, cavitation erosion and droplet erosion are mechanical process and they are mainly affected by hydrodynamic factors and mechanical properties of materials. Evaluation codes for FAC and mitigation methods of FAC and the erosion are also described. Wall thinning of piping is one of public concerns after an accident of a pipe failure at Mihama Nuclear Power Plant Unit 3, Kansai Electric Power Co., Inc., in August 2004. This paper gives comprehensive understanding of the wall thinning mechanism. (author)

  9. Enhanced Hot Tensile Ductility of Mg-3Al-1Zn Alloy Thin-Walled Tubes Processed Via a Combined Severe Plastic Deformation

    Science.gov (United States)

    Fata, A.; Eftekhari, M.; Faraji, G.; Mosavi Mashhadi, M.

    2018-05-01

    In the current study, combined parallel tubular channel angular pressing (PTCAP) and tube backward extrusion (TBE), as a recently developed severe plastic deformation (SPD) method, were applied at 300 °C on a commercial Mg-3Al-1Zn alloy tubes to achieve an ultrafine grained structure. Then, the microstructure, hardness, tensile properties, and fractography evaluations were done at room temperature on the SPD-processed samples. Also, to study the hot tensile ductility of the SPD-processed samples, tensile testing was performed at an elevated temperature of 400 °C, and then, the fractured surface of the tensile samples was studied. It was observed that a bimodal microstructure, with large gains surrounded by many tiny ones, was created in the sample processed by PTCAP followed by TBE. This microstructure led to reach higher hardness and higher strength at room temperature and also led to reach very high elongation to failure ( 181%) at 400 °C. Also, the value of elongation to failure for this sample was 14.1% at room temperature. The fractographic SEM images showed the occurrence of predominately ductile fracture in the samples pulled at 400 °C. This was mostly due to the nucleation of microvoids and their subsequent growth and coalescence with each other.

  10. Cell Wall Composition, Biosynthesis and Remodeling during Pollen Tube Growth

    Directory of Open Access Journals (Sweden)

    Jean-Claude Mollet

    2013-03-01

    Full Text Available The pollen tube is a fast tip-growing cell carrying the two sperm cells to the ovule allowing the double fertilization process and seed setting. To succeed in this process, the spatial and temporal controls of pollen tube growth within the female organ are critical. It requires a massive cell wall deposition to promote fast pollen tube elongation and a tight control of the cell wall remodeling to modify the mechanical properties. In addition, during its journey, the pollen tube interacts with the pistil, which plays key roles in pollen tube nutrition, guidance and in the rejection of the self-incompatible pollen. This review focuses on our current knowledge in the biochemistry and localization of the main cell wall polymers including pectin, hemicellulose, cellulose and callose from several pollen tube species. Moreover, based on transcriptomic data and functional genomic studies, the possible enzymes involved in the cell wall remodeling during pollen tube growth and their impact on the cell wall mechanics are also described. Finally, mutant analyses have permitted to gain insight in the function of several genes involved in the pollen tube cell wall biosynthesis and their roles in pollen tube growth are further discussed.

  11. Connection of thin-walled casings

    Energy Technology Data Exchange (ETDEWEB)

    Druyan, V.M.; Grinev, A.F.; Gruzdev, V.D.; Perchanik, V.V.; Syplenko, V.T.

    1981-08-28

    A connection is suggested for castings which contains a nipple and coupling part with conical triangular threading. in order to improve the strength of the connection of thin-walled casings with ratio D/S>22, where D is the outer diameter of the casing, S is the thickness of the wall of the casing, the end of the pipe on the length from the end to the main plane of the thread is conical with constant thickness of the wall and conicity eqal to the conicity of the thread.

  12. Evaluation of wall thinning of piping with reinforcing plates using ECT with controlled exciting field

    International Nuclear Information System (INIS)

    Ichihara, Toshiaki; Xie, Shejuan; Uchimoto, Tetsuya; Takagi, Toshiyuki

    2011-01-01

    No effective inspection method exists at present for detection and evaluation of wall thinning under the reinforcing plates to T-tubes in nuclear power plants, and the establishment of the inspection method is highly required. In this study, eddy current testing (ECT) with controlled exciting field is applied to evaluation of wall thinning under the reinforcing plates of T-tubes, and their feasibility is discussed. In order to induce eddy current field in deep region of doubled plates, pulse excitation and probe structures are investigated. Through experiments using specimens simulating tubes with reinforcing plates, it is shown that pulsed ECT and conventional TR type eddy current probe with optimized configuration have a capability of detecting and sizing the wall thinning under reinforcing plates. (author)

  13. The precision cutting control research of automotive stainless steel thin wall pipe

    Directory of Open Access Journals (Sweden)

    Jin Lihong

    2015-01-01

    Full Text Available Stainless steel thin-walled tube are widely used in automobile industry at present, but as a result of thin wall pipe is poor strength and poor rigidity,which lead to deformation, shaped differencer and other problems in the process, it is hard to ensure the processing quality of parts. This paper proposes a method of thin stainless steel thin wall pipe cutting process in vehicle, greatly improved the problems and technical difficulties in the traditional process, the main research is about the cutting system and the hydraulic fixture design, obtained under low cost circumstances, it can realize high precision stainless steel pipes, high degree of automation to automatic cutting,simplified operation steps at the same time, increased the applicability of the system, provided a kind of advanced stainless steel thin wall pipe cutting device for the small and medium-sized enterprises.

  14. Control of Cell Wall Extensibility during Pollen Tube Growth

    OpenAIRE

    Hepler, Peter K.; Rounds, Caleb M.; Winship, Lawrence J.

    2013-01-01

    Tip-growing pollen tubes achieve rapid elongation while maintaining cell wall integrity by balancing local expansion, controlled by local changes in wall viscosity, against exocytosis, influenced by the activity of the actin cytoskeleton, cellular energetics, and calcium and proton physiology.

  15. Flame oscillations in tubes with nonslip at the walls

    Energy Technology Data Exchange (ETDEWEB)

    Akkerman, V' yacheslav; Bychkov, Vitaly; Petchenko, Arkady [Institute of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Eriksson, Lars-Erik [Department of Applied Mechanics, Chalmers University of Technology, 412 96 Goeteborg (Sweden)

    2006-06-15

    A laminar premixed flame front propagating in a two-dimensional tube is considered with nonslip at the walls and with both ends open. The problem of flame propagation is solved using direct numerical simulations of the complete set of hydrodynamic equations including thermal conduction, diffusion, viscosity, and chemical kinetics. As a result, it is shown that flame interaction with the walls leads to the oscillating regime of burning. The oscillations involve variations of the curved flame shape and the velocity of flame propagation. The oscillation parameters depend on the characteristic tube width, which controls the Reynolds number of the flow. In narrow tubes the oscillations are rather weak, while in wider tubes they become stronger with well-pronounced nonlinear effects. The period of oscillations increases for wider tubes, while the average flame length scaled by the tube diameter decreases only slightly with increasing tube width. The average flame length calculated in the present work is in agreement with that obtained in the experiments. Numerical results reduce the gap between the theory of turbulent flames and the experiments on turbulent combustion in tubes. (author)

  16. Experimental validation of error in temperature measurements in thin walled ductile iron castings

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2007-01-01

    An experimental analysis has been performed to validate the measurement error of cooling curves measured in thin walled ductile cast iron. Specially designed thermocouples with Ø0.2 mm thermocouple wire in Ø1.6 mm ceramic tube was used for the experiments. Temperatures were measured in plates...

  17. Distortional Modes of Thin-Walled Beams

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Andreassen, Michael Joachim

    2009-01-01

    The classic thin-walled beam theory for open and closed cross-sections can be generalized by including distortional displacement modes. The introduction of additional displacement modes leads to coupled differential equations, which seems to have prohibited the use of exact shape functions...... in the modelling of coupled torsion and distortion. However, if the distortional displacement modes are chosen as those which decouple the differential equations as in non proportionally damped modal dynamic analysis then it may be possible to use exact shape functions and perform analysis on a reduced problem....... In the recently developed generalized beam theory (GBT) the natural distortional displacement modes are determined on the basis of a quadratic eigenvalue problem. However, as in linear modal dynamic analysis of proportionally damped structures this problem has been solved approximately using linear eigenvalue...

  18. Force-free thin flux tubes: Basic equations and stability

    International Nuclear Information System (INIS)

    Zhugzhda, Y.D.

    1996-01-01

    The thin flux tube approximation is considered for a straight, symmetrical, force-free, rigidly rotating flux tube. The derived set of equations describes tube, body sausage, and Alfveacute charn wave modes and is valid for any values of Β. The linear waves and instabilities of force-free flux tubes are considered. The comparison of approximate and exact solutions for an untwisted, nonrotating flux tube is performed. It is shown that the approximate and exact dispersion equations coincides, except the 20% discrepancy of sausage frequencies. An effective cross section is proposed to introduce the removal of this discrepancy. It makes the derived approximation correct for the force-free thin flux tube dynamics, except the detailed structure of radial eigenfunction. The dispersion of Alfveacute charn torsional waves in a force-free tubes appears. The valve effect of one directional propagation of waves in rotating twisted tube is revealed. The current and rotational sausage instabilities of a force-free, thin flux tube are considered. copyright 1996 American Institute of Physics

  19. Multi-wall nanotube as tube dislocation

    International Nuclear Information System (INIS)

    Berredo-Peixoto, G. de; Shapiro, I.L.; Katanaev, M.O.; Konstantinova, E.

    2011-01-01

    Full text: The recently invented cylindrical geometric space defect is applied to the electron behaviour in the system which can be regarded as a simplified model of a double-wall nanotube. By solving the Schrodinger equation in the region of space with cylindrical geometric defect we explore the influence of such geometric defect on the energy gap and charge distribution. The effect is qualitatively similar to the one obtained earlier by means of traditional simulation methods. In general, the geometric approach can not compete with the known methods of theoretical study of the nanostructures, such as molecular dynamics. However it may be useful for better qualitative understanding of the electronic properties of the nanosystems. It is obvious that the method based on geometric defects can not compete with the standard approaches based on molecular dynamics. The reason is that the geometric defects method can not take into account full details of the structure of the compound and is, in some sense, too general. At the same time this method may become much more interesting if one develops it further and, in particular, learns how to deal with more sophisticated versions of geometric defects. In particular, it looks possible to take into account the chirality of the nanotube and, also, include the external magnetic field. We expect to consider these issues elsewhere. (author)

  20. Impact effects in thin-walled structures

    International Nuclear Information System (INIS)

    Zukas, J.A.; Gaskill, B.

    1996-01-01

    A key parameter in the design of protective structures is the critical impact velocity, also known as the ballistic limit. This is the velocity below which a striker will fail to penetrate a barrier or some protective device. For strikers with regular shapes, such as cylinders (long and short), spheres and cones, analytical and empirical formulations for the determination of a ballistic limit exist at impact velocities ranging from 250 m/s to 6 km/s or higher. For non-standard shapes, two- and three-dimensional wave propagation codes (hydrocodes) can be valuable adjuncts to experiments in ballistic limit determinations. This is illustrated with the help of the ZeuS code in determining the ballistic limit of a short, tubular projectile striking a thin aluminum barrier and contrasting it to the value of the ballistic limit of a spherical projectile of equal mass against the same target. Several interesting features of the debris cloud generated by a tubular projectile striking a Whipple shield at hypervelocity are also pointed out. The paper concludes with a consideration of hydrodynamic ram effects in fluid-filled thin-walled structures. Where possible, comparisons are made of computed results with experimental data

  1. NPPs Secondary Circuit Piping Wall-Thinning Management in China

    International Nuclear Information System (INIS)

    Zhong Zhimin; Li Jinsong; Zheng Hui

    2012-01-01

    Since 1980s, secondary circuit piping wall-thinning incidents happened in nuclear power plants (NPPs) worldwide. Particularly Surry 2 and Mihama 3 accidents resulted from flow-accelerated corrosion (FAC), unplanned outage, huge fatalities and economic loss pushed whole industry to pay more attention on the wall-thinning problem.

  2. Failure Behavior of Elbows with Local Wall Thinning

    Science.gov (United States)

    Lee, Sung-Ho; Lee, Jeong-Keun; Park, Jai-Hak

    Wall thinning defect due to corrosion is one of major aging phenomena in carbon steel pipes in most plant industries, and it results in reducing load carrying capacity of the piping components. A failure test system was set up for real scale elbows containing various simulated wall thinning defects, and monotonic in-plane bending tests were performed under internal pressure to find out the failure behavior of them. The failure behavior of wall-thinned elbows was characterized by the circumferential angle of thinned region and the loading conditions to the piping system.

  3. Development of the double-wall-tube steam generator. Evaluation of inner tube leak detection system

    International Nuclear Information System (INIS)

    Teraoku, Takuji; Kisohara, Naoyuki

    1995-01-01

    A double-wall-tube steam generator (DWT-SG) is considered to have possibility of eliminating a secondary heat transport system to realize a reliable and simplified FBR plant. Thus, basic tests for inner/outer tube leak detection and prototypical leak tests by use of the 1MWt DWT-SG model have been performed to evaluate the feasibility of DWT-SG. Their results demonstrated that the inner leak detection system can definitely detect a steam leak from an inner tube flaw. Analyses of the inner tube leak and detection behavior obtained in the 1MWt DWT-SG test enabled to estimate the performance of the inner tube detection system of the commercial DWT-SG system. (author)

  4. Development of pipe wall thinning prediction software 'FALSET'

    International Nuclear Information System (INIS)

    Yoneda, Kimitoshi; Morita, Ryo; Inada, Fumio; Fujiwara, Kazutoshi

    2012-01-01

    Pipe wall thinning in power plants has been managed for maintaining plant integrity and safety with great importance. The target thinning phenomena are Flow Accelerated Corrosion (FAC) and Liquid Droplet Impingement Erosion (LDI). At present, the management is based on thinning rate and residual lifetime evaluation using pipe wall thickness measurement results. For the future, more safety and improvement in the management is required, and in this sense, prediction method of wall thinning is willing to be introduced. Therefore, prediction model of FAC and LDI have been constructed in CRIEPI, and to utilize these models to actual plant piping management easily, prediction software 'FALSET' is developed. FALSET has equipped with essential function for pipe wall thinning management in power plants, as follows; (1) Information and condition input of plant piping system and its component, (2) Wall thinning rate evaluation with CRIEPI's FAC/LDI prediction model, (3) Loading of wall thickness measurement data files and graphics of data trend, (4) Residual lifetime evaluation considering both measured and predicted thinning rate, (5) Statistical process and graphics of thinning rate and residual lifetime for multi-piping systems. With further verification and improvement of each function, there will be a perspective for this FALSET to be utilized as a management tool in power plants. (author)

  5. Geometric Relations for CYLEX Test Tube-Wall Motion

    Science.gov (United States)

    Hill, Larry

    2015-06-01

    The CYLinder EXpansion (CYLEX) test is a (precision, instrumented, high-purity annealed copper) pipe bomb. Its essential measured quantities are detonation speed and tube-wall motion. Its main purpose is to calibrate detonation product equations of state (EOS) by measuring how product fluid pushes metal. In its full complexity, CYLEX is an integral test, for which EOS calibration requires the entire system to be computationally modeled and compared to salient data. Stripped to its essence, CYLEX is a non-integral test for which one may perform the inverse problem, to infer the EOS directly from data. CYLEX analysis can be simplified by the fact that the test constituents achieve a steady traveling wave structure; this allows derivation of several useful geometric relationships regarding tube wall motion. The first such treatment was by G.I. Taylor. Although his analysis was limited to small wall deflection angles, he asserted that the results remain valid for arbitrary ones. I confirm this attribute and present additional useful relationships. In the past decade, CYLEX wall-motion instrumentation has migrated almost entirely from streak camera to PDV, yet discrepancies remain between the two methods. I further present geometric relationships that shed light on this issue. Work supported by the U.S. DOE.

  6. Shock-tube study of fusion plasma-wall interactions

    International Nuclear Information System (INIS)

    Gross, R.A.; Tien, J.K.; Jensen, B.; Panayotou, N.F.; Feinberg, B.

    1977-01-01

    Theoretical and experimental studies have been made of phenomena which occur when a hot (T 1 approximately equal to 6 x 10 6 0 K), dense (n approximately equal to 10 16 cm -3 ), deuterium plasma containing a transverse magnetic field is brought into sudden contact with a cold metal wall. These studies are motivated by the need to understand plasma and metallurgical conditions at the first-wall of a fusion reactor. Experiments were carried out in the Columbia high energy electromagnetic shock tube. Computational simulation was used to investigate the detailed physics of the fusion plasma boundary layer which develops at the wall. The rate of energy transfer from the plasma to the wall was calculated and conditions under which surface melting occurs are estimated. Experimental measurements of plasma-wall heat transfer rates up to 3 x 10 5 watts/cm 2 were obtained and agreement with computed values are good. Fusion reactor first-wall materials have been exposed to 6.0 x 10 21 eV cm -2 (1,000 shots) of deuterium plasma bombardment. Scanning electron micrograph photographs show preferential erosion at grain boundaries, formation of deuterium surface blisters, and evidence of local surface melting. Some cracking is observed along grain boundaries, and a decrease in tensile ductiity is measured

  7. Thin-wall approximation in vacuum decay: A lemma

    Science.gov (United States)

    Brown, Adam R.

    2018-05-01

    The "thin-wall approximation" gives a simple estimate of the decay rate of an unstable quantum field. Unfortunately, the approximation is uncontrolled. In this paper I show that there are actually two different thin-wall approximations and that they bracket the true decay rate: I prove that one is an upper bound and the other a lower bound. In the thin-wall limit, the two approximations converge. In the presence of gravity, a generalization of this lemma provides a simple sufficient condition for nonperturbative vacuum instability.

  8. Humidity Sensor Based on Multi-Walled Carbon Nanotube Thin Films

    International Nuclear Information System (INIS)

    Cao, C.L.; Hu, C.G.; Fang, L.; Wang, S.X.; Cao, C.L.; Tian, Y.S.; Pan, C.Y.

    2009-01-01

    The properties of the humidity sensors made of chemically treated and untreated multi-walled carbon nano tube (MWCNT) thin films are investigated systematically. It shows that both the chemically treated and untreated MWCNT thin films demonstrate humidity sensitive properties, but the former have stronger sensitivity than the latter. In the range of 11%-98% relative humidity (RH), the resistances of the chemically treated and untreated MWCNT humidity sensors increase 120% and 28%, respectively. Moreover, the treated humidity sensors showed higher sensitivity and better stability. In addition, the response and recover properties, and stabilization of the humidity sensors are measured, and the humidity sensitive mechanisms of the sensors are analyzed. The humidity sensitivity of carbon nano tube thin films indicates it promise as a kind of humidity sensitive material

  9. Plastic collapse behavior for thin tube with two parallel cracks

    International Nuclear Information System (INIS)

    Moon, Seong In; Chang, Yoon Suk; Kim, Young Jin; Lee, Jin Ho; Song, Myung Ho; Choi, Young Hwan; Kim, Joung Soo

    2004-01-01

    The current plugging criterion is known to be too conservative for some locations and types of defects. Many defects detected during in-service inspection take on the form of multiple cracks at the top of tube sheet but there is no reliable plugging criterion for the steam generator tubes with multiple cracks. Most of the previous studies on multiple cracks are confined to elastic analyses and only few studies have been done on the steam generator tubes failed by plastic collapse. Therefore, it is necessary to develop models which can be used to estimate the failure behavior of steam generator tubes with multiple cracks. The objective of this study is to verify the applicability of the optimum local failure prediction models proposed in the previous study. For this, plastic collapse tests are performed with the tube specimens containing two parallel through-wall cracks. The plastic collapse load of the steam generator tubes containing two parallel through-wall cracks are also estimated by using the proposed optimum global failure model and the applicability is investigated by comparing the estimated results with the experimental results. Also, the interaction effect between two cracks was evaluated to explain the plastic collapse behavior

  10. Thin-walled reinforcement lattice structure for hollow CMC buckets

    Science.gov (United States)

    de Diego, Peter

    2017-06-27

    A hollow ceramic matrix composite (CMC) turbine bucket with an internal reinforcement lattice structure has improved vibration properties and stiffness. The lattice structure is formed of thin-walled plies made of CMC. The wall structures are arranged and located according to high stress areas within the hollow bucket. After the melt infiltration process, the mandrels melt away, leaving the wall structure to become the internal lattice reinforcement structure of the bucket.

  11. Phenomenology of the domain walls in thin ferromagnetic films

    International Nuclear Information System (INIS)

    Adam, G.

    1978-01-01

    The basic concepts and the main theoretical methods developed in the study of the domain walls in thin ferromagnetic films are given in this review. First, an insight into the origins and the classification criteria of the conceptually different wall structures is obtained by elementary considerations which are mainly based on the experimentally available data. Then, the more subtle aspect of the wall models dimensionality in soft ferromagnetic films is discussed. Finally, the various theoretical calculation methods of the wall parameters are summarized. (author)

  12. Control and optimization of solute transport in a thin porous tube

    KAUST Repository

    Griffiths, I. M.

    2013-03-01

    Predicting the distribution of solutes or particles in flows within porous-walled tubes is essential to inform the design of devices that rely on cross-flow filtration, such as those used in water purification, irrigation devices, field-flow fractionation, and hollow-fibre bioreactors for tissue-engineering applications. Motivated by these applications, a radially averaged model for fluid and solute transport in a tube with thin porous walls is derived by developing the classical ideas of Taylor dispersion. The model includes solute diffusion and advection via both radial and axial flow components, and the advection, diffusion, and uptake coefficients in the averaged equation are explicitly derived. The effect of wall permeability, slip, and pressure differentials upon the dispersive solute behaviour are investigated. The model is used to explore the control of solute transport across the membrane walls via the membrane permeability, and a parametric expression for the permeability required to generate a given solute distribution is derived. The theory is applied to the specific example of a hollow-fibre membrane bioreactor, where a uniform delivery of nutrient across the membrane walls to the extra-capillary space is required to promote spatially uniform cell growth. © 2013 American Institute of Physics.

  13. Fiber pigtailed thin wall capillary coupler for excitation of microsphere WGM resonator.

    Science.gov (United States)

    Wang, Hanzheng; Lan, Xinwei; Huang, Jie; Yuan, Lei; Kim, Cheol-Woon; Xiao, Hai

    2013-07-01

    In this paper, we demonstrate a fiber pigtailed thin wall capillary coupler for excitation of Whispering Gallery Modes (WGMs) of microsphere resonators. The coupler is made by fusion-splicing an optical fiber with a capillary tube and consequently etching the capillary wall to a thickness of a few microns. Light is coupled through the peripheral contact between inserted microsphere and the etched capillary wall. The coupling efficiency as a function of the wall thickness was studied experimentally. WGM resonance with a Q-factor of 1.14 × 10(4) was observed using a borosilicate glass microsphere with a diameter of 71 μm. The coupler operates in the reflection mode and provides a robust mechanical support to the microsphere resonator. It is expected that the new coupler may find broad applications in sensors, optical filters and lasers.

  14. Multi-walled carbon nano-tubes for energy storage and production applications

    International Nuclear Information System (INIS)

    Andrews, R.; Jacques, D.; Likpa, S.; Qian, D.; Rantell, T.; Anthony, J.

    2005-01-01

    Full text of publication follows: Since their discovery, carbon nano-tubes have been proposed as candidate materials for a broad range of applications, including high strength composites, molecular electronics, and energy storage. In many cases, nano-tubes have been proposed to replace traditional carbon materials, such as activated carbons in energy storage devices. In other cases, novel applications have been proposed, such as the use of carbon nano-tube arrays in photovoltaic devices. The use of multi-walled carbon nano-tubes in energy storage devices has generated great interest due to their high inherent conductivity, layered structure, and high surface area per volume compared to traditional graphitic materials. However as produced nano-tubes do not possess ideal properties, and exhibit only modest charge storage. We have explored the charge storage abilities of nano-tubes with varying morphologies (fullerenic versus stacked cones), nano-tubes containing N or B dopants, as well as various post-treatments of the nano-tubes. The use of nano-tubes in charge storage devices will be described, as well as modification of the nano-tube surfaces or morphology to improve this performance. The synthesis of nano-tubes with several differing hetero-atom dopants will also be described, as well as the effect of heat treatment on these structures. One of the most significant problems in organic photovoltaics is the typically low charge-carrier mobility in organic thin films which, coupled with short exciton diffusion lengths, means that photo-generated charge-carrier pairs are more likely to re-combine than reach an electrode to generate current. Two organic systems with high charge-carrier mobilities are carbon nano-tubes (here, MWNTs) and acene-based organic semiconductors. We believe that blended devices based on MWNTs and organic semiconductors could lead to the next class of efficient, flexible and inexpensive organic photovoltaic systems. We have developed methods to

  15. Investigation of the Geometry of Metal Tube Walls after Necking in Uniaxial Tension

    Directory of Open Access Journals (Sweden)

    Chong Li

    2017-03-01

    Full Text Available Abstract: In order to characterize the deformation and true stress–strain relation of metal tubes, the geometry of tube walls after necking in uniaxial tension need to be determined. The paper investigated the necking process of metal tube. A large number of tensile tests and finite element analysis of 1Cr18Ni9Ti tubes with different sizes were conducted. It was found that the geometry of outer tube wall in the necking region can be described using a logistic regression model. The final geometry of the tube is determined by original tube diameter and wall thickness. The offset of tube walls are affected by two competing factors: volume constancy and necking. The offset distances of outer and inner walls are mainly affected by original wall thickness. The length of the necking zone is more influenced by original tube diameter. Tube elongation at fracture increases slightly as tube diameter gets larger, while the wall thickness has almost no impact on the elongation.

  16. Evaluation of plugging criteria on steam generator tubes and coalescence model of collinear axial through-wall cracks

    International Nuclear Information System (INIS)

    Lee, Jin Ho; Park, Youn Won; Song, Myung Ho; Kim, Young Jin; Moon, Seong In

    2000-01-01

    In a nuclear power plant, steam generator tubes cover a major portion of the primary pressure-retaining boundary. Thus very conservative approaches have been taken in the light of steam generator tube integrity. According to the present criteria, tubes wall-thinned in excess 40% should be plugged whatever causes are. However, many analytical and experimental results have shown that no safety problems exist even with thickness reductions greater than 40%. The present criterion was developed about twenty years ago when wear and pitting were dominant causes for steam generator tube degradation. And it is based on tubes with single cracks regardless of the fact that the appearance of multiple cracks is more common in general. The objective of this study is to review the conservatism of the present plugging criteria of steam generator tubes and to propose a new coalescence model for two adjacent through-wall cracks existing in steam generator tubes. Using the existing failure models and experimental results, we reviewed the conservatism of the present plugging criteria. In order to verify the usefulness of the proposed new coalescence model, we performed finite element analysis and some parametric studies. Then, we developed a coalescence evaluation diagram

  17. Conservatism of present plugging criteria on steam generator tubes and coalescence model of collinear through-wall axial cracks

    International Nuclear Information System (INIS)

    Lee, Jin Ho; Park, Youn Won; Song, Myung Ho; Kim, Young Jin; Moon, Seong In

    1999-01-01

    The steam generator tubing covers a major portion of the primary pressure-retaining boundary, so that very conservative approaches were taken in the light of steam generator tube integrity. According to the present criteria, tubes wall-thinned in excess of 40% should be plugged whatever the cause was. However, it is reported that there is no safety problem even with thickness reductions greater than 40%. Recently, the plant specific plugging criteria are introduced in many countries by demonstrating that the cracked tube has a sufficient safety margin. One of the drawbacks of such criteria, even though not yet codified, is that it is developed based on tubes with single cracks regardless of the fact that the appearance of multiple cracks is general. Their failure analyses have been, therefore, carried out using an idealized single crack to reduce complexity till now. The objective of this paper is to review the conservatism of the present plugging criteria of steam generator tubes and to propose a new coalescence criterion for twin through-wall cracks existing in steam generator tubes. Using the existing failure models and experimental results, we review the conservatism of the present plugging criteria. In order to verify the usefulness of the proposed new coalescence criterion, we perform finite element analysis

  18. Linear motion feed through with thin wall rubber sealing element

    Science.gov (United States)

    Mikhailov, V. P.; Deulin, E. A.

    2017-07-01

    The patented linear motion feedthrough is based on elastic thin rubber walls usage being reinforced with analeptic string fixed in the middle part of the walls. The pneumatic or hydro actuators create linear movement of stock. The length of this movement is two times more the rubber wall length. This flexible wall is a sealing element of feedthrough. The main advantage of device is negligible resistance force that is less then mentioned one in sealing bellows that leads to positioning error decreasing. Nevertheless, the thin wall rubber sealing element (TRE) of the feedthrough is the main unreliable element that was the reason of this element longevity research. The theory and experimental results help to create equation for TRE longevity calculation under vacuum or extra high pressure difference action. The equation was used for TRE longevity determination for hydraulic or vacuum equipment realization also as it helps for gas flow being leaking through the cracks in thin walls of rubber sealing element of linear motion feedthrough calculation.

  19. 75 FR 82070 - Light-Walled Rectangular Pipe and Tube From China, Korea, and Mexico

    Science.gov (United States)

    2010-12-29

    ...-Walled Rectangular Pipe and Tube From China, Korea, and Mexico AGENCY: United States International Trade... from China, Korea, and Mexico that were found to be sold at less than fair value. Nacional de Acero S... panel proceeding in Light-Walled Rectangular Pipe and Tube from Mexico, USA-MEX-1904-04, to file...

  20. Manufacturing of thin walled near net shape iron castings

    DEFF Research Database (Denmark)

    Larsen, Per Leif

    2003-01-01

    The demand for near net shape thin walled iron castings is growing. This has several reasons, the main one is the need for lowering the fuel consumption of cars; the easiest way to do that is to lower the weight of the cars. The best way to do this was for a period of time believed...

  1. Buckling of thin-walled beams under concentrated transverse loading

    NARCIS (Netherlands)

    Menken, C.M.; Erp, van G.M.; Krupta, V.; Drdacky, M.

    1991-01-01

    The transversely loaded thin-walled beam under a non-uniform bending moment forms an example of the detrimental influence that a local effect may have on the overall behaviour. The local effect is the plate buckling in the region of maximum bending moment. The overall behaviour is the

  2. Stabilization of thin shell modes by a rotating secondary wall

    International Nuclear Information System (INIS)

    Gimblett, C.G.

    1989-01-01

    A simple model is developed to investigate if and under what circumstances the thin shell instabilities of a Reverse Field Pinch can be stabilized by a rotating secondary wall. The principles may be applicable to reactor designs that utilize a flowing liquid blanket (author)

  3. Vibration improved the fluidity of aluminum alloys in thin wall ...

    African Journals Online (AJOL)

    Misrun is a term used to describe the incomplete filling of the mould cavity. It is a major defect in the investment casting process when used to produce turbine blades, impellers and impulse blades for turbo pumps which have complex profiles, thin walls and sharp edges. From the casting engineering point of view, poor ...

  4. Impact of plasma tube wall thickness on power coupling in ICP sources

    International Nuclear Information System (INIS)

    Nawaz, Anuscheh; Herdrich, Georg

    2009-01-01

    The inductively heated plasma source at the Institute of Space Systems was investigated with respect to the wall thickness of the plasma tube using an air plasma. For this, the wall thickness of the quartz tube was reduced in steps from 2.5 to 1.25 mm. The significance of reducing the wall thickness was analyzed with respect to both the maximum allowable tube cooling power and the coupling efficiency. While the former results from thermal stresses in the tube's wall, the latter results from a minimization of magnetic field losses near the coil turns of the inductively coupled plasma (ICP) source. Analysis of the thermal stress could be validated by experimental data, i.e. the measurement of the tube cooling power when the respective tube structure failed. The coupling efficiency could be assessed qualitatively by simplified models, and the experimental data recorded show that coupling was improved far more than predicted.

  5. Analysis of prestressed double-wall tubing for LMFBR steam generators

    International Nuclear Information System (INIS)

    Uber, C.F.; Langford, P.J.

    1981-01-01

    A radial interface pressure is provided between the inner and outer tubes of each double-wall tube in a steam generator design now being developed for commercial breeder reactor plants. This paper describes a finite element analysis of the manufacturing technique used to prestress the double-wall tube. The analytical predictions are compared with experimental measurements of the residual interface pressure. Resulting residual stress states are used as the starting point for operating condition analyses. 9 refs

  6. Current Status on the Development of a Double Wall Tube Steam Generator

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ho Yun; Choi, Byoung Hae; Kim, Jong Man; Kim, Byung Ho

    2007-12-15

    A fast reactor, which uses sodium as a coolant, has a lot of merits as a next generation nuclear reactor. However, the possibility of a sodium-water reaction occurrence hinders the commercialization of this reactor. As one way to improve the reliability of a steam generator, a double-wall tube steam generator is being developed in GEN-4 program. In this report, the current state of the technical developments for a double-wall tube steam generator are reviewed and a future plan for the development of a double-wall tube steam generator is established. The current focuses of this research are an improvement of the heat transfer capability for a double-wall tube and the development of a proper leak detection method for the failure of a double-wall tube during a reactor operation. The ideal goal is an on-line leak detection of a double wall tube to prevent the sodium-water reaction. However, such a method is not developed as yet. An alternative method is being used to improve the reliability of a steam generator by performing a non-destructive test of a double wall tube during the refueling period of a reactor. In this method a straight double wall tube is employed to perform this test easily, but has a difficulty regarding an absorption of a thermal expansion of the used materials. If an on-line leak detection method is developed, the demerits of a straight double-wall tube are avoided by using a helical type double-wall tube, and the probability of a sodium-water reaction can be reduced to a level less than the design-based accident.

  7. Durability of thin-walled concrete structures

    International Nuclear Information System (INIS)

    Salomon, M.; Gallias, J.L.

    1991-01-01

    The aim of the present document is to draw up a survey of knowledge of the problems of ageing of reinforced concrete shell structure atmospheric coolers. The exposure conditions are particularly favourable to the induction and development of degradation which, because of the thinness of the reinforced concrete can compromise the stability and the durability of coolers. The study will be axed on the link between the specific characteristics of coolers from the point of view of operation, design and environment, also the durability of reinforced concrete. The set of factors exerting their influence on the reinforced concrete of the shell structure (condensates, rain water, temperature and humidity gradients, dynamic loads, weathering, etc.) is particularly complex. The principal degradation reactions involved are classified according to the chemical and physical action on concrete and on the reinforcement. Particular emphasis is placed on the analysis of degradation processes and the influence of the characteristics of the materials and of the medium. The aim is to determine the mechanisms which present the greatest risk for coolers. The interaction between the degradation to concrete and the change in mechanical characteristics is also studied [fr

  8. Development of a helical-coil double wall tube steam generator for 4S reactor

    International Nuclear Information System (INIS)

    Kitajima, Yuko; Maruyama, Shigeki; Jimbo, Noboru; Hino, Takehisa; Sato, Katsuhiko

    2011-01-01

    The 4S, Super-Safe Small and Simple, is a small-sized sodium-cooled fast reactor. A fast reactor usually uses sodium as a coolant to transfer heat from core to turbine/generator system. The heat of the intermediate heat transport system and that of the water stream systems are exchanged by the steam generator (SG) tubes. If the tube failure occurs, a sodium/water reaction could be occurred. To prevent the reaction and enhance safety, a helical-coil-type double wall tube with wire mesh interlayer and continuous monitoring systems of tube failure are applied to the SG of the 4S. The development and general features of this type double wall tube were described in Ref. 1) and Ref. 2). Those paper summarized following results; The tubes studied in these references were straight type. To establish this SG, development of manufacturing method of helical-coil-type double wall tube and validation of the tube failure monitoring system are needed. In this study, three demonstration tests have been performed; welding test of the double wall tube to manufacture the tubes with 70-80m length, assembling test of the helical-coil tube, and confirmation test of the tube processing system using the fabricated helical-coil tubes. As a result, following technologies have been successfully established. (1) Development of the welding techniques for manufacturing of the helical-coil-type double wall tube with wire mesh interlayer. (2) The confirmation test for manufacturing the helical coil tube of the SG. (author)

  9. The Dynamic Similitude Design Method of Thin Walled Structures and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Zhong Luo

    2016-01-01

    Full Text Available For the applicability of dynamic similitude models of thin walled structures, such as engine blades, turbine discs, and cylindrical shells, the dynamic similitude design of typical thin walled structures is investigated. The governing equation of typical thin walled structures is firstly unified, which guides to establishing dynamic scaling laws of typical thin walled structures. Based on the governing equation, geometrically complete scaling law of the typical thin walled structure is derived. In order to determine accurate distorted scaling laws of typical thin walled structures, three principles are proposed and theoretically proved by combining the sensitivity analysis and governing equation. Taking the thin walled annular plate as an example, geometrically complete and distorted scaling laws can be obtained based on the principles of determining dynamic scaling laws. Furthermore, the previous five orders’ accurate distorted scaling laws of thin walled annular plates are presented and numerically validated. Finally, the effectiveness of the similitude design method is validated by experimental annular plates.

  10. Creep collapse of thick-walled heat transfer tube subjected to external pressure at high temperature

    International Nuclear Information System (INIS)

    Ioka, Ikuo; Kaji, Yoshiyuki; Terunuma, Isao; Nekoya, Shin-ichi; Miyamoto, Yoshiaki

    1994-09-01

    A series of creep collapse tests of thick-walled heat transfer tube were examined experimentally and analytically to confirm an analytical method for creep deformation behavior of a heat transfer tube of an intermediate heat exchanger (IHX) at a depressurization accident of secondary cooling system of HTTR (High Temperature Engineering Test Reactor). The tests were carried out using thick-walled heat transfer tubes made of Hastelloy XR at 950degC in helium gas environment. The predictions of creep collapse time obtained by a general purpose FEM-code ABAQUS were in good agreement with the experimental results. A lot of cracks were observed on the outer surface of the test tubes after the creep collapse. However, the cracks did not pass through the tube wall and, therefore, the leak tightness was maintained regardless of a collapse deformation for all tubes tested. (author)

  11. Gamma radiation inside closed volumes with thin irradiating walls

    International Nuclear Information System (INIS)

    Karpov, V.I.

    1978-01-01

    The dose rate of gamma radiation inside a parallelepiped with thin radiating walls was calculated. The calculation was based on determining the dose rate from a rectangular plate and subsequently summing the dose rates from all the parallelepiped walls. The dose rate from the rectangular plate was calculated by reducing it to an equivalent plate of infinite length and certain fixed width. When the radiators had constant surface density, the dose rate in the geometric centre of volumes having the form of a parallelepiped was shown to have the least value in the case when the parallelepiped degenerates to a cube

  12. Reliability of double-wall-tube steam generator for FBR considering water leak accident frequency

    International Nuclear Information System (INIS)

    Ueda, Nobuyuki; Kinoshita, Izumi; Nishi, Yoshihisa

    2000-01-01

    For early realization, a fast breeder reactor (FBR) is required to reduce construction cost. A reactor concept in which the intermediate heat transport system is eliminated by introducing a double-wall-tube steam generator is one convincing approach. The reliability of the double-wall-tube SG in a water leak accident (sodium-water reaction accident) due to tube failure is strongly related to the mitigating system design. The safety design of the double-wall-tube SG approach is investigated to limit the accident occurrence below 10 -7 (1/ry. A tube-to-tube weld is excluded from the reference design, because the welding process is too difficult and complicated to effectively prevent adhesion of the double-wall-tube. The reliability of the tube-to-tube plate was evaluated at 10 -10 (l/hr) for an inner tube and 10 -9 (l/hr) for an outer with reference to the failure experience of previous SGs. The failure must be detected within 30 to 60 minutes. (author)

  13. 78 FR 42546 - Light-Walled Rectangular Pipe and Tube From China, Korea, Mexico, and Turkey: Notice of...

    Science.gov (United States)

    2013-07-16

    ...-Walled Rectangular Pipe and Tube From China, Korea, Mexico, and Turkey: Notice of Commission... countervailing duty order on light-walled rectangular pipe and tube from China and the antidumping duty orders on light-walled rectangular pipe and tube from China, Korea, Mexico, and Turkey would be likely to lead to...

  14. 78 FR 74161 - Light-Walled Rectangular Pipe and Tube From China, Korea, Mexico, and Turkey; Scheduling of Full...

    Science.gov (United States)

    2013-12-10

    ...-Walled Rectangular Pipe and Tube From China, Korea, Mexico, and Turkey; Scheduling of Full Five-Year... the Antidumping Duty Orders on Light-Walled Rectangular Pipe and Tube From China, Korea, Mexico, and... on light- walled rectangular pipe and tube from China, Korea, Mexico, and Turkey would be likely to...

  15. Location and optimization analysis of capillary tube network embedded in active tuning building wall

    International Nuclear Information System (INIS)

    Niu, Fuxin; Yu, Yuebin

    2016-01-01

    In this study, a building wall with a thermal tuning function is further investigated. This design turns the building wall from a passive thermal system to an active system. A capillary tube network is installed inside the wall to manipulate the thermodynamics and realize more flexibility and potentials of the wall. This novel building wall structure performs efficiently in terms of building load reduction and supplementary heating and cooling, and the structure is convenient for applying low grade or natural energy with a wider temperature range. The capillary tube network's location inside the wall greatly impacts the thermal and energy performance of the building wall. The effects of three locations including external, middle and internal side are analyzed. The results indicate that the internal wall surface temperature can be neutralized from the ambient environment when the embedded tubes are fed with thermal water. The wall can work with a wide range of water temperature and the optimal location of the tube network is relatively constant in different modes. Power benefit with the wall changes from 2 W to 39 W when the outdoor air temperature changes, higher in summer than in winter. - Highlights: • A building wall with a tuning function is proposed using a capillary pipe network. • Low-grade thermal water can be used to actively manipulate the thermal mass. • Location of the capillary network is investigated to maximize the performance. • The innovation can potentially lower down the grade of energy use in buildings.

  16. Distortional Mechanics of Thin-Walled Structural Elements

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim

    In several industries such as civil, mechanical, and aerospace, thin-walled structures are often used due to the high strength and effective use of the materials. Because of the increased consumption there has been increasing focus on optimizing and more detailed calculations. However, finely...... number of degrees of freedom. This means that the classical Vlasov thin-walled beam theory for open and closed cross sections is generalized as part of a semi-discretization process by including distortional displacement fields. A novel finite-element-based displacement approach is used in combination...... by discretization of the cross section are now solved analytically and the formulation is valid without special attention and approximation also for closed single or multi-cell cross sections. Furthermore, the found eigenvalues have clear mechanical meaning, since they represent the attenuation of the distortional...

  17. Studying energy absorption in tapered thick walled tubes

    Directory of Open Access Journals (Sweden)

    P. Hosseini Tehrani

    Full Text Available In many engineering structures different energy absorption systems may be used to improve crashworthiness capability of the system and to control damages that may occur in a system during an accident. Therefore, extensive research has been done on the energy-absorbing cells. In this paper, energy absorption in tapered thick walled tubes has been investigated. As a practical case, studies have been focused on the crush element of Siemens ER24PC locomotive. To investigate performance of this part at collision time, it has been modeled in Abaqus software and its collision characteristics have been evaluated. Considering that the crash element is folded at time of collision, an analytical approach has been presented for calculation of instantaneous folding force under axial load. Basis of this method is definition and analysis of main folding mechanism and calculation of average folding force. This method has been used for validation of the results of numerical solution. Since sheet thickness of the crash element is high and may be ruptured at time of collision, some damage models have been used for numerical simulations. One of the three damage models used in this paper is available in the software and coding has been done for two other damage models and desirable damage model has been specified by comparing results of numerical solution with results of laboratory test. In addition, authenticity of the desirable damage model has been studied through ECE R 66 standard. To improve crashworthiness characteristic some attempts, such as use of metal foam and creation of trigger in suitable situations to reduce maximum force resulting from collision, have been performed. Finally though different simulation optimal crush element has been introduced and its performance and efficiency have been evaluated.

  18. Bioactive surface modifications on inner walls of poly-tetra-fluoro-ethylene tubes using dielectric barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Ki [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Heat Treatment and Surface Engineering R and D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Park, Daewon; Kim, Hoonbae [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Hyerim; Park, Heonyong [Department of Molecular Biology, Dankook University, Yongin 448-701 (Korea, Republic of); Kim, Hong Ja [Department of Internal Medicine, Dankook University, Cheonan 330-714 (Korea, Republic of); Jung, Donggeun, E-mail: djung@skku.ac.kr [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-03-01

    Graphical abstract: - Highlights: • The surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts. • Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment using micro plasma discharge. - Abstract: Bioactive surface modification can be used in a variety of medical polymeric materials in the fields of biochips and biosensors, artificial membranes, and vascular grafts. In this study, the surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts, which are made of biocompatible material for the human body in the medical field. Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment on the PFTE surface using micro plasma discharge. Micro plasma was generated by a medium-frequency alternating current high-voltage generator. The preliminary modification of PTFE was conducted by a plasma of hydrogen and argon gases. The hydrocarbon thin film was deposited on modified PTFE with a mixture of acetylene and argon gases. The reactive plasma treatment using oxygen plasma was done to give biocompatible functionality to the inner wall surface. The hydrophobic surface of bare PTFE is made hydrophilic by the reactive plasma treatment due to the formation of carbonyl groups on the surface. The reactive treatment could lead to improved attachment of smooth muscle cells (SMCs) on the modified PTFE tubing. Fourier transform infrared absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle measurement were used for the analysis of the surface modification. The SMC-attached PTFE tube developed will be applicable to in vitro human vasculature

  19. Bioactive surface modifications on inner walls of poly-tetra-fluoro-ethylene tubes using dielectric barrier discharge

    International Nuclear Information System (INIS)

    Cho, Yong Ki; Park, Daewon; Kim, Hoonbae; Lee, Hyerim; Park, Heonyong; Kim, Hong Ja; Jung, Donggeun

    2014-01-01

    Graphical abstract: - Highlights: • The surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts. • Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment using micro plasma discharge. - Abstract: Bioactive surface modification can be used in a variety of medical polymeric materials in the fields of biochips and biosensors, artificial membranes, and vascular grafts. In this study, the surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts, which are made of biocompatible material for the human body in the medical field. Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment on the PFTE surface using micro plasma discharge. Micro plasma was generated by a medium-frequency alternating current high-voltage generator. The preliminary modification of PTFE was conducted by a plasma of hydrogen and argon gases. The hydrocarbon thin film was deposited on modified PTFE with a mixture of acetylene and argon gases. The reactive plasma treatment using oxygen plasma was done to give biocompatible functionality to the inner wall surface. The hydrophobic surface of bare PTFE is made hydrophilic by the reactive plasma treatment due to the formation of carbonyl groups on the surface. The reactive treatment could lead to improved attachment of smooth muscle cells (SMCs) on the modified PTFE tubing. Fourier transform infrared absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle measurement were used for the analysis of the surface modification. The SMC-attached PTFE tube developed will be applicable to in vitro human vasculature

  20. limit loads for wall-thinning feeder pipes under combined bending and internal pressure

    International Nuclear Information System (INIS)

    Je, Jin Ho; Lee, Kuk Hee; Chung, Ha Joo; Kim, Ju Hee; Han, Jae Jun; Kim, Yun Jae

    2009-01-01

    Flow Accelerated Corrosion (FAC) during inservice conditions produces local wall-thinning in the feeder pipes of CANDU. The Wall-thinning in the feeder pipes is main degradation mechanisms affecting the integrity of piping systems. This paper discusses the integrity assessment of wall-thinned feeder pipes using limit load analysis. Based on finite element limit analyses, this paper compare limit loads for wall-thinning feeder pipes under combined bending and internal pressure with proposed limit loads. The limit loads are determined from limit analyses based on rectangular wall-thinning and elastic-perfectly-plastic materials using the large geometry change.

  1. Radiometric measurements of wall temperatures in the 800 K to 1150 K range for a quartz radiant heating tube

    International Nuclear Information System (INIS)

    Blevins, L.G.; Sivathanu, Y.R.; Gore, J.P.; Shahien, M.A.

    1995-01-01

    Many industrial applications require heat transfer to a load in an inert environment, which can be achieved by using gas-fired radiant tubes. A radiant tube consists of a flame confined in a cylindrical metal or ceramic chamber. The flame heats the tube wall, which in turn radiates to the load. One important characteristic of radiant heating tubes is wall temperature uniformity. Numerical models of radiant tubes have been used to predict wall temperatures, but there is a lack of experimental data for validation. Recently, Namazian et al., Singh and Gorski, and Peters et al. have measured wall temperature profiles of radiant tubes using thermocouples. 13 refs., 3 figs

  2. Light hydrogen isotopes in the single - walled carbon nano tube

    International Nuclear Information System (INIS)

    Khugaev, A.V.; Sultanov, R.A.; Guster, D.

    2007-01-01

    Full text: Progress of our understanding of the molecular hydrogen behavior in the nano tube interior open an intriguing possibility for the applications of these knowledge's to the solution of the hydrogen storage problem and light isotopes gas selectivity. That can strongly change the situation at the energy production in the world and completely change our civil life. These investigations underline the influence of the quantum effects on the properties of molecular hydrogen in the nano tube interior and it leads to the pure quantum-mechanical reformulation of the problem for the hydrogen behavior inside carbon nano tube as a problem of molecular quantum system behavior in the external field induced by the regular nano tube surface. In the present paper the molecular hydrogen behavior in the carbon nano tube was considered in the simple quantum mechanical manner. The main attention was paid to the investigation of the quantum sieving selectivity in the dependence of nano tube composition, radius and symmetry properties. For the interaction potential between hydrogen and nano tube surface was taken some phenomenological LJ(12,6) - (Lennard - Jones) potential and the external field induced by the nano tube in its interior is considered as a simple sum over the all nano tube carbon atoms. Influence of the structure of rotation (vibration) spectrum of the energy levels of diatomic molecules, such as H 2 , HD and D 2 on the final results and finite size of the nano tube along the axis of symmetry, its boundary effects is discussed in details. Thermal oscillations of nano tube surface were considered separately in the dependence of the temperature gradient along of the axis of symmetry

  3. 77 FR 3497 - Light-Walled Rectangular Pipe and Tube From Taiwan

    Science.gov (United States)

    2012-01-24

    ... Rectangular Pipe and Tube From Taiwan Determination On the basis of the record \\1\\ developed in the subject... order on light-walled rectangular pipe and tube from Taiwan would be likely to lead to continuation or recurrence of material injury to an industry in the United States within a reasonably foreseeable time. \\1...

  4. Effect of length of thinning area on the failure behavior of carbon steel pipe containing a defect of wall thinning

    International Nuclear Information System (INIS)

    Kim, Jin Weon; Park, Chi Yong

    2003-01-01

    The present study performed pipe failure tests using 102 mm-Sch. 80 carbon steel pipe with various simulated wall thinning defects, to investigate the effect of axial length of wall thinning and internal pressure on the failure behavior of pipe thinned by flow accelerated corrosion (FAC). The tests were conducted under loading conditions of four-point bending with and without internal pressure. The results showed that a failure mode of pipe with a defect depended on the magnitude of internal pressure and axial thinning length as well as stress type and thinning depth and circumferential angle. Both load carrying capability (LCC) and deformation capability (DC) were depended on stress type in the thinning area and dimensions of thinning defect. For applying tensile stress to the thinned area, the dependence of LCC on the axial length of wall thinning was determined by circumferential thinning angle, and the DC was proportionally increased with increase in axial length of wall thinning regardless of the circumferential angle. For applying compressive stress to thinned area, however, the LCC was decreased with increase in axial length of the thinned area. Also, the effect of internal pressure on failure behavior was characterized by failure mode of thinned pipe, and it promoted crack occurrence and mitigated a local buckling of the thinned area

  5. How to operate safely steam generators with multiple tube through-wall defects

    International Nuclear Information System (INIS)

    Hernalsteen, P.

    1993-01-01

    For a Nuclear Power Plant (NPP) of the Pressurized Water Reactor (PWR) type, the Steam Generator (SG) tube bundle represents the major but also the thinnest part of the primary pressure boundary. To the extent that no tube material has yet been identified to be immune to corrosion, defects may initiate in service and easily propagate through wall. While not a desirable feature, a Through Wall Deep (TWD) defect does not necessarily pose a threat to either the structural integrity or leaktightness and this paper shows how SG can (and indeed, do) operate safely and reliably while having many tubes affected by deep and even TWD defects

  6. Printable Thin Film Supercapacitors Using Single-Walled Carbon Nanotubes

    KAUST Repository

    Kaempgen, Martti

    2009-05-13

    Thin film supercapacitors were fabricated using printable materials to make flexible devices on plastic. The active electrodes were made from sprayed networks of single-walled carbon nanotubes (SWCNTs) serving as both electrodes and charge collectors. Using a printable aqueous gel electrolyte as well as an organic liquid electrolyte, the performances of the devices show very high energy and power densities (6 W h/kg for both electrolytes and 23 and 70 kW/kg for aqueous gel electrolyte and organic electrolyte, respectively) which is comparable to performance in other SWCNT-based supercapacitor devices fabricated using different methods. The results underline the potential of printable thin film supercapacitors. The simplified architecture and the sole use of printable materials may lead to a new class of entirely printable charge storage devices allowing for full integration with the emerging field of printed electronics. © 2009 American Chemical Society.

  7. Nonlinear analysis of composite thin-walled helicopter blades

    Science.gov (United States)

    Kalfon, J. P.; Rand, O.

    Nonlinear theoretical modeling of laminated thin-walled composite helicopter rotor blades is presented. The derivation is based on nonlinear geometry with a detailed treatment of the body loads in the axial direction which are induced by the rotation. While the in-plane warping is neglected, a three-dimensional generic out-of-plane warping distribution is included. The formulation may also handle varying thicknesses and mass distribution along the cross-sectional walls. The problem is solved by successive iterations in which a system of equations is constructed and solved for each cross-section. In this method, the differential equations in the spanwise directions are formulated and solved using a finite-differences scheme which allows simple adaptation of the spanwise discretization mesh during iterations.

  8. Elastic torsional buckling of thin-walled composite cylinders

    Science.gov (United States)

    Marlowe, D. E.; Sushinsky, G. F.; Dexter, H. B.

    1974-01-01

    The elastic torsional buckling strength has been determined experimentally for thin-walled cylinders fabricated with glass/epoxy, boron/epoxy, and graphite/epoxy composite materials and composite-reinforced aluminum and titanium. Cylinders have been tested with several unidirectional-ply orientations and several cross-ply layups. Specimens were designed with diameter-to-thickness ratios of approximately 150 and 300 and in two lengths of 10 in. and 20 in. The results of these tests were compared with the buckling strengths predicted by the torsional buckling analysis of Chao.

  9. Evaluation of fracture mode for local wall-thinned pipes

    International Nuclear Information System (INIS)

    Herman, Irwan; Suzuki, Tomohisa; Sato, Yasumoto; Meshii, Toshiyuki

    2007-01-01

    In this study, by referring to our burst pressure tests results, firstly, the effects of flaw length δ z and pipe size (mean radius R) on burst pressure p f were investigated by using Finite Element Method (FEM). Then, fracture mode evaluation was made by using history data of strain ratio ε z /ε θ along with load increment. Furthermore, the effect of flaw depth t 1 on fracture mode was studied and finally, the evaluation method of fracture mode for local wall-thinned pipes was introduced. (author)

  10. Current-driven vortex domain wall motion in wire-tube nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Espejo, A. P. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); Institute of Nanostructure and Solid State Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg (Germany); Vidal-Silva, N. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); López-López, J. A. [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Goerlitz, D.; Nielsch, K. [Institute of Nanostructure and Solid State Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg (Germany); Escrig, J. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Av. Ecuador 3493, 9170124 Santiago (Chile)

    2015-03-30

    We have investigated the current-driven domain wall motion in nanostructures comprised of a pair of nanotube and nanowire segments. Under certain values of external magnetic fields, it is possible to pin a vortex domain wall in the transition zone between the wire and tube segments. We explored the behavior of this domain wall under the action of an electron flow applied in the opposite direction to the magnetic field. Thus, for a fixed magnetic field, it is possible to release a domain wall pinned simply by increasing the intensity of the current density, or conversely, for a fixed current density, it is possible to release the domain wall simply decreasing the magnetic external field. When the domain wall remains pinned due to the competition between the current density and the magnetic external field, it exhibits a oscillation frequency close to 8 GHz. The amplitude of the oscillations increases with the current density and decreases over time. On the other hand, when the domain wall is released and propagated through the tube segment, this shows the standard separation between a steady and a precessional regime. The ability to pin and release a domain wall by varying the geometric parameters, the current density, or the magnetic field transforms these wire-tube nanostructures in an interesting alternative as an on/off switch nano-transistor.

  11. Experimental facility design for a gap heat transfer in a double wall tube

    International Nuclear Information System (INIS)

    Nam, Ho Yun; Hong, Jong Gan; Kim, Jong Man; Kim, Jong Bum; Jeong, Ji Young

    2012-01-01

    A reliable steam generator design is one of the most critical issues in developing a sodium cooled fast reactor (SFR), and various efforts to avoid potential sodium water reaction (SWR) have been made. For this reason, SFR steam generators have been developed to improve its reliability using a double wall tube (DWT), which has two barriers between the sodium and water. Most steam generators for SFRs are the shell and tube type. Steam at high pressure and low temperature flows inside the inner tubes, which are heated by the shell side sodium at low pressure and high temperature. Since the inner and outer tubes of conventional DWTs are made of identical materials, the degree of thermal expansion is somewhat different between the two concentric tubes owing to their temperature difference. Therefore, a greater temperature difference results in less contact pressures between the inner and outer tubes. This feature results in a deterioration of the heat transfer capability of DWTs. Current developments are focused on an improvement of heat transfer capability by investigating the gap conductance between the two concentric tubes. To improve the heat transfer capability of DWTs, it is preferable to use different tube materials (Fig. 1). It is recommended to choose the inner tube material whose thermal expansion coefficient is greater than that of the outer tube by 10 to 15%

  12. Evaluation of the inner wall axial cracks of steam generator tubes by eddy current test

    International Nuclear Information System (INIS)

    Hur, Do Haeng; Choi, Myung Sik; Lee, Doek Hyun; Han, Jung Ho

    2001-01-01

    For the enhancement of ECT reliability on the primary water stress corrosion cracks of nuclear steam generator tubes, it is important to comprehend the signal characteristics on crack morphology and to select an appropriate probe type. In this paper, the sizing accuracy and the detectability for the inner wall axial cracks of tubes were quantitatively evaluated using the electric discharge machined notches and the corrosion cracks which were developed on the operating steam generator tubes. The difference of eddy current signal characteristics between pancake and axial coil were also investigated. The results obtained from this study provide a useful information for more precise evaluation on the inner wall axial cracks of steam generator tubes.

  13. Evaluation of Eddy Current Signals from the Inner Wall Axial Cracks of Steam Generator Tubes

    International Nuclear Information System (INIS)

    Choi, Myung Sik; Hur, Do Haeng; Lee, Doek Hyun; Han, Jung Ho; Park, Jung Am

    2001-01-01

    For the enhancement of ECT reliability on the primary water stress corrosion cracks of nuclear steam generator tubes, of which the occurrence is on the increase, it is important to comprehend the signal characteristics on crack morphology and to select an appropriate probe type. In this paper, the sizing accuracy and the detectability for the inner wall axial cracks of tubes were quantitatively evaluated using the following specimens: the electric discharge machined notches and the corrosion cracks which were developed on the operating steam generator tubes. The difference of eddy current signal characteristics between pancake and axial coil were also Investigated. The results obtained from this study provide a useful information for more precise evaluation on the inner wall axial tracks oi steam generator tubes

  14. Place Atrium to Water Seal (PAWS): Assessing Wall Suction Versus No Suction for Chest Tubes After Open Heart Surgery.

    Science.gov (United States)

    Kruse, Tamara; Wahl, Sharon; Guthrie, Patricia Finch; Sendelbach, Sue

    2017-08-01

    Traditionally chest tubes are set to -20 cm H 2 O wall suctioning until removal to facilitate drainage of blood, fluid, and air from the pleural or mediastinal space in patients after open heart surgery. However, no clear evidence supports using wall suction in these patients. Some studies in patients after pulmonary surgery indicate that using chest tubes with a water seal is safer, because this practice decreases duration of chest tube placement and eliminates air leaks. To show that changing chest tubes to a water seal after 12 hours of wall suction (intervention) is a safe alternative to using chest tubes with wall suction until removal of the tubes (usual care) in patients after open heart surgery. A before-and-after quality improvement design was used to evaluate the differences between the 2 chest tube management approaches in chest tube complications, output, and duration of placement. A total of 48 patients received the intervention; 52 received usual care. The 2 groups (intervention vs usual care) did not differ significantly in complications (0 vs 2 events; P = .23), chest tube output (H 1 = 0.001, P = .97), or duration of placement (median, 47 hours for both groups). Changing chest tubes from wall suction to water seal after 12 hours of wall suction is a safe alternative to using wall suctioning until removal of the tubes. ©2017 American Association of Critical-Care Nurses.

  15. Hydrogen storage in single-wall carbon nano-tubes by means of laser excitation

    International Nuclear Information System (INIS)

    Oksengorn, B.

    2010-01-01

    A new mode for hydrogen adsorption and storage in single-wall carbon nano-tubes is used, on the basis of laser excitation. Remember that this method has been useful to obtain, in the case of the fullerene C 60 , many complex C 60 -atoms or C 60 -molecules, where atoms or molecular particles are trapped inside the C 60 -molecules. We think this method might be important to store many hydrogen molecules inside carbon nano-tubes. (author)

  16. Failure mode and fracture behavior evaluation of pipes with local wall thinning subjected to bending load

    International Nuclear Information System (INIS)

    Ahn, Seok Hwan; Nam, Ki Woo; Kim, Seon Jin; Kim, Jin Hwan; Kim, Hyun Soo; Do, Jae Yoon

    2003-01-01

    Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. In pipes of energy plants, sometimes, the local wall thinning may result from severe Erosion-Corrosion (E/C) damage. However, the effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. In this paper, the monotonic bending tests were performed of full-scale carbon steel pipes with local wall thinning. A monotonic bending load was applied to straight pipe specimens by four-point loading at ambient temperature without internal pressure. From the tests, fracture behaviors and fracture strength of locally thinned pipe were manifested systematically. The observed failure modes were divided into four types; ovalization, crack initiation/growth after ovalization, local buckling and crack initiating/growth after local buckling. Also, the strength and the allowable limit of piping system with local wall thinning were evaluated

  17. Hydrogen embrittlement corrosion failure of water wall tubes in large power station boilers

    International Nuclear Information System (INIS)

    Mathur, P.K.

    1981-01-01

    In the present paper, causes and mechanism of hydrogen embrittlement failure of water wall tubes in high pressure boilers have been discussed. A low pH boiler water environment, produced as a result of condenser leakage or some other type of system contamination and presence of internal metal oxide deposits, which permit boiler water solids to concentrate during the process of steam generation, have been ascribed to accelerate the formation of local corrosion cells conducive for acid attack resulting in hydrogen damage failure of water wall tubes. (author)

  18. Impact of Thin-Walled Projectiles with Concrete Targets

    Directory of Open Access Journals (Sweden)

    Rayment E. Moxley

    1995-01-01

    Full Text Available An experimental program to determine the response of thin-walled steel projectiles to the impact with concrete targets was recently conducted. The projectiles were fired against 41-MPa concrete targets at an impact velocity of 290 m/s. This article contains an outline of the experimental program, an examination of the results of a typical test, and predictions of projectile deformation by classical shell theory and computational simulation. Classical shell analysis of the projectile indicated that the predicted impact loads would result in circumferential buckling. A computational simulation of a test was conducted with an impact/penetration model created by linking a rigid-body penetration trajectory code with a general-purpose finite element code. Scientific visualization of the resulting data revealed that circumferential buckling was induced by the impact conditions considered.

  19. On deformation of thin-walled parts while turning on the lathes

    Directory of Open Access Journals (Sweden)

    E. V. Arbuzov

    2014-01-01

    Full Text Available In a number of industries such as aviation engineering, instrumentation engineering, etc. the nonrigid thin-walled parts are a widespread sort of products. For their turning on the lathes the specially designed arrangements are necessary to prevent parts from deformation caused by the action of cutting force and retaining pressure. To create and use the arrangements extra costs are needed, and it, as a consequence, leads to the growth of production price. Potentially, there is another approach. It is to machine using the standard arrangements under special "soft" cutting operation conditions, which are characterized by reduced forces to act on the part, thus decreasing process deformations to the appropriate level. It may be a priori expected that such approach is economically more preferable. Unfortunately, it is difficult to conduct a comparative assessment of these two alternatives to choose a preferable version because of limited data on studies and implementation of the second alternative. Thereupon, to learn the thin-walled deformations versus their treatment conditions is of interest.The aim of the paper is to have general information on topology and elastic deformation value of thin-walled parts, machined on the lathes. The objective is to assess a perspective for further potentially possible activities to develop a concept of machining the thin-walled parts with controlled deformation due to selecting the "soft" cutting operation conditions.The paper studies the thin-walled steel parts of class "Tube" and "Disk" in the role of force action with their dimensions within the range of 5-200 mm for the length, 60-250 mm for diameter, and 4-25 mm for the wall thickness. It considers a chucked work-holding scheme and two machining types, namely external turning cut (for parts of class "Tube" and cross butt turning (for parts of class "Disk". Three stages of machining have been simulated for each type of machining, namely rough (Ra 12.5; IT10

  20. The effect of atomic hydrogen adsorption on single-walled carbon nano tubes properties

    International Nuclear Information System (INIS)

    Jalili, S.; Majidi, R.

    2007-01-01

    We investigated the adsorption of hydrogen atoms on metallic single-walled carbon nano tubes using ab initio molecular dynamics method. It was found that the geometric structures and the electronic properties of hydrogenated SWNTs can be strongly changed by varying hydrogen coverage. The circular cross sections of the CNTs were changed with different hydrogen coverage. When hydrogen is chemisorbed on the surface of the carbon nano tube, the energy gap will be appeared. This is due to the degree of the Sp 3 hybridization, and the hydrogen coverage can control the band gap of the carbon nano tube

  1. Preparation of tubular urease immobilized on the inner wall of glass tube by radiation-polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Y; Hayashi, T; Kawashima, K [National Food Research Inst., Yatabe, Ibaraki (Japan); Oka, O

    1981-03-01

    A method to prepare immobilized urease on the inner wall of a glass tube by radiation-polymerization under frozen state was investigated. As a part of a continuous flow analyzer, i.w.. Technicon Auto Analyzer II, the immobilized urease tube of 1 cm length was set and used for the routine determination of urea. This flow-through system could measure urea concentration of up to 30 mM at rate of 30 samples per hour. The system were possible to assay 2000 to 3000 samples, continuously in practice. The activity of the urease tube stored in a refrigerator maintained 94% of the initial activity after 115 days.

  2. Preparation of tubular urease immobilized on the inner wall of glass tube by radiation-polymerization

    International Nuclear Information System (INIS)

    Tanaka, Yoshikazu; Hayashi, Toru; Kawashima, Koji; Oka, Osamu.

    1981-01-01

    A method to prepare immobilized urease on the inner wall of a glass tube by radiation-polymerization under frozen state was investigated. As a part of a continuous flow analyzer, i.w.. Technicon Auto Analyzer II, the immobilized urease tube of 1 cm length was set and used for the routine determination of urea. This flow-through system could measure urea concentration of up to 30 mM at rate of 30 samples per hour. The system were possible to assay 2000 to 3000 samples, continuously in practice. The activity of the urease tube stored in a refrigirator maintained 94% of the initial activity after 115 days. (author)

  3. Calculation of nonstationary two-dimensional temperature field in a tube wall in burnout

    International Nuclear Information System (INIS)

    Kashcheev, V.M.; Pykhtina, T.V.; Yur'ev, Yu.S.

    1977-01-01

    Numerically solved is a nonstationary two-dimensional equation of heat conduction for a tube wall of fuel element simulator with arbitrary energy release. The tube is heat-insulated from the outside. The vapour-liquid mixture flows inside the tube. The burnout is realized, when the heat transfer coefficient corresponds to the developed boiling in one part of the tube, and to the deteriorated regime in the other part of it. The thermal losses are regarded on both ends of the tube. Given are the statement of the problem, the algorithm of the solution, the results of the test adjusting problem. Obtained is the satisfactory agreement of calculated fixed temperature with experimental one

  4. Heat transfer enhancement in a tube using circular cross sectional rings separated from wall

    International Nuclear Information System (INIS)

    Ozceyhan, Veysel; Gunes, Sibel; Buyukalaca, Orhan; Altuntop, Necdet

    2008-01-01

    A numerical study was undertaken for investigating the heat transfer enhancement in a tube with the circular cross sectional rings. The rings were inserted near the tube wall. Five different spacings between the rings were considered as p = d/2, p = d, p = 3d/2, p = 2d and p = 3d. Uniform heat flux was applied to the external surface of the tube and air was selected as working fluid. Numerical calculations were performed with FLUENT 6.1.22 code, in the range of Reynolds number 4475-43725. The results obtained from a smooth tube were compared with those from the studies in literature in order to validate the numerical method. Consequently, the variation of Nusselt number, friction factor and overall enhancement ratios for the tube with rings were presented and the best overall enhancement of 18% was achieved for Re = 15,600 for which the spacing between the rings is 3d

  5. Probability of a steam generator tube rupture due to the presence of axial through wall cracks

    International Nuclear Information System (INIS)

    Mavko, B.; Cizelj, L.

    1991-01-01

    Using the Leak-Before-Break (LBB) approach to define tube plugging criteria a possibility to operate with through wall crack(s) in steam generator tubes may be considered. This fact may imply an increase in tube rupture probability. Improved examination techniques (in addition to the 100% tube examination) have been developed and introduced to counterbalance the associated risk. However no estimates of the amount of total increase or decrease of risk due to the introduction of LBB have been made. A scheme to predict this change of risk is proposed in the paper, based on probabilistic fracture mechanics analysis of axial cracks combined with available data of steam generator tube nondestructive examination reliability. (author)

  6. Effects of Two Purification Pretreatments on Electroless Copper Coating over Single-Walled Carbon Nano tubes

    International Nuclear Information System (INIS)

    Zheng, Z.; Li, L.; Dong, Sh.; Li, Sh.; Xiao, A.; Sun, Sh.

    2014-01-01

    To achieve the reinforcement of copper matrix composite by single-walled carbon nano tubes, a three-step-refluxing purification of carbon nano tubes sample with HNO 3 -NaOH-HCl was proposed and demonstrated. A previously reported purification process using an electromagnetic stirring with H 2 O 2 /HCl mixture was also repeated. Then, the purified carbon nano tubes were coated with copper by the same electroless plating process. At the end, the effects of the method on carbon nano tubes themselves and on copper coating were determined by transmission electron microscope spectroscopy, scanning electron microscope spectroscopy, X-ray diffractometry, thermogravimetric analysis, Fourier transformed infrared spectroscopy, and energy dispersive spectrometry. It was clearly confirmed that both of the two processes could remove most of iron catalyst particles and carbonaceous impurities without significant damage to carbon nano tubes. The thermal stability of the sample purified by H 2 O 2 /HCl treatment was slightly higher than that purified by HNO 3 -NaOH-HCl treatment. Nevertheless, the purification by HNO 3 -NaOH-HCl treatment was more effective for carboxyl functionalization on nano tubes than that by H 2 O 2 /HCl treatment. The Cu-coating on carbon nano tubes purified by both purification processes was complete, homogenous, and continuous. However, the Cu-coating on carbon nano tubes purified by H 2 O 2 /HCl was oxidized more seriously than those on carbon nano tubes purified by HNO 3 -NaOH-HCl treatment.

  7. Bioactive surface modifications on inner walls of poly-tetra-fluoro-ethylene tubes using dielectric barrier discharge

    Science.gov (United States)

    Cho, Yong Ki; Park, Daewon; Kim, Hoonbae; Lee, Hyerim; Park, Heonyong; Kim, Hong Ja; Jung, Donggeun

    2014-03-01

    Bioactive surface modification can be used in a variety of medical polymeric materials in the fields of biochips and biosensors, artificial membranes, and vascular grafts. In this study, the surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts, which are made of biocompatible material for the human body in the medical field. Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment on the PFTE surface using micro plasma discharge. Micro plasma was generated by a medium-frequency alternating current high-voltage generator. The preliminary modification of PTFE was conducted by a plasma of hydrogen and argon gases. The hydrocarbon thin film was deposited on modified PTFE with a mixture of acetylene and argon gases. The reactive plasma treatment using oxygen plasma was done to give biocompatible functionality to the inner wall surface. The hydrophobic surface of bare PTFE is made hydrophilic by the reactive plasma treatment due to the formation of carbonyl groups on the surface. The reactive treatment could lead to improved attachment of smooth muscle cells (SMCs) on the modified PTFE tubing. Fourier transform infrared absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle measurement were used for the analysis of the surface modification. The SMC-attached PTFE tube developed will be applicable to in vitro human vasculature-mimetic model systems, and to medical vascular grafts.

  8. Aspects of welding of zircaloy thin tube to end plugin the experimental welding facility of fuel element fabrication laboratory

    International Nuclear Information System (INIS)

    Shafy, M.; El-Hakim, E.

    1997-01-01

    The work was achieved within the scope of developing egyptian nuclear fuel fabrication laboratory in inshas. It showed the results of developing a welding facility for performing a qualified zircaloy-2 and 4 thin tubes to end weld joints. The welding chamber design was developed to get qualified weld for both PWR and CANDU fuel rod configurations. Experimental works for optimizing the welding parameters of tungsten inert gas (TIG) welding and electron beam (EB) welding processes were achieved. The ld penetration deeper than the wall tube thickness can be obtained for qualified end plug weld joints. It recommended to use steel compensating block for radiographic inspection of end plug weld joints. The predominate defects that can be expected in end plug weld joints, are lack of penetration and cavity. The microstructure of the fusion zone and heat affected zones are Widmanstaetten structure and its grain size is drastically sensible to the heat generation and removal of arc welding. 16 figs

  9. Effects of tube diameter and chirality on the stability of single-walled carbon nanotubes under ion irradiation

    International Nuclear Information System (INIS)

    Xu Zijian; Zhang Wei; Zhu Zhiyuan; Ren Cuilan; Li Yong; Huai Ping

    2009-01-01

    Using molecular dynamics method, we investigated the influence of tube diameter and chirality on the stability of single-walled carbon nanotubes (CNTs) under ion irradiation. We found that in the energy range below 1 keV, the dependence of CNT stability on the tube diameter is no longer monotonic under C ion irradiation, and the thinner (5, 5) CNT may be more stable than the thicker (7, 7) CNT, while under Ar irradiation, the CNT stability increases still monotonically with the CNT diameter. This stability behavior was further verified by the calculations of the threshold ion energies to produce displacement damage in CNTs. The abnormal stability of thin CNTs is related to their resistance to the instantaneous deformation in the wall induced by ion pushing, the high self-healing capacity, as well as the different interaction properties of C and Ar ions with CNT atoms. We also found that under ion irradiation the stability of a zigzag CNT is better than that of an armchair CNT with the same diameter. This is because of the bonding structure difference between the armchair and the zigzag CNTs with respect to the orientations of graphitic networks as well as the self-healing capacity difference.

  10. A thin-lip rupture of carbon steel superheater boiler tube

    International Nuclear Information System (INIS)

    Khalil, E.O.; Alzoye, K.S.; Elwaer, A.M.

    1993-01-01

    A ruptured A 42 medium carbon steel tube was collected by the engineering department in one of our steam power stations. Inspection of ruptured tube revealed a thin - lip fracture with brownish thin layer of oxide film on inner tube surfaces. There was no evidence of pitting, the outer surfaces of the tube exhibited a general oxidized conditions. A micro section taken near the fracture surface consists of ferrite and martensite, the amount of martensite decreased as we away from the fracture surface. Presence of martensite phase in the microstructure indicates that the tube material has been overheated. An erosion corrosion mechanism in conjunction with overheated. An erosion corrosion mechanism in conjunction with overheating resulted in strength deterioration with consequent premature failure. 4 fig., 1 tab

  11. Local effects in flow-accelerated corrosion wall thinning

    International Nuclear Information System (INIS)

    Pietralik, J.

    2006-01-01

    'Full text:' There is enough evidence that flow conditions play the dominant role locally in Flow-Accelerated Corrosion (FAC) under certain conditions, e.g., in CANDU feeders. While chemistry and materials set the overall potential for FAC, which can be low or high, flow conditions determine the local distribution of wall thinning. This relationship is not new and recent accurate measurements of FAC rate of a plant feeder bend confirm that the relationship between flow local conditions expressed by local mass transfer coefficient and FAC rate in CANDU feeder bends is close. There is also a lot of other direct and indirect, experimental and laboratory evidence about this relationship. This knowledge can be useful for minimizing inspection, predicting new locations for inspection, predicting the location with the highest FAC rate for a given piping component, e.g., feeder element, and determining what components or feeders and to what extent they should be replaced. It applies also to heat exchangers and steam generators. The objective of this paper is to examine the relationship between FAC rate and local flow parameters. For FAC, the most important flow parameter is mass transfer coefficient. The mass transfer coefficient describes the intensity of the transport of corrosion products from the oxide-water interface into the bulk water. Therefore, this parameter can be used for predicting the local distribution of FAC rate. It could also be used in planning experiments because time-varying surface roughness can explain the time-dependence of FAC rates. The paper presents plant and laboratory evidence about the relationship. In addition, it shows correlations for mass transfer coefficient in components that are highly susceptible to FAC. The role of surface roughness, wall shear stress, and local turbulence is also discussed. (author)

  12. 76 FR 64312 - Light-Walled Welded Rectangular Carbon Steel Tubing From Taiwan: Final Results of the Expedited...

    Science.gov (United States)

    2011-10-18

    ... Rectangular Carbon Steel Tubing From Taiwan: Final Results of the Expedited Sunset Review of the Antidumping... the antidumping duty order on light-walled welded rectangular carbon steel tubing from Taiwan pursuant... steel tubing from Taiwan pursuant to section 751(c) of the Act. See Initiation of Five-Year (``Sunset...

  13. Antimicrobial Activity of Single-Walled Carbon Nano tubes Suspended in Different Surfactants

    International Nuclear Information System (INIS)

    Dong, L.; Alex Henderson, A.; Field, Ch.

    2012-01-01

    We investigated the antibacterial activity of single-walled carbon nano tubes (SWCNTs) dispersed in surfactant solutions of sodium cholate, sodium dodecylbenzene sulfonate, and sodium dodecyl sulfate. Among the three surfactants, sodium cholate demonstrated the weakest antibacterial activity against Salmonella enterica, Escherichia coli, and Enterococcus faecium and thereby was used to disperse bundled SWCNTs in order to study nano tube antibiotic activity. SWCNTs exhibited antibacterial characteristics for both S. enterica and E. coli. With the increase of nano tube concentrations from 0.3 mg/mL to 1.5 mg/mL, the growth curves had plateaus at lower absorbance values whereas the absorbance value was not obviously affected by the incubation ranging from 5?min to 2 h. Our findings indicate that carbon nano tubes could become an effective alternative to antibiotics in dealing with drug-resistant and multidrug-resistant bacterial strains because of the physical mode of bactericidal action that SWCNTs display

  14. Preparation of Multi-walled Carbon Nano tubes/ Natural Rubber Composite by Wet Mixing Method

    International Nuclear Information System (INIS)

    Azira Abdul Aziz; Azira Abdul Aziz; Che Su Mat Saad; Mohamad Rusop Mahmood

    2011-01-01

    Natural rubber/multi-walled carbon nano tubes (Nr/MWCNTs) nanocomposite is formed by incorporating nano tubes in a polymer solution and subsequently evaporating the solvent. Using this technique, nano tubes will be dispersed homogeneously in the NR matrix in an attempt to increase the mechanical properties of these nano composites. Mechanical test results show an increase in the tensile strength for up to 19 times in relation to pure NR. In addition to mechanical testing, the morphology of the MWNTs into NR was studied by Field Emission Scanning Electron Microscopy (FESEM) in order to understand the morphology of the resulting system. Slight shift noted from Raman analyses from each different wt. % of MWCNTs with the NR due to the stress transfer that indicates reinforcement of the nano tubes. (author)

  15. Design optimization of a thin walled pressure vessel

    International Nuclear Information System (INIS)

    Sadiq, S.

    2001-01-01

    Design evaluation of a pressure vessel is not only to build confidence on its integrity but also to reduce structural weight and enhance the performance of the structure. Pressure vessel, e.g., a rocket motor not only has to withstand the high operating temperatures but it must also be able to survive the internal pressures and external aerodynamic forces and bending stresses during its operation in flight. A research program was devised to study the stresses, which are generated in a thin walled pressure vessel during actual operation and its simulation with cold testing technique, i.e., by means of hydrostatic testing employing electrical resistance strain gauges on the external surface of the cylinder. The objective of the research was to uphold the performance of the vessel by reducing its thickness from 6.09 to 5.5 mm (which of course reduces the safety factor margin from 1.8 to 1.5); thereby curtailing the overall structural weight and maintaining the efficiency of the vessel itself during its live operation. The techniques employed were hydrostatic testing, data acquisition system for obtaining data on strains from the electrical resistance strain gauges and later employing V on Mises yield criterion empirical relation to computer the stresses in hoop and longitudinal directions. (author)

  16. Simulations and Experiments on Vibration Control of Aerospace Thin-Walled Parts via Preload

    Directory of Open Access Journals (Sweden)

    Qiong Wu

    2017-01-01

    Full Text Available Thin-walled parts primarily comprise the entire piece of rough machining, and the material removal rate can surpass 95%. Numerous components with thin-walled structures are preferred in the aerospace industry for their light weight, high strength, and other advantages. In aerospace thin-walled workpiece machining processes and practical applications, they are excited by the vibration. The preload changing the modal stiffness of the part is found and this change causes continuous changes in the natural frequency. Researching on the influence of pretightening force on dynamic characteristics of thin-walled components is highly significant for controlling vibration. In this study, the typical aviation thin-walled part is the research object. Finite element numerical simulation and experimental verification are employed to analyze the dynamic characteristics of 7075 aluminum alloy thin-walled plates under different preloads for exploring the relationship between natural frequency and preload. The relationship is validated by comparative results. Both the simulation and experimental results show that the natural frequencies of plates increase following the augmentation of the preload. Thus, this research introduces the method where vibration of aerospace thin-walled parts is reduced by preload. For practical engineering application, a program showing the relationship between natural frequency and preload is written using Visual Basic language.

  17. Safety assessment of pipes with multiple local wall thinning defects under pressure and bending moment

    International Nuclear Information System (INIS)

    Peng Jian; Zhou Changyu; Xue Jilin; Dai Qiao; He Xiaohua

    2011-01-01

    The safety assessment of pipes with local wall thinning defects is highly important in engineering. Most attention has been paid on the safety assessment of pipe with single local wall thinning defect, while the studies about multiple local wall thinning defects are not nearly enough. However, the interaction of multiple local wall thinning defects in some conditions is great, and may have a great impact on the safety assessment. In the present standard API 579/ASME FFS, the safety assessment of pipes with multiple local wall thinning defects is given, while as well as the influence of load condition, the influences of arrangement and relative depth of defects are ignored, which may influence the safety assessment considerably. In this paper, the influence of the interaction between multiple local wall thinning defects on the remaining strength of pipes at different arrangements and depths of defects under different load conditions (pressure, tension-bending moment and compression-bending moment) are studied. A quantified index is defined to describe the interaction between defects quantitatively. For different arrangements and relative depths of defects, based on a limit value 0.05 of the quantified index of the interaction between defects, a relatively systematic safety assessment of pipes with multiple local wall thinning defects under different load conditions has been proposed.

  18. Fabrication of seamless calandria tubes

    International Nuclear Information System (INIS)

    Saibaba, N.; Phanibabu, C.; Bhaskara Rao, C.V.; Kalidas, R.; Ganguly, C.

    2002-01-01

    Full text: Calandria tube is a large diameter, thin walled zircaloy-4 tube and is an important structural component of PHWR type of reactors. These tubes are lifetime components and remain during the full life of the reactor. Calandria tubes are classified as extremely thin walled tubes with a diameter to wall thickness ratio of around 96. Such thin walled tubes are conventionally produced by seam welded route comprising of extrusion of slabs followed by a series of hot and rolling passes, shaping into O-shape and eventual welding. An alternative and superior method of fabricating the calandria tubes, the seamless route, has been developed, which involves hot extrusion of mother blanks followed by three successive cold pilger reductions. Eccentricity correction of the extruded blanks is carried out on a special purpose grinding equipment to bring the wall thickness variation within permissible limits. Predominant wall thickness reductions are given during cold pilgering to ensure high Q-factor values. The texture in the finished tubes could be closely, controlled with an average f r value of 0.65. Pilgering parameters and tube guiding system have been specially designed to facilities rolling of thin walled tubes. Seamless calandria tubes have distinct advantages over welded tubes. In addition to the absence of weld, they are dimensionally more stable, lighter in weight and possess uniform grains with superior grain size. The cycle time from billet to finished product is substantially reduced and the product is amenable to high level of quality assurance. The most significant feature of the seamless route is its material recovery over welded route. Residual stresses measured in the tubes indicate that these are negligible and uniform along the length of the tube. In view of their superior quality, the first charge of seamless calandria tubes will be rolled into the first 500 MWe Pressurised Heavy Water Reactor at Tarapur

  19. SCF analysis of a pressurized vessel-nozzle intersection with wall thinning damage

    International Nuclear Information System (INIS)

    Qadir, M.; Redekop, D.

    2009-01-01

    A three-dimensional finite element analysis is carried out of a pressurized vessel-nozzle intersection (tee joint), with wall thinning damage. A convergence-validation study is first carried out for undamaged intersections, in which comparisons are made with previously published work for the stress concentration factor (SCF), and good agreement is observed. A study is then carried out for specific tee joints to examine the effect on the SCF of varying the extent of the wall thinning damage. Finally, a parametric study is conducted in which the SCF is computed for a wide range of tee joints, initially considered undamaged, and then with wall thinning damage.

  20. Dynamics of plane-symmetric thin walls in general relativity

    International Nuclear Information System (INIS)

    Wang, A.

    1992-01-01

    Plane walls (including plane domain walls) without reflection symmetry are studied in the framework of Einstein's general relativity. Using the distribution theory, all the Einstein field equations and Bianchi identities are split into two groups: one holding in the regions outside of the wall and the other holding at the wall. The Einstein field equations at the wall are found to take a very simple form, and given explicitly in terms of the discontinuities of the metric coefficients and their derivatives. The Bianchi identities at the wall are also given explicitly. Using the latter, the interaction of a plane wall with gravitational waves and some specific matter fields is studied. In particular, it is found that, when a gravitational plane wave passes through a wall, if the wall has no reflection symmetry, the phenomena, such as reflection, stimulation, or absorption, in general, occur. It is also found that, unlike for gravitational waves, a massless scalar wave or an electromagnetic wave continuously passes through a wall without any reflection. The repulsion and attraction of a plane wall are also studied. It is found that the acceleration of an observer who is at rest relative to the wall usually consists of three parts: one is due to the force produced by the wall, the second is due to the force produced by the space-time curvature, which is zero if the wall has reflection symmetry, and the last is due to the accelerated motion of the wall. As a result, a repulsive (attractive) plane wall may not be repulsive (attractive) at all. Finally, the collision and interaction among the walls are studied

  1. Pectin and the role of the physical properties of the cell wall in pollen tube growth of Solanum chacoense.

    Science.gov (United States)

    Parre, Elodie; Geitmann, Anja

    2005-02-01

    The cell wall is one of the structural key players regulating pollen tube growth, since plant cell expansion depends on an interplay between intracellular driving forces and the controlled yielding of the cell wall. Pectin is the main cell wall component at the growing pollen tube apex. We therefore assessed its role in pollen tube growth and cytomechanics using the enzymes pectinase and pectin methyl esterase (PME). Pectinase activity was able to stimulate pollen germination and tube growth at moderate concentrations whereas higher concentrations caused apical swelling or bursting in Solanum chacoense Bitt. pollen tubes. This is consistent with a modification of the physical properties of the cell wall affecting its extensibility and thus the growth rate, as well as its capacity to withstand turgor. To prove that the enzyme-induced effects were due to the altered cell wall mechanics, we subjected pollen tubes to micro-indentation experiments. We observed that cellular stiffness was reduced and visco-elasticity increased in the presence of pectinase. These are the first mechanical data that confirm the influence of the amount of pectins in the pollen tube cell wall on the physical parameters characterizing overall cellular architecture. Cytomechanical data were also obtained to analyze the role of the degree of pectin methyl-esterification, which is known to exhibit a gradient along the pollen tube axis. This feature has frequently been suggested to result in a gradient of the physical properties characterizing the cell wall and our data provide, for the first time, mechanical support for this concept. The gradient in cell wall composition from apical esterified to distal de-esterified pectins seems to be correlated with an increase in the degree of cell wall rigidity and a decrease of visco-elasticity. Our mechanical approach provides new insights concerning the mechanics of pollen tube growth and the architecture of living plant cells.

  2. Magnesium diboride on inner wall of copper tube: A test case for superconducting radio frequency cavities

    Directory of Open Access Journals (Sweden)

    Wenura K. Withanage

    2017-10-01

    Full Text Available Superconductor magnesium diboride is considered one of the viable materials to substitute bulk niobium for superconducting radio frequency cavities. Utilizing a MgB_{2} coating on the inner wall of a copper cavity will allow operation at higher temperatures (20–25 K than Nb cavities due to the high transition temperature of MgB_{2} (39 K and the high thermal conductivity of Cu. In this paper, we present results of MgB_{2} coating on Cu tubes with similar dimensions to a 3 GHz cavity, as the first step towards coating the actual cavity, using the hybrid physical chemical vapor deposition technique. The results show successful coating of a uniform MgB_{2} layer on the inner wall of the Cu tubes with T_{c} as high as 37 K.

  3. Magnesium diboride on inner wall of copper tube: A test case for superconducting radio frequency cavities

    Science.gov (United States)

    Withanage, Wenura K.; Lee, N. H.; Penmatsa, Sashank V.; Wolak, M. A.; Nassiri, A.; Xi, X. X.

    2017-10-01

    Superconductor magnesium diboride is considered one of the viable materials to substitute bulk niobium for superconducting radio frequency cavities. Utilizing a MgB2 coating on the inner wall of a copper cavity will allow operation at higher temperatures (20-25 K) than Nb cavities due to the high transition temperature of MgB2 (39 K) and the high thermal conductivity of Cu. In this paper, we present results of MgB2 coating on Cu tubes with similar dimensions to a 3 GHz cavity, as the first step towards coating the actual cavity, using the hybrid physical chemical vapor deposition technique. The results show successful coating of a uniform MgB2 layer on the inner wall of the Cu tubes with Tc as high as 37 K.

  4. Numerical simulation of heat fluxes in a two-temperature plasma at shock tube walls

    International Nuclear Information System (INIS)

    Kuznetsov, E A; Poniaev, S A

    2015-01-01

    Numerical simulation of a two-temperature three-component Xenon plasma flow is presented. A solver based on the OpenFOAM CFD software package is developed. The heat flux at the shock tube end wall is calculated and compared with experimental data. It is shown that the heat flux due to electrons can be as high as 14% of the total heat flux. (paper)

  5. Numerical simulation of heat fluxes in a two-temperature plasma at shock tube walls

    Science.gov (United States)

    Kuznetsov, E. A.; Poniaev, S. A.

    2015-12-01

    Numerical simulation of a two-temperature three-component Xenon plasma flow is presented. A solver based on the OpenFOAM CFD software package is developed. The heat flux at the shock tube end wall is calculated and compared with experimental data. It is shown that the heat flux due to electrons can be as high as 14% of the total heat flux.

  6. Pipe Wall Thinning Evaluation through the Arrival Time Delay of A0 Lamb Wave Using Magnetostrictive Patch Transducers

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seung Hyun; Kwon, Hyu Sang; Ahn, Bong Young; Lee, Seung Seok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2008-12-15

    Guided wave technology is advantageous for fast inspection of pipe wall thinning since the guided wave propagates long distance. In this investigation, the method to evaluate gradual wall thinning in a pipe based on the arrival time delay with magnetostrictive patch transducers is presented. Low frequency A0 Lamb waves were generated and measured by the present transducer and it was applied to arrival time delay measurement experiments on a test pipe having gradual wall thinnings artificially manufactured. From experiments, consistent results that wall thinning increases the arrival time delay of A0 waves were obtained. Consequently, the feasibility of the magnetostrictive patch transducers to evaluate wall thinning was verified

  7. Pipe Wall Thinning Evaluation through the Arrival Time Delay of A0 Lamb Wave Using Magnetostrictive Patch Transducers

    International Nuclear Information System (INIS)

    Cho, Seung Hyun; Kwon, Hyu Sang; Ahn, Bong Young; Lee, Seung Seok

    2008-01-01

    Guided wave technology is advantageous for fast inspection of pipe wall thinning since the guided wave propagates long distance. In this investigation, the method to evaluate gradual wall thinning in a pipe based on the arrival time delay with magnetostrictive patch transducers is presented. Low frequency A0 Lamb waves were generated and measured by the present transducer and it was applied to arrival time delay measurement experiments on a test pipe having gradual wall thinnings artificially manufactured. From experiments, consistent results that wall thinning increases the arrival time delay of A0 waves were obtained. Consequently, the feasibility of the magnetostrictive patch transducers to evaluate wall thinning was verified

  8. Development of assessment methodology for locally wall-thinned pipe under combined loading

    International Nuclear Information System (INIS)

    Shim, Do Jun; Kim, Yun Jae; Kim, Young Jin; Park, Chi Yong

    2005-01-01

    Recently authors have proposed a new method to estimate failure strength of a pipe with local wall thinning subject to either internal pressure or global bending. The proposed method was based on the equivalent stress averaged over the minimum ligament in the locally wall thinned region, and the simple scheme to estimate the equivalent stress in the minimum ligament was proposed, based on the reference stress concept. This paper extends the new method to combined internal pressure and global bending. The proposed method is validated against FE results for various geometries of local wall thinning under combined loading. The effect of internal pressure is also investigated in the present study. Comparison of maximum moments, predicted according to the proposed method, with published full-scale pipe test data for locally wall-thinned pipes under combined internal pressure and global bending, shows good agreement

  9. PHYSICAL BASES OF SYSTEMS CREATION FOR MAGNETIC-IMPULSIVE ATTRACTION OF THIN-WALLED SHEET METALS

    Directory of Open Access Journals (Sweden)

    Y. Batygin

    2009-01-01

    Full Text Available The work is dedicated to the physical base of systems creating for the thin-walled sheet metals magnetic pulse attraction. Some practical realization models of the author’s suggestions are represented.

  10. Influences of overload on low cycle fatigue behaviors of elbow pipe with local wall thinning

    International Nuclear Information System (INIS)

    Sato, Kyohei; Ogino, Kanako; Takahashi, Koji; Ando, Kotoji; Urabe, Yoshio

    2011-01-01

    Low cycle fatigue tests were conducted using 100A elbow pipe specimens with or without local wall thinning. Local wall thinning was machined on the inside of the extrados of test elbows to simulate metal loss due to flow-accelerated corrosion or liquid droplet impingement erosion. Low cycle fatigue tests were carried out under displacement control with an inner pressure of 9 MPa. To simulate seismic events, low cycle fatigue tests were carried out on elbow pipe subjected to cyclic overloads. Regardless of local wall thinning, fatigue life of overload pipe was not so different from that of the non-overload pipe in appearance. Miner's rule can be applied to evaluate fatigue life of the elbow pipes with and without wall thinning, even if overload is applied. (author)

  11. Experimental High Speed Milling of the Selected Thin-Walled Component

    Directory of Open Access Journals (Sweden)

    Jozef Zajac

    2017-11-01

    Full Text Available In a technical practice, it is possible to meet thin-walled parts more and more often. These parts are most commonly used in the automotive industry or aircraft industry to reduce the weight of different design part of cars or aircraft. Presented article is focused on experimental high speed milling of selected thin-walled component. The introduction of this article presents description of high speed machining and specification of thinwalled parts. The experiments were carried out using a CNC machine Pinnacle VMC 650S and C45 material - plain carbon steel for automotive components and mechanical engineering. In the last part of the article, described are the arrangements to reduction of deformation of thin-walled component during the experimental high speed milling.

  12. Study on Mechanical Behavior of Thin-walled Member during Precision Straightening Process

    Directory of Open Access Journals (Sweden)

    Ben Guan

    2014-09-01

    Full Text Available This paper introduces the mechanical behavior of precise straightening thin-walled members systematically. As a result of its cross section characteristics of the thin-walled members, traditional straightening theory does not work well in the straightening process of this kind of metal bar stock. Considering the stress evolvement of section during the straightening process, a model was built to analysis the straightening process like thin-walled member with great section height. By making a thorough analysis of the straightening process, the section deformation law and the relationship between sectional distortion and straightening parameters has been mastered. An analytical model was built for macroscopic energetics parameters of the straightening process and the parameters was optimized based on this model. Then loading mode of thin-walled member straightening was discussed.

  13. Study of residual stresses and plastic strains in expanded thin tubes

    International Nuclear Information System (INIS)

    Hassine, T.; Inglebert, G.; Point, N.

    1993-01-01

    The measurement of residual stresses with X-rays or with extending gauges, on expanded tubes, implies a longitudinal cutting up. The cutting-up provokes an elastic relaxing of the stresses and this is particularly important for thin tubes. The initial stresses and the geometry influence the variation of the stresses along the tube. The determination of the relaxed stresses is possible in certain cases with extending gauges measurements, but this determination is difficult and expensive. In order to analytically correct these stresses, some assumptions are used and verified with a finite element model. (author). 3 refs., 5 figs

  14. A risk approach to the management of boiler tube thinning

    International Nuclear Information System (INIS)

    Noori, Soudabeh A.; Price, John W.H.

    2006-01-01

    A large set of industrial thickness inspection data covering four boiler units of a power station over a period of five years was made available to the authors. The measurements were made in regions of the boiler where corrosion/erosion was the major cause of failure of the boiler tubes. There were over 40,000 separately measured data points in the data and all were collected with some care and expense. In the development of maintenance strategies for equipment, this type of data is typical of the data that must be collected and assessed. This data thus represents an opportunity to evaluate the ability to generate a useful risk approach to the management of the tubing. An important example of a risk-based approach is the American Petroleum Institute (API) Risk Based Inspection ('RBI'), API 581. A variety of problems were encountered applying this to boiler tubes. The problems include irrelevant API 581 corrosion rate tables, lack of information on how to analyse inspection data, difficulty of dealing with multiple inspection categories and lack of suitable direction for programming inspection intervals

  15. Novel Adaptive Fixturing for Thin Walled Aerospace Parts

    International Nuclear Information System (INIS)

    Merlo, Angelo; Ricciardi, Donato; Salvi, Edoardo; Fantinati, Dario; Iorio, Ernesto

    2011-01-01

    In the aerospace industry the monolithic structures have been introduced to reduce the costs of assembling large numbers of components. The expected benefit of using thin walled monolithic parts is given by a large reduction in the overall manufacturing costs, nevertheless this kind of component encounters a critical phase in fixturing. Fixtures are used to locate and hold workpieces during manufacturing. Because workpiece surface errors and fixture set-up errors (called source errors) always exist, the fixtured workpiece will consequently have position and/or orientation errors (called resultant errors) that will definitely affect the final machining accuracy. Most often the current clamping procedure is not straightforward, it implies several steps and the success of the operation hardly depends by the skill of the human operator. It is estimated that fixturing could constitute 10-20% of the total manufacturing costs, assuming that the fixtures are amortized over relatively small batches. Fixturing devices must satisfy two requisites, which, in some terms, are opposite: - to provide relatively high forces in order to guarantee that the workpiece will be maintained in position under the maximum cutting forces; - to reduce as much as possible strains induced in the workpiece. Limiting the strains induced in the workpiece is crucial because of elastic strain recovery: releasing the clamped workpiece would result in an unwanted final deformation. In this paper a novel adaptive fixturing based on active clamping forces (supplied by piezoelectric actuators) is presented: a real aerospace part case study, - a Nozzle Guide Vane (NGV) -, is introduced, the related problems are identified, and the adopted solutions shown. The proposed adaptive fixturing device can lead to the following advantages: - to perform an automatic errors-free workpiece clamping and then drastically reduce the overall fixturing set up time; - to recover unwanted strains induced to the workpiece, in

  16. Ultrasonic wall thickness gauging for ferritic steam generator tubing as an in-service inspection tool

    International Nuclear Information System (INIS)

    Haesen, W.M.J.; Tromp, Th.J.

    1980-01-01

    In-service inspection of LWR steam generators is more or less a standard routine operation. The situation can be very different for LMFBRs. For the SNR 300 (Kalkar Power Station) the situation is different because the steam generators have ferritic tubing. The tube walls are comparatively thick, 2 to 4.5 mm. During inservice examinations the steam generators will be drained on both sides, however on the sodium side a sodium film will be present. Furthermore the SNR 300 will have two types of steam generator. A straight tube design and a helical coil design will be used. Both types consist of a evaporator and superheater. The steam generators are of course not radioactive. It is obvious that in this case the eddy current (EC) technique is not an enviable inservice inspection tool. Basically EC is a surface flaw detection technique. Only the saturation magnetisation method will improve the EC technique sufficiently for ferritic material. However the 'in bore examination' with the saturation technique was, in case of the SNR 300 steam generator tubing, considered impossible since the inner diameters are fairly small. Furthermore sodium traces may influence the EC method. Although multifrequency methods can solve this problem, EC is not considered as a useful tool for examining ferritic tubing. Another method is to employ the 'stray flux' method which is under development with the TNO organization in Holland. The EC and stray flux method do have one drawback, these methods do not detect gradual changes in wall thickness. Ultrasonic examinations will be used in the SNR 300 as the main inspection tool for the steam generators. In this paper the reasons why ultrasonic examination was selected are explained. The results of the development work on this subject are discussed

  17. Laminar free convection in a vertical tube with constant wall temperature considering the variation of fluid properties

    International Nuclear Information System (INIS)

    Senna, J.G.

    1981-01-01

    A model to analyze Laminar Free convection with variable properties in the entrance of a vertical open tube with constant wall temperature and for one Prandtl number (0.7), is studied. The velocity and temperature profiles are determined by finite difference methods for different rates of wall to ambient temperatures and different values of the velocity in the entrance of the tube. The results will be compared with those obtained in the same problem with constant properties. (Author) [pt

  18. Prevalence and histopathological finding of thin-walled and thick-walled Sarcocysts in slaughtered cattle of Karaj abattoir, Iran.

    Science.gov (United States)

    Nourollahi-Fard, Saeid R; Kheirandish, Reza; Sattari, Saeid

    2015-06-01

    Sarcocystosis is a zoonotic disease caused by Sarcocystis spp. with obligatory two host life cycle generally alternating between an herbivorous intermediate host and a carnivorous definitive host. Some species of this coccidian parasite can cause considerable morbidity and mortality in cattle. The present study was set to investigate the prevalence of Sarcocystis spp. and type of cyst wall in slaughtered cattle of Karaj abattoir, Iran. For this purpose 125 cattle (88 males and 37 females) were investigated for the presence of macroscopic and microscopic Sarcocystis cysts in muscular tissues. No macroscopic Sarcocystis cysts were found in any of the samples. In light microscopy, 121 out of 125 cattle (96.8 %) had thin-walled cysts of Sarcocystis cruzi, while 43 out of them (34.4 %) had thick-walled Sarcocystis cyst. In this survey, the most infected tissue was esophagus and heart and the less was diaphragm. Thin-walled cysts (S. cruzi) mostly found in heart and skeletal muscle showed the less. However, thick-walled cyst (S. hominis or S. hirsuta) mostly were detected in diaphragm, heart muscle showed no thick-walled cyst. No significant relation was observed between age and sex and the rate of infection. The results showed that Sarcocystis cyst is prevalent in cattle in the North part of Iran and the evaluation of infection potential can be useful when considering control programs.

  19. Dissecting the regulation of pollen tube growth by modelling the interplay of hydrodynamics, cell wall and ion dynamics

    Directory of Open Access Journals (Sweden)

    Junli eLiu

    2014-08-01

    Full Text Available Hydrodynamics, cell wall and ion dynamics are all important properties that regulate pollen tube growth. Currently, the two main pollen tube growth models, the cell wall model and the hydrodynamic model do not appear to be reconcilable. Here we develop an integrative model for pollen tube growth and show that our model reproduces key experimental observations: 1 that the hypertonic condition leads to a much longer oscillatory period and that the hypotonic condition halves the oscillatory period; 2 that oscillations in turgor are experimentally undetectable; 3 that increasing the extracellular calcium concentration or decreasing the pH decreases the growth oscillatory amplitude; 4 that knockout of Raba4d, a member of the Rab family of small GTPase proteins, decreases pollen tube length after germination for 24 hours. Using the model generated here, we reveal that 1 when cell wall extensibility is large, pollen tube may sustain growth at different volume changes and maintain relatively stable turgor; 2 turgor increases if cell wall extensibility decreases; 3 increasing turgor due to decrease in osmolarity in the media, although very small, increases volume change . However, increasing turgor due to decrease in cell wall extensibility decreases volume change. In this way regulation of pollen tube growth by turgor is context dependent. By changing the osmolarity in the media, the main regulatory points are extracellular osmolarity for water flow and turgor for the volume encompassed by the cell wall. However, if the viscosity of cell wall changes, the main regulatory points are turgor for water flow and wall extensibility for the volume encompassed by the cell wall. The novel methodology developed here reveals the underlying context-dependent regulatory principle of pollen tube growth.

  20. 77 FR 5240 - Light-Walled Welded Rectangular Carbon Steel Tubing From Taiwan: Continuation of Antidumping Duty...

    Science.gov (United States)

    2012-02-02

    ... Rectangular Carbon Steel Tubing From Taiwan: Continuation of Antidumping Duty Order AGENCY: Import... revocation of the antidumping duty order on light-walled welded rectangular carbon steel tubing from Taiwan would likely lead to a continuation or recurrence of dumping and material injury to an industry in the...

  1. 76 FR 33200 - Light-Walled Rectangular Pipe and Tube from Turkey; Notice of Preliminary Results of Antidumping...

    Science.gov (United States)

    2011-06-08

    ...) metallic coating; (3) painted/non-painted; (4) perimeter; (5) wall thickness; and (6) shape. See the... pipe and tube from Turkey. Atlas Tube, Inc. and Searing Industries, Inc. are petitioners in this case... through April 2010. Our analysis indicated, based on record evidence, that the appropriate date of sale of...

  2. Detection of wall thinning of carbon steel pipe covered with insulation using Pulsed Eddy Current technique

    International Nuclear Information System (INIS)

    Park, Duckgun; Kishore, M. B.; Lee, D. H.

    2013-01-01

    The test sample is a ferromagnetic carbon steel pipe having different thickness, covered with a 10 cm plastic insulation laminated by 0.4 mm Al plate to simulate the pipelines in NPPs. The PEC Probe used for the wall thinning detection consists of an excitation coil and a Hall sensor. The excitation coils in the probe is driven by a rectangular bipolar current pulse and the Hall-sensor will detects the resultant field. The Hall sensor output is considered as PEC signal. Results shows that the PEC system can detect wall thinning in an insulated pipeline of the NPPs. Local wall thinning in pipelines affects the structural integrity of industries like nuclear power plants (NPPs). In the present study a pulsed eddy current (PEC) technology to detect the wall thing of carbon steel pipe covered with insulation is developed

  3. Application of elastic wave dispersion relations to estimate thermal properties of nanoscale wires and tubes of varying wall thickness and diameter

    International Nuclear Information System (INIS)

    Bifano, Michael F P; Kaul, Pankaj B; Prakash, Vikas

    2010-01-01

    This paper reports dependency of specific heat and ballistic thermal conductance on cross-sectional geometry (tube versus rod) and size (i.e., diameter and wall thickness), in free-standing isotropic non-metallic crystalline nanostructures. The analysis is performed using dispersion relations found by numerically solving the Pochhammer-Chree frequency equation for a tube. Estimates for the allowable phonon dispersion relations within the crystal lattice are obtained by modifying the elastic acoustic dispersion relations so as to account for the discrete nature of the material's crystal lattice. These phonon dispersion relations are then used to evaluate the specific heat and ballistic thermal conductance in the nanostructures as a function of the nanostructure geometry and size. Two major results are revealed in the analysis: increasing the outer diameter of a nanotube while keeping the ratio of the inner to outer tube radius (γ) fixed increases the total number of available phonon modes capable of thermal population. Secondly, decreasing the wall thickness of a nanotube (i.e., increasing γ) while keeping its outer diameter fixed, results in a drastic decrease in the available phonon mode density and a reduction in the frequency of the longitudinal and flexural acoustic phonon modes in the nanostructure. The dependency of the nanostructure's specific heat on temperature indicates 1D, 2D, and 3D geometric phonon confinement regimes. Transition temperatures for each phonon confinement regime are shown to depend on both the nanostructure's wall thickness and outer radius. Compared to nanowires (γ = 0), the frequency reduction of acoustic phonon modes in thinner walled nanotubes (γ = 0.96) is shown to elevate the ballistic thermal conductance of the thin-walled nanotube between 0.2 and 150 K. At 20 K, the ballistic thermal conductance of the thin-walled nanotube (γ = 0.96) becomes 300% greater than that of a solid nanowire. For temperatures above 150 K, the trend

  4. Anharmonic properties of Raman modes in double wall carbon nano tubes

    Energy Technology Data Exchange (ETDEWEB)

    Marquina, J. [Universidad de los Andes, Facultad de Ciencias, Centro de Estudios Avanzados en Optica, 5101 Merida (Venezuela, Bolivarian Republic of); Power, Ch.; Gonzalez, J. [Universidad de los Andes, Facultad de Ciencias, Centro de Estudios en Semiconductores, 5101 Merida (Venezuela, Bolivarian Republic of); Broto, J. M. [Universite de Toulouse, Laboratoire National des Champs Magnetiques Intenses, CNRS UPR 3228, 31400 Toulouse (France); Flahaut, E., E-mail: castella@ula.v [Universite Paul Sabatier, Laboratoire de Chimie des Materiaux Inorganiques, UMR CNRS 5085, 31062 Toulouse (France)

    2011-07-01

    The temperature dependence of the radial breathing modes (RB Ms) and the zone-center tangential optical phonons (G-bands) of double-walled carbon nano tubes has been investigated between 300 and 700 K using Raman scattering. As expected, with increasing temperature, the frequencies of the Raman peaks, including the RB Ms and G-bands downshift simultaneously. We show here that the temperature dependence of the RB Ms can be fitted by a simple linear dependence and different RB Ms have different frequency shifts. We observe a noticeable nonlinearity in the temperature dependence of the G-band associated with the outer semiconducting tube G+ext (s). The deviation from the linear trend is due to the contribution of the third-order anharmonic term in the lattice potential energy with a pure temperature effect. An estimated value of 1.5 for the Grueneisen parameter of the G+ext (s) band was found. (Author)

  5. A study of cladding technology on tube wall surface by a hand-held laser torch

    International Nuclear Information System (INIS)

    Terada, Takaya; Nishimura, Akihiko; Oka, Kiyoshi; Moriyama, Taku; Matsuda, Hiroyasu

    2015-01-01

    New maintenance technique was proposed using a hand-held laser torch for aging chemical plants and power plants. The hand-held laser torch was specially designed to be able to access limited tubular space in various cases. A composite-type optical fiberscope was composed of a center fiber for beam delivery and surrounded fibers for visible image delivery. Laser irradiation on a work pieces with the best accuracy of filler wire was carried out. And, we found that the optimized wire-feed speed was 2 mm/s in laser cladding. We succeeded to make a line clad on the inner wall of 23 mm tube. This technique was discussed to be applied to the maintenance for cracks or corrosions of tubes in various harsh environments. (author)

  6. Modelling complex draft-tube flows using near-wall turbulence closures

    Energy Technology Data Exchange (ETDEWEB)

    Ventikos, Y.; Sotiropoulos, F. [Georgia Institute of Technology, Atlanta, GA (United States). School of Civil and Environmental Engineering; Patel, V.C. [Univ. of Iowa, Iowa City, IA (United States). Iowa Institute of Hydraulic Research

    1996-12-31

    This paper presents a finite-volume method for simulating flows through complex hydroturbine draft-tube configurations using near-wall turbulence closures. The method employs the artificial-compressibility pressure-velocity coupling approach in conjunction with multigrid acceleration for fast convergence on very fine grids. Calculations are carried out for a draft tube with two downstream piers on a computational mesh consisting of 1.2x10{sup 6} nodes. Comparisons of the computed results with measurements demonstrate the ability of the method to capture most experimental trends with reasonable accuracy. Calculated three-dimensional particle traces reveal very complex flow features in the vicinity of the piers, including horse-shoe longitudinal vortices and and regions of flow reversal.

  7. Studies on transport phenomena in polymer solutions and suspensions flowing through tubes of tortuous wall geometry

    Science.gov (United States)

    Narayanan, C. M.

    2014-02-01

    Attempts have been made to analyse the momentum and heat transfer characteristics in tortuous flow of non-Newtonian fluids such as suspensions and polymer solutions through tubes of diverging-converging geometry. The results of the study indicate that the transfer coefficients are significantly higher in such systems as compared to the conventional couette flow (through uniform cylindrical tubes). Moreover, the simultaneous increase in pressure drop due to the tortuous wall geometry has been observed to be relatively insignificant. Fluids with different rheological characteristics such as Bingham plastic fluids, pseudoplastic fluids, Ellis model fluids and fluids obeying Reiner-Philippoff rheology have been studied. The specific advantages of these geometries in providing enhanced performance efficiency have been effectively highlighted.

  8. Solidified structure of thin-walled titanium parts by vertical centrifugal casting

    Directory of Open Access Journals (Sweden)

    Wu Shiping

    2011-05-01

    Full Text Available The solidified structure of the thin-walled and complicated Ti-6Al-4V castings produced by the vertical centrifugal casting process was studied in the present work. The results show that the wall thickness of the section is featured with homogeneously distributed fine equiaxial grains, compared with the microstructure of the thick-walled section. The grain size of the castings has a tendency to decrease gradually with the increasing of the centrifugal radius. The inter-lamellar space in thick-walled casting parts is bigger than that of the thin-walled parts, and the profile of inter-lamellar space is not susceptible to the centrifugal radius.

  9. Development of an ECT technique for discriminating between a through-wall/non through-wall crack in a steam generator tube

    International Nuclear Information System (INIS)

    Lee, D.H.; Choi, M.S.; Hur, D.H.; Han, J.H.; Lee, U.C.

    2004-01-01

    In a lot of pressurized water reactors, PWSCC (primary water stress corrosion cracking) has been observed in the expansion or u-bend transitions of the alloy 600 steam generator tubes. Particularly, the development of a through-wall crack may cause leakage of the primary coolant during operation and the resultant forced outage, and the in-situ pressure test has often been used to evaluate the integrity and the leakage of the cracked tube during an in-service inspection. However, this process requires additional equipment and hours, and the tested tubes are plugged due to the plastic deformation induced by the internal pressurization. This paper describes a new evaluation technique of the Eddy current test, by which it can be determined whether the crack is through-wall or non through-wall. The technique is based upon the analysis of the characteristics in the Eddy current signals from the crack and also includes the method of measuring exact through-wall length of the crack. The proof and applicability of the technique is discussed with the results of the destructive tests on cracked tubes extracted from a commercial power plant. Also, the effect of crack opening, which reflects the driving force for a crack propagation of non through-wall crack and the leak rate of a through-wall crack, upon the characteristics of the Eddy current signals from the coils of the motorized rotating probe is investigated and discussed using steam generator tube samples with manufactured axial cracks of a through-wall and non through-wall. (orig.)

  10. Development of on-line wall thickness gauge for small size seamless tube. Shokei seamless netsukan nikuatsukei no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Okumura, T; Konya, N; Oka, H; Kasuya, T [Kawasaki Steel Corp., Tokyo (Japan)

    1991-03-01

    In order to heighten the accuracy of small size seamless tube wall thickness, hot wall thickness gauge was developed to be installed, immediately behind the finishing/rolling mill, for the on-line measurement, of which the method was by the parallel-beam transmissivity of gamma-ray. The measurement unit, aiming at flexible manufacturing system (FMS), is completely automated in correcting the accuracy, changing the sizes, etc. The damping characteristics of gamma-ray beam can be expressed by a characteristic function, taking the outside diameter and wall thickness of subject tube as parameters. The functional calculation, as based on measurement of transmitted quantity of gamma-ray through the three-dimensional steel material, changes, depending upon the outside diameter, wall thickness and material specification of subject tube. System was so applied as to calculate it therefore on a case-by-case basis. Though in the vicinity of tube end, the transmitted quantity of gamma-ray is largely influenced by the horizontal dislocation, that influence is slack in the middle part of tube. Therefore, the cross sectional division was made dense and sparse in the end part and middle part, respectively of tube, which division could diminish the error from several percent to less than 0.1%. The static noise was compressed by the optimized digital filter. That gauge is presently applied for the operational administration of small size seamless tube rolling. 2 refs., 11 figs., 2 tabs.

  11. Assessment of wall-thinning in carbon steel pipe by using laser-generated guided wave

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Yong; Cho, Youn Ho; Lee, Joon Hyun [Pusan National University, School of Mechanical Engineering, Busan (Korea, Republic of)

    2010-10-15

    The objective of this research is to estimate the crack location and size of a carbon steel pipe by using a laser ultrasound guided wave for the wall thinning evaluation of an elbow. The wall thinning of the carbon steel pipe is one of the most serious problems in nuclear power plants, especially the wall thinning of the carbon steel elbow caused by Flow-Accelerated Corrosion (FAC). Therefore, a non-destructive inspection method of elbow is essential for the nuclear power plants to operate safely. The specimens used in this study were carbon steel elbows, which represented the main elements of real nuclear power plants. The shape of the wall thinning was an oval with a width of 120mm, a length of 80mm, and a depth of 5mm. The L(0,1) and L(0,2) modes variation of the ultrasound guided wave signal is obtained from the response of the laser generation/air-coupled detection ultrasonic hybrid system represent the characteristics of the defect. The trends of these characteristics and signal processing were use dto estimate the size and location of wall thinning

  12. Assessment of wall-thinning in carbon steel pipe by using laser-generated guided wave

    International Nuclear Information System (INIS)

    Kim, Do Yong; Cho, Youn Ho; Lee, Joon Hyun

    2010-01-01

    The objective of this research is to estimate the crack location and size of a carbon steel pipe by using a laser ultrasound guided wave for the wall thinning evaluation of an elbow. The wall thinning of the carbon steel pipe is one of the most serious problems in nuclear power plants, especially the wall thinning of the carbon steel elbow caused by Flow-Accelerated Corrosion (FAC). Therefore, a non-destructive inspection method of elbow is essential for the nuclear power plants to operate safely. The specimens used in this study were carbon steel elbows, which represented the main elements of real nuclear power plants. The shape of the wall thinning was an oval with a width of 120mm, a length of 80mm, and a depth of 5mm. The L(0,1) and L(0,2) modes variation of the ultrasound guided wave signal is obtained from the response of the laser generation/air-coupled detection ultrasonic hybrid system represent the characteristics of the defect. The trends of these characteristics and signal processing were use dto estimate the size and location of wall thinning

  13. Vortical and acoustical mode coupling inside a porous tube with uniform wall suction.

    Science.gov (United States)

    Jankowskia, T A; Majdalani, J

    2005-06-01

    This paper considers the oscillatory motion of gases inside a long porous tube of the closed-open type. In particular, the focus is placed on describing an analytical solution for the internal acoustico-vortical coupling that arises in the presence of appreciable wall suction. This unsteady field is driven by longitudinal oscillatory waves that are triggered by small unavoidable fluctuations in the wall suction speed. Under the assumption of small amplitude oscillations, the time-dependent governing equations are linearized through a regular perturbation of the dependent variables. Further application of the Helmholtz vector decomposition theorem enables us to discriminate between acoustical and vortical equations. After solving the wave equation for the acoustical contribution, the boundary-driven vortical field is considered. The method of matched-asymptotic expansions is then used to obtain a closed-form solution for the unsteady momentum equation developing from flow decomposition. An exact series expansion is also derived and shown to coincide with the numerical solution for the problem. The numerically verified end results suggest that the asymptotic scheme is capable of providing a sufficiently accurate solution. This is due to the error associated with the matched-asymptotic expansion being smaller than the error introduced in the Navier-Stokes linearization. A basis for comparison is established by examining the evolution of the oscillatory field in both space and time. The corresponding boundary-layer behavior is also characterized over a range of oscillation frequencies and wall suction velocities. In general, the current solution is found to exhibit features that are consistent with the laminar theory of periodic flows. By comparison to the Sexl profile in nonporous tubes, the critically damped solution obtained here exhibits a slightly smaller overshoot and depth of penetration. These features may be attributed to the suction effect that tends to

  14. Nuclear Power Plants Secondary Circuit Piping Wall-Thinning Management in China

    International Nuclear Information System (INIS)

    Zhong Zhimin; Li Jinsong; Zheng Hui

    2012-01-01

    Research and field feedbacks showed that nuclear power plants secondary circuit steam and water piping are more sensitive than that of fuel plant to the attack of flow-accelerated corrosion (FAC). FAC, Liquid droplet impingement or cavitation erosion will cause secondary circuit piping local wall-thinning in NPPs. Without effective management, the wall-thinning in those high energy piping will cause leakage or pipe rupture during nuclear power plant operation, more seriously cause unplanned shut down, injured and fatality, or heavy economic losses. This paper briefly introduces the history, development and state of the art of secondary circuit piping wall-thinning management in China NPPs. Then, the effectiveness of inspection grid size selecting was analyzed in detail based on field feedbacks. EPRI recommendatory inspection grid, JSME code recommendatory grid and plant specific inspection grid were compared and the detection probabilities of local wall-thinning were estimated. Then, the development and application of NPPs Secondary Circuit Piping Wall Thickness Management Information System, developed, operated and maintained by our team, was briefly introduced and the statistical analysis results of 11 PWR units were shared. It was conclude that the long term, systemic, effective wall-thinning management strategy of high energy piping was very important to the safety and economic operation of NPPs. Furthermore, take into account the actual situation of China nuclear power plants, some advice and suggestion on developing effective nuclear power plant secondary circuit steam and water piping wall-thinning management system are put forward from code development, design and manufacture, operation management, pipeline and locations selection, inspection method selection and application, thickness measurement result evaluation, residual life predication and decision making, feedbacks usage, personnel training and etc. (author)

  15. Thermal fatigue crack growth on a thick wall tube containing a semi elliptical circumferential crack

    International Nuclear Information System (INIS)

    Deschanels, H.; Wakai, T.; Lacire, M.H.; Michel, B.

    2001-01-01

    In order to check the ability of the simplified assessment procedure (A16 guide) to predict fatigue crack growth, a benchmark problem was conducted. This work is carried out under the project ''agreement on the Exchange of Information and Collaboration in the field of Research and Development of Fast Breeder Reactor (FBR) between Europe (EU) and Japan''. Experimental work is conducted by PNC using Air cooled Thermal transient Test Facility (ATTF). Specimen is a thick wall tube containing a semi elliptical (3-D) circumferential crack and subjected to cyclic thermal transients. The constitutive material is the 304 austenitic stainless steel type SUS304. Due to thermal shock (650 C-300 C) the stress distribution through the wall is non-linear and well approximated using a 3 rd order polynomial. When comparing computations and tests data we observe a good agreement for the crack propagation in length. In crack depth, accurate results are obtained in the first part of the test, but on the later stage of the experiment the computations slightly underestimate the propagation (deep crack). In addition, we notice the importance of good evaluation of fracture mechanics parameters for non-linear stress distribution through the wall. At present A16 guide handbook gives stress intensity factor solutions for non-linear stress distribution through the wall. (author)

  16. Thin-walled nanoscrolls by multi-step intercalation from tubular halloysite-10 Å and its rearrangement upon peroxide treatment

    International Nuclear Information System (INIS)

    Zsirka, Balázs; Horváth, Erzsébet; Szabó, Péter; Juzsakova, Tatjána; Szilágyi, Róbert K.; Fertig, Dávid; Makó, Éva; Varga, Tamás

    2017-01-01

    Highlights: • Halloysite intercalation/delamination. • Thin-walled nanoscroll preparation. • Oxidative surface cleaning with H_2O_2 and heating. • X-ray diffraction, TEM, N_2 adsorption, TG/DTG and FT-IR/ATR measurements. • Nanoscroll rearrangement, periodicity along the crystallographic ‘c’-axis. - Abstract: Surface modification of the halloysite-10 Å mineral with tubular morphology can be achieved by slightly modified procedures developed for the delamination of kaolinite minerals. The resulting delaminated halloysite nanoparticles have unexpected surface/morphological properties that display, new potentials in catalyst development. In this work, a four-step intercalation/delamination procedure is described for the preparation of thin-walled nanoscrolls from the multi-layered hydrated halloysite mineral that consists of (1) intercalation of halloysite with potassium acetate, (2) replacement intercalation with ethylene glycol, (3) replacement intercalation with hexylamine, and (4) delamination with toluene. The intercalation steps were followed by X-ray diffraction, transmission electron microscopy, N_2 adsorption-desorption, thermogravimetry, and infrared spectroscopy. Delamination eliminated the crystalline order and the crystallite size along the ‘c’-axis, increased the specific surface area, greatly decreased the thickness of the mineral tubes to a monolayer, and shifted the pore diameter toward the micropore region. Unexpectedly, the removal of residual organics from intercalation steps adsorbed at the nanoscroll surface with a peroxide treatment resulted in partial recovery of crystallinity and increase of crystallite size along the ‘c’-crystal direction. The d(001) value showed a diffuse pattern at 7.4–7.7 Å due to the rearrangement of the thin-walled nanoscrolls toward the initial tubular morphology of the dehydrated halloysite-7 Å mineral.

  17. Thin-walled nanoscrolls by multi-step intercalation from tubular halloysite-10 Å and its rearrangement upon peroxide treatment

    Energy Technology Data Exchange (ETDEWEB)

    Zsirka, Balázs, E-mail: zsirkab@almos.vein.hu [University of Pannonia, Institute of Environmental Engineering, P.O. Box 158, Veszprém 8201 Hungary (Hungary); Horváth, Erzsébet, E-mail: erzsebet.horvath@gmail.com [University of Pannonia, Institute of Environmental Engineering, P.O. Box 158, Veszprém 8201 Hungary (Hungary); Szabó, Péter, E-mail: xysma@msn.com [University of Pannonia, Department of Analytical Chemistry, P.O. Box 158, Veszprém 8201 Hungary (Hungary); Juzsakova, Tatjána, E-mail: yuzhakova@almos.uni-pannon.hu [University of Pannonia, Institute of Environmental Engineering, P.O. Box 158, Veszprém 8201 Hungary (Hungary); Szilágyi, Róbert K., E-mail: szilagyi@montana.edu [Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717 (United States); Fertig, Dávid, E-mail: fertig.david92@gmail.com [University of Pannonia, Department of Analytical Chemistry, P.O. Box 158, Veszprém 8201 Hungary (Hungary); Makó, Éva, E-mail: makoe@almos.vein.hu [University of Pannonia, Institute of Materials Engineering, P.O. Box 158, Veszprém 8201 Hungary (Hungary); Varga, Tamás, E-mail: vtamas@chem.u-szeged.hu [University of Szeged, Department of Applied and Environmental Chemistry, Rerrich B. tér 1., Szeged H-6720 Hungary (Hungary); and others

    2017-03-31

    Highlights: • Halloysite intercalation/delamination. • Thin-walled nanoscroll preparation. • Oxidative surface cleaning with H{sub 2}O{sub 2} and heating. • X-ray diffraction, TEM, N{sub 2} adsorption, TG/DTG and FT-IR/ATR measurements. • Nanoscroll rearrangement, periodicity along the crystallographic ‘c’-axis. - Abstract: Surface modification of the halloysite-10 Å mineral with tubular morphology can be achieved by slightly modified procedures developed for the delamination of kaolinite minerals. The resulting delaminated halloysite nanoparticles have unexpected surface/morphological properties that display, new potentials in catalyst development. In this work, a four-step intercalation/delamination procedure is described for the preparation of thin-walled nanoscrolls from the multi-layered hydrated halloysite mineral that consists of (1) intercalation of halloysite with potassium acetate, (2) replacement intercalation with ethylene glycol, (3) replacement intercalation with hexylamine, and (4) delamination with toluene. The intercalation steps were followed by X-ray diffraction, transmission electron microscopy, N{sub 2} adsorption-desorption, thermogravimetry, and infrared spectroscopy. Delamination eliminated the crystalline order and the crystallite size along the ‘c’-axis, increased the specific surface area, greatly decreased the thickness of the mineral tubes to a monolayer, and shifted the pore diameter toward the micropore region. Unexpectedly, the removal of residual organics from intercalation steps adsorbed at the nanoscroll surface with a peroxide treatment resulted in partial recovery of crystallinity and increase of crystallite size along the ‘c’-crystal direction. The d(001) value showed a diffuse pattern at 7.4–7.7 Å due to the rearrangement of the thin-walled nanoscrolls toward the initial tubular morphology of the dehydrated halloysite-7 Å mineral.

  18. Vibration improved the fluidity of aluminum alloys in thin wall ...

    African Journals Online (AJOL)

    user

    The technique to "increase" the metal head during casting and improve the ... The effect of vibration is quantified and incorporated into the fluidity model, such that the ..... Deformation, caused by the expansion and contraction of the thin skin of ...

  19. Nondestructive evaluation of wall thinning occurred under reinforced plate by MFL method

    International Nuclear Information System (INIS)

    Kikuchi, Hiroaki; Sato, Kaito; Shimizu, Isamu

    2013-01-01

    Basic study on applying magnetic flux leakage (MFL) method using ac excitation to a nondestructive evaluation of wall thinning occurred under reinforcing plates in nuclear power plants were performed. Frequently, MFL method by means of dc field for exciting specimens is adopted, and only intensity of magnetic flux density is evaluated. On the other hand, MFL with alternating current enable us to utilize not only amplitude of magnetic flux density but also phase difference, which contributes to evaluation with higher accuracy. Here, specimens with slit and pipe with imitated wall thinning are prepared and magnetized using magnetic yoke with ac field, and then the leakage magnetic flux density and the phase difference on the specimen surface are investigated. Additionally, specimens imitated wall thinning occurred under reinforcing plates were investigated by MFL with ac excitation. (author)

  20. A new local thickening reverse spiral origami thin-wall construction for improving of energy absorption

    Science.gov (United States)

    Kong, C. H.; Zhao, X. L.; Hagiwara, I. R.

    2018-02-01

    As an effective and representative origami structure, reverse spiral origami structure can be capable to effectively take up energy in a crash test. The origami structure has origami creases thus this can guide the deformation of structure and avoid of Euler buckling. Even so the origami creases also weaken the support force and this may cut the absorption of crash energy. In order to increase the supporting capacity of the reverse spiral origami structure, we projected a new local thickening reverse spiral origami thin-wall construction. The reverse spiral origami thin-wall structure with thickening areas distributed along the longitudinal origami crease has a higher energy absorption capacity than the ordinary reverse spiral origami thin-wall structure.

  1. The method to design the length of thin-wall flexible rotor

    International Nuclear Information System (INIS)

    Zhang Yue; Yao Zengzhong; Baigu Lafu

    2014-01-01

    Thin-wall flexible rotor is frequently used in rotating machinery. For this rotor the vibration is very complex under the working speed. So the composition design is very difficult. In this paper, for a thin-wall flexible rotor, the material and rotor diameter are determined from spatial structure, the working speed is determined from strength of the material, the first bending critical speed is determined from working speed, then the influence of length on the critical speed is researched. According to the influence of critical speed on the vibration, the length design method is researched, the design steps and methods are given, the safety margin of vibration is analysed. Design validity is established by test. The method is generally suitable for thin-wall flexible rotor. (authors)

  2. Online monitoring of pipe wall thinning by electromagnetic acoustic resonance method

    International Nuclear Information System (INIS)

    Urayama, Ryoichi; Takagi, Toshiyuki; Uchimoto, Tetsuya; Kanemoto, Shigeru

    2013-01-01

    The electromagnetic acoustic resonance (EMAR) method provides accurate and stable evaluation in high temperature environment, and it is an effective tool for online monitoring. In this study, the EMAR method and the superposition of the n-th compression (SNC) for data processing are applied to online monitoring of pipe wall thinning, and the accuracy and reliability of the measurements are demonstrated through field tests using a large-scale corrosion test loop at high temperature. To measure the thickness of pipes with complicated wall thinning, the SNC extracts thickness information from the spectral responses of the EMAR. Results from monitoring test show that EMAR with SNC can evaluate pipe wall thinning with an accuracy of 10 μm at 165degC. In addition, time evaluation of evaluated thickness decreases monotonically all over the test duration, which indicates high stability of this measurement technique. (author)

  3. Graphite nodule count and size distribution in thin-walled ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2008-01-01

    Graphite nodule count and size distribution have been analysed in thin walled ductile cast iron. The 2D nodule counts have been converted into 3D nodule count by using Finite Difference Method (FDM). Particles having a diameter smaller than 5 µm should be neglected in the nodule count as these ar......Graphite nodule count and size distribution have been analysed in thin walled ductile cast iron. The 2D nodule counts have been converted into 3D nodule count by using Finite Difference Method (FDM). Particles having a diameter smaller than 5 µm should be neglected in the nodule count...... as these are inclusions and micro porosities that do not influence the solidification morphology. If there are many small graphite nodules as in thin walled castings only 3D nodule count calculated by FDM will give reliable results. 2D nodule count and 3D nodule count calculated by simple equations will give too low...

  4. Strong, corrosion-resistant aluminum tubing

    Science.gov (United States)

    Reed, M. W.; Adams, F. F.

    1980-01-01

    When aluminum tubing having good corrosion resistance and postweld strength is needed, type 5083 alloy should be considered. Chemical composition is carefully controlled and can be drawn into thin-wall tubing with excellent mechanical properties. Uses of tubing are in aircraft, boats, docks, and process equipment.

  5. Deposition of thin ultrafiltration membranes on commercial SiC microfiltration tubes

    DEFF Research Database (Denmark)

    Facciotti, Marco; Boffa, Vittorio; Magnacca, Giuliana

    2014-01-01

    Porous SiC based materials present high mechanical, chemical and thermal robustness, and thus have been largely applied to water-filtration technologies. In this study, commercial SiC microfiltration tubes with nominal pore size of 0.04 m were used as carrier for depositing thin aluminium oxide....... After 5 times coating, a 5.6 µm thick γ-Al2O3 layer was obtained. This membrane shows retention of ~75% for polyethylene glycol molecules with Mn of 8 and 35 kDa, indicating that, despite their intrinsic surface roughness, commercial SiC microfiltration tubes can be applied as carrier for thin...... ultrafiltration membranes. This work also indicates that an improvement of the commercial SiC support surface smoothness may greatly enhance permeance and selectivity of Υ-Al2O3 ultrafiltration membranes by allowing the deposition of thinner defect-free layers....

  6. Thin-walled nanoscrolls by multi-step intercalation from tubular halloysite-10 Å and its rearrangement upon peroxide treatment

    Science.gov (United States)

    Zsirka, Balázs; Horváth, Erzsébet; Szabó, Péter; Juzsakova, Tatjána; Szilágyi, Róbert K.; Fertig, Dávid; Makó, Éva; Varga, Tamás; Kónya, Zoltán; Kukovecz, Ákos; Kristóf, János

    2017-03-01

    Surface modification of the halloysite-10 Å mineral with tubular morphology can be achieved by slightly modified procedures developed for the delamination of kaolinite minerals. The resulting delaminated halloysite nanoparticles have unexpected surface/morphological properties that display, new potentials in catalyst development. In this work, a four-step intercalation/delamination procedure is described for the preparation of thin-walled nanoscrolls from the multi-layered hydrated halloysite mineral that consists of (1) intercalation of halloysite with potassium acetate, (2) replacement intercalation with ethylene glycol, (3) replacement intercalation with hexylamine, and (4) delamination with toluene. The intercalation steps were followed by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption, thermogravimetry, and infrared spectroscopy. Delamination eliminated the crystalline order and the crystallite size along the 'c'-axis, increased the specific surface area, greatly decreased the thickness of the mineral tubes to a monolayer, and shifted the pore diameter toward the micropore region. Unexpectedly, the removal of residual organics from intercalation steps adsorbed at the nanoscroll surface with a peroxide treatment resulted in partial recovery of crystallinity and increase of crystallite size along the 'c'-crystal direction. The d(001) value showed a diffuse pattern at 7.4-7.7 Å due to the rearrangement of the thin-walled nanoscrolls toward the initial tubular morphology of the dehydrated halloysite-7 Å mineral.

  7. Evaluation of advanced automatic PET segmentation methods using nonspherical thin-wall inserts

    International Nuclear Information System (INIS)

    Berthon, B.; Marshall, C.; Evans, M.; Spezi, E.

    2014-01-01

    Purpose: The use of positron emission tomography (PET) within radiotherapy treatment planning requires the availability of reliable and accurate segmentation tools. PET automatic segmentation (PET-AS) methods have been recommended for the delineation of tumors, but there is still a lack of thorough validation and cross-comparison of such methods using clinically relevant data. In particular, studies validating PET segmentation tools mainly use phantoms with thick plastic walls inserts of simple spherical geometry and have not specifically investigated the effect of the target object geometry on the delineation accuracy. Our work therefore aimed at generating clinically realistic data using nonspherical thin-wall plastic inserts, for the evaluation and comparison of a set of eight promising PET-AS approaches. Methods: Sixteen nonspherical inserts were manufactured with a plastic wall of 0.18 mm and scanned within a custom plastic phantom. These included ellipsoids and toroids derived with different volumes, as well as tubes, pear- and drop-shaped inserts with different aspect ratios. A set of six spheres of volumes ranging from 0.5 to 102 ml was used for a baseline study. A selection of eight PET-AS methods, written in house, was applied to the images obtained. The methods represented promising segmentation approaches such as adaptive iterative thresholding, region-growing, clustering and gradient-based schemes. The delineation accuracy was measured in terms of overlap with the computed tomography reference contour, using the dice similarity coefficient (DSC), and error in dimensions. Results: The delineation accuracy was lower for nonspherical inserts than for spheres of the same volume in 88% cases. Slice-by-slice gradient-based methods, showed particularly lower DSC for tori (DSC 0.76 except for tori) but showed the largest errors in the recovery of pears and drops dimensions (higher than 10% and 30% of the true length, respectively). Large errors were visible

  8. Macroscopic and microscopic determinations of residual stresses in thin oxide dispersion strengthened steel tubes

    International Nuclear Information System (INIS)

    Bechade, J.L.; Toualbi, L.; Bosonnet, S.; Carlan, Y. de; Castelnau, O.

    2014-01-01

    To improve the efficiency of components operating at high temperatures, many efforts are deployed to develop new materials. Oxide Dispersion Strengthened (ODS) materials could be used for heat exchangers or cladding tubes for the new GENIV nuclear reactors. This type of materials are composed with a metallic matrix (usually iron base alloy for nuclear applications or nickel base alloy for heat exchangers) reinforced by a distribution of nano-oxides. They are obtained by powder metallurgy and mechanical alloying. The creep resistance of these materials is excellent, and they usually exhibit a high tensile strength at room temperature. Depending on the cold working and/or the heat treatments, several types of microstructure can be obtained: recrystallised, stress relieved. One of the key challenges is to transform ODS materials into thin tubes (up to 500 microns thick) within a robust fabrication route while keeping the excellent mechanical properties. To prevent cracking during the process or to obtain a final product with low residual stresses, it is important to quantify the effect of the heat treatments on the release of internal stresses. The aim of this study is to show how residual stresses can be determined on different thin tubes using two complementary approaches: (i) macroscopic stresses determination in the tube using beam theory (small cuts along the longitudinal and circumferential directions and measurements of the deflection), (ii) stress determination from x-ray diffraction analyses (surface analyses, using 'sin"2ψ' method with different hypothesis). Depending on the material and the heat treatment, residual stresses vary dramatically and can reach 800 MPa which is not far from the yield stress; comparisons between both methods are performed and suggestions are given in order to optimize the thermo-mechanical treatment of thin ODS tubes. (authors)

  9. Development of wall thinning screening system and its application to a commercial nuclear power plant

    International Nuclear Information System (INIS)

    Ryu, Kyung Ha; Hwang, Il Soon; Kim, Ji Hyun

    2013-01-01

    Highlights: • Wall loss screening system (WalSS) has been developed based on ES-DCPD method. • Screening criteria was established based on the thinning of the actual shape that occur in the power plant. • With the criteria, the WalSS gives priority of the need for inspection. • This technique was successfully applied to commercial nuclear power plant. - Abstract: A new non-destructive evaluation (NDE) method has been developed for metal pipes for the detection wall thinning. The method has been showed to be suitable for applications to electric power generation plants where flow accelerated corrosion (FAC) of carbon steel piping is a significant cause of increased maintenance and plant personnel casualty. The wall thinning screening system (WalSS) was developed in two major phases. In the first phase, the equipotential switching direct current potential drop (ES-DCPD) method was developed for piping wall (Ryu et al., 2008a, 2010). In the second phase, in this paper, a quantitative detection criteria was developed. The relative ES-DCPD change of 3.8% has been defined as the screening criteria for wall thinning schematization. This criteria means that the component with measured ES-DCPD change greater than 3.8% is called for a more comprehensive examination. In the criteria development, all variables were taken into consideration based on commercial plant piping inspection data such as initial thickness distributions, wall thinning shape and nominal thickness. The developed WalSS based on ES-DCPD was applied to a moisture separator reheater (MSR) drain line of a commercial nuclear power plant (NPP) during a scheduled overhaul. The measured ES-DCPD change was 2.16%, which is lower than the ES-DCPD criteria, identifying the pipe having adequate wall thickness. This is confirmed by site thickness inspection using ultrasonic technique (UT)

  10. Fabrication technology for a series of cylindrical thin-wall cavity targets

    CERN Document Server

    Zheng Yong; Sun Zu Oke; Wang Ming Da; Zhou La; Zhou Zhi Yun

    2002-01-01

    Cylindrical thin-wall cavity targets have been fabricated to study the behavior of superthermal electrons and their effects on inertial confinement fusion (ICF). Self-supporting cavity targets having adjustable, uniform wall thickness, and low surface roughness were required. This required production of high-quality mandrels, coating them by sputtering or electroplating, developing techniques for measurement of wall thickness and other cavity parameters, improving the uniformity of rotation of the mandrels, and preventing damage to the targets during removal from the mandrels. Details of the fabrication process are presented. Experimental results from the use of these targets are presented. These results, in good agreement with simulations, indicate that the use of thin-wall cavity targets is an effective method for studying superthermal electrons in ICF.

  11. Method of fabricating thin-walled articles of tungsten-nickel-iron alloy

    Science.gov (United States)

    Hovis, Jr., Victor M.; Northcutt, Jr., Walter G.

    1982-01-01

    The present invention relates to a method for fabricating thin-walled high-density structures oftungsten-nickel-iron alloys. A powdered blend of the selected alloy constituents is plasma sprayed onto a mandrel having the desired article configuration. The sprayed deposit is removed from the mandrel and subjected to liquid phase sintering to provide the alloyed structure. The formation of the thin-walled structure by plasma spraying significantly reduces shrinkage, and cracking while increasing physical properties of the structure over that obtainable by employing previously known powder metallurgical procedures.

  12. Vibrational behavior of adaptive aircraft wing structures modelled as composite thin-walled beams

    Science.gov (United States)

    Song, O.; Librescu, L.; Rogers, C. A.

    1992-01-01

    The vibrational behavior of cantilevered aircraft wings modeled as thin-walled beams and incorporating piezoelectric effects is studied. Based on the converse piezoelectric effect, the system of piezoelectric actuators conveniently located on the wing yield the control of its associated vertical and lateral bending eigenfrequencies. The possibility revealed by this study enabling one to increase adaptively the eigenfrequencies of thin-walled cantilevered beams could play a significant role in the control of the dynamic response and flutter of wing and rotor blade structures.

  13. Temperature measurement during solidification of thin wall ductile cast iron. Part 1: Theory and experiment

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2008-01-01

    cooing curves in thin wall ductile iron castings. The experiments show how TC’s of different design interact with the melt and how TC design and surface quality affect the results of the data acquisition. It is discussed which precautions should be taken to ensure reliable acquisition of cooling curves....... Measurement error depending on TC design and cooling conditions is shown. A method is presented that allows acquisition of cooling curves in thin walled ductile iron castings down to thickness of at least 2.8 mm. The obtained cooling curves can be used to compare nucleation and growth during solidification...

  14. Probabilistic methods for evaluation of erosion-corrosion wall thinning in french pressurized water reactors

    International Nuclear Information System (INIS)

    Ardillon, E.; Bouchacourt, M.

    1994-04-01

    This paper describes the application of the probabilistic approach to a selected study section having known characteristics. The method is based on the physico-chemical model of erosion-corrosion, the variables of which are probabilized. The three main aspects of the model, namely the thermohydraulic flow conditions, the chemistry of the fluid, and the geometry of the installation, are described. The study ultimately makes it possible determine: - the evolution of wall thinning distribution, using the power station's measurements; - the main parameters of influence on the kinetics of wall thinning; - the evolution of the fracture probabilistic of the pipe in question. (authors). 10 figs., 7 refs

  15. Development of NDT simulator with method of mapping for detection of pipe wall thinning using EMAT

    International Nuclear Information System (INIS)

    Yamaguchi, Hiroshi; Kojima, Fumio; Kosaka, Daigo

    2009-01-01

    This paper is concerned with a simulator related to nondestructive test using Electromagnetic Acoustic Transducer (EMAT). The simulator developed here can be applied to pipe wall thinning of stainless steel used in nuclear power plants. First, mathematical models for the inspection are given by a transient eddy current equation and by a time dependent elastic wave equation in two dimensions. Secondly, shape of pipe wall thinning is modeled by B-spline function and is applied to the mathematical models using method of mapping. Finally, the validity of the proposed simulator is shown through numerical experiment. (author)

  16. High-pressure oxygenation of thin-wall YBCO single-domain samples

    International Nuclear Information System (INIS)

    Chaud, X; Savchuk, Y; Sergienko, N; Prikhna, T; Diko, P

    2008-01-01

    The oxygen annealing of ReBCO bulk material, necessary to achieve superconducting properties, usually induces micro- and macro-cracks. This leads to a crack-assisted oxygenation process that allows oxygenating large bulk samples faster than single crystals. But excellent superconducting properties are cancelled by the poor mechanical ones. More progressive oxygenation strategy has been shown to reduce drastically the oxygenation cracks. The problem then arises to keep a reasonable annealing time. The concept of bulk Y123 single-domain samples with thin-wall geometry has been introduced to bypass the inherent limitation due to a slow oxygen diffusion rate. But it is not enough. The use of a high oxygen pressure (16 MPa) enables to speed up further the process. It introduces a displacement in the equilibrium phase diagram towards higher temperatures, i.e., higher diffusion rates, to achieve a given oxygen content in the material. Remarkable results were obtained by applying such a high pressure oxygen annealing process on thin-wall single-domain samples. The trapped field of 16 mm diameter Y123 thin-wall single-domain samples was doubled (0.6T vs 0.3T at 77K) using an annealing time twice shorter (about 3 days). The initial development was made on thin bars. The advantage of thin-wall geometry is that such an annealing can be applied directly to a much larger sample

  17. Development of a guided wave simulator and its application to monitoring of pipe wall thinning

    International Nuclear Information System (INIS)

    Furukawa, Akinori; Kojima, Fumio

    2009-01-01

    Motivated by growing demand for quantitative nondestructive evaluation of pipe wall thinning, the aim of this paper is to develop a simulator for guided wave analysis. First, an inspection system can be represented by a linear elastic system in cylindrical coordinates. Secondly a dynamical numerical scheme for wave propagation on a pipe wall is proposed based on Fourier-Galerkin approach. Finally, the effectiveness and validity of the proposed method are shown in computational experiments. (author)

  18. Behavior of Hollow Thin Welded Tubes Filled with Sand Slag Concrete

    Directory of Open Access Journals (Sweden)

    Noureddine Ferhoune

    2016-01-01

    Full Text Available This paper presents the axial bearing capacity of thin welded rectangular steel stubs filled with concrete sand. A series of tests was conducted to study the behavior of short composite columns under axial compressive load; the cross section dimensions were 100 × 70 × 2 mm. A total of 20 stubs have been tested, as follows: 4 hollow thin welded tubes were tested to axial and eccentric load compression, 4 were filled with ordinary concrete appointed by BO columns, 6 were filled with concrete whose natural sand was completely substituted by a crystallized sand slag designated in this paper by BSI, and 6 were tucked in concrete whose natural sand was partially replaced by a crystallized sand slag called BSII. The main parameters studied are the height of the specimen (300 mm–500 mm, eccentricity of load and type of filling concrete. Based on test results obtained, it is confirmed that the length of the tubes has a considerable effect on the bearing capacity and the failure mode. In all test tubes, fracture occurred by the convex local buckling of steel section due to the outward thrust of the concrete; it was observed that the sand concrete improves the bearing capacity of tubes compounds compared to those filled with ordinary concrete.

  19. Simultaneous and long-lasting hydrophilization of inner and outer wall surfaces of polytetrafluoroethylene tubes by transferring atmospheric pressure plasmas

    International Nuclear Information System (INIS)

    Chen, Faze; Song, Jinlong; Huang, Shuai; Xu, Wenji; Sun, Jing; Liu, Xin; Xu, Sihao; Xia, Guangqing; Yang, Dezheng

    2016-01-01

    Plasma hydrophilization is a general method to increase the surface free energy of materials. However, only a few works about plasma modification focus on the hydrophilization of tube inner and outer walls. In this paper, we realize simultaneous and long-lasting plasma hydrophilization on the inner and outer walls of polytetrafluoroethylene (PTFE) tubes by atmospheric pressure plasmas (APPs). Specifically, an Ar atmospheric pressure plasma jet (APPJ) is used to modify the PTFE tube’s outer wall and meanwhile to induce transferred He APP inside the PTFE tube to modify its inner wall surface. The optical emission spectrum (OES) shows that the plasmas contain many chemically active species, which are known as enablers for various applications. Water contact angle (WCA) measurements, x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) are used to characterize the plasma hydrophilization. Results demonstrate that the wettability of the tube walls are well improved due to the replacement of the surface fluorine by oxygen and the change of surface roughness. The obtained hydrophilicity decreases slowly during more than 180 d aging, indicating a long-lasting hydrophilization. The results presented here clearly demonstrate the great potential of transferring APPs for surface modification of the tube’s inner and outer walls simultaneously. (paper)

  20. The effect of load-controlled bending load on the failure pressure of wall-thinned pipe elbows

    International Nuclear Information System (INIS)

    Kim, Jin Weon; Yoon, Min Soo; Park, Chi Yong

    2013-01-01

    Highlights: • We evaluated bending load effect on the failure pressure of wall-thinned pipe elbows. • Burst tests were conducted on real-scale elbow specimens with local wall thinning. • The tests were performed under combined pressure and load-controlled bending. • Load-controlled bending reduced the failure pressure of wall-thinned elbows. • Bending load effect was significant for opening-mode and intrados wall-thinning case. - Abstract: In this research, burst tests were conducted on real-scale elbow specimens, each with an artificial local wall-thinning defect, under combined internal pressure and constant in-plane bending load, as well as under simple internal pressure, to evaluate the effect of load-controlled bending load on the failure pressure of locally wall-thinned pipe elbows. Ninety-degree, 65A Schedule 80 elbows, with wall-thinning defects in the intrados and extrados, were used as specimens. The bending loads were in-plane opening- and closing-mode bending, applied in load-control mode. The results clearly indicated that a load-controlled in-plane bending load reduced the failure pressure of wall-thinned pipe elbows, in contrast to observations previously made under displacement-controlled bending conditions. The effect of the bending load was more significant for opening-mode than for closing-mode bending, regardless of the wall-thinning location in the elbow. Also, the effect was greater when the wall-thinning defect was located in the intrados region of the elbow, rather than the extrados region. Existing models that have been proposed to evaluate the failure of wall-thinned elbows under simple internal pressure conservatively predicted the failure pressure of elbows subjected to a combined internal pressure and load-controlled bending load

  1. A consideration on pipe-wall thinning mechanisms from an aspect of fluid-mechanics

    International Nuclear Information System (INIS)

    Inada, Fumio; Yoneda, Kimitoshi; Morita, Ryo; Fujiwara, Kazutoshi; Furuya, Masahiro

    2008-01-01

    The contribution of the fluid mechanics to the piping wall thinning phenomena was investigated. It was shown that the fluid force to the wall was quite different between flow accelerated corrosion (FAC) and erosion. The turbulent mass transfer, which is one of the primary factors of FAC, was analogous to the turbulent heat transfer. The model that the molecular transport in the viscous sublayer nearby soon of wall was predominant was practicable. In addition, the mass transport was predicted using commercial codes of computational fluid dynamics. Some prediction results of the mass transfer in orifice and the elbow using above techniques were explained. (author)

  2. Electrophoretic deposition (EPD) of multi-walled carbon nano tubes (MWCNT) onto indium-tin-oxide (ITO) glass substrates

    International Nuclear Information System (INIS)

    Mohd Roslie Ali; Shahrul Nizam Mohd Salleh

    2009-01-01

    Full text: Multi-Walled Carbon Nano tubes (MWCNT) were deposited onto Indium-Tin-Oxide (ITO)-coated glass substrates by introducing the use of Electrophoretic Deposition (EPD) as the method. The Multi-Walled Carbon Nano tubes (MWCNT) were dispersed ultrasonically in ethanol and sodium hydroxide (NaOH) to form stable suspension. The addition of Sodium Hydroxide in ethanol can stabilize the suspension, which was very important step before the deposition take place. Two substrates of Indium-Tin-Oxide(ITO)-coated glass placed in parallel facing each other (conductive side) into the suspension. The deposition occurs at room temperature, which the distance fixed at 1 cm between both electrodes and the voltage level applied was fixed at 400 V, respectively. The deposition time also was fixed at 30 minutes. The deposited ITO-Glass with Multi-Walled Carbon Nano tubes (MWCNT) will be characterized using Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM), and Raman Microscope. The images of SEM shows that the Multi -Walled Carbon Nano tubes (MWCNT) were distributed uniformly onto the surface of ITO-Glass. The deposited ITO-Glass with Multi-Walled Carbon Nano tubes (MWCNT) could be the potential material in various practical applications such as field emission devices, fuel cells, and super capacitors. Electrophoretic deposition (EPD) technique was found to be an efficient technique in forming well distribution of Multi-Walled Carbon Nano tubes (MWCNT) onto ITO-Glass substrates, as proved in characterization methods, in which the optimum conditions will play the major role. (author)

  3. Study on structural integrity of thinned wall piping against seismic loading-overview and future program

    International Nuclear Information System (INIS)

    Nakamura, Izumi; Otani, Akihito; Shiratori, Masaki

    2005-01-01

    In order to clarify the behavior of thinned wall pipes under seismic events, cyclic in-plane and/or out-of-plane bending tests on thinned straight pipe and elbow and also shaking table tests using degraded piping system models were conducted. Relation between the failure mode and thinned condition and the influence of the final failure mode of degraded piping systems were investigated. In addition to these experiments, elastic-plastic FEM analysis using ABAQUS were conducted on thinned piping elements. It has been found that the strain concentrated point could be predicted and the cause of its generation could be explained by the simulated deformation behavior of the pipe. In order to predict the piping system's maximum response under elastic-plastic response, a simple response prediction method was proposed. Further tests and safety margin analyses of thinned pipes against seismic loading will be performed. (T. Tanaka)

  4. Guide tube sleeve

    International Nuclear Information System (INIS)

    Attix, D.J.

    1983-01-01

    The invention increases the operating capacity of a nuclear reactor by causing a modification in the flow pattern of the coolant which enhances the coolant's effectiveness. The apparatus provides a thin-walled tubular sleeve closely surrounding but not attached to the exterior surface of a guide tube in a fuel assembly. The wall of the sleeve has tabs projecting outwardly into adjacent flow channels. The sleeve is attached to the wall of a cellular void through which passes the guide tube associated with said sleeve. The tabs increase the flow of water in the channel and thus increase the heat transfer

  5. Study of Local and Distortional Stability of Thin-Walled Structures

    Directory of Open Access Journals (Sweden)

    Imene Mahi

    2018-01-01

    Full Text Available Thin-walled structures have an increasingly large and growing field of application in the engineering sector, the goal behind using this type of structure is efficiency in terms of resistance and cost, however the stability of its components (the thin walls remains the first aspect of the behavior, and a primordial factor in the design process. The hot rolled sections are known by a consequent post-buckling reserve, cold-formed steel sections which are thin-walled elements also benefit, in this case, it seems essential to take into account the favorable effects of this reserve in to the verification procedure of the resistance with respect to the three modes of failures of this type of structure. The design method that takes into account this reserve of resistance is inevitably the effective width method. The direct strength method has been developed to improve the speed and efficiency of the design of thin-walled profiles. The latter mainly uses the buckling loads (for Local, Distortional and Global mode obtained from a numerical analysis and the resistance curves calibrated experimentally to predict the ultimate load of the profile. Among those, the behavior of a set of Cshaped profiles (highly industrialized is studied, this type of section is assumed to be very prone to modes of local and distortional instability. The outcome of this investigation revealed very relevant conclusions both scientifically and practically.

  6. Temperature measurement during solidification of thin wall ductile cast iron. Part 2: Numerical simulations

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2008-01-01

    Temperature measurements in castings are carried out with thermocouples (TC’s), which are inserted in the melt. The TC influence solidification of the casting, especially in thin wall castings where the heat content of the melt is small compared to the cooling power of the TC. A numerical analysi...

  7. Nucleation and solidification of thin walled ductile iron - Experiments and numerical simulation

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2005-01-01

    Investigation of solidification of thin walled ductile cast iron has been performed based on experiments and numerical simulation. The experiments were based on temperature and microstructure examination. Results of the experiments have been compared with a 1-D numerical solidification model...

  8. Numerical modelling of thin-walled hypereutectic ductile cast iron parts

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Hattel, Jesper Henri; Tiedje, Niels Skat

    2006-01-01

    Solidification of hypereutectic thin-walled ductile cast iron has been modelled in one dimension taking into account the precipitation of off-eutectic austenite dendrites during solidification. The simulations have been compared with casting experiments on plate geometries with plate thicknesses...

  9. Stress state of thinwalled member of the structure with operation damages under nonuniform loading

    Directory of Open Access Journals (Sweden)

    В.В. Астанін

    2004-01-01

    Full Text Available  The publication is dedicated to determining of stress state in particular the stress concentration factors for thinwalled members of the structures subject to nonuniform tension. A structure member has obtained the operation damage generation by corrosion and other causes.

  10. Development of engineering program for integrity evaluation of pipes with local wall thinned defects

    International Nuclear Information System (INIS)

    Park, Chi Yong; Lee, Sung Ho; Kim, Tae Ryong; Park, Sang Kyu

    2008-01-01

    Integrity evaluation of pipes with local wall thinning by erosion and corrosion is increasingly important in maintenance of wall thinned carbon steel pipes in nuclear power plants. Though a few program for integrity assessment of wall thinned pipes have been developed in domestic nuclear field, however those are limited to straight pipes and methodology proposed in ASME Sec.XI Code Case N-597. Recently, the engineering program for integrity evaluation of pipes with all kinds of local wall defects such as straight, elbow, reducer and branch pipes was developed successfully. The program was designated as PiTEP (Pipe Thinning Evaluation Program), which name was registered as a trademark in the Korea Intellectual Property Office. A developed program is carried out by sequential step of four integrity evaluation methodologies, which are composed of construction code, code case N-597, its engineering method and two developed owner evaluation method. As PiTEP program will be performed through GUI (Graphic User Interface) with user's familiarity, it would be conveniently used by plant engineers with only measured thickness data, basic operation conditions and pipe data

  11. Thick-walled anisotropic elliptic tube analyzed via curvilinear tensor calculus

    Directory of Open Access Journals (Sweden)

    Mareš T.

    2007-10-01

    Full Text Available After a brief introduction into the tensor calculus, the thick-walled anisotropic elliptic tube is analyzed. A procedure of the analysis is described in a stepwise manner. A choice of the appropriate coordinate systems is the first step. The second step consists of the determination of corresponding metric tensors. Then the elasticity tensor of a local orthotropy is transformed into a global computational coordinate system. Next the appropriate Christoffel symbols of the second kind are determined and the total potential energy of the system is expressed. At the end the solution is approximated by a Fourier series and for given geometrical values and loading the numerical results are obtained and graphically represented.It must be said that throughout the calculation the free software only was used and for the numerical operations an old laptop is sufficient. The author regards both the former and the latter as a great advantage of the demonstrated method.

  12. Nonlinear free vibration of single walled Carbone NanoTubes conveying fluid

    Directory of Open Access Journals (Sweden)

    Azrar A.

    2014-04-01

    Full Text Available Nonlinear free vibration of single-walled carbon nanotubes (CNTs conveying fluid are modeled and numerically simulated based on von Kármán geometric nonlinearity and Eringen’s nonlocal elasticity theory. The CNTs are modelled as nanobeams where the effects of transverse shear deformation and rotary inertia are considered within the framework of Timoshenko beam theory. The governing equations and boundary conditions are derived using the Hamilton’s principle and the nonlinear equation of motion is solved by the Galerkin’s method. The small scale parameter and the fluid-tube interaction effects on the dynamic behaviours of the CNT-fluid system as well as the instabilities induced by the fluid-velocity can be investigated. The critical fluid-velocity and frequency-amplitude relationships as well as the flutter and divergence instability types and the associated time responses are obtained based on the presented methodological approach.

  13. Hydrogen adsorption in microporous alkali-doped carbons (single-wall carbon nano-tubes and activated carbons)

    International Nuclear Information System (INIS)

    Laurent Duclaux; Szymon Los; Michel Letellier; Philippe Azais; Roland Pellenq; Thomas Roussel; Xavier Fuhr

    2006-01-01

    Doping of microporous carbon by Li or K leads to an increase in the energy of adsorption of H 2 or D 2 molecules. Thus, the room temperature sorption capacities (at P≤3 MPa) can be higher than the ones of the raw materials after slight doping. However, the maximum H 2 (or D 2 ) storage uptake measured at T≤ 77 K is lower than the one of pristine materials as the sites of adsorption are occupied by alkali ions inserted in the micropores. The microporous adsorption sites of doped single-walled carbon nano-tubes, identified by neutron diffraction, are both the interstitial voids (in electric-arc or HiPCO tubes) in between the tubes and the central canals of the tubes (only in HiPCO tubes). (authors)

  14. A technology to improve formability for aluminum alloy thin-wall corrugated sheet component hydroforming

    Directory of Open Access Journals (Sweden)

    Lang Lihui

    2015-01-01

    Full Text Available The explosively forming projectile (EFP had been traditional adopted for the aluminum thin-walled corrugated sheet, whose deformation range is large but the formability is poor, and this process usually has problems of poor surface quality, long manufacturing cycle and high cost. The active hydroforming process was suggested to solve these issues during EFP. A new technology named as blank bulging by turning the upside down active hydroforming technology was proposed to overcome difficulties in non-uniform thickness distribution and cracking failure of corrugated sheet during the conventional hydroforming process. Both numerical simulations and experiments were conducted for this new technology. The result show that the deformation capacity of aluminum alloys can be improved effectively, and the more uniform distribution of wall thickness was obtained by this new method. It is conducted that the new method is universal for thin-walled, shallow drawing parts with complex section.

  15. Proposal of limit moment equation applicable to planar/non-planar flaw in wall thinned pipes under bending

    International Nuclear Information System (INIS)

    Tsuji, Masataka; Meshii, Toshiyuki

    2011-01-01

    Highlights: → A limit moment equation applicable to planar/non-planar flaw of 0 ≤ θ ≤ π found in wall thinned straight pipes was proposed. → An idea to rationally classify planar/non-planar flaw in wall thinned pipes was proposed. → The equation based on the experimental observation focused on the fracture mode. - Abstract: In this paper, a limit bending moment equation applicable to all types of planar and non-planar flaws in wall-thinned straight pipes under bending was proposed. A system to rationally classify the planar/non-planar flaws in wall-thinned pipes was suggested based on experimental observations focused on the fracture mode. The results demonstrate the importance of distinguishing between axial and circumferential long flaws in wall-thinned pipes.

  16. Enhancement of leak rate estimation model for corroded cracked thin tubes

    International Nuclear Information System (INIS)

    Chang, Y.S.; Jeong, J.U.; Kim, Y.J.; Hwang, S.S.; Kim, H.P.

    2010-01-01

    During the last couple of decades, lots of researches on structural integrity assessment and leak rate estimation have been carried out to prevent unanticipated catastrophic failures of pressure retaining nuclear components. However, from the standpoint of leakage integrity, there are still some arguments for predicting the leak rate of cracked components due primarily to uncertainties attached to various parameters in flow models. The purpose of present work is to suggest a leak rate estimation method for thin tubes with artificial cracks. In this context, 23 leak rate tests are carried out for laboratory generated stress corrosion cracked tube specimens subjected to internal pressure. Engineering equations to calculate crack opening displacements are developed from detailed three-dimensional elastic-plastic finite element analyses and then a simplified practical model is proposed based on the equations as well as test data. Verification of the proposed method is done through comparing leak rates and it will enable more reliable design and/or operation of thin tubes.

  17. New technical knowledge to be implemented to the revision of rules on pipe wall thinning management for PWR plants

    International Nuclear Information System (INIS)

    Hirai, Junya; Nakamura, Takao; Amano, Yoichi

    2013-01-01

    Rules for PWR plant pipe wall thinning management were formulated by the Japan Society of Mechanical Engineers in 2006. Since then thinning management of Japanese PWR plants has been carried out based on this rule. Pipe wall thinning phenomena to be dealt with in this rule have been identified in many piping components of power plants. New technical knowledge has been accumulated since the issuance of 2006 edition. We have formulated these knowledge and information about the thinning phenomena in PWR power plants. Given the history of application of this rule, we have to make our best effort to carry out a study of latest technical knowledge and implement them to the revision of rule and improve pipe wall thinning management. This paper summarizes the new technical knowledge and basis to be implemented to the revision of rules on pipe wall thinning management for PWR plants in Japan. (author)

  18. Development of an extremely thin-wall straw tracker operational in vacuum – The COMET straw tracker system

    International Nuclear Information System (INIS)

    Nishiguchi, H.; Evtoukhovitch, P.; Fujii, Y.; Hamada, E.; Mihara, S.; Moiseenko, A.; Noguchi, K.; Oishi, K.; Tanaka, S.; Tojo, J.; Tsamalaidze, Z.; Tsverava, N.; Ueno, K.; Volkov, A.

    2017-01-01

    The COMET experiment at J-PARC aims to search for a lepton-flavour violating process of muon to electron conversion in a muonic atom, μ-e conversion, with a branching-ratio sensitivity of better than 10 −16 , 4 orders of magnitude better than the present limit, in order to explore the parameter region predicted by most of well-motivated theoretical models beyond the Standard Model. The need for this sensitivity places several stringent requirements on the detector development. The experiment requires to detect the monochromatic electron of 105 MeV, the momentum resolution is primarily limited by the multiple scattering effect for this momentum region. Thus we need the very light material detector in order to achieve an excellent momentum resolution, better than 2%, for 100 MeV region. In order to fulfil such a requirement, the thin-wall straw-tube planar tracker has been developed by an extremely light material which is operational in vacuum. The COMET straw tracker consists of 9.8 mm diameter straw tube, longer than 1 m length, with 20-μm-thick Mylar foil and 70-nm-thick aluminium deposition. Currently even thinner and smaller, 12 μm thick and 5 mm diameter, straw is under development by the ultrasonic welding technique.

  19. Development of an extremely thin-wall straw tracker operational in vacuum – The COMET straw tracker system

    Energy Technology Data Exchange (ETDEWEB)

    Nishiguchi, H., E-mail: hajime.nishiguchi@kek.jp [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801 (Japan); Evtoukhovitch, P. [Joint Institute for Nuclear Research (JINR), Jolio-Curie Str.6, Dubna, Moscow 141980 (Russian Federation); Fujii, Y. [Institute of High Energy Physics (IHEP), 19B YuquanLu, Shijingshan district, Beijing 1000049 (China); Hamada, E.; Mihara, S. [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801 (Japan); Moiseenko, A. [Joint Institute for Nuclear Research (JINR), Jolio-Curie Str.6, Dubna, Moscow 141980 (Russian Federation); Noguchi, K.; Oishi, K.; Tanaka, S.; Tojo, J. [Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Tsamalaidze, Z.; Tsverava, N. [Joint Institute for Nuclear Research (JINR), Jolio-Curie Str.6, Dubna, Moscow 141980 (Russian Federation); Ueno, K. [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801 (Japan); Volkov, A. [Joint Institute for Nuclear Research (JINR), Jolio-Curie Str.6, Dubna, Moscow 141980 (Russian Federation)

    2017-02-11

    The COMET experiment at J-PARC aims to search for a lepton-flavour violating process of muon to electron conversion in a muonic atom, μ-e conversion, with a branching-ratio sensitivity of better than 10{sup −16}, 4 orders of magnitude better than the present limit, in order to explore the parameter region predicted by most of well-motivated theoretical models beyond the Standard Model. The need for this sensitivity places several stringent requirements on the detector development. The experiment requires to detect the monochromatic electron of 105 MeV, the momentum resolution is primarily limited by the multiple scattering effect for this momentum region. Thus we need the very light material detector in order to achieve an excellent momentum resolution, better than 2%, for 100 MeV region. In order to fulfil such a requirement, the thin-wall straw-tube planar tracker has been developed by an extremely light material which is operational in vacuum. The COMET straw tracker consists of 9.8 mm diameter straw tube, longer than 1 m length, with 20-μm-thick Mylar foil and 70-nm-thick aluminium deposition. Currently even thinner and smaller, 12 μm thick and 5 mm diameter, straw is under development by the ultrasonic welding technique.

  20. Domain wall conductivity in semiconducting hexagonal ferroelectric TbMnO3 thin films

    International Nuclear Information System (INIS)

    Kim, D J; Gruverman, A; Connell, J G; Seo, S S A

    2016-01-01

    Although enhanced conductivity of ferroelectric domain boundaries has been found in BiFeO 3 and Pb(Zr,Ti)O 3 films as well as hexagonal rare-earth manganite single crystals, the mechanism of the domain wall conductivity is still under debate. Using conductive atomic force microscopy, we observe enhanced conductance at the electrically-neutral domain walls in semiconducting hexagonal ferroelectric TbMnO 3 thin films where the structure and polarization direction are strongly constrained along the c-axis. This result indicates that domain wall conductivity in ferroelectric rare-earth manganites is not limited to charged domain walls. We show that the observed conductivity in the TbMnO 3 films is governed by a single conduction mechanism, namely, the back-to-back Schottky diodes tuned by the segregation of defects. (paper)

  1. Experimental validation of tape springs to be used as thin-walled space structures

    Science.gov (United States)

    Oberst, S.; Tuttle, S. L.; Griffin, D.; Lambert, A.; Boyce, R. R.

    2018-04-01

    With the advent of standardised launch geometries and off-the-shelf payloads, space programs utilising nano-satellite platforms are growing worldwide. Thin-walled, flexible and self-deployable structures are commonly used for antennae, instrument booms or solar panels owing to their lightweight, ideal packaging characteristics and near zero energy consumption. However their behaviour in space, in particular in Low Earth Orbits with continually changing environmental conditions, raises many questions. Accurate numerical models, which are often not available due to the difficulty of experimental testing under 1g-conditions, are needed to answer these questions. In this study, we present on-earth experimental validations, as a starting point to study the response of a tape spring as a representative of thin-walled flexible structures under static and vibrational loading. Material parameters of tape springs in a singly (straight, open cylinder) and a doubly curved design, are compared to each other by combining finite element calculations, with experimental laser vibrometry within a single and multi-stage model updating approach. While the determination of the Young's modulus is unproblematic, the damping is found to be inversely proportional to deployment length. With updated material properties the buckling instability margin is calculated using different slenderness ratios. Results indicate a high sensitivity of thin-walled structures to miniscule perturbations, which makes proper experimental testing a key requirement for stability prediction on thin-elastic space structures. The doubly curved tape spring provides closer agreement with experimental results than a straight tape spring design.

  2. Study of Weld Imperfections on Thin Aluminum Tubes According To ISO 10042

    CERN Document Server

    Rizkallah, Rabel

    2014-01-01

    The following report presents the work done as part of my summer student internship at CERN in the EN/MME group, and is divided into two parts. Part I of the report is a continuation of the work started previously by the student Quentin Drouhet, which aims at studying and classifying welding imperfections on various materials of small thicknesses. Drouhet worked on the welding imperfections found on thin Stainless Steel plates of thicknesses of 2 and 6 millimeters, welded using the GTAW (or TIG welding) process. My job was to conduct a similar study on thin Aluminum tubes welded using this same process. Part II of the report will introduce a new method for defect analysis that is still not available at CERN: the micro-tomographic testing

  3. Two simple methods for calculating the penetration time of a longitudinal magnetic field through the wall of a metallic tube

    International Nuclear Information System (INIS)

    Jimenez D, H.; Colunga S, S.; Lopez C, R.; Melendez L, L.; Ramos S, J.; Cabral P, A.; Gonzalez T, L.; Chavez A, E.; Valencia A, R.

    1991-06-01

    Two simple and fast methods to calculate the penetration time of a longitudinal magnetic field through the wall of a long metallic tube of circular cross section are presented. The first method is based upon the proposition of an 'effective penetration thickness' given by the polar angle average of all possible straight-line transverse penetration paths of field lines through the tube wall. This method provides a quick calculation that yields a remarkably good approximation to experimental and reported values of the penetration time. In the second method the tube is considered as a RL circuit. Thus the penetration time is given by the ratio L T /R T where L T is the inductance of the tube considered as a one turn coil, and R T is the tube resistance. This method is faster to apply than the previous one but the values obtained provide only a rough approximation to the penetration time. Applications of the two methods are given for the tokamak chambers of the Japanese 'HYBTOK', the Brazilian 'TBR' and the Mexican 'Novillo'. The resulting values of the penetration time approximate very well to the reported ones in the first two cases and to the experimental one in the last. The methods are also applied to calculate the penetration time in two long tubes, one of aluminum and other of copper. Calculated values approximate very well to measured values. (Author)

  4. Atomic layer deposition of copper thin film and feasibility of deposition on inner walls of waveguides

    Science.gov (United States)

    Yuqing, XIONG; Hengjiao, GAO; Ni, REN; Zhongwei, LIU

    2018-03-01

    Copper thin films were deposited by plasma-enhanced atomic layer deposition at low temperature, using copper(I)-N,N‧-di-sec-butylacetamidinate as a precursor and hydrogen as a reductive gas. The influence of temperature, plasma power, mode of plasma, and pulse time, on the deposition rate of copper thin film, the purity of the film and the step coverage were studied. The feasibility of copper film deposition on the inner wall of a carbon fibre reinforced plastic waveguide with high aspect ratio was also studied. The morphology and composition of the thin film were studied by atomic force microscopy and x-ray photoelectron spectroscopy, respectively. The square resistance of the thin film was also tested by a four-probe technique. On the basis of on-line diagnosis, a growth mechanism of copper thin film was put forward, and it was considered that surface functional group played an important role in the process of nucleation and in determining the properties of thin films. A high density of plasma and high free-radical content were helpful for the deposition of copper thin films.

  5. Evaluation of local allowable wall thickness of thinned pipe considering internal pressure and bending moment

    International Nuclear Information System (INIS)

    Kim, J. W.; Park, C. Y.; Kim, B. Y.

    2000-01-01

    This study proposed the local allowable wall thickness (LAWT) evaluation method for local wall thinned pipe subjected by internal pressure and bending moment. Also, LAWT was evaluated for simplified thinned pipe and the effect of axial extent of thinned area on LAWT was investigated. The results showed that LAWT predicted by present method was thinner, about 50%, than that evaluated by construction code and ASME Code Case N-597, while it was thicker, about 2 times, than that calculated by evaluation model based on pipe experiments. LAWT decreased with increasing axial extent of thinned area and was saturated above axial extent of pipe radius, which was a contrast to the results of ASME Code Case N-597 evaluation. The results of stress analysis with applied loading type indicated that the effect of axial extent of thinned area on LAWT was dependent on loading type considering in the evaluation. That is, the dependence of axial extent on LAWT is determined by magnitude of bending moment, and the contrary trend with axial extent in ASME Code Case is because ASME Code Case N-597 considers only internal pressure in the evaluation

  6. Analytical and numerical calculations of resistive wall impedances for thin beam pipe structures at low frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Niedermayer, U., E-mail: u.niedermayer@gsi.de [Technische Universitaet Darmstadt, Institut fuer Theorie Elektromagnetischer Felder, Schlossgartenstrasse 8, 64289 Darmstadt (Germany); Boine-Frankenheim, O. [Technische Universitaet Darmstadt, Institut fuer Theorie Elektromagnetischer Felder, Schlossgartenstrasse 8, 64289 Darmstadt (Germany)

    2012-09-21

    The resistive wall impedance is one of the main sources for beam instabilities in synchrotrons and storage rings. The fast ramped SIS18 synchrotron at GSI and the projected SIS100 synchrotron for FAIR both employ thin (0.3 mm) stainless steel beam pipes in order to reduce eddy current effects. The lowest betatron sidebands are at about 100 kHz, which demands accurate impedance predictions in the low frequency (LF) range where the beam pipe and possibly also the structures behind the pipe are the dominating impedance sources. The longitudinal and transverse resistive wall impedances of a circular multi-layer pipe are calculated analytically using the field matching technique. We compare the impedances obtained from a radial wave model, which corresponds to the setup used in bench measurements, with the axial wave model, which corresponds to an actual beam moving with relativistic velocity. For thin beam pipes the induced wall current and the corresponding shielding properties of the pipe are important. In both models the wall current is obtained analytically. The characteristic frequencies for the onset of the wall current are calculated from equivalent lumped element circuits corresponding to the radial model. For more complex structures, like the SIS100 beam pipe, we use a numerical method, in which the impedance is obtained from the total power loss. The method is validated by the analytic expressions for circular beam pipes.

  7. Numerical modelling of solidification of thin walled hypereutectic ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Hattel, Jesper; Tiedje, Niels

    2006-01-01

    Numerical simulation of solidification of ductile cast iron is normally based on a model where graphite nodules are surrounded by an austenite shell. The two phases are then growing as two concentric spheres governed by diffusion of carbon through the austenite shell. Experiments have however shown...... simulation of thin-walled ductile iron castings. Simulations have been performed with a 1-D numerical solidi¬fication model that includes the precipitation of non-eutectic austenite during the eutectic stage. Results from the simulations have been compared with experimental castings with wall thick...

  8. Cellular automaton modelling of ductile iron microstructure in the thin wall casting

    International Nuclear Information System (INIS)

    Burbelko, A A; Gurgul, D; Kapturkiewicz, W; Górny, M

    2012-01-01

    The mathematical model of the globular eutectic solidification in 2D was designed. Proposed model is based on the Cellular Automaton Finite Differences (CA-FD) calculation method. Model has been used for studies of the primary austenite and of globular eutectic grains growth during the ductile iron solidification in the thin wall casting. Model takes into account, among other things, non-uniform temperature distribution in the casting wall cross-section, kinetics of the austenite and graphite grains nucleation, and non-equilibrium nature of the interphase boundary migration.

  9. Analysis of moderately thin-walled beam cross-sections by cubic isoparametric elements

    DEFF Research Database (Denmark)

    Høgsberg, Jan Becker; Krenk, Steen

    2014-01-01

    In technical beam theory the six equilibrium states associated with homogeneous tension, bending, shear and torsion are treated as individual load cases. This enables the formulation of weak form equations governing the warping from shear and torsion. These weak form equations are solved...... numerically by introducing a cubic-linear two-dimensional isoparametric element. The cubic interpolation of this element accurately represents quadratic shear stress variations along cross-section walls, and thus moderately thin-walled cross-sections are effectively discretized by these elements. The ability...

  10. Radiant and convective heat transfer for flow of a transparent gas in a short tube with prescribed sinusoidal wall heat flux

    International Nuclear Information System (INIS)

    de Lemos, M.J.S.

    1982-01-01

    The present analysis accounts for radiant and convective heat transfer for a transparent fluid flowing in a short tube with prescribed wall heat flux. The heat flux distribution used was of sine shape with maximum at the middle of the tube. Such a solution is the approximate one for axial power in a nuclear reactor. The solutions for the tube wall and gas bulk temperatures were obtained by successive substitutions for the wall and gas balance energy equations. The results show a decrease of 30% for the maximum wall temperature using black surface (e = 1). In this same case, the increasing in the gas temperature shows a decrease of 58%

  11. Review of industry efforts to manage pressurized water reactor feedwater nozzle, piping, and feedring cracking and wall thinning

    Energy Technology Data Exchange (ETDEWEB)

    Shah, V.N.; Ware, A.G.; Porter, A.M.

    1997-03-01

    This report presents a review of nuclear industry efforts to manage thermal fatigue, flow-accelerated corrosion, and water hammer damage to pressurized water reactor (PWR) feedwater nozzles, piping, and feedrings. The review includes an evaluation of design modifications, operating procedure changes, augmented inspection and monitoring programs, and mitigation, repair and replacement activities. Four actions were taken: (a) review of field experience to identify trends of operating events, (b) review of technical literature, (c) visits to PWR plants and a PWR vendor, and (d) solicitation of information from 8 other countries. Assessment of field experience is that licensees have apparently taken sufficient action to minimize feedwater nozzle cracking caused by thermal fatigue and wall thinning of J-tubes and feedwater piping. Specific industry actions to minimize the wall-thinning in feedrings and thermal sleeves were not found, but visual inspection and necessary repairs are being performed. Assessment of field experience indicates that licensees have taken sufficient action to minimize steam generator water hammer in both top-feed and preheat steam generators. Industry efforts to minimize multiple check valve failures that have allowed backflow of steam from a steam generator and have played a major role in several steam generator water hammer events were not evaluated. A major finding of this review is that analysis, inspection, monitoring, mitigation, and replacement techniques have been developed for managing thermal fatigue and flow-accelerated corrosion damage to feedwater nozzles, piping, and feedrings. Adequate training and appropriate applications of these techniques would ensure effective management of this damage.

  12. Review of industry efforts to manage pressurized water reactor feedwater nozzle, piping, and feedring cracking and wall thinning

    International Nuclear Information System (INIS)

    Shah, V.N.; Ware, A.G.; Porter, A.M.

    1997-03-01

    This report presents a review of nuclear industry efforts to manage thermal fatigue, flow-accelerated corrosion, and water hammer damage to pressurized water reactor (PWR) feedwater nozzles, piping, and feedrings. The review includes an evaluation of design modifications, operating procedure changes, augmented inspection and monitoring programs, and mitigation, repair and replacement activities. Four actions were taken: (a) review of field experience to identify trends of operating events, (b) review of technical literature, (c) visits to PWR plants and a PWR vendor, and (d) solicitation of information from 8 other countries. Assessment of field experience is that licensees have apparently taken sufficient action to minimize feedwater nozzle cracking caused by thermal fatigue and wall thinning of J-tubes and feedwater piping. Specific industry actions to minimize the wall-thinning in feedrings and thermal sleeves were not found, but visual inspection and necessary repairs are being performed. Assessment of field experience indicates that licensees have taken sufficient action to minimize steam generator water hammer in both top-feed and preheat steam generators. Industry efforts to minimize multiple check valve failures that have allowed backflow of steam from a steam generator and have played a major role in several steam generator water hammer events were not evaluated. A major finding of this review is that analysis, inspection, monitoring, mitigation, and replacement techniques have been developed for managing thermal fatigue and flow-accelerated corrosion damage to feedwater nozzles, piping, and feedrings. Adequate training and appropriate applications of these techniques would ensure effective management of this damage

  13. Iron melt flow in thin-walled sections using vertically parted moulds

    DEFF Research Database (Denmark)

    Larsen, Per; Tiedje, Niels

    2004-01-01

    gating systems are used small changes in the casting conditions can change the flow patterns radically. Flow in thin walled sections is not only important in thin walled part. This is illustrated with a brake disc as example. 3 different layouts have been made. The filling sequences have been recorded...... sizes of the dynamic and braking forces in the gating system.......Reducing the fuel consumption of vehicles can be done in many ways. A general way of doing it, is to reduce the weight as it is applicable together with all other means of saving fuel. Even though iron castings have been used in cars from the first car ever build, a big potential still exist...

  14. Evaluation of stresses in large diameter, thin walled piping at support locations

    International Nuclear Information System (INIS)

    Bryan, B.J.; Flanders, H.E. Jr.; Rawls, G.B. Jr.

    1992-01-01

    The highest stresses in many thin walled piping systems are the local stresses at the pipe supports. These secondary stresses are caused by saddles or other structural discontinuities that restrain pipe ovalization. A static analysis of a thin walled pipe supported on structural steel saddle under dead weight loading is presented. The finite element analysis is performed using a shell model with distributed gravity and hydrostatic pressure loading. Parametric studies on global and local stress are performed to determine the effect of the pipe diameter to thickness ratio. Two aspects of the saddle design are also investigated: the effect of saddle width, and the effect of saddle wrap angle. Additionally, the computed stresses are compared to closed form solutions

  15. The thin-walled abnormity measurement technology research based on CCD

    International Nuclear Information System (INIS)

    Wang Bin

    2014-01-01

    The character of the thin-walled irregular parts is: the measured parameters for spatial structure size, need to design special measurement positioning fixture to complete detection, the wall thickness is very thin, and the processing is composite, its size is small and shape is complex, it is difficulty to collect image edge by using the optical measurement method. In this paper, a special measurement method of CCD that based on the image measurement technique was advanced, this kind of parts was measured quickly, accurately and automaticly through design the high precision positioning fixture and image acquisition method. At the same time, the comprehensive evaluation standard was given to assess the measurement accuracy method, and the reliability of measurement method was ensured. (author)

  16. Advanced management of pipe wall thinning based on prediction-monitor fusion

    International Nuclear Information System (INIS)

    Kojima, Fumio; Uchida, Shunsuke

    2012-01-01

    This article is concerned with pipe wall thinning management system by means of hybrid use of simulation and monitoring. First, the computer-aided simulation for predicting wear rate of piping system is developed based on elucidation of thinning mechanism such as flow-accelerated corrosion (FAC). The accurate prediction of wear rate allows us the useful information on region of interest of inspection. Secondly, several monitoring methods are considered in accordance with interest of inspection. Thirdly, probability of detection (POD) is considered for the reliability of inspection data. The final part of this article is devoted to how to improve safety performance under the hybrid use of predicting and monitoring on the proposed pipe wall management. (author)

  17. Trend of field data on pipe wall thinning for BWR power plants

    International Nuclear Information System (INIS)

    Hakii, Junichi; Hiranuma, Naoki; Hidaka, Akitaka

    2009-01-01

    Strongly motivated by every stakeholder not to repeat Mihama Nuclear Power Station pipe rupture accident in August 2004, JSME Main Committee on Codes and Standards on Power Generation Facilities immediately launched a special task force to develop Rules on Pipe Wall Thinning Management for BWR, PWR and fossil Power Plants respectively. The authors describes the process of the development of Rules for BWR Power Plans from the view point of collections and analysis of fields data of pipe wall thinning. Through its activities, the authors confirmed the existing findings, like the effect of Oxygen injection, turbulence and dependence on coolant temperature, derived from series of laboratory-scaled experiments in FAC and coolant velocities effects in LDI. Further based upon the said proven findings with field data, they explain the adequacy of major concept of the rule such as separate treatment of FAC (Flow Accelerated Corrosion) and LDI (Liquid Droplet Impingement). (author)

  18. Assessment of the Manufacturing Possibility of Thin-Walled Robotic Portals for Conveyor Worklace

    Directory of Open Access Journals (Sweden)

    Peter Michalik

    2018-03-01

    Full Text Available The paper discusses evaluation of machining solutions for oversized thin-walled robotic portal component for conveyance workplaces. The following portal CNC machining centers have been selected. Firstly, a FSGC 300 “portal type” portal was proposed, with a 50000 mm “X” axis and Heidenhain control system, the second portal was a DMU 340 portal with the maximum axis “X” of 6000 mm and Siemens Sinumerik control system and the last portal was the VF-10 / 40 one, with the maximum axis “X” of 3048 mm and Fanuc control system. Further, the method of fixing a thin-walled robotic portal is designed and individual options are evaluated for their economy. The CAM software application used for programming the production was SolidWorks.

  19. Analysis on Forced Vibration of Thin-Wall Cylindrical Shell with Nonlinear Boundary Condition

    Directory of Open Access Journals (Sweden)

    Qiansheng Tang

    2016-01-01

    Full Text Available Forced vibration of thin-wall cylindrical shell under nonlinear boundary condition was discussed in this paper. The nonlinear boundary was modeled as supported clearance in one end of shell and the restraint was assumed as linearly elastic in the radial direction. Based on Sanders’ shell theory, Lagrange equation was utilized to derive the nonlinear governing equations of cylindrical shell. The displacements in three directions were represented by beam functions and trigonometric functions. In the study of nonlinear dynamic responses of thin-wall cylindrical shell with supported clearance under external loads, the Newmark method is used to obtain time history, frequency spectrum plot, phase portraits, Poincare section, bifurcation diagrams, and three-dimensional spectrum plot with different parameters. The effects of external loads, supported clearance, and support stiffness on nonlinear dynamics behaviors of cylindrical shell with nonlinear boundary condition were discussed.

  20. Development of a Thin-Wall Magnesium side door Inner Panel for Automobiles

    Energy Technology Data Exchange (ETDEWEB)

    Jekl, J.; Auld, J.; Sweet, C.; Carter, Jon; Resch, Steve; Klarner, A.; Brevick, J.; Luo, A.

    2015-05-17

    Cast magnesium side door inner panels can provide a good combination of weight, functional, manufacturing and economical requirements. However, several challenges exist including casting technology for thin-wall part design, multi-material incompatibility and relatively low strength vs steel. A project has been initiated, supported by the US Department of Energy, to design and develop a lightweight frame-under-glass door having a thin-wall, full die-cast, magnesium inner panel. This development project is the first of its kind within North America. Phase I of the project is now complete and the 2.0mm magnesium design, through casting process enablers, has met or exceeded all stiffness requirements, with significant mass reduction and part consolidation. In addition, a corrosion mitigation strategy has been established using industry-accepted galvanic isolation methods and coating technologies.

  1. Acoustic emission monitoring during hydrotest of a thin wall pressure vessel

    International Nuclear Information System (INIS)

    Fontana, E.; Grugni, G.; Panzani, C.; Pirovano, B.; Possa, G.; Tonolini, F.

    1976-01-01

    Results are presented of the acoustic emission monitoring during hydrotests of a thin wall steel pressure vessel. Location of acoustic sources was based on longitudinal wave front detection. The careful calibration of the three sensors used for acoustic source location was found to be very useful, and allowed an accurate location error analysis. Acoustic emission in the hydrotests was found to be due mainly to stress release in weld seams

  2. On designing of the thin-walled bars in the light of theory and experiments

    International Nuclear Information System (INIS)

    Obrebski, J.B.; Urbaniak, Z.; El-Awady, M.E.

    1992-01-01

    The paper presents some data and conclusions derived from the experiments and computations concerning the influence of constructional details and solutions on strength of straight thin-walled bars. The attention specially is paid to: the different instability phenomena i.e. local and global for the bar with any cross-section, the capacity of the bar by bending-torsional loading, the theory of 2d approximation, and comparisons of theoretical problems mentioned above with the proper experiments. (orig.)

  3. Analytical Investigation of Elastic Thin-Walled Cylinder and Truncated Cone Shell Intersection Under Internal Pressure

    OpenAIRE

    Zamani, J.; Soltani, B.; Aghaei, M.

    2014-01-01

    An elastic solution of cylinder-truncated cone shell intersection under internal pressure is presented. The edge solution theory that has been used in this study takes bending moments and shearing forces into account in the thin-walled shell of revolution element. The general solution of the cone equations is based on power series method. The effect of cone apex angle on the stress distribution in conical and cylindrical parts of structure is investigated. In addition, the effect of the inter...

  4. Experimental Investigation of Chatter Dynamics in Thin-walled Tubular Parts Turning

    OpenAIRE

    GERASIMENKO, Artem; GUSKOV, Mikhail; LORONG, Philippe; DUCHEMIN, Jérôme; GOUSKOV, Alexander

    2016-01-01

    Chatter prediction is nowadays frequently carried out for machining operations involving deformable parts or tools. These analyses are commonly based on the uncoupled elements of the system: frequency response of the deformable parts under non-rotating conditions and cutting law. The present investigation puts forward the dynamics of a thin-walled tubular part during straight axial turning undergoing chatter instability. Studied system’s peculiarities include quasi-static nominal cutting cond...

  5. Collapse moment estimation by support vector machines for wall-thinned pipe bends and elbows

    International Nuclear Information System (INIS)

    Na, Man Gyun; Kim, Jin Weon; Hwang, In Joon

    2007-01-01

    The collapse moment due to wall-thinned defects is estimated through support vector machines with parameters optimized by a genetic algorithm. The support vector regression models are developed and applied to numerical data obtained from the finite element analysis for wall-thinned defects in piping systems. The support vector regression models are optimized by using both the data sets (training data and optimization data) prepared for training and optimization, and its performance verification is performed by using another data set (test data) different from the training data and the optimization data. In this work, three support vector regression models are developed, respectively, for three data sets divided into the three classes of extrados, intrados, and crown defects, which is because they have different characteristics. The relative root mean square (RMS) errors of the estimated collapse moment are 0.2333% for the training data, 0.5229% for the optimization data and 0.5011% for the test data. It is known from this result that the support vector regression models are sufficiently accurate to be used in the integrity evaluation of wall-thinned pipe bends and elbows

  6. Application of irradiation process for the production of thin wall wires

    International Nuclear Information System (INIS)

    Saito, E.

    1977-01-01

    The demand for thin wall crosslinked PVC or polyethylene insulated wires in Japan was about 15,000,000 dollars in value in 1975. Their annual sales in 1980 are estimated at about 40 million dollars which will account for approximately 20% of the sales of all thin wall thermoplastic insulated wires expected for the same year. A comparative study was made of the irradiation process and the chemical process for manufacture of wires with crosslinked PVC or polyethylene insulation. Having found the excellence of the irradiation process an accelerator (500 KeV, 65mA) was installed in 1973 and production was begun of several types of thin wall irradiation crosslinked PVC and polyethylene insulated wires ranging from 0.06 mm 2 to 2.0 mm 2 in the cross-sectional area of conductor, successfully putting them in extensive commercial application. This report compares the irradiation process and the chemical process, properties of several types of irradiation crosslinked PVC, and polyethylene insulated wires and their applications. (author)

  7. Numerical study on injection parameters optimization of thin wall and biodegradable polymers parts

    Science.gov (United States)

    Santos, C.; Mendes, A.; Carreira, P.; Mateus, A.; Malça, C.

    2017-07-01

    Nowadays, the molds industry searches new markets, with diversified and added value products. The concept associated to the production of thin walled and biodegradable parts mostly manufactured by injection process has assumed a relevant importance due to environmental and economic factors. The growth of a global consciousness about the harmful effects of the conventional polymers in our life quality associated with the legislation imposed, become key factors for the choice of a particular product by the consumer. The target of this work is to provide an integrated solution for the injection of parts with thin walls and manufactured using biodegradable materials. This integrated solution includes the design and manufacture processes of the mold as well as to find the optimum values for the injection parameters in order to become the process effective and competitive. For this, the Moldflow software was used. It was demonstrated that this computational tool provides an effective responsiveness and it can constitute an important tool in supporting the injection molding of thin-walled and biodegradable parts.

  8. ON-POWER DETECTION OF PIPE WALL-THINNED DEFECTS USING IR THERMOGRAPHY IN NPPS

    Directory of Open Access Journals (Sweden)

    JU HYUN KIM

    2014-04-01

    Full Text Available Wall-thinned defects caused by accelerated corrosion due to fluid flow in the inner pipe appear in many structures of the secondary systems in nuclear power plants (NPPs and are a major factor in degrading the integrity of pipes. Wall-thinned defects need to be managed not only when the NPP is under maintenance but also when the NPP is in normal operation. To this end, a test technique was developed in this study to detect such wall-thinned defects based on the temperature difference on the surface of a hot pipe using infrared (IR thermography and a cooling device. Finite element analysis (FEA was conducted to examine the tendency and experimental conditions for the cooling experiment. Based on the FEA results, the equipment was configured before the cooling experiment was conducted. The IR camera was then used to detect defects in the inner pipe of the pipe specimen that had artificially induced defects. The IR thermography developed in this study is expected to help resolve the issues related to the limitations of non-destructive inspection techniques that are currently conducted for NPP secondary systems and is expected to be very useful on the NPPs site.

  9. Development of Integrated Die Casting Process for Large Thin-Wall Magnesium Applications

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Jon T. [General Motors LLC, Warren, MI (United States); Wang, Gerry [Meridian Lightweight Technologies, Plymouth MI (United States); Luo, Alan [General Motors LLC, Warren, MI (United States)

    2017-11-29

    The purpose of this project was to develop a process and product which would utilize magnesium die casting and result in energy savings when compared to the baseline steel product. The specific product chosen was a side door inner panel for a mid-size car. The scope of the project included: re-design of major structural parts of the door, design and build of the tooling required to make the parts, making of parts, assembly of doors, and testing (both physical and simulation) of doors. Additional work was done on alloy development, vacuum die casting, and overcasting, all in order to improve the performance of the doors and reduce cost. The project achieved the following objectives: 1. Demonstrated ability to design a large thin-wall magnesium die casting. 2. Demonstrated ability to manufacture a large thin-wall magnesium die casting in AM60 alloy. 3. Tested via simulations and/or physical tests the mechanical behavior and corrosion behavior of magnesium die castings and/or lightweight experimental automotive side doors which incorporate a large, thin-wall, powder coated, magnesium die casting. Under some load cases, the results revealed cracking of the casting, which can be addressed with re-design and better material models for CAE analysis. No corrosion of the magnesium panel was observed. 4. Using life cycle analysis models, compared the energy consumption and global warming potential of the lightweight door with those of a conventional steel door, both during manufacture and in service. Compared to a steel door, the lightweight door requires more energy to manufacture but less energy during operation (i.e., fuel consumption when driving vehicle). Similarly, compared to a steel door, the lightweight door has higher global warming potential (GWP) during manufacture, but lower GWP during operation. 5. Compared the conventional magnesium die casting process with the “super-vacuum” die casting process. Results achieved with cast tensile bars suggest some

  10. The apical actin fringe contributes to localized cell wall deposition and polarized growth in the lily pollen tube.

    Science.gov (United States)

    Rounds, Caleb M; Hepler, Peter K; Winship, Lawrence J

    2014-09-01

    In lily (Lilium formosanum) pollen tubes, pectin, a major component of the cell wall, is delivered through regulated exocytosis. The targeted transport and secretion of the pectin-containing vesicles may be controlled by the cortical actin fringe at the pollen tube apex. Here, we address the role of the actin fringe using three different inhibitors of growth: brefeldin A, latrunculin B, and potassium cyanide. Brefeldin A blocks membrane trafficking and inhibits exocytosis in pollen tubes; it also leads to the degradation of the actin fringe and the formation of an aggregate of filamentous actin at the base of the clear zone. Latrunculin B, which depolymerizes filamentous actin, markedly slows growth but allows focused pectin deposition to continue. Of note, the locus of deposition shifts frequently and correlates with changes in the direction of growth. Finally, potassium cyanide, an electron transport chain inhibitor, briefly stops growth while causing the actin fringe to completely disappear. Pectin deposition continues but lacks focus, instead being delivered in a wide arc across the pollen tube tip. These data support a model in which the actin fringe contributes to the focused secretion of pectin to the apical cell wall and, thus, to the polarized growth of the pollen tube. © 2014 American Society of Plant Biologists. All Rights Reserved.

  11. Copper hexacyanoferrate functionalized single-walled carbon nano-tubes for selective cesium extraction

    International Nuclear Information System (INIS)

    Draouil, H.; Alvarez, L.; Bantignies, J.L.; Causse, J.; Cambedouzou, J.; Flaud, V.; Zaibi, M.A.; Oueslati, M.

    2017-01-01

    Single-walled carbon nano-tubes (SWCNTs) are functionalized with copper hexacyanoferrate (CuHCF) nanoparticles to prepare solid substrates for sorption of cesium ions (Cs + ) from liquid outflows. The high mechanical resistance and large electrical conductivity of SWCNTs are associated with the ability of CuHCF nanoparticles to selectively complex Cs + ions in order to achieve membrane-like buckypapers presenting high loading capacity of cesium. The materials are thoroughly characterized using electron microscopy, Raman scattering, X-ray photoelectron spectroscopy and thermogravimetric analyses. Cs sorption isotherms are plotted after having measured the Cs + concentration by liquid phase ionic chromatography in the solution before and after exposure to the materials. It is found that the total sorption capacity of the material reaches 230 mg.g -1 , and that about one third of the sorbed Cs (80 mg.g -1 ) is selectively complexed in the CuHCF nanoparticles grafted on SWCNTs. The quantification of Cs + ions on different sorption sites is made for the first time, and the high sorption rates open interesting outlooks in the integration of such materials in devices for the controlled sorption and desorption of these ions. (authors)

  12. Radiation transmission type pipe wall thinning detection device and measuring instruments utilizing ionizing radiation

    International Nuclear Information System (INIS)

    Higashi, Yasuhiko

    2009-01-01

    We developed the device to detect thinning of pipe thorough heat insulation in Power Plant, etc, even while the plant is under operation. It is necessary to test many parts of many pipes for pipe wall thinning management, but it is difficult within a limited time of the routine test. This device consists of detector and radiation source, which can detect the pipe (less than 500 mm in external diameter, less than 50 mm in thickness) with 1.6%-reproducibility (in a few-minutes measurement), based on the attenuation rate. Operation is easy and effective without removing the heat insulation. We will expand this thinning detection system, and contribute the safety of the Plant. (author)

  13. PRODUCTION OF HIGHER STRENGTH THIN WALLED GLOW DISCHARGE POLYMER SHELLS FOR CRYOGENIC EXPERIMENTS AT OMEGA

    International Nuclear Information System (INIS)

    NIKROO, A; CZECHOWICZ, DG; CASTILLO, ER; PONTELANDOLFO, JM

    2002-01-01

    OAK A271 PRODUCTION OF HIGHER STRENGTH THIN WALLED GLOW DISCHARGE POLYMER SHELLS FOR CRYOGENIC EXPERIMENTS AT OMEGA. Thin walled polymer shells are needed for OMEGA cryogenic laser experiments. These capsules need to be about 900 (micro)m in diameter and as thin as possible (approx 1-2 (micro)m), while having enough strength to be filled with DT as fast as possible to about 1000 atm. The authors have found that by optimizing the coating parameters in the glow discharge polymer (GDP) deposition system, traditionally used for making ICF targets, they can routinely make robust, ∼ 1.5 (micro)m thick, 900 (micro)m diameter GDP shells with buckle strengths of over 0.3 atm. This is twice the strength of shells made prior to the optimization and is comparable to values quoted for polyimide shells. In addition, these shells were found to be approximately three times more permeable and over 20% denser than previously made GDP shells. The combination of higher strength and permeability is ideal for direct drive cryogenic targets at OMEGA. Shells as thin as 0.5 (micro)m have been made. In this paper, the authors discuss the shell fabrication process, effects of modifying various GDP deposition parameters on shell properties and chemical composition

  14. Modelling of Eutectic Saturation Influence on Microstructure in Thin Wall Ductile Iron Casting Using Cellular Automata

    Directory of Open Access Journals (Sweden)

    Burbelko A.A.

    2012-12-01

    Full Text Available The mathematical model of the globular eutectic solidification in 2D was designed. Proposed model is based on the Cellular Automaton Finite Differences (CA-FD calculation method. Model has been used for studies of the primary austenite and of globular eutectic grains growth during the ductile iron solidification in the thin wall casting. Model takes into account, among other things, non-uniform temperature distribution in the casting wall cross-section, kinetics of the austenite and graphite grains nucleation, and non-equilibrium nature of the interphase boundary migration. Calculation of eutectic saturation influence (Sc = 0.9 - 1.1 on microstructure (austenite and graphite fraction, density of austenite and graphite grains and temperature curves in 2 mm wall ductile iron casting has been done.

  15. Analysis of Pipe Wall-thinning Caused by Water Chemistry Change in Secondary System of Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Hun; Hwang, Kyeongmo [KEPCO E and C, Gimcheon (Korea, Republic of); Moon, Seung-Jae [Hanyang University, Seoul (Korea, Republic of)

    2015-12-15

    Pipe wall-thinning by flow-accelerated corrosion (FAC) is a significant and costly damage of secondary system piping in nuclear power plants (NPPs). All NPPs have their management programs to ensure pipe integrity from wall-thinning. This study analyzed the pipe wall-thinning caused by changing the amine, which is used for adjusting the water chemistry in the secondary system of NPPs. The pH change was analyzed according to the addition of amine. Then, the wear rate calculated in two different amines was compared at the steam cycle in NPPs. As a result, increasing the pH at operating temperature (Hot pH) can reduce the rate of FAC damage significantly. Wall-thinning is affected by amine characteristics depending on temperature and quality of water.

  16. Effect of two dimensional heat conduction within the wall on heat transfer of a tube partially heated on its circumference

    International Nuclear Information System (INIS)

    Satoh, Isao; Kurosaki, Yasuo

    1987-01-01

    This paper dealt with the numerical calculations of the heat transfer of a tube partially heated on its circumference, considering two-dimensional heat conduction within the wall. The contribution of the unheated region of the tube wall to heat tranfer of the heated region was explained by the term of 'fin efficiency of psuedo-fin', it was clarified that the fin efficiency of the unheated region was little affected by the temperature difference between the inner and outer surfaces of the wall, and could be approximated by the fin efficency of a rectangular fin. Both the circumferential and radial heat conductions within the wall affected the temperature difference between the inner and outer surfaces of the heated region; however, the effect of the temperature difference on the circumferentially average Nusselt number could be obtained by using the analytical solution of radially one-dimensional heat conduction. Using these results, a diagram showing the effect of wall conduction on heat transfer, which is useful for designing the circumferentially nonuniformly heated coolant passages, was obtained. (author)

  17. Generation of plastic influence functions for J-integral and crack opening displacement of thin-walled pipes with a short circumferential through-wall crack

    International Nuclear Information System (INIS)

    Park, Jeong Soon; Choi, Young Hwan; Im, Seyoung

    2014-01-01

    Fracture mechanics parameters such as the J-integral and crack opening displacement (COD), are necessary for Leak-Before-Break (LBB) evaluation. The famous two estimation methods, the GE/EPRI and the Reference Stress Method (RSM), have their applicability limit with regard to the ratio of a pipe mean radius to thickness (R m /t). In order to extend their applicability limit to a thin walled pipe, several finite element analyses are performed for the J-integral and COD, and then new plastic influence functions are developed for thin-walled pipes with a short circumferential through-wall crack. With the newly generated plastic influence functions, the GE/EPRI and the RSM give closer results with those obtained from detailed finite element analyses. In addition, C*-integral and COD rate are estimated by using the new plastic influence functions and they are well matched with elastic–creep finite element analysis results under the power-law creep condition. Since the LBB concept can be applied to a piping system in a Korean Sodium-cooled Fast Reactor (SFR) which is designed to have thin-walled pipes and to operate in high temperature enough to cause creep, this paper can be applied for the LBB assessment of thin-walled pipes with a short through-wall crack in the SFR

  18. Flow and axial dispersion in a sinusoidal-walled tube: Effects of inertial and unsteady flows

    Science.gov (United States)

    Richmond, Marshall C.; Perkins, William A.; Scheibe, Timothy D.; Lambert, Adam; Wood, Brian D.

    2013-12-01

    In this work, we consider a sinusoidal-walled tube (a three-dimensional tube with sinusoidally-varying diameter) as a simplified conceptualization of flow in porous media. Direct numerical simulation using computational fluid dynamics (CFD) methods was used to compute velocity fields by solving the Navier-Stokes equations, and also to numerically solve the volume averaging closure problem, for a range of Reynolds numbers (Re) spanning the low-Re to inertial flow regimes, including one simulation at Re=449 for which unsteady flow was observed. The longitudinal dispersion observed for the flow was computed using a random walk particle tracking method, and this was compared to the longitudinal dispersion predicted from a volume-averaged macroscopic mass balance using the method of volume averaging; the results of the two methods were consistent. Our results are compared to experimental measurements of dispersion in porous media and to previous theoretical results for both the low-Re, Stokes flow regime and for values of Re representing the steady inertial regime. In the steady inertial regime, a power-law increase in the effective longitudinal dispersion (DL) with Re was found, and this is consistent with previous results. This rapid rate of increase is caused by trapping of solute in expansions due to flow separation (eddies). One unsteady (but non-turbulent) flow case (Re=449) was also examined. For this case, the rate of increase of DL with Re was smaller than that observed at lower Re. Velocity fluctuations in this regime lead to increased rates of solute mass transfer between the core flow and separated flow regions, thus diminishing the amount of tailing caused by solute trapping in eddies and thereby reducing longitudinal dispersion. The observed tailing was further explored through analysis of concentration skewness (third moment) and its assymptotic convergence to conventional advection-dispersion behavior (skewness = 0). The method of volume averaging was

  19. Effects of microporosity on the elasticity and yielding of thin-walled metallic hollow spheres

    International Nuclear Information System (INIS)

    Song, Jinliang; Sun, Quansheng; Yang, Zhenning; Luo, Shengmin; Xiao, Xianghui; Arwade, Sanjay R.; Zhang, Guoping

    2017-01-01

    Knowledge of the mechanical properties of porous metallic hollow spheres (MHS) thin wall is of key importance for understanding the engineering performance of both individual ultralight MHS and the innovative MHS-based bulk foams. This paper presents the first integrated experimental and numerical study to determine the elasticity and yielding of the porous MHS wall and their dependence on its microporosity. Nanoindentation was used to probe the Young's modulus and hardness of the nonporous MHS wall material, and synchrotron X-ray computed tomography (XCT) conducted to obtain its porous microstructure and pore morphology. Three-dimensional finite element modeling was performed to obtain the mechanical response of microcubes with varying porosity trimmed from the XCT-derived real digital model of the porous MHS wall. Results show that both the Young's modulus and yield strength of the porous wall decrease nonlinearly with increasing porosity, and their relationships follow the same format of a power law function and agree well with prior experimental results. The empirical relations also reflect certain features of pore morphology, such as pore connectivity and shape. These findings can shed lights on the design, manufacturing, and modeling of individual MHS and MHS-based foams.

  20. Effects of microporosity on the elasticity and yielding of thin-walled metallic hollow spheres

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jinliang [Department of Civil Engineering, Northeast Forestry University, Harbin 150040 (China); Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003 (United States); Sun, Quansheng [Department of Civil Engineering, Northeast Forestry University, Harbin 150040 (China); Yang, Zhenning; Luo, Shengmin [Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003 (United States); Xiao, Xianghui [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Arwade, Sanjay R. [Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003 (United States); Zhang, Guoping, E-mail: zhangg@umass.edu [Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003 (United States)

    2017-03-14

    Knowledge of the mechanical properties of porous metallic hollow spheres (MHS) thin wall is of key importance for understanding the engineering performance of both individual ultralight MHS and the innovative MHS-based bulk foams. This paper presents the first integrated experimental and numerical study to determine the elasticity and yielding of the porous MHS wall and their dependence on its microporosity. Nanoindentation was used to probe the Young's modulus and hardness of the nonporous MHS wall material, and synchrotron X-ray computed tomography (XCT) conducted to obtain its porous microstructure and pore morphology. Three-dimensional finite element modeling was performed to obtain the mechanical response of microcubes with varying porosity trimmed from the XCT-derived real digital model of the porous MHS wall. Results show that both the Young's modulus and yield strength of the porous wall decrease nonlinearly with increasing porosity, and their relationships follow the same format of a power law function and agree well with prior experimental results. The empirical relations also reflect certain features of pore morphology, such as pore connectivity and shape. These findings can shed lights on the design, manufacturing, and modeling of individual MHS and MHS-based foams.

  1. Size Control of Porous Silicon-Based Nanoparticles via Pore-Wall Thinning.

    Science.gov (United States)

    Secret, Emilie; Leonard, Camille; Kelly, Stefan J; Uhl, Amanda; Cozzan, Clayton; Andrew, Jennifer S

    2016-02-02

    Photoluminescent silicon nanocrystals are very attractive for biomedical and electronic applications. Here a new process is presented to synthesize photoluminescent silicon nanocrystals with diameters smaller than 6 nm from a porous silicon template. These nanoparticles are formed using a pore-wall thinning approach, where the as-etched porous silicon layer is partially oxidized to silica, which is dissolved by a hydrofluoric acid solution, decreasing the pore-wall thickness. This decrease in pore-wall thickness leads to a corresponding decrease in the size of the nanocrystals that make up the pore walls, resulting in the formation of smaller nanoparticles during sonication of the porous silicon. Particle diameters were measured using dynamic light scattering, and these values were compared with the nanocrystallite size within the pore wall as determined from X-ray diffraction. Additionally, an increase in the quantum confinement effect is observed for these particles through an increase in the photoluminescence intensity of the nanoparticles compared with the as-etched nanoparticles, without the need for a further activation step by oxidation after synthesis.

  2. A Eutectic Melting Study of Double Wall Cladding Tubes of FeCrAl and Zircaloy-4

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Woojin; Son, Seongmin; Lee, You Ho; Lee, Jeong Ik; Ryu, Ho Jin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Jeong, Eun [Kyunghee University, Yongin (Korea, Republic of)

    2015-10-15

    The eutectic melting behavior of FeCrAl/Zircaloy-4 double wall cladding tubes was investigated by annealing at various temperatures ranging from 900 .deg. C to 1300 .deg. C. It was found that significant eutectic melting occurred after annealing at temperatures equal to or higher than 1150 .deg. C. It means that an additional diffusion barrier layer is necessary to limit the eutectic melting between FeCrAl and Zircaloy-4 alloy cladding tubes. Coating of FeCrAl layers on the Zr alloy cladding tube is being investigated for the development of accident tolerant fuel by exploiting of both the oxidation resistance of FeCrAl alloys and the neutronic advantages of Zr alloys. Coating of FeCrAl alloys on Zr alloy cladding tubes can be performed by various techniques including thermal spray, laser cladding, and co-extrusion. Son et al. also reported the fabrication of FeCrAl/Zr ally double wall cladding by the shrink fit method. For the double layered cladding tubes, the thermal expansion mismatch between the dissimilar materials, severe deformation or mechanical failure due to the evolution of thermal stresses can occur when there is a thermal cycling. In addition to the thermal stress problems, chemical compatibilities between the two different alloys should be investigated in order to check the stability and thermal margin of the double wall cladding at a high temperature. Generally, it is considered that Zr alloy cladding will maintain its mechanical integrity up to 1204 .deg. C (2200 .deg. F) to satisfy the acceptance criteria for emergency core cooling systems.

  3. Piezoresistivity of mechanically drawn single-walled carbon nanotube (SWCNT) thin films-: mechanism and optimizing principle

    Science.gov (United States)

    Obitayo, Waris

    The individual carbon nanotube (CNT) based strain sensors have been found to have excellent piezoresistive properties with a reported gauge factor (GF) of up to 3000. This GF on the other hand, has been shown to be structurally dependent on the nanotubes. In contrast, to individual CNT based strain sensors, the ensemble CNT based strain sensors have very low GFs e.g. for a single walled carbon nanotube (SWCNT) thin film strain sensor, GF is ~1. As a result, studies which are mostly numerical/analytical have revealed the dependence of piezoresistivity on key parameters like concentration, orientation, length and diameter, aspect ratio, energy barrier height and Poisson ratio of polymer matrix. The fundamental understanding of the piezoresistive mechanism in an ensemble CNT based strain sensor still remains unclear, largely due to discrepancies in the outcomes of these numerical studies. Besides, there have been little or no experimental confirmation of these studies. The goal of my PhD is to study the mechanism and the optimizing principle of a SWCNT thin film strain sensor and provide experimental validation of the numerical/analytical investigations. The dependence of the piezoresistivity on key parameters like orientation, network density, bundle diameter (effective tunneling area), and length is studied, and how one can effectively optimize the piezoresistive behavior of a SWCNT thin film strain sensors. To reach this goal, my first research accomplishment involves the study of orientation of SWCNTs and its effect on the piezoresistivity of mechanically drawn SWCNT thin film based piezoresistive sensors. Using polarized Raman spectroscopy analysis and coupled electrical-mechanical test, a quantitative relationship between the strain sensitivity and SWCNT alignment order parameter was established. As compared to randomly oriented SWCNT thin films, the one with draw ratio of 3.2 exhibited ~6x increase on the GF. My second accomplishment involves studying the

  4. Developmental evolution of flowering plant pollen tube cell walls: callose synthase (CalS gene expression patterns

    Directory of Open Access Journals (Sweden)

    Abercrombie Jason M

    2011-07-01

    Full Text Available Abstract Background A number of innovations underlie the origin of rapid reproductive cycles in angiosperms. A critical early step involved the modification of an ancestrally short and slow-growing pollen tube for faster and longer distance transport of sperm to egg. Associated with this shift are the predominantly callose (1,3-β-glucan walls and septae (callose plugs of angiosperm pollen tubes. Callose synthesis is mediated by callose synthase (CalS. Of 12 CalS gene family members in Arabidopsis, only one (CalS5 has been directly linked to pollen tube callose. CalS5 orthologues are present in several monocot and eudicot genomes, but little is known about the evolutionary origin of CalS5 or what its ancestral function may have been. Results We investigated expression of CalS in pollen and pollen tubes of selected non-flowering seed plants (gymnosperms and angiosperms within lineages that diverged below the monocot/eudicot node. First, we determined the nearly full length coding sequence of a CalS5 orthologue from Cabomba caroliniana (CcCalS5 (Nymphaeales. Semi-quantitative RT-PCR demonstrated low CcCalS5 expression within several vegetative tissues, but strong expression in mature pollen. CalS transcripts were detected in pollen tubes of several species within Nymphaeales and Austrobaileyales, and comparative analyses with a phylogenetically diverse group of sequenced genomes indicated homology to CalS5. We also report in silico evidence of a putative CalS5 orthologue from Amborella. Among gymnosperms, CalS5 transcripts were recovered from germinating pollen of Gnetum and Ginkgo, but a novel CalS paralog was instead amplified from germinating pollen of Pinus taeda. Conclusion The finding that CalS5 is the predominant callose synthase in pollen tubes of both early-diverging and model system angiosperms is an indicator of the homology of their novel callosic pollen tube walls and callose plugs. The data suggest that CalS5 had transient expression

  5. A drift chamber constructed of aluminized mylar tubes

    International Nuclear Information System (INIS)

    Baringer, P.; Jung, C.; Ogren, H.O.; Rust, D.R.

    1987-01-01

    A thin reliable drift chamber has been constructed to be used near the interaction point of the PEP storage ring in the HRS detector. It is composed of individual drift tubes with aluminized mylar walls. (orig.)

  6. A drift chamber constructed of aluminized mylar tubes

    Science.gov (United States)

    Baringer, P.; Jung, C.; Ogren, H. O.; Rust, D. R.

    1987-03-01

    A thin reliable drift chamber has been constructed to be used near the interaction point of the PEP storage ring in the HRS detector. It is composed of individual drift tubes with aluminized mylar walls.

  7. Removal of Malachite Green Dye from Aqueous Solution Using Multi-Walled Carbon Nano tubes: An Application of Experimental Design

    International Nuclear Information System (INIS)

    Siti Aminah Zulkepli; Md Pauzi Abdullah; Md Pauzi Abdullah; Wan Mohd Afiq Wan Mohd Khalik

    2016-01-01

    An experimental design methodology was performed in the optimization of removal of malachite green dye by multi-walled carbon nano tubes. A Central Composite Design (25) was chosen to develop a mathematical model and determine the optimum condition for adsorption of malachite green by carbon nano tubes. Five experimental factors, namely initial dye concentration, mass of adsorbent, pH, contact time and agitation speed were studied. Maximum adsorption of malachite green was achieved at the suggested optimum conditions: initial dye concentration (20 ppm), weight of adsorbent (0.03 g), pH solution (7) contact time (17 min) and agitation speed (150 strokes per min). The experimental value of adsorption by multi-walled carbon nano tubes were found to be in good agreement with the predicted value (R"2 = 0.922).The experimental equilibrium data were best fitted to isotherm model (Langmuir) and kinetic model (pseudo second-order) respectively. Maximum adsorption by carbon nano tubes at monolayer for malachite green was obtained at 112.36 mg/ g while kinetic rate constant was calculated to be 0.0017 g mg"-"1 min"-"1. (author)

  8. Perspectives of Single-Wall Carbon Nano-tube Production in the Arc Discharge Process

    International Nuclear Information System (INIS)

    Krestinin, A.V.; Kiselev, N.A.; Raevskii, A.V; Ryabenko, A.G.; Zakharov, D.N.; Zvereva, G.I.

    2003-01-01

    Single-wall carbon nano tubes (SWNTs) promise wide applications in many technical fields. As a result purified SWNT material is sold now on the West market at more than 1000 dollars per 1 gram. Thus developing an effective technology for SWNTs production rises to a very important sintofene problem. The perspectives of three existing methods providing raw material in the technology of SWNT production have been analyzed. They are i) pulsed laser evaporation of graphite/metal composites, ii) evaporation of graphite electrodes with metal content in the are discharge process, and iii) catalytic decomposition of the mixture of CO and metal carbonyl catalyst precursor. The observed dynamites of SWNT market points to replacing the laser method of SWNTs production by the are process. The conclusion has been made that the technology based on the are process will be the major one for the fabrication of purified SWNTs at least for the next five years. A reliable estimation of a low price limit of SWNTs was derived from a comparison of two technologies based on the are discharge process: the first one is the production of SWNTs and the second one is the production of a fullerene mixture C 6 0 + C 7 0. The main conclusion was made that the price of purified SWNTs should always be more by 2-3 times the price of fullerene mixture. The parameters of a lab-scale technology for the production of purified SWNTs are listed. A large-scale application of the developed technology is expected to reduce the price of purified SWNTs by approximately ten times. The methods now employed for the characterization of products containing SWNTs are briefly observed. It is concluded that electron microscopy, thermogravimetric analysis, absorption and Raman spectroscopy, measurement of the specific surface aria, optical microscopy - each in separation is not enough for extensive characterization of a sample containing SWNTs, and all these methods should be used together. (author)

  9. Uptake of gaseous formaldehyde onto soil surfaces: a coated-wall flow tube study

    Science.gov (United States)

    Li, Guo; Su, Hang; Li, Xin; Meusel, Hannah; Kuhn, Uwe; Pöschl, Ulrich; Shao, Min; Cheng, Yafang

    2015-04-01

    Gaseous formaldehyde (HCHO) is an important intermediate molecule and source of HO2 radicals. However, discrepancies exist between model simulated and observed HCHO concentrations, suggesting missing sources or sinks in the HCHO budget. Multiphase processes on the surface of soil and airborne soil-derived particles have been suggested as an important mechanism for the production/removal of atmospheric trace gases and aerosols. In this work, the uptake of gaseous HCHO on soil surfaces were investigated through coated-wall flow tube experiments with HCHO concentration ranging from 10 to 40 ppbv. The results show that the adsorption of HCHO occurred on soil surfaces, and the uptake coefficient dropped gradually (i.e., by a factor of 5 after 1 hour) as the reactive surface sites were consumed. The HCHO uptake coefficient was found to be affected by the relative humidity (RH), decreasing from (2.4 ± 0.5) × 10-4 at 0% RH to (3.0 ± 0.08) × 10-5 at 70% RH, due to competition of water molecule absorption on the soil surface. A release of HCHO from reacted soil was also detected by applying zero air, suggesting the nature of reversible physical absorption and the existence of an equilibrium at the soil-gas interface. It implies that soil could be either a source or a sink for HCHO, depending on the ambient HCHO concentration. We also develop a Matlab program to calculate the uptake coefficient under laminar flow conditions based on the Cooney-Kim-Davis method.

  10. Local conductivity and the role of vacancies around twin walls of (001)-BiFeO3 thin films

    NARCIS (Netherlands)

    Farokhipoor, S.; Noheda, Beatriz

    2012-01-01

    BiFeO3 thin films epitaxially grown on SrRuO3-buffered (001)-oriented SrTiO3 substrates show orthogonal bundles of twin domains, each of which contains parallel and periodic 71 degrees domain walls. A smaller amount of 109 degrees domain walls are also present at the boundaries between two adjacent

  11. Evaluation on double-wall-tube residual stress distribution of sodium-heated steam generator by neutron diffraction and numerical analysis

    International Nuclear Information System (INIS)

    Kisohara, N.; Suzuki, H.; Akita, K.; Kasahara, N.

    2012-01-01

    A double-wall-tube is nominated for the steam generator heat transfer tube of future sodium fast reactors (SFRs) in Japan, to decrease the possibility of sodium/water reaction. The double-wall-tube consists of an inner tube and an outer tube, and they are mechanically contacted to keep the heat transfer of the interface between the inner and outer tubes by their residual stress. During long term SG operation, the contact stress at the interface gradually falls down due to stress relaxation. This phenomenon might increase the thermal resistance of the interface and degrade the tube heat transfer performance. The contact stress relaxation can be predicted by numerical analysis, and the analysis requires the data of the initial residual stress distributions in the tubes. However, unclear initial residual stress distributions prevent precious relaxation evaluation. In order to resolve this issue, a neutron diffraction method was employed to reveal the tri-axial (radius, hoop and longitudinal) initial residual stress distributions in the double-wall-tube. Strain gauges also were used to evaluate the contact stress. The measurement results were analyzed using a JAEA's structural computer code to determine the initial residual stress distributions. Based on the stress distributions, the structural computer code has predicted the transition of the relaxation and the decrease of the contact stress. The radial and longitudinal temperature distributions in the tubes were input to the structural analysis model. Since the radial thermal expansion difference between the inner (colder) and outer (hotter) tube reduces the contact stress and the tube inside steam pressure contributes to increasing it, the analytical model also took these effects into consideration. It has been conduced that the inner and outer tubes are contacted with sufficient stresses during the plant life time, and that effective heat transfer degradation dose not occur in the double-wall-tube SG. (authors)

  12. Effect of local wall thinning on the collapse behavior of pipe elbows subjected to a combined internal pressure and in-plane bending load

    International Nuclear Information System (INIS)

    Kim, Jin-Weon; Na, Man-Gyun; Park, Chi-Yong

    2008-01-01

    The objective of this study was to investigate the effect of local wall thinning on the collapse behavior of pipe elbows subjected to a combined internal pressure and in-plane bending load. This study evaluated the global deformation behavior and collapse moment of the elbows, which contained various types of local wall-thinning defects at their intrados or extrados, using three-dimensional elastic-plastic finite element analysis. The analysis results showed that the global deformation behavior of locally wall-thinned elbows was largely governed by the mode of the bending and the elbow geometry rather than the wall-thinning parameters, except for elbows with considerably large and deep wall thinning that showed plastic instabilities induced by local buckling and plastic collapsing in the thinned area. The reduction in the collapse moment with wall-thinning depth was considerable when local buckling occurred in the thinned areas, whereas the effect of the thinning depth was small when ovalization occurred. The effects of the circumferential thinning angle and thinning length on the collapse moment of elbows were not major for shallow wall-thinning cases. For deeper wall-thinning cases, however, their effects were significant and the dependence of collapse moment on the axial thinning length was governed by the stress type applied to the wall-thinned area. Typically, the reduction in the collapse moment due to local wall thinning was clearer when the thinning defect was located at the intrados rather than the extrados, and it was apparent for elbows with larger bend radius

  13. Fluid-structure-interaction analysis for welded pipes with flow-accelerated corrosion wall thinning

    Energy Technology Data Exchange (ETDEWEB)

    Sun, L.; Ding, Y., E-mail: lan.sun@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2016-06-15

    The flow-accelerated corrosion (FAC) entrance effect results in enhanced wall thinning immediately downstream of a weld if the weld connects an upstream FAC-resistant material with a downstream less resistant material. The weld regions, especially those with local repairs, are susceptible to cracking due to the high residual stresses induced by fabrication. The combined effects of the FAC entrance effect and high stresses at a weld might compromise the structural integrity of the piping and lead to a failure. Weld degradation by FAC entrance effect has been observed at nuclear and fossil power plants. This paper describes an application using fluid-structure-interaction (FSI) modelling to study the combined effects of FAC wall thinning, weld residual stresses, and in-service loads on welded structures. Simplified cases analyzed were based on CANDU outlet feeder conditions. The analysis includes the flow and mass transfer modelling of the FAC entrance effect using computational fluid dynamics (CFD) and nonlinear structural analyses of the welded structures with wall thinning and an assumed weld residual stress and strain distribution. The FSI analyses were performed using ANSYS Workbench, an integrated platform that enables the coupling of CFD and structural analysis solutions. The obtained results show that the combination of FAC, weld residual stresses, in-service loads (including the internal pressure) and (or) extreme loads could cause high stresses and affect the integrity of the welded pipes. The present work demonstrated that the FSI modelling can be used as an effective approach to assess the integrity of welded structures. (author)

  14. Development of carbon steel with superior resistance to wall thinning and fracture for nuclear piping system

    International Nuclear Information System (INIS)

    Rhee, Chang Kyu; Lee, Min Ku; Park, Jin Ju

    2010-07-01

    Carbon steel is usually used for piping for secondary coolant system in nuclear power plant because of low cost and good machinability. However, it is generally reported that carbon steel was failed catastrophically because of its low resistance to wall thinning and fracture toughness. Especially, flow accelerated corrosion (FAC) is one of main problems of the wall thinning of piping in the nuclear power plant. Therefore, in this project, fabrication technology of new advanced carbon steel materials modified by dispersion of nano-carbide ceramics into the matrix is developed first in order to improve the resistance to wall thinning and fracture toughness drastically compared to the conventional one. In order to get highly wettable fine TiC ceramic particles into molten metal, the micro-sized TiC particles were first mechanically milled by Fe (MMed TiC/Fe) in a high energy ball mill machine in Ar gas atmosphere, and then mixed with surfactant metal elements (Sn, Cr, Ni) to obtain better wettability, as this lowered surface tension of the carbon steel melt. According to microscopic images revealed that an addition of MMed TiC/Fe-surfactant mixed powders favorably disperses the fine TiC particles in the carbon steel matrix. It was also found that the grain size refinement of the cast matrix is achieved remarkably when fine TiC particles were added due to the fact that they act as nucleation sites during the solidification process. As a results, a cast carbon steel dispersed with fine TiC particles shows improved mechanical properties such as hardness, tensile strength and cavitation resistance compared to that of without particles. However, the slight decrease of toughness was found

  15. Nonlinear mechanics of thin-walled structures asymptotics, direct approach and numerical analysis

    CERN Document Server

    Vetyukov, Yury

    2014-01-01

    This book presents a hybrid approach to the mechanics of thin bodies. Classical theories of rods, plates and shells with constrained shear are based on asymptotic splitting of the equations and boundary conditions of three-dimensional elasticity. The asymptotic solutions become accurate as the thickness decreases, and the three-dimensional fields of stresses and displacements can be determined. The analysis includes practically important effects of electromechanical coupling and material inhomogeneity. The extension to the geometrically nonlinear range uses the direct approach based on the principle of virtual work. Vibrations and buckling of pre-stressed structures are studied with the help of linearized incremental formulations, and direct tensor calculus rounds out the list of analytical techniques used throughout the book. A novel theory of thin-walled rods of open profile is subsequently developed from the models of rods and shells, and traditionally applied equations are proven to be asymptotically exa...

  16. A Study on Effect of Local Wall Thinning in Carbon Steel Elbow Pipe on Elastic Stress Concentration

    International Nuclear Information System (INIS)

    Kim, Jong Sung; Seo, Jae Seok

    2009-01-01

    Feeder pipes that connect the inlet and outlet headers to the reactor core in CANDU nuclear power plants are considered as safety Class 1 piping items. Therefore, fatigue of feeder pipes should be assessed at design stage in order to verify structural integrity during design lifetime. In accordance with the fatigue assessment result, cumulative usage factors of some feeder pipes have significant values. The feeder pipes made of SA-106 Grade B or C carbon steel have some elbows and bends. An active degradation mechanism for the carbon steel outlet feeder piping is local wall thinning due to flow-accelerated corrosion. Inspection results from plants and metallurgical examinations of removed feeders indicated the presence of localized thinning in the vicinity of the welds in the lower portion of outlet feeders, such as Grayloc hub-to-bend weld, Grayloc hub-to-elbow weld, elbow-to-elbow, and elbow-to-pipe weld. This local wall thinning can cause increase of peak stress due to stress concentration by notch effect. The increase of peak stress results in increase of cumulative usage factor. However, present fatigue assessment doesn't consider the stress concentration due to local wall-thinning. Therefore, it is necessary to assess the effect of local wall thinning on stress concentration. This study investigates the effect of local wall thinning geometry on stress concentration by performing finite element elastic stress analysis

  17. Fuel retention properties of thin-wall glass target in low temperature

    International Nuclear Information System (INIS)

    Gao Dangzhong; Huang Yong; Tang Yongjian; Wen Shuhuai

    2001-01-01

    In room temperature the fuel gas storage half-life of the thin-wall (wall-thickness less than 1μm) glass microsphere is only a few days, it is difficult to be used for ICF. To efficiently prolong the half-life of such type targets, and meet the need of ICF experiments, the special device for storing the targets was developed. All the targets are immerged in liquid-nitrogen (LN 2 ), after being sealed in vacuum. During this period the change of Si 1.74 keV X-ray counts were measured a few times with the low energy X-ray multi-channel analyzer. The results of experiment indicate that, in the environment of -196 degree C, the fuel storage half-life of target has been successfully extended to 100-300 d from 3-10 d. However, the surface roughness of target was not obviously changed

  18. Thin wall ductile iron casting as a substitute for aluminum alloy casting in automotive industry

    Directory of Open Access Journals (Sweden)

    M. Górny

    2009-01-01

    Full Text Available In paper it is presented thin wall ductile iron casting (TWDI as a substitute of aluminium alloy casting. Upper control arm made of ductile iron with wall thickness ranging from 2 – 3.7 mm was produced by inmold process. Structure, mechanical properties and computer simulations were investigated. Structural analysis of TWDI shows pearlitic-ferritic matrix free from chills and porosity. Mechanical testing disclose superior ultimate tensile strength (Rm, yield strength (Rp0,2 and slightly lower elongation (E of TWDI in comparison with forged control arm made of aluminium alloy (6061-T6. Moreover results of computer simulation of static loading for tested control arms are presented. Analysis show that the light-weight ductile iron casting can be loaded to similar working conditions as the forged Al alloy without any potential failures.

  19. An improved thin film brick-wall model of black hole entropy

    CERN Document Server

    Liu Wen Biao

    2001-01-01

    The authors improve the brick-wall model to take only the contribution of a thin film near the event horizon into account. This improvement not only gives them a satisfactory result, but also avoids some drawbacks in the original brick-wall method such as the little mass approximation, neglecting logarithm term, and taking the term L/sup 3/ as the contribution of the vacuum surrounding a black hole. It is found that there is an intrinsic relation between the event horizon and the entropy. The event horizon is the characteristic of a black hole, so the entropy calculating of a black hole is also naturally related to its horizon. (12 refs).

  20. Laser and Pressure Resistance Weld of Thin-Wall Cladding for LWR Accident-Tolerant Fuels

    Science.gov (United States)

    Gan, J.; Jerred, N.; Perez, E.; Haggard, D. C.

    2018-02-01

    FeCrAl alloy with typical composition of approximately Fe-15Cr-5Al is considered a primary candidate cladding material for light water reactor accident-tolerant fuel because of its superior resistance to oxidation in high-temperature steam compared with Zircaloy cladding. Thin-walled FeCrAl cladding at 350 μm wall thickness is required, and techniques for joining endplug to cladding need to be developed. Fusion-based laser weld and solid-state joining with pressure resistance weld were investigated in this study. The results of microstructural characterization, mechanical property evaluation by tensile testing, and hydraulic pressure burst testing of the welds for the cladding-endplug specimen are discussed.

  1. Development of laser cladding technology for maintenance of pipe wall thinning

    International Nuclear Information System (INIS)

    Terada, Takaya; Nishimura, Akihiko; Oka, Kiyoshi

    2011-01-01

    We are developing the laser welding and cladding device for the maintenance of heat exchanger pipes. In the case of flow accelerated corrosion where pipe wall thinning occurred after a long time operation, laser cladding is mostly expected. A laser processing head was proposed in order to access the pipe wall. A composite-type optical fiber scope was used for real time observation and laser processing. An air-cooled compact fiber laser was used for spot heating. We present the concept of the laser cladding device which have the following features: 1) Wire feeding modules, 2) Module capable of laser irradiation in the vertical heat exchanger pipe, 3) Assist gas injection module. (author)

  2. Cellular automaton modeling of ductile iron microstructure in the thin wall

    Directory of Open Access Journals (Sweden)

    A.A. Burbelko

    2011-10-01

    Full Text Available The mathematical model of the globular eutectic solidification in 2D was designed. Proposed model is based on the Cellular Automaton Finite Differences (CA-FD calculation method. Model has been used for studies of the primary austenite and of globular eutectic grains growth during the solidification of the ductile iron with different carbon equivalent in the thin wall casting. Model takes into account, among other things, non-uniform temperature distribution in the casting wall cross-section, kinetics of the austenite and graphite grains nucleation, and non-equilibrium nature of the interphase boundary migration. Solidification of the DI with different carbon equivalents was analyzed. Obtained results were compared with the solidification path calculated by CALPHAD method.

  3. A thin-walled pressurized sphere exposed to external general corrosion and nonuniform heating

    Science.gov (United States)

    Sedova, Olga S.; Pronina, Yulia G.; Kuchin, Nikolai L.

    2018-05-01

    A thin-walled spherical shell subjected to simultaneous action of internal and external pressure, nonuniform heating and outside mechanochemical corrosion is considered. It is assumed that the shell is homogeneous, isotropic and linearly elastic. The rate of corrosion is linearly dependent on the equivalent stress, which is the sum of mechanical and temperature stress components. Paper presents a new analytical solution, which takes into account the effect of the internal and external pressure values themselves, not only their difference. At the same time, the new solution has a rather simple form as compared to the results based on the solution to the Lame problem for a thick-walled sphere under pressure. The solution obtained can serve as a benchmark for numerical analysis and for a qualitative forecast of durability of the vessel.

  4. Influence of circumferential flaw length on internal burst pressure of a wall-thinned pipe

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Masataka, E-mail: tsuji-m@u-fukui.ac.jp [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui, Fukui (Japan); Meshii, Toshiyuki [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui, Fukui (Japan)

    2013-02-15

    Highlights: ► The effect of θ on p{sub f} was examined by experimental analysis and FEA. ► Here θ is the circumferential angle of a flaw, p{sub f} is the internal burst pressure. ► p{sub f} decreased as θ increased in some cases. ► The effect of θ on p{sub f} should be taken into consideration in evaluating p{sub f}. -- Abstract: This paper examines the effect of the circumferential angle of a flaw θ on the internal burst pressure p{sub f} of pipes with artificial wall-thinned flaws. The effect of θ has conventionally been regarded as unimportant in the evaluation of the p{sub f} of wall-thinned straight pipes. Therefore, a burst pressure equation for an axial crack inside a cylinder (Fig. 1, left), such as Kiefner's equation (Kiefner et al., 1973), has been widely applied (ANSI/ASME B31.G., 1991; Hasegawa et al., 2011). However, the following implicit assumptions notably exist when applying the equation to planar flaws in situations with non-planar flaws. 1)The fracture mode of the non-planar flaw under consideration is identical to that of the crack. 2)The effect of θ on p{sub f}, which is not considered for an axial crack, is small or negligible. However, the experimental results from the systematic burst tests for carbon steel pipes with artificial wall-thinned flaws examined in this paper showed that these implicit assumptions may be incorrect. In this paper the experimental results are evaluated in further detail. The purpose of the evaluation was to clarify the effect of θ on p{sub f}. Specifically, the significance of the flaw configuration (axial length δ{sub z} and wall-thinning ratio t{sub 1}/t) was studied for its effects on θ and p{sub f}. In addition, a simulation of this effect was conducted using a large strain elastic-plastic Finite Element Analysis (FEA) model. As observed from the experimental results, θ tended to affect p{sub f} in cases with large δ{sub z}, and t{sub 1}/t was also correlated with a decrease in p{sub f

  5. Numerical simulation of instability behaviour of thin-walled frames with flexible connections

    International Nuclear Information System (INIS)

    Turkalj, G.; Brnic, J.; Vizentin, G.; Lanc, D.

    2009-01-01

    A one-dimensional finite element formulation for numerical simulation of instability behaviour of thin-walled frames containing flexible connections is presented. Stiffness matrices of a conventional 14-degree of freedom beam element are derived by applying the linearized virtual work principle and Vlasov's assumption. The structural material is assumed to be homogeneous, isotropic and linear-elastic. Flexible connection behaviour and different warping deformation conditions are introduced into the numerical model by modifying stiffness matrices of a conventional beam element. For that purpose a special transformation matrix is derived. The effectiveness of the numerical algorithm discussed is validated through the test problem

  6. Acoustic emission monitoring during hydrotests of a thin wall pressure vessel

    International Nuclear Information System (INIS)

    Fontana, E.; Grugni, G.; Panzani, C.; Pirovano, B.; Possa, G.; Tonolini, F.

    1975-01-01

    The results are presented of an acoustic emission monitoring performed during hydrotests of a thin wall steel pressure vessel. The location of acoustic sources was based on longitudinal wave front detection. The careful calibration of the three sensors instrumentation system used for acoustic source location was found to be useful, and alllowed an accurate location error analysis. Acoustic emission in the hydrotests was found to be mainly due to stress release in weld seams. (Fontana, E.; Grugni, G.; Panzani, C.; Pirovano, B.; Possa, G.; Tonolini, F.)

  7. Analytical Investigation of Elastic Thin-Walled Cylinder and Truncated Cone Shell Intersection Under Internal Pressure.

    Science.gov (United States)

    Zamani, J; Soltani, B; Aghaei, M

    2014-10-01

    An elastic solution of cylinder-truncated cone shell intersection under internal pressure is presented. The edge solution theory that has been used in this study takes bending moments and shearing forces into account in the thin-walled shell of revolution element. The general solution of the cone equations is based on power series method. The effect of cone apex angle on the stress distribution in conical and cylindrical parts of structure is investigated. In addition, the effect of the intersection and boundary locations on the circumferential and longitudinal stresses is evaluated and it is shown that how quantitatively they are essential.

  8. Manufacturing of thin-walled parts for machinery by selective laser melting

    Directory of Open Access Journals (Sweden)

    Bobyr Vitaliy

    2017-01-01

    Full Text Available The paper describes the technology of selective laser melting, as well as its capabilities in the manufacture of thin-wall honeycomb energy absorber (HEA. The effect of the technological parameters of the building process on the HEA walls’ thickness is studied. Conformity analysis of the mass-dimensional characteristics of the finished composition with the predefined parameters of the 3D-CAD model is carried out. Dependencies of building parameterson the quality of the manufactured HEA are established, general recommendations for the practical use of technology in the creation of HEAare given.

  9. Strength and Stability Analysis of a Single Walled Black Phosphorus Tube under Axial Compression

    OpenAIRE

    Cai, Kun; Wan, Jing; Wei, Ning; Qin, Qinghua

    2016-01-01

    Few-layered black phosphorus materials recently attract much attention due to its special electronic properties. As a Consequence, the nano-tube from a single-layer black phosphorus has been theoretically built. The corresponding electronic properties of such black phosphorus nano-tube were also evaluated numerically.

  10. Methods of Investigation of Equations that Describe Waves in Tubes with Elastic Walls and Application of the Theory of Reversible and Weak Dissipative Shocks

    Science.gov (United States)

    Bakholdin, Igor

    2018-02-01

    Various models of a tube with elastic walls are investigated: with controlled pressure, filled with incompressible fluid, filled with compressible gas. The non-linear theory of hyperelasticity is applied. The walls of a tube are described with complete membrane model. It is proposed to use linear model of plate in order to take the bending resistance of walls into account. The walls of the tube were treated previously as inviscid and incompressible. Compressibility of material of walls and viscosity of material, either gas or liquid are considered. Equations are solved numerically. Three-layer time and space centered reversible numerical scheme and similar two-layer space reversible numerical scheme with approximation of time derivatives by Runge-Kutta method are used. A method of correction of numerical schemes by inclusion of terms with highorder derivatives is developed. Simplified hyperbolic equations are derived.

  11. The role of the velocity gradient in laminar convective heat transfer through a tube with a uniform wall heat flux

    International Nuclear Information System (INIS)

    Wang Liangbi; Zhang Qiang; Li Xiaoxia

    2009-01-01

    This paper aims to contribute to a better understanding of convective heat transfer. For this purpose, the reason why thermal diffusivity should be placed before the Laplacian operator of the heat flux, and the role of the velocity gradient in convective heat transfer are analysed. The background to these analyses is that, when the energy conservation equation of convective heat transfer is used to explain convective heat transfer there are two points that are difficult for teachers to explain and for undergraduates to understand: thermal diffusivity is placed before the Laplacian operator of temperature; on the wall surface (the fluid side) the velocity is zero, a diffusion equation of temperature is gained from energy conservation equation, however, temperature cannot be transported. Consequently, the real physical meaning of thermal diffusivity is not clearly reflected in the energy conservation equation, and whether heat transfer occurs through a diffusion process or a convection process on the wall surface is not clear. Through a simple convective heat transfer case: laminar convective heat transfer in a tube with a uniform wall heat flux on the tube wall, this paper explains these points more clearly. The results declare that it is easier for teachers to explain and for undergraduates to understand these points when a description of heat transfer in terms of the heat flux is used. In this description, thermal diffusivity is placed before the Laplacian operator of the heat flux; the role of the velocity gradient in convective heat transfer appears, on the wall surface, the fact whether heat transfer occurs through a diffusion process or a convection process can be explained and understood easily. The results are not only essential for teachers to improve the efficiency of university-level physics education regarding heat transfer, but they also enrich the theories for understanding heat transfer

  12. Failure probability assessment of wall-thinned nuclear pipes using probabilistic fracture mechanics

    International Nuclear Information System (INIS)

    Lee, Sang-Min; Chang, Yoon-Suk; Choi, Jae-Boong; Kim, Young-Jin

    2006-01-01

    The integrity of nuclear piping system has to be maintained during operation. In order to maintain the integrity, reliable assessment procedures including fracture mechanics analysis, etc., are required. Up to now, this has been performed using conventional deterministic approaches even though there are many uncertainties to hinder a rational evaluation. In this respect, probabilistic approaches are considered as an appropriate method for piping system evaluation. The objectives of this paper are to estimate the failure probabilities of wall-thinned pipes in nuclear secondary systems and to propose limited operating conditions under different types of loadings. To do this, a probabilistic assessment program using reliability index and simulation techniques was developed and applied to evaluate failure probabilities of wall-thinned pipes subjected to internal pressure, bending moment and combined loading of them. The sensitivity analysis results as well as prototypal integrity assessment results showed a promising applicability of the probabilistic assessment program, necessity of practical evaluation reflecting combined loading condition and operation considering limited condition

  13. Wall thinning trend analyses for secondary side piping of Korean NPPs

    International Nuclear Information System (INIS)

    Hwang, K.M.; Jin, T.E.; Lee, S.H.; Jeon, S.C.

    2003-01-01

    Since the mid-1990s, nuclear power plants in Korea have experienced wall thinning, leaks, and ruptures of secondary side piping caused by flow-accelerated corrosion (FAC). The pipe failures have increased as operating time progresses. In order to prevent the FAC-induced pipe failures and to develop an effective FAC management strategy, KEPRI and KOPEC have conducted a study for developing systematic FAC management technology for secondary side piping of all Korean nuclear power plants. As a part of the study, FAC analyses were performed using the CHECWORKS code. The analysis results were used to select components for inspection and to determine inspection intervals on each nuclear power plant. This paper describes the introduction of the FAC analysis method and the wall thinning trend analysis results by reactor type, system, and water treatment amine. This paper also represents the site application feasibility for secondary side piping management. The site application feasibility of the analysis results was proven by comparisons of predicted and measured wear rates. (author)

  14. Estimation of collapse moment for the wall-thinned pipe bends using fuzzy model identification

    International Nuclear Information System (INIS)

    Na, Man Gyun; Kim, Jin Weon; Hwang, In Joon

    2006-01-01

    In this work, the collapse moment due to wall-thinned defects is estimated through fuzzy model identification. A subtractive clustering method is used as the basis of a fast and robust algorithm for identifying the fuzzy model. The fuzzy model is optimized by a genetic algorithm combined with a least squares method. The developed fuzzy model has been applied to the numerical data obtained from the finite element analysis. Principal component analysis is used to preprocess the input signals into the fuzzy model to reduce the sensitivity to the input change and the fuzzy model are trained by using the data set prepared for training (training data) and verified by using another data set different (independent) from the training data. Also, three fuzzy models are trained, respectively, for three data sets divided into the three classes of extrados, intrados, and crown defects, which is because they have different characteristics. The relative root mean square (RMS) errors of the estimated collapse moment are 0.5397% for the training data and 0.8673% for the test data. It is known from this result that the fuzzy models are sufficiently accurate to be used in the integrity evaluation of wall-thinned pipe bends and elbows

  15. Estimation of Collapse Moment for Wall Thinned Elbows Using Fuzzy Neural Networks

    International Nuclear Information System (INIS)

    Na, Man Gyun; Kim, Jin Weon; Shin, Sun Ho; Kim, Koung Suk; Kang, Ki Soo

    2004-01-01

    In this work, the collapse moment due to wall-thinning defects is estimated by using fuzzy neural networks. The developed fuzzy neural networks have been applied to the numerical data obtained from the finite element analysis. Principal component analysis is used to preprocess the input signals into the fuzzy neural network to reduce the sensitivity to the input change and the fuzzy neural networks are trained by using the data set prepared for training (training data) and verified by using another data set different (independent) from the training data. Also, two fuzzy neural networks are trained for two data sets divided into the two classes of extrados and intrados defects, which is because they have different characteristics. The relative 2-sigma errors of the estimated collapse moment are 3.07% for the training data and 4.12% for the test data. It is known from this result that the fuzzy neural networks are sufficiently accurate to be used in the wall-thinning monitoring of elbows

  16. Tunable Gas Permeability of Polymer-Clay Nano Brick Wall Thin Film Assemblies

    Science.gov (United States)

    Gamboa, Daniel; Priolo, Morgan; Grunlan, Jaime

    2010-03-01

    Thin films of anionic natural montmorrilonite (MMT) clay and cationic polyethylenimine (PEI) have been produced by alternately dipping a plastic substrate into dilute aqueous mixtures containing each ingredient. After 40 polymer-clay layers have been deposited, the resulting transparent film exhibits an oxygen transmission rate (OTR) below 0.35 cm^3/m^2 . day when the pH of PEI solution is 10. This low permeability is due to a brick wall nanostructure comprised of completely exfoliated clay bricks in polymeric mortar. This brick wall creates an extremely tortuous path at thicknesses below 250 nm and clay concentration above 80 wt%. A 70-bilayer PEI-MMT assembly has an undetectable OTR (< 0.005 cm^3/m^2 . day), which equates to a permeability below SiOx when multiplied by its film thickness of 231 nm. With optical transparency greater than 86% and the ability to be microwaved, these thin film composites are good candidates for flexible electronics packaging and foil replacement for food.

  17. Magnetic moment jumps in flat and nanopatterned Nb thin-walled cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Tsindlekht, M.I., E-mail: mtsindl@vms.huji.ac.il [The Racah Institute of Physics, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Genkin, V.M.; Felner, I.; Zeides, F.; Katz, N. [The Racah Institute of Physics, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Gazi, Š.; Chromik, Š. [The Institute of Electrical Engineering SAS, Dúbravská cesta 9, 84104 Bratislava (Slovakia); Dobrovolskiy, O.V. [Physikalisches Institut, Goethe University, 60438 Frankfurt am Main (Germany); Physics Department, V. Karazin Kharkiv National University, 61077 Kharkiv (Ukraine); Sachser, R.; Huth, M. [Physikalisches Institut, Goethe University, 60438 Frankfurt am Main (Germany)

    2017-02-15

    Highlights: • Magnetization curves of as-prepared and patterned thin-walled cylinders were measured in magnetic fields applied parallel to cylinders axis. • Magnetic moment jumps were observed in magnetic fields lower and above Hc1. • Critical current density in isthmus between two antidots is higher than in a film itself. - Abstract: Penetration of magnetic flux into hollow superconducting cylinders is investigated by magnetic moment measurements. The magnetization curves of a flat and a nanopatterned thin-walled superconducting Nb cylinders with a rectangular cross section are reported for the axial field geometry. In the nanopatterned sample, a row of micron-sized antidots (holes) was milled in the film along the cylinder axis. Magnetic moment jumps are observed for both samples at low temperatures for magnetic fields not only above H{sub c1}, but also in fields lower than H{sub c1}, i. e., in the vortex-free regime. The positions of the jumps are not reproducible and they change from one experiment to another, resembling vortex lattice instabilities usually observed for magnetic fields larger than H{sub c1}. At temperatures above 0.66T{sub c} and 0.78T{sub c} the magnetization curves become smooth for the patterned and the as-prepared sample, respectively. The magnetization curve of a reference flat Nb film in the parallel field geometry does not exhibit jumps in the entire range of accessible temperatures.

  18. Research of precise pulse plasma arc powder welding technology of thin-walled inner hole parts

    Institute of Scientific and Technical Information of China (English)

    Li Zhanming; Du Xiaokun; Sun Xiaofeng; Song Wei

    2017-01-01

    The inner hole parts played an oriented or supporting role in engineering machinery and equipment,which are prone to appear surface damages such as wear,strain and corrosion.The precise pulse plasma arc powder welding method is used for surface damage repairing of inner hole parts in this paper.The working principle and process of the technology are illustrated,and the microstructure and property of repairing layer by precise pulse plasma powder welding and CO2 gas shielded welding are tested and observed by microscope,micro hardness tester and X-ray residual stress tester etc.Results showed that the substrate deformation of thin-walled inner hole parts samples by precise pulse plasma powder welding is relatively small.The repair layer and substrate is metallurgical bonding,the transition zones (including fusion zone and heat affected zone) are relatively narrow and the welding quality is good.h showed that the thin-walled inner hole parts can be repaired by this technology and equipment.

  19. Material Behavior Based Hybrid Process for Sheet Draw-Forging Thin Walled Magnesium Alloys

    International Nuclear Information System (INIS)

    Sheng, Z.Q.; Shivpuri, R.

    2005-01-01

    Magnesium alloys are conventionally formed at the elevated temperatures. The thermally improved formability is sensitive to the temperature and strain rate. Due to limitations in forming speeds, tooling strength and narrow processing windows, complex thin walled parts cannot be made by traditional warm drawing or hot forging processes. A hybrid process, which is based on the deformation mechanism of magnesium alloys at the elevated temperature, is proposed that combines warm drawing and hot forging modes to produce an aggressive geometry at acceptable forming speed. The process parameters, such as temperatures, forming speeds etc. are determined by the FEM modeling and simulation. Sensitivity analysis under the constraint of forming limits of Mg alloy sheet material and strength of tooling material is carried out. The proposed approach is demonstrated on a conical geometry with thin walls and with bottom features. Results show that designed geometry can be formed in about 8 seconds, this cannot be formed by conventional forging while around 1000s is required for warm drawing. This process is being further investigated through controlled experiments

  20. Thin-Walled CFST Columns for Enhancing Seismic Collapse Performance of High-Rise Steel Frames

    Directory of Open Access Journals (Sweden)

    Yongtao Bai

    2017-01-01

    Full Text Available This paper numerically studied the collapse capacity of high-rise steel moment-resisting frames (SMRFs using various width-to-thickness members subjected to successive earthquakes. It was found that the long-period component of earthquakes obviously correlates with the first-mode period of high-rises controlled by the total number of stories. A higher building tends to produce more significant component deterioration to enlarge the maximum story drift angle at lower stories. The width-to-thickness ratio of beam and column components overtly affects the collapse capacity when the plastic deformation extensively develops. The ratio of residual to maximum story drift angle is significantly sensitive to the collapse capacity of various building models. A thin-walled concrete filled steel tubular (CFST column is proposed as one efficient alternative to enhance the overall stiffness and deformation capacity of the high-rise SMRFs with fragile collapse performance. With the equivalent flexural stiffness, CFST-MRF buildings with thin-walled members demonstrate higher capacity to avoid collapse, and the greater collapse margin indicates that CFST-MRFs are a reasonable system for high-rises in seismic prone regions.

  1. Dynamic analysis of horizontal axis wind turbine by thin-walled beam theory

    Science.gov (United States)

    Wang, Jianhong; Qin, Datong; Lim, Teik C.

    2010-08-01

    A mixed flexible-rigid multi-body mathematical model is applied to predict the dynamic performance of a wind turbine system. Since the tower and rotor are both flexible thin-walled structures, a consistent expression for their deformations is applied, which employs a successive series of transformations to locate any point on the blade and tower relative to an inertial coordinate system. The kinetic and potential energy terms of each flexible body and rigid body are derived for use in the Lagrange approach to formulate the wind turbine system's governing equation. The mode shapes are then obtained from the free vibration solution, while the distributions of dynamic stress and displacement of the tower and rotor are computed from the forced vibration response analysis. Using this dynamic model, the influence of the tower's stiffness on the blade tip deformation is studied. From the analysis, it is evident that the proposed model not only inherits the simplicity of the traditional 1-D beam element, but also able to provide detailed information about the tower and rotor response due to the incorporation of the flexible thin-walled beam theory.

  2. Improvement of C*-integral and Crack Opening Displacement Estimation Equations for Thin-walled Pipes with Circumferential Through-wall Cracks

    International Nuclear Information System (INIS)

    Park, Jeong Soon; Jhung, Myung Jo

    2012-01-01

    Since the LBB(Leak-Before-Break) concept has been widely applied to high energy piping systems in the pressurized water reactors, a number of engineering estimation methods had been developed for J-integral and COD values. However, those estimation methods were mostly reliable for relatively thick-walled pipes about R m /t=5 or 10. As the LBB concept might be considered in the design stage of the SFR (Sodium-cooled Fast Reactor) which has relatively thin-walled pipes due to its low design pressure, the applicability of current estimation methods should be investigated for thin-walled pipes. Along with the J-integral and COD, the estimation method for creep fracture mechanics parameters, C*- integral and COD rate, is required because operating temperature of SFR is high enough to induce creep in the structural materials. In this study, the applicability of the current C*- integral and COD estimation methods to thin-walled pipes is studied for a circumferential through-wall crack using the finite element (FE) method. Based on the FE results, enhancement of the current estimation methods is made

  3. Investigation into the influence of laser energy input on selective laser melted thin-walled parts by response surface method

    Science.gov (United States)

    Liu, Yang; Zhang, Jian; Pang, Zhicong; Wu, Weihui

    2018-04-01

    Selective laser melting (SLM) provides a feasible way for manufacturing of complex thin-walled parts directly, however, the energy input during SLM process, namely derived from the laser power, scanning speed, layer thickness and scanning space, etc. has great influence on the thin wall's qualities. The aim of this work is to relate the thin wall's parameters (responses), namely track width, surface roughness and hardness to the process parameters considered in this research (laser power, scanning speed and layer thickness) and to find out the optimal manufacturing conditions. Design of experiment (DoE) was used by implementing composite central design to achieve better manufacturing qualities. Mathematical models derived from the statistical analysis were used to establish the relationships between the process parameters and the responses. Also, the effects of process parameters on each response were determined. Then, a numerical optimization was performed to find out the optimal process set at which the quality features are at their desired values. Based on this study, the relationship between process parameters and SLMed thin-walled structure was revealed and thus, the corresponding optimal process parameters can be used to manufactured thin-walled parts with high quality.

  4. Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical delta winglets

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, Michael J.; Thole, Karen A. [Mechanical and Nuclear Engineering Department, The Pennsylvania State University, University Park, PA 16802 (United States)

    2008-05-15

    Delta winglets are known to induce the formation of streamwise vortices and increase heat transfer between a working fluid and the surface on which the winglets are placed. This study investigates the use of delta winglets to augment heat transfer on the tube surface of louvered fin heat exchangers. It is shown that delta winglets placed on louvered fins produce augmentations in heat transfer along the tube wall as high as 47% with a corresponding increase of 19% in pressure losses. Manufacturing constraints are considered in this study whereby piercings in the louvered fins resulting from stamping the winglets into the louvered fins are simulated. Comparisons of measured heat transfer coefficients with and without piercings indicate that piercings reduce average heat transfer augmentations, but significant increases still occur with respect to no winglets present. (author)

  5. Highly transparent and conductive thin films fabricated with nano-silver/double-walled carbon nanotube composites.

    Science.gov (United States)

    Lee, Shie-Heng; Teng, Chih-Chun; Ma, Chen-Chi M; Wang, Ikai

    2011-12-01

    This study develops a technique for enhancing the electrical conductivity and optical transmittance of transparent double-walled carbon nanotube (DWNT) film. Silver nanoparticles were modified with a NH(2)(CH(2))(2)SH self-assembled monolayer terminated by amino groups and subsequent surface condensation that reacted with functionalized DWNTs. Ag nanoparticles were grafted on the surface of the DWNTs. The low sheet resistance of the resulting thin conductive film on a polyethylene terephthalate (PET) substrate was due to the increased contact areas between DWNTs and work function by grafting Ag nanoparticles on the DWNT surfaces. Increasing the contact area between DWNTs and work function improved the conductivity of the DWNT-Ag thin films. The prepared DWNT-Ag thin films had a sheet resistance of 53.4 Ω/sq with 90.5% optical transmittance at a 550 nm wavelength. After treatment with HNO(3) and annealing at 150 °C for 30 min, a lower sheet resistance of 45.8 Ω/sq and a higher transmittance of 90.4% could be attained. The value of the DC conductivity to optical conductivity (σ(DC)/σ(OP)) ratio is 121.3. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Switching process between bistable positons of multiquantum flux tubes in a thin-film type I superconductor

    International Nuclear Information System (INIS)

    Parisi, J.; Huebener, R.P.; Muhlemeier, B.

    1983-01-01

    A superconducting memory device based on a bistable vortex position represents an interesting storage medium for future Josephson computers. In order to study the operational mode of such a single-flux quantum memory cell, we use as a model system multiquantum flux tubes in a thin-film type I superconductor (Pb). By employing high-resolution stroboscopic magnetooptical flux detection, we are able to globally visualize both spatial and temporal behavior of rapidly switching individual flux tubes. All experimental results agree reasonably well with theoretical model considerations of the energy balance during the elementary switching process

  7. The effect of water jet lancing on furnace wall tubes of high slagged deposit fuel-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, V V; Kovalevitch, I A; Maidanik, M N [All-Union Heat Engineering Institute, Siberian Branch, Krasnoyarsk (USSR)

    1990-01-01

    In this paper the results of investigating the effectiveness of water jet lancing on furnace wall tubes of slagged deposits fuels fired boilers type E-500, P-64, P-67 are given. The boilers of these types are designed to burn Jugoslavian lignites are Beresovo lignites of the Kansk-Achinsk deposits. Recommendations for usage of low retractable, long retractable and long-range water blowers, depending on the design, produced in the USSR, the furnace dimension and stability of deposits are given as well.

  8. Dynamic behavior of radiant cooling system based on capillary tubes in walls made of high performance concrete

    DEFF Research Database (Denmark)

    Mikeska, Tomás; Svendsen, Svend

    2015-01-01

    elements made of high performance concrete. The influence of the radiant cooling system on the indoor climate of the test room in terms of the air, surface and operative temperatures and velocities was investigated.The results show that the temperature of the room air can be kept in a comfortable range...... using cooling water for the radiant cooling system with a temperature only about 4K lower than the temperature of the room air. The relatively high speed reaction of the designed system is a result of the slim construction of the sandwich wall elements made of high performance concrete. (C) 2015...... the small amount of fresh air required by standards to provide a healthy indoor environment.This paper reports on experimental analyses evaluating the dynamic behavior of a test room equipped with a radiant cooling system composed of plastic capillary tubes integrated into the inner layer of sandwich wall...

  9. A study on optimization of laser-generated ultrasound for evaluation of wall-thinning in pipelines

    International Nuclear Information System (INIS)

    Kang, Seung Hyun; Lee, Joon Hyun; Cho, Youn Ho

    2004-01-01

    Carbon steel pipes of nuclear power plants, local wall thinning may result from erosion-corrosion or FAC(Flow Accelerated Corrosion) damage. Local wall thinning is one of the major causes for the structural fracture of these pipes. Therefore, assessment of local wall thinning due to corrosion is an important issue in nondestructive evaluation for the integrity of nuclear power plants. In this study, a pulsed laser with an linear array slit generated guided waves in a carbon steel pipe. Time-frequency analysis of ultrasonic waveforms using the wavelet transform allowed the identification of generated guided wave modes by comparison with the theoretical dispersion curves. This study shows some experimental results about optimization of generating laser ultrasound using various linear array slits.

  10. Studies on Various Functional Properties of Titania Thin Film Developed on Glazed Ceramic Wall Tiles

    Science.gov (United States)

    Anil, Asha; Darshana R, Bangoria; Misra, S. N.

    A sol-gel based TiO2 thin film was applied on glazed wall tiles for studying its various functional properties. Thin film was deposited by spin coating on the substrate and subjected to curing at different temperatures such as 600°C, 650, 700°C, 750°C and 800°C with 10 minutes soaking. The gel powder was characterized by FTIR, DTA/TG and XRD. Microstructure of thin film was analyzed by FESEM and EDX. Surface properties of the coatings such as gloss, colour difference, stain resistance, mineral hardness and wettability were extensively studied. The antibacterial activity of the surface of coated substrate against E. coli was also examined. The durability of the coated substrate in comparison to the uncoated was tested against alkali in accordance with ISO: 10545 (Part 13):1995 standard. FESEM images showed that thin films are dense and homogeneous. Coated substrates after firing results in lustre with high gloss, which increased from 330 to 420 GU as the curing temperature increases compared to that of uncoated one (72 GU). Coated substrate cured at 800°C shows higher mineral hardness (5 Mohs’) compared to uncoated one (4 Mohs’) and films cured at all temperatures showed stain resistance. The experimental results showed that the resistance towards alkali attack increase with increase in curing temperature and alkali resistance of sample cured at 800 °C was found to be superior compared to uncoated substrate. Contact angle of water on coated surface of substrates decreased with increase in temperature. Bacterial reduction percentages of the coated surface was 97% for sample cured at 700°C and it decreased from 97% to 87% as the curing temperature increased to 800 °C when treated with E. coli bacteria.

  11. Study on flow instability for feasibility of a thin liquid film first wall

    Energy Technology Data Exchange (ETDEWEB)

    Okino, Fumito, E-mail: fumito.okino@iae.kyoto-u.ac.jp [Kyoto University Graduate School of Energy Science, Gokasho Uji, Kyoto (Japan); Kasada, Ryuta; Konishi, Satoshi [Kyoto University Institute of Advanced Energy, Gokasho Uji, Kyoto (Japan)

    2014-10-15

    Highlights: • We propose a probability of an instability wave growth on a liquid metal first wall. • Evaporated gas by the high energy flux is predicted to agitate this instability wave. • Liquid Pb-17Li with a velocity 10 m/s, the ambient gas must be below 6.2 × 10{sup 3} Pa. • This pressure corresponds to 1600 K and it is attainable under a fusion energy flux. • This probability is not yet verified so the full verifications are to be performed. - Abstract: This study proposes a probability of the evaporated gas that agitates a growing instability wave in a thin liquid film first wall. The liquid first wall was considered to be in vacuum and the effect of the ambient gas was neglected but the evaporated gas by the high energy fluxes is a probable cause of unstable wave agitation. The criterion is approximately expressed by the density ratio (Q{sub 2}) and the Weber number (We) as Q{sub 2} × We{sup 0.5} ≈ 5 × 10{sup −4}. Performed indirect experimental supported this criterion. For a case study of liquid Pb-17Li film with a velocity of 10 m/s, the evaporated gas pressure must be below 6.2 × 10{sup 3} Pa to maintain stable conditions. By recent study, this pressure is generated at 1600 K temperature and it is believed to be attainable by the energy fluxes on the first wall. This result is so far not confirmed so the full verification by experimental is to be performed.

  12. Theoretical Analysis of Effects of Wall Suction on Entropy Generation Rate in Laminar Condensate Layer on Horizontal Tube

    Directory of Open Access Journals (Sweden)

    Tong-Bou Chang

    2014-01-01

    Full Text Available The effects of wall suction on the entropy generation rate in a two-dimensional steady film condensation flow on a horizontal tube are investigated theoretically. In analyzing the liquid flow, the effects of both the gravitational force and the viscous force are taken into account. In addition, a film thickness reduction ratio, Sf, is introduced to evaluate the effect of wall suction on the thickness of the condensate layer. The analytical results show that, the entropy generation rate depends on the Jakob number Ja, the Rayleigh number Ra, the Brinkman number Br, the dimensionless temperature difference ψ, and the wall suction parameter Sw. In addition, it is shown that in the absence of wall suction, a closed-form correlation for the Nusselt number can be derived. Finally, it is shown that the dimensionless entropy generation due to heat transfer, NT, increases with an increasing suction parameter Sw, whereas the dimensionless entropy generation due to liquid film flow friction, NF, decreases.

  13. Behavior of thin-walled beams made of advanced composite materials and incorporating non-classical effects

    Science.gov (United States)

    Librescu, Liviu; Song, Ohseop

    1991-11-01

    Several results concerning the refined theory of thin-walled beams of arbitrary closed cross-section incorporating nonclassical effects are presented. These effects are related both with the exotic properties characterizing the advanced composite material structures and the nonuniform torsional model. A special case of the general equations is used to study several problems of cantilevered thin-walled beams and to assess the influence of the incorporated effects. The results presented in this paper could be useful toward a more rational design of aeronautical or aerospace constructions, as well as of helicopter or tilt rotor blades constructed of advanced composite materials.

  14. Economic Analysis of Installing Fixed and Removable Insulation for Pipe Wall Thinning Management

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kyeongmo; Yun, Hun [KEPCO E and C, Gimcheon (Korea, Republic of)

    2016-12-15

    To perform ultrasonic testing (UT) thickness measurement of the secondary side piping installed in nuclear power plants, the insulation for preventing heat loss should be removed. The type of insulation can be divided into fixed and removable insulation. Fixed and removable insulation have their own strengths and weaknesses. Removable insulation has been installed in the components susceptible to wall thinning caused by FAC and erosion from Shin-Kori unit 1, which commenced its commercial operation in 2011. In this paper, the number of repeated inspections of components and the number of replacements of fixed insulation were estimated and a more economical way was identified based on the manufacturing and installation costs for fixed and removable insulation.

  15. Degenerated shell element for geometrically nonlinear analysis of thin-walled piezoelectric active structures

    International Nuclear Information System (INIS)

    Marinković, D; Köppe, H; Gabbert, U

    2008-01-01

    Active piezoelectric thin-walled structures, especially those with a notably higher membrane than bending stiffness, are susceptible to large rotations and transverse deflections. Recent investigations conducted by a number of researchers have shown that the predicted behavior of piezoelectric structures can be significantly influenced by the assumption of large displacements and rotations of the structure, thus demanding a geometrically nonlinear formulation in order to investigate it. This paper offers a degenerated shell element and a simplified formulation that relies on small incremental steps for the geometrically nonlinear analysis of piezoelectric composite structures. A set of purely mechanical static cases is followed by a set of piezoelectric coupled static cases, both demonstrating the applicability of the proposed formulation

  16. Transparent and flexible electrodes and supercapacitors using polyaniline/single-walled carbon nanotube composite thin films

    Science.gov (United States)

    Ge, Jun; Cheng, Guanghui; Chen, Liwei

    2011-08-01

    Large-scale transparent and flexible electronic devices have been pursued for potential applications such as those in touch sensors and display technologies. These applications require that the power source of these devices must also comply with transparent and flexible features. Here we present transparent and flexible supercapacitors assembled from polyaniline (PANI)/single-walled carbon nanotube (SWNT) composite thin film electrodes. The ultrathin, optically homogeneous and transparent, electrically conducting films of the PANI/SWNT composite show a large specific capacitance due to combined double-layer capacitance and pseudo-capacitance mechanisms. A supercapacitor assembled using electrodes with a SWNT density of 10.0 µg cm-2 and 59 wt% PANI gives a specific capacitance of 55.0 F g-1 at a current density of 2.6 A g-1, showing its possibility for transparent and flexible energy storage.

  17. Effect of Eccentricity of Load on Critical Force of Thin-Walled Columns CFRP

    Directory of Open Access Journals (Sweden)

    Pawel Wysmulski

    2017-09-01

    Full Text Available The subject of study was a thin-walled C-section made of carbon fiber reinforced polymer (CFRP. Column was subjected to eccentric compression in the established direction. In the computer simulation, the boundary conditions were assumed in the form of articulated support of the sections of the column. Particular studies included an analysis of the effects of eccentricity on the critical force value. The research was conducted using two independent research methods: numerical and experimental. Numerical simulations were done using the finite element method using the advanced system Abaqus®. The high sensitivity of the critical force value corresponding to the local buckling of the channel section to the load eccentricity was demonstrated.

  18. Optimal Shakedown of the Thin-Wall Metal Structures Under Strength and Stiffness Constraints

    Directory of Open Access Journals (Sweden)

    Alawdin Piotr

    2017-06-01

    Full Text Available Classical optimization problems of metal structures confined mainly with 1st class cross-sections. But in practice it is common to use the cross-sections of higher classes. In this paper, a new mathematical model for described shakedown optimization problem for metal structures, which elements are designed from 1st to 4th class cross-sections, under variable quasi-static loads is presented. The features of limited plastic redistribution of forces in the structure with thin-walled elements there are taken into account. Authors assume the elastic-plastic flexural buckling in one plane without lateral torsional buckling behavior of members. Design formulae for Methods 1 and 2 for members are analyzed. Structures stiffness constrains are also incorporated in order to satisfy the limit serviceability state requirements. With the help of mathematical programming theory and extreme principles the structure optimization algorithm is developed and justified with the numerical experiment for the metal plane frames.

  19. Wall thinning inspection technique for large-diameter piping using guided wave

    International Nuclear Information System (INIS)

    Miki, Masahiro; Nagashima, Yoshiaki; Endou, Masao; Kodaira, Kojiro; Maniwa, Kazuhiko

    2009-01-01

    Guided wave inspection technique is effective for detecting defects like corrosion in piping, because it can perform long range inspection. It is possible to expect this inspection as a method that leads to the decrease of the inspection process and its cost, because the incidental work can be reduced. Especially, the contraction effect of the inspection work is extensive in large-diameter piping inspection. In this paper, we introduce the guided wave inspection system to large-diameter piping. The feature is a guided wave sensor that can freely transform according to the curvature of inspection object, and portable inspection equipment. We discuss the result of detection examination for artificial wall-thinning in large-diameter piping using this system. (author)

  20. Erosion corrosion in power plant piping systems - Calculation code for predicting wall thinning

    International Nuclear Information System (INIS)

    Kastner, W.; Erve, M.; Henzel, N.; Stellwag, B.

    1990-01-01

    Extensive experimental and theoretical investigations have been performed to develop a calculation code for wall thinning due to erosion corrosion in power plant piping systems. The so-called WATHEC code can be applied to single-phase water flow as well as to two-phase water/steam flow. Only input data which are available to the operator of the plant are taken into consideration. Together with a continuously updated erosion corrosion data base the calculation code forms one element of a weak point analysis for power plant piping systems which can be applied to minimize material loss due to erosion corrosion, reduce non-destructive testing and curtail monitoring programs for piping systems, recommend life-extending measures. (author). 12 refs, 17 figs

  1. Survey of a wireless NDT service for a nuclear piping wall thinning defect

    International Nuclear Information System (INIS)

    Choi, Yoo Rark; Lee, Jae Cheol

    2008-01-01

    The wireless sensor network has been issued for several years. The nuclear power plants all around world have adapted many kinds of sensor technologies for inspections and diagnostics of main instruments. Even though wireless sensor is more useful than wired sensor, wireless sensor based applications haven't been used in nuclear power plants because of the authorization of a jamming, an electromagnetic interference and so on. A wireless sensor uses a battery for its operations, but this battery can't be used for a long haul. It causes a battery change problem. There aren't any wireless sensor based NDT for a piping wall thinning part. We will describe a method of how to develop it in this paper

  2. Molecularly ordered aluminum tris-(8-hydroxyquinoline) thin films grown by hot-wall deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tapponnier, A. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland)]. E-mail: axelle@phys.ethz.ch; Khan, R.U.A. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland); Marcolli, C. [Institute of Atmospheric and Climate Sciences, Swiss Federal Institute of Technology Zuerich (ETH), CH-8092 Zurich (Switzerland); Guenter, P. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland)

    2007-01-22

    We report on the growth and microstructural analysis of molecularly ordered thin film layers of aluminum tris-(8-hydroxyquinoline) (Alq{sub 3}) by hot-wall deposition onto amorphous glass substrates. Using transmission electron microscopy (TEM), ordering on a scale of 100 nm was observed. Raman measurements of these films indicated that they corresponded to the {alpha}-polymorph of crystalline Alq{sub 3}, and photoluminescence measurements exhibited a single broad peak centered at 500 nm, which is also consistent with the {alpha}-form. As a comparison, we deposited films of Alq3 using organic molecular beam deposition (OMBD), which exhibited no molecular ordering from the TEM studies. For these films, strong point-to-point variations in the Raman spectrum, and the existence of a double peak in the photoluminescence at 500 and 522 nm were observed. These measurements indicate that the OMBD films possess a mixture of both {alpha} and amorphous phases.

  3. Transparent and flexible supercapacitors with single walled carbon nanotube thin film electrodes.

    Science.gov (United States)

    Yuksel, Recep; Sarioba, Zeynep; Cirpan, Ali; Hiralal, Pritesh; Unalan, Husnu Emrah

    2014-09-10

    We describe a simple process for the fabrication of transparent and flexible, solid-state supercapacitors. Symmetric electrodes made up of binder-free single walled carbon nanotube (SWCNT) thin films were deposited onto polydimethylsiloxane substrates by vacuum filtration followed by a stamping method, and solid-state supercapacitor devices were assembled using a gel electrolyte. An optical transmittance of 82% was found for 0.02 mg of SWCNTs, and a specific capacitance of 22.2 F/g was obtained. The power density can reach to 41.5 kW · kg(-1) and shows good capacity retention (94%) upon cycling over 500 times. Fabricated supercapacitors will be relevant for the realization of transparent and flexible devices with energy storage capabilities, displays and touch screens in particular.

  4. Thermal modeling and analysis of thin-walled structures in micro milling

    Science.gov (United States)

    Zhang, J. F.; Ma, Y. H.; Feng, C.; Tang, W.; Wang, S.

    2017-11-01

    The numerical analytical model has been developed to predict the thermal effect with respect to thin walled structures by micro-milling. In order to investigate the temperature distribution around micro-edge of cutter, it is necessary to considering the friction power, the shearing power, the shear area between the tool micro-edge and materials. Due to the micro-cutting area is more difficult to be measured accurately, the minimum chip thickness as one of critical factors is also introduced. Finite element-based simulation was employed by the Advantedge, which was determined from the machining of Ti-6Al-4V over a range of the uncut chip thicknesses. Results from the proposed model have been successfully accounted for the effects of thermal softening for material.

  5. Structural performance of new thin-walled concrete sandwich panel system reinforced with bfrp shear connectors

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hulin, Thomas; Schmidt, Jacob Wittrup

    2013-01-01

    This paper presents a new thin-walled concrete sandwich panel system reinforced with basalt fiber-reinforced plastic (BFRP) with optimum structural performances and a high thermal resistance developed by Connovate and Technical University of Denmark. The shear connecting system made of a BFRP grid...... is described and provides information on the structural design with its advantages. Experimental and numerical investigations of the BFRP connecting systems were performed. The experimental program included testing of small scale specimens by applying shear (push-off) loading and semi-full scale specimens...... on finite element modelling showed that the developed panel system meets the objectives of the research and is expected to have promising future....

  6. A Variable Stiffness Analysis Model for Large Complex Thin-Walled Guide Rail

    Directory of Open Access Journals (Sweden)

    Wang Xiaolong

    2016-01-01

    Full Text Available Large complex thin-walled guide rail has complicated structure and no uniform low rigidity. The traditional cutting simulations are time consuming due to huge computation especially in large workpiece. To solve these problems, a more efficient variable stiffness analysis model has been propose, which can obtain quantitative stiffness value of the machining surface. Applying simulate cutting force in sampling points using finite element analysis software ABAQUS, the single direction variable stiffness rule can be obtained. The variable stiffness matrix has been propose by analyzing multi-directions coupling variable stiffness rule. Combining with the three direction cutting force value, the reasonability of existing processing parameters can be verified and the optimized cutting parameters can be designed.

  7. THIN-WALLED CROSS SECTION SHAPE INFLUENCE ON STEEL MEMBER RESISTANCE

    Directory of Open Access Journals (Sweden)

    Elżbieta Urbańska-Galewska

    2016-03-01

    Full Text Available This work describes why trending thin-walled technology is achieving popularity in steel construction sector. A purpose of this article is to present the influence of the cold-formed element cross-section shape on an axial compression and a bending moment resistance. The authors have considered four different shapes assuming constant section area and thickness. Calculations were based on three different steel grades taking into account local, distortional and overall buckling. The results are presented in a tabular and a graphical way and clearly confirm that cross-section forming distinctly impact the cold-formed member resistance. The authors choose these cross-sections that work better in compression state and the other (those slender and high that function more efficiently are subjected to bending.

  8. Application of numerical analysis technique to make up for pipe wall thinning prediction program

    International Nuclear Information System (INIS)

    Hwang, Kyeong Mo; Jin, Tae Eun; Park, Won; Oh, Dong Hoon

    2009-01-01

    Flow Accelerated Corrosion (FAC) leads to wall thinning of steel piping exposed to flowing water or wet steam. Experience has shown that FAC damage to piping at fossil and nuclear plants can lead to costly outages and repairs and can affect plant reliability and safety. CHEWORKS have been utilized in domestic nuclear plants as a predictive tool to assist FAC engineers in planning inspections and evaluating the inspection data to prevent piping failures caused by FAC. However, CHECWORKS may be occasionally left out local susceptible portions owing to predicting FAC damage by pipeline group after constructing a database for all secondary side piping in nuclear plants. This paper describes the methodologies that can complement CHECWORKS and the verifications of the CHECWORKS prediction results in terms of numerical analysis. FAC susceptible locations based on CHECWORKS for the two pipeline groups of a nuclear plant was compared with those of numerical analysis based on FLUENT.

  9. Upper and Lower Bound Limit Loads for Thin-Walled Pressure Vessels Used for Aerosol Cans

    Directory of Open Access Journals (Sweden)

    Stephen John Hardy

    2009-01-01

    Full Text Available The elastic compensation method proposed by Mackenzie and Boyle is used to estimate the upper and lower bound limit (collapse loads for one-piece aluminium aerosol cans, which are thin-walled pressure vessels subjected to internal pressure loading. Elastic-plastic finite element predictions for yield and collapse pressures are found using axisymmetric models. However, it is shown that predictions for the elastic-plastic buckling of the vessel base require the use of a full three-dimensional model with a small unsymmetrical imperfection introduced. The finite element predictions for the internal pressure to cause complete failure via collapse fall within the upper and lower bounds. Hence the method, which involves only elastic analyses, can be used in place of complex elastic-plastic finite element analyses when upper and lower bound estimates are adequate for design purposes. Similarly, the lower bound value underpredicts the pressure at which first yield occurs.

  10. The Versatile Elastohydrodynamics of a Free Particle near a Thin Soft Wall

    Science.gov (United States)

    Salez, Thomas; Saintyves, Baudouin; Mahadevan, L.

    2015-03-01

    We address the free motion of a buoyant particle inside a viscous fluid, in the vicinity of a thin compressible elastic wall. After discussing the main scalings, we obtain analytically the dominant drag forces within the soft lubrication approximation. By including those into the equations of motion of the particle, we establish a general governing system of three coupled nonlinear and singular differential equations, that describe the three essential motions: sedimentation, hydroplaning, and hydrospinning, through four dimensionless control parameters. Numerical integration allows us to predict a wide zoology of exotic solutions - despite the low-Reynolds feature of the flow - including: spontaneous oscillation, Magnus-like effect, enhanced sedimentation, and boomerang-like effect. We compare these predictions to experiments. The presented elementary approach could be of interest in the description of a broad variety of elastohydrodynamical phenomena, including: landslides, ageing of cartilaginous joints, and motion of a cell in a microfluidic channel or in a blood vessel.

  11. Effect of load eccentricity on the buckling of thin-walled laminated C-columns

    Science.gov (United States)

    Wysmulski, Pawel; Teter, Andrzej; Debski, Hubert

    2018-01-01

    The study investigates the behaviour of short, thin-walled laminated C-columns under eccentric compression. The tested columns are simple-supported. The effect of load inaccuracy on the critical and post-critical (local buckling) states is examined. A numerical analysis by the finite element method and experimental tests on a test stand are performed. The samples were produced from a carbon-epoxy prepreg by the autoclave technique. The experimental tests rest on the assumption that compressive loads are 1.5 higher than the theoretical critical force. Numerical modelling is performed using the commercial software package ABAQUS®. The critical load is determined by solving an eigen problem using the Subspace algorithm. The experimental critical loads are determined based on post-buckling paths. The numerical and experimental results show high agreement, thus demonstrating a significant effect of load inaccuracy on the critical load corresponding to the column's local buckling.

  12. Optimization process for thin-walled high performance concrete sandwich panels

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hulin, Thomas; Schmidt, Jacob Wittrup

    2014-01-01

    with the specifications of the design constrains and variables. The tool integrates the processes of HPCSP design, quantity take-off and cost estimation into a single system that would provide different costs for different HPCSP designs. The proposed multi-objective optimisation scheme results into derivation of basic......A Nearly zero energy buildings are to become a requirement as part of the European energy policy. There are many ways of designing nearly zero energy buildings, but there is a lack of knowledge on optimization processes in the sense of structurally and thermally efficient design with an optimal...... economical solution. The present paper aims to provide multi-objective optimisation procedure addressed to structural precast thin-walled High Performance Concrete Sandwich Panels (HPCSP). The research aim is concerned with developing a tool that considers the cost of HPCSP materials along...

  13. Parametric analysis of AAR influent factors on thin-walled columns

    Directory of Open Access Journals (Sweden)

    E. L. Madureira

    Full Text Available ABSTRACTThe chemical reaction involving the alkalis of the cement and some minerals of the concrete aggregates, the Alkali-Aggregate Reaction or, simply, the AAR, promotes swelling and material damages. Despite the development stage of the researches on this pathology effects, its solution modeling still lacks refinement. The numerical simulation is an important resource for the structural damages evaluation due to AAR, and their repairs. The aim of this work is the numerical simulation of concrete thin-walled columns, affected by the AAR, from the finite element approximation on an orthotropic nonlinear framework, and a thermodynamic model designed to the assessment of the AAR swelling, with highlight on the compressive stress, the reinforcement and the temperature influences on the phenomenon. The obtained results revealed that the AAR induced the concrete strength decrease and the consequent reduction in preventive safety margin to the material failure, being more precocious at higher temperatures.

  14. Cost optimization of load carrying thin-walled precast high performance concrete sandwich panels

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hansen, Sanne; Hulin, Thomas

    2015-01-01

    and HPCSP’s geometrical parameters as well as on material cost function in the HPCSP design. Cost functions are presented for High Performance Concrete (HPC), insulation layer, reinforcement and include labour-related costs. The present study reports the economic data corresponding to specific manufacturing......The paper describes a procedure to find the structurally and thermally efficient design of load-carrying thin-walled precast High Performance Concrete Sandwich Panels (HPCSP) with an optimal economical solution. A systematic optimization approach is based on the selection of material’s performances....... The solution of the optimization problem is performed in the computer package software Matlab® with SQPlab package and integrates the processes of HPCSP design, quantity take-off and cost estimation. The proposed optimization process outcomes in complex HPCSP design proposals to achieve minimum cost of HPCSP....

  15. Evaluation of endcap welds in thin walled fuel elements of pressurised heavy water reactor by ultrasonic testing

    International Nuclear Information System (INIS)

    Subramanian, C.V.; Thavasimuthu, M.; Kalyansundaram, P.; Bhattacharya, D.K.; Raj, Baldev

    1992-01-01

    In the pressurised heavy water reactor systems of India, the fuel is encapsulated in thin-walled tubes (0.342 mm) closed with endcaps by resistance welding. The integrity of these fuel elements should be such that no fission gas leakage takes place during reactor operation. The quality control of the endcap welds needed to satisfy this requirement includes helium leak test and destructive metallographic test (on sample basis). This paper discusses the feasibility study that has been carried out in the author's laboratory to develop an immersion ultrasonic test method for evaluating the integrity of the endcap weld region. Through holes of various sizes (0.15mm, 0.2mm, 0.4mm diameter and 0.185mm and 0.342mm deep) were machined by spark erosion machining at the weld joints to simulate defects of various sizes. Line focussed probe of 10 MHz frequency was used for the testing. It was possible to detect clearly all the machined holes. Based on the above standardised procedure, further testing was done on endcap welds which were rejected during fabrication on account of showing leak rate of 3 x 10 -6 std. c.c/sec. or more during helium leak test. Though it was possible to get echoes from the natural defects in the rejected tubes with echo amplitude of 70%, the signal was accompanied by the geometrical reflection (noise) giving an amplitude of 20% from the weld region, giving rise to the problem of resolving the defect indication from the geometric indications. Therefore, signal analysis approach was adopted. The signal obtained from the weld zone were subjected to various analysis procedures like a) autopower spectrum, b) total energy content and c) demodulated auto correlation function. It was possible by all the three methods to differentiate the defect signal from those due to weld geometry or due to noise. Subsequently, metallography was carried out to characterise the type of defects observed during the ultrasonic testing. (author). 4 figs

  16. Rational use of anchor pile material of the thin retaining walls

    Directory of Open Access Journals (Sweden)

    Yushkov Boris Semenovich

    2014-12-01

    Full Text Available The article considers the urgency of application of the reinforced concrete anchor piles in the constructions of retaining structures associated with the possibility of establishing rigid joint of element interface and more durable pile constructions in the soil. The features of the inclined anchor piles work as a part of sheet-pile retaining walls are noted. There was performed a study of the stress-strain state of the inclined reinforced concrete anchor piles of the thin sheet-pile wall with the reinforced concrete face members of T-section, combined with piles by a longitudinal beam. The authors consider a constructive scheme of retaining structure and list the applied loads. The efforts in the anchor piles were determined. The bending-moment curves show the character of the force distribution along the pile. A form of the pile ensuring the rational distribution of material along the pile is presented. The distribution of efforts along the length and effect of filling on its operation in the soil were accepted as the criteria of construction solution for a pile. The substantiation of the proposed design of pile is presented in terms of its stress-strain state and the rational use of material. The authors made conclusions on the reasonability of adopted design solutions associated with an increase in the flexural strength of pile, increment of the ultimate pullout capacity, stability improvement, effective use of backfill and exception of the «out of operation» areas of the pile.

  17. PRODUCTION OF URANIUM TUBING

    Science.gov (United States)

    Creutz, E.C.

    1958-04-15

    The manufacture of thin-walled uranium tubing by the hot-piercing techique is described. Uranium billets are preheated to a temperature above 780 d C. The heated billet is fed to a station where it is engaged on its external surface by three convex-surfaced rotating rollers which are set at an angle to the axis of the billet to produce a surface friction force in one direction to force the billet over a piercing mandrel. While being formed around the mandrel and before losing the desired shape, the tube thus formed is cooled by a water spray.

  18. Single-Walled Carbon Nano tubes as Fluorescence Biosensors for Pathogen Recognition in Water Systems

    International Nuclear Information System (INIS)

    Upadhyayula, V.K.K

    2008-01-01

    The possibility of using single-walled carbon nanotubes (SWCNTs) aggregates as fluorescence sensors for pathogen recognition in drinking water treatment applications has been studied. Batch adsorption study is conducted to adsorb large concentrations of Staphylococcus aureus aureus SH 1000 and Escherichia coli pKV-11 on single-walled carbon nanotubes. Subsequently the immobilized bacteria are detected with confocal microscopy by coating the nanotubes with fluorescence emitting antibodies. The Freundlich adsorption equilibrium constant (k) for S.aureus and E.coli determined from batch adsorption study was found to be 9 x108 and 2 x108 ml/g, respectively. The visualization of bacterial cells adsorbed on fluorescently modified carbon nanotubes is also clearly seen. The results indicate that hydrophobic single-walled carbon nanotubes have excellent bacterial adsorption capacity and fluorescent detection capability. This is an important advancement in designing fluorescence biosensors for pathogen recognition in water systems.

  19. Multiple, thin-walled cysts are one of the HRCT features of airspace enlargement with fibrosis

    International Nuclear Information System (INIS)

    Watanabe, Yasutaka; Kawabata, Yoshinori; Kanauchi, Tetsu; Hoshi, Eishin; Kurashima, Kazuyoshi; Koyama, Shinichiro; Colby, Thomas V.

    2015-01-01

    Highlights: • High resolution computed tomography (HRCT) findings of airspace enlargement with fibrosis (AEF), recently identified as a smoking related change. • Investigation was in 35 smokers. • They underwent lobectomy for lung cancer with pathological confirmation of AEF. • Multiple, thin-walled cysts are one of the HRCT features of AEF. - Abstract: Purpose: Airspace enlargement with fibrosis (AEF) has been identified pathologically as a smoking related change. We sought to identify the HRCT findings of AEF and search for distinguishing features from honeycombing. Materials and methods: 50 patients (47 males; mean age 69) were evaluated. All had undergone lobectomy for lung cancer and had confirmed AEF and/or usual interstitial pneumonia (UIP) by pathological evaluation. HRCT findings were first evaluated preresection for resected lobes, and then correlated with the subsequent pathological findings in the resection specimens. Three groups were devised: one with AEF alone to determine the HRCT findings of AEF, a second with AEF and UIP and third with UIP alone. HRCT features of AEF and honeycombing were compared. Results: There were 11 patients (10 male; mean age 69) with AEF alone, 24 patients (22 male; mean age 69) with AEF and UIP, and 15 patients (15 male; mean age 68) with UIP alone. The HRCT on the AEF alone showed subpleural (but not abutting the pleura) multiple thin-walled cysts (MTWCs) in 7 and reticular opacities in 3. The HRCT in AEF and UIP showed MTWCs in 10, reticular opacities in 17; and honeycombing in 5. Among these 35 patients with the pathological finding of AEF (with or without UIP), 17 showed MTWCs. The maximum cyst wall thickness of MTWCs (mean 0.81 mm) was significantly thinner than that of honeycombing (mean 1.56 mm). MTWCs did not locate in lung base and was distant from the pleura. HRCT findings correlated with gross findings on both cysts and honeycombing. No MTWCs were seen in the 15 patients with UIP, 8 of 15 had

  20. Long-Term Bending Creep Behavior of Thin-Walled CFRP Tendon Pretensioned Spun Concrete Poles

    Directory of Open Access Journals (Sweden)

    Giovanni P. Terrasi

    2014-07-01

    Full Text Available This paper discusses the long-term behavior of a series of highly-loaded, spun concrete pole specimens prestressed with carbon fiber-reinforced polymer (CFRP tendons, which were subjected to outdoor four-point bending creep tests since 1996 in the frame of collaboration with the Swiss precast concrete producer, SACAC (Società Anonima Cementi Armati Centrifugati. The 2 m span cylindrical beams studied are models for lighting poles produced for the last 10 years and sold on the European market. Five thin-walled pole specimens were investigated (diameter: 100 mm; wall-thickness: 25–27 mm. All specimens were produced in a pretensioning and spinning technique and were prestressed by pultruded CFRP tendons. Initially, two reference pole specimens were tested in quasi-static four-point bending to determine the short-term failure moment and to model the short-term flexural behavior. Then, three pole specimens were loaded to different bending creep moments: while the lowest loaded specimen was initially uncracked, the second specimen was loaded with 50% of the short-term bending failure moment and exhibited cracking immediately after load introduction. The highest loaded pole specimen sustained a bending moment of 72% of the short-term bending failure moment for 16.5 years before failing in July 2013, due to the bond failure of the tendons, which led to local crushing of the high-performance spun concrete (HPSC. Besides this, long-term monitoring of the creep tests has shown a limited time- and temperature-dependent increase of the deflections over the years, mainly due to the creep of the concrete. A concrete creep-based model allowed for the calculation of the long-term bending curvatures with reasonable accuracy. Furthermore, the pole specimens showed crack patterns that were stable over time and minimal slippage of the tendons with respect to the pole’s end-faces for the two lower load levels. The latter proves the successful and durable

  1. Multiple, thin-walled cysts are one of the HRCT features of airspace enlargement with fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yasutaka, E-mail: yasuyasu@omiya.jichi.ac.jp [Division of Diagnostic Pathology, Saitama Prefectural Cardiovascular and Respiratory Center, 1696 Itai, Kumagaya City, Saitama 360-0105 (Japan); Division of Pulmonary Medicine, Clinical Department of Internal Medicine, Jichi Medical University, Saitama Medical Center, Amanuma-cho, Omiya City, Saitama 330-8503 (Japan); Kawabata, Yoshinori [Division of Diagnostic Pathology, Saitama Prefectural Cardiovascular and Respiratory Center, 1696 Itai, Kumagaya City, Saitama 360-0105 (Japan); Kanauchi, Tetsu [Department of Radiology, Saitama Prefectural Cardiovascular and Respiratory Center, 1696 Itai, Kumagaya City, Saitama 360-0105 (Japan); Hoshi, Eishin [Department of Thoracic Surgery, Saitama Prefectural Cardiovascular and Respiratory Center, 1696 Itai, Kumagaya City, Saitama 360-0105 (Japan); Kurashima, Kazuyoshi [Department of Pulmonary Medicine, Saitama Prefectural Cardiovascular and Respiratory Center, 1696 Itai, Kumagaya City, Saitama 360-0105 (Japan); Koyama, Shinichiro [Division of Pulmonary Medicine, Clinical Department of Internal Medicine, Jichi Medical University, Saitama Medical Center, Amanuma-cho, Omiya City, Saitama 330-8503 (Japan); Colby, Thomas V. [Department of Laboratory Medicine and Pathology, Mayo Clinic Scottsdale, Scottsdale, AZ 85259 (United States)

    2015-05-15

    Highlights: • High resolution computed tomography (HRCT) findings of airspace enlargement with fibrosis (AEF), recently identified as a smoking related change. • Investigation was in 35 smokers. • They underwent lobectomy for lung cancer with pathological confirmation of AEF. • Multiple, thin-walled cysts are one of the HRCT features of AEF. - Abstract: Purpose: Airspace enlargement with fibrosis (AEF) has been identified pathologically as a smoking related change. We sought to identify the HRCT findings of AEF and search for distinguishing features from honeycombing. Materials and methods: 50 patients (47 males; mean age 69) were evaluated. All had undergone lobectomy for lung cancer and had confirmed AEF and/or usual interstitial pneumonia (UIP) by pathological evaluation. HRCT findings were first evaluated preresection for resected lobes, and then correlated with the subsequent pathological findings in the resection specimens. Three groups were devised: one with AEF alone to determine the HRCT findings of AEF, a second with AEF and UIP and third with UIP alone. HRCT features of AEF and honeycombing were compared. Results: There were 11 patients (10 male; mean age 69) with AEF alone, 24 patients (22 male; mean age 69) with AEF and UIP, and 15 patients (15 male; mean age 68) with UIP alone. The HRCT on the AEF alone showed subpleural (but not abutting the pleura) multiple thin-walled cysts (MTWCs) in 7 and reticular opacities in 3. The HRCT in AEF and UIP showed MTWCs in 10, reticular opacities in 17; and honeycombing in 5. Among these 35 patients with the pathological finding of AEF (with or without UIP), 17 showed MTWCs. The maximum cyst wall thickness of MTWCs (mean 0.81 mm) was significantly thinner than that of honeycombing (mean 1.56 mm). MTWCs did not locate in lung base and was distant from the pleura. HRCT findings correlated with gross findings on both cysts and honeycombing. No MTWCs were seen in the 15 patients with UIP, 8 of 15 had

  2. Development of Wall-Thinning Evaluation Procedure for Nuclear Power Plant Piping—Part 1: Quantification of Thickness Measurement Deviation

    Directory of Open Access Journals (Sweden)

    Hun Yun

    2016-06-01

    Full Text Available Pipe wall thinning by flow-accelerated corrosion and various types of erosion is a significant and costly damage phenomenon in secondary piping systems of nuclear power plants (NPPs. Most NPPs have management programs to ensure pipe integrity due to wall thinning that includes periodic measurements for pipe wall thicknesses using nondestructive evaluation techniques. Numerous measurements using ultrasonic tests (UTs; one of the nondestructive evaluation technologies have been performed during scheduled outages in NPPs. Using the thickness measurement data, wall thinning rates of each component are determined conservatively according to several evaluation methods developed by the United States Electric Power Research Institute. However, little is known about the conservativeness or reliability of the evaluation methods because of a lack of understanding of the measurement error. In this study, quantitative models for UT thickness measurement deviations of nuclear pipes and fittings were developed as the first step for establishing an optimized thinning evaluation procedure considering measurement error. In order to understand the characteristics of UT thickness measurement errors of nuclear pipes and fittings, round robin test results, which were obtained by previous researchers under laboratory conditions, were analyzed. Then, based on a large dataset of actual plant data from four NPPs, a quantitative model for UT thickness measurement deviation is proposed for plant conditions.

  3. Thermodynamic optimization of a coiled tube heat exchanger under constant wall heat flux condition

    International Nuclear Information System (INIS)

    Satapathy, Ashok K.

    2009-01-01

    In this paper the second law analysis of thermodynamic irreversibilities in a coiled tube heat exchanger has been carried out for both laminar and turbulent flow conditions. The expression for the scaled non-dimensional entropy generation rate for such a system is derived in terms of four dimensionless parameters: Prandtl number, heat exchanger duty parameter, Dean number and coil to tube diameter ratio. It has been observed that for a particular value of Prandtl number, Dean number and duty parameter, there exists an optimum diameter ratio where the entropy generation rate is minimum. It is also found that with increase in Dean number or Reynolds number, the optimum value of the diameter ratio decreases for a particular value of Prandtl number and heat exchanger duty parameter.

  4. Sucrose Synthase Is Associated with the Cell Wall of Tobacco Pollen Tubes

    NARCIS (Netherlands)

    Persia, D.; Cai, G.; Casino, C.; Willemse, M.T.M.; Cresti, M.

    2008-01-01

    Sucrose synthase (Sus; EC 2.4.1.13) is a key enzyme of sucrose metabolism in plant cells, providing carbon for respiration and for the synthesis of cell wall polymers and starch. Since Sus is important for plant cell growth, insights into its structure, localization, and features are useful for

  5. SPONTANEOUS FALLOPIAN TUBE EVISCERATION IN PROCIDENTIA AND PERFORATING CARCINOMATOUS VAGINAL WALL ULCER – CASE REPORT

    Directory of Open Access Journals (Sweden)

    Marijan Lužnik

    2018-02-01

    Full Text Available Background. Total prolapse of female pelvic organs is not only painful and troublesome because of difficulties with micturition and defecation but it could be very dangerous since prolapsed vagina presents a predilection area for ulcer and/or rupture of different etiology and with evisceration of abdominal content. Eviscerations usually occur rarely, but when they do occur, it is important to intervene quickly. Most frequent is the evisceration of small bowel, rarely omentum and sporadically other abdominal structures. Neither in literature nor on the internet there were not any examples of primary eviscerated fallopian tube which was not a consequence of preceeding gynecological-surgical procedure found. Methods. 77-year-old woman was appointed to our out patient department with diagnosis of Prolapsus uteri totalis and Dolores abdominalis. In history there was prevulvar bulge in the size of an apple, which persisted for 20 years, and almost disappeared when lying supine. Three days before admission to the hospital the bulge was exceedingly enlarged by straining and did not diminish when lying supine. The patient walked only hardly and could not sit. Micturition and defecation was possible only in the upright position. There were also difficulties while placing the patient on a gynecologic chair, because between her legs there was a bulge in the size of 14 × 10 × 9 cm3 with fallopian tube hanging out (Figure 1. On the outermost part of total uterovaginal prolapse the outer ostium of the cervical canal was recognizable. The bulge was fully stretched, painful and unreponible. Around a hole where a fallopian tube exits, vagina was eritematous, rough folded – swollen and vulnerable (Figure 2. In outpatient department eviscerated fallopian tube and prolapsed vagina with its contents were aseptically treated and Dalacin and Orho Gynest crème were applicated. Foley catheter was inserted. Prolapsed vagina with uterus and other contents remained

  6. Characterization of mechanical properties of hydroxyapatite-silicon-multi walled carbon nano tubes composite coatings synthesized by EPD on NiTi alloys for biomedical application.

    Science.gov (United States)

    Khalili, Vida; Khalil-Allafi, Jafar; Sengstock, Christina; Motemani, Yahya; Paulsen, Alexander; Frenzel, Jan; Eggeler, Gunther; Köller, Manfred

    2016-06-01

    Release of Ni(1+) ions from NiTi alloy into tissue environment, biological response on the surface of NiTi and the allergic reaction of atopic people towards Ni are challengeable issues for biomedical application. In this study, composite coatings of hydroxyapatite-silicon multi walled carbon nano-tubes with 20wt% Silicon and 1wt% multi walled carbon nano-tubes of HA were deposited on a NiTi substrate using electrophoretic methods. The SEM images of coated samples exhibit a continuous and compact morphology for hydroxyapatite-silicon and hydroxyapatite-silicon-multi walled carbon nano-tubes coatings. Nano-indentation analysis on different locations of coatings represents the highest elastic modulus (45.8GPa) for HA-Si-MWCNTs which is between the elastic modulus of NiTi substrate (66.5GPa) and bone tissue (≈30GPa). This results in decrease of stress gradient on coating-substrate-bone interfaces during performance. The results of nano-scratch analysis show the highest critical distance of delamination (2.5mm) and normal load before failure (837mN) as well as highest critical contact pressure for hydroxyapatite-silicon-multi walled carbon nano-tubes coating. The cell culture results show that human mesenchymal stem cells are able to adhere and proliferate on the pure hydroxyapatite and composite coatings. The presence of both silicon and multi walled carbon nano-tubes (CS3) in the hydroxyapatite coating induce more adherence of viable human mesenchymal stem cells in contrast to the HA coated samples with only silicon (CS2). These results make hydroxyapatite-silicon-multi walled carbon nano-tubes a promising composite coating for future bone implant application. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. New technical knowledge to be implemented to the revision of rules on pipe wall thinning management for PWR Plants. 2006 edition

    International Nuclear Information System (INIS)

    Hirai, Junya; Amano, Yoichi; Nakamura, Takao

    2013-01-01

    Rules for PWR plant pipe wall thinning management were formulated by the Japan Society of Mechanical Engineers in 2006. Since then thinning management of Japanese PWR plants has been carried out based on this rule. Pipe wall thinning phenomena to be dealt with in this rule have been identified in many piping components of power plants. New technical knowledge has been accumulated since the issuance of 2006 edition. We have formulated these knowledge and information about the thinning phenomena in PWR power plants. Given the history of application of this rule, we have to make our best effort to carry out a study of latest technical knowledge and implement them to the revision of rule and improve pipe wall thinning management. This paper summarizes the new technical knowledge and basis to be implemented to the revision of rules on pipe wall thinning management for PWR plants in Japan. (author)

  8. Microstructure, elastic deformation behavior and mechanical properties of biomedical β-type titanium alloy thin-tube used for stents.

    Science.gov (United States)

    Tian, Yuxing; Yu, Zhentao; Ong, Chun Yee Aaron; Kent, Damon; Wang, Gui

    2015-05-01

    Cold-deformability and mechanical compatibility of the biomedical β-type titanium alloy are the foremost considerations for their application in stents, because the lower ductility restricts the cold-forming of thin-tube and unsatisfactory mechanical performance causes a failed tissue repair. In this paper, β-type titanium alloy (Ti-25Nb-3Zr-3Mo-2Sn, wt%) thin-tube fabricated by routine cold rolling is reported for the first time, and its elastic behavior and mechanical properties are discussed for the various microstructures. The as cold-rolled tube exhibits nonlinear elastic behavior with large recoverable strain of 2.3%. After annealing and aging, a nonlinear elasticity, considered as the intermediate stage between "double yielding" and normal linear elasticity, is attributable to a moderate precipitation of α phase. Quantitive relationships are established between volume fraction of α phase (Vα) and elastic modulus, strength as well as maximal recoverable strain (εmax-R), where the εmax-R of above 2.0% corresponds to the Vα range of 3-10%. It is considered that the "mechanical" stabilization of the (α+β) microstructure is a possible elastic mechanism for explaining the nonlinear elastic behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Standard guide for mutual inductance bridge applications for wall thickness determinations in boiler tubing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide describes a procedure for obtaining relative wall thickness indications in ferromagnetic and non-ferromagnetic steels using the mutual inductance bridge method. The procedure is intended for use with instruments capable of inducing two substantially identical magnetic fields and noting the change in inductance resulting from differing amounts of steel. It is used to distinguish acceptable wall thickness conditions from those which could place tubular vessels or piping at risk of bursting under high temperature and pressure conditions. 1.2 This guide is intended to satisfy two general needs for users of industrial Mutual Inductance Bridge (MIB) equipment: (1) the need for a tutorial guide addressing the general principles of Mutual Inductance Bridges as they apply to industrial piping; and (2) the need for a consistent set of MIB performance parameter definitions, including how these performance parameters relate to MIB system specifications. Potential users and buyers, as well as experienced M...

  10. The Effect of DNA and Sodium Cholate Dispersed Single-Walled Carbon Nano tubes on the Green Algae Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    Williams, R.M.; Cox, Z.; Dolash, B.D.; Sooter, L.J.; Williams, R.M.; Taylor, H.K.; Thomas, J.

    2014-01-01

    Increasing use of single-walled carbon nano tubes (SWCNTs) will lead to their increased release into the environment. Previous work has shown negative effects of SWCNT on growth and survival of model organisms. The aim of the current study was to determine the effect of SWCNT well-dispersed by either DNA or sodium cholate (SC) on the unicellular green algae Chlamydomonas reinhardtii in stagnant water conditions. Growth measurements were taken up to ten days for algae treated with varied levels of DNA:SWCNT or SC:SWCNT or controls, and chlorophyll content after 10 days was determined. Results show no effect on either growth or chlorophyll content of algae at any concentration or duration. This is in contradiction to prior work showing toxicity of SWCNT to environmental model organisms.

  11. Development and validation of an elastic and inelastic calculation method for tubes, based on beam models and taking into account the thermal stresses on the wall

    International Nuclear Information System (INIS)

    Krakowiak, C.

    1989-11-01

    A simplified model for the elastic-plastic calculations of thin and flexible tubes submitted to thermal stresses is presented. The method is based on beam models and provides satisfactory results concerning the displacement of the whole tube system. These results can be justified by the fact that the modifications of the tube cross sections (from circular to elliptical), the flexibility of the elbow joints and the radial temperature profile are included in the calculations. The thermoplasticity analysis is performed by defining independent and general flow directions and determining the corresponding behavior laws. The model is limited to proportional monotonous charging, however the obtained results are promissing [fr

  12. Mathematical Model of Stress-Strain State of Curved Tube of Non-Circular Cross-Section with Account of Technological Wall Thickness Variation

    Science.gov (United States)

    Pirogov, S. P.; Ustinov, N. N.; Smolin, N. I.

    2018-05-01

    A mathematical model of the stress-strain state of a curved tube of a non-circular cross-section is presented, taking into account the technological wall thickness variation. On the basis of the semi-membrane shell theory, a system of linear differential equations describing the deformation of a tube under the effect of pressure is obtained. To solve the boundary value problem, the method of shooting is applied. The adequacy of the proposed mathematical model is verified by comparison with the experimental data and the results of the calculation of tubes by the energy method.

  13. Methods and results for stress analyses on 14-ton, thin-wall depleted UF6 cylinders

    International Nuclear Information System (INIS)

    Kirkpatrick, J.R.; Chung, C.K.; Frazier, J.L.; Kelley, D.K.

    1996-10-01

    Uranium enrichment operations at the three US gaseous diffusion plants produce depleted uranium hexafluoride (DUF 6 ) as a residential product. At the present time, the inventory of DUF 6 in this country is more than half a million tons. The inventory of DUF 6 is contained in metal storage cylinders, most of which are located at the gaseous diffusion plants. The principal objective of the project is to ensure the integrity of the cylinders to prevent causing an environmental hazard by releasing the contents of the cylinders into the atmosphere. Another objective is to maintain the cylinders in such a manner that the DUF 6 may eventually be converted to a less hazardous material for final disposition. An important task in the DUF 6 cylinders management project is determining how much corrosion of the walls can be tolerated before the cylinders are in danger of being damaged during routine handling and shipping operations. Another task is determining how to handle cylinders that have already been damaged in a manner that will minimize the chance that a breach will occur or that the size of an existing breach will be significantly increased. A number of finite element stress analysis (FESA) calculations have been done to analyze the stresses for three conditions: (1) while the cylinder is being lifted, (2) when a cylinder is resting on two cylinders under it in the customary two-tier stacking array, and (3) when a cylinder is resting on tis chocks on the ground. Various documents describe some of the results and discuss some of the methods whereby they have been obtained. The objective of the present report is to document as many of the FESA cases done at Oak Ridge for 14-ton thin-wall cylinders as possible, giving results and a description of the calculations in some detail

  14. Mass transfer effects in feeder flow-accelerated corrosion wall thinning

    International Nuclear Information System (INIS)

    Pietralik, J.

    2008-01-01

    Flow conditions play a dominant role in Flow-Accelerated Corrosion (FAC) under certain conditions, e.g., in CANDU feeders. While chemistry and materials set the overall potential for FAC, flow conditions determine the local distribution of wall thinning. Recent plant data of feeders and laboratory tests confirms that there is a close relationship between local flow conditions, expressed by mass transfer coefficient, and FAC rate in CANDU feeder bends. The knowledge of local effects can be useful for minimizing the number of inspected components, predicting the location of the highest FAC rate for a given piping component, and determining what components or feeders should be replaced. A similar evaluation applies also to FAC in heat transfer equipment such as heat exchangers and steam generators. The objective of this paper is to examine the relationship between FAC rate and local mass transfer parameters. For FAC where the flow is dominant, the FAC rate is proportional to mass flux of ferrous ions. The mass flux is the product of the mass transfer coefficient and the concentration difference, or degree of saturation. The mass transfer coefficient describes the intensity of the transport of corrosion products (ferrous ions) from the oxide-water interface into the bulk water. Therefore, this parameter can be used for predicting the local distribution of FAC rate in the mass-transfer controlled FAC. The degree of saturation reduces the mass flux, thus reducing the FAC rate. This effect can be significant in long piping, e.g., in outlet feeders. The paper presents plant and laboratory evidence for the relationship between local mass transfer conditions and the FAC rate. It shows correlations for mass transfer coefficient in components that are highly susceptible to FAC and most important flow parameters that affect mass transfer coefficient. The role of surface roughness, wall shear stress, and local turbulence is also discussed. (author)

  15. Biliary peritonitis caused by a leaking T-tube fistula disconnected at the point of contact with the anterior abdominal wall: a case report

    Directory of Open Access Journals (Sweden)

    Nikolić Marko

    2008-09-01

    Full Text Available Abstract Introduction Operations on the common bile duct may lead to potentially serious complications such as biliary peritonitis. T-tube insertion is performed to reduce the risk of this occurring postoperatively. Biliary leakage at the point of insertion into the common bile duct, or along the fistula, can sometimes occur after T-tube removal and this has been reported extensively in the literature. We report a case where the site at which the T-tube fistula leaked proved to be the point of contact between the fistula and the anterior abdominal wall, a previously unreported complication. Case presentation A 36-year-old sub-Saharan African woman presented with gallstone-induced pancreatitis and, once her symptoms settled, laparoscopic cholecystectomy was performed, common bile duct stones were removed and a T-tube was inserted. Three weeks later, T-tube removal led to biliary peritonitis due to the disconnection of the T-tube fistula which was recannulated laparoscopically using a Latex drain. Conclusion This case highlights a previously unreported mechanism for bile leak following T-tube removal caused by detachment of a fistula tract at its contact point with the anterior abdominal wall. Hepatobiliary surgeons should be aware of this mechanism of biliary leakage and the use of laparoscopy to recannulate the fistula.

  16. Investigation on Nano composite Membrane of Multi walled Carbon Nano tube Reinforced Polycarbonate Blend for Gas Separation

    International Nuclear Information System (INIS)

    Kausar, A.

    2016-01-01

    Carbon nano tube has been explored as a nano filler in high performance polymeric membrane for gas separation. In this regard, nano composite membrane of polycarbonate (PC), poly(vinylidene fluoride-co-hexafluoropropylene) (PVFHFP), and multi walled carbon nano tube (MWCNT) was fabricated via phase inversion technique. Poly (ethylene glycol) (PEG) was employed for the compatibilization of the blend system. Two series of PC/PVFHFP/PEG were developed using purified P-MWCNT and acid functional A-MWCNT nano filler. Scanning and transmission electron micrographs have shown fine nano tube dispersion and wetting by matrix, compared with the purified system. Tensile strength and Young s modulus of PC/PVFHFP/PEG/MWCNT-A 1-5 were found to be in the range of 63.6-72.5 MPa and 110.6-122.1 MPa, respectively. The nano composite revealed 51% increase in Young s modulus and 28% increase in tensile stress relative to the pristine blend. The A-MWCNT was also effective in enhancing the perm selectivity αCO 2 /N 2 (31.2-39.9) of nano composite membrane relative to the blend membrane (21.6). The permeability ρCO 2 of blend was 125.6 barrer; however, the functional series had enhancedρCO 2 values ranging from 142.8 to 186.6 barrer. Moreover, A-MWCNT loading improved the gas diffusivity of PC/PVFHFP/PEG/MWCNT-A 1-5; however, filler content did not significantly influence the CO 2 and N 2 solubility.

  17. Non-linear analysis of the behaviour of a thin and squat reinforced concrete wall on a seismic table

    International Nuclear Information System (INIS)

    Mazars, J.; Ghavamian, S.; Ile, N.; Reynouard, J.M.

    1998-01-01

    This work concerns the modeling and analysis of the seismic behaviour of a thin reinforced concrete wall using an experiment performed by the NUPEC (Nuclear Power Engineering Corporation) Japanese organisation with the Tadotsu seismic table. The wall with a height/width ratio close to 1, has its extremities stiffened and its base embedded. The wall, loaded on its top with a 122 t weight, is submitted to several seismic levels up to its collapse. A non-linear seismic analysis and different 2-D and 3-D finite elements modeling were used to simulate the behaviour of the structure submitted to a strong dynamic shear. The results presented in this paper belong to the ''Seismic Shear Wall Standard Problem'' benchmark jointly organized the NUPEC and OECD organizations. (J.S.)

  18. Coupled Static and Dynamic Buckling Modelling of Thin-Walled Structures in Elastic Range Review of Selected Problems

    Directory of Open Access Journals (Sweden)

    Kołakowski Zbigniew

    2016-06-01

    Full Text Available A review of papers that investigate the static and dynamic coupled buckling and post-buckling behaviour of thin-walled structures is carried out. The problem of static coupled buckling is sufficiently well-recognized. The analysis of dynamic interactive buckling is limited in practice to columns, single plates and shells. The applications of finite element method (FEM or/and analytical-numerical method (ANM to solve interaction buckling problems are on-going. In Poland, the team of scientists from the Department of Strength of Materials, Lodz University of Technology and co-workers developed the analytical-numerical method. This method allows to determine static buckling stresses, natural frequencies, coefficients of the equation describing the post-buckling equilibrium path and dynamic response of the plate structure subjected to compression load and/or bending moment. Using the dynamic buckling criteria, it is possible to determine the dynamic critical load. They presented a lot of interesting results for problems of the static and dynamic coupled buckling of thin-walled plate structures with complex shapes of cross-sections, including an interaction of component plates. The most important advantage of presented analytical-numerical method is that it enables to describe all buckling modes and the post-buckling behaviours of thin-walled columns made of different materials. Thin isotropic, orthotropic or laminate structures were considered.

  19. Failure analysis of large tube of maraging steel 350 (145 mm dia, 1 mm wall thickness)

    International Nuclear Information System (INIS)

    Shamim, A.

    1997-01-01

    A steady of opening mode of crack initiation in maraging steel 350 rotor tubes aged and rolled condition (1 mm thick sheet) has been constructed, with the aid of a (NEOPHOT 2) microscope. Observations were made from several orientations including the top view of the specimen which showed the profile and the edge view of the specimen which showed the entire notch front along the specimen thickness. It was found that the edge view exhibited the first signs of permanent deformation. These changes took the form of deformation bends which were aligned in direction of the tensile axis and apparently defined limiting regions of homogeneous slip. It is felt that the appearance of microcracks at loads approaching the breaking strength was of fundamental importance in the formation of the final fracture surface. Many of these microcracks were initiated at intermetallic particles and other metallurgically weak regions on the notch surface. (author)

  20. Fracture mechanics of thin wall cylindrical pressure vessels: an interim review

    International Nuclear Information System (INIS)

    Kurtz, R.J.; Olson, N.J.

    1977-08-01

    The report is a result of activities in the LMFBR Fuel Rod Transient Performance Program sponsored by the LMFBR Branch of the Division of Project Management, U.S. Nuclear Regulatory Commission. One of the objectives is to develop predictions relative to the length, direction, and rate of growth of cladding rips subsequent to (or concurrent with) the initial cladding breach during unprotected transients. To provide a basis for evaluation, Battelle, Pacific Northwest Laboratories has reviewed most available fracture mechanics assessments relative to thin-wall cylindrical pressure vessels. The purpose of the report is to review the various fracture mechanics models and to describe the pertinent fracture parameters. It is intended to provide a formal basis for assessing future analytical predictions of fracture behavior of materials exposed to transient LMFBR thermal and mechanical loading conditions. In addition, the report is expected to provide reference material for evaluating or developing experimental programs required to properly address the problem of predicting fracture behavior of materials during transient events

  1. Enhanced forward osmosis from chemically modified polybenzimidazole (PBI) nanofiltration hollow fiber membranes with a thin wall

    KAUST Repository

    Wang, Kai Yu; Yang, Qian; Chung, Tai-Shung; Rajagopalan, Raj

    2009-01-01

    To develop high-flux and high-rejection forward osmosis (FO) membranes for water reuses and seawater desalination, we have fabricated polybenzimidazole (PBI) nanofiltration (NF) hollow fiber membranes with a thin wall and a desired pore size via non-solvent induced phase inversion and chemically cross-linking modification. The cross-linking by p-xylylene dichloride can finely tune the mean pore size and enhance the salt selectivity. High water permeation flux and improved salt selectivity for water reuses were achieved by using the 2-h modified PBI NF membrane which has a narrow pore size distribution. Cross-linking at a longer time produces even a lower salt permeation flux potentially suitable for desalination but at the expense of permeation flux due to tightened pore sizes. It is found that draw solution concentration and membrane orientations are main factors determining the water permeation flux. In addition, effects of membrane morphology and operation conditions on water and salt transport through membrane have been investigated. © 2008 Elsevier Ltd. All rights reserved.

  2. A single-walled carbon nanotube thin film-based pH-sensing microfluidic chip.

    Science.gov (United States)

    Li, Cheng Ai; Han, Kwi Nam; Pham, Xuan-Hung; Seong, Gi Hun

    2014-04-21

    A novel microfluidic pH-sensing chip was developed based on pH-sensitive single-walled carbon nanotubes (SWCNTs). In this study, the SWCNT thin film acted both as an electrode and a pH-sensitive membrane. The potentiometric pH response was observed by electronic structure changes in the semiconducting SWCNTs in response to the pH level. In a microfluidic chip consisting of a SWCNT pH-sensing working electrode and an Ag/AgCl reference electrode, the calibration plot exhibited promising pH-sensing performance with an ideal Nernstian response of 59.71 mV pH(-1) between pH 3 and 11 (standard deviation of the sensitivity is 1.5 mV pH(-1), R(2) = 0.985). Moreover, the SWCNT electrode in the microfluidic device showed no significant variation at any pH value in the range of the flow rate between 0.1 and 15 μl min(-1). The selectivity coefficients of the SWCNT electrode revealed good selectivity against common interfering ions.

  3. Failure pressure of straight pipe with wall thinning under internal pressure

    International Nuclear Information System (INIS)

    Kamaya, Masayuki; Suzuki, Tomohisa; Meshii, Toshiyuki

    2008-01-01

    The failure pressure of pipe with wall thinning was investigated by using three-dimensional elastic-plastic finite element analyses (FEA). With careful modeling of the pipe and flaw geometry in addition to a proper stress-strain relation of the material, FEA could estimate the precise burst pressure obtained by the tests. FEA was conducted by assuming three kinds of materials: line pipe steel, carbon steel, and stainless steel. The failure pressure obtained using line pipe steel was the lowest under the same flaw size condition, when the failure pressure was normalized by the value of unflawed pipe defined using the flow stress. On the other hand, when the failure pressure was normalized by the results of FEA obtained for unflawed pipe under various flaw and pipe configurations, the failure pressures of carbon steel and line pipe steel were almost the same and lower than that of stainless steel. This suggests that the existing assessment criteria developed for line pipe steel can be applied to make a conservative assessment of carbon steel and stainless steel

  4. Enhanced forward osmosis from chemically modified polybenzimidazole (PBI) nanofiltration hollow fiber membranes with a thin wall

    KAUST Repository

    Wang, Kai Yu

    2009-04-01

    To develop high-flux and high-rejection forward osmosis (FO) membranes for water reuses and seawater desalination, we have fabricated polybenzimidazole (PBI) nanofiltration (NF) hollow fiber membranes with a thin wall and a desired pore size via non-solvent induced phase inversion and chemically cross-linking modification. The cross-linking by p-xylylene dichloride can finely tune the mean pore size and enhance the salt selectivity. High water permeation flux and improved salt selectivity for water reuses were achieved by using the 2-h modified PBI NF membrane which has a narrow pore size distribution. Cross-linking at a longer time produces even a lower salt permeation flux potentially suitable for desalination but at the expense of permeation flux due to tightened pore sizes. It is found that draw solution concentration and membrane orientations are main factors determining the water permeation flux. In addition, effects of membrane morphology and operation conditions on water and salt transport through membrane have been investigated. © 2008 Elsevier Ltd. All rights reserved.

  5. Aerodynamics of a thin airfoil flying over and in proximity to a wavy-wall surface. ; Lifting surface theory

    Energy Technology Data Exchange (ETDEWEB)

    Ando, S [Nagoya University, Nagoya (Japan); Ichikawa, M [Government Industrial Research Institute, Nagoya, Nagoya (Japan)

    1991-05-04

    Aerodynamic characteristics of a thin airfoil flying over and in proximity to a wavy-wall surface such as uneven ground or water surface were analyzed two-dimensionally by lifting surface theory in the simplest fundamental case only. The theoretical equation was simplified assuming that flow is inviscid and incompressible, all disturbances are sufficiently small, the wall surface is sinusoidal and rigid, and the wall moves in the same direction as free stream but with a constant velocity different from that of the stream. The equation was verified in the case where an airfoil with a constant angle-of-attack flies over a flat ground surface, and calculations were made with a set of important parameters such as mean airfoil height from the wall, wave length of the wall surface and the wall velocity. The whole effect of wavy wall proximity was divided into the first and second-order ground effects. The first one was just Kemp{prime}s upwash problem, and the second one was revealed through the present study which becomes significant for lower airfoil heights. 18 refs., 5 figs.

  6. The local domain wall position in ferromagnetic thin wires: simultaneous measurement of resistive and transverse voltages at multiple points

    International Nuclear Information System (INIS)

    Hanada, R.; Sugawara, H.; Aoki, Y.; Sato, H.; Shigeto, K.; Shinjo, T.; Ono, T.; Miyajima, H.

    2002-01-01

    We have simultaneously measured the field dependences of voltages at multiple pairs of resistance and transverse voltage probes in ferromagnetic wires (with either magnetic or non-magnetic voltage probes). Both the resistive (through the giant magnetoresistance and anisotropic magnetoresistance) and transverse voltages (through the planar Hall effect) exhibit abrupt jumps, reflecting discrete motion of domain walls or rotations of magnetization. Voltage probes, even if non-magnetic, are found to affect the jump fields depending on the sample conditions. We demonstrate that the specific information on the domain (wall) motion along a thin ferromagnetic wire could be obtained from the jump fields. (author)

  7. Technical note: Influence of surface roughness and local turbulence on coated-wall flow tube experiments for gas uptake and kinetic studies

    Directory of Open Access Journals (Sweden)

    G. Li

    2018-02-01

    Full Text Available Coated-wall flow tube reactors are frequently used to investigate gas uptake and heterogeneous or multiphase reaction kinetics under laminar flow conditions. Coating surface roughness may potentially distort the laminar flow pattern, induce turbulence and introduce uncertainties in the calculated uptake coefficient based on molecular diffusion assumptions (e.g., Brown/Cooney–Kim–Davis (CKD/Knopf–Pöschl–Shiraiwa (KPS methods, which has not been fully resolved in earlier studies. Here, we investigate the influence of surface roughness and local turbulence on coated-wall flow tube experiments for gas uptake and kinetic studies. According to laminar boundary theory and considering the specific flow conditions in a coated-wall flow tube, we derive and propose a critical height δc to evaluate turbulence effects in the design and analysis of coated-wall flow tube experiments. If a geometric coating thickness δg is larger than δc, the roughness elements of the coating may cause local turbulence and result in overestimation of the real uptake coefficient (γ. We further develop modified CKD/KPS methods (i.e., CKD-LT/KPS-LT to account for roughness-induced local turbulence effects. By combination of the original methods and their modified versions, the maximum error range of γCKD (derived with the CKD method or γKPS (derived with the KPS method can be quantified and finally γ can be constrained. When turbulence is generated, γCKD or γKPS can bear large difference compared to γ. Their difference becomes smaller for gas reactants with lower uptake (i.e., smaller γ and/or for a smaller ratio of the geometric coating thickness to the flow tube radius (δg ∕ R0. On the other hand, the critical height δc can also be adjusted by optimizing flow tube configurations and operating conditions (i.e., tube diameter, length, and flow velocity, to ensure not only unaffected laminar flow patterns but also other specific requirements for an

  8. CONSTRUCTIVE ASPECTS INFLUENCE ON STIFFNESS OF DIAPHRAGM WALLS IN FRAME CONSTRUCTIONS WITH (LIGHT STEEL THINWALLED STRUCTURES

    Directory of Open Access Journals (Sweden)

    M. V. Savytskyi

    2010-10-01

    Full Text Available The dependences of influence of structural features of diaphragms of lightweight steel framing braced wall structures on their stiffness are determined. On the basis of dependences the procedure for estimation of stiffness of a diaphragm of any configuration that allows making decisions for maintenance of building stiffness is developed.

  9. Physical properties of SnS thin films grown by hot wall deposition

    International Nuclear Information System (INIS)

    Gremenok, V.; Ivanov, V.; Bashkirov, S.; Unuchak, D.; Lazenka, V.; Bente, K.; Tashlykov, I.; Turovets, A.

    2010-01-01

    Full text : Recently, considerable effort has been invested to gain a better and deeper knowledge of structural and physical properties of metal chalcogenide semiconductors because of their potential application in electrical and photonic devices. Among them, tin sulphide (SnS) has attracted attention because of band gap of 1.3 eV and an absorption coefficient greater than 10 4 cm - 1. Additionally, by using tin sulfide compounds for photovoltaic devices, the production costs are decreased, because these materials are cheap and abundant in nature. For the sythesis of SnS thin films by hot wall deposition, SnS ingots were used as the source materials synthesized from high purity elements (99.999 percent). The thin films were grown onto glass at substrate temperatures between 220 and 380 degrees Celsium. The thickness of the films was in the range of 1.0 - 2.5 μm. The crystal structure and crystalline phases of the materials were studied by XRD using a Siemens D-5000 diffractometer with CuK α (λ = 1.5418 A) radiation. In order to consider instrumental error, the samples were coated by Si powder suspended in acetone. The composition and surface morphology of thin films were investigated by electron probe microanalysis (EPMA) using a CAMECA SX-100, a scanning electron microscope JEOL 6400 and an atomic force microscope (AFM, Model: NT 206), respectively. Depth profiling was performed by Auger electron spectroscopy (AES) using a Perkin Elmer Physical Electronics 590. The electrical resistivity was studied by van der Pauw four-probe technique using silver paste contact. The optical transmittance was carried out using a Varian Cary 50 UV - VIS spectrophotometer in the range 500 - 2000 nm. The as-grown films exhibited a composition with a Sn/S at. percent ratio of 1.06. The AES depth profiles revealed relatively uniform composition through the film thickness. The XRD analysis of the SnS films showed that they were monophase (JCPDS 39-0354), polycrystalline with

  10. Development of austenitic stainless steel tubes for nuclear reactor cladding

    International Nuclear Information System (INIS)

    Padilha, A.F.; Ferreira, P.I.; Andrade, P.I.; Andrade, A.H.P. de; Meyerhof, S.; Mauricio, J.

    1984-01-01

    In the development of thin wall tubes for nuclear reactor fuel cladding applications, a great number of activities, related to the fabrication process as the qualification are involved. A test program was envisaged to verify the quality of seam welded stainless steel tubes (AISI 304), obtained as a result of an effort by the IPEN-CNEN/SP and the brazilian industry. The relevant aspects involved in the preparation of the tubes and some preliminary test results are presented. (Author) [pt

  11. Deposition Time and Thermal Cycles of Fabricating Thin-wall Steel Parts by Double Electrode GMAW Based Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Yang Dongqing

    2017-01-01

    Full Text Available The deposition time for fabricating the thin-wall part as well as the peak temperature of the substrate during the process was analyzed in the double electrode gas metal arc welding (DE-GMAW based additive manufacturing (AM. The total deposition time and the interlayer idle time of the manufacturing process decreased with the increasing of the bypass current under the same interlayer temperature and the same deposition rate. The thermal cycling curves illustrated that the peak temperature of the substrate was lower in the DE-GMAW base AM under the same conditions. When depositing the thin-wall parts, the DE-GMAW based AM can reduce the heat input to the substrate and improve the fabrication efficiency, compared with the GMAW based AM.

  12. Strength tests of thin-walled elliptic duralumin cylinders in pure bending and in combined pure bending and torsion

    Science.gov (United States)

    Lundquist, Eugene E; Stowell, Elbridge Z

    1942-01-01

    An analysis is presented of the results of tests made by the Massachusetts Institute of Technology and by the National Advisory Committee for Aeronautics on an investigation of the strength of thin-walled circular and elliptic cylinders in pure bending and in combined torsion and bending. In each of the loading conditions, the bending moments were applied in the plane of the major axis of the ellipse.

  13. Comparison of characteristics parameters in the evaluation of wall thickness diminishing in admiralty brass tubes of the steam condenser, tested by eddy currents

    International Nuclear Information System (INIS)

    Obrutsky, Alba E.; Mendez, Jorge A.; Acosta, Cesar D.; Scopelliti, Jose D.

    1999-01-01

    This work is aimed to appraise the measure of the wall thickness diminishing in the signals evaluation obtained in the inspection of steam condenser by eddy currents. In the analysis of the obtained signals were observed in the brass tubes a great quantity of internal defects whose signal indicates that there were diminishing of the wall thickness between 80% and 100%. With all this information and analyzing the data acquired, the tubes with more important indications were selected to make a more exhaustive study of the found defectology. As first test, it was measured the thickness of the worn tubes, comparing them with the original ones that are in stock. It was verified that the tubes separated for this study presented a 30% less thickness in comparison with the new tubes. A semiquantitative chemical test (EDAX) was made to verify if it was the same material. One of the extracted tubes (066 Y1) was reinspected in order to isolate the area with indications. Once this was performed, it was decided to cut the tube to make a visual inspection and to evaluate to what type of defect corresponds to the signals obtained. In the metallography it was confirm that it was a horseshoe type defect. When performing a dimensional control test of the found real defect, it was checked that the information obtained by eddy currents regarding the diminishing of the wall thickness diminishing was valid. At a last stage of the test, it was proceed to make an study and verification of the used parameters, probes, standards and finally determine which shall be the convenient modifications to minimize errors. (author)

  14. Improvement of Electrical Conductivity of Single-Walled Carbon Nano tube Network Using Particle Irradiation

    International Nuclear Information System (INIS)

    Lim, Suntaek; Kim, Gonho

    2010-01-01

    Substitution for Indium Tin Oxide of transparent electrode Applications : Flat panel displays, Touch panel, Solar cell, EM wave shielding... For very low energy of 20 eV and 90 eV, argon ion irradiations, the surface of SWCNT bundles were sputtered and thinned the diameter of the bundle. With increasing the incident ion energy as 7.5 keV, SWCNT bundles were networked by amorphization of cross welded CNTs. → Less damage can be obtained from higher energy of irradiated particle due to less collision cross section. For 10 MeV proton and 800 keV electron irradiations, there are no severe damages. Electron irradiation is more effective on network with less damage than that of ion irradiation. → Network process can be proceeded with the generation of free carbon, the migration of free carbon on CNT and reconstruction of the cross linked CNTs, which processes require the latent energy on CNT body after collision. It can be controlled by the energy and dose of irradiation particle

  15. Stiffness Matrix of Thin-Walled Open Bar Subject to Bending, Bending Torsion and Shift of Cross Section Middle Surface

    Science.gov (United States)

    Panasenko, N. N.; Sinelschikov, A. V.

    2017-11-01

    One of the main stages in the analysis of complex 3D structures and engineering constructions made of thin-walled open bars using FEM is a stiffness matrix developing. Taking into account middle surface shear deformation caused by the work of tangential stresses in the formula to calculate a potential energy of thin-walled open bars, the authors obtain an important correction at calculation of the bar deformation and fundamental frequencies. The results of the analysis of the free end buckling of a cantilever H-bar under plane bending differ from exact solution by 0.53%. In the course of comparison of the obtained results with the cantilever bar buckling regardless the middle surface shear deformation, an increase made 16.6%. The stiffness matrix of a thin-walled open bar developed in the present work can be integrated into any software suite using FEM for the analysis of complex 3-D structures and engineering constructions with n-freedoms.

  16. Basic Principles of Thin-Walled Open Bars Taking into Account Where Influence Shifts of Cross Sections are Concerned

    Science.gov (United States)

    Panasenko, N. N.; Sinelschikov, A. V.

    2017-11-01

    The finite element method is considered to be the most effective in relation to the calculation of strength and stability of buildings and engineering constructions. As a rule, for the modelling of supporting 3-D frameworks, finite elements with six degrees of freedom are used in each of the nodes. In practice, such supporting frameworks represent the thin-walled welded bars and hot-rolled bars of open and closed profiles in which cross-sectional deplanation must be taken into account. This idea was first introduced by L N Vorobjev and brought to one of the easiest variants of the thin-walled bar theory. The development of this approach is based on taking into account the middle surface shear deformation and adding the deformations of a thin-walled open bar to the formulas for potential and kinetic energy; these deformations depend on shearing stress and result in decreasing the frequency of the first tone of fluctuations to 13%. The authors of the article recommend taking into account this fact when calculating fail-proof dynamic systems.

  17. Characterization of non-calcareous 'thin' red clay from south-eastern Brazil: applicability in wall tile manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, S. J.G.; Holanda, J. N.F., [Grupo de Materiais Ceramicos - LAMAV-CCT, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ (Brazil)

    2012-04-15

    In this work the use of 'thin' red clay from south-eastern Brazil (Campos dos Goytacazes, RJ) as raw material for the manufacture of wall tile was investigated. A wide range of characterization techniques was employed, including X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), grain-size analysis, and thermogravimetric analysis. The wall tile body was prepared by the dry process. The tile pieces were uniaxially pressed and fired between 1080 - 1180 deg C using a fast-firing cycle. The following technological properties were determined: linear shrinkage, water absorption, apparent density, and flexural strength. The development of the microstructure was followed by SEM and XRD analyses. It was found that the 'thin' red clay is kaolinitic type containing a substantial amount of quartz. The results also showed that the 'thin' red clay could be used in the manufacture of wall tiles, as they present properties compatible with those specified for class BIII of ISO 13006 standard. (author)

  18. Differential Hall-sensor Pulsed Eddy Current Probe for the Detection of Wall thinning in an Insulated Stainless Steel Pipe

    International Nuclear Information System (INIS)

    Park, D. G.; Angani, Chandra S.; Cheong, Y. M.; Kim, C. G.

    2010-01-01

    The local wall thinning is one of the most important factors to limit the life-extension of large structures, such as the pipe lines in the NPPs. The pipelines are covered with a thermal insulator for low thermal loss. The PEC testing is the promising technological approach to the NDT, and it has been principally developed for the measurement of surface flaws, subsurface flaws and corrosion. In the pulsed eddy current (PEC) technique, the excitation coil is driven by repeated pulses. According to the skin - depth relationship multiple frequency components penetrate to different depths, hence the PEC technique has the potential for bringing up deeper information about the tested sample. Because of the potential advantages of the PEC, prevalent investigations on this technique have been done. In the present study a differential probe which is used in the Pulsed Eddy Current (PEC) system has been fabricated for the detection of wall thinning of insulated pipelines in a nuclear power plant (NPP). This technique can be used as a potential tool to detect the corrosion or the wall thinning of the pipelines without removing the insulation

  19. The analysis of thin walled composite laminated helicopter rotor with hierarchical warping functions and finite element method

    Science.gov (United States)

    Zhu, Dechao; Deng, Zhongmin; Wang, Xingwei

    2001-08-01

    In the present paper, a series of hierarchical warping functions is developed to analyze the static and dynamic problems of thin walled composite laminated helicopter rotors composed of several layers with single closed cell. This method is the development and extension of the traditional constrained warping theory of thin walled metallic beams, which had been proved very successful since 1940s. The warping distribution along the perimeter of each layer is expanded into a series of successively corrective warping functions with the traditional warping function caused by free torsion or free bending as the first term, and is assumed to be piecewise linear along the thickness direction of layers. The governing equations are derived based upon the variational principle of minimum potential energy for static analysis and Rayleigh Quotient for free vibration analysis. Then the hierarchical finite element method is introduced to form a numerical algorithm. Both static and natural vibration problems of sample box beams are analyzed with the present method to show the main mechanical behavior of the thin walled composite laminated helicopter rotor.

  20. Construction of Earthquake - Proof Safety Evaluaiton Methods for Pipes with Wall Thinning

    International Nuclear Information System (INIS)

    Miyano, H.; Sekimura, N.; Takizawa, M.; Mastumoto, M.

    2012-01-01

    Since the Fukushima Dai-ichi accident, the importance of 'system safety' has been recognized anew. Particularly, system safety assessment of plants in operation from the various degradation perspectives, specifically, transition of time is very important. Accordingly, assessment on degradation will focus on the degradation of functions with passing of time, combined with the changes in the safety standards and concept of safety. Reliability assessment will be made on the consolidation of important functions, and not on individual components. The boundary function of the system will be one of the focus of this study. For the purpose of reliability assessment on the system by evaluating and quantifying the damage (or rupture) risk of piping - method for confirming the integrity of the system through the assessment on the damage (rupture) risk of the system when an external force caused by an earthquake is applied (the system is sound if the damage (rupture) risk is small) was examined on the basis of the prediction results for each of the parts in pipe wall thinning. In the next phase, the prediction results will be verified by tests, whereby, the improvement in reliability will be confirmed, and a combined assessment will be made in relation to the degradation factors of other systems. 'System safety' assessment method of plants in operation will be developed in a manner where a comprehensive assessment on the safety of the entire plant can be made. Specifically, the changes in the conditions, such as material degradations that degrade performance will be assessed on the entire system. Whereby, the risk caused by functional failure (damage) due to degradation will be regarded as the total of risk in the assessment. A framework on safety assessment will be structured, where the degree of safety will be measured by functional degradation, taking into consideration the changes made in the safety standards up to present. (author)

  1. A Thin detector with ionization tubes for high energy electrons and photons

    International Nuclear Information System (INIS)

    Amatuni, Ts. A.; Denisov, S.P.; Krasnokutsky, R.N.; Lebedenko, V.N.; Shuvalov, R.S.

    1981-01-01

    A possibility to measure the energy of electrons and photons with a simple detector, consisting of a lead convertor and ionization tubes filled with pure argon, has been studied. The measurements have been performed in a 26.6 GeV electron beam. The best energy resolution approximately 16% was achieved for the convertor thickness 40 mm and argon pressure > 20 atm. The performance of the detector in magnetic field up to 16 kGs has been also studied. It turned out that the mean pulse height rises approximately linearly with increasing magnetic field and becomes flat at H approximately 10 kGs. This behaviour is the same for magnetic field perpendicular and parallel with respect to the ionization tubes. The energy resolution depends weakly on the magnetic field. Ionization tubes filled with argon or xenon under high pressure may be used for minimum ionizing particle detection [ru

  2. Control and optimization of solute transport in a thin porous tube

    KAUST Repository

    Griffiths, I. M.; Howell, P. D.; Shipley, R. J.

    2013-01-01

    differentials upon the dispersive solute behaviour are investigated. The model is used to explore the control of solute transport across the membrane walls via the membrane permeability, and a parametric expression for the permeability required to generate a

  3. Augmentative effect of pulsatility on the wall shear stress in tube flow.

    Science.gov (United States)

    Nakata, M; Tatsumi, E; Tsukiya, T; Taenaka, Y; Nishimura, T; Nishinaka, T; Takano, H; Masuzawa, T; Ohba, K

    1999-08-01

    Wall shear stress (WSS) has been considered to play an important role in the physiological and metabolic functions of the vascular endothelial cells. We investigated the effects of the pulse rate and the maximum flow rate on the WSS to clarify the influence of pulsatility. Water was perfused in a 1/2 inch transparent straight cylinder with a nonpulsatile centrifugal pump and a pulsatile pneumatic ventricular assist device (VAD). In nonpulsatile flow (NF), the flow rate was changed 1 to 6 L/min by 1 L/min increments to obtain standard values of WSS at each flow rate. In pulsatile flow (PF), the pulse rate was controlled at 40, 60, and 80 bpm, and the maximum flow rate was varied from 3.3 to 12.0 L/min while the mean flow rate was kept at 3 L/min. The WSS was estimated from the velocity profile at measuring points using the laser illuminated fluorescence method. In NF, the WSS was 12.0 dyne/cm2 at 3 L/min and 33.0 dyne/cm2 at 6 L/min. In PF, the pulse rate change with the same mean, and the maximum flow rate did not affect WSS. On the other hand, the increase in the maximum flow rate at the constant mean flow rate of 3 L/min augmented the mean WSS from 13.1 to 32.9 dyne/cm2. We concluded that the maximum flow rate exerted a substantial augmentative effect on WSS, and the maximum flow rate was a dominant factor of pulsatility in this effect.

  4. The Apical Actin Fringe Contributes to Localized Cell Wall Deposition and Polarized Growth in the Lily Pollen Tube1[W][OPEN

    Science.gov (United States)

    Rounds, Caleb M.; Hepler, Peter K.; Winship, Lawrence J.

    2014-01-01

    In lily (Lilium formosanum) pollen tubes, pectin, a major component of the cell wall, is delivered through regulated exocytosis. The targeted transport and secretion of the pectin-containing vesicles may be controlled by the cortical actin fringe at the pollen tube apex. Here, we address the role of the actin fringe using three different inhibitors of growth: brefeldin A, latrunculin B, and potassium cyanide. Brefeldin A blocks membrane trafficking and inhibits exocytosis in pollen tubes; it also leads to the degradation of the actin fringe and the formation of an aggregate of filamentous actin at the base of the clear zone. Latrunculin B, which depolymerizes filamentous actin, markedly slows growth but allows focused pectin deposition to continue. Of note, the locus of deposition shifts frequently and correlates with changes in the direction of growth. Finally, potassium cyanide, an electron transport chain inhibitor, briefly stops growth while causing the actin fringe to completely disappear. Pectin deposition continues but lacks focus, instead being delivered in a wide arc across the pollen tube tip. These data support a model in which the actin fringe contributes to the focused secretion of pectin to the apical cell wall and, thus, to the polarized growth of the pollen tube. PMID:25037212

  5. Electromechanical properties of multi-walled carbon nano-tubes; Proprietes electromecaniques des nanotubes de carbone multiparois

    Energy Technology Data Exchange (ETDEWEB)

    Lefevre, R

    2005-12-15

    In this PhD thesis, we tackled theoretically and experimentally the problem of designing nano-electromechanical systems (NEMS) based on multi-walled carbon nano-tubes (MWCNTs). Furthermore, we applied our know-how to perform components like switches. We developed a theoretical model to describe the deflection of a suspended MWCNT stressed by an attractive electrostatic force. Our model highlights a scaling law linking up the electrostatic deflection, geometrical, electrical and physical parameters of MWCNTs based NEMS. This result constitutes a practical designing tool because it predicts their electromechanical behaviour on a 'large' range of operational parameters. At the same time, we developed several processes to fabricate nano-structures incorporating a suspended MWCNT electrostatically actuated. Among these different structures, the simplest was used to develop a method for probing electromechanical properties of MWCNTs. Our method is based on atomic force microscopy measurements on a doubly clamped suspended MWCNT electrostatically deflected by a drive voltage. These measurements show clearly for different MWCNTs (different diameter and length) the existence of such scaling law in agreement with the continuum model prediction. From these results, we extracted the Young's modulus of MWCNTs. For diameters smaller than 30 nm it is constant and its average value equals 400 GPa. Above, we observed a strong decrease that could be explained by the entry in a non-linear regime of deformation. Finally, we show the realization of an electromechanical switch based on a suspended MWCNT which presents good switching behaviour. (author)

  6. Electromechanical properties of multi-walled carbon nano-tubes; Proprietes electromecaniques des nanotubes de carbone multiparois

    Energy Technology Data Exchange (ETDEWEB)

    Lefevre, R.

    2005-12-15

    In this PhD thesis, we tackled theoretically and experimentally the problem of designing nano-electromechanical systems (NEMS) based on multi-walled carbon nano-tubes (MWCNTs). Furthermore, we applied our know-how to perform components like switches. We developed a theoretical model to describe the deflection of a suspended MWCNT stressed by an attractive electrostatic force. Our model highlights a scaling law linking up the electrostatic deflection, geometrical, electrical and physical parameters of MWCNTs based NEMS. This result constitutes a practical designing tool because it predicts their electromechanical behaviour on a 'large' range of operational parameters. At the same time, we developed several processes to fabricate nano-structures incorporating a suspended MWCNT electrostatically actuated. Among these different structures, the simplest was used to develop a method for probing electromechanical properties of MWCNTs. Our method is based on atomic force microscopy measurements on a doubly clamped suspended MWCNT electrostatically deflected by a drive voltage. These measurements show clearly for different MWCNTs (different diameter and length) the existence of such scaling law in agreement with the continuum model prediction. From these results, we extracted the Young's modulus of MWCNTs. For diameters smaller than 30 nm it is constant and its average value equals 400 GPa. Above, we observed a strong decrease that could be explained by the entry in a non-linear regime of deformation. Finally, we show the realization of an electromechanical switch based on a suspended MWCNT which presents good switching behaviour. (author)

  7. Flow instability research on steam generator with straight double-walled heat transfer tube for FBR. Pressure drop under high pressure condition

    International Nuclear Information System (INIS)

    Liu, Wei; Tamai, Hidesada; Yoshida, Hiroyuki; Takase, Kazuyuki; Hayafune, Hiroki; Futagami, Satoshi; Kisohara, Naoyuki

    2008-01-01

    For the Steam Generator (SG) with straight double-walled heat transfer tube that used in sodium cooled Faster Breeder Reactor, flow instability is one of the most important items need researching. As the first step of the research, thermal hydraulics experiments were performed under high pressure condition in JAEA with using a straight tube. Pressure drop, heat transfer coefficients and void fraction data were derived. This paper evaluates the pressure drop data with TRAC-BF1 code. The Pffan's correlation for single phase flow and the Martinelli-Nelson's two-phase flow multiplier are found can be well predicted the present pressure drop data under high pressure condition. (author)

  8. The aspects regarding plugging the defective tubes of the steam generator using plastic deformation of the plug wall by conventional or unconventional techniques

    International Nuclear Information System (INIS)

    Gyongyosi, Tiberiu

    2006-01-01

    After a brief introduction the advantages and disadvantages of two plugging methods of the defective tubes from steam generator by plastic deformation of the wall of the plug, deformation performed by mechanical rolling (conventional technique) and by electrohydraulic shock (unconventional technique), respectively, are showed. The paper gives the results of the experimental tests to install the plugs at the end of the tube having the same geometry with those of the steam generator, the performance reached in this stage and some conclusions in the end

  9. A study on the root cause identification of local wall thinning caused by deflected turbulent flow inside orifice of carbon steel components

    International Nuclear Information System (INIS)

    Park, S. H.; Kim, K. H.; Hwang, K. M.

    2010-01-01

    When components made of carbon steel in nuclear, fossil, and industry plants are exposed to flowing fluid, wall thinning caused by FAC (flow accelerated corrosion) can be generated and eventually ruptured at the portion of pressure boundary. A study to identify the locations generating local wall thinning and to disclose turbulence coefficients related to the local wall thinning was performed. Experiments and numerical analyses for orifice of down-scaled piping components were performed and the results were compared. Based on the results that the flow behaviors inside piping components can be simulated by numerical analysis, numerical analyses for magnified models to actual size of plants were performed. To disclose the relationship between turbulence coefficients and local thinning rate, numerical analyses were preformed for orifice components included in the main feedwater systems. The turbulence coefficients based on the numerical analyses were compared with the local wear rate based on the measured data. From the comparison of the results, the vertical flow velocity component (Vr) flowing to the wall after separating in the wall due to the geometrical configuration and colliding with the wall directly at an angle of some degree was analogous to the configuration of local wall thinning. (authors)

  10. Effects of Gas-Wall Partitioning in Teflon Tubing, Instrumentation and Other Materials on Time-Resolved Measurements of Gas-Phase Organic Compounds

    Science.gov (United States)

    Pagonis, D.; Deming, B.; Krechmer, J. E.; De Gouw, J. A.; Jimenez, J. L.; Ziemann, P. J.

    2017-12-01

    Recently it has been shown that gas-phase organic compounds partition to and from the walls of Teflon environmental chambers. This process is fast, reversible, and can be modeled as absorptive partitioning. Here these studies were extended to investigate gas-wall partitioning inside Teflon tubing by introducing step function changes in the concentration of compounds being sampled and measuring the delay in the response of a proton transfer reaction-mass spectrometer (PTR-MS). We find that these delays are significant for compounds with a saturation vapor concentration (c*) below 106 μg m-3, and that the Teflon tubing and the PTR-MS both contribute to the delays. Tubing delays range from minutes to hours under common sampling conditions and can be accurately predicted by a simple chromatography model across a range of tubing lengths and diameters, flow rates, compound functional groups, and c*. This method also allows one to determine the volatility-dependent response function of an instrument, which can be convolved with the output of the tubing model to correct for delays in instrument response time for these "sticky" compounds. This correction is expected to be of particular interest to researchers utilizing and developing chemical ionization mass spectrometry (CIMS) techniques, since many of the multifunctional organic compounds detected by CIMS show significant tubing and instrument delays. These results also enable better design of sampling systems, in particular when fast instrument response is needed, such as for rapid transients, aircraft, or eddy covariance measurements. Additional results presented here extend this method to quantify the relative sorptive capacities for other commonly used tubing materials, including PFA, FEP, PTFE, PEEK, glass, copper, stainless steel, and passivated steel.

  11. Domain wall magnetoresistance in BiFeO3 thin films measured by scanning probe microscopy.

    Science.gov (United States)

    Domingo, N; Farokhipoor, S; Santiso, J; Noheda, B; Catalan, G

    2017-08-23

    We measure the magnetotransport properties of individual 71° domain walls in multiferroic BiFeO 3 by means of conductive-atomic force microscopy (C-AFM) in the presence of magnetic fields up to one Tesla. The results suggest anisotropic magnetoresistance at room temperature, with the sign of the magnetoresistance depending on the relative orientation between the magnetic field and the domain wall plane. A consequence of this finding is that macroscopically averaged magnetoresistance measurements for domain wall bunches are likely to underestimate the magnetoresistance of each individual domain wall.

  12. Arabidopsis wat1 (walls are thin1)-mediated resistance to the bacterial vascular pathogen, Ralstonia solanacearum, is accompanied by cross-regulation of salicylic acid and tryptophan metabolism

    NARCIS (Netherlands)

    Denancé, N.; Ranocha, P.; Oria, N.; Barlet, X.; Rivière, M.P.; Yadeta, K.A.; Hoffmann, L.; Perreau, F.; Clément, G.; Maia-Grondard, A.; Berg, van den G.C.M.; Savelli, B.; Fournier, S.; Aubert, Y.; Pelletier, S.; Thomma, B.P.H.J.; Molina, A.; Jouanin, L.; Marco, Y.; Goffner, D.

    2013-01-01

    Inactivation of Arabidopsis WAT1 (Walls Are Thin1), a gene required for secondary cell-wall deposition, conferred broad-spectrum resistance to vascular pathogens, including the bacteria Ralstonia solanacearum and Xanthomonas campestris pv. campestris, and the fungi Verticillium dahliae and

  13. Magnetic properties, domain-wall creep motion, and the Dzyaloshinskii-Moriya interaction in Pt/Co/Ir thin films

    Science.gov (United States)

    Shepley, Philippa M.; Tunnicliffe, Harry; Shahbazi, Kowsar; Burnell, Gavin; Moore, Thomas A.

    2018-04-01

    We study the magnetic properties of perpendicularly magnetized Pt/Co/Ir thin films and investigate the domain-wall creep method of determining the interfacial Dzyaloshinskii-Moriya (DM) interaction in ultrathin films. Measurements of the Co layer thickness dependence of saturation magnetization, perpendicular magnetic anisotropy, and symmetric and antisymmetric (i.e., DM) exchange energies in Pt/Co/Ir thin films have been made to determine the relationship between these properties. We discuss the measurement of the DM interaction by the expansion of a reverse domain in the domain-wall creep regime. We show how the creep parameters behave as a function of in-plane bias field and discuss the effects of domain-wall roughness on the measurement of the DM interaction by domain expansion. Whereas modifications to the creep law with DM field and in-plane bias fields have taken into account changes in the energy barrier scaling parameter α , we find that both α and the velocity scaling parameter v0 change as a function of in-plane bias field.

  14. Calculation of concrete shielding wall thickness for 450kVp X-ray tube with MCNP simulation and result comparison with half value layer method calculation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Heon; Lee, Eun Joong; Kim, Chan Kyu; Cho, Gyu Seong [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Hur, Sam Suk [Sam Yong Inspection Engineering Co., Ltd., Seoul (Korea, Republic of)

    2016-11-15

    Radiation generating devices must be properly shielded for their safe application. Although institutes such as US National Bureau of Standards and National Council on Radiation Protection and Measurements (NCRP) have provided guidelines for shielding X-ray tube of various purposes, industry people tend to rely on 'Half Value Layer (HVL) method' which requires relatively simple calculation compared to the case of those guidelines. The method is based on the fact that the intensity, dose, and air kerma of narrow beam incident on shielding wall decreases by about half as the beam penetrates the HVL thickness of the wall. One can adjust shielding wall thickness to satisfy outside wall dose or air kerma requirements with this calculation. However, this may not always be the case because 1) The strict definition of HVL deals with only Intensity, 2) The situation is different when the beam is not 'narrow'; the beam quality inside the wall is distorted and related changes on outside wall dose or air kerma such as buildup effect occurs. Therefore, sometimes more careful research should be done in order to verify the effect of shielding specific radiation generating device. High energy X-ray tubes which is operated at the voltage above 400 kV that are used for 'heavy' nondestructive inspection is an example. People have less experience in running and shielding such device than in the case of widely-used low energy X-ray tubes operated at the voltage below 300 kV. In this study, Air Kerma value per week, outside concrete shielding wall of various thickness surrounding 450 kVp X-ray tube were calculated using MCNP simulation with the aid of Geometry Splitting method which is a famous Variance Reduction technique. The comparison between simulated result, HVL method result, and NCRP Report 147 safety goal 0.02 mGy wk-1 on Air Kerma for the place where the public are free to pass showed that concrete wall of thickness 80 cm is needed to achieve the

  15. Calculation of concrete shielding wall thickness for 450kVp X-ray tube with MCNP simulation and result comparison with half value layer method calculation

    International Nuclear Information System (INIS)

    Lee, Sang Heon; Lee, Eun Joong; Kim, Chan Kyu; Cho, Gyu Seong; Hur, Sam Suk

    2016-01-01

    Radiation generating devices must be properly shielded for their safe application. Although institutes such as US National Bureau of Standards and National Council on Radiation Protection and Measurements (NCRP) have provided guidelines for shielding X-ray tube of various purposes, industry people tend to rely on 'Half Value Layer (HVL) method' which requires relatively simple calculation compared to the case of those guidelines. The method is based on the fact that the intensity, dose, and air kerma of narrow beam incident on shielding wall decreases by about half as the beam penetrates the HVL thickness of the wall. One can adjust shielding wall thickness to satisfy outside wall dose or air kerma requirements with this calculation. However, this may not always be the case because 1) The strict definition of HVL deals with only Intensity, 2) The situation is different when the beam is not 'narrow'; the beam quality inside the wall is distorted and related changes on outside wall dose or air kerma such as buildup effect occurs. Therefore, sometimes more careful research should be done in order to verify the effect of shielding specific radiation generating device. High energy X-ray tubes which is operated at the voltage above 400 kV that are used for 'heavy' nondestructive inspection is an example. People have less experience in running and shielding such device than in the case of widely-used low energy X-ray tubes operated at the voltage below 300 kV. In this study, Air Kerma value per week, outside concrete shielding wall of various thickness surrounding 450 kVp X-ray tube were calculated using MCNP simulation with the aid of Geometry Splitting method which is a famous Variance Reduction technique. The comparison between simulated result, HVL method result, and NCRP Report 147 safety goal 0.02 mGy wk-1 on Air Kerma for the place where the public are free to pass showed that concrete wall of thickness 80 cm is needed to achieve the safety goal

  16. Study on the influence of X-ray tube spectral distribution on the analysis of bulk samples and thin films: Fundamental parameters method and theoretical coefficient algorithms

    International Nuclear Information System (INIS)

    Sitko, Rafal

    2008-01-01

    Knowledge of X-ray tube spectral distribution is necessary in theoretical methods of matrix correction, i.e. in both fundamental parameter (FP) methods and theoretical influence coefficient algorithms. Thus, the influence of X-ray tube distribution on the accuracy of the analysis of thin films and bulk samples is presented. The calculations are performed using experimental X-ray tube spectra taken from the literature and theoretical X-ray tube spectra evaluated by three different algorithms proposed by Pella et al. (X-Ray Spectrom. 14 (1985) 125-135), Ebel (X-Ray Spectrom. 28 (1999) 255-266), and Finkelshtein and Pavlova (X-Ray Spectrom. 28 (1999) 27-32). In this study, Fe-Cr-Ni system is selected as an example and the calculations are performed for X-ray tubes commonly applied in X-ray fluorescence analysis (XRF), i.e., Cr, Mo, Rh and W. The influence of X-ray tube spectra on FP analysis is evaluated when quantification is performed using various types of calibration samples. FP analysis of bulk samples is performed using pure-element bulk standards and multielement bulk standards similar to the analyzed material, whereas for FP analysis of thin films, the bulk and thin pure-element standards are used. For the evaluation of the influence of X-ray tube spectra on XRF analysis performed by theoretical influence coefficient methods, two algorithms for bulk samples are selected, i.e. Claisse-Quintin (Can. Spectrosc. 12 (1967) 129-134) and COLA algorithms (G.R. Lachance, Paper Presented at the International Conference on Industrial Inorganic Elemental Analysis, Metz, France, June 3, 1981) and two algorithms (constant and linear coefficients) for thin films recently proposed by Sitko (X-Ray Spectrom. 37 (2008) 265-272)

  17. Analysis of thin-walled cylindrical composite shell structures subject to axial and bending loads: Concept development, analytical modeling and experimental verification

    Science.gov (United States)

    Mahadev, Sthanu

    Continued research and development efforts devoted in recent years have generated novel avenues towards the advancement of efficient and effective, slender laminated fiber-reinforced composite members. Numerous studies have focused on the modeling and response characterization of composite structures with particular relevance to thin-walled cylindrical composite shells. This class of shell configurations is being actively explored to fully determine their mechanical efficacy as primary aerospace structural members. The proposed research is targeted towards formulating a composite shell theory based prognosis methodology that entails an elaborate analysis and investigation of thin-walled cylindrical shell type laminated composite configurations that are highly desirable in increasing number of mechanical and aerospace applications. The prime motivation to adopt this theory arises from its superior ability to generate simple yet viable closed-form analytical solution procedure to numerous geometrically intense, inherent curvature possessing composite structures. This analytical evaluative routine offers to acquire a first-hand insight on the primary mechanical characteristics that essentially govern the behavior of slender composite shells under typical static loading conditions. Current work exposes the robustness of this mathematical framework via demonstrating its potential towards the prediction of structural properties such as axial stiffness and bending stiffness respectively. Longitudinal ply-stress computations are investigated upon deriving the global stiffness matrix model for composite cylindrical tubes with circular cross-sections. Additionally, this work employs a finite element based numerical technique to substantiate the analytical results reported for cylindrically shaped circular composite tubes. Furthermore, this concept development is extended to the study of thin-walled, open cross-sectioned, curved laminated shells that are geometrically

  18. High-speed growth of TiO2 nanotube arrays with gradient pore diameter and ultrathin tube wall under high-field anodization

    Science.gov (United States)

    Yuan, Xiaoliang; Zheng, Maojun; Ma, Li; Shen, Wenzhong

    2010-10-01

    Highly ordered TiO2 nanotubular arrays have been prepared by two-step anodization under high field. The high anodizing current densities lead to a high-speed film growth (0.40-1.00 µm min - 1), which is nearly 16 times faster than traditional fabrication of TiO2 at low field. It was found that an annealing process of Ti foil is an effective approach to get a monodisperse and double-pass TiO2 nanotubular layer with a gradient pore diameter and ultrathin tube wall (nearly 10 nm). A higher anodic voltage and longer anodization time are beneficial to the formation of ultrathin tube walls. This approach is simple and cost-effective in fabricating high-quality ordered TiO2 nanotubular arrays for practical applications.

  19. High-speed growth of TiO{sub 2} nanotube arrays with gradient pore diameter and ultrathin tube wall under high-field anodization

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Xiaoliang; Zheng Maojun; Shen Wenzhong [Key Laboratory of Artificial Structures and Quantum Control, Ministry of Education, Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Ma Li, E-mail: mjzheng@sjtu.edu.cn [School of Chemistry and Chemical Technology, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2010-10-08

    Highly ordered TiO{sub 2} nanotubular arrays have been prepared by two-step anodization under high field. The high anodizing current densities lead to a high-speed film growth (0.40-1.00 {mu}m min{sup -1}), which is nearly 16 times faster than traditional fabrication of TiO{sub 2} at low field. It was found that an annealing process of Ti foil is an effective approach to get a monodisperse and double-pass TiO{sub 2} nanotubular layer with a gradient pore diameter and ultrathin tube wall (nearly 10 nm). A higher anodic voltage and longer anodization time are beneficial to the formation of ultrathin tube walls. This approach is simple and cost-effective in fabricating high-quality ordered TiO{sub 2} nanotubular arrays for practical applications.

  20. A numerical study on the heat transfer in a swirl-tube heated/cooled on the half periphery of the tube wall

    International Nuclear Information System (INIS)

    Aoyama, Yoshiyuki; Kunugi, Tomoaki

    2002-01-01

    Convection heat transfer in a swirl tube was numerically analyzed so as to investigate a characteristic of heat removal when the cooling fluid flows within the swirl tube mounted in a solid structure represented as like a slab. Since the condition of heat inflow was treated as being transmitted only on the one-side surface of the structure, heat conduction through the structure was analyzed in linkage with the convection. Some results for the change in the coefficient of heat transmission along the tube axis are shown. The performance of heat removal was found to be strengthened due to the continuous renovation of thermal boundary layer close to the inside tube surface because the fluid flows in helical motion to shift the range alternate higher and lower temperature. (author)

  1. Fatigue life assessment of thin-walled welded joints under non-proportional load-time histories by the shear stress rate integral approach

    Directory of Open Access Journals (Sweden)

    A. Bolchoun

    2016-10-01

    Full Text Available Fatigue life tests under constant and variable amplitude loadings were performed on the tube-tube thin-walled welded specimens made of magnesium (AZ31 and AZ61 alloys. The tests included pure axial, pure torsional and combined in-phase and out-of-phase loadings with the load ratio  RR " ", " " 1  . For the tests with variable amplitude loads a Gaußdistributed loading spectrum with S L 4 5 10  cycles was used. Since magnesium welds show a fatigue life reduction under out-of-phase loads, a stress-based method, which takes this behavior into account, is proposed. The out-of-phase loading results in rotating shear stress vectors in the section planes, which are not orthogonal to the surface. This fact is used in order to provide an out-of-phase measure of the load. This measure is computed as an area covered by the shear stress vectors in all planes over a certain time interval, its computation involves the shear stress and the shear stress rate vectors in the individual planes. Fatigue life evaluation for the variable amplitudes loadings is performed using the Palmgren-Miner linear damage accumulation, whereas the total damage of every cycle is split up into two components: the amplitude component and the out-of-phase component. In order to compute the two components a modification of the rainflow counting method, which keeps track of the time intervals, where the cycles occur, must be used. The proposed method also takes into account different slopes of the pure axial and the pure torsional Wöhler-line by means of a Wöhler-line interpolation for combined loadings

  2. Self-assembling segmented coiled tubing

    Science.gov (United States)

    Raymond, David W.

    2016-09-27

    Self-assembling segmented coiled tubing is a concept that allows the strength of thick-wall rigid pipe, and the flexibility of thin-wall tubing, to be realized in a single design. The primary use is for a drillstring tubular, but it has potential for other applications requiring transmission of mechanical loads (forces and torques) through an initially coiled tubular. The concept uses a spring-loaded spherical `ball-and-socket` type joint to interconnect two or more short, rigid segments of pipe. Use of an optional snap ring allows the joint to be permanently made, in a `self-assembling` manner.

  3. Effects of gas–wall partitioning in Teflon tubing and instrumentation on time-resolved measurements of gas-phase organic compounds

    Directory of Open Access Journals (Sweden)

    D. Pagonis

    2017-12-01

    Full Text Available Recent studies have demonstrated that organic compounds can partition from the gas phase to the walls in Teflon environmental chambers and that the process can be modeled as absorptive partitioning. Here these studies were extended to investigate gas–wall partitioning of organic compounds in Teflon tubing and inside a proton-transfer-reaction mass spectrometer (PTR-MS used to monitor compound concentrations. Rapid partitioning of C8–C14 2-ketones and C11–C16 1-alkenes was observed for compounds with saturation concentrations (c∗ in the range of 3 × 104 to 1 × 107 µg m−3, causing delays in instrument response to step-function changes in the concentration of compounds being measured. These delays vary proportionally with tubing length and diameter and inversely with flow rate and c∗. The gas–wall partitioning process that occurs in tubing is similar to what occurs in a gas chromatography column, and the measured delay times (analogous to retention times were accurately described using a linear chromatography model where the walls were treated as an equivalent absorbing mass that is consistent with values determined for Teflon environmental chambers. The effect of PTR-MS surfaces on delay times was also quantified and incorporated into the model. The model predicts delays of an hour or more for semivolatile compounds measured under commonly employed conditions. These results and the model can enable better quantitative design of sampling systems, in particular when fast response is needed, such as for rapid transients, aircraft, or eddy covariance measurements. They may also allow estimation of c∗ values for unidentified organic compounds detected by mass spectrometry and could be employed to introduce differences in time series of compounds for use with factor analysis methods. Best practices are suggested for sampling organic compounds through Teflon tubing.

  4. Effects of gas-wall partitioning in Teflon tubing and instrumentation on time-resolved measurements of gas-phase organic compounds

    Science.gov (United States)

    Pagonis, Demetrios; Krechmer, Jordan E.; de Gouw, Joost; Jimenez, Jose L.; Ziemann, Paul J.

    2017-12-01

    Recent studies have demonstrated that organic compounds can partition from the gas phase to the walls in Teflon environmental chambers and that the process can be modeled as absorptive partitioning. Here these studies were extended to investigate gas-wall partitioning of organic compounds in Teflon tubing and inside a proton-transfer-reaction mass spectrometer (PTR-MS) used to monitor compound concentrations. Rapid partitioning of C8-C14 2-ketones and C11-C16 1-alkenes was observed for compounds with saturation concentrations (c∗) in the range of 3 × 104 to 1 × 107 µg m-3, causing delays in instrument response to step-function changes in the concentration of compounds being measured. These delays vary proportionally with tubing length and diameter and inversely with flow rate and c∗. The gas-wall partitioning process that occurs in tubing is similar to what occurs in a gas chromatography column, and the measured delay times (analogous to retention times) were accurately described using a linear chromatography model where the walls were treated as an equivalent absorbing mass that is consistent with values determined for Teflon environmental chambers. The effect of PTR-MS surfaces on delay times was also quantified and incorporated into the model. The model predicts delays of an hour or more for semivolatile compounds measured under commonly employed conditions. These results and the model can enable better quantitative design of sampling systems, in particular when fast response is needed, such as for rapid transients, aircraft, or eddy covariance measurements. They may also allow estimation of c∗ values for unidentified organic compounds detected by mass spectrometry and could be employed to introduce differences in time series of compounds for use with factor analysis methods. Best practices are suggested for sampling organic compounds through Teflon tubing.

  5. Dynamics of explosively imploded pressurized tubes

    Science.gov (United States)

    Szirti, Daniel; Loiseau, Jason; Higgins, Andrew; Tanguay, Vincent

    2011-04-01

    The detonation of an explosive layer surrounding a pressurized thin-walled tube causes the formation of a virtual piston that drives a precursor shock wave ahead of the detonation, generating very high temperatures and pressures in the gas contained within the tube. Such a device can be used as the driver for a high energy density shock tube or hypervelocity gas gun. The dynamics of the precursor shock wave were investigated for different tube sizes and initial fill pressures. Shock velocity and standoff distance were found to decrease with increasing fill pressure, mainly due to radial expansion of the tube. Adding a tamper can reduce this effect, but may increase jetting. A simple analytical model based on acoustic wave interactions was developed to calculate pump tube expansion and the resulting effect on the shock velocity and standoff distance. Results from this model agree quite well with experimental data.

  6. Quantum confinement effect in Bi anti-dot thin films with tailored pore wall widths and thicknesses

    International Nuclear Information System (INIS)

    Park, Y.; Hirose, Y.; Fukumura, T.; Hasegawa, T.; Nakao, S.; Xu, J.

    2014-01-01

    We investigated quantum confinement effects in Bi anti-dot thin films grown on anodized aluminium oxide templates. The pore wall widths (w Bi ) and thickness (t) of the films were tailored to have values longer or shorter than Fermi wavelength of Bi (λ F  = ∼40 nm). Magnetoresistance measurements revealed a well-defined weak antilocalization effect below 10 K. Coherence lengths (L ϕ ) as functions of temperature were derived from the magnetoresistance vs field curves by assuming the Hikami-Larkin-Nagaoka model. The anti-dot thin film with w Bi and t smaller than λ F showed low dimensional electronic behavior at low temperatures where L ϕ (T) exceed w Bi or t

  7. Quantum confinement effect in Bi anti-dot thin films with tailored pore wall widths and thicknesses

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y., E-mail: youngok@chem.s.u-tokyo.ac.jp [Department of Chemistry, The University of Tokyo, Bunkyo, Tokyo 113-0033 (Japan); Hirose, Y.; Fukumura, T.; Hasegawa, T. [Department of Chemistry, The University of Tokyo, Bunkyo, Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan); CREST, JST, Bunkyo, Tokyo 113-0033 (Japan); Nakao, S. [Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan); CREST, JST, Bunkyo, Tokyo 113-0033 (Japan); Xu, J. [School of Engineering, Brown University, Providence, Rhode Island 02912 (United States)

    2014-01-13

    We investigated quantum confinement effects in Bi anti-dot thin films grown on anodized aluminium oxide templates. The pore wall widths (w{sub Bi}) and thickness (t) of the films were tailored to have values longer or shorter than Fermi wavelength of Bi (λ{sub F} = ∼40 nm). Magnetoresistance measurements revealed a well-defined weak antilocalization effect below 10 K. Coherence lengths (L{sub ϕ}) as functions of temperature were derived from the magnetoresistance vs field curves by assuming the Hikami-Larkin-Nagaoka model. The anti-dot thin film with w{sub Bi} and t smaller than λ{sub F} showed low dimensional electronic behavior at low temperatures where L{sub ϕ}(T) exceed w{sub Bi} or t.

  8. Thin films of single-walled carbon nanotubes promote human osteoblastic cells (Saos-2) proliferation in low serum concentrations

    International Nuclear Information System (INIS)

    Akasaka, Tsukasa; Yokoyama, Atsuro; Matsuoka, Makoto; Hashimoto, Takeshi; Watari, Fumio

    2010-01-01

    One strategy used for the regeneration of bone is the development of cell culture substrates and scaffolds that can control osteoblast proliferation and differentiation. In recent investigations, carbon nanotubes (CNTs) have been utilized as scaffolds for osteoblastic cell cultures; however, there are only a few reports describing the proliferation of osteoblastic cells on thin CNT films; in particular, the effects of serum concentration on cell proliferation have not been studied. In the present study, we prepared culture dishes with homogeneous thin or thick films of non-modified CNTs and examined the effect of serum concentrations on human osteoblastic cells (Saos-2) proliferation in these culture dishes. We demonstrated that the ratio of cell proliferation was strongly affected by the concentration of serum. Interestingly, single-walled carbon nanotube (SWNT) thin films were found to be the most effective substrate for the proliferation of Saos-2 cells in low concentrations of serum. Thus, thin SWNT films may be used as an effective biomaterial for the culture of Saos-2 cells in low serum concentrations.

  9. Oxygenation of the traditional and thin-walled MT-YBCO in flowing oxygen and under high evaluated oxygen pressure

    International Nuclear Information System (INIS)

    Prikhna, Tatiana; Chaud, Xavier; Gawalek, Wolfgang; Rabier, Jaques; Savchuk, Yaroslav; Joulain, Anne; Vlasenko, Andrey; Moshchil, Viktor; Sergienko, Nina; Dub, Sergey; Melnikov, Vladimir; Litzkendorf, Doris; Habisreuther, Tobias; Sverdun, Vladimir

    2007-01-01

    The high pressure-high temperature oxygenation of thin-walled MT-YBCO (with artificially produced holes) allows decreasing the amount of macrocracks and increasing j c of the material. The MT-YBCO produced from Y123 and Y211 in the fields higher than 2 T showed higher j c in the ab-planes and lower j c in the c-direction than the MT-YBCO manufactured from Y123 and Y 2 O 3 and can be explained by the difference in twin and microcrack density that in turn can be affected by the difference in Y211 phase distribution

  10. Liquid-metal flow through a thin-walled elbow in a plane perpendicular to a uniform magnetic field

    International Nuclear Information System (INIS)

    Walker, J.S.

    1986-04-01

    This paper presents analytical solutions for the liquid-metal flow through two straight pipes connected by a smooth elbow with the same inside radius. The pipes and the elbow lie in a plane which is perpendicular to a uniform, applied magnetic field. The strength of the magnetic field is assumed to be sufficiently strong that inertial and viscous effects are negligible. This assumption is appropriate for the liquid-lithium flow in the blanket of a magnetic confinement fusion reactor, such as a tokamak. The pipes and the elbow have thin metal walls

  11. Proposal of failure criterion applicable to finite element analysis results for wall-thinned pipes under bending load

    Energy Technology Data Exchange (ETDEWEB)

    Meshii, Toshiyuki, E-mail: meshii@u-fukui.ac.jp [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui (Japan); Ito, Yoshiaki [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui (Japan)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Limit bending load (LBL) of wall-thinned pipe by large strain FEA was considered. Black-Right-Pointing-Pointer Net section yield load had sufficient margin to LBL. Black-Right-Pointing-Pointer LBL for collapse was the load when volume with nominal thickness yielded. Black-Right-Pointing-Pointer LBL for cracking was the load when flawed section stress exceeded tensile strength. Black-Right-Pointing-Pointer Failure criterion considering above was named Domain Collapse Criterion. - Abstract: In this work, a failure criterion applicable to large strain Finite Element Analysis (FEA) results was proposed in order to predict both the fracture mode (collapse or cracking) and the limit bending load of wall-thinned straight pipes. This work was motivated from the recent experimental results of ; that is, fracture mode is not always collapse, and the fracture mode affects the limit bending load. The key finding in comparing their test results and a detailed large strain FEA results was that the Mises stress distribution at the limit bending load of a flawed cylinder was similar to that of a flawless cylinder; specifically, in case of collapse, the Mises stress exceeded the true yield stress of a material for the whole 'volume' of a cylinder with a nominal wall thickness. Based on this finding, a failure criterion applicable to large strain FEA results of wall-thinned straight pipes under a bending load that can predict both fracture mode and limit bending load was proposed and was named the Domain Collapse Criterion (DCC). DCC predicts the limit bending load as the lower value of either the M{sub c}{sup FEA}, which is the load at which the Mises stress exceeds the true yield strength of a straight pipe for the whole 'volume' with a nominal wall thickness (fracture mode: collapse), or the M{sub c}{sup FEAb}, which is the load at which the Mises stress in a section of the flaw ligament exceeds the true tensile stress

  12. A study on the shell wall thinning causes identified through experiment, numerical analysis and ultrasonic test of high-pressure feedwater heater

    International Nuclear Information System (INIS)

    Hwang, Kyeong Mo; Woo, Lee; Jin, Tae Eun; Kim, Kyung Hoon

    2008-01-01

    Feedwater heaters of many nuclear power plants have recently experienced severe wall thinning damage, which accelerates as the operation progresses. Several nuclear power plants in Korea have undergone this damage around the impingement baffle - installed downstream of the high-pressure turbine extraction steam line - inside numbers 5A and 5B feedwater heaters. At that point, the extracted steam from the high-pressure turbine consists in the form of two-phase fluid at high temperature, high pressure and high velocity. Since it flows in reverse direction after impinging the impingement baffle, the shell wall of number 5 high-pressure feedwater heater may be affected by flow-accelerated corrosion. This paper describes the comparisons between the numerical analysis results using the FLUENT code and the downscaled experimental data in an effort to determine root causes of the shell wall thinning of the high-pressure feedwater heaters. The numerical analysis and experimental data were also confirmed by the actual wall thickness measured by ultrasonic tests. From the comparison of the results for the local velocity profiles and the wall thinning measurements, the local velocity component only in the y-direction flowing vertically to the shell wall, and not in the x- and z-directions, was analogous to the wall thinning data

  13. Contribution to the understanding of the high magnetic field compression produced by the implosion of a thin metal tube

    International Nuclear Information System (INIS)

    Besancon, Jacques

    1970-12-01

    In this report we present the essential phenomena which occur during the magnetic flux compression obtained by the explosive-driven implosion of a thin conducting liner: acceleration time, dynamic evolution, heating and instability behaviour of the liner; field diffusion through the conducting wall and resulting flux losses which condition the increasing field in the cavity. Various implosion models are proposed and the one most elaborated leads to a numerical computation of the flux compression. Repeated experiments have permitted us to define and improve the flux injection techniques, the optical and electrical diagnostics and, consequently, the final compressed field. We now know how to obtain and record reproducible fields of 12 MOe in 0.8 cm diameter cavities. The final phase or the liner 'turnaround' has been specially observed. All the implosion shots are compared to the theoretical expectation. It may be concluded that the liner electrical conductivity and its variation essentially determine the final flux value. (author) [fr

  14. Numerical analysis for the optimal location of a thin PCM layer in frame walls

    International Nuclear Information System (INIS)

    Jin, Xing; Medina, Mario A.; Zhang, Xiaosong

    2016-01-01

    Highlights: • The optimal PCM location was estimated by a mathematical model. • The optimal PCM location was affected by the properties of PCM. • The optimal PCM location was affected by the environmental conditions. - Abstract: The thermal performance of building walls can be improved using phase change materials (PCMs). The objective of this study was to estimate the optimal location of a “thin” PCM layer to be incorporated into frame walls, parallel to the frame and insulation, for the purpose of increasing thermal mass and reducing peak heat fluxes through the wall. Based on a mathematical model built in this paper, it was found that an optimal location of this “thin” PCM layer can be estimated, and it was affected by the thermal properties of PCM and the environmental conditions. The optimal locations for the PCM layer were found to be closer to the exterior surface of the wall when the thickness of PCM layer, the heat of fusion of PCM, and the PCM melting temperature were increased, while the optimal location was closer to the interior surface of the wall when the interior surface temperature of the wall was increased.

  15. NUMERICAL ANALYSIS OF THE CRITICAL STATE OF THIN-WALLED STRUCTURE WITH Z-PROFILE CROSS SECTION

    Directory of Open Access Journals (Sweden)

    Patryk Różyło

    2017-03-01

    Full Text Available The object of the study was the thin-walled profile with Z-shaped cross section made of the carbon-epoxy composite. Material model was prepared based on the implemented orthotropic properties. The purpose of study was to determine the value of the critical load at which buckling occurs, the form of buckling and operating characteristics in critical condition. In order to achieve this numerical analysis were carried out. Additionally, the effects of the modification in arrangement of layers of the laminate to the stability and strength of thin-walled composite structures was presented. Numerical studies were carried out using commercial simulation software - ABAQUS®. Within the FEM research, both forms of buckling and the associated critical load, dependent on the configuration the layers of the composite were achieved. Analysis of the obtained results, allowed the evaluation of the structure's work in relation to the level of energy consumption or rigidity estimation. In the paper only numerical simulations of the critical state were conducted.

  16. Vibration characteristics of two-stage planetary transmission system with thin-walled ring gear on elastic supports

    Science.gov (United States)

    Li, JianYing; Hu, QingChun; Zong, ChangFu; Zhu, TianJun; Zhang, ZeXing

    2018-03-01

    A dual-clutch and dual-speed planetary gears mechanism of a hybrid car coupled-system is taken as research subject, in which the ring gear of planet set II is a thin-walled structure and the clutch friction plates of planet set II are used as its elastic supports. Based on the lumped parameter-rigid elastic coupled dynamic model of two-stage planetary transmission system with thin-walled ring gear on elastic supports, the motion differential equations are established and the dynamic responses are solved by the Runge-Kutta method considering each stage internal and external time-varying mesh stiffness. The vibration displacements of each stage ring gear have been affected differently in time-domain, the translational vibration displacement of the ring gear of planet set I are obviously more than the torsional vibration displacement, but it is opposite for the ring gear of planet set II; The translational and torsional vibration responses of each stage ring gear arrive the peak in low-frequency. The analysis results of this paper can enrich the theoretical research of multistage planetary transmission and provide guidance for dynamic design.

  17. Numerical modelling of thin-walled Z-columns made of general laminates subjected to uniform shortening

    Science.gov (United States)

    Teter, Andrzej; Kolakowski, Zbigniew

    2018-01-01

    The numerical modelling of a plate structure was performed with the finite element method and a one-mode approach based on Koiter's method. The first order approximation of Koiter's method enables one to solve the eigenvalue problem. The second order approximation describes post-buckling equilibrium paths. In the finite element analysis, the Lanczos method was used to solve the linear problem of buckling. Simulations of the non-linear problem were performed with the Newton-Raphson method. Detailed calculations were carried out for a short Z-column made of general laminates. Configurations of laminated layers were non-symmetric. Due to possibilities of its application, the general laminate is very interesting. The length of the samples was chosen to obtain the lowest value of local buckling load. The amplitude of initial imperfections was 10% of the wall thickness. Thin-walled structures were simply supported on both ends. The numerical results were verified in experimental tests. A strain-gauge technique was applied. A static compression test was performed on a universal testing machine and a special grip, which consisted of two rigid steel plates and clamping sleeves, was used. Specimens were obtained with an autoclave technique. Tests were performed at a constant velocity of the cross-bar equal to 2 mm/min. The compressive load was less than 150% of the bifurcation load. Additionally, soft and thin pads were used to reduce inaccuracy of the sample ends.

  18. Defect detection of wall thinning defect in pipes using lock-in photo-infrared thermography technique

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Su Ok; Park, Jong Hyun; Choi, Tae Ho; Jung, Hyun Chul; Kim, Kyoung Suk [Chosun Univ., Gwangju (Korea, Republic of)

    2008-07-01

    Piping in the Nuclear Power plants (NPP) are mostly consisted of carbon steel pipe. The wall thinning defect is mainly occurred by the affect of the Flow Accelerated Corrosion (FAC) of fluid which flows in carbon steel pipes. This type of defect becomes the cause of damage or destruction of piping. Therefore, it is very important to measure defect which is existed not only on the welding partbut also on the whole field of pipe. Over the years, Infrared Thermography (IRT) has been used as a non destructive testing methods of the various kinds of materials. This technique has many merits and applied to the industrial field but has limitation to the materials. Therefore, this method was combined with lock-in technique. So IRT detection resolution has been progressively improved using lock-in technique. In this paper, the quantitative analysis results of the location and the size of wall thinning defect that is artificially processed inside the carbon steel pipe by using IRT are obtained.

  19. Influence of substrate material on the microstructure and optical properties of hot wall deposited SnS thin films

    International Nuclear Information System (INIS)

    Bashkirov, S.A.; Gremenok, V.F.; Ivanov, V.A.; Shevtsova, V.V.; Gladyshev, P.P.

    2015-01-01

    Tin monosulfide SnS raises an interest as a promising material for photovoltaics. The influence of the substrate material on the microstructure and optical properties of SnS thin films with [111] texture obtained by hot wall vacuum deposition on glass, molybdenum and indium tin oxide substrates is reported. The lattice parameters for layers grown on different substrates were determined by X-ray diffraction and their deviations from the data reported in the literature for single α-SnS crystals were discussed. The change in the degree of preferred orientation of the films depending on the substrate material is observed. The direct nature of the optical transitions with the optical band gap of 1.15 ± 0.01 eV is reported. - Highlights: • SnS thin films were hot wall deposited on glass, molybdenum and indium tin oxide. • Physical properties of the films were studied with respect to the substrate type. • The SnS lattice parameter deviations were observed and the explanation was given. • The direct optical transitions with the band gap of 1.15 ± 0.01 eV were observed

  20. Substrate clamping effects on irreversible domain wall dynamics in lead zirconate titanate thin films.

    Science.gov (United States)

    Griggio, F; Jesse, S; Kumar, A; Ovchinnikov, O; Kim, H; Jackson, T N; Damjanovic, D; Kalinin, S V; Trolier-McKinstry, S

    2012-04-13

    The role of long-range strain interactions on domain wall dynamics is explored through macroscopic and local measurements of nonlinear behavior in mechanically clamped and released polycrystalline lead zirconate-titanate (PZT) films. Released films show a dramatic change in the global dielectric nonlinearity and its frequency dependence as a function of mechanical clamping. Furthermore, we observe a transition from strong clustering of the nonlinear response for the clamped case to almost uniform nonlinearity for the released film. This behavior is ascribed to increased mobility of domain walls. These results suggest the dominant role of collective strain interactions mediated by the local and global mechanical boundary conditions on the domain wall dynamics. The work presented in this Letter demonstrates that measurements on clamped films may considerably underestimate the piezoelectric coefficients and coupling constants of released structures used in microelectromechanical systems, energy harvesting systems, and microrobots.

  1. Selective Deposition and Alignment of Single-Walled Carbon Nanotubes Assisted by Dielectrophoresis: From Thin Films to Individual Nanotubes

    Science.gov (United States)

    Li, Pengfei; Xue, Wei

    2010-06-01

    Dielectrophoresis has been used in the controlled deposition of single-walled carbon nanotubes (SWNTs) with the focus on the alignment of nanotube thin films and their applications in the last decade. In this paper, we extend the research from the selective deposition of SWNT thin films to the alignment of small nanotube bundles and individual nanotubes. Electrodes with “teeth”-like patterns are fabricated to study the influence of the electrode width on the deposition and alignment of SWNTs. The entire fabrication process is compatible with optical lithography-based techniques. Therefore, the fabrication cost is low, and the resulting devices are inexpensive. A series of SWNT solutions is prepared with concentrations ranging from 0.0125 to 0.2 mg/ml. The alignment of SWNT thin films, small bundles, and individual nanotubes is achieved under the optimized experimental conditions. The electrical properties of these samples are characterized; the linear current-voltage plots prove that the aligned SWNTs are mainly metallic nanotubes. The microscopy inspection of the samples demonstrates that the alignment of small nanotube bundles and individual nanotubes can only be achieved using narrow electrodes and low-concentration solutions. Our investigation shows that it is possible to deposit a controlled amount of SWNTs in desirable locations using dielectrophoresis.

  2. Development of Wall Thinning Distinction Method using the Multi-inspecting UT Data of Carbon Steel Piping

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kyeong Mo; Yun, Hun; Lee, Chan Kyoo [KEPCO E and C, Yongin (Korea, Republic of)

    2012-05-15

    To manage the wall thinning of carbon steel piping in nuclear power plants, the utility of Korea has performed thickness inspection for some quantity of pipe components during refueling outages and determined whether repair or replacement after evaluating UT (Ultrasonic Test) data. When the existing UT data evaluation methods, such as Band, Blanket, PTP (Point to Point) Methods, are applied to a certain pipe component, unnecessary re-inspecting situations may be generated even though the component does not thinned. In those cases, economical loss caused by repeated inspection and problems of maintaining the pipe integrity followed by decreasing of newly inspected components may be generated. EPRI (Electric Power Research Institute) in USA has suggested several statistical methods, TPM (Total Point Method), LSS (Least Square Slope) Method, etc. to distinguish whether multiple inspecting components have thinned or not. This paper presents the analysis results for multiple inspecting components over three times based on both NAM (Near Area of Minimum) Method developed by KEPCO-E and C and the other methods suggested by EPRI.

  3. Selective Deposition and Alignment of Single-Walled Carbon Nanotubes Assisted by Dielectrophoresis: From Thin Films to Individual Nanotubes

    Directory of Open Access Journals (Sweden)

    Li Pengfei

    2010-01-01

    Full Text Available Abstract Dielectrophoresis has been used in the controlled deposition of single-walled carbon nanotubes (SWNTs with the focus on the alignment of nanotube thin films and their applications in the last decade. In this paper, we extend the research from the selective deposition of SWNT thin films to the alignment of small nanotube bundles and individual nanotubes. Electrodes with “teeth”-like patterns are fabricated to study the influence of the electrode width on the deposition and alignment of SWNTs. The entire fabrication process is compatible with optical lithography-based techniques. Therefore, the fabrication cost is low, and the resulting devices are inexpensive. A series of SWNT solutions is prepared with concentrations ranging from 0.0125 to 0.2 mg/ml. The alignment of SWNT thin films, small bundles, and individual nanotubes is achieved under the optimized experimental conditions. The electrical properties of these samples are characterized; the linear current–voltage plots prove that the aligned SWNTs are mainly metallic nanotubes. The microscopy inspection of the samples demonstrates that the alignment of small nanotube bundles and individual nanotubes can only be achieved using narrow electrodes and low-concentration solutions. Our investigation shows that it is possible to deposit a controlled amount of SWNTs in desirable locations using dielectrophoresis.

  4. Tissue factor levels and the fibrinolytic system in thin and thick intraluminal thrombus and underlying walls of abdominal aortic aneurysms.

    Science.gov (United States)

    Siennicka, Aldona; Zuchowski, Marta; Kaczmarczyk, Mariusz; Cnotliwy, Miłosław; Clark, Jeremy Simon; Jastrzębska, Maria

    2018-03-20

    The hemostatic system cooperates with proteolytic degradation in processes allowing abdominal aortic aneurysm (AAA) formation. In previous studies, it has been suggested that aneurysm rupture depends on intraluminal thrombus (ILT) thickness, which varies across each individual aneurysm. We hypothesized that hemostatic components differentially accumulate in AAA tissue in relation to ILT thickness. Thick (A1) and thin (B1) segments of ILTs and aneurysm wall sections A (adjacent to A1) and B (adjacent to B1) from one aneurysm sac were taken from 35 patients undergoing elective repair. Factor levels were measured using enzyme-linked immunosorbent assay of protein extract. Tissue factor (TF) activities were significantly higher in thinner segments of AAA (B1 vs A1, P = .003; B vs A, P thick thrombus-covered wall segments (A) than in B, A1, and B1 (P = .015, P thick ILT (P = .021) and thick ILT (A1; P thick ILT (A1). However, no correlations were found at B sites, except for a correlation between plasmin and TF activities (r = 0.55; P = .004). These results suggest that higher TF activities are present in thinner AAA regions. These parameters and local fibrinolysis may be part of the processes leading to destruction of the aneurysm wall. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  5. Thin and flexible all-solid supercapacitor prepared from novel single wall carbon nanotubes/polyaniline thin films obtained in liquid-liquid interfaces

    Science.gov (United States)

    de Souza, Victor Hugo Rodrigues; Oliveira, Marcela Mohallem; Zarbin, Aldo José Gorgatti

    2014-08-01

    The present work describes for the first time the synthesis and characterization of single wall carbon nanotubes/polyaniline (SWNTs/PAni) nanocomposite thin films in a liquid-liquid interface, as well as the subsequent construction of a flexible all-solid supercapacitor. Different SWNTs/PAni nanocomposites were prepared by varying the ratio of SWNT to aniline, and the samples were characterized by scanning and transmission electron microscopy, Raman and UV-Vis spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The pseudo-capacitive behavior of the nanocomposites was evaluated by charge/discharge galvanostatic measurements. The presence of the SWNTs affected the electronic and vibrational properties of the polyaniline and also improved the pseudo-capacitive behavior of the conducting polymer. A very thin and flexible all-solid device was manufactured using two electrodes (polyethylene terephthalate-PET covered with the SWNT/PAni nanocomposite separated by a H2SO4-PVA gel electrolyte). The pseudo-capacitive behavior was characterized by a volumetric specific capacitance of approximately 76.7 F cm-3, even under mechanical deformation, indicating that this nanocomposite has considerable potential for application in new-generation energy storage devices.

  6. Domain wall magnetoresistance in BiFeO3 thin films measured by scanning probe microscopy

    NARCIS (Netherlands)

    Domingo, N.; Farokhipoor, S.; Santiso, J.; Noheda, B.; Catalan, G.

    2017-01-01

    We measure the magnetotransport properties of individual 71 degrees domain walls in multiferroic BiFeO3 by means of conductive-atomic force microscopy (C-AFM) in the presence of magnetic fields up to one Tesla. The results suggest anisotropic magnetoresistance at room temperature, with the sign of

  7. 75 FR 33779 - Light-Walled Rectangular Pipe and Tube from Turkey; Notice of Preliminary Results of Antidumping...

    Science.gov (United States)

    2010-06-15

    ..., Inc. and Searing Industries, Inc. are petitioners in this case. The review covers exports of the..., Atlas Tube, Inc. and Searing Industries, Inc. (``Petitioners'') made an entry of appearance in this...

  8. AC dielectrophoresis alignment of single-walled carbon nano tubes (SWNTS) and palladium nano wires for hydrogen gas sensor

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Nur Ubaidah Saidin; Ying, K.K.; KKhuan, N.I.; Mohammad Hafizuddin Jumali

    2013-01-01

    Full-text: Using AC electric field, nano wires or nano tubes can be aligned, chained or accelerated in a direction parallel to the applied field, oriented or concentrated onto designated locations as well as dispersed in controlled manner under high efficiencies. In this work, systematic study on the alignment of nano wires/ nano tubes across the 3 μm-gaps between pairs of micro fabricated gold electrodes was carried out using AC dielectrophoresis technique. Densities and alignment of the nano wires/ nano tubes across the gaps of the electrodes were controlled by the applied AC field strengths and frequencies on the electrodes. Good alignments of SWNTs and Pd nano wires were achieved at an applied frequency of 5 MHz and a field strength as high as 25 V pp for Pd nano wires compared to only 2 V pp for SWNTs. The aligned nano wires/ nano tubes will be functioned as sensor elements for hydrogen gas sensing. (author)

  9. Measurement of pipe wall thinning by ultra acoustic resonance technique using optical fiber

    International Nuclear Information System (INIS)

    Shirai, Takehiro; Machijima, Yuichi

    2009-01-01

    This is the novel system for Pipe Wall Thickness measurement which is combined EAMT(Electro Magnetic Acoustic Transducer) and Optical Fiber Sensor. The conventional ultrasonic thickness meter is using in pipe wall thickness measurement. However, it is necessary to remove a heat insulator from pipe line. A characteristic of this novel system is that it is possible to measure without removing a heat insulator and on-line monitoring, because of measurement probe is attached between pipe surface and heat insulator. As a result of measured with this system, we could measure 30 mm thickness of carbon and stainless steel at the maximum and pipe specimen of elbow shape. Heat-resistant characteristic confirmed at 200 degrees C until about 7000 hours. (author)

  10. Grain Boundaries Act as Solid Walls for Charge Carrier Diffusion in Large Crystal MAPI Thin Films.

    Science.gov (United States)

    Ciesielski, Richard; Schäfer, Frank; Hartmann, Nicolai F; Giesbrecht, Nadja; Bein, Thomas; Docampo, Pablo; Hartschuh, Achim

    2018-03-07

    Micro- and nanocrystalline methylammonium lead iodide (MAPI)-based thin-film solar cells today reach power conversion efficiencies of over 20%. We investigate the impact of grain boundaries on charge carrier transport in large crystal MAPI thin films using time-resolved photoluminescence (PL) microscopy and numerical model calculations. Crystal sizes in the range of several tens of micrometers allow for the spatially and time resolved study of boundary effects. Whereas long-ranged diffusive charge carrier transport is observed within single crystals, no detectable diffusive transport occurs across grain boundaries. The observed PL transients are found to crucially depend on the microscopic geometry of the crystal and the point of observation. In particular, spatially restricted diffusion of charge carriers leads to slower PL decay near crystal edges as compared to the crystal center. In contrast to many reports in the literature, our experimental results show no quenching or additional loss channels due to grain boundaries for the studied material, which thus do not negatively affect the performance of the derived thin-film devices.

  11. Analysis of a multi pass weld of a thick walled tube made of austenitic stainless steel X6 CrNiNb 18 10

    International Nuclear Information System (INIS)

    Scholtes, B.; Zinn, W.; Ilg, U.; Backfisch, W.; Gibmeier, J.; Kirch, D.

    2006-01-01

    In this paper, microstructure and residual stresses of a multi pass welding of a thick-walled tube made of austenitic stainless steel X6 CrNiNb 18 10 (1.4550) are systematically characterized and assessed. Results of microstructural and phase analyses, residual stress and hardness measurements as well as of a tensile test using micro specimen and SEM analyses are presented. Using these data, plastic deformations occurring during the welding process in the vicinity of the weld seam are evaluated. Finally, consequences of an additional heat treatment at 400 C/24 h are studied. (Abstract Copyright [2006], Wiley Periodicals, Inc.) [de

  12. Application of several plasticity models to the analysis of a tube subjected to traction and combined torsion

    International Nuclear Information System (INIS)

    Caumette, Pierre; Cheissoux, J.L.

    1982-01-01

    The progressive deformation of a thin-walled steel tube is analysed when the tube is submitted to cyclic torsion under constant loading. Isotopic and kinematic hardening models are applied, assuming a bilinear stress-strain law (constant hardening modulus) [fr

  13. Process for producing molybdenum foil and collapsible tubing

    Science.gov (United States)

    Bretts, G. R.; Gavert, R. B.; Groschke, G. F.

    1971-01-01

    Manufacturing process produces molybdenum foil 0.002 cm thick and 305 m long, and forms foil into high-strength, thin-walled tubing which can be flattened for storage on a spool. Desirable metal properties include high thermal conductivity stiffness, yield and tensile stress, and low thermal expansion coeffecient.

  14. On Love's approximation for fluid-filled elastic tubes

    International Nuclear Information System (INIS)

    Caroli, E.; Mainardi, F.

    1980-01-01

    A simple procedure is set up to introduce Love's approximation for wave propagation in thin-walled fluid-filled elastic tubes. The dispersion relation for linear waves and the radial profile for fluid pressure are determined in this approximation. It is shown that the Love approximation is valid in the low-frequency regime. (author)

  15. A system of two piezoelectric transducers and a storage circuit for wireless energy transmission through a thin metal wall.

    Science.gov (United States)

    Hu, Hongping; Hu, Yuantai; Chen, Chuanyao; Wang, Ji

    2008-10-01

    A system to wirelessly convey electric energy through a thin metal wall is proposed in the paper, where 2 piezoelectric transducers are used to realize energy transformation between electric and mechanical, and a rechargeable battery is employed to store the transmitted energy. To integrate them as a whole, an interface of a modulating circuit is applied between the transducer system and the storage battery. In addition, a synchronized switch harvesting on inductor in parallel with the transducer system is introduced to artificially extend the closed interval of the modulating circuit. The process of transmitting energy is computed, and the performance of the transducer system is optimized in detail for a prescribed external electric source. The results obtained are useful for understanding and designing wireless energy supply systems.

  16. Material and structural mechanical modelling and reliability of thin-walled bellows at cryogenic temperatures. Application to LHC compensation system

    CERN Document Server

    Garion, Cédric; Skoczen, Blazej

    The present thesis is dedicated to the behaviour of austenitic stainless steels at cryogenic temperatures. The plastic strain induced martensitic transformation and ductile damage are taken into account in an elastic-plastic material modelling. The kinetic law of →’ transformation and the evolution laws of kinematic/isotropic mixed hardening are established. Damage issue is analysed by different ways: mesoscopic isotropic or orthotropic model and a microscopic approach. The material parameters are measured from 316L fine gauge sheet at three levels of temperature: 293 K, 77 K and 4.2 K. The model is applied to thin-walled corrugated shell, used in the LHC interconnections. The influence of the material properties on the stability is studied by a modal analysis. The reliability of the components, defined by the Weibull distribution law, is analysed from fatigue tests. The impact on reliability of geometrical imperfections and thermo-mechanical loads is also analysed.

  17. Multifractal characterization of single wall carbon nanotube thin films surface upon exposure to optical parametric oscillator laser irradiation

    International Nuclear Information System (INIS)

    Ţălu, Ştefan; Marković, Zoran; Stach, Sebastian; Todorović Marković, B.; Ţălu, Mihai

    2014-01-01

    This study presents a multifractal approach, obtained with atomic force microscopy analysis, to characterize the structural evolution of single wall carbon nanotube thin films upon exposure to optical parametric oscillator laser irradiation at wavelength of 430 nm. Microstructure and morphological changes of carbon nanotube films deposited on different substrates (mica and TGX grating) were recorded by atomic force microscope. A detailed methodology for surface multifractal characterization, which may be applied for atomic force microscopy data, was presented. Multifractal analysis of surface roughness revealed that carbon nanotube films surface has a multifractal geometry at various magnifications. The generalized dimension D q and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of carbon nanotube films surface morphology at nanometer scale. Multifractal analysis provides different yet complementary information to that offered by traditional surface statistical parameters.

  18. Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes/polymer composite thin film.

    Science.gov (United States)

    Rajanna, Pramod Mulbagal; Gilshteyn, Evgenia; Yagafarov, Timur; Alekseeva, Alena; Anisimov, Anton; Sergeev, Oleg; Neumueller, Alex; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert

    2018-01-09

    We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and a thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high quality SWCNTs with an enhanced conductivity by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with different SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit Jsc, open-circuit Voc, and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and efficiency of 3.4% under simulated one-sun AM 1.5G direct illumination. © 2018 IOP Publishing Ltd.

  19. Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes and polymer composite thin film

    Science.gov (United States)

    Rajanna, Pramod M.; Gilshteyn, Evgenia P.; Yagafarov, Timur; Aleekseeva, Alena K.; Anisimov, Anton S.; Neumüller, Alex; Sergeev, Oleg; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert G.

    2018-03-01

    We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high-quality SWCNTs with conductivity enhanced by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with varying SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit J sc , open-circuit V oc , and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and an efficiency of 3.4% under simulated one-sun AM 1.5 G direct illumination.

  20. Oxygenation of the traditional and thin-walled MT-YBCO in flowing oxygen and under high evaluated oxygen pressure

    Energy Technology Data Exchange (ETDEWEB)

    Prikhna, Tatiana [Institute for Superhard Materials, 2 Avtozavodskaya Street, Kiev 04074 (Ukraine)], E-mail: prikhna@iptelecom.net.ua; Chaud, Xavier [CNRS/CRETA, 25, Avenue des Martyrs BP 166, 38042 Grenoble, Cedex 9 (France); Gawalek, Wolfgang [Institut fuer Physikalische Hochtechnologie, Albert-Einstein-Strasse 9, Jena (Germany); Rabier, Jaques [Universite de Poitiers, CNRS/Lab. de Metallurgie Physique, UMR 6630 CNRS-Universite de Poitiers SP2MI, BP 30179, F-86962 Chasseneuil Futuroscope Cedex (France); Savchuk, Yaroslav [Institute for Superhard Materials, 2 Avtozavodskaya Street, Kiev 04074 (Ukraine); Joulain, Anne [Universite de Poitiers, CNRS/Lab. de Metallurgie Physique, UMR 6630 CNRS-Universite de Poitiers SP2MI, BP 30179, F-86962 Chasseneuil Futuroscope Cedex (France); Vlasenko, Andrey; Moshchil, Viktor; Sergienko, Nina; Dub, Sergey; Melnikov, Vladimir [Institute for Superhard Materials, 2 Avtozavodskaya Street, Kiev 04074 (Ukraine); Litzkendorf, Doris; Habisreuther, Tobias [Institut fuer Physikalische Hochtechnologie, Albert-Einstein-Strasse 9, Jena (Germany); Sverdun, Vladimir [Institute for Superhard Materials, 2 Avtozavodskaya Street, Kiev 04074 (Ukraine)

    2007-09-01

    The high pressure-high temperature oxygenation of thin-walled MT-YBCO (with artificially produced holes) allows decreasing the amount of macrocracks and increasing j{sub c} of the material. The MT-YBCO produced from Y123 and Y211 in the fields higher than 2 T showed higher j{sub c} in the ab-planes and lower j{sub c} in the c-direction than the MT-YBCO manufactured from Y123 and Y{sub 2}O{sub 3} and can be explained by the difference in twin and microcrack density that in turn can be affected by the difference in Y211 phase distribution.

  1. STUDY OF STATIC AND DYNAMIC STABILITY OF THIN-WALLED BARS EXCITED BY PERIODICAL AXIAL EXTERNAL FORCES.

    Directory of Open Access Journals (Sweden)

    Minodora Maria PASĂRE

    2010-10-01

    Full Text Available In these paper, starting from the relations for the displacements and spinning the transversal section of a bar with thin walls of sections opened expressed by the corresponding influence functions and introducing the components of the exterior forces distributed and the moments of the exterior forces distributed due to the inertia forces, the exciting axial forces together with the following effect of these and of the reaction forces of the elastic environment for leaning it may reach to the system of the equations of parametric vibrations under the form of three integral equation These equations may serve for the study of vibrations of the bars, to study the static stability and to study the dynamic stability

  2. Finite element analysis of the design and manufacture of thin-walled pressure vessels used as aerosol cans

    Science.gov (United States)

    Abdussalam, Ragba Mohamed

    Thin-walled cylinders are used extensively in the food packaging and cosmetics industries. The cost of material is a major contributor to the overall cost and so improvements in design and manufacturing processes are always being sought. Shape optimisation provides one method for such improvements. Aluminium aerosol cans are a particular form of thin-walled cylinder with a complex shape consisting of truncated cone top, parallel cylindrical section and inverted dome base. They are manufactured in one piece by a reverse-extrusion process, which produces a vessel with a variable thickness from 0.31 mm in the cylinder up to 1.31 mm in the base for a 53 mm diameter can. During manufacture, packaging and charging, they are subjected to pressure, axial and radial loads and design calculations are generally outside the British and American pressure vessel codes. 'Design-by-test' appears to be the favoured approach. However, a more rigorous approach is needed in order to optimise the designs. Finite element analysis (FEA) is a powerful tool for predicting stress, strain and displacement behaviour of components and structures. FEA is also used extensively to model manufacturing processes. In this study, elastic and elastic-plastic FEA has been used to develop a thorough understanding of the mechanisms of yielding, 'dome reversal' (an inherent safety feature, where the base suffers elastic-plastic buckling at a pressure below the burst pressure) and collapse due to internal pressure loading and how these are affected by geometry. It has also been used to study the buckling behaviour under compressive axial loading. Furthermore, numerical simulations of the extrusion process (in order to investigate the effects of tool geometry, friction coefficient and boundary conditions) have been undertaken. Experimental verification of the buckling and collapse behaviours has also been carried out and there is reasonable agreement between the experimental data and the numerical

  3. 'Thin walled' concept and a new top lid applied to the Scandinavian PCRV for a boiling water reactor

    International Nuclear Information System (INIS)

    Scotto, F.L.

    1975-01-01

    This research is carried out in the frame of an agreement between AB ATOMENERGI of Sweden and ENEL (Ente Nazionale per l'Energia Elettrica) of Italy, for an exchange of information in the field of PCPV for BWR, and takes as a reference the Scandinavian solution as far as the thermal insulation system and the geometry are concerned, proposing new solutions for the prestressed concrete structure (namely the Author's concept of thin walls and a new concept of top lid). The proposed top lid sealing system solution is in line with the one adopted for the conventional steel pressure vessel enclosures; furthermore the prestressed concrete lid is restricted to the prestressed concrete structure to form a continuous contrete structure, in line with th PCPV conventional solutions for gas reactors. The paper describes in detail the selected design philosophy that is slightly different from the one defined by the Scandinavian project. In fact, as far as the design limits are concerned, it refers mainly to steel pressure vessel philosophy and, as to the concrete behaviour, to the design philosophy proposed by the author for the PCPV 'thin walled' structures for gas-cooled power reactors. Rheological, mathematical and physical models had been suitably devised in order to check the reliability of the proposed assumption. This paper therefore, will also give a brief description of said tools and the main results acquired at the time of the conference, and technical and economical considerations made to support the interest of the research, showing the relevant cut down of the costs. The comparative reference steel pressure vessel belongs to Mark III ENEL VI and VIII BW plant to which design and construction the author gives his contribution

  4. Structural and leakage integrity assessment of WWER steam generator tubes

    International Nuclear Information System (INIS)

    Splichal, K.; Otruba, J.; Keilova, E.; Krhounek, V.; Turek, J.

    1996-01-01

    The leakage and plugging limits were derived for WWER steam generators based on leak and burst tests using tubes with axial part-through and through-wall defects. The following conclusions were arrived at: (i) The permissible primary-to-secondary leak rate with respect to the permissible through-wall defect size of WWER-440 and WWER-1000 steam generator tubes is 8 l/h. (ii) The primary-to-secondary leak rate is reduced by the blocking of the tube cracks by corrosion product particles and other substances. (iii) The rate of crack penetration through the tube wall is higher than the crack widening. (iv) The validity of the criterion of instability for tubes with through-wall cracks was confirmed experimentally. For the WWER-440 and WWER-1000 steam generators, the critical size of axial through-wall cracks, for the threshold primary-to-secondary pressure difference, is 13.8 and 12.0 mm, respectively. (v) The calculated leakage for the rupture of one tube and for the assumed extreme defects is two orders and one order of magnitude, respectively, higher than the proposed primary water leakage limit of 8 l/h. (vi) The experiments gave evidence that the use of the permissible thinning limit of 80% for the heat exchange tube plugging does not bring about uncontrollable leakage or unstable crack growth. This is consistent with experience gained at WWER-440 type nuclear power plants. 4 tabs., 5 figs., 9 refs

  5. Effect of injection parameters on mechanical and physical properties of super ultra-thin wall propylene packaging by Taguchi method

    Science.gov (United States)

    Ginghtong, Thatchanok; Nakpathomkun, Natthapon; Pechyen, Chiravoot

    2018-06-01

    The parameters of the plastic injection molding process have been investigated for the manufacture of a 64 oz. ultra-thin polypropylene bucket. The 3 main parameters, such as injection speed, melting temperature, holding pressure, were investigated to study their effect on the physical appearance and compressive strength. The orthogonal array of Taguchi's L9 (33) was used to carry out the experimental plan. The physical properties were measured and the compressive strength was determined using linear regression analysis. The differential scanning calorimeter (DSC) was used to analyze the crystalline structure of the product. The optimization results show that the proposed approach can help engineers identify optimal process parameters and achieve competitive advantages of energy consumption and product quality. In addition, the injection molding of the product includes 24 mm of shot stroke, 1.47 mm position transfer, 268 rpm screw speed, injection speed 100 mm/s, 172 ton clamping force, 800 kgf holding pressure, 0.9 s holding time and 1.4 s cooling time, make the products in the shape and proportion of the product satisfactory. The parameters of influence are injection speed 71.07%, melting temperature 23.31% and holding pressure 5.62%, respectively. The compressive strength of the product was able to withstand a pressure of up to 839 N before the product became plastic. The low melting temperature was caused by the superior crystalline structure of the super-ultra-thin wall product which leads to a lower compressive strength.

  6. Inkjet printing of aligned single-walled carbon-nanotube thin films

    Science.gov (United States)

    Takagi, Yuki; Nobusa, Yuki; Gocho, Shota; Kudou, Hikaru; Yanagi, Kazuhiro; Kataura, Hiromichi; Takenobu, Taishi

    2013-04-01

    We report a method for the inkjet printing of aligned single-walled carbon-nanotube (SWCNT) films by combining inkjet technology with the strong wettability contrast between hydrophobic and hydrophilic areas based on the patterning of self-assembled monolayers. Both the drying process control using the strong wettability boundary and the coffee-stain effect strongly promote the aggregation of SWCNTs along the contact line of a SWCNT ink droplet, thereby demonstrating our achievement of inkjet-printed aligned SWCNT films. This method could open routes for developing high-performance and environmentally friendly SWCNT printed electronics.

  7. Thermoelectric Cooling-Aided Bead Geometry Regulation in Wire and Arc-Based Additive Manufacturing of Thin-Walled Structures

    Directory of Open Access Journals (Sweden)

    Fang Li

    2018-01-01

    Full Text Available Wire and arc-based additive manufacturing (WAAM is a rapidly developing technology which employs a welding arc to melt metal wire for additive manufacturing purposes. During WAAM of thin-walled structures, as the wall height increases, the heat dissipation to the substrate is slowed down gradually and so is the solidification of the molten pool, leading to variation of the bead geometry. Though gradually reducing the heat input via adjusting the process parameters can alleviate this issue, as suggested by previous studies, it relies on experience to a large extent and inevitably sacrifices the deposition rate because the wire feed rate is directly coupled with the heat input. This study introduces for the first time an in-process active cooling system based on thermoelectric cooling technology into WAAM, which aims to eliminate the difference in heat dissipation between upper and lower layers. The case study shows that, with the aid of thermoelectric cooling, the bead width error is reduced by 56.8%, the total fabrication time is reduced by 60.9%, and the average grain size is refined by 25%. The proposed technique provides new insight into bead geometry regulation during WAAM with various benefits in terms of geometric accuracy, productivity, and microstructure.

  8. Resistive wall instabilities and tearing mode dynamics in the EXTRAP T2R thin shell reversed-field pinch

    Science.gov (United States)

    Malmberg, J.-A.; Brunsell, P. R.

    2002-01-01

    Observations of resistive wall instabilities and tearing mode dynamics in the EXTRAP T2R thin shell (τw=6 ms) reversed field pinch are described. A nonresonant mode (m=1,n=-10) with the same handedness as the internal field grows nearly exponentially with an average growth time of about 2.6 ms (less than 1/2 of the shell time) consistent with linear stability theory. The externally nonresonant unstable modes (m=1,n>0), predicted by linear stability theory, are observed to have only low amplitudes (in the normal low-Θ operation mode of the device). The radial field of the dominant internally resonant tearing modes (m=1,n=-15 to n=-12) remain low due to spontaneous fast mode rotation, corresponding to angular phase velocities up to 280 krad/s. Phase aligned mode structures are observed to rotate toroidally with an average angular velocity of 40 krad/s, in the opposite direction of the plasma current. Toward the end of the discharge, the radial field of the internally resonant modes grows as the modes slow down and become wall-locked, in agreement with nonlinear computations. Fast rotation of the internally resonant modes has been observed only recently and is attributed to a change of the front-end system (vacuum vessel, shell, and TF coil) of the device.

  9. Self-sustaining thin films as a means of reducing first wall erosion and plasma impurity influx

    International Nuclear Information System (INIS)

    Krauss, A.R.; Gruen, D.M.

    1982-01-01

    Neutral impurities ejected from Tokamak wall and limiter surfaces may travel several cm before being ionized very quickly upon entering the plasma edge. The influence of the unipolar sheath potential is exerted only within a very short distance of the surface and has no effect on neutral impurity atoms within a very short distance of the surface and has no effect on neutral impurity atoms which are subsequently ionized by charge-exchange collisions or electron impact ionization. However, secondary ions emanating from the limiter surfaces with kinetic energies less than the sheath potential will have essentially zero probability of traveling more than a few Debye lengths before being redeposited. Similarly, secondary ions originating at the first wall are redeposited as a result of the deflection produced by the magnetic field. Impurity influx resulting from sputtering would therefore be substantially reduced for surfaces which produce a very high ion/neutral ratio when sputtered. It has been previously shown that the high secondary ion yield associated with the alkali metal potassium does not apply to the bulk metal but pertains to ionic compounds and thin (mono-layer) films. Two processes are discussed as a means of producing these films in a self-sustaining manner compatible with the fusion reactor environment. (orig.)

  10. Thin-film electroencephalographic electrodes using multi-walled carbon nanotubes are effective for neurosurgery.

    Science.gov (United States)

    Awara, Kousuke; Kitai, Ryuhei; Isozaki, Makoto; Neishi, Hiroyuki; Kikuta, Kenichiro; Fushisato, Naoki; Kawamoto, Akira

    2014-12-15

    Intraoperative morphological and functional monitoring is essential for safe neurosurgery. Functional monitoring is based on electroencephalography (EEG), which uses silver electrodes. However, these electrodes generate metal artifacts as silver blocks X-rays, creating white radial lines on computed tomography (CT) images during surgery. Thick electrodes interfere with surgical procedures. Thus, thinner and lighter electrodes are ideal for intraoperative use. The authors developed thin brain electrodes using carbon nanotubes that were formed into thin sheets and connected to electrical wires. The nanotube sheets were soft and fitted the curve of the head very well. When attached to the head using paste, the impedance of the newly developed electrodes was 5 kΩ or lower, which was similar to that of conventional metal electrodes. These electrodes can be used in combination with intraoperative CT, magnetic resonance imaging (MRI), or cerebral angiography. Somatosensory-evoked potentials, auditory brainstem responses, and visually evoked potentials were clearly identified in ten volunteers. The electrodes, without any artifacts that distort images, did not interfere with X-rays, CT, or MR images. They also did not cause skin damage. Carbon nanotube electrodes may be ideal for neurosurgery.

  11. Application of Response Surface Methodology for Optimization of Urea Grafted Multi walled Carbon Nano tubes in Enhancing Nitrogen Use Efficiency and Nitrogen Uptake by Paddy Plants

    International Nuclear Information System (INIS)

    Yatim, N. M.; Shaaban, A.; Dimin, M. F.; Yusof, F.; Abo Razak, J.

    2016-01-01

    Efficient use of urea fertilizer (UF) as important nitrogen (N) source in the world’s rice production has been a concern. Carbon-based materials developed to improve UF performance still represent a great challenge to be formulated for plant nutrition. Advanced N nano carrier is developed based on functionalized multi wall carbon nano tubes (f-MWCNTs) grafted with UF to produce urea-multi wall carbon nano tubes (UF-MWCNTs) for enhancing the nitrogen uptake (NU) and use efficiency (NUE). The grafted N can be absorbed and utilized by rice efficiently to overcome the N loss from soil-plant systems. The individual and interaction effect between the specified factors of f-MWCNTs amount (0.10-0.60 wt%) and functionalization reflux time (12-24 hrs) with the corresponding responses (NUE, NU) were structured via the Response Surface Methodology (RSM) based on five-level CCD. The UF-MWCNTs with optimized 0.5 wt% f-MWCNTs treated at 21 hrs reflux time achieve tremendous NUE up to 96% and NU at 1180 mg/pot. Significant model terms (Þ value < 0.05) for NUE and NU responses were confirmed by the ANOVA. Homogeneous dispersion of UF-MWCNTs was observed via FESEM and TEM. The chemical changes were monitored by FT-IR and Raman spectroscopy. Hence, this UF-MWCNTs’ approach provides a promising strategy in enhancing plant nutrition for rice.

  12. A proposal on restart rule of nuclear power plants with piping having local wall thinning subjected to an earthquake. Former part. Aiming at further application

    International Nuclear Information System (INIS)

    Urabe, Yoshio

    2011-01-01

    Restart rule of nuclear power plants (NPPs) with piping having local wall thinning subjected to an earthquake was proposed taking account of local wall thinning, seismic effects and restart of NPPs with applicability of 'Guidelines for NPP Response to an Earthquake (EPRI NP-6695)' in Japan. Japan Earthquake Damage Intensity Scale (JEDIS) and Earthquake Ground Motion Level (EGML) were introduced. JEDIS was classified into four scales obtained from damage level of components and structures of NPPs subjected to an earthquake, while EGML was divided into four levels by safe shutdown earthquake ground motion (So), elastic design earthquake ground motion (Sd) and design earthquake ground motion (Ss). Combination of JEDIS and EGML formulated 4 x 4 matrix and determined detailed conditions of restart of NPPs. As a response to an earthquake, operator walk inspections and evaluation of earthquake ground motion were conducted to know the level of JEDIS. JEDIS level requested respective allowable conditions of restart of NPP, which were scale level dependent and consisted of weighted combination of damage inspection (operator walk inspections, focused inspections/tests and expanded inspections), integrity evaluation and repair/replacement. If JEDIS were assigned greater than 3 with expanded inspections, inspection of piping with local wall thinning, its integrity evaluation and repair/replacement if necessary were requested. Inspection and evaluation of piping with local wall thinning was performed based on JSME or ASME codes. Detailed work flow charts were presented. Carbon steel piping and elbow was chosen for evaluation. (T. Tanaka)

  13. Flux mapping at 77 K and local measurement at lower temperature of thin-wall YBaCuO single-domain samples oxygenated under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Chaud, X., E-mail: Xavier.chaud@grenoble.cnrs.f [CRETA, CNRS, 25, Avenue des Martyrs, 38042 Grenoble Cedex 9 (France); Noudem, J. [CRISMAT/ENSICAEN, CNRS, 6 bd Marechal Juin, 14050 Caen (France); Prikhna, T.; Savchuk, Y. [ISM, National Acad. of Sciences of Ukraine, 2 Avtozavodskaya Street, Kiev, 04074 (Ukraine); Haanappel, E. [LNCMP, UMR 5147, 143 avenue de Rangueil, 31400 Toulouse (France); Diko, P. [IEP, Slovak Acad. of Sciences, Watsonova 47, 043 53, Kosice (Slovakia); Zhang, C.P. [SMRC, NIN, 96 Weiyang Road, Xi' an 710016 (China)

    2009-10-15

    YBCO single-domain samples are suitable for the production of high trapped fields in the range 20-77 K using a cryocooler or liquid nitrogen. But the oxygenation process required to actually transform the single domains into superconductors induces an extensive crack network that is limiting the material performances. Thin-wall geometry has been introduced to reduce the diffusion paths and to enable a progressive oxygenation strategy. As a consequence cracks are drastically reduced. In addition the use of a high oxygen pressure (16 MPa) speeds up further the process by displacing the oxygen-temperature equilibrium towards the higher temperature of the phase diagram. The advantage of thin-wall geometry is that such an annealing can be applied directly to a much larger sample. Remarkable results are obtained without any doping by the combination of thin walls and oxygen high pressure. While classical plain samples yield 300-400 mT, a trapped field of 840 mT has been measured at 77 K on a 16 mm diameter Y123 thin-wall single-domain sample with an annealing time as short as 3 days. Local measurements with a fixed Hall probe on top of the sample were performed at lower temperature after magnetization either in a static field or in a pulse field. The trapped field is significantly higher at lower temperature. Cryocoolers become the key to compromise between performances and cryogenic cost around 40 K.

  14. Electronmicroscopical evaluation of short-term nerve regeneration through a thin-walled biodegradable poly(DLLA-epsilon-CL) nerve guide filled with modified denatured muscle tissue

    NARCIS (Netherlands)

    Meek, MF; Robinson, PH; Stokroos, [No Value; Blaauw, EH; Kors, G; den Dunnen, WFA

    The aim of this study was to evaluate short-term peripheral nerve regeneration across a 15-mm gap in the sciatic nerve of the rat, using a thin-walled biodegradable poly(DL-lactide-epsilon -caprolactone) nerve guide filled with modified denatured muscle tissue (MDMT). The evaluation was performed

  15. Analysis of Cavity Pressure and Warpage of Polyoxymethylene Thin Walled Injection Molded Parts: Experiments and Simulations

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Tosello, Guido; Hattel, Jesper Henri

    2014-01-01

    Process analysis and simulations on molding experiments of 3D thin shell parts have been conducted. Moldings were carried out with polyoxymethylene (POM). The moldings were performed with cavity pressure sensors in order to compare experimental process results with simulations. The warpage...... was characterized by measuring distances using a tactile coordinate measuring machine (CMM). Molding simulations have been executed taking into account actual processing conditions. Various aspects have been considered in the simulation: machine barrel geometry, injection speed profiles, cavity injection pressure......, melt and mold temperatures, material rheological and pvT characterization. Factors investigated for comparisons were: injection pressure profile, short shots length, flow pattern, and warpage. A reliable molding experimental database was obtained, accurate simulations were conducted and a number...

  16. Fabrication of thin-wall, freestanding inertial confinement fusion targets by chemical vapor deposition

    International Nuclear Information System (INIS)

    Carroll, D.W.; McCreary, W.J.

    1982-01-01

    To meet the requirements for plasma physics experiments in the inertial confinement fusion (ICF) program, chemical vapor deposition (CVD) in fluid beds was used to fabricate freestanding tungsten spheres and cylinders with wall thicknesses less than 5.0 μm. Molybdenum and molybdenum alloy (TZM) mandrels of the desired geometry were suspended in a carrier bed of dense microspheres contained in an induction-heated fluid-bed reactor. The mandrels were free to float randomly through the bed, and using the reaction WF 6 +3H 2 →/sub /KW +6HF, very fine-grained tungsten was deposited onto the surface at a rate and in a grain size determined by temperature, gas flow rate, system pressure, and duration of the reaction. After coating, a portion of each mandrel was exposed by hole drilling or grinding. The mandrel was then removed by acid leaching, leaving a freestanding tungsten shape. Experimental procedures, mandrel preparation, and results obtained are discussed

  17. Influence of a boatlanding and j-tubes on wave loads and wall thickness of the monopile support structure design

    NARCIS (Netherlands)

    Segeren, M.L.A.

    2011-01-01

    Support structures for offshore wind turbines play a significant part in the cost of offshore wind energy. With current access systems a conventional boat landing is not necessary. Secondary steel, such as a boat landing and J-tube, influences wave loads. A way of taking the secondary steel items

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

    DEFF Research Database (Denmark)

    2014-01-01

    The sealing device (1) includes an elongated body (5) adapted to be introduced into a tube-shaped channel (2) and including a sealing fluid placement section (6) arranged between a first and a second annular flow barrier (7, 8). The elongated body further includes a sealing fluid activation secti...

  19. Low mass MEMS/NEMS switch for a substitute of CMOS transistor using single-walled carbon nanotube thin film

    Science.gov (United States)

    Jang, Min-Woo

    Power dissipation is a key factor for mobile devices and other low power applications. Complementary metal oxide semiconductor (CMOS) is the dominant integrated circuit (IC) technology responsible for a large part of this power dissipation. As the minimum feature size of CMOS devices enters into the sub 50 nanometer (nm) regime, power dissipation becomes much worse due to intrinsic physical limits. Many approaches have been studied to reduce power dissipation of deeply scaled CMOS ICs. One possible candidate is the electrostatic electromechanical switch, which could be fabricated with conventional CMOS processing techniques. They have critical advantages compared to CMOS devices such as almost zero standby leakage in the off-state due to the absence of a pn junction and a gate oxide, as well as excellent drive current in the on-state due to a metallic channel. Despite their excellent standby power dissipation, the electrostatic MEMS/NEMS switches have not been considered as a viable replacement for CMOS devices due to their large mechanical delay. Moreover, previous literature reveals that their pull-in voltage and switching speed are strongly proportional to each other. This reduces their potential advantage. However, in this work, we theoretically and experimentally demonstrated that the use of single-walled carbon nanotube (SWNT) with very low mass density and strong mechanical properties could provide a route to move off of the conventional trend with respect to the pull-in voltage / switching speed tradeoff observed in the literature. We fabricated 2-terminal fixed- beam switches with aligned composite SWNT thin films. In this work, layer-by-layer (LbL) self-assembly and dielectrophoresis were selected for aligned-composite SWNT thin film deposition. The dense membranes were successfully patterned to form submicron beams by e-beam lithography and oxygen plasma etching. Fixed-fixed beam switches using these membranes successfully operated with approximately 600

  20. Operating properties of straw-tube

    International Nuclear Information System (INIS)

    Alekseev, G.D.; Bonyushkin, Yu.E.; Korytov, A.V.; Malyshev, V.L.

    1990-01-01

    The initial results of the study of thin-wall mylar tubes (called straws) made under the laboratory conditions are presented. The maximal avalanche charge allowing the reliable detector operation is ∼ 10 pC, the spatial accuracy σ x near the anode wire at 3 atm of pure isobutane is ≅ 45 μm. The good separation of charge signals from electrons and X-rays was obtained with the Xe:iso-C 4 H 10 = 94:6 gas mixture. Tubes 5 mm in diameter withstand the pressure of 8-12 atm. 11 refs.; 5 figs

  1. Power spectral estimation of high-harmonics in echoes of wall resonances to improve resolution in non-invasive measurements of wall mechanical properties in rubber tube and ex-vivo artery.

    Science.gov (United States)

    Bazan, I; Ramos, A; Balay, G; Negreira, C

    2018-07-01

    The aim of this work is to develop a new type of ultrasonic analysis of the mechanical properties of an arterial wall with improved resolution, and to confirm its feasibility under laboratory conditions. it is expected that this would facilitate a non-invasive path for accurate predictive diagnosis that enables an early detection & therapy of vascular pathologies. In particular, the objective is to detect and quantify the small elasticity changes (in Young's modulus E) of arterial walls, which precede pathology. A submicron axial resolution is required for this analysis, as the periodic widening of the wall (under oscillatory arterial pressure) varies between ±10 and 20 μm. This high resolution represents less than 1% of the parietal thickness (e.g., harmonics of the wall internal resonance f 0 . This was attained via the implementation of an autoregressive parametric algorithm that accurately detects parietal echo-dynamics during a heartbeat. Thus, it was possible to measure the punctual elasticity of the wall, with a higher resolution (> an order of magnitude) compared to conventional approaches. The resolution of a typical ultrasonic image is limited to several hundred microns, and thus, such small changes are undetected. The proposed procedure provides a non-invasive and direct measure of elasticity by doing an estimation of changes in the Nf 0 harmonics and wall thickness with a resolution of 0.1%, for first time. The results obtained by using the classic temporal cross-correlation method (TCC) were compared to those obtained with the new procedure. The latter allowed the evaluation of alterations in the elastic properties of arterial walls that are 30 times smaller than those being detectable with TCC; in fact, the depth resolution of the TCC approach is limited to ≈20 μm for typical SNRs. These values were calculated based on echoes obtained using a reference pattern (rubber tube). The application of the proposed procedure was also confirmed via

  2. Correcting and coating thin walled X-ray Optics via a combination of controlled film deposition and magnetic smart materials

    Science.gov (United States)

    Ulmer, Melville

    The project goal is to demonstrate that thin walled (price. Since the desired surface area for the next generation X-ray telescope is >10x that of Chandra, the >10x requirement is then for >200 m^2 of surface area with a surface finish of better than 0.5 nm. Therefore, replication of some sort is called for. Because no replication technology has been shown to achieve ≤1" angular resolution, post fabrication figure corrections are likely going to be necessary. Some have proposed to do this in orbit and others prelaunch including us. Our prelaunch approach is to apply in-plane stresses to the thin walled mirror shells via a magnetic field. The field will be held in by some magnetically hard material such as NiCo. By use of a so called magnetic smart material (MSM) such as Terfenol-D, we already shown that strong enough stresses can be generated. Preliminary work has also shown that the magnetic field can be held in well enough to apply the figure correcting stresses pre-launch. What we call "set-it and forget-it." However, what is unique about our approach is that at the cost of complexity and some areal coverage, our concept will also accommodate in-orbit adjustments. Furthermore, to the best of our knowledge ours is one of two known stress modification processes that are bi-axial. Our plan is first to validate set-it and forget-it first on cantilevers and then to expand this to working on 5 cm x 5 cm pieces. We will work both with NiCo and glass or Si coated with Terfenol-D. Except for the NiCo, substrates we will also coat the samples with NiCo in order to have a film that will hold in the magnetic field. As part of the coating process, we will control the stress of the film by varying the voltage bias while coating. The bias stress control can be used to apply films with minimal stress such as Terfenol-D and X-ray reflecting coatings such as Ir. Ir is a highly desirable coating for soft X-ray astronomy mirrors that can have significant built in stress unless

  3. MODELING OF KINEMATICS OF A PLASTIC SHAPING AT CALIBRATION OF A THIN-WALLED PRECISION PIPE SINKING

    Directory of Open Access Journals (Sweden)

    E. D. Chertov

    2014-01-01

    Full Text Available Summary. The mathematical model of kinematics of a plastic shaping at the sinking of a thin-walled precision pipe applied to calibration of the ends of the unified elements of the pipeline of aircraft from titanic alloys and corrosion-resistant steel before assembly to the route by means of automatic argon-arc welding of ring joints is developed. For modeling, the power criterion of stability with use of kinematic possible fields of speeds is applied to receiving the top assessment of effort of deformation. The developed model of kinematics of a plastic current allows to receive power parameters of the main condition of process of calibration by sinking and can be used for the solution of a task on stability of process of deformation by results of comparison of power (power parameters for the main (steady and indignant states. Modeling is made in cylindrical system of coordinates by comparison of options of kinematic possible fields of the speeds of a current meeting a condition of incompressibility and kinematic regional conditions. The result of the modeling was selected discontinuous field of high-speed, in which the decrease outer radius (R occurs only by increasing the thickness of the pipe wall (t. For this option the size of pressure of sinking had the smallest value, therefore the chosen field of speeds closely to the valid. It is established that with increase in a step of giving 1 at calibration by the multisector tool the demanded pressure of sinking of q decreases. At an identical step of giving 1 pipe with the smaller relative thickness of (t/r needs to be calibrated the smaller pressure of sinking. With increase of a limit of fluidity at shift of material of pipe preparation pressure of sinking of (q increases.

  4. Characterisation of a complex thin walled structure fabricated by selective laser melting using a ferritic oxide dispersion strengthened steel

    Energy Technology Data Exchange (ETDEWEB)

    Boegelein, Thomas, E-mail: t.boegelein@liv.ac.uk; Louvis, Eleftherios; Dawson, Karl; Tatlock, Gordon J.; Jones, Andy R.

    2016-02-15

    Oxide dispersion strengthened (ODS) alloys exhibit superior mechanical and physical properties due to the presence of nanoscopic Y(Al, Ti) oxide precipitates, but their manufacturing process is complex. The present study is aimed at further investigation of the application of an alternative, Additive Manufacturing (AM) technique, Selective Laser Melting (SLM), to the production of consolidated ODS alloy components. Mechanically alloyed PM2000 (ODS-FeCrAl) powders have been consolidated and a fine dispersion of Y-containing precipitates were observed in an as built thin-walled component, but these particles were typically poly-crystalline and contained a variety of elements including O, Al, Ti, Cr and Fe. Application of post-build heat treatments resulted in the modification of particle structures and compositions; in the annealed condition most precipitates were transformed to single crystal yttrium aluminium oxides. During the annealing treatment, precipitate distributions homogenised and localised variations in number density were diminished. The resulting volume fractions of those precipitates were 25–40% lower than have been reported in conventionally processed PM2000, which was attributed to Y-rich slag-like surface features and inclusions formed during SLM. - Highlights: • A wall structure was grown from ODS steel powder using selective laser melting. • A fine dispersion of nano-precipitates was apparent in as-build material. • Precipitates were multi-phased containing several elements, e.g. O, Ti, Al, Fe, Cr, Y. • Post-build annealing changed those into typically single-crystalline Y–Al–O. • The anneal also reduced and stabilised the volume fraction of precipitates to ~ 0.006.

  5. STRAIN CONCENTRATION IN APICES OF RADIAL CRACKS IN A THIN COATED PIPE WALL

    Directory of Open Access Journals (Sweden)

    M. M. Payzulaev

    2017-01-01

    Full Text Available Objectives. The well-known discontinuous solution method, used in the study of infinite and semi-infinite domains, is generalised during the construction of solutions in Fourier series. This makes it possible to reduce the problem of the mechanics of a deformable solid for a limited region containing cuts or inclusions to the solution of an integral equation (or system with respect to discontinuities of the functions being defined.Methods. The method was implemented through the application to the solution of the theoretical elasticity problem for a pipe section (plane deformation weakened by an internal radial crack. The pipe was loaded with hydrostatic pressure and a thin coating is applied on its inner surface, improving its physical and mechanical properties. The applied method, combined with the conventional integral transformation, can be effectively used in the construction of discontinuous solutions of three-dimensional problems of the theory of elasticity.Results. Specially formulated boundary conditions were used as a coating model. In order to verify the adequacy of the adopted model, a series of numerical experiments was carried out. In some cases, calculations were carried out for the cross-section of a coated pipe in finite-element ANSYS and COMSOL software packages. In others, benefiting from the extensive capabilities of the FlexPDE software package, an uncoated pipe model was constructed, although using special boundary conditions. Comparison of the results obtained made it possible to ascertain the adequacy of the models constructed across a certain range of geometric and physical parameters.Conclusion. The problem is reduced to the solution of a singular integral equation with a Cauchy kernel with respect to the derivative of the jump in the tangential component of the displacement vector on the crack edges. Its solution is determined by the collocation method with a pre-selected feature. The ultimate goal of the study is to

  6. Modeling of thin-walled structures interacting with acoustic media as constrained two-dimensional continua

    Science.gov (United States)

    Rabinskiy, L. N.; Zhavoronok, S. I.

    2018-04-01

    The transient interaction of acoustic media and elastic shells is considered on the basis of the transition function approach. The three-dimensional hyperbolic initial boundary-value problem is reduced to a two-dimensional problem of shell theory with integral operators approximating the acoustic medium effect on the shell dynamics. The kernels of these integral operators are determined by the elementary solution of the problem of acoustic waves diffraction at a rigid obstacle with the same boundary shape as the wetted shell surface. The closed-form elementary solution for arbitrary convex obstacles can be obtained at the initial interaction stages on the background of the so-called “thin layer hypothesis”. Thus, the shell–wave interaction model defined by integro-differential dynamic equations with analytically determined kernels of integral operators becomes hence two-dimensional but nonlocal in time. On the other hand, the initial interaction stage results in localized dynamic loadings and consequently in complex strain and stress states that require higher-order shell theories. Here the modified theory of I.N.Vekua–A.A.Amosov-type is formulated in terms of analytical continuum dynamics. The shell model is constructed on a two-dimensional manifold within a set of field variables, Lagrangian density, and constraint equations following from the boundary conditions “shifted” from the shell faces to its base surface. Such an approach allows one to construct consistent low-order shell models within a unified formal hierarchy. The equations of the N th-order shell theory are singularly perturbed and contain second-order partial derivatives with respect to time and surface coordinates whereas the numerical integration of systems of first-order equations is more efficient. Such systems can be obtained as Hamilton–de Donder–Weyl-type equations for the Lagrangian dynamical system. The Hamiltonian formulation of the elementary N th-order shell theory is

  7. Structural and leakage integrity assessment of WWER steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Splichal, K.; Otruba, J. [Nuclear Research Inst., Rez (Switzerland)

    1997-12-31

    The integrity of heat exchange tubes may influence the life-time of WWER steam generators and appears to be an important criterion for the evaluation of their safety and operational reliability. The basic requirement is to assure a very low probability of radioactive water leakage, preventing unstable crack growth and sudden tube rupture. These requirements led to development of permissible limits for primary to secondary leak evolution and heat exchange tubes plugging based on eddy current test inspection. The stress corrosion cracking and pitting are the main corrosion damage of WWER heat exchange tubes and are initiated from the outer surface. They are influenced by water chemistry, temperature and tube wall stress level. They take place under crevice corrosion condition and are indicated especially (1) under the tube support plates, where up to 90-95 % of defects detected by the ECT method occur, and (2) on free spans under tube deposit layers. Both the initiation and crack growth cause thinning of the tube wall and lead to part thickness cracks and through-wall cracks, oriented above all in the axial direction. 10 refs.

  8. Structural and leakage integrity assessment of WWER steam generator tubes

    International Nuclear Information System (INIS)

    Splichal, K.; Otruba, J.

    1997-01-01

    The integrity of heat exchange tubes may influence the life-time of WWER steam generators and appears to be an important criterion for the evaluation of their safety and operational reliability. The basic requirement is to assure a very low probability of radioactive water leakage, preventing unstable crack growth and sudden tube rupture. These requirements led to development of permissible limits for primary to secondary leak evolution and heat exchange tubes plugging based on eddy current test inspection. The stress corrosion cracking and pitting are the main corrosion damage of WWER heat exchange tubes and are initiated from the outer surface. They are influenced by water chemistry, temperature and tube wall stress level. They take place under crevice corrosion condition and are indicated especially (1) under the tube support plates, where up to 90-95 % of defects detected by the ECT method occur, and (2) on free spans under tube deposit layers. Both the initiation and crack growth cause thinning of the tube wall and lead to part thickness cracks and through-wall cracks, oriented above all in the axial direction

  9. Structural and leakage integrity assessment of WWER steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Splichal, K; Otruba, J [Nuclear Research Inst., Rez (Switzerland)

    1998-12-31

    The integrity of heat exchange tubes may influence the life-time of WWER steam generators and appears to be an important criterion for the evaluation of their safety and operational reliability. The basic requirement is to assure a very low probability of radioactive water leakage, preventing unstable crack growth and sudden tube rupture. These requirements led to development of permissible limits for primary to secondary leak evolution and heat exchange tubes plugging based on eddy current test inspection. The stress corrosion cracking and pitting are the main corrosion damage of WWER heat exchange tubes and are initiated from the outer surface. They are influenced by water chemistry, temperature and tube wall stress level. They take place under crevice corrosion condition and are indicated especially (1) under the tube support plates, where up to 90-95 % of defects detected by the ECT method occur, and (2) on free spans under tube deposit layers. Both the initiation and crack growth cause thinning of the tube wall and lead to part thickness cracks and through-wall cracks, oriented above all in the axial direction. 10 refs.

  10. WWER steam generator tube structural and leakage integrity

    International Nuclear Information System (INIS)

    Splichal, K.; Krhounek, Vl.; Otruba, J.; Ruscak, M.

    1998-01-01

    The integrity of heat exchange tubes may influence the lifetime of WWER steam generators and appears to be an important criterion for the evaluation of their safety and operational reliability. The basic requirements are to assure very low probability of radioactive water leakage, preventing unstable crack growth and sudden tube rupture. These requirements led to development of permissible limits for primary to secondary leak evaluation and heat exchange tubes plugging. The stress corrosion cracking and pitting are the main corrosion damages of WWER heat exchange tubes and are initiated from the outer surface. Both the initiation and crack growth cause thinning of the tube wall and lead to part thickness cracks and through wall cracks, oriented preferentially in the axial direction. The paper presents the leakage and plugging limits for WWER steam generators, which have been determined from leak tests and burst tests. The tubes with axial part-through and through-wall defects have been used. The permissible value of primary to secondary leak rate was evaluated with respect to permissible axial through-wall defect size of WWER 440 and 1000 steam generator tubes. Blocking of the tube cracks by corrosion product particles and other compounds reduces the primary to secondary leak rate. The plugging limits involve the following factors: permissible tube wall thickness which determine further operation of the tubes with defects and assures their integrity under operating conditions and permissible size of a through-wall crack which is sufficiently stable under normal and accident conditions in relation to the critical crack length. For the evaluation of burst test of heat exchange tubes with longitudinal through-wall defects the instability criterion has been used and the dependence of the normalised burst pressure on the normalised length of an axial through-wall defect has been determined. The validity of the criterion of instability for WWER tubes with through-wall

  11. Estimates of the burst reliability of thin-walled cylinders designed to meet the ASME Code allowables

    International Nuclear Information System (INIS)

    Stancampiano, P.A.; Zemanick, P.P.

    1976-01-01

    Pressure containment components in nuclear power plants are designed by the conventional deterministic safety factor approach to meet the requirements of the ASME Pressure Vessel Code, Section III. The inevitable variabilities and uncertainties associated with the design, manufacture, installation, and service processes suggest a probabilistic design approach may also be pertinent. Accordingly, the burst reliabilities of two thin-walled 304 SS cylindrical vessels such as might be employed in liquid metal plants are estimated. A large vessel fabricated from rolled plate per ASME SA-240 and a smaller pipe sized vessel also fabricated from rolled plate per ASME SA-358 are considered. The vessels are sized to just meet the allowable ASME Code primary membrance stresses at 800 0 F (427 0 C). The bursting probability that the operating pressure is greater than the burst strength of the cylinders is calculated using stress-strength interference theory by direct Monte Carlo simulation on a high speed digital computer. A sensitivity study is employed to identify those design parameters which have the greatest effect on the reliability. The effects of preservice quality assurance defect inspections on the reliability are also evaluated parametrically

  12. An analytical model for shape memory alloy fiber-reinforced composite thin-walled beam undergoing large deflection

    Directory of Open Access Journals (Sweden)

    Yongsheng Ren

    2015-03-01

    Full Text Available The structural model of the thin-walled laminated beams with integral shape memory alloy active fibers and accounting for geometrically nonlinear is presented in this article. The structural modeling is split into two parts: a two-dimensional analysis over the cross section and a geometrically nonlinear analysis of a beam along the beam span. The variational asymptotic method is used to formulate the force–deformation relationship equations taking into account the presence of active shape memory alloy fibers distributed along the cross section of the beam. The geometrically nonlinear governing equations are derived using variational principle and based on the von Kármán-type nonlinear strain–displacement relations. The equations are then solved using Galerkin’s method and an incremental Newton–Raphson method. The validation for the proposed model has been carried out by comparison of the present results with those available in the literature. The results show that significant extension, bending, and twisting coupled nonlinear deflections occur during the phase transformation due to shape memory alloy actuation. The effects of the volume fraction of the shape memory alloy fiber and ply angle are also addressed.

  13. Parameter-free method for the shape optimization of stiffeners on thin-walled structures to minimize stress concentration

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang; Shibutan, Yoji [Osaka University, Osaka (Japan); Shimoda, Masatoshi [Toyota Technological Institute, Nagoya (Japan)

    2015-04-15

    This paper presents a parameter-free shape optimization method for the strength design of stiffeners on thin-walled structures. The maximum von Mises stress is minimized and subjected to the volume constraint. The optimum design problem is formulated as a distributed-parameter shape optimization problem under the assumptions that a stiffener is varied in the in-plane direction and that the thickness is constant. The issue of nondifferentiability, which is inherent in this min-max problem, is avoided by transforming the local measure to a smooth differentiable integral functional by using the Kreisselmeier-Steinhauser function. The shape gradient functions are derived by using the material derivative method and adjoint variable method and are applied to the H{sup 1} gradient method for shells to determine the optimal free-boundary shapes. By using this method, the smooth optimal stiffener shape can be obtained without any shape design parameterization while minimizing the maximum stress. The validity of this method is verified through two practical design examples.

  14. Study on the Surface Integrity of a Thin-Walled Aluminum Alloy Structure after a Bilateral Slid Rolling Process

    Directory of Open Access Journals (Sweden)

    Laixiao Lu

    2016-04-01

    Full Text Available For studying the influence of a bilateral slid rolling process (BSRP on the surface integrity of a thin-walled aluminum alloy structure, and revealing the generation mechanism of residual stresses, a self-designed BSRP appliance was used to conduct rolling experiments. With the aid of a surface optical profiler, an X-ray stress analyzer, and a scanning electron microscope (SEM, the differences in surface integrity before and after BSRP were explored. The internal changing mechanism of physical as well as mechanical properties was probed. The results show that surface roughness (Ra is reduced by 23.7%, microhardness is increased by 21.6%, and the depth of the hardening layer is about 100 μm. Serious plastic deformation was observed within the subsurface of the rolled region. The residual stress distributions along the depth of the rolling surface and milling surface were tested respectively. Residual stresses with deep and high amplitudes were generated via the BSRP. Based on the analysis of the microstructure, the generation mechanism of the residual stresses was probed. The residual stress of the rolling area consisted of two sections: microscopic stresses caused by local plastic deformation and macroscopic stresses caused by overall non-uniform deformation.

  15. Heat transfer improvement due to the imposition of non-uniform wall heating for in-tube laminar forced convection

    International Nuclear Information System (INIS)

    Hajmohammadi, M.R.; Poozesh, S.; Rahmani, M.; Campo, A.

    2013-01-01

    This paper explores the bearing that a non-uniform distribution of heat flux used as a wall boundary condition exerts on the heat transfer improvement in a round pipe. Because the overall heat load is considered fixed, the heat transfer improvement is viewed through a reduction in the maximum temperature (‘hot spot’) by imposing optimal distribution of heat flux. Two cases are studied in detail 1) fully developed and 2) developing flow. Peak temperatures in the heated pipe wall are calculated via an analytical approach for the fully developed case, while a numerical simulation based on CFD is employed for the developing case. By relaxing the heat flux distribution on the pipe wall, the numerical results imply that the optimum distribution of heat flux, which minimizes the peak temperatures corresponds with the ‘descending’ distribution. Given that the foregoing approach is quite different from the ‘ascending’ heat flux distribution recommended in the literature by means of the entropy generation minimization (EGM) method, it is inferred that the optimization of heat transfer and fluid flow, in comparison with the thermodynamic optimization, may bring forth quite different guidelines for the designs of thermal systems under the same constraints and circumstances. -- Highlights: • Considered the bearing of non-uniform distribution of heat flux on the hot spots. • Determined the optimal distribution of heat flux that minimizes the hot spots. • Results are compared with those obtained by EGM method

  16. Electronic setup for fluorescence emission measurements and long-time constant-temperature maintenance of Single-Walled Carbon Nano-Tubes in water solutions

    Directory of Open Access Journals (Sweden)

    De Rosa Matteo

    2017-03-01

    Full Text Available In our previous research we have observed that the fluorescence emission from water solutions of Single-Walled Carbon Nano-Tubes (SWCNT, excited by a laser with a wavelength of 830nm, diminishes with the time. We have already proved that such a fading is a function of the storage time and the storage temperature. In order to study the emission of the SWCNT as a function of these two parameters we have designed and realized a special measurement compartment with a cuvette holder where the SWCNT solutions can be measured and stored at a fixed constant temperature for periods of time as long as several weeks. To maintain the measurement setup under a constant temperature we have designed special experimental setup based on two Peltier cells with electronic temperature control.

  17. Assessment of Reusing 14-Ton, Thin-Wall, Depleted UF6 Cylinders as LLW Disposal Containers

    International Nuclear Information System (INIS)

    O'Connor, D.G.; Poole, A.B.; Shelton, J.H.

    2000-01-01

    Approximately 700,000 MT of DUF 6 is stored, or will be produced under a current agreement with the USEC, at the Paducah site in Kentucky, Portsmouth site in Ohio, and ETTP site in Tennessee. On July 21, 1998, the 105th Congress approved Public Law 105-204, which directed that facilities be built at the Kentucky and Ohio sites to convert DUF 6 to a stable form for disposition. On July 6, 1999, the Department of Energy (DOE) issued the ''Final Plan for the Conversion of Depleted Uranium Hexafluoride as Required by Public Law 105-204'', in which DOE committed to develop a ''Depleted Uranium Hexafluoride Materials Use Roadmap''. On September 1,2000, DOE issued the ''Draft Depleted Uranium Hexafluoride Materials Use Roadmap'' (Roadmap), which provides alternate paths for the long-term storage, beneficial use, and eventual disposition of each product form and material that will result from the DUF 6 conversion activity. One of the paths being considered for DUF 6 cylinders is to reuse the empty cylinders as containers to transport and dispose of LLW, including the converted DU. The Roadmap provides results of the many alternate uses and disposal paths for conversion products and the empty DUF 6 storage cylinders. As a part of the Roadmap, evaluations were conducted of cost savings, technical maturity, barriers to implementation, and other impacts. Results of these evaluations indicate that using the DUF 6 j storage cylinders as LLW disposal containers could provide moderate cost savings due to the avoided cost of purchasing LLW packages and the avoided cost of disposing of the cylinders. No significant technical or institutional .issues were identified that.would make using cylinders as LLW packages less effective than other disposition paths. Over 58,000 cylinders have been used, or will be used, to store DUF 6 . Over 5 1,000 of those cylinders are 14TTW cylinders with a nominal wall thickness of 5/16-m (0.79 cm). These- 14TTW cylinders, which have a nominal diameter

  18. Bioactivity and electrochemical behavior of hydroxyapatite-silicon-multi walled carbon nano-tubes composite coatings synthesized by EPD on NiTi alloys in simulated body fluid

    Energy Technology Data Exchange (ETDEWEB)

    Khalili, V., E-mail: V_khalili@sut.ac.ir [Department of Materials Engineering, Engineering Faculty, University of Bonab, Bonab (Iran, Islamic Republic of); Khalil-Allafi, J. [Research Center for Advanced Materials and Mineral Processing, Faculty of Materials Engineering, Sahand University of Technology, Tabriz (Iran, Islamic Republic of); Frenzel, J.; Eggeler, G. [Institute for Materials, Faculty of Mechanical Engineering, Ruhr-University Bochum, 44801 Bochum (Germany)

    2017-02-01

    In order to improve the surface bioactivity of NiTi bone implant and corrosion resistance, hydroxyapatite coating with addition of 20 wt% silicon, 1 wt% multi walled carbon nano-tubes and both of them were deposited on a NiTi substrate using a cathodic electrophoretic method. The apatite formation ability was estimated using immersion test in the simulated body fluid for 10 days. The SEM images of the surface of coatings after immersion in simulated body fluid show that the presence of silicon in the hydroxyapatite coatings accelerates in vitro growth of apatite layer on the coatings. The Open-circuit potential and electrochemical impedance spectroscopy were measured to evaluate the electrochemical behavior of the coatings in the simulated body fluid at 37 °C. The results indicate that the compact structure of hydroxyapatite-20 wt% silicon and hydroxyapatite-20 wt% silicon-1 wt% multi walled carbon nano-tubes coatings could efficiently increase the corrosion resistance of NiTi substrate. - Highlights: • The composite coatings of HA, Si and MWCNTs was prepared using electrophoretic deposition. • The presence of 1 wt.% MWCNTs in the HA coating provides more nucleation cites of apatite crystallites in SBF. • The presence of Si in HA coating increases the growth rate of apatite crystallites with the Ca/P atomic ratio of 1.67. • The EIS indicate the compact HA-20%Si and HA-20%Si-1%MWCNTs coatings efficiently increase corrosion resistance of NiTi. • The porous HA and HA-1%MWCNTs do not increase significantly corrosion resistance due to the easy diffusion path.

  19. An Applied Method for Predicting the Load-Carrying Capacity in Compression of Thin-Wall Composite Structures with Impact Damage

    Science.gov (United States)

    Mitrofanov, O.; Pavelko, I.; Varickis, S.; Vagele, A.

    2018-03-01

    The necessity for considering both strength criteria and postbuckling effects in calculating the load-carrying capacity in compression of thin-wall composite structures with impact damage is substantiated. An original applied method ensuring solution of these problems with an accuracy sufficient for practical design tasks is developed. The main advantage of the method is its applicability in terms of computing resources and the set of initial data required. The results of application of the method to solution of the problem of compression of fragments of thin-wall honeycomb panel damaged by impacts of various energies are presented. After a comparison of calculation results with experimental data, a working algorithm for calculating the reduction in the load-carrying capacity of a composite object with impact damage is adopted.

  20. Measuring a film flowing down a tube inner wall using a laser focus displacement meter and an image-processing method

    International Nuclear Information System (INIS)

    Takamasa, Tomoji; Kobayashi, Kenji

    1999-01-01

    To elucidate details of the fascinating nonlinear phenomena of waves on a film, spatial temporal knowledge of the interfacial waves is essential. This paper presents an experimental study on waves on a film flowing down a vertical tube inner wall measured with a laser focus displacement meter (LFD) and an image-processing method. As a result, the film thickness was measured within a 1% margin of error by LFD, and the wave velocity was measured within a 10% margin of error by the image-processing. The experimental results are summarized as follows: At entry length L = 900 mm, the wave becomes a two-wave system. In the entry region, L = 216 mm, and 400 mm, the wave amplitude decreases as the flow rate increases, in the same manner as that in a film flowing down a plate wall. The velocity measured by the image processing agreed well with that calculated using Nusselt's theoretical equation and the Ito-Sasaki empirical equation for Reynolds numbers < 250. (author)