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Sample records for thick section 9cr-1mo

  1. Some elevated temperature tensile and strain-controlled fatigue properties for a 9%Cr1Mo steel heat treated to simulate thick section material

    International Nuclear Information System (INIS)

    Sanderson, S.J.; Jacques, S.

    Current interest has been expressed in the usage of thick section 9%Cr1%Mo steel, particularly for UK Commercial Demonstration Fast Reactor (CDFR) steam generator tubeplates. This paper presents the results of some preliminary mechanical property test work on a single cast of the steel, heat treated to simulate heavy ruling sections encompassing thicknesses likely to be met in the CDFR context. The microstructures of the simulated thick section material were found to remain predominantly as tempered martensite even at the slowest transformation cooling rates used (50 deg. C/h). The effect of microstructure is reflected in the elevated temperature proof stress, tensile strength and strain-controlled fatigue endurance which were found to be comparable with the properties established for thin section normalised and tempered 9%Cr1%Mo steel. These results are extremely encouraging and, taken in conjunction with the results from other simulation work on this material, further demonstrate the potential of thick section 9%Cr1%Mo steel. (author)

  2. Weldability of 9 Cr- 1 Mo-Nb-V steel

    International Nuclear Information System (INIS)

    Kume, Ryoichi; Matsui, Kenji; Okabayashi, Hisaki

    1989-01-01

    The weldability of 9 Cr- 1 Mo-Nb-V steel was studied using casting, forging and heavy section pipe. The obtained results are as follows; (1) Minimum preheating temperature to prevent cold cracking in y groove restraint specimen is about 200degC, which is lower than the values estimated from the chemistry of 9 Cr- 1 Mo-Nb-V steel used and ordinary 2.25 Cr- 1 Mo steel. (2) The degrees in susceptibility of the cold cracking of weldments made with electrode of matching composition can be interpreted by cosidering relief of thermal shrinkage caused by martensitic transformation of weld metals which, then, lowers degree of residual stress in restraint condition. (3) The susceptibility to hot cracking is the same or less than that of Type 304 stainless steel and far less than that of Type 316 or Type 347 stainless steel. (4) Long time heating embrittlement phenomenon was not observed for 9 Cr- 1 Mo-Nb-V welded joints under the condition of 600degC for 5000 hours. (5) Newly developed 9 Cr- 1 Mo-Nb-V casting shows sufficient weldability for welding production. (author)

  3. 9 Cr-- 1 Mo steel material for high temperature application

    Science.gov (United States)

    Jablonski, Paul D; Alman, David; Dogan, Omer; Holcomb, Gordon; Cowen, Christopher

    2012-11-27

    One or more embodiments relates to a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650.degree. C. The 9 Cr-1 Mo steel has a tempered martensite microstructure and is comprised of both large (0.5-3 .mu.m) primary titanium carbides and small (5-50 nm) secondary titanium carbides in a ratio of. from about 1:1.5 to about 1.5:1. The 9 Cr-1 Mo steel may be fabricated using exemplary austenizing, rapid cooling, and tempering steps without subsequent hot working requirements. The 9 Cr-1 Mo steel exhibits improvements in total mass gain, yield strength, and time-to-rupture over ASTM P91 and ASTM P92 at the temperature and time conditions examined.

  4. Weldability of modified 9Cr-1Mo steel

    Energy Technology Data Exchange (ETDEWEB)

    King, J F; Sikka, V K; Santella, M L; Turner, J F; Pickering, E W

    1986-09-01

    The weldability of modified 9Cr-1Mo steel has been investigated by numerous organizations including Oak Ridge National Laboratory over a period of several years. The results of the various studies are summarized. Weldability evaluations have included hot cracking susceptibility, reheat cracking response, hydrogen-assisted cracking susceptibility, and the selection of consumables for three welding processes. Weldment mechanical properties have been determined for the gas tungsten arc, submerged arc, and shielded metal arc welding processes. Dissimilar metal weldments between modified 9Cr-1Mo steel and austenitic stainless steels have been produced with good results. Evaluation of the weldments and various tests has indicated that there are no major concerns regarding the weldability of modified 9Cr-1Mo steel.

  5. Creep life assessment of an overheated 9Cr-1Mo steel tube

    International Nuclear Information System (INIS)

    Mazaheri, M.; Djavanroodi, F.; Nikbin, K.M.

    2010-01-01

    Crude oil heater 9Cr-1Mo steel tubes from a refinery plant were studied, after 24 years of service at nominally 650 o C and 27 MPa, to predict their remanent lives. The investigation included dimensional, hardness and tensile measurements in addition to accelerated stress rupture tests between 650 o C and 700 o C and microstructural examination. Tube specimens were taken from two sections, the overheated side and the side which only saw the nominal operating temperature. The method employed involved the prediction of the increase in temperature with increasing sediment deposition during the operating life times using an FEM model. In addition the predicted temperatures are used to derive appropriate creep properties at relevant temperatures in a 3D pipe FEM creep analysis to predict the pipe deformation rate. All compare well with the actual service exposed pipe measurements and layer deposition. The overheated side revealed a small loss of creep strength in a stress rupture test. A layer of sediment (appr. 10 mm thickness) consisting basically of sintered carbon (coke) spread over the inside of the tube was acting as a thermal barrier causing the temperature to rise above 650 o C. Analysis for the overheated side predicted an upper bound temperature of ∼800 o C and a life of about 50 h suggesting that failure by creep rupture could occur rapidly in the sediment region. - Research highlights: →Remanent life of 9Cr-1Mo steel tubes after 24 year of service was predicted. →Accelerated creep testing and metallographic investigation was performed. →prediction of the increase in temperature with increasing sediment deposition was made using FEM. →3D pipe FEM creep analysis was used to predict the pipe bending deformation.

  6. Irradiation hardening of Mod.9Cr-1Mo steel

    International Nuclear Information System (INIS)

    Ryu, Woo-Seog; Kim, Sung-Ho; Choo, Kee-Nam; Kim, Do-Sik

    2009-01-01

    An irradiation test of Mod.9Cr-1Mo steel was carried out in the OR5 test hole of HANARO of a 30 MW thermal power at 390±10degC up to a fast neutron fluence of 4.4x10 19 (n/cm 2 ) (E > 1.0 MeV). The dpa of the irradiated specimens was evaluated to be 0.034 - 0.07. Tensile and impact tests of the irradiated Mod.9Cr-1Mo were done in the hot cell of the IMEF. The change of the tensile strength by irradiation was similar to the change of the yield strength. The increase of the yield and tensile strengths was up to 18% and 10% respectively. The elongation reduction of the weldment was up to 65%. (author)

  7. Effect of Alloy 625 Buffer Layer on Hardfacing of Modified 9Cr-1Mo Steel Using Nickel Base Hardfacing Alloy

    Science.gov (United States)

    Chakraborty, Gopa; Das, C. R.; Albert, S. K.; Bhaduri, A. K.; Murugesan, S.; Dasgupta, Arup

    2016-04-01

    Dashpot piston, made up of modified 9Cr-1Mo steel, is a part of diverse safety rod used for safe shutdown of a nuclear reactor. This component was hardfaced using nickel base AWS ER NiCr-B alloy and extensive cracking was experienced during direct deposition of this alloy on dashpot piston. Cracking reduced considerably and the component was successfully hardfaced by application of Inconel 625 as buffer layer prior to hardface deposition. Hence, a separate study was undertaken to investigate the role of buffer layer in reducing the cracking and on the microstructure of the hardfaced deposit. Results indicate that in the direct deposition of hardfacing alloy on modified 9Cr-1Mo steel, both heat-affected zone (HAZ) formed and the deposit layer are hard making the thickness of the hard layer formed equal to combined thickness of both HAZ and deposit. This hard layer is unable to absorb thermal stresses resulting in the cracking of the deposit. By providing a buffer layer of Alloy 625 followed by a post-weld heat treatment, HAZ formed in the modified 9Cr-1Mo steel is effectively tempered, and HAZ formed during the subsequent deposition of the hardfacing alloy over the Alloy 625 buffer layer is almost completely confined to Alloy 625, which does not harden. This reduces the cracking susceptibility of the deposit. Further, unlike in the case of direct deposition on modified 9Cr-1Mo steel, dilution of the deposit by Ni-base buffer layer does not alter the hardness of the deposit and desired hardness on the deposit surface could be achieved even with lower thickness of the deposit. This gives an option for reducing the recommended thickness of the deposit, which can also reduce the risk of cracking.

  8. Effect of Welding Processes on the Microstructure, Mechanical Properties and Residual Stresses of Plain 9Cr-1Mo Steel Weld Joints

    Science.gov (United States)

    Nagaraju, S.; Vasantharaja, P.; Brahadees, G.; Vasudevan, M.; Mahadevan, S.

    2017-12-01

    9Cr-1Mo steel designated as P9 is widely used in the construction of power plants and high-temperature applications. It is chosen for fabricating hexcan fuel subassembly wrapper components of fast breeder reactors. Arc welding processes are generally used for fabricating 9Cr-1Mo steel weld joints. A-TIG welding process is increasingly being adopted by the industries. In the present study, shielded metal arc (SMA), tungsten inert gas (TIG) and A-TIG welding processes are used for fabricating the 9Cr-1Mo steel weld joints of 10 mm thickness. Effect of the above welding processes on the microstructure evolution, mechanical properties and residual stresses of the weld joints has been studied in detail. All the three weld joints exhibited comparable strength and ductility values. 9Cr-1Mo steel weld joint fabricated by SMAW process exhibited lower impact toughness values caused by coarser grain size and inclusions. 9Cr-1Mo steel weld joint fabricated by TIG welding exhibited higher toughness due to finer grain size, while the weld joint fabricated by A-TIG welding process exhibited adequate toughness values. SMA steel weld joint exhibited compressive residual stresses in the weld metal and HAZ, while TIG and A-TIG weld joint exhibited tensile residual stresses in the weld metal and HAZ.

  9. The physical properties of 9 Cr-1 Mo steel from 300 to 1000 K

    International Nuclear Information System (INIS)

    Williams, R.K.; Graves, R.S.; McElroy, D.L.; Weaver, F.J.

    1983-01-01

    This chapter studies the thermal conductivity and expansion of an improved 9 Cr-1 Mo steel. Points out that the mechanical properties of 9 Cr-1 Mo steel can be significantly improved by heat-treating material that contains small additions of the carbide-forming elements V and Nb. Shows that the electron and phonon thermal conductivity components are both quite sensitive to Si content. Finds that the thermal expansion of standard commercial material is indistinguishable from that of the improved alloy

  10. TiC and 9Cr1MoV steel

    Indian Academy of Sciences (India)

    TECS

    Joining of composite, Al2O3–TiC, with heat-resistant 9Cr1MoV steel, was carried out by diffusion brazing technology ... terization of the Al2O3–TiC/9Cr1MoV joint was investigated by X-ray diffraction (XRD) and scanning electron microscope ..... Jahanmir S, Deckmap D E, Ives L K and Feldman A 1989 Mater. Res. Soc.

  11. Evaluation of creep damage in a welded joint of modified 9Cr-1Mo steel

    Science.gov (United States)

    Li, Yongkui; Monma, Yoshio; Hongo, Hiromichi; Tabuchi, Masaaki

    2010-10-01

    This paper aims to evaluate the creep damage of modified 9Cr-1Mo steel under 600 °C operating conditions, using constitutive equations based on the continuum damage mechanics. The accumulation of voids over a long period is believed to contribute to the formation of Type IV cracking, which in turn leads eventually to the failure of weldment under conditions of higher temperatures and lower stresses. Specimens of base metal, a simulated fine-grained heat affected zone, and a thin (thick) welded joint were kept under stress from 80 to 160 MPa at 600 °C. During the creep tests of thick plate welded joint specimens, the application of stress was suspended several times, and the creep damage as indicated by the void distribution was examined quantitatively using a laser microscope. The combined effect of the equivalent creep strain and the stress triaxial factor was considered and introduced into the constitutive equations with the aid of a finite element method. The logarithms of m and 1/λ in the continuum damage mechanics equations were determined to have a linear correlation with the ratio of the applied stress to the yield stress for homogeneous materials. In this way, the damage distribution and evolution in the fine-grained heat affected zone were evaluated successfully.

  12. Modification in the Microstructure of Mod. 9Cr-1Mo Ferritic Martensitic Steel Exposed to Sodium

    Science.gov (United States)

    Prasanthi, T. N.; Sudha, Cheruvathur; Paul, V. Thomas; Bharasi, N. Sivai; Saroja, S.; Vijayalakshmi, M.

    2014-09-01

    Mod. 9Cr-1Mo is used as the structural material in the steam generator circuit of liquid metal-cooled fast breeder reactors. Microstructural modifications on the surface of this steel are investigated after exposing to flowing sodium at a temperature of 798 K (525 °C) for 16000 hours. Sodium exposure results in the carburization of the ferritic steel up to a depth of ~218 µm from the surface. Electron microprobe analysis revealed the existence of two separate zones with appreciable difference in microchemistry within the carburized layer. Differences in the type, morphology, volume fraction, and microchemistry of the carbides present in the two zones are investigated using analytical transmission electron microscopy. Formation of separate zones within the carburized layer is understood as a combined effect of leaching, diffusion of the alloying elements, and thermal aging. Chromium concentration on the surface in the α-phase suggested possible degradation in the corrosion resistance of the steel. Further, concentration-dependent diffusivities for carbon are determined in the base material and carburized zones using Hall's and den Broeder's methods, respectively. These are given as inputs for simulating the concentration profiles for carbon using numerical computation technique based on finite difference method. Predicted thickness of the carburized zone agrees reasonably well with that of experiment.

  13. Reduction factors for creep strength and fatigue life of modified 9 Cr-1 Mo steel weldments

    International Nuclear Information System (INIS)

    Blass, J.J.; Battiste, R.L.; O'Connor, D.G.

    1991-01-01

    The provisions of ASME B ampersand PV Code Case N-47 currently include reduction factors for creep strength and fatigue life of weldments. To provide experimental confirmation of such factors for modified 9 Cr-1 Mo steel, tests of tubular specimens were conducted at 538 degree C (1000 degree F). Three creep-rupture specimens with longitudinal welds were tested in tension; and, of three with circumferential welds, two were tested in tension and one in torsion. In each specimen with a circumferential weld, a nonuniform axial distribution of strain was easily visible. The test results were compared to an existing empirical model of creep-rupture life. For the torsion test, the comparison was based on a definition of equivalent normal stress recently adopted in Code Case N-47. Some 27 fatigue specimens, with longitudinal, circumferential, or no welds, were tested under axial or torsional strain control. In specimens with welds, fatigue cracking initiated at fusion lines. In axial tests cracks grew in the circumferential direction, and in torsional tests cracks grew along fusion lines. The test results were compared to empirical models of fatigue life based on two definition of equivalent normal strain range. The results have provided some needed confirmation of the reduction factors for creep strength and fatigue life of modified 9 Cr-1 Mo steel weldments currently under consideration by ASME Code committees. 8 refs., 5 figs

  14. Basic investigation for life assessment technology of modified 9CR-1Mo steel

    Energy Technology Data Exchange (ETDEWEB)

    Okamura, Hiroyuki [Science Univ. of Tokyo (Japan); Ohtani, Ryuichi [Kyoto Univ. (Japan); Fujii, Kazuya [Japan Power Engineering and Inspection Corp., Tokyo (Japan); Kimura, Kazushige; Ishii, Ryuichi; Fujiyama, Kazunari; Hongo, Shigetada; Iseki, Takashi; Uchida, Hiroshi [Toshiba Corp., Kawasaki, Kanagawa (Japan)

    1998-11-01

    For the basic study of life assessment technologies for aged components made of mod.9Cr-1Mo steel, specimens were artificially deteriorated by aging, creep and fatigue tests at elevated temperatures. And metallurgical and mechanical properties were examined. The change in the precipitates caused the decrease in toughness. The creep damage in base metal corresponded to the decrease in hardness. The fatigue damage in base metal correlated to the maximum length of a crack among micro-cracks initiated during fatigue cycle. In the welded joint, the creep fracture occurred by the formation and growth of voids in the fine grained region of HAZ near base metal. The creep damage was associated with the increase in both number and area fraction of voids. (orig.)

  15. Fatigue crack growth and endurance data on 9% Cr 1% Mo steels for AGR applications

    International Nuclear Information System (INIS)

    Priddle, E.K.

    1987-01-01

    Experimental investigations have been carried out on 9%Cr 1%Mo steels to examine: (1) The significance of carburisation on the fatigue endurance of plain and welded boiler tubes, and tube spacer strip; (2) the high cycle fatigue endurance of spacer strip and spacer weld metal; (3) fatigue crack growth rates in spacer strip and spacer weld metal. This report summarises the results of these investigations and where necessary compares the data to that in current data sheets. The effects of carburisation are variable depending on the structure and type of carburisation. The fatigue endurance properties of spacer strip and spacer weld metal are also similar and need not be considered separately for assessment or design purposes. Fatigue crack growth rates in spacer strip and space weld metal are similar and are influenced by both stress ratio and temperature. A design curve from a fast reactor data sheet may be used as an upper bound to these fatigue crack growth results. (author)

  16. Heat treated 9 Cr-1 Mo steel material for high temperature application

    Science.gov (United States)

    Jablonski, Paul D.; Alman, David; Dogan, Omer; Holcomb, Gordon; Cowen, Christopher

    2012-08-21

    The invention relates to a composition and heat treatment for a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650.degree. C. The novel combination of composition and heat treatment produces a heat treated material containing both large primary titanium carbides and small secondary titanium carbides. The primary titanium carbides contribute to creep strength while the secondary titanium carbides act to maintain a higher level of chromium in the finished steel for increased oxidation resistance, and strengthen the steel by impeding the movement of dislocations through the crystal structure. The heat treated material provides improved performance at comparable cost to commonly used high-temperature steels such as ASTM P91 and ASTM P92, and requires heat treatment consisting solely of austenization, rapid cooling, tempering, and final cooling, avoiding the need for any hot-working in the austenite temperature range.

  17. In Situ Tensile Deformation and Residual Stress Measurement by Neutron Diffraction in Modified 9Cr-1Mo Steel

    Science.gov (United States)

    Shrestha, Triratna; Charit, Indrajit; Potirniche, Gabriel

    2015-12-01

    The deformation behavior of monolithic modified 9Cr-1Mo (Grade 91) steel during uniaxial tensile loading was studied using the in situ neutron diffraction technique. The residual stress distribution across gas tungsten arc welds in the Grade 91 steel was measured by the time-of-flight neutron diffraction method using the SMARTS diffractometer at Lujan Neutron Scattering Center, Los Alamos National Laboratory. Grade 91 plates were welded using the gas tungsten arc welding (GTAW) technique. The load sharing by different grain orientations was observed during the tensile loading. The residual stresses along three orthogonal directions were determined at the mid-thickness, 4.35 and 2.35 mm below the surface of both the as-welded and post-weld heat-treated plates. The residual stresses of the as-welded plates were compared with those of the post-weld heat-treated plates. The post-weld heat treatment significantly reduced the residual stress level in the base metal, the heat-affected zone, and the weld zone. Vickers microhardness across the weld zone of the as-welded and post-weld heat-treated specimens was evaluated and correlated with the observed residual stress profile and microstructure.

  18. Ratchetting deformation behavior of modified 9Cr-1Mo steel and applicability of existing constitutive models

    International Nuclear Information System (INIS)

    Yaguchi, Masatsugu; Takahashi, Yukio

    2001-01-01

    A series of ratchetting deformation tests was conducted on modified 9Cr-1Mo steel at 550degC under uniaxial and multiaxial stress conditions. Ratchetting behavior depended on various parameters such as mean stress, stress/strain rate and those range, hold time and prior cyclic deformation. Under uniaxial conditions, untraditional ratchetting behavior was observed; the ratchetting deformation rate was the fastest when the stress ratio was equal to -1, while no ratchetting deformation was predicted by conventional constitutive models. In order to discuss the reason for this untraditional ratchetting behavior, a lot of monotonic compression tests were conducted and compared with tension data. The material showed a difference of deformation resistance of about 30 MPa between tension and compression at high strain rates. Furthermore, the authors' previous model and Ohno-Wang model were applied to the test conditions to evaluate their description capability for ratchetting behavior of the material. It was shown that the authors' model has a tendency to overestimate the ratchetting deformation and that the Ohno-Wang model has a tendency to underestimate the uniaxial ratchetting deformation at small stress rates. (author)

  19. Relationship between austenite stability and martensite formation in modified 9Cr-1Mo steel

    International Nuclear Information System (INIS)

    Ning, Baoqun; Zhao, Jie

    2014-01-01

    Aimed at investigating the relationship between austenite stability and martensite formation in modified 9Cr-1Mo steel, the fully austenitized steel was cooled to a temperature above or below the start temperature of martensite transformation (M s o , 406 C), which occurs upon continuous cooling from the austenitizing temperature to room temperature, and held for different times (10 min, 25 min, and 45 min) followed by cooling to room temperature. The concept of primary and secondary martensite is introduced to indicate that two different, sequential, martensites formed in this processing. When cooled to 650 C or 450 C for different times, the austenite stability decreased with prolonged holding time, and during the subsequent cooling the primary martensite start temperature (M s ) was raised to a value higher than M s o . In contrast, M s was reduced to a level lower than M s o when cooled to 420 C or 410 C for 45 min. On the other hand, as the steel was isothermally quenched at temperatures below M s o , during the subsequent cooling a secondary martensite reaction could be observed, and the secondary martensite start temperature (M s ') decreased with holding time. Retained austenite in the form of thin films along martensite lath boundaries was obtained when cooled to 380 C or below for different times. (orig.)

  20. Modified 9Cr-1Mo steel for advanced steam generator applications

    International Nuclear Information System (INIS)

    Brinkman, C.R.; Alexander, D.J.; Maziasz, P.J.

    1990-01-01

    Results are reported from several types of mechanical property tests conducted on a number of commercial heats of modified 9Cr-1Mo steel. Data from long term creep-rupture tests conducted on base and weldment material were compared with an analytical model which has been shown to give good agreement between measured and predicted values. Weldment material had somewhat inferior creep-rupture strength in comparison to base material due to a soft zone at the edge of the HAZ. Data are presented from elevated temperature tensile and creep-rupture tests conducted n material thermally aged for periods of up to 75,000 h (8.6 years). Some reduction in strength was shown to occur in comparison to unaged material. Models were developed for predicting the reduction in short term elevated temperature tensile and yield strength for material thermally aged in the temperature range of 482 to 704 degree C. Results from Charpy impact tests conducted on material thermally aged at 538 degree C for periods of up to 75,000 h showed an increase in the ductile-brittle transition temperature. Finally, results from transmission electron microscopy studies were presented to explain changes in mechanical properties due to thermal aging. These observations showed that Laves phase precipitation and recovery occurs on prolonged exposure of this alloy in this temperature range. 9 refs

  1. Modified 9Cr-1Mo steel for advanced steam generator applications

    International Nuclear Information System (INIS)

    Brinkman, C.R.; Alexander, D.J.; Maziasa, P.J.

    1990-01-01

    Results are reported from several types of mechanical property tests conducted on a number of commercial heats of modified 9Cr-1Mo steel. Data from long term creep-rupture tests conducted on base and weldment material were compared with an analytical model which has been shown to give good agreement between measured and predicted values. Weldment material had somewhat inferior creep-rupture strength in comparison to base material due to a soft zone at the edge of the HAZ. Data are presented from elevated temperature tensile and creep-rupture tests conducted on material thermally aged for periods of up to 75,000 h (8.6 years). Some reduction in strength was shown to occur in comparison to unaged material. Models were developed for predicting the reduction in short term elevated temperature tensile and yield strength for material thermally aged in the temperature range of 482 to 704 degrees C. Results from Charpy impact tests conducted on material thermally aged at 538 degrees C for periods of up to 75,000 h show an increase in the ductile-brittle transition temperature

  2. High temperature tensile testing of modified 9Cr-1Mo after irradiation with high energy protons

    International Nuclear Information System (INIS)

    Toloczko, M.B.; Hamilton, M.L.; Maloy, S.A.

    2003-01-01

    This study examines the effect of tensile test temperatures ranging from 50 to 600 deg. C on the tensile properties of a modified 9Cr-1Mo ferritic steel after high energy proton irradiation at about 35-67 deg. C to doses from 1 to 3 dpa and 9 dpa. For the specimens irradiated to doses between 1 and 3 dpa, it was observed that the yield strength and ultimate strength decreased monotonically as a function of tensile test temperature, whereas the uniform elongation (UE) remained at approximately 1% for tensile test temperatures up to 250 deg. C and then increased for tensile test temperatures up to and including 500 deg. C. At 600 deg. C, the UE was observed to be less than the values at 400 and 500 deg. C. UE of the irradiated material tensile tested at 400-600 deg. C was observed to be greater than the values for the unirradiated material at the same temperatures. Tensile tests on the 9 dpa specimens followed similar trends

  3. Reduction factors for creep strength and fatigue life of modified 9Cr-1 Mo steel weldments

    International Nuclear Information System (INIS)

    Blass, J.J.; Battiste, R.L.; O'Connor, D.G.

    1991-01-01

    This paper reports on the provisions of ASME B and PV code Case N-47 currently include reduction factors for creep strength and fatigue life of weldments. To provide experimental confirmation of such factors for modified 9 Cr-1 Mo steel, tests of tubular specimens were conducted at 538 degrees C (1000 degrees F). Three creep-rupture specimens with longitudinal welds were tested in tension; and, of three with circumferential welds, two were tested in tension and one in torsion. In each specimen with a circumferential weld, a nonuniform axial distribution of strain was easily visible. The test results were compared to an existing empirical model of creep-rupture life. For the torsion test, the comparison was based on a definition of equivalent normal stress recently adopted in code Case N-47. some 27 fatigue specimens, with longitudinal, circumferential, or no welds, were tested under axial or torsional strain control. In specimens with welds, fatigue cracking initiated at fusion lines. In axial tests cracks grew in the circumferential direction, and in torsional tests cracks grew along fusion lines

  4. Microstructural changes during creep and life assessment of Mod.9Cr-1Mo steel

    International Nuclear Information System (INIS)

    Sawada, Kota; Maruyama, Kouichi; Komine, Ryuji; Nagae, Yuji.

    1997-01-01

    Several microstructural changes take place in a material during the course of creep. These changes can be a measure of creep life. In this paper, microstructural changes in Mod.9Cr-1Mo steel were studied and it was examined which is a good measure of creep life. Microscopic structural changes, such as void growth, lath structure uniformly oriented to the tensile axis and elongation of grains, are evident only in the necked portion of ruptured specimens. These macroscopic structural changes are not useful for creep life assessment. Lath width increases and dislocation density within lath decreases with increasing creep duration. These changes in dislocation substructure start in the early stage of creep life, and cause the increase of strain rate in the tertiary creep stage. The lath width and the dislocation density reach a saturated value before rupture. The saturated values are independent of temperature, and uniquely related to creep stress normalized by shear modulus. The extent of these microstructural changes are greater at lower stresses under which the material is practically used. These facts suggest that the lath width and the dislocation density within lath can be a useful measure of creep life. Hardness of crept specimens is closely related to the lath width and the dislocation density within lath. The changes of these microstructural features can be evaluated by the measurement of hardness. (author)

  5. High Temperature Properties Test and Research of 9Cr1Mo (P9) Seamless Pipe Used in Petrochemical Industry

    Science.gov (United States)

    Wang, Qijiang; Zhou, Yedong; Zhang, Qinglian

    Production technical process of BaoSteel-produced 9Cr1Mo (P9) seamless pipe is presented, and creep property of isothermal annealed state of that steel is studied under the temperatures of 550 °C, 600 °C, 650 °C, 700 °C. Also, isothermal extrapolation method and Larson-Miller method are employed to extrapolate creep rupture strength of the steel at the creep time of 20000h, 40000h, 60000h and 100000h. The results show that high temperature properties of BaoSteel-produced 9Cr1Mo (P9) seamless pipe meets the API 530 standard of USA and the SH/T3037 standard of China's petrochemical industry, and the steel can be used in large scale petroleum cracking equipment. Meantime, the comparison of creep properties at 650 °C and transient elevated temperature properties at different temperatures between isothermal annealed state and normalized + tempered state of 9Cr1Mo (P9) seamless pipe as well as the microstructure analysis show that the normalized + tempered 9Cr1Mo (P9) seamless pipe presents better high temperature properties.

  6. Laser welding and post weld treatment of modified 9Cr-1MoVNb steel.

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z. (Nuclear Engineering Division)

    2012-04-03

    Laser welding and post weld laser treatment of modified 9Cr-1MoVNb steels (Grade P91) were performed in this preliminary study to investigate the feasibility of using laser welding process as a potential alternative to arc welding methods for solving the Type IV cracking problem in P91 steel welds. The mechanical and metallurgical testing of the pulsed Nd:YAG laser-welded samples shows the following conclusions: (1) both bead-on-plate and circumferential butt welds made by a pulsed Nd:YAG laser show good welds that are free of microcracks and porosity. The narrow heat affected zone has a homogeneous grain structure without conventional soft hardness zone where the Type IV cracking occurs in conventional arc welds. (2) The laser weld tests also show that the same laser welder has the potential to be used as a multi-function tool for weld surface remelting, glazing or post weld tempering to reduce the weld surface defects and to increase the cracking resistance and toughness of the welds. (3) The Vicker hardness of laser welds in the weld and heat affected zone was 420-500 HV with peak hardness in the HAZ compared to 240 HV of base metal. Post weld laser treatment was able to slightly reduce the peak hardness and smooth the hardness profile, but failed to bring the hardness down to below 300 HV due to insufficient time at temperature and too fast cooling rate after the time. Though optimal hardness of weld made by laser is to be determined for best weld strength, methods to achieve the post weld laser treatment temperature, time at the temperature and slow cooling rate need to be developed. (4) Mechanical testing of the laser weld and post weld laser treated samples need to be performed to evaluate the effects of laser post treatments such as surface remelting, glazing, re-hardening, or tempering on the strength of the welds.

  7. 9Cr-1Mo martensitic alloys: effects of the nitrogen, niobium and vanadium additions on the microstructure, phase transformations and mechanical properties. Pt. 1 and 2

    International Nuclear Information System (INIS)

    Brachet, J.C.

    1991-06-01

    9Cr - 1Mo martensitic steels are leading candidate materials for fast reactor sub-assembly wrapper applications. The microstructure, phase transformations and mechanical properties of five 9Cr1Mo alloys containing N, Nb and/or V have been studied by dilatometry, optical and electron transmission microscopy and microanalysis

  8. Microstructure and annealing behavior of a modified 9Cr-1Mo steel after dynamic plastic deformation to different strains

    DEFF Research Database (Denmark)

    Zhang, Zhenbo; Mishin, Oleg; Tao, N.R.

    2015-01-01

    The microstructure, hardness and tensile properties of a modified 9Cr-1Mo steel processed by dynamic plastic deformation (DPD) to different strains (0.5 and 2.3) have been investigated in the as-deformed and annealed conditions. It is found that significant structural refinement and a high level...... in a loss of strength with only a small gain in ductility, coarsening combined with pronounced partial recrystallization enables a combination of appreciably increased ductility and comparatively high strength....

  9. Prediction and Monitoring Systems of Creep-Fracture Behavior of 9Cr-1Mo Steels for Reactor Pressure Vessels

    International Nuclear Information System (INIS)

    Potirniche, Gabriel; Barlow, Fred D.; Charit, Indrajit; Rink, Karl

    2013-01-01

    A recent workshop on next-generation nuclear plant (NGNP) topics underscored the need for research studies on the creep fracture behavior of two materials under consideration for reactor pressure vessel (RPV) applications: 9Cr-1Mo and SA-5XX steels. This research project will provide a fundamental understanding of creep fracture behavior of modified 9Cr-1Mo steel welds for through modeling and experimentation and will recommend a design for an RPV structural health monitoring system. Following are the specific objectives of this research project: Characterize metallurgical degradation in welded modified 9Cr-1Mo steel resulting from aging processes and creep service conditions; Perform creep tests and characterize the mechanisms of creep fracture process; Quantify how the microstructure degradation controls the creep strength of welded steel specimens; Perform finite element (FE) simulations using polycrystal plasticity to understand how grain texture affects the creep fracture properties of welds; Develop a microstructure-based creep fracture model to estimate RPVs service life; Manufacture small, prototypic, cylindrical pressure vessels, subject them to degradation by aging, and measure their leak rates; Simulate damage evolution in creep specimens by FE analyses; Develop a model that correlates gas leak rates from welded pressure vessels with the amount of microstructural damage; Perform large-scale FE simulations with a realistic microstructure to evaluate RPV performance at elevated temperatures and creep strength; Develop a fracture model for the structural integrity of RPVs subjected to creep loads; and Develop a plan for a non-destructive structural health monitoring technique and damage detection device for RPVs.

  10. Prediction and Monitoring Systems of Creep-Fracture Behavior of 9Cr-1Mo Steels for Teactor Pressure Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Potirniche, Gabriel [Univ. of Idaho, Moscow, ID (United States); Barlow, Fred D. [Univ. of Idaho, Moscow, ID (United States); Charit, Indrajit [Univ. of Idaho, Moscow, ID (United States); Rink, Karl [Univ. of Idaho, Moscow, ID (United States)

    2013-11-26

    A recent workshop on next-generation nuclear plant (NGNP) topics underscored the need for research studies on the creep fracture behavior of two materials under consideration for reactor pressure vessel (RPV) applications: 9Cr-1Mo and SA-5XX steels. This research project will provide a fundamental understanding of creep fracture behavior of modified 9Cr-1Mo steel welds for through modeling and experimentation and will recommend a design for an RPV structural health monitoring system. Following are the specific objectives of this research project: Characterize metallurgical degradation in welded modified 9Cr-1Mo steel resulting from aging processes and creep service conditions; Perform creep tests and characterize the mechanisms of creep fracture process; Quantify how the microstructure degradation controls the creep strength of welded steel specimens; Perform finite element (FE) simulations using polycrystal plasticity to understand how grain texture affects the creep fracture properties of welds; Develop a microstructure-based creep fracture model to estimate RPVs service life; Manufacture small, prototypic, cylindrical pressure vessels, subject them to degradation by aging, and measure their leak rates; Simulate damage evolution in creep specimens by FE analyses; Develop a model that correlates gas leak rates from welded pressure vessels with the amount of microstructural damage; Perform large-scale FE simulations with a realistic microstructure to evaluate RPV performance at elevated temperatures and creep strength; Develop a fracture model for the structural integrity of RPVs subjected to creep loads; and Develop a plan for a non-destructive structural health monitoring technique and damage detection device for RPVs.

  11. Effect of dynamic plastic deformation on microstructure and annealing behaviour of modified 9Cr-1Mo steel

    DEFF Research Database (Denmark)

    Zhang, Zhenbo; Mishin, Oleg V.; Tao, N. R.

    2015-01-01

    The effect of dynamic plastic deformation on the microstructure of a modified 9Cr - 1Mo steel has been investigated in comparison with the effect of quasi- static compression. It is found that the boundary spacing after dynamic plastic deformation is smaller and the hardness is higher than those...... after quasi- static compression. The microstructure after dynamic plastic deformation is however less stable than the microstructure after quasi- static compression. Annealing at 675 and 700 degrees C leads to structural coarsening and recrystallisation in each sample, but with recrystallisation...... occurring faster in the sample annealed after dynamic plastic deformation. The lower thermal stability of the microstructure produced by dynamic plastic deformation is attributed to a higher driving force for recrystallisation in the dynamically deformed material....

  12. Image analysis measurements of prior austenitic grain size of 9Cr-1Mo martensitic steels in function of the austenitization conditions. Quantification par analyse d'images de la taille de l'ancien grain austenitique d'aciers martensitiques 9Cr-1Mo

    Energy Technology Data Exchange (ETDEWEB)

    Barcelo, F.; Brachet, J.C. (CEA Centre d' Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Technologie des Materiaux)

    1994-02-01

    The size grain of the high temperature phase (austenite) can influence mechanical properties as well as some physical properties of 9Cr-1Mo martensitic steels. Automated image analysis makes it possible to quantify the size of an austenitic grain with respect to the heat treatment conditions of austenitization (time-temperature). The results obtained on a 9Cr-1Mo steel have made it possible to describe the growth kinetics of the austenitic grain of this steel. (authors). 21 refs., 14 figs.

  13. Effects of alloying elements and constituent phases on long-term creep strength of modified 9Cr-1Mo steel

    Energy Technology Data Exchange (ETDEWEB)

    Tokunaga, Tatsuya; Masuyama, Fujimitsu [Kyushu Institute of Technology, Kitakyushu (Japan). Dept. of Applied Science for Integrated System Engineering; Consortium of JRCM (The Japan Research and Development Center for Metals) ' Fundamental Studies on Technologies for Steel Materials with Enhanced Strength and Function' (Japan); Yoshida, Kohei [Mitsui High-tec Inc. (Japan); Sakanaba, Masaki [Mitsubishi Heavy Industries Ltd. (Japan)

    2010-07-01

    The effect of the alloying elements and constituent phases on the long-term creep strength of modified 9Cr-1Mo steel has been investigated using creep data from 34 heats of this steel. The creep rupture strength for 10{sup 5} h at 600 C was evaluated using the Larson-Miller parametric method, and the constituent phases and their composition at 600 C were obtained from thermodynamic equilibrium calculations. From various alloying elements, the long-term creep rupture strength was found to depend on the Cr, Mo, V, and N content. Regarding the effect of the constituent phases, the long-term creep rupture strength increased with increasing amount of NaCl-type carbonitride, MX (NbX + VX), and in particular, materials with higher VX/NbX ratios tended to exhibit higher creep strength. Furthermore, the enrichment of Mo in the M{sub 23}C{sub 6} carbide rather than in the bcc matrix may be effective in maintaining a higher creep strength. (orig.)

  14. Microstructure of 9 Cr-1 MoVNb steel irradiated to 40 dpa at elevated temperatures in HFIR

    Energy Technology Data Exchange (ETDEWEB)

    Vitek, J.M.; Klueh, R.L.

    1983-01-01

    As part of an effort by the Office of Fusion Energy to evaluate the irradiation behavior of ferritic steels, a 9 Cr-1 MoVNb alloy was irradiated in HFIR to a dose of approx. 36 dpa at temperatures of 300, 400, 500, and 600/sup 0/C. In addition to the displacement damage produced during irradiation, a transmutation reaction of nickel during HFIR irradiation resulted in the simultaneous production of approx. 30 at. ppM He. Electron microscopy disks in the normalized and tempered condition were irradiated, and the microstructures were evaluated as a function of irradiation temperature. A few small cavities were observed after irradiation at 300, 500, and 600/sup 0/C. However, a pronounced cavity microstructure was found after irradiation at 400/sup 0/C. At this temperature, the cavities had a volume-averaged diameter of 15 nm and a concentration of 1.1 x 10/sup 21/ m/sup -3/, resulting in a void-swelling contribution of 0.19%. The cavities at 400/sup 0/C were homogeneously distributed throughout the tempered martensite matrix, and showed no preference for lath boundaries or precipitate interfaces. The results are compared to those recently reported on a similarly irradiated 12 Cr-1 MoVW ferritic steel.

  15. Creep-fatigue evaluation method for weld joint of Mod.9Cr-1Mo steel Part II: Plate bending test and proposal of a simplified evaluation method

    International Nuclear Information System (INIS)

    Ando, Masanori; Takaya, Shigeru

    2016-01-01

    Highlights: • Creep-fatigue evaluation method for weld joint of Mod.9Cr-1Mo steel is proposed. • A simplified evaluation method is also proposed for the codification. • Both proposed evaluation method was validated by the plate bending test. • For codification, the local stress and strain behavior was analyzed. - Abstract: In the present study, to develop an evaluation procedure and design rules for Mod.9Cr-1Mo steel weld joints, a method for evaluating the creep-fatigue life of Mod.9Cr-1Mo steel weld joints was proposed based on finite element analysis (FEA) and a series of cyclic plate bending tests of longitudinal and horizontal seamed plates. The strain concentration and redistribution behaviors were evaluated and the failure cycles were estimated using FEA by considering the test conditions and metallurgical discontinuities in the weld joints. Inelastic FEA models consisting of the base metal, heat-affected zone and weld metal were employed to estimate the elastic follow-up behavior caused by the metallurgical discontinuities. The elastic follow-up factors determined by comparing the elastic and inelastic FEA results were determined to be less than 1.5. Based on the estimated elastic follow-up factors obtained via inelastic FEA, a simplified technique using elastic FEA was proposed for evaluating the creep-fatigue life in Mod.9Cr-1Mo steel weld joints. The creep-fatigue life obtained using the plate bending test was compared to those estimated from the results of inelastic FEA and by a simplified evaluation method.

  16. Observation of thermo-mechanical effect in D9 alloy and modified 9Cr-1Mo steel and structural studies using neutron diffraction

    International Nuclear Information System (INIS)

    Sivabharathy, M.; Sakthipandi, K.; Senthilkumar, A.

    2016-01-01

    Ti-modified 15Cr-15Ni-2.2Mo stainless steel, D9, is the candidate material for the structural applications in the fast reactor environment. Optimum amount of minor alloying elements and proper thermo-mechanical treatments are known to improve and enhance the resistance to irradiation induced void swelling. Modified 9Cr - 1Mo steel is an excellent properties high pressure tubes and headers in boilers as a substitute to austenitic stainless steels and was found to have good void swelling resistance under fast neutron environment. Sivabharathy et al reported that photoacoustic (PA) measurements are carried out on modified 9Cr-1Mo steel to find out thermal diffusivity and thermal conductivity. The aim of the present investigation will be to evaluate the thermal properties and structural studies of this material at different temperatures. Scanning electron microscopy (SEM) was used to study structure and morphology of the material. The results are correlated and compare to the literature. Structural studies of D9 alloy and Modified 9Cr-1Mo Steel by wide-angle neutron scattering work is under process. (author)

  17. Quantification by image analysis of grain size of the high temperature phase (austenite) of martensitic steels 9Cr-1Mo. Quantification par analyse d'images de la taille de grain de la phase haute temperature (austenite) d'aciers martensitiques 9Cr-1Mo

    Energy Technology Data Exchange (ETDEWEB)

    Barcelo, F.; Brachet, J.C. (CEA Centre d' Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Technologie des Materiaux)

    1993-09-01

    In martensitic steels, the austenitic grain size before transformation may influence mechanical properties. 9Cr-1Mo steel (EM10) is used in hexagonal pipes fabrication in fast neutrons reactors. Image analysis allows to quantify the older grain size in function of the austenization heat treatment conditions. (A.B.). 2 figs.

  18. Cooperation on impingement wastage experiment of Mod. 9Cr-1Mo steel using SWAT-1R sodium-water reaction test facility

    International Nuclear Information System (INIS)

    Beauchamp, F.; Allou, A.; Nishimura, M.; Umeda, R.

    2013-01-01

    Conclusion: • 6 experiments were carried out in the SWAT-1R facility of JAEA Oarai R&D Center to study the wastage resistance of the Mod. 9Cr-1Mo steel (T91) straight tubes. • These experiments were performed under the cooperation between CEA and JAEA. • The experiments were conducted successfully: - all the tubes were punctured by the reaction jet, - wastage and steam/water leak rates were obtained, - experimental results brought some new determining sets of wastage data on T91. • This fruitful cooperation has contributed to: - expanding the wastage database on T91, - upgrading wastage rates prediction from modelling, - the safety demonstration of future steam generators units

  19. An analysis of a set of creep data for a 9Cr-1Mo-0.2V (P91 type) steel

    International Nuclear Information System (INIS)

    Cadek, J.; Sustek, V.; Pahutova, M.

    1997-01-01

    Recently published creep data for a 9Cr-1Mo-0.2V steel are analysed and an attempt is made to interpret them applying the concept of thermally activated detachment of dislocations from carbide particles as the rate controlling process. For the data, very high and stress dependent apparent activation energy of creep, Q c , and very high and temperature dependent apparent stress exponent, m c , are characteristic. The modelling of creep behavior applying the above mentioned concept is shown to fail to account for this temperature and applied stress dependence of minimum creep strain rate and/or the values of Q c and m c following from the data analysis. It is suggested that the behavior of the dislocation substructure, which is affected by the presence of carbide particles, must be introduced into any model to adequately describe the unusual creep behavior of the steel of interest. (orig.)

  20. Inelastic behavior of modified 9Cr-1 Mo steel under basic loading conditions at elevated temperature and evaluation of two unified constitutive models

    International Nuclear Information System (INIS)

    Tanaka, Eiichi; Mizuno, Mamoru.

    1993-01-01

    The purposes of this paper are to elucidate fundamental material properties of modified 9Cr-1 Mo steel as a candidate material for next-generation fast breeder reactors and to obtain information for the formulation of a practical unified constitutive model. For these purposes, monotonous tension, uniaxial symmetric cycles, uniaxial symmetric cycles with hold time, creep, stress control uniaxial symmetric cycles, cyclic relaxation and circular cyclic loading tests are performed. Then these results are simulated by two unified constitutive models, i.e. the Chaboche model and Bodner-Partom model. The results of simulation show that the Chaboche model can describe all the experimental results with relatively high accuracy, and that the identification of material constants of the model is easy. The Bodner-Partom model can similarly describe the results, but the determination of material constants is difficult. (author)

  1. Cyclic creep, mechanical ratchetting and amplitude history dependence of modified 9Cr-1Mo steel and evaluation of unified constitutive models

    International Nuclear Information System (INIS)

    Tanaka, Eiichi; Yamada, Hiroshi

    1993-01-01

    The purpose of the present paper is to elucidate inelastic behavior of modified 9Cr-1Mo steel as a candidate material for the next-generation fast breeder reactor and to provide the information for the formulation of a unified constitutive model. For this purpose, cyclic creep, mechanical ratchetting and amplitude history dependence of cyclic hardening were first examined at 550degC. As a result, systematic cyclic creep and mechanical ratchetting behavior were observed under various loading conditions, and little amplitude history dependence was found. Then these results were simulated by three unified constitutive models, i.e. the Chaboche, Bodner-Partom and modified Chaboche models. The simulated results show that these models cannot describe the cyclic creep and mechanical ratchetting behavior with high accuracy, but succeed in describing the inelastic behavior of amplitude variation experiments. (author)

  2. Thermomechanical Model and Bursting Tests to Evaluate the Risk of Swelling and Bursting of Modified 9Cr-1Mo Steel Steam Generator Tubes during a Sodium-Water Reaction Accident

    Directory of Open Access Journals (Sweden)

    C. Bertrand

    2014-01-01

    Full Text Available The MECTUB code was developed to evaluate the risk of swelling and bursting of Steam Generator (SG tubes. This code deals with the physic of intermediate steam-water leaks into sodium which induce a Sodium-Water Reaction (SWR. It is based on a one-dimensional calculation to describe the thermomechanical behavior of tubes under a high internal pressure and a fast external overheating. The mechanical model of MECTUB is strongly correlated with the kind of the material of the SG tubes. It has been developed and validated by using experiments performed on the alloy 800. A change to tubes made of Modified 9Cr-1Mo steel requires more knowledge of Modified 9Cr-1Mo steel behavior which influences the bursting time at high temperatures (up to 1200°C. Studies have been initiated to adapt the mechanical model and to qualify it for this material. The first part of this paper focuses on the mechanical law modelling (elasticity, plasticity, and creep for Modified 9Cr-1Mo steel and on overheating thermal data. In a second part, the results of bursting tests performed on Modified 9Cr-1Mo tubes in the SQUAT facility of CEA are used to validate the mechanical model of MECTUB for the Modified 9Cr-1Mo material.

  3. Experimental study and modelling of high temperature creep flow and damage behaviour of 9Cr1Mo-NbV steel weldments; Etude experimentale et modelisation, du comportement, de l'endommagement et de la rupture en fluage a haute temperature de joint soudes en acier 9Cr1Mo-NbV

    Energy Technology Data Exchange (ETDEWEB)

    Gaffard, V

    2004-12-15

    Chromium martensitic stainless steels are under development since the 70's with the prospect of using them as structural components in thermal and nuclear power plants. The modified 9Cr1Mo-NbV steel is already used, especially in England and Japan, as a material for structural components in thermal power plants where welding is a commonly used joining technique. New generations of chromium martensitic stainless steels with improved mechanical properties for high pressure and temperature use are currently under development. However, observations of several in-service premature failures of welded components in 9Cr1Mo-NbV steel, outline a strong need for understanding the high temperature creep flow and damage behaviour of 9Cr1Mo-NbV steels and weldments. The present study aimed at experimentally determining and then modelling the high temperature creep flow and damage behaviour of both 9Cr1Mo-NbV steels and weldments (typically in the temperature range from 450 C to 650 C). The base metal was first studied as the reference material. It was especially evidenced that tempered chromium martensitic steels exhibit a change in both creep flow and damage behaviour for long term creep exposure. As a consequence, the classically performed extrapolation of 1,000 hours creep data to 100,000 hours creep lifetime predictions might be very hazardous. Based on experimental observations, a new model, integrating and coupling multiple creep flow and damage mechanisms, was developed in the framework of the mechanics of porous media. It was then successfully used to represent creep flow and damage behaviour of the base metal from high to low stress levels even for complex multiaxial loading conditions. Although the high temperature creep properties of the base metal are quite good, the occurrence of premature failure in weldments in high temperature creep conditions largely focused the attention of the scientific community. The lower creep strength of the weld component was also

  4. Residual stress measurements by neutron diffraction in laser and electron beam welded joints in 9Cr-1Mo(V, Nb) steel plates

    International Nuclear Information System (INIS)

    Kumar, Santosh; Viswanadham, C.S.; Bhanumurthy, K.; Dey, G.K.; Kundu, Amrita; Bouchard, P.J.

    2014-01-01

    Residual stresses are invariably associated with welded joints and have serious implications for integrity of welded components in service conditions. Laser and electron beam welding produces weld joints with narrow fusion zone and heat affected zone. Therefore, there exists very high spatial gradient of residual stresses across the weld joints; measurement of which is indeed a challenging task. Residual stress measurements in laser and electron beam welded 9Cr-1Mo (V, Nb) steel plates were carried out by neutron diffraction. Measurements for laser welded plates were carried out using monochromatic neutron beam at ILL, France and that for electron beam welded plates were carried out using white neutron beam at ISIS, UK. Measurements were made across the weld joints as well as along the weld centre-line for the three orthogonal components-longitudinal, transverse and normal of the residual stress. The cross-weld residual stress profile showed a low tensile/compressive trough in the fusion zone and a high tensile peak on the either side of the joint in the parent metal just outside of metallurgical HAZ. Besides, longitudinal and normal components of the residual stress are significant while the transverse component is the least significant. Residual stress profiles showed very similar characteristics in the weld joints made by laser and electron beam welding processes. These results are presented in this paper and discussed in the context of the metallurgical attributes of the material

  5. Impurity Antimony-Induced Creep Property Deterioration and Its Suppression by Rare Earth Ceriumfor a 9Cr-1Mo Ferritic Heat-Resistant Steel

    Directory of Open Access Journals (Sweden)

    Yewei Xu

    2016-08-01

    Full Text Available The high temperature creep properties of three groups of modified 9Cr-1Mo steel samples, undoped, doped with Sb, and doped with Sb and Ce, are evaluated under the applied stresses from 150 MPa to 210 MPa and at the temperatures from 873–923 K. The creep behavior follows the temperature-compensated power law as well as the Monkman-Grant relation. The creep activation energy for the Sb-doped steel (519 kJ/mol is apparently lower than that for the undoped one (541 kJ/mol, but it is considerably higher for the Sb+Ce-doped steel (621 kJ/mol. Based on the obtained relations, both the creep lifetimes under 50 MPa, 80 MPa, and 100 MPa in the range 853–923 K and the 105 h creep rupture strengths at 853 K, 873 K, and 893 K are predicted. It is demonstrated that the creep properties of the Sb-doped steel are considerably deteriorated but those of the Sb+Ce-doped steel are significantly improved as compared with the undoped steel. Microstructural and microchemical characterizations indicate that the minor addition of Ce can stabilize the microstructure of the steel by segregating to grain boundaries and dislocations, thereby offsetting the deleterious effect of Sb by coarsening the microstructure and weakening the grain boundary.

  6. Long-term creep-fatigue life property of Mod.9Cr-1Mo steel for steam generator material in FBR

    International Nuclear Information System (INIS)

    Extensive research is being executed to establish creep-fatigue life evaluation methodology for Mod.9Cr-1Mo steel which is the principal candidate material of steam generators in Demonstration Fast Breeder Reactor. Previous studies showed that the features of the creep-fatigue life property of the steel are small life reduction by tensile strain hold and significant reduction in compressive hold tests due to oxidation effect. Most of the experiments, however, were conducted under relatively short-term hold conditions and the failure life properties under long-term hold conditions have not yet been clarified. In order to investigate the oxidation and long-term strain hold effects on the creep-fatigue life property, the crack propagation tests in vacuum and air conditions, and the long-term creep-fatigue tests, up to 10 hours hold time per cycle, were performed. As a result, it was found that the significant life reduction occurred by introducing the tensile strain hold longer than 1 hour because of increase of the grain boundary damage due to cavity nucleation, and that the life reduction in compressive hold was caused by acceleration of the crack propagation rate due to accumulation of the tensile strain in center of the specimen. (author)

  7. Effect of prior-austenite grain refinement on microstructure, mechanical properties and thermal embrittlement of 9Cr-1Mo-0.1C steel

    Science.gov (United States)

    Karthikeyan, T.; Dash, Manmath Kumar; Ravikirana; Mythili, R.; Panneer Selvi, S.; Moitra, A.; Saroja, S.

    2017-10-01

    The effect of 'conventional normalizing and tempering' (CNT) and 'double austenitization based normalizing and tempering' (DNT) heat treatments on the microstructure, tensile, creep and impact toughness properties of 9Cr-1Mo steel has been studied. The tempered martensite microstructure obtained through DNT treatment exhibited smaller sizes of prior-austenite grains/martensite packets (28 μm/11 μm) compared to the CNT treatment (44 μm/14 μm). The tempered martensite morphology was largely retained after long-term thermal aging at 550 °C/5000 h, while the M23C6 and M2(C,N) type of precipitates were found to act as nucleation sites for precipitation of brittle Fe2Mo Laves phase. The grain refinement by DNT was found to be beneficial for minimizing the ductile-to-brittle transition characteristics (25 °C lower ductile-to-brittle transition temperature and 70 J higher upper shelf energy) over the CNT. Thermal embrittlement occurred in both heated treated steels, but the transition temperature of aged DNT steel remained below room temperature. Fractured Charpy specimens revealed ductile failure by void coalescence for high temperature tests, and a quasi-cleavage fracture at low temperatures with few isolated occurrence of intergranular crack in thermal embrittled steel. The DNT treated steel resulted in similar or better tensile and creep properties, when compared to the CNT treatment. The homogeneous fine grained tempered martensite microstructure obtained by DNT treatment resulted in improved embrittlement resistance and mechanical properties over the conventional treatment.

  8. Void formation and helium effects in 9Cr-1MoVNb and 12Cr-1MoVW steels irradiated in HFIR and FFTF at 400/degree/C

    International Nuclear Information System (INIS)

    Maziasz, P.J.; Klueh, R.L.

    1988-01-01

    Martensitic/ferritic 9Cr-1MoVNb and 12Cr-1MoVW steels doped with up to 2 wt% Ni have up to 450 appm He after HFIR irradiation to /approximately/38 dpa, but only 5 appm He after 47 dpa in FFTF. No fine He bubbles and few or no larger voids were observable in any of these steels after FFTF irradiation at 407/degree/C. By contrast, many voids were found in the undoped steels (30-90 appm He) irradiated in HFIR at 400/degree/C, while voids plus many more fine He bubbles were found in the Ni-doped steels (400-450 appm He). Irradiation in both reactors at /approximately/400/degree/C produced significant changes in the as-tempered lath/subgrain boundary, dislocation, and precipitation structures that were sensitive to alloy composition, including doping with Ni. However, for each specific alloy the irradiation-produced changes were exactly the same comparing samples irradiated in FFTF and HFIR, particularly the Ni-doped steels. Therefore, the increased void formation appears solely due to the increased helium generation found in HFIR. While the levels of void swelling are relatively low after 37-39 dpa in HFIR (0.1-0.4%), details of the microstructural evolution suggest that void nucleation is still progressing, and swelling could increase with dose. The effect of helium on void swelling remains a valid concern for fusion application that requires higher dose experiments. 15 refs., 14 figs., 8 tabs

  9. Influencia de la composición y tratamiento térmico sobre el comportamiento a fluencia de aceros ferrítico-martensíticos del tipo 9Cr1MoVNb utilizados en calderas supercríticas

    Directory of Open Access Journals (Sweden)

    Gutiérrez Urrutia, I.

    2000-06-01

    Full Text Available In the present investigation, creep behaviour on various ferritic-martensitic steels (type 9Cr1MoVNb from last generation were studied. They’re amply used as high pressure and temperature tubes in supercritical boilers for advanced thermoelectric plant. The material used was produced with vacuum high frecuency induction furnace hot-rolling followed by normalizing plus and tempering heat treatments. Creep testing carry out with different stress (also constant lower than yield strength (σ < Re and temperatures at 600±50ºC. Influence by variation of some chemical elements (B, Ti, V, Nb, V, C, as well assessment Larson-Miller, Manson-Haferd and Orr-Sherby-Dorn parameters, they’re likewise studied.

    Se estudia el comportamiento a fluencia de varios aceros ferrítico-martensíticos de última generación, del tipo 9Cr1MoVNb, que son ampliamente utilizados como tubos presurizados de alta temperatura en calderas supercríticas para centrales térmicas avanzadas de producción de energía eléctrica. El material utilizado fue fabricado en hornos de inducción de alta frecuencia y al vacío, laminado en caliente y posteriormente aplicado diferentes tratamientos térmicos de Normalizado y Revenido. En los ensayos de fluencia se aplicaron diferentes y ctes. σ < Re y temperaturas de 550, 600 y 650º C. La influencia de la variación de determinados elementos (C, N, V, Nb, Ti, B de su composición química así como observar los valores que toman los parámetros de Larson-Miller, Manson-Haferd y Orr-Sherby-Dorn, son asimismo contemplados.

  10. Change of Mechanical Properties during Creep Deformation in Modified 9Cr-1Mo Steel

    International Nuclear Information System (INIS)

    Kim, Sung Ho; Han, Chang Hee; Ryu, Woo Seog

    2005-01-01

    9-12% Cr-Mo ferritic/martensitic steels are widely used as high temperature materials in the power plants and chemical industries due to their high strength and thermal conductivity, low thermal expansion, and good resistance to corrosion. Owing to the better irradiation characteristics (e.g. excellent irradiation swelling resistance) of these steels than austenitic alloys they have been receiving attention for the application to the fuel cladding or core structure of various advanced nuclear reactors. Since the operating temperature and pressure of advanced nuclear reactors are supposed to be higher than those of light water reactors, high temperature mechanical properties and microstructural stability of cladding and core structural materials of advanced nuclear reactors is very important. Material softening is the main physical phenomenon observed in the crept material. The decrease of the matrix strength by the material softening occurred during creep deformation. When the strength of the matrix decreased to a certain value by creep deformation, the specimen ruptured. The strength changed with applied stress. The ratio of matrix yield strength to applied stress changed from 1.35 at high applied stress to 2.45 at low applied stress. In the present work, we evaluated material softening kinetics by measuring the change of mechanical properties during creep deformation with Indentation typed Tensile Test System (AIS 2000) and Vickers hardness test

  11. Cutting work in thick section cryomicrotomy.

    Science.gov (United States)

    Saubermann, A J; Riley, W D; Beeuwkes, R

    1977-09-01

    The forces during cryosectioning were measured using miniature strain gauges attached to a load cell fitted to the drive arm of the Porter-Blum MT-2 cryomicrotome. Work was calculated and the data normalized to a standard (1 mm X 1 mm X 0.5 micrometer) section. Thermal energy generated was also calculated. Five parameters were studied: cutting angle, thickness, temperature, hardness, and block shape. Force patterns could be divided into three major groups thought to represent cutting (Type I), large fracture planes greater than 10 micrometer in length (Type II), and small fracture planes less than 10 micrometer in length (Type III). Type I and Type II produced satisfactory sections. Work in cutting ranged from an average of 78.4 muJ to 568.8 muJ. Cutting angle and temperature had the greatest effect on sectioning. Heat generated would be sufficient to cause through-section melting for 0.5 micrometer thick sections assuming the worst possible case, namely that all heat went into the section without loss. Presence of a Type II pattern (large fracture pattern) is thought to be presumptive evidence against thawing.

  12. Dynamic laser piercing of thick section metals

    Science.gov (United States)

    Pocorni, Jetro; Powell, John; Frostevarg, Jan; Kaplan, Alexander F. H.

    2018-01-01

    Before a contour can be laser cut the laser first needs to pierce the material. The time taken to achieve piercing should be minimised to optimise productivity. One important aspect of laser piercing is the reliability of the process because industrial laser cutting machines are programmed for the minimum reliable pierce time. In this work piercing experiments were carried out in 15 mm thick stainless steel sheets, comparing a stationary laser and a laser which moves along a circular trajectory with varying processing speeds. Results show that circular piercing can decrease the pierce duration by almost half compared to stationary piercing. High speed imaging (HSI) was employed during the piercing process to understand melt behaviour inside the pierce hole. HSI videos show that circular rotation of the laser beam forces melt to eject in opposite direction of the beam movement, while in stationary piercing the melt ejects less efficiently in random directions out of the hole.

  13. A Technique for Section Thickness Evaluation for Microphotometry and Image Analysis of Sectioned Nuclei

    Directory of Open Access Journals (Sweden)

    R. L. Cabrini

    1998-01-01

    Full Text Available The exact knowledge of the section thickness is a requisite for making the necessary corrections on DNA measurements in tissue sections. Several methods have been proposed to evaluate section thickness, each of them with advantages and disadvantages depending on the type of specimen and equipment available. We herein report another method based on preparation of standard material whose optical density varies as a function of its thickness and is sectioned and measured alongside the tissue specimen. The standards consist of celloidin cylinders stained with the PAS reaction and embedded in paraffin. For prior characterization of the cylinders, sections of different thickness were obtained and mounted. The optical density of each section was measured by direct microphotometry or image analysis. The actual thickness of each section was evaluated following re-embedding of piled groups of sections in a paraffin block and transversal sectioning. The thickness was then measured with a micrometric eye-piece. Optical density and actual thickness of each section were plotted on a normogram curve. Once a given tissue is sectioned alongside with the reference cylinder, the actual thickness is determined by its optical density on the normogram curve.

  14. Economical Fabrication of Thick-Section Ceramic Matrix Composites

    Science.gov (United States)

    Babcock, Jason; Ramachandran, Gautham; Williams, Brian; Benander, Robert

    2010-01-01

    A method was developed for producing thick-section [>2 in. (approx.5 cm)], continuous fiber-reinforced ceramic matrix composites (CMCs). Ultramet-modified fiber interface coating and melt infiltration processing, developed previously for thin-section components, were used for the fabrication of CMCs that were an order of magnitude greater in thickness [up to 2.5 in. (approx.6.4 cm)]. Melt processing first involves infiltration of a fiber preform with the desired interface coating, and then with carbon to partially densify the preform. A molten refractory metal is then infiltrated and reacts with the excess carbon to form the carbide matrix without damaging the fiber reinforcement. Infiltration occurs from the inside out as the molten metal fills virtually all the available void space. Densification to coatings to the fiber preform was also required to accommodate the high preform thickness. The thick-section CMC processing developed in this work proved to be invaluable for component development, fabrication, and testing in two complementary efforts. In a project for the Army, involving SiC/SiC blisk development, nominally 0.8 in. thick x 8 in. diameter (approx. 2 cm thick x 20 cm diameter) components were successfully infiltrated. Blisk hubs were machined using diamond-embedded cutting tools and successfully spin-tested. Good ply uniformity and extremely low residual porosity (matrix composites fabricated via CVI or PIP. The pyrolytic carbon/zirconium nitride interface coating optimized in this work for use on carbon fibers was incorporated in the SiC/SiC composites and yielded a >41 ksi (approx. 283 MPa) flexural strength.

  15. DNA Measurement of Overlapping Cell Nuclei in Thick Tissue Sections

    Directory of Open Access Journals (Sweden)

    Liang Ji

    1997-01-01

    Full Text Available The paper describes an improved image analysis procedure for measuring the DNA content of cell nuclei in thick sections of liver tissue by absorption densitometry. Whereas previous methods only permitted the analysis of isolated nuclei, the new technique enables both isolated and overlapping nuclei to be measured. A 3D segmentation procedure determines whether each object is an isolated nucleus or a pair of overlapping nuclei; in the latter case the combined optical density is redistributed to the individual nuclei. A selection procedure ensures that only complete nuclei are measured.

  16. Weld repair issues in thick section austenitic pipework

    International Nuclear Information System (INIS)

    Goodwin, S.J.; Price, A.T.

    1989-03-01

    Thick section austenitic Type 316 Stainless steel, in the solution treated condition, has been used in Central Electricity Generating Board plant in the United Kingdom for some three decades and has given good service. Repair and replacement of this material after long term service is becoming a requirement and is complicated by the precipitation hardening and sensitisation of the materials. This paper summarises the compositional, microstructural and ageing characteristics of the wrought material and weld metals and the consequences for materials properties. Post weld heat treatment options are outlined and sensitisation to stress corrosion cracking is discussed. Finally, some examples of cracking that has occurred in plant after long term operation are given and weld repair research requirements are noted. (author)

  17. Practicable methods for histological section thickness measurement in quantitative stereological analyses

    Science.gov (United States)

    Matenaers, Cyrill; Popper, Bastian; Rieger, Alexandra; Wanke, Rüdiger

    2018-01-01

    The accuracy of quantitative stereological analysis tools such as the (physical) disector method substantially depends on the precise determination of the thickness of the analyzed histological sections. One conventional method for measurement of histological section thickness is to re-embed the section of interest vertically to its original section plane. The section thickness is then measured in a subsequently prepared histological section of this orthogonally re-embedded sample. However, the orthogonal re-embedding (ORE) technique is quite work- and time-intensive and may produce inaccurate section thickness measurement values due to unintentional slightly oblique (non-orthogonal) positioning of the re-embedded sample-section. Here, an improved ORE method is presented, allowing for determination of the factual section plane angle of the re-embedded section, and correction of measured section thickness values for oblique (non-orthogonal) sectioning. For this, the analyzed section is mounted flat on a foil of known thickness (calibration foil) and both the section and the calibration foil are then vertically (re-)embedded. The section angle of the re-embedded section is then calculated from the deviation of the measured section thickness of the calibration foil and its factual thickness, using basic geometry. To find a practicable, fast, and accurate alternative to ORE, the suitability of spectral reflectance (SR) measurement for determination of plastic section thicknesses was evaluated. Using a commercially available optical reflectometer (F20, Filmetrics®, USA), the thicknesses of 0.5 μm thick semi-thin Epon (glycid ether)-sections and of 1–3 μm thick plastic sections (glycolmethacrylate/ methylmethacrylate, GMA/MMA), as regularly used in physical disector analyses, could precisely be measured within few seconds. Compared to the measured section thicknesses determined by ORE, SR measures displayed less than 1% deviation. Our results prove the applicability

  18. Microstructural Analysis of Orientation-Dependent Recovery and Recrystallization in a Modified 9Cr-1Mo Steel Deformed by Compression at a High Strain Rate

    DEFF Research Database (Denmark)

    Zhang, Zhenbo; Zhang, Yubin; Mishin, Oleg

    2016-01-01

    energies in 〈111〉- and 〈100〉-oriented regions in deformed and annealed samples, as well as investigations of the growth of recrystallizing grains, are used to analyze the annealing behavior. It is concluded that recrystallization in the given material occurs by a combination of oriented nucleation...

  19. Dorsiflexor muscle-group thickness in children with cerebral palsy: Relation to cross-sectional area

    DEFF Research Database (Denmark)

    Bandholm, Thomas; Magnusson, Peter; Jensen, Bente Rona

    2009-01-01

    If the thickness and cross-sectional area of the dorsiflexor muscle group are related in children with cerebral palsy, measurements of muscle thickness may be used to monitor changes in muscle size due to training or immobilisation in these patients. We assessed the validity and reliability.......001), and the reliability of the muscle-thickness measurements was high in the healthy subjects (ICC_{2.1} = 0.94, standard error of measurement = 0.04 cm). The dorsiflexor muscle-thickness was 22% less in the affected compared to the non-affected leg in children with hemiplegic cerebral palsy (P ..., the dorsiflexor cross-sectional area was 32% less in the affected compared to the non-affected leg (P = 0.002). Measurements of dorsiflexor muscle-thickness can be reliably obtained, and they reflect dorsiflexor cross-sectional area in children with cerebral palsy....

  20. Normal bladder wall thickness measurement in healthy Iranian children, a cross-sectional study

    OpenAIRE

    Adibi, Atoosa; Kazemian, Afarin; Toghiani, Ali

    2014-01-01

    Background: Normal bladder function is necessary for micturition. Many causes such as urinary tract infection, bladder outlet obstruction, and neuropathic bladder can influence bladder wall thickness (BWT).This study was designed to determine normal BWT in Iranian children. Materials and Methods: This was a cross-sectional study done in Isfahan in 2012 comprising 82 children aged 2-14 years without any urinary complaint. We measured thickness of posterior and lateral walls of the bladder ...

  1. Modeling the curing process of thick-section autoclave cured composites

    Science.gov (United States)

    Loos, A. C.; Dara, P. H.

    1985-01-01

    Temperature gradients are significant during cure of large area, thick-section composites. Such temperature gradients result in nonuniformly cured parts with high void contents, poor ply compaction, and variations in the fiber/resin distribution. A model was developed to determine the temperature distribution in thick-section autoclave cured composites. Using the model, long with temperature measurements obtained from the thick-section composites, the effects of various processing parameters on the thermal response of the composites were examined. A one-dimensional heat transfer model was constructed for the composite-tool assembly. The governing differential equations and associated boundary conditions describing one-dimensional unsteady heat-conduction in the composite, tool plate, and pressure plate are given. Solution of the thermal model was obtained using an implicit finite difference technique.

  2. Low-energy cross section measurements through detection of secondary gamma emission and thick target

    Energy Technology Data Exchange (ETDEWEB)

    Barron P, L.; Chavez L, E.; Huerta H, A.; Ortiz, M.E. [Instituto de Fisica UNAM, A.P. 20-364, 04510 Mexico, D.F. (Mexico); Murillo O, G.; Aguilera, E.F.; Martinez Q, E.; Moreno B, E.; Policroniades R, R.; Varela G, A. [Instituto Nacional de Investigaciones Nucleares, Departamento del Acelerador, A.P. 18-1027, 11801, Mexico, D.F. (Mexico)

    2004-12-01

    In this work, the detection of secondary gamma rays in a tightly shielded Germanium detector, together with a high intensity heavy ion beam on a thick target is used to measure the fusion cross section for the {sup 12} C + {sup 12} C system at very low energies. (Author) 14 refs., 1 tab., 8 figs.

  3. Estimating the thickness of ultra thin sections for electron microscopy by image statistics

    DEFF Research Database (Denmark)

    Sporring, Jon; Khanmohammadi, Mahdieh; Darkner, Sune

    2014-01-01

    We propose a method for estimating the thickness of ultra thin histological sections by image statistics alone. Our method works for images, that are the realisations of a stationary and isotropic stochastic process, and it relies on the existence of statistical image-measures that are strictly m...

  4. Normal bladder wall thickness measurement in healthy Iranian children, a cross-sectional study

    Science.gov (United States)

    Adibi, Atoosa; Kazemian, Afarin; Toghiani, Ali

    2014-01-01

    Background: Normal bladder function is necessary for micturition. Many causes such as urinary tract infection, bladder outlet obstruction, and neuropathic bladder can influence bladder wall thickness (BWT). This study was designed to determine normal BWT in Iranian children. Materials and Methods: This was a cross-sectional study done in Isfahan in 2012 comprising 82 children aged 2-14 years without any urinary complaint. We measured thickness of posterior and lateral walls of the bladder in all children. Mean bladder wall thickness (MBWT) and mean bladder volume (BV) were also calculated. Results: In this study, we included 82 children (40 boys and 42 girls). Patients’ mean age was 6.43 ± 2.89 years, mean weight was 21.32 ± 8.40 kg, mean height was 111.57 ± 20.51 cm, and mean Body Mass Index was 17.12 ± 4.93. Mean lateral bladder wall thickness (LBWT) was 1.75 ± 0.32 mm and mean posterior bladder wall thickness (PBWT) was 1.59 ± 0.34 mm. Mean BV was 111.65 ± 72.11 ml and MBWT was 1.67 ± 0.28 mm. BVW all Index (BVWI) was 1249.05 ± 701.67. Conclusions: LBWT was1.75 ± 0.32 mm and PBWT was 1.59 ± 0.34 mm. PMID:25250302

  5. Normal bladder wall thickness measurement in healthy Iranian children, a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Atoosa Adibi

    2014-01-01

    Full Text Available Background: Normal bladder function is necessary for micturition. Many causes such as urinary tract infection, bladder outlet obstruction, and neuropathic bladder can influence bladder wall thickness (BWT.This study was designed to determine normal BWT in Iranian children. Materials and Methods: This was a cross-sectional study done in Isfahan in 2012 comprising 82 children aged 2-14 years without any urinary complaint. We measured thickness of posterior and lateral walls of the bladder in all children. Mean bladder wall thickness (MBWT and mean bladder volume (BV were also calculated. Results: In this study, we included 82 children (40 boys and 42 girls. Patients′ mean age was 6.43 ± 2.89 years, mean weight was 21.32 ± 8.40 kg, mean height was 111.57 ± 20.51 cm, and mean Body Mass Index was 17.12 ± 4.93. Mean lateral bladder wall thickness (LBWT was 1.75 ± 0.32 mm and mean posterior bladder wall thickness (PBWT was 1.59 ± 0.34 mm. Mean BV was 111.65 ± 72.11 ml and MBWT was 1.67 ± 0.28 mm. BVW all Index (BVWI was 1249.05 ± 701.67. Conclusions: LBWT was1.75 ± 0.32 mm and PBWT was 1.59 ± 0.34 mm.

  6. Influence of Casting Section Thickness on Fatigue Strength of Austempered Ductile Iron

    Science.gov (United States)

    Olawale, J. O.; Ibitoye, S. A.

    2017-10-01

    The influence of casting section thickness on fatigue strength of austempered ductile iron was investigated in this study. ASTM A536 65-45-12 grade of ductile iron was produced, machined into round samples of 10, 15, 20 and 25 mm diameter, austenitized at a temperature of 820 °C, quenched into an austempering temperature (TA) of 300 and 375 °C and allowed to be isothermally transformed at these temperatures for a fixed period of 2 h. From the samples, fatigue test specimens were machined to conform to ASTM E-466. Scanning electron microscopy (SEM) and x-ray diffraction (XRD) methods were used to characterize microstructural morphology and phase distribution of heat-treated samples. The fatigue strength decreases as the section thickness increases. The SEM image and XRD patterns show a matrix of acicular ferrite and carbon-stabilized austenite with ferrite coarsening and volume fraction of austenite reducing as the section thickness increases. The study concluded that the higher the value of carbon-stabilized austenite the higher the fatigue strength while it decreases as the ausferrite structure becomes coarse.

  7. Human Chorioretinal Layer Thicknesses Measured in Macula-wide, High-Resolution Histologic Sections

    Science.gov (United States)

    Messinger, Jeffrey D.; Sloan, Kenneth R.; Mitra, Arnab; McGwin, Gerald; Spaide, Richard F.

    2011-01-01

    Purpose. To provide a comprehensive description of chorioretinal layer thicknesses in the normal human macula, including two-layer pairs that can produce a combined signal in some optical coherence tomography (OCT) devices (ganglion cell [GCL] and inner plexiform [IPL] layers and outer plexiform [OPL] and outer nuclear [ONL] layers). Methods. In 0.8-μm-thick, macula-wide sections through the foveola of 18 donors (age range, 40–92 years), 21 layers were measured at 25 locations by a trained observer and validated by a second observer. Tissue volume changes were assessed by comparing total retinal thickness in ex vivo OCT and in sections. Results. Median tissue shrinkage was 14.5% overall and 29% in the fovea. Histologic laminar boundaries resembled those in SD-OCT scans, but the shapes of the foveolar OPL and ONL differed. Histologic GCL, IPL, and OPLHenle were thickest at 0.8. to 1, 1.5, and 0.4 mm eccentricity, respectively. ONL was thickest in an inward bulge at the foveal center. At 1 mm eccentricity, GCL, INL, and OPLHenle represented 17.3% to 21.1%, 18.0% to 18.5%, and 14.2% to 16.6% of total retinal thickness, respectively. In donors ≥70 years of age, the RPE and choroid were 17.1% and 29.6% thinner and OPLHenle was 20.8% thicker than in donors macula were generated. Newer OCT systems can separate GCL from IPL and OPLHenle from ONL, with good agreement for the proportion of retinal thickness occupied by OPLHenle in OCT and histology. The thickening of OPLHenle in older eyes may reflect Müller cell hypertrophy associated with rod loss. PMID:21421869

  8. [The structure of thick filaments on longitudinal sections of rabbit psoas muscle].

    Science.gov (United States)

    Podlubnaia, Z A; Latsabidze, I L; Lednev, V V

    1989-01-01

    By means of electron microscopy the longitudinal sections of chemically skinned fibres of rigorised rabbit psoas muscle have been examined at pH of rigorising solutions equal to 6, 7, 8 (I = 0.125) and ionic strengths equal to 0.04, 0.125, 0.34 (pH 7.0). It has been revealed that at pH 6.0 the bands of minor proteins localization in A-disks were seen very distinctly, while at pH 7.0 and I = 0.125 these bands can be revealed only by means of antibody labelling technique. At the ionic strength of 0.34 (pH 7.0) the periodicity of 14.3 nm in thick filaments was clearly observed, which was determined by packing of the myosin rods into the filament shaft and of the myosin heads (cross-bridges) on the filament surface. The number of cross-bridge rows in the filament equals 102. A new scheme of myosin cross-bridge distribution in thick filaments of rabbit psoas muscle has been suggested according to which two rows of cross-bridges at each end of a thick filament are absent. The filament length equals 1.64 +/- 0.01 micron. It has been shown that the length of thick filament as well as the structural organization of their end regions in rabbit psoas muscle and frog sartorius one are different.

  9. Usefulness of concurrent reading using thin-section and thick-section CT images in subcentimetre solitary pulmonary nodules.

    Science.gov (United States)

    Lee, H Y; Goo, J M; Lee, H J; Lee, C H; Park, C M; Park, E-A; Im, J-G

    2009-02-01

    To evaluate the differences in the characterization and recommendation for follow-up of subcentimetre solitary pulmonary nodules (SSPNs) between 5 and 1mm section CT, and to compare the assessments generated by four radiologists Five hundred and twenty-nine patients who had SSPNs on chest CT reconstructed using both 5 and 1mm sections were enrolled. Two image subsets of 5 and 1mm CT images of each nodule were interpreted independently by four radiologists. Nodule size, consistency (solid, partly solid, non-solid), the presence of calcification, and recommendations for follow-up were evaluated. If a non-calcified solid nodule was confirmed using CT, recommendation for follow-up was based on Fleischner Society guidelines. Data assessed by each radiologist were compared, and interobserver agreements were determined using the intraclass correlation coefficients and kappa value. Using 1mm CT images, the nodule sizes were significantly larger than on 5mm CT images (paired t-test, pimages (McNemar test for the presence of calcification, pimages there was significantly higher agreement regarding nodule consistency than on 5mm CT (kappa=0.78 and 0.67, respectively). Concurrent use of thin-section and thick-section CT can provide more accurate nodule assessment and higher interobserver agreement in SSPN.

  10. Fracture Toughness of Thick Boride Layers Estimated by the Cross-Sectioned Scratch Test

    Science.gov (United States)

    Campos-Silva, I.; Flores-Jiménez, M.; Bravo-Bárcenas, D.; Rodríguez-Castro, G.; Martínez-Trinidad, J.; Meneses-Amador, A.

    2018-02-01

    New results about the fracture toughness ( K c) of thick boride layers estimated by the cross-sectioned scratch test are presented in this study. The FeB-Fe2B layers developed at the surface of borided AISI 1018 and AISI 1045 steels and the Fe2B layer formed on the borided AISI 1045 steel exposed to a diffusion annealing process (DAP) were used for this purpose. The cross-sectioned scratch tests were performed with a Vickers diamond stylus drawn across the thick boride layer under a constant load to produce a half-cone-shaped fracture near to the top surface of the borided steels. The height of the half-cone-shaped fracture as a function of the cross-sectioned scratch loads was used to determine the fracture toughness of the FeB and Fe2B layers. The results showed a fracture resistance of ˜2.8 {MPa}√ m for the FeB layer formed at the surface of borided AISI 1045 steel. Likewise, the effect of the DAP on the surface of the borided AISI 1045 steel promoted the formation of an exclusively Fe2B layer, with an increase in the fracture toughness of the whole boride layer around 5 {MPa}√ m. Finally, the principle of the technique can be used to minimize the influence of the anisotropic properties on the fracture toughness along the depth of boride layers.

  11. A Thick-Sectioning Technique for Preservation of Bone-Metal Interfaces,

    Science.gov (United States)

    1986-01-01

    of the interface was easily characterized with Eosin. Microscopic evaluations of osseointegrated dental implants mau be greatlu facilitated with this...AD-RI68 525 R THICK-SECTIONING TECHNIQUE FOR PRESERVATION OF 1/1 BONE-METRL INTERFACES(U) ARMY INST OF DENTAL RESEARCH NASHINGTON DC J MIZGRLR ET RL...Institute of Dental Research Walter Read Armu Medical Center >n Washington, DC 20307-5300 LLJ C.,*Address for reprints DSII fIO IrTEEII IApproved for? Public

  12. Synthetic aperture focusing technique in real-time and tandem operation for thick section steels

    International Nuclear Information System (INIS)

    Doctor, S.R.; Hall, T.E.; Reid, L.D.; Mart, G.A.

    1988-01-01

    The authors report on a program underway at Pacific Northwest Laboratory (PNL) to move the synthetic aperture focusing technique (SAFT) from the laboratory into the field for the purpose of inspecting light-water reactor (LWR) components. The SAFT technology was developed to produce high-resolution and high signal-to-noise ratio images of ultrasonic anomalies in materials. Other researchers have been involved in developing the 2-D or line SAFT technology, but the one thing that has limited the acceptance of 38-D SAFT is the slow processing rates. This paper describes how a special purpose processor can be used to achieve processing rates of 10 A-scans/second or larger. The tandem mode has been successfully used with SAFT but only on this materials. This paper also describes how to effectively implement the tandem mode for thick section materials

  13. Diagnosis of bronchiectasis with multislice spiral CT: accuracy of 3-mm-thick structured sections

    Energy Technology Data Exchange (ETDEWEB)

    Remy-Jardin, Martine; Amara, Assia; Campistron, Philippe; Mastora, Ioana; Remy, Jacques [Department of Radiology, Hospital Calmette, University Center of Lille, Boulevard Jules Leclerc, 59037, Lille Cedex (France); Delannoy, Valerie; Duhamel, Alain [Department of Medical Statistics, University of Lille, Place de Verdun, 59037, Lille Cedex (France)

    2003-05-01

    The aim of this study was to evaluate the accuracy of 3-mm-thick reconstructed sections in the diagnosis of bronchiectasis with multislice CT (MSCT). Forty consecutive patients suspected of bronchiectasis (23 females, 17 males; mean age 51 years) underwent MSCT of the entire thorax with a 4 x 1-mm collimation (120 kV, 0.5 s/rotation, 80 mAs/slice) and a pitch of 1.75. From each data set (mean z-axis coverage: 257 mm; mean duration: 21 s), two series of images were systematically generated: 1-mm (group 1) and 3-mm (group 2)-thick reconstructed scans. Both series of images were obtained at 10-mm intervals and reconstructed with a high-spatial-frequency algorithm. Two observers independently analyzed the presence of bronchiectasis and associated abnormalities in group-1 and group-2 lung images. No significant difference between group 1 and group 2 was found in: (a) the detection of bronchiectasis, identified in 24 patients (60%) in group 1 and in 23 patients (57.5%) in group 2 (p=0.08); (b) the evaluation of the extent of bronchiectasis, identifying focal bronchiectasis in 10 patients (25%) in group 1 and 7 patients (17.5%) in group 2 (p=0.39) and multifocal bronchiectasis in 16 patients (40%) in both groups; (c) the characterisation of bronchiectasis (cylindral bronchiectasis: group 1, n=24, 60%; group 2, n=21, 53%, p=0.08); varicose bronchiectasis: group 1, n=5, 12.5%; group 2, n=6, 15%, p=0.56; and cystic bronchiectasis: group 1, n=2, 5%; group 2, n=2, 5%. Apart from the identification of abnormal bronchial wall thickening (group 2, n=35, 87.5%, vs group 1, n=31, 77.5%, p<0.05), recognition of associated bronchopulmonary anomalies did not differ between the two groups. This study demonstrates a comparable accuracy of the 3- and 1-mm-thick reconstructed scans in the detection and characterization of bronchiectasis. These results suggest the potential usefulness of 3-mm-thick scans generated from 4 x 2.5-mm acquisitions in the screening of bronchiectasis, which would

  14. Effect of Filtration and Thickness of Cross-Sections of Cone Beam Computed Tomography Images on Detection of Proximal Caries.

    Science.gov (United States)

    Abdinian, Mehrdad; Nazeri, Rahman; Ghaiour, Marzieh

    2017-07-01

    When a patient has cone beam computed tomography (CBCT) images based on the treatment plan, it is possible to use these images for evaluation of caries, and there is no need for new radiographs, according to the "as low as reasonably achievable" (ALARA) principle. The aim of this study was to determine the effect of filtration and thickness of CBCT cross-sections on detection of proximal caries. In this in-vitro study, 100 teeth were placed in the dental sockets of a dry skull, and were fixed in normal proximal contacts. CBCT images were taken and were evaluated by two observers on the panoramic view at 1-, 3- and 5-mm-thick cross-sections, with the use of filtrations 0, 1 and 2. Afterwards, the samples were sectioned and underwent a histological evaluation. McNemar's test was used to compare the findings on CBCT images and histological evaluation. Receiver operating characteristic (ROC) curves and logistic regression were used to evaluate the diagnostic accuracy of different cross-sections. The maximum AZ-value was achieved at 3-mm thickness/filtration 2. However, the differences between 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1 were not significant (P=0.728 and 0.868, respectively). The minimum AZ-value was achieved at 5-mm thickness/filtration 0. Although CBCT is not sufficiently effective in detecting caries, the best cross-sections for detection of proximal caries were achieved at 3-mm thickness/filtration 2, 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1.

  15. Effect of Filtration and Thickness of Cross-Sections of Cone Beam Computed Tomography Images on Detection of Proximal Caries

    Directory of Open Access Journals (Sweden)

    Mehrdad Abdinian

    2017-10-01

    Full Text Available Objectives: When a patient has cone beam computed tomography (CBCT images based on the treatment plan, it is possible to use these images for evaluation of caries, and there is no need for new radiographs, according to the "as low as reasonably achievable" (ALARA principle. The aim of this study was to determine the effect of filtration and thickness of CBCT cross-sections on detection of proximal caries.Materials and Methods: In this in-vitro study, 100 teeth were placed in the dental sockets of a dry skull, and were fixed in normal proximal contacts. CBCT images were taken and were evaluated by two observers on the panoramic view at 1-, 3- and 5-mm-thick cross-sections, with the use of filtrations 0, 1 and 2. Afterwards, the samples were sectioned and underwent a histological evaluation. McNemar’s test was used to compare the findings on CBCT images and histological evaluation. Receiver operating characteristic (ROC curves and logistic regression were used to evaluate the diagnostic accuracy of different cross-sections.Results: The maximum AZ-value was achieved at 3-mm thickness/filtration 2. However, the differences between 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1 were not significant (P=0.728 and 0.868, respectively. The minimum AZ-value was achieved at 5-mm thickness/filtration 0.Conclusions: Although CBCT is not sufficiently effective in detecting caries, the best cross-sections for detection of proximal caries were achieved at 3-mm thickness/filtration 2, 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1.

  16. Optical histology: a method to visualize microvasculature in thick tissue sections of mouse brain.

    Directory of Open Access Journals (Sweden)

    Austin J Moy

    Full Text Available The microvasculature is the network of blood vessels involved in delivering nutrients and gases necessary for tissue survival. Study of the microvasculature often involves immunohistological methods. While useful for visualizing microvasculature at the µm scale in specific regions of interest, immunohistology is not well suited to visualize the global microvascular architecture in an organ. Hence, use of immunohistology precludes visualization of the entire microvasculature of an organ, and thus impedes study of global changes in the microvasculature that occur in concert with changes in tissue due to various disease states. Therefore, there is a critical need for a simple, relatively rapid technique that will facilitate visualization of the microvascular network of an entire tissue.The systemic vasculature of a mouse is stained with the fluorescent lipophilic dye DiI using a method called "vessel painting". The brain, or other organ of interest, is harvested and fixed in 4% paraformaldehyde. The organ is then sliced into 1 mm sections and optically cleared, or made transparent, using FocusClear, a proprietary optical clearing agent. After optical clearing, the DiI-labeled tissue microvasculature is imaged using confocal fluorescence microscopy and adjacent image stacks tiled together to produce a depth-encoded map of the microvasculature in the tissue slice. We demonstrated that the use of optical clearing enhances both the tissue imaging depth and the estimate of the vascular density. Using our "optical histology" technique, we visualized microvasculature in the mouse brain to a depth of 850 µm.Presented here are maps of the microvasculature in 1 mm thick slices of mouse brain. Using combined optical clearing and optical imaging techniques, we devised a methodology to enhance the visualization of the microvasculature in thick tissues. We believe this technique could potentially be used to generate a three-dimensional map of the

  17. Greater Cortical Thickness in Elderly Female Yoga Practitioners—A Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Rui F. Afonso

    2017-06-01

    Full Text Available Yoga, a mind-body activity that requires attentional engagement, has been associated with positive changes in brain structure and function, especially in areas related to awareness, attention, executive functions and memory. Normal aging, on the other hand, has also been associated with structural and functional brain changes, but these generally involve decreased cognitive functions. The aim of this cross-sectional study was to compare brain cortical thickness (CT in elderly yoga practitioners and a group of age-matched healthy non-practitioners. We tested 21 older women who had practiced hatha yoga for at least 8 years and 21 women naive to yoga, meditation or any mind-body interventions who were matched to the first group in age, years of formal education and physical activity level. A T1-weighted MPRAGE sequence was acquired for each participant. Yoga practitioners showed significantly greater CT in a left prefrontal lobe cluster, which included portions of the lateral middle frontal gyrus, anterior superior frontal gyrus and dorsal superior frontal gyrus. We found greater CT in the left prefrontal cortex of healthy elderly women who trained yoga for a minimum of 8 years compared with women in the control group.

  18. Carotid intima-media thickness and osteoporosis in postmenopausal women: a cross-sectional study.

    Science.gov (United States)

    Sothornwit, J; Somboonporn, W; Soontrapa, S; Kaewrudee, S; Wongwiwatchai, J; Soontrapa, S

    2018-03-09

    To explore the difference in carotid intima-media thickness (CIMT) between postmenopausal women with and without osteoporosis and the risk of elevated CIMT and plaque presentation. A cross-sectional study was conducted including 46 postmenopausal women with osteoporosis and 45 non-osteoporotic postmenopausal women. CIMT was measured using B-mode ultrasound. There was no statistically significant difference in mean CIMT between postmenopausal women with osteoporosis and those without osteoporosis (p > 0.05). Risk for elevated CIMT in the osteoporosis group was comparable to that of the non-osteoporosis group (adjusted odds ratio = 0.844; 95% confidence interval 0.11-6.45). The risk for the presence of plaque was three times higher in osteoporotic women than in normal individuals. However, after adjusting for age and underlying diseases that would predispose the women to cardiovascular disease, there was no significant difference in terms of presence of plaque between the two groups (adjusted odds ratio = 0.844; 95% confidence interval 0.11-6.45). There was no difference in mean CIMT between postmenopausal women with and without osteoporosis. Risk of elevated CIMT in postmenopausal women with osteoporosis was comparable to that of postmenopausal women without osteoporosis. There was no significant difference between the two groups in terms of the presence of plaque.

  19. Age effects on cortical thickness in young Down's syndrome subjects: a cross-sectional gender study

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Andrea; Moraschi, Marta [San Raffaele Foundation Rome, Rehabilitation Facility Ceglie Messapica, Rome (Italy); Cornia, Riccardo; Stella, Giacomo [University of Modena and Reggio Emilia, Department of Education and Human Sciences, Emilia-Romagna (Italy); Bozzao, Alessandro; Gagliardo, Olga [University Sapienza, NESMOS, Department of Neuroradiology, S. Andrea Hospital, Rome (Italy); Chiacchiararelli, Laura [University Sapienza, Department of Medical Physics, S. Andrea Hospital, Rome (Italy); Iani, Cristina [University of Modena and Reggio Emilia, Department of Communication and Economy, Emilia-Romagna (Italy); Albertini, Giorgio [IRCSS San Raffaele Pisana, Department of Paediatrics, Rome (Italy); Pierallini, Alberto [IRCSS San Raffaele Pisana, Department of Radiology, Rome (Italy)

    2015-04-01

    The aim of this study was to determine differences in the characteristic pattern of age-related cortical thinning in men and women with Down's syndrome (DS) by means of MRI and automatic cortical thickness measurements and a cross-sectional design, in a large cohort of young subjects. Eighty-four subjects with DS, 30 females (11-35 years, mean age ± SD = 22.8 ± 5.9) and 54 males (11-35 years, mean age ± SD = 21.5 ± 6.5), were examined using a 1.5-T scanner. MRI-based quantification of cortical thickness was performed using FreeSurfer software package. For all subjects participating in the study, the Pearson product-moment correlation coefficient between age and mean cortical thickness values has been evaluated. A significant negative correlation between cortical thickness and age was found in female DS subjects, predominantly in frontal and parietal lobes, bilaterally. In male DS subjects, a significant negative correlation between cortical thickness and age was found in the right fronto-temporal lobes and cingulate regions. Whole brain mean cortical thickness values were significantly negative correlated with age only in female DS subjects. Females with Down's syndrome showed a strong correlation between cortical thickness and age, already in early age. We suggest that the cognitive impairment due to hormonal deficit in the postmenopausal period could be emphasized by the early structural decline of gray matter in female DS subjects. (orig.)

  20. Age effects on cortical thickness in young Down's syndrome subjects: a cross-sectional gender study

    International Nuclear Information System (INIS)

    Romano, Andrea; Moraschi, Marta; Cornia, Riccardo; Stella, Giacomo; Bozzao, Alessandro; Gagliardo, Olga; Chiacchiararelli, Laura; Iani, Cristina; Albertini, Giorgio; Pierallini, Alberto

    2015-01-01

    The aim of this study was to determine differences in the characteristic pattern of age-related cortical thinning in men and women with Down's syndrome (DS) by means of MRI and automatic cortical thickness measurements and a cross-sectional design, in a large cohort of young subjects. Eighty-four subjects with DS, 30 females (11-35 years, mean age ± SD = 22.8 ± 5.9) and 54 males (11-35 years, mean age ± SD = 21.5 ± 6.5), were examined using a 1.5-T scanner. MRI-based quantification of cortical thickness was performed using FreeSurfer software package. For all subjects participating in the study, the Pearson product-moment correlation coefficient between age and mean cortical thickness values has been evaluated. A significant negative correlation between cortical thickness and age was found in female DS subjects, predominantly in frontal and parietal lobes, bilaterally. In male DS subjects, a significant negative correlation between cortical thickness and age was found in the right fronto-temporal lobes and cingulate regions. Whole brain mean cortical thickness values were significantly negative correlated with age only in female DS subjects. Females with Down's syndrome showed a strong correlation between cortical thickness and age, already in early age. We suggest that the cognitive impairment due to hormonal deficit in the postmenopausal period could be emphasized by the early structural decline of gray matter in female DS subjects. (orig.)

  1. Imaging Drosophila brain by combining cryo-soft X-ray microscopy of thick vitreous sections and cryo-electron microscopy of ultrathin vitreous sections.

    Science.gov (United States)

    Leforestier, Amélie; Levitz, Pierre; Preat, Thomas; Guttmann, Peter; Michot, Laurent J; Tchénio, Paul

    2014-11-01

    Cryo-soft X-ray microscopy is an emerging imaging tool complementary to cryo-electron microscopy, allowing to image frozen hydrated specimens ten to hundred times thicker, but at lower resolution. We describe how the method, so far restricted to isolated small cells or cell monolayers, can be extended to large cells and tissue. We image the synapses of the Kenyon cells in frozen hydrated Drosophila brains combining cryo-soft X-ray microscopy of thick vitreous sections, and cryo-electron microscopy of ultrathin vitreous sections. We show how to obtain frozen hydrated sections of thicknesses ranging from 40 nm up to 2.5 μm, by tuning the sectioning speed of the cryo-microtome. A fluorescent stereo-microscope mounted on the cryo-microtome allowed us to target the regions of interest after GFP-labeling of synapses. Thick cryo-sections were imaged by cryo-soft X-ray microscopy at a resolution better than 25 nm, while ultrathin cryo-sections of the same regions were explored in parallel at the nanometre level of resolution by cryo-electron microscopy. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Utilization of ultrasonic tomography for the mapping of residual stress fields in thick metal sections. Final report

    International Nuclear Information System (INIS)

    Hildebrand, B.P.; Hufferd, D.E.

    1977-01-01

    It is well known that the velocity of sound propagation through a solid is altered when a stress is applied. The velocity change is small, and dependent upon the type of wave being propagated as well as the magnitude of the stress. Sensitivity is greatest to shear wave sound with the polarization vector parallel to the direction of stress. In this case, velocity changes as great as 0.6 percent were measured. Preliminary work is described aimed at evaluating computerized reconstruction of velocity fields from velocity profiles to map residual stress concentrations in thick metal sections. Experimental results with liquid and solid models are described. One could image velocity anomalies of 0.2 percent and estimate that 0.05 percent is technically feasible. It is concluded that this technique has great potential for finding and mapping residual stress in thick metal sections

  3. Optical Sectioning and High Resolution in Single-Slice Structured Illumination Microscopy by Thick Slice Blind-SIM Reconstruction.

    Directory of Open Access Journals (Sweden)

    Aurélie Jost

    Full Text Available The microscope image of a thick fluorescent sample taken at a given focal plane is plagued by out-of-focus fluorescence and diffraction limited resolution. In this work, we show that a single slice of Structured Illumination Microscopy (two or three beam SIM data can be processed to provide an image exhibiting tight sectioning and high transverse resolution. Our reconstruction algorithm is adapted from the blind-SIM technique which requires very little knowledge of the illumination patterns. It is thus able to deal with illumination distortions induced by the sample or illumination optics. We named this new algorithm thick slice blind-SIM because it models a three-dimensional sample even though only a single two-dimensional plane of focus was measured.

  4. Development of low-cost welding procedures for thick sections of HY-150 steel

    Science.gov (United States)

    Schmidt, P. M.; Snow, R. S.

    1972-01-01

    Low cost welding procedures were developed for welding 6-inch thick HY-150 steel to be used in the manufacture of large diameter motor case Y rings and nozzle attachment flanges. An extensive investigation was made of the mechanical and metallurgical properties and fracture toughness of HY-150 base plate and welds made with manual shielded metal arc process and semi-automatic gas metal arc process in the flat position. Transverse tensiles, all-weld metal tensiles, Charpy V-notch specimens and edge notched bend specimens were tested in the course of the program. In addition metallographic studies and hardness tests were performed on the weld, weld HAZ and base metal. The results of the work performed indicate that both the shielded metal arc and gas metal arc processes are capable of producing consistently sound welds as determined by radiographic and ultrasonic inspection. In addition, the weld metal, deposited by each process was found to exhibit a good combination of strength and toughness such that the selection of a rolled and welded procedure for fabricating rocket motor case components would appear to be technically feasible.

  5. Obtention of differential sections in nuclear reactions using a thick target

    International Nuclear Information System (INIS)

    Chavez R, R.

    2000-01-01

    The nuclear reaction analysis (NRA) technique is used mainly for detecting the presence and concentration of light elements of great importance such as: carbon, nitrogen and oxygen. This work has the objective to obtain the differential sections of 16 O and 14 N starting from the irradiation with deuterons of TiSrO 3 samples, of AIN and AIN 2 at energies of 2000 KeV and 1800 KeV respectively. The present work have four chapters; chapter 1 is focused to the physical aspects which takes part in the NRA technique. The technical requirements as well as the necessary equipment for developing the techniques are described in the chapter 2. In chapter 3 it is described the algorithm developed for to obtain the differential sections starting from experimental data, and finally, in chapter 4 are given the results and conclusions. (Author)

  6. Joining Thick Section Aluminum to Steel with Suppressed FeAl Intermetallic Formation via Friction Stir Dovetailing

    Energy Technology Data Exchange (ETDEWEB)

    Reza E Rabby, MD; Ross, Kenneth A.; Overman, Nicole R.; Olszta, Matthew J.; Mcdonnell, Martin; Whalen, Scott A.

    2018-04-17

    A new solid-phase technique called friction stir dovetailing (FSD) has been developed for joining thick section aluminum to steel. In FSD, mechanical interlocks are formed at the aluminum-steel interface and are reinforced by metallurgical bonds where intermetallic growth has been uniquely suppressed. Lap shear testing shows superior strength and extension at failure compared to popular friction stir approaches where metallurgical bonding is the only joining mechanism. High resolution microscopy revealed the presence of a 40-70 nm interlayer having a composition of 76.4 at% Al, 18.4 at% Fe, and 5.2 at% Si, suggestive of limited FeAl3 intermetallic formation.

  7. High resolution ice thickness, bed topography, and roughness of a land terminating section of the western Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Lindback, K.; Pettersson, R.; Doyle, S. H.

    We present ice thickness and bed topography maps with high spatial resolution (250-500 m) of a large land terminating section of the western Greenland Ice Sheet. The maps cover the Isunnguata Sermia, Russell, and Leverett outlet glaciers and their catchment areas up to an elevation of ~1,700 m...... above sea level. The bed topography shows an intricate subglacial trough system, resembling the landscape in the proglacial area. We also calculate the hydraulic potential to get a proxy of the subglacial routing of water in the area. To analyse the geomorphological conditions of the bed, we calculated...... velocities also coincide with an overdeepened trough system in the northern parts of the area; an area where active smoothing could be taking place. The southern parts consist of high bed elevations and have generally high roughness values; the bedrock likely consists of hard unreworked orthogneiss...

  8. High-resolution ice thickness and bed topography of a land-terminating section of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Lindbäck, K.; Pettersson, R.; Doyle, S. H.

    2014-01-01

    . The covered area is one of the most studied regions of the Greenland Ice Sheet with studies of mass balance, dynamics, and supraglacial lakes, and our combined dataset can be valuable for detailed studies of ice sheet dynamics and hydrology. The compiled datasets of ground-based and airborne radar surveys......We present ice thickness and bed topography maps with high spatial resolution (250 to 500 m) of a and-terminating section of the Greenland Ice Sheet derived from combined ground-based and airborne radar surveys. The data have a total area of ~12000 km2 and cover the whole ablation area...... of the outlet glaciers of Isunnguata Sermia, Russell, Leverett, Ørkendalen and Isorlersuup up to the long-term mass balance equilibrium line altitude at ~1600 m above sea level. The bed topography shows highly variable subglacial trough systems, and the trough of the Isunnguata Sermia Glacier is over...

  9. Thick-target method in the measurement of inner-shell ionization cross-sections by low-energy electron impact

    International Nuclear Information System (INIS)

    An, Z.; Wu, Y.; Liu, M.T.; Duan, Y.M.; Tang, C.H.

    2006-01-01

    In this paper, we have studied the thick-target method for the measurements of atomic inner-shell ionization cross-section or X-ray production cross-section by keV electron impact. We find that in the processes of electron impact on the thick targets, the ratios of the characteristic X-ray yields of photoelectric ionization by bremsstrahlung to the total characteristic X-ray yields are Z-dependent and shell-dependent, and the ratios also show the weak energy-dependence. In addition, in the lower incident energy region (i.e. U < 5-6), the contribution from the rediffusion effect and the secondary electrons can be negligible. In general, the thick-target method can be appropriately applied to the measurements of atomic inner-shell ionization cross-sections or X-ray production cross-sections by electron impact for low and medium Z elements in the lower incident electron energy (i.e. U < 5-6). The experimental accuracies by the thick-target method can reach to the level equivalent or superior to the accuracies of experimental data based on the thin-target method. This thick-target method has been applied to the measurement of K-shell ionization cross-sections of Ni element by electron impact in this paper

  10. COMPARISON OF RNFL THICKNESS AND VISUAL FIELD CHANGES BETWEEN DIABETIC WITHOUT RETINOPATHY AND NONDIABETIC CONTROLS- A CROSS-SECTIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Soumya Swarup Chattopadhyay

    2017-10-01

    Full Text Available BACKGROUND Diabetes mellitus is one of the major component of metabolic syndrome and a leading cause of ocular morbidity in modern era and India will be considered to be the diabetes capital of the world. Before the onset of diabetic retinopathy, other structural and functional changes may predict the visual diminution of the individual. MATERIALS AND METHODS In this cross-sectional study in a tertiary care hospital, after inclusion and exclusion, the age-gender matched groups (diagnosed type 2 diabetes patients without diabetic retinopathy and controls without diabetes were thoroughly examined clinically and by noninvasive and invasive examination (after proper counselling of the patient and informed consent. Then, they are tested for functional loss of retina by Humphrey FDT, GDx VCC. Comparison done between cases and controls as well as poorly-controlled and well-controlled diabetic groups. RESULTS It was found that the average RNFL thickness was significantly reduced in diabetics (mean 53.48, SD 2.69 compared to controls (mean 60.21, SD 1.87 (p7%, the RNFL thickness was significantly reduced (mean 52.23, SD 1.31 compared to diabetics with good metabolic control (mean 56.38, SD 2.92 (p<0.05. In retinal functional testing, it was found that the Humphrey FDT mean deviation (FDT MD and pattern standard deviation (FDT PSD were significantly worse in diabetics (FDT MD- 1.478, SD 0.386, (FDT PSD- 3.485, SD 0.403 compared to normal controls (FDT MD- 0.442, SD 0.536, (FDT PSD- 1.438, SD 0.404. The parameters were also found to be significantly worse in uncontrolled diabetics (p<0.05. CONCLUSION To conclude, without diabetic retinopathy, functional and structural loss in retina in diabetes patients compared to age-sex matched individual and especially in poorly-controlled diabetes should be of concern as there are no detectable vasculopathy. So, early diagnosis and control of diabetes is advocated to control this functional loss

  11. Building on knowledge base of sodium cooled fast breeder reactors to develop materials technology for fusion reactors

    International Nuclear Information System (INIS)

    Raj, B.; Rao, B.S.

    2007-01-01

    Full text of publication follows: There are strong synergies between fission and fusion research. Similarities extend to candidate structural materials, methods of theoretical and experimental investigations, high operating temperatures, fast neutron exposure and similar underlying physical phenomena. Enhancing the cross-fertilization of fission and fusion R and D programmes would mutually benefit the development of both kinds of nuclear reactors for sustainable nuclear energy. Materials used in fusion energy systems must be fully code qualified for high-temperature applications that include creep, low cycle fatigue, thermo-mechanical fatigue and creep-fatigue interaction. Evaluation of various mechanical properties of reduced activation ferritic-martensitic alloys are underway for establishing reliable data bases for development of a suitable code and further optimization and redesign of the alloys for fusion reactor components. The alloys 316L (N) and derived variants of Mod.9Cr1Mo steel are anticipated for use in fusion systems and the RCC-MR code would serve as a backbone for the initial design of various components. In this respect, the efforts made in India for developing these materials, their characterization and applicability of RCC-MR code are highlighted. The salient features of consortium approach and the experience that has led to manufacturing of main and safety vessel components from 316L (N) with close dimensional tolerances, thick section forged components and seamless tubes of Modified 9Cr-1Mo steel for steam generators will be presented. The finite element analysis has been used for optimal design of die and punch for the near net shape forming of petals of main vessel of PFBR. The safe temperature and strain rate domains were established using dynamic materials model for forming of 316L (N) and 9Cr1Mo steels by various industrial processes. Welds are weak links in the design of both fission and fusion systems. Detailed investigations have led to

  12. Rotational Augmentation on a 2.3 MW Rotor Blade with Thick Flatback Airfoil Cross-Sections: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Schreck, S.; Fingersh, L.; Siegel, K.; Singh, M.; Medina, P.

    2013-01-01

    Rotational augmentation was analyzed for a 2.3 MW wind turbine, which was equipped with thick flatback airfoils at inboard radial locations and extensively instrumented for acquisition of time varying surface pressures. Mean aerodynamic force and surface pressure data were extracted from an extensive field test database, subject to stringent criteria for wind inflow and turbine operating conditions. Analyses of these data showed pronounced amplification of aerodynamic forces and significant enhancements to surface pressures in response to rotational influences, relative to two-dimensional, stationary conditions. Rotational augmentation occurrence and intensity in the current effort was found to be consistent with that observed in previous research. Notably, elevated airfoil thickness and flatback design did not impede rotational augmentation.

  13. Relationship between intima-media thickness and bone mineral density in postmenopausal women: a cross-sectional study.

    Science.gov (United States)

    Mohammadi, Afshin; Shateri, Kamran; Behzadi, Farhad; Maleki-Miandoab, Tooraj; Lesha, Emal; Ghasemi-Rad, Mohammad; Rosta, Yousef

    2014-01-01

    Osteoporosis and atherosclerosis are two conditions that confer the major cause of mortality and morbidity in postmenopausal women. Several studies have suggested that these two conditions are negatively correlated by a common pathway. The aim of our study was to show a relationship between bone mineral density (BMD) and carotid intima media thickness (CIMT), as two factors that are directly related to osteoporosis and atherosclerosis respectively. The study group consisted of 136 postmenopausal women that presented at the Radiology Clinic of our hospital for BMD measurements. The CIMT was measured using High Resolution B mode Ultrasonography; BMD was measured at the lumbar spine and femoral neck using Dual-energy X-Ray Absorptiometry. The mean IMT value in osteoporotic women (0.7±0.1 mm) was significantly higher compared to non-osteoporotic women (0.6±0.1 mm, P media thickness are negatively correlated, thus showing a possible relationship between osteoporosis and atherosclerosis. However, more research is necessary to determine the pathway that connects these two conditions.

  14. Cross section of α-induced reactions on iridium isotopes obtained from thick target yield measurement for the astrophysical γ process

    Science.gov (United States)

    Szücs, T.; Kiss, G. G.; Gyürky, Gy.; Halász, Z.; Fülöp, Zs.; Rauscher, T.

    2018-01-01

    The stellar reaction rates of radiative α-capture reactions on heavy isotopes are of crucial importance for the γ process network calculations. These rates are usually derived from statistical model calculations, which need to be validated, but the experimental database is very scarce. This paper presents the results of α-induced reaction cross section measurements on iridium isotopes carried out at first close to the astrophysically relevant energy region. Thick target yields of 191Ir(α,γ)195Au, 191Ir(α,n)194Au, 193Ir(α,n)196mAu, 193Ir(α,n)196Au reactions have been measured with the activation technique between Eα = 13.4 MeV and 17 MeV. For the first time the thick target yield was determined with X-ray counting. This led to a previously unprecedented sensitivity. From the measured thick target yields, reaction cross sections are derived and compared with statistical model calculations. The recently suggested energy-dependent modification of the α + nucleus optical potential gives a good description of the experimental data.

  15. Cross section of α-induced reactions on iridium isotopes obtained from thick target yield measurement for the astrophysical γ process

    Directory of Open Access Journals (Sweden)

    T. Szücs

    2018-01-01

    Full Text Available The stellar reaction rates of radiative α-capture reactions on heavy isotopes are of crucial importance for the γ process network calculations. These rates are usually derived from statistical model calculations, which need to be validated, but the experimental database is very scarce. This paper presents the results of α-induced reaction cross section measurements on iridium isotopes carried out at first close to the astrophysically relevant energy region. Thick target yields of 191Ir(α,γ195Au, 191Ir(α,n194Au, 193Ir(α,n196mAu, 193Ir(α,n196Au reactions have been measured with the activation technique between Eα=13.4 MeV and 17 MeV. For the first time the thick target yield was determined with X-ray counting. This led to a previously unprecedented sensitivity. From the measured thick target yields, reaction cross sections are derived and compared with statistical model calculations. The recently suggested energy-dependent modification of the α+nucleus optical potential gives a good description of the experimental data.

  16. High thickness histological sections as alternative to study the three-dimensional microscopic human sub-cortical neuroanatomy.

    Science.gov (United States)

    Alho, Eduardo Joaquim Lopes; Alho, Ana Tereza Di Lorenzo; Grinberg, Lea; Amaro, Edson; Dos Santos, Gláucia Aparecida Bento; da Silva, Rafael Emídio; Neves, Ricardo Caires; Alegro, Maryana; Coelho, Daniel Boari; Teixeira, Manoel Jacobsen; Fonoff, Erich Talamoni; Heinsen, Helmut

    2017-11-01

    Stereotaxy is based on the precise image-guided spatial localization of targets within the human brain. Even with the recent advances in MRI technology, histological examination renders different (and complementary) information of the nervous tissue. Although several maps have been selected as a basis for correlating imaging results with the anatomical locations of sub-cortical structures, technical limitations interfere in a point-to-point correlation between imaging and anatomy due to the lack of precise correction for post-mortem tissue deformations caused by tissue fixation and processing. We present an alternative method to parcellate human brain cytoarchitectural regions, minimizing deformations caused by post-mortem and tissue-processing artifacts and enhancing segmentation by means of modified high thickness histological techniques and registration with MRI of the same specimen and into MNI space (ICBM152). A three-dimensional (3D) histological atlas of the human thalamus, basal ganglia, and basal forebrain cholinergic system is displayed. Structure's segmentations were performed in high-resolution dark-field and light-field microscopy. Bidimensional non-linear registration of the histological slices was followed by 3D registration with in situ MRI of the same subject. Manual and automated registration procedures were adopted and compared. To evaluate the quality of the registration procedures, Dice similarity coefficient and normalized weighted spectral distance were calculated and the results indicate good overlap between registered volumes and a small shape difference between them in both manual and automated registration methods. High thickness high-resolution histological slices in combination with registration to in situ MRI of the same subject provide an effective alternative method to study nuclear boundaries in the human brain, enhancing segmentation and demanding less resources and time for tissue processing than traditional methods.

  17. Thick-target-method study of Mα β x-ray production cross sections of Pb and Bi impacted by positrons up to 9 keV

    Science.gov (United States)

    Wu, Y.; Liang, Y.; Xu, M. X.; Yuan, Y.; Chang, C. H.; Qian, Z. C.; Wang, B. Y.; Kuang, P.; Zhang, P.

    2018-03-01

    Atomic M -shell x-ray production cross sections induced by positrons near the threshold energy have been presented in this paper. In the experiment, online monitoring technology, which utilizes a high-purity germanium detector to record the annihilation photons emitted from the pure thick target impacted by positrons, was developed to obtain the accurate number of the incident positrons. The effects of the multiple scattering of incident positrons, from the bremsstrahlung and annihilation photons and other secondary particles on the experimental characteristic x-ray yield, were eliminated by Monte Carlo simulation in combination with theoretical integral calculation. The Tikhonov regularization method was adopted to handle the ill-posed inverse problem involved in the thick-target method, i.e., x-ray production cross sections by the corrected characteristic x-ray yield. Experimental results of Mα β x-ray production cross sections for Pb and Bi impacted by 6-9-keV positrons were compared with the corresponding values predicted by the distorted-wave Born approximation (DWBA). Good agreement was found between the two. Moreover, we have presented the experimental results on the ratios of the Mα β x-ray production cross sections by electron impact in the literature to that by 6-9-keV positron impact in this work. They were also in accordance with the theoretical ratios calculated by the predictions of DWBA theory.

  18. The Cutting of Ultrathin Sections With the Thickness Less Than 20 nm From Biological Specimens Embedded in Resin Blocks

    Czech Academy of Sciences Publication Activity Database

    Nebesářová, Jana; Hozák, Pavel; Frank, Luděk; Štěpan, P.; Vancová, Marie

    2016-01-01

    Roč. 79, č. 6 (2016), s. 512-517 ISSN 1059-910X R&D Projects: GA TA ČR(CZ) TE01020118 Institutional support: RVO:60077344 ; RVO:68378050 ; RVO:68081731 Keywords : low voltage electron microscopy * resin embedding * ultramicrotomy * ultrathin sectioning Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.147, year: 2016

  19. [Lower uterine segment thickness measurement in pregnant women with previous caesarean section: intra- and interobserver reliability analysis using bi- and tridimensional ultrasonography].

    Science.gov (United States)

    Barra, Daniela de Abreu; Martins, Wellington de Paula; Gallarretta, Francisco Maximilliano; Nastri, Carolina Oliveira; Nicolau, Luis Guilherme; Mauad Filho, Francisco

    2008-03-01

    to compare the intra and interobserver reproducibility of the total thickness measurement of the inferior uterine segment (IUS), through the abdominal route, and of the muscle layer measurement, through the vaginal route, using bi and tridimensional ultrasonography. the IUS thickness measurement of 30 women, between the 36th and 39th weeks of gestation with previous caesarean section, done by two observers, was studied. Abdominal ultrasonography with the patient in both supine and lithotomy position was performed. In the sagittal section, the IUS was identified and four bidimensional images and two tridimensional blocks of the total thickness were collected through the abdominal route, and the same for the muscle layer, through the vaginal route. Tridimensional acquisitions were manipulated in the multiplanar mode. The time was measured with a chronometer. Reproducibility was evaluated by the computation of the absolute difference between measurements, the ratio of differences smaller than 1 mm, the intraclass coefficient (ICC), and the Bland and Altman's concordance limits. the average bidimensional measurement of IUS thickness was 7.4 mm through the abdominal and 2.7 mm through the vaginal route, and the tridimensional measurement was 6.9 mm through the abdominal and 5.1 mm through the vaginal route. Intra- and interobserver reproducibility of vaginal versus abdominal route: smaller absolute difference (0.2-0.4 mm versus 0.8-1.5 mm), greater ratio of differences (85.8-97.8% versus 48.7-72,8%), with p0.05[A1] and similar lower concordance limits (-38 to 3.4 versus -3.6 to 4 mm) for tridimensional ultrasonography and ICC (0.6-0.9 versus 0.7-0.9). from the above, we came to the conclusion that the measurement of the IUS muscle layer, through the vaginal route using tridimensional ultrasonography is more reproducible. Nevertheless, our results do not indicate that this measurement shows any clinical evidence to predict uterine tear, as that was not the aim of this

  20. Impact of Cardiovascular Risk Factors on Carotid Intima-Media Thickness and Degree of Severity: A Cross-Sectional Study.

    Science.gov (United States)

    Ren, Lijie; Cai, Jingjing; Liang, Jie; Li, Weiping; Sun, Zhonghua

    2015-01-01

    Age, hypertension, dyslipidemia and diabetes are common cardiovascular risk factors (CVRFs) that contribute to the development of atherosclerosis in cardiovascular system including carotid artery disease. However, the impact of these risk factors on the increased carotid intima-media thickness (cIMT) and degree of carotid severity remains to be further clarified. This study aims to evaluate the relationship between CVRFs and degree of carotid severity and cIMT in high-risk subjects. Four thousand and three hundred ninety-four subjects with one or more risk factors were retrospectively reviewed in this study. Patients were divided into different groups based on age, the type and quantity of CVRFs. cIMT and degree of carotid artery stenosis were measured and analyzed based on carotid ultrasound imaging with findings compared to the CVRFs to determine the correlation between these variables. Aging was significantly associated with degree of severity (P cardiovascular risk factors, especially with age and hypertension. Carotid atherosclerosis is closely related to the number of cardiovascular risk factors.

  1. Verification of Allowable Stresses In ASME Section III Subsection NH For Grade 91 Steel & Alloy 800H

    Energy Technology Data Exchange (ETDEWEB)

    R. W. Swindeman; M. J. Swindeman; B. W. Roberts; B. E. Thurgood; D. L. Marriott

    2007-11-30

    The database for the creep-rupture of 9Cr-1Mo-V (Grade 91) steel was collected and reviewed to determine if it met the needs for recommending time-dependent strength values, S{sub t}, for coverage in ASME Section III Subsection NH (ASME III-NH) to 650 C (1200 F) and 600,000 hours. The accumulated database included over 300 tests for 1% total strain, nearly 400 tests for tertiary creep, and nearly 1700 tests to rupture. Procedures for analyzing creep and rupture data for ASME III-NH were reviewed and compared to the procedures used to develop the current allowable stress values for Gr 91 for ASME II-D. The criteria in ASME III-NH for estimating S{sub t} included the average strength for 1% total strain for times to 600,000 hours, 80% of the minimum strength for tertiary creep for times to 600,000 hours, and 67% of the minimum rupture strength values for times to 600,000 hours. Time-temperature-stress parametric formulations were selected to correlate the data and make predictions of the long-time strength. It was found that the stress corresponding to 1% total strain and the initiation of tertiary creep were not the controlling criteria over the temperature-time range of concern. It was found that small adjustments to the current values in III-NH could be introduced but that the existing values were conservative and could be retained. The existing database was found to be adequate to extend the coverage to 600,000 hours for temperatures below 650 C (1200 F).

  2. Impact of Cardiovascular Risk Factors on Carotid Intima-Media Thickness and Degree of Severity: A Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Lijie Ren

    Full Text Available Age, hypertension, dyslipidemia and diabetes are common cardiovascular risk factors (CVRFs that contribute to the development of atherosclerosis in cardiovascular system including carotid artery disease. However, the impact of these risk factors on the increased carotid intima-media thickness (cIMT and degree of carotid severity remains to be further clarified. This study aims to evaluate the relationship between CVRFs and degree of carotid severity and cIMT in high-risk subjects.Four thousand and three hundred ninety-four subjects with one or more risk factors were retrospectively reviewed in this study. Patients were divided into different groups based on age, the type and quantity of CVRFs. cIMT and degree of carotid artery stenosis were measured and analyzed based on carotid ultrasound imaging with findings compared to the CVRFs to determine the correlation between these variables.Aging was significantly associated with degree of severity (P < 0.05 and cIMT was significantly increased with age (P < 0.05. Individual CVRF analysis shows that hypertension was more related to the degree of severity than dyslipidemia and diabetes with corresponding abnormal cIMT rates being 79.39%, 72.98% and 32.37%, respectively. The prevalence of carotid atherosclerosis were 20.06%, 22.88% and 28.63%, respectively corresponding to patients with zero, one and more than one chronic diseases. The percentage of abnormal cIMT in hypertensive patient group with dyslipidemia is significantly higher than the other groups (P< 0.05.This study shows a direct correlation between the degree of carotid severity and cIMT and cardiovascular risk factors, especially with age and hypertension. Carotid atherosclerosis is closely related to the number of cardiovascular risk factors.

  3. Development of Environment and Irradiation Effects of High Temperature Materials

    International Nuclear Information System (INIS)

    Ryu, Woo Seog; Kim, D. W.; Kim, S. H.

    2009-11-01

    Proposed materials, Mod.9Cr-1Mo steel (32 mm thickness) and 9Cr-1Mo-1W (100 mm thickness), for the reactor vessel were procured, and welded by the qualified welding technologies. Welding soundness was conformed by NDT, and mechanical testings were done along to weld depth. Two new irradiation capsules for use in the OR test hole of HANARO were designed and fabricated. specimens was irradiated in the OR5 test hole of HANARO with a 30MW thermal power at 390±10 .deg. C up to a fast neutron fluence of 4.4x10 19 (n/cm 2 ) (E>1.0 MeV). The dpa was evaluated to be 0.034∼0.07. Base metals and weldments of both Mod.9Cr-1Mo and 9Cr-1Mo-1W steels were tested tensile and impact properties in order to evaluate the irradiation hardening effects due to neutron irradiation. DBTT of base metal and weldment of Mod.9Cr-1Mo steel were -16 .deg. C and 1 .deg. C, respectively. After neutron irradiation, DBTT of weldment of Mod.9Cr-1Mo steel increased to 25 . deg. C. Alloy 617 and several nickel-base superalloys were studied to evaluate high temperature degradation mechanisms. Helium loop was developed to evaluate the oxidation behaviors of materials in the VHTR environments. In addition, creep behaviors in air and He environments were compared, and oxidation layers formed outer surfaces were measured as a function of applied stress and these results were investigated to the creep life

  4. Measurement of cross sections for alpha-induced reactions on 197Auand thick-target yields for the (alpha,gamma) process on 64Zn and63Cu

    Energy Technology Data Exchange (ETDEWEB)

    Basunia, M.S.; Shugart, H.A.; Smith, A.R.; Norman, E.B.

    2006-08-07

    We have measured the cross sections for the197Au(alpha,gamma)201Tl and 197Au(alpha,2n)199Tl reactions in the 17.9-to 23.9-MeV energy range, and 197Au(alpha,n)200Tl reaction in the 13.4-to 23.9-MeV energy range using an activation technique. Thick-targetyields for the 64Zn(alpha,gamma)68Ge (7- to 14-MeV) and63Cu(alpha,gamma)67Ga (7-MeV) reactions were measured. For allmeasurements, natural elements were bombarded with He+ beams from the88-inch Cyclotron at the Lawrence Berkeley National Laboratory (LBNL).Irradiated samples were counted using a gamma-spectrometry system at LBNLs Low Background Facility. Measured 197Au(alpha,gamma)201Tlcross-sections were compared with the NON-SMOKER theoretical values. Thethick-target yields for the 64Zn(alpha,gamma)68Ge and63Cu(alpha,gamma)67Ga reactions are also compared with the theoreticalyield, calculated numerically using the energy dependent NON-SMOKER crosssection data. In both cases, measured values are found to follow a trendof overlapping the predicted value near the alpha nucleus barrier heightand fall below with a slowly widening difference between them in the subbarrier energy points.

  5. Correction of Thick Foil Errors in Prompt Neutron (CALIFORNIUM-252 Nu), Fission Cross Section (sigma(f)) and Other Ionization Chamber Fission Data Standards.

    Science.gov (United States)

    Cohensedgh, Farhad

    This research resolves two problems that have long been of important concern in experimental fission physics: (1) determination of pulse height distribution response of ionization chambers in fission fragment detection measurements, and (2) correction of "thick-foil effect" systematic errors in standard values of the fundamental parameters of fission physics--the average number of prompt neutrons per fission (=nu), absolute fission activity and true fission rate of samples (TFR), and isotopic fission cross sections (sigma _{f}). Results are obtained by a comprehensive digital simulation of the electrostatics and pulse height distribution response of the parallel-plate, ungridded, electron-pulse ionization fission chamber together with prompt neutron -fragment multiplicity and angular distribution correlations, neutron-fragment coincidence detection and related variations in the 4pi^here around the chamber for a wide range of the relevant factors--foil thickness, alpha particle interference bias level, fission detector configuration characteristics, fissile isotopes (^{252}Cf, ^{235}U, etc.) and other experimental parameters. Isotope-specific double-energy (E_1,E_2) natural variations in fragment spectrum, in fragment-specific range-energy (dE/dx) relations and in prompt neutron-fragment multiplicity (nu) and nuclear temperature dependent angular distribution correlations are simulated in detail. Detailed results are obtained for double-energy, fragment-specific count loss fractions resulting from in -foil fragment absorption and from alpha -interference discrimination as well as for chamber detection efficiency, fragment spectrum distortion and prompt neutron -fragment coincidence detection distribution variations. Decay alpha pulse pileup statistics are discussed, and the behavior of and factors affecting the fragment pulse height distribution tail are analyzed in detail. Fragment pairs and prompt neutrons issued from them are tracked in the 4pi^ace around the

  6. Evaluation of computational models and cross sections used by MCNP6 for simulation of characteristic X-ray emission from thick targets bombarded by kiloelectronvolt electrons

    Science.gov (United States)

    Poškus, A.

    2016-09-01

    This paper evaluates the accuracy of the single-event (SE) and condensed-history (CH) models of electron transport in MCNP6.1 when simulating characteristic Kα, total K (=Kα + Kβ) and Lα X-ray emission from thick targets bombarded by electrons with energies from 5 keV to 30 keV. It is shown that the MCNP6.1 implementation of the CH model for the K-shell impact ionization leads to underestimation of the K yield by 40% or more for the elements with atomic numbers Z 25. The Lα yields are underestimated by more than an order of magnitude in CH mode, because MCNP6.1 neglects X-ray emission caused by electron-impact ionization of L, M and higher shells in CH mode (the Lα yields calculated in CH mode reflect only X-ray fluorescence, which is mainly caused by photoelectric absorption of bremsstrahlung photons). The X-ray yields calculated by MCNP6.1 in SE mode (using ENDF/B-VII.1 library data) are more accurate: the differences of the calculated and experimental K yields are within the experimental uncertainties for the elements C, Al and Si, and the calculated Kα yields are typically underestimated by (20-30)% for the elements with Z > 25, whereas the Lα yields are underestimated by (60-70)% for the elements with Z > 49. It is also shown that agreement of the experimental X-ray yields with those calculated in SE mode is additionally improved by replacing the ENDF/B inner-shell electron-impact ionization cross sections with the set of cross sections obtained from the distorted-wave Born approximation (DWBA), which are also used in the PENELOPE code system. The latter replacement causes a decrease of the average relative difference of the experimental X-ray yields and the simulation results obtained in SE mode to approximately 10%, which is similar to accuracy achieved with PENELOPE. This confirms that the DWBA inner-shell impact ionization cross sections are significantly more accurate than the corresponding ENDF/B cross sections when energy of incident electrons

  7. Creep behavior and evolution of microstructure of modified Grade 91 welded joint after short term exposure at 500 deg C; Fluage a 500 deg C d'un joint soude d'un acier 9Cr-1Mo modifie. Evolution de la microstructure et comportement mecanique

    Energy Technology Data Exchange (ETDEWEB)

    Vivier, F.

    2009-03-15

    With the increase in worldwide energy demand, the nuclear industry is a way of producing electricity on a large scale and to answer to this need. For the design of a new generation of fission nuclear reactors and among six chosen fission reactor systems, France develops in particularly the Very High Temperature Reactor (VHTR) concept. This implies the use of materials that are more and more resistant to high temperature for long-term exposure. AREVA focuses on materials already used in fossil-fuel power plant, so that the mechanical behaviour of Grade 91 (Fe{sub 9}Cr{sub 1}MoNbV) has to be investigated. This ferritic-martensitic steel is considered to be a potential candidate for welded components. Such structures are combined with welded joints, which have to be studied. Three industrial partners (AREVA, CEA, EDF) have launched a study with the Centre des Materiaux in order to investigate the creep of welded joint of Grade 91. The aim of this work is to complete the available database about the mechanical behaviour of Grade 91, base metal and welded joint, during creep tests performed at 500 C up to 4500 h exposure. Thermal aging tests, tensile tests, and creep tests were performed at 450 C and 500 C using both base metal and cross-weld samples. Several geometries of cross-weld creep specimens were tested. The microstructure has not remarkably changed after tests concerning both nature and size of precipitates, and the characteristic size of the matrix sub-structure. The creep damage is not developed in the ruptured specimens after creep tests. Only little damage by cavity nucleation and growth was found in the creep specimens. Creep fracture at 500 C takes places by viscoplastic flow, contrary to tests performed at 625 C where the creep-induced damage governs the creep rupture at least for long-term lifetime. From creep curves of base metal and cross-weld specimens, a phenomenological model is proposed. The flow rule is a Norton power law with a stress exponent of 19 in the case of base metal and 18 in the case of welded joint. These high values of Norton exponent indicate the existence of internal stress and suggest that the mechanism which governs the creep deformation might be dislocation glide. The rupture of cross-weld creep specimens takes place in the weld metal, whereas it takes place in the base metal after tensile tests. The heat-affected zone has no obvious role in the mechanical strength of cross-weld specimens at 500 C. In this case, the creep behaviour of the weld metal can be deduced from a combination of the welded joint behaviour and the base metal behaviour. These were identified from experimental creep curves. Another method to determine the weld metal behaviour is to fit the model parameters on creep curves obtained from modified specimens used to test only the weld metal. These results are consistent with open literature data. The proposed model allows determination of a rupture time for longer-term exposure with simple equations and with a good agreement with recent results from CEA. (author)

  8. Influencia de la temperatura de austenización y tiempo de permanencia sobre el tamaño de grano en aceros ferrítico-martensíticos del tipo 9Cr1MoVNb utilizados en calderas supercríticas

    Directory of Open Access Journals (Sweden)

    Gutiérrez-Urrutia, L.

    2001-04-01

    Full Text Available The aim of the present work is to determine the influence of austenitizing temperature holding time and heating velocity on grain size of ferritic-martensitic type 9CrlMoVNb steels developed for Oak Ridge National Laboratories & Combustion Engineering, T91/P91[1] Steels (USA and X10CrMoVNb 9.1 (Europe. The potential benefits of this material, in term of high resistance, good ductily and oxidation resistance, weldability and in particular good high temperature creep strength, are now widely acknowledged, particulary by supercritical boilers (P = 300 bar, T = 550±50 °C. The studied steels have been produced in, high frecuency induction vacum furnaces and hot-rolled.

    Se estudia la influencia de la temperatura de austenización, tiempo de permanencia a esta temperatura y velocidad de calentamiento sobre el tamaño de grano de varios aceros ferrítico-martensíticos de última generación del tipo 9CrlMoVNb, desarrollados por Oak Ridge National Laboratories (ORNL conjuntamente con Combustion Enginering en USA, conocidos por ASME/ASTM por las designaciones T91/P91[1] y en Europa como X10CrMoVNb9.1. Son aceros ductiles y tenaces que presentan muy buenas propiedades de resistencia a fluencia, soldabilidad y conductividad térmica. Son cada vez más utilizados como tubos de alta temperatura (550±50 °C y presión (300 bar en calderas supercríticas para centrales térmicas avanzadas. Los aceros estudiados se han fabricado en hornos de inducción de alta frecuencia al vacío y laminados en caliente.

  9. Test-Retest Reliability of Muscle Thickness, Echo-Intensity and Cross Sectional Area of Quadriceps and Hamstrings Muscle Groups Using B-mode Ultrasound

    Directory of Open Access Journals (Sweden)

    Cassio V. Ruas

    2017-01-01

    Full Text Available Ultrasound muscle images have been extensively used as tools for investigating, diagnosing and monitoring thigh muscles. However, there is a lack of information examining ultrasound reliability of quadriceps and hamstrings images for research and clinical use. Objectives: To determine the reliability of muscle thickness (MT, echo intensity (EI and cross sectional area (CSA of quadriceps and hamstrings muscle groups. Methods: Single transverse images of the rectus femoris (RF, vastus intermedius (VI, vastus medialis (VM, vastus lateralis (VL, biceps femoris long head (BFlh, semitendinosus (ST, and semimembranosus (SM muscles were scanned in the right and left legs of ten healthy collegiate men (age 23.4 ± 2.2 yrs, mass 71.7 ± 11.7 kg, height 1.73 ± 0.06 m between two sessions with one day interval. Intraclass correlation coefficients (ICCs, standard error of measurement (SEM, and minimum difference to be considered “real” (MD were measured for MT, EI, and CSA. Results: A range of 0.97-0.99, 0.83-0.88, and 0.86-0.97 (ICC; 0.72-1.38, 2.73-3.41, and 0.36-1.04 (SEM; and 2.01-3.82, 7.56-9.46, and 0.99-2.89 (MD were found for quadriceps muscles, and 0.93-0.99, 0.74-0.90, and 0.89-0.96 (ICC; 0.73-1.94, 3.29-4.98, and 0.69-1.08 (SEM; and 2.03-5.38, 9.13-13.81, and 1.91-2.98 (MD were found for hamstrings muscles. Conclusions: These results suggest that ultrasound imaging of both quadriceps and hamstrings muscle architecture is a reliable technique for assessing thigh musculoskeletal tissue. The anatomical sites, as well as ultrasound adjustments, images, and results utilized here may assist future researchers and clinicians as reference tools when measuring quadriceps and hamstrings musculature.

  10. Subclinical hypothyroidism is associated with higher carotid intima-media thickness in cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

    Science.gov (United States)

    Peixoto de Miranda, É J F; Bittencourt, M S; Pereira, A C; Goulart, A C; Santos, I S; Lotufo, P A; Bensenor, I M

    2016-10-01

    Although subclinical hypothyroidism (SCH) is associated with cardiovascular risk, there is scarce data about subclinical atherosclerosis in subjects with SCH. We aimed to analyze the association between SCH and carotid intima-media thickness (IMT) using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). We included subjects with normal thyroid function (TSH: 0.4-4.0 mIU/l, and normal free thyroxine (FT4): 0.8-1.9 ng/dl) and SCH (TSH ≥ 4.0 mIU/l and normal FT4) evaluated for IMT in a cross-sectional analysis. We excluded individuals using medications that affect thyroid function and those with a history of cardiovascular disease. We performed logistic and linear regression models to evaluate the association with IMT (mean values and categorized at the 75th percentile) as a dependent variable and SCH as an independent variable, adjusted for other cardiovascular risk factors. From 8623 subjects (median age of 50 years; interquartile range: 44-57), 4624 (53.6%) were women, 8095 (93.9%) were euthyroid, and 528 (6.1%) had SCH. Groups varied in age, body mass index, Framingham risk score, Homeostasis Model Assessment for Insulin Resistance (HOMA-IR), C-reactive protein, as well as, IMT, that were all higher in SCH compared to euthyroid participants. SCH is associated with IMT as a continuous variable (β = 0.010, P = 0.036) and IMT >75th percentile: OR = 1.30 (95% CI = 1.06-1.59) in logistic models. Individuals with SCH presented higher IMT compared with euthyroid subjects, even after adjustment for potential confounders. IMT was independently associated with SCH in the baseline of the ELSA-Brasil study. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  11. HIV Infection Is Not Associated with Carotid Intima-Media Thickness in Brazil: A Cross-Sectional Analysis from the INI/ELSA-Brasil Study.

    Science.gov (United States)

    Pacheco, Antonio G; Grinsztejn, Beatriz; Fonseca, Maria de Jesus M da; Griep, Rosane Härter; Lotufo, Paulo; Bensenor, Isabela; Mill, José G; Moreira, Rodrigo de C; Moreira, Ronaldo I; Friedman, Ruth K; Santini-Oliveira, Marilia; Cardoso, Sandra W; Veloso, Valdiléa G; Chor, Dóra

    2016-01-01

    Carotid intima-media thickness (cIMT) has been used as an early marker of atherosclerotic disease in the general population. Recently its role among HIV-infected patients has been questioned. To date, no Brazilian study has compared cIMT in respect to HIV status. We compared data from 535 patients actively followed in a prospective cohort in Rio de Janeiro (HIV group); 88 HIV-negative individuals who were nominated by patients (friend controls-FCs); and 10,943 participants of the ELSA-Brasil study. Linear regression models were used to study associations of the 3 groups and several covariables with cIMT. Propensity scores weighting (PSW) were also employed to balance data. Median thickness in mm (IQR) were 0.54 (0.49,0.62); 0.58 (0.52,0.68); and 0.57 (0.49,0.70), HIV, FCs and ELSA-Brasil groups, respectively (p-value<0.001). The best linear model chosen did not include the group variables, after adjusting for all the variables chosen, showing no difference of cIMT across groups. Similar results were obtained with PSW. Several traditional CVD risk factors were also significantly associated with cIMT: female gender, higher education and higher HDL were negatively associated while risk factors were older age, current/former smoker, AMI/stroke family history, CVD history, hypertension, DM, higher BMI and total cholesterol. We show for the first time in a middle-income setting that cIMT, is not different in HIV-infected patients in Rio de Janeiro compared with 2 different groups of non-HIV-infected individuals. Traditional CVD risk factors are associated with this outcome. Our results point out that high standards of care and prevention for CVD risk factors should always be sought both in the HIV-infected and non-infected populations to prevent CVD-related events.

  12. Sonographic Measurement of Lower Uterine Segment Thickness to Predict Uterine Rupture During a Trial of Labor in Women With Previous Cesarean Section: A Meta-analysis

    NARCIS (Netherlands)

    Kok, N.; Wiersma, I. C.; Opmeer, B. C.; de Graaf, I. M.; Mol, B. W.; Pajkrt, E.

    2014-01-01

    Along with the increasing rate of cesarean section (CS) births has been a concomitant decrease in the rate of vaginal birth after cesarean (VBAC), mostly due to concerns about uterine rupture during a trial of labor (TOL). The risk of uterine rupture in laboring women with a previous CS must be

  13. Obtention of differential sections in nuclear reactions using a thick target; Obtencion de secciones diferenciales en reacciones nucleares usando un blanco grueso

    Energy Technology Data Exchange (ETDEWEB)

    Chavez R, R

    2000-07-01

    The nuclear reaction analysis (NRA) technique is used mainly for detecting the presence and concentration of light elements of great importance such as: carbon, nitrogen and oxygen. This work has the objective to obtain the differential sections of {sup 16} O and {sup 14} N starting from the irradiation with deuterons of TiSrO{sub 3} samples, of AIN and AIN{sub 2} at energies of 2000 KeV and 1800 KeV respectively. The present work have four chapters; chapter 1 is focused to the physical aspects which takes part in the NRA technique. The technical requirements as well as the necessary equipment for developing the techniques are described in the chapter 2. In chapter 3 it is described the algorithm developed for to obtain the differential sections starting from experimental data, and finally, in chapter 4 are given the results and conclusions. (Author)

  14. Association of Cardiovascular Risk Factors with Carotid Intima Media Thickness in Patients with Rheumatoid Arthritis with Low Disease Activity Compared to Controls: A Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Deborah F van Breukelen-van der Stoep

    Full Text Available Rheumatoid arthritis (RA has been identified as an independent cardiovascular risk factor. The importance of risk factors such as hypertension and hyperlipidemia in the generation of atherosclerosis in RA patients is unclear. This study analyzed clinical parameters associated with carotid intima media thickness (cIMT in patients with RA.Subjects with RA and healthy controls without RA, both without known cardiovascular disease, were included. Participants underwent a standard physical examination and laboratory measurements including a lipid profile. cIMT was measured semi-automatically by ultrasound.In total 243 RA patients and 117 controls were included. The median RA disease duration was 7 years (IQR 2-14 years. The median DAS28 was 2.4 (IQR 1.6-3.2 and 114 (50.4% of the RA patients were in remission. The presence of RA and cIMT were not associated (univariate analysis. Multivariable regression analysis showed that cIMT in RA patients was associated with age (B = 0.006, P<0.001 and systolic blood pressure (B = 0.003, P = 0.003. In controls, cIMT was associated with age (B = 0.006, P<0.001 and smoking (B = 0.097, P = 0.001.cIMT values were similar between RA patients and controls. Hypertension was strongly associated with cIMT in RA patients. After adjustment, no association between cIMT and specific RA disease characteristics was found in this well treated RA cohort.

  15. Association between carotid intima-media thickness and fasting blood glucose level: A population-based cross-sectional study among low-income adults in rural China.

    Science.gov (United States)

    Gao, Liu; Bai, Lingling; Shi, Min; Ni, Jingxian; Lu, Hongyan; Wu, Yanan; Tu, Jun; Ning, Xianjia; Wang, Jinghua; Li, Yukun

    2017-11-01

    Carotid intima-media thickness (CIMT) is an established predictor of cardiovascular disease and stroke. We aimed to identify the association between CIMT and blood glucose, as well as the risk factors associated with increased CIMT in a low-income Chinese population. Stroke-free and cardiovascular disease-free residents aged ≥45 years were recruited. B-mode ultrasonography was carried out to measure CIMT. There were 2,643 participants (71.0%) in the normal group, 549 (14.7%) in the impaired fasting glucose group and 533 (14.3%) in the diabetes mellitus group. The determinants of increased CIMT were older age; male sex; low education; hypertension; smoking; high levels of systolic blood pressure, fasting blood glucose and low-density lipoprotein cholesterol; and low levels of diastolic blood pressure, triglycerides and high-density lipoprotein cholesterol, after adjusting for covariates. Age and hypertension were the common risk factors for increased CIMT in all three groups. Furthermore, male sex, smoking and high low-density lipoprotein cholesterol level were positively associated with the mean CIMT in the normal group; high triglycerides levels were negatively associated with the mean CIMT in the impaired fasting glucose group; and alcohol consumption was an independent risk factor for mean CIMT in the diabetes mellitus group. Hypertension was the greatest risk factor for increased CIMT. These findings suggest that it is crucial to manage and control traditional risk factors in low-income populations in China in order to decelerate the recent dramatic increase in stroke incidence, and to reduce the burden of stroke. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

  16. [Distribution of carotid intima media thickness in men and women with and without coronary heart disease. Cross-sectional data of the Heinz Nixdorf Recall Study].

    Science.gov (United States)

    Bauer, M; Hoffmann, B; Möhlenkamp, S; Lehmann, N; Moebus, S; Roggenbuck, U; Berg, C; Kälsch, H; Mahabadi, A A; Kara, K; Jöckel, K-H; Erbel, R

    2013-08-01

    The aim of this study was to introduce population-based sex and age-stratified distributions of carotid intima media thickness (CIMT), to compare fixed cut-off and percentile values for subjects with and without known coronary heart disease (CHD) and to describe CIMT percentiles. Between 2000 and 2003, a total of 4,814 subjects aged 45-75 years were recruited into the Heinz Nixdorf recall study (HNR). Ultrasound examination of extracranial arteries was performed and the CIMT was measured manually over a distance of 1 cm proximal to the bulb in the common carotid artery (CCA). Both sides were measured and the average of the right and left artery were calculated (mean CIMT). The CIMT was measured for 1,749 men and 1,802 women without prevalent CHD and 177 men and 50 women with prevalent CHD. Mean CIMT values were higher in men compared to women (men 0.71 ± 0.14 mm vs. women 0.65 ± 0.11 mm, p ≤ 0.0001) and in subjects with CHD compared to those without (men with and without CHD: 0.76 ± 0.14 mm and 0.70 ± 0.14 mm, p ≤ 0.0001, respectively; women with and without CHD: 0.73 ± 0.15 mm and 0.64 ± 0.11 mm, p ≤ 0.0001, respectively). In men the mean CIMT increased from 0.62 ± 0.10 mm in the youngest (45-49 years old) up to 0.79 ± 0.13 mm in the highest age group (≥ 70 years) (0.57 ± 0.08 mm up to 0.71 ± 0.12 mm in women, p ≤ 0.0001 for both). Compared to international studies similar CIMT distributions were found in this study using both continuous and percentile distributions. However, lower CIMT values were observed in older participants, which can be explained by exclusion of carotid plaque formation in CIMT measurements.

  17. Correlation of biomarkers thiobarbituric acid reactive substance, nitric oxide and central subfield and cube average thickness in diabetic retinopathy: a cross-sectional study.

    Science.gov (United States)

    Ruia, Surabhi; Saxena, Sandeep; Prasad, S; Sharma, Shashi R; Akduman, Levent; Khanna, Vinay K

    2016-01-01

    To evaluate the role of thiobarbituric acid reactive substance (TBARS) and nitric oxide (NO) as biochemical biomarkers and central subfield (CST) and cube average thickness (CAT) as biomarkers for medical imaging in diabetic retinopathy. Forty consecutive cases of diabetic retinopathy and 20 healthy controls were included. Cases were divided into two groups: non proliferative diabetic retinopathy (n = 20) and proliferative diabetic retinopathy (n = 20) according to ETDRS classification. LogMAR visual acuity was documented. Plasma levels of TBARS, NO and glycated hemoglobin (HbA1c) were measured using standard protocol. CST and CAT were analyzed on spectral domain optical coherence tomography. Data was analyzed statistically. Increased severity of diabetic retinopathy was associated with an increase in plasma levels of TBARS (F = 10.92; p diabetic retinopathy. Pearson's correlation analysis revealed a positive correlation of TBARS with CST (r = 0.29; p = 0.038) and CAT (r = 0.31; p = 0.04). A positive correlation of NO with CST (r = 0.27; p = 0.03) and CAT (r = 0.7; p = 0.001) was also observed. On univariate analysis with logMAR visual acuity as dependent variable, a significant increase in visual acuity was observed with increase in independent variables TBARS (B = 0.22; p = 0.004), NO (B = 0.006; p diabetes and HbA1c, it was observed that increase in independent variables TBARS (B = 0.07), NO (B = 0.001) and CST (B = 0.004) independently predict increase in logMAR visual acuity (p diabetic retinopathy. In a clinical retinal setting, CAT and CST will help in early recognition of increase in severity of diabetic retinopathy.

  18. Groping for Quantitative Digital 3-D Image Analysis: An Approach to Quantitative Fluorescence In Situ Hybridization in Thick Tissue Sections of Prostate Carcinoma

    Directory of Open Access Journals (Sweden)

    Karsten Rodenacker

    1997-01-01

    Full Text Available In molecular pathology numerical chromosome aberrations have been found to be decisive for the prognosis of malignancy in tumours. The existence of such aberrations can be detected by interphase fluorescence in situ hybridization (FISH. The gain or loss of certain base sequences in the desoxyribonucleic acid (DNA can be estimated by counting the number of FISH signals per cell nucleus. The quantitative evaluation of such events is a necessary condition for a prospective use in diagnostic pathology. To avoid occlusions of signals, the cell nucleus has to be analyzed in three dimensions. Confocal laser scanning microscopy is the means to obtain series of optical thin sections from fluorescence stained or marked material to fulfill the conditions mentioned above. A graphical user interface (GUI to a software package for display, inspection, count and (semi‐automatic analysis of 3‐D images for pathologists is outlined including the underlying methods of 3‐D image interaction and segmentation developed. The preparative methods are briefly described. Main emphasis is given to the methodical questions of computer‐aided analysis of large 3‐D image data sets for pathologists. Several automated analysis steps can be performed for segmentation and succeeding quantification. However tumour material is in contrast to isolated or cultured cells even for visual inspection, a difficult material. For the present a fully automated digital image analysis of 3‐D data is not in sight. A semi‐automatic segmentation method is thus presented here.

  19. Radioactive thickness gauge (1962)

    International Nuclear Information System (INIS)

    Guizerix, J.

    1962-01-01

    The author describes a thickness gauge in which the scintillating crystal detector alternately 'sees' a radioactive source through the material which is to be measured and then a control source of the same material; the radiations are separated in time by an absorbing valve whose sections are alternately full and hollow. The currents corresponding to the two sources are separated beyond the photomultiplier tube by a detector synchronized with the rotation of the valve. The quotient of these two currents is then obtained with a standard recording potentiometer. It is found that the average value of the response which is in the form G = f(I 1 /I 2 ) is not affected by decay of the radioactive sources, and that it is little influenced by variations of high tension, temperature, or properties of the air in the source detector interval. The performance of the gauge is given. (author) [fr

  20. Association of magnesium in serum and urine with carotid intima-media thickness and serum lipids in middle-aged and elderly Chinese: a community-based cross-sectional study.

    Science.gov (United States)

    Cao, Yi; Wang, Cheng; Guan, Ke; Xu, Ying; Su, Yi-xiang; Chen, Yu-ming

    2016-02-01

    Previous studies suggested that magnesium (Mg) might protect against atherosclerosis, but data were scarce in an Asian population. We examined the association of Mg levels in serum and urine with carotid intima-media thickness (cIMT) and serum lipids in Chinese adults. This community-based cross-sectional study recruited 2,837 participants aged 40-75 years in Guangzhou, China. General information, lifestyle factors, serum and urinary concentrations of Mg and cardiometabolic factors were determined. The cIMTs of the common carotid artery (CCA) and the carotid bifurcation (BIF) were measured ultrasonographically. The mean (SD) concentration of serum Mg was 0.85 (0.07) mmol/L and median (IQR) for urinary Mg excretion was 2.29 (1.56-3.51) mmol/L. After adjustment for potential covariates, both serum and the urinary concentrations of Mg were inversely associated with CCA-IMT, but not with BIF-IMT. The regression coefficients (standard errors) were -100 (29) µm (total), -86 (34) µm (women) and -117 (52) µm (men) CCA-IMT per 1 mmol/L of serum Mg, and -41 (8) µm (total), -41 (10) µm (women) and -44 (15) µm (men) CCA-IMT per 1 unit of urinary Mg/creatinine (log mmol/mmol) (all p < 0.05), respectively. Higher serum Mg levels were associated with higher total cholesterol, HDLc, LDLc and triglyceride, but lower non-HDLc/HDLc in total population (all p < 0.05). Similar relationships of urinary Mg with lipoproteins were also found in total population (all p < 0.05). Higher levels of serum and urinary Mg are associated with lower CCA-IMTs, and the role of Mg in lipid metabolism needs further investigation.

  1. The thickness of glaciers

    International Nuclear Information System (INIS)

    Faraoni, Valerio; Vokey, Marshall W

    2015-01-01

    Basic formulae and results of glacier physics appearing in glaciology textbooks can be derived from first principles introduced in algebra-based first year physics courses. We discuss the maximum thickness of alpine glaciers and ice sheets and the relation between maximum thickness and length of an ice sheet. Knowledge of ordinary differential equations allows one to derive also the local ice thickness. (paper)

  2. The thickness of glaciers

    Science.gov (United States)

    Faraoni, Valerio; Vokey, Marshall W.

    2015-09-01

    Basic formulae and results of glacier physics appearing in glaciology textbooks can be derived from first principles introduced in algebra-based first year physics courses. We discuss the maximum thickness of alpine glaciers and ice sheets and the relation between maximum thickness and length of an ice sheet. Knowledge of ordinary differential equations allows one to derive also the local ice thickness.

  3. Three-dimensional primate molar enamel thickness.

    Science.gov (United States)

    Olejniczak, Anthony J; Tafforeau, Paul; Feeney, Robin N M; Martin, Lawrence B

    2008-02-01

    Molar enamel thickness has played an important role in the taxonomic, phylogenetic, and dietary assessments of fossil primate teeth for nearly 90 years. Despite the frequency with which enamel thickness is discussed in paleoanthropological discourse, methods used to attain information about enamel thickness are destructive and record information from only a single plane of section. Such semidestructive planar methods limit sample sizes and ignore dimensional data that may be culled from the entire length of a tooth. In light of recently developed techniques to investigate enamel thickness in 3D and the frequent use of enamel thickness in dietary and phylogenetic interpretations of living and fossil primates, the study presented here aims to produce and make available to other researchers a database of 3D enamel thickness measurements of primate molars (n=182 molars). The 3D enamel thickness measurements reported here generally agree with 2D studies. Hominoids show a broad range of relative enamel thicknesses, and cercopithecoids have relatively thicker enamel than ceboids, which in turn have relatively thicker enamel than strepsirrhine primates, on average. Past studies performed using 2D sections appear to have accurately diagnosed the 3D relative enamel thickness condition in great apes and humans: Gorilla has the relatively thinnest enamel, Pan has relatively thinner enamel than Pongo, and Homo has the relatively thickest enamel. Although the data set presented here has some taxonomic gaps, it may serve as a useful reference for researchers investigating enamel thickness in fossil taxa and studies of primate gnathic biology.

  4. The Impact of Material and Design Criteria on the Assessment of Negligible Creep

    International Nuclear Information System (INIS)

    Jetter, Robert I.; Sham, Sam; Swindeman, Robert W.

    2009-01-01

    Two of the proposed High Temperature Gas Reactors (HTGRs) under consideration for a demonstration plant have the design object of avoiding creep effects during normal operation. The goal of negligible creep could have different interpretations depending upon what failure modes are considered and associated criteria for avoiding the effects of creep. This work addresses the criteria for negligible creep in Subsection NH of Section III of the ASME B and PV Code, other international design codes and some currently suggested criteria modifications and their impact on permissible operating temperatures for various reactor pressure vessel materials. There are a number of other considerations for the selection of vessel material besides avoiding creep effects. Of particular interest for this review are (1) the materials allowable stress level and impact on wall thickness (the goal being to minimize required wall thickness) and (2) ASME Code approval (inclusion as a permitted material in the relevant Section and Subsection of interest) to expedite regulatory review and approval. The application of negligible creep criteria to two of the candidate materials, SA533 and Mod 9Cr-1Mo, and to a potential alternate, normalized and tempered 2 Cr-1Mo, are illustrated and the relative advantages and disadvantages are discussed.

  5. In a dynamic lifting task, the relationship between cross-sectional abdominal muscle thickness and the corresponding muscle activity is affected by the combined use of a weightlifting belt and the Valsalva maneuver.

    Science.gov (United States)

    Blanchard, Trevor W; Smith, Camille; Grenier, Sylvain G

    2016-06-01

    It has been shown that under isometric conditions, as the activity of the abdominal muscles increases, the thicknesses of the muscles also increase. The purpose of this experiment was to determine whether change in muscle thickness could be used as a measure of muscle activity during a deadlift as well as determining the effect of a weightlifting belt and/or the Valsalva maneuver on the muscle thicknesses. The Transversus Abdominis (TrA) and Internal Obliques (IO) muscles were analyzed at rest and during a deadlift. Muscle thickness was measured using ultrasound imaging and muscle activity was simultaneously recorded using electromyography. Each subject performed deadlift under normal conditions, while performing the Valsalva maneuver, while wearing a weightlifting belt and while both utilizing the belt and the Valsalva maneuver. There was no relationship between change in muscle thickness and muscle activity for both the TrA and IO (R(2)abdominal muscle thickness whereas the belt limited muscle expansion; each with an increase in activity. These results indicate that ultrasound cannot be used to measure muscle activity for a deadlift and that the belt affects how the IO and TrA function together. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Pavement thickness evaluation using ground penetrating radar

    Science.gov (United States)

    Harris, Dwayne Arthur

    Accurate knowledge of pavement thickness is important information to have both at a network and project level. This information aids in pavement management and design. Much of the time this information is missing, out of date, or unknown for highway sections. Current technologies for determining pavement thickness are core drilling, falling weight deflectometer (FWD), and ground penetrating radar (GPR). Core drilling provides very accurate pin point pavement thickness information; however, it is also time consuming, labor intensive, intrusive to traffic, destructive, and limited in coverage. FWD provides nondestructive estimates of both a surface thickness and total pavement structure thickness, including pavement, base and sub-base. On the other hand, FWD is intrusive to traffic and affected by the limitations and assumptions the method used to estimate thickness. GPR provides pavement surface course thickness estimates with excellent data coverage at highway speed. Yet, disadvantages include the pavement thickness estimation being affected by the electrical properties of the pavement, limitations of the system utilized, and heavy post processing of the data. Nevertheless, GPR has been successfully utilized by a number of departments of transportation (DOTs) for pavement thickness evaluation. This research presents the GPR thickness evaluation methods, develops GPRPAVZ the software used to implement the methodologies, and addresses the quality of GPR pavement thickness evaluation.

  7. Visualization of atherosclerosis as detected by coronary artery calcium and carotid intima-media thickness reveals significant atherosclerosis in a cross-sectional study of psoriasis patients in a tertiary care center.

    Science.gov (United States)

    Santilli, S; Kast, D R; Grozdev, I; Cao, L; Feig, R L; Golden, J B; Debanne, S M; Gilkeson, R C; Orringer, C E; McCormick, T S; Ward, N L; Cooper, K D; Korman, N J

    2016-07-22

    Psoriasis is a chronic inflammatory disease of the skin and joints that may also have systemic inflammatory effects, including the development of cardiovascular disease (CVD). Multiple epidemiologic studies have demonstrated increased rates of CVD in psoriasis patients, although a causal link has not been established. A growing body of evidence suggests that sub-clinical systemic inflammation may develop in psoriasis patients, even from a young age. We aimed to evaluate the prevalence of atherosclerosis and identify specific clinical risk factors associated with early vascular inflammation. We conducted a cross-sectional study of a tertiary care cohort of psoriasis patients using coronary artery calcium (CAC) score and carotid intima-media thickness (CIMT) to detect atherosclerosis, along with high sensitivity C-reactive protein (hsCRP) to measure inflammation. Psoriasis patients and controls were recruited from our tertiary care dermatology clinic. Presence of atherosclerosis was defined using validated numeric values within CAC and CIMT imaging. Descriptive data comparing groups was analyzed using Welch's t test and Pearson Chi square tests. Logistic regression was used to analyze clinical factors associated with atherosclerosis, and linear regression to evaluate the relationship between psoriasis and hsCRP. 296 patients were enrolled, with 283 (207 psoriatic and 76 controls) having all data for the hsCRP and atherosclerosis analysis. Atherosclerosis was found in 67.6 % of psoriasis subjects versus 52.6 % of controls; Psoriasis patients were found to have a 2.67-fold higher odds of having atherosclerosis compared to controls [95 % CI (1.2, 5.92); p = 0.016], after adjusting for age, gender, race, BMI, smoking, HDL and hsCRP. In addition, a non-significant trend was found between HsCRP and psoriasis severity, as measured by PASI, PGA, or BSA, again after adjusting for confounders. A tertiary care cohort of psoriasis patients have a high prevalence of early

  8. Gas turbine bucket wall thickness control

    Science.gov (United States)

    Stathopoulos, Dimitrios; Xu, Liming; Lewis, Doyle C.

    2002-01-01

    A core for use in casting a turbine bucket including serpentine cooling passages is divided into two pieces including a leading edge core section and a trailing edge core section. Wall thicknesses at the leading edge and the trailing edge of the turbine bucket can be controlled independent of each other by separately positioning the leading edge core section and the trailing edge core section in the casting die. The controlled leading and trailing edge thicknesses can thus be optimized for efficient cooling, resulting in more efficient turbine operation.

  9. Education and "Thick" Epistemology

    Science.gov (United States)

    Kotzee, Ben

    2011-01-01

    In this essay Ben Kotzee addresses the implications of Bernard Williams's distinction between "thick" and "thin" concepts in ethics for epistemology and for education. Kotzee holds that, as in the case of ethics, one may distinguish between "thick" and "thin" concepts of epistemology and, further, that this distinction points to the importance of…

  10. Heavy section steel technology program. Technical report No. 36. The irradiated fracture toughness of ASTM A533, Grade B, Class 1 steel measured with a four inch thick compact tension specimen

    International Nuclear Information System (INIS)

    Williams, J.A.

    1975-01-01

    The fracture toughness of an ASTM A533-B four inch thick compact tension specimen irradiated to approximately 3.8 x 10 19 n/cm 2 (E greater than 1 MeV) at 550 0 F was determined to be 80 ksi √in at a test temperature of 200 0 F. Smaller 0.394 inch thick fracture specimens were tested prior to the large specimen test to aid in establishing the test temperature and to compare the fracture transition of large and small irradiated specimens. The K/sub Ic.394/ toughness transition as measured at 100 ksi √in was observed at a temperature of 210 0 F; plate RW and WR orientations were comparable. Fracture toughness behavior of the small specimens closely predicts the large specimen behavior in the transition region. 23 references. (U.S.)

  11. Thick-Big Descriptions

    DEFF Research Database (Denmark)

    Lai, Signe Sophus

    to a commercial logic (boyd & Crawford 2011) and is as such directed by motives that call for specific types of sellable user data and specific segmentation strategies. In combining big data and ‘thick descriptions’ (Geertz 1973) scholars need to question how ethnographic fieldwork might map the ‘data not seen...

  12. The use of finite element analysis and notch tensile testing to determine the cryogenic fracture toughness of thick section weldment in forged CSUS-JN1 plate with Inconel 625 type filler metals

    International Nuclear Information System (INIS)

    Shindo, Yasuhide; Mano, Yasunori; Horiguchi, Katsumi; Sugo, Tomo

    2000-01-01

    The use of the notch tensile test to estimate the elastic-plastic fracture toughness (J IC ) of structural alloys and weldments for superconducting magnets in fusion energy systems was studied. Notch tensile tests were performed with small round bar specimens containing an electro discharge machined (EDM) notch at liquid helium temperature (4 K) using crosshead rates of 3.3 x 10 -3 and 20 mm/s. Notch tensile test specimens were 5 mm in diameter with a 30-mm reduced section. In the mid section of the specimen a 1 mm deep EDM notch of 0.2 mm width was machined around the girth, thus maintaining a starting diameter of 3 mm. Correlations between notch tensile strength, failure energy absorption, and J IC were assessed. A finite element analysis was also performed to compute directly the J-values. Comparisons of the predicted J IC with results obtained from conventional JIS Z 2284 standard tests were made. (author)

  13. Coating thickness measuring device

    International Nuclear Information System (INIS)

    Joffe, B.B.; Sawyer, B.E.; Spongr, J.J.

    1984-01-01

    A device especially adapted for measuring the thickness of coatings on small, complexly-shaped parts, such as, for example, electronic connectors, electronic contacts, or the like. The device includes a source of beta radiation and a radiation detector whereby backscatter of the radiation from the coated part can be detected and the thickness of the coating ascertained. The radiation source and detector are positioned in overlying relationship to the coated part and a microscope is provided to accurately position the device with respect to the part. Means are provided to control the rate of descent of the radiation source and radiation detector from its suspended position to its operating position and the resulting impact it makes with the coated part to thereby promote uniformity of readings from operator to operator, and also to avoid excessive impact with the part, thereby improving accuracy of measurement and eliminating damage to the parts

  14. Symptoms of pain do not correlate with rotator cuff tear severity: a cross-sectional study of 393 patients with a symptomatic atraumatic full-thickness rotator cuff tear.

    Science.gov (United States)

    Dunn, Warren R; Kuhn, John E; Sanders, Rosemary; An, Qi; Baumgarten, Keith M; Bishop, Julie Y; Brophy, Robert H; Carey, James L; Holloway, G Brian; Jones, Grant L; Ma, C Benjamin; Marx, Robert G; McCarty, Eric C; Poddar, Sourav K; Smith, Matthew V; Spencer, Edwin E; Vidal, Armando F; Wolf, Brian R; Wright, Rick W

    2014-05-21

    For many orthopaedic disorders, symptoms correlate with disease severity. The objective of this study was to determine if pain level is related to the severity of rotator cuff disorders. A cohort of 393 subjects with an atraumatic symptomatic full-thickness rotator-cuff tear treated with physical therapy was studied. Baseline pretreatment data were used to examine the relationship between the severity of rotator cuff disease and pain. Disease severity was determined by evaluating tear size, retraction, superior humeral head migration, and rotator cuff muscle atrophy. Pain was measured on the 10-point visual analog scale (VAS) in the patient-reported American Shoulder and Elbow Surgeons (ASES) score. A linear multiple regression model was constructed with use of the continuous VAS score as the dependent variable and measures of rotator cuff tear severity and other nonanatomic patient factors as the independent variables. Forty-eight percent of the patients were female, and the median age was sixty-one years. The dominant shoulder was involved in 69% of the patients. The duration of symptoms was less than one month for 8% of the patients, one to three months for 22%, four to six months for 20%, seven to twelve months for 15%, and more than a year for 36%. The tear involved only the supraspinatus in 72% of the patients; the supraspinatus and infraspinatus, with or without the teres minor, in 21%; and only the subscapularis in 7%. Humeral head migration was noted in 16%. Tendon retraction was minimal in 48%, midhumeral in 34%, glenohumeral in 13%, and to the glenoid in 5%. The median baseline VAS pain score was 4.4. Multivariable modeling, controlling for other baseline factors, identified increased comorbidities (p = 0.002), lower education level (p = 0.004), and race (p = 0.041) as the only significant factors associated with pain on presentation. No measure of rotator cuff tear severity correlated with pain (p > 0.25). Anatomic features defining the severity of

  15. Common carotid intima media thickness and ankle-brachial pressure index correlate with local but not global atheroma burden: a cross sectional study using whole body magnetic resonance angiography.

    Science.gov (United States)

    Weir-McCall, Jonathan R; Khan, Faisel; Lambert, Matthew A; Adamson, Carly L; Gardner, Michael; Gandy, Stephen J; Ramkumar, Prasad Guntur; Belch, Jill J F; Struthers, Allan D; Rauchhaus, Petra; Morris, Andrew D; Houston, J Graeme

    2014-01-01

    Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA). 50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR). The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0 = normal, 1 = <50%, 2 = 50-70%, 3 = 70-99%, 4 = vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated. The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (β 0.32, p = 0.045), however this was due to its strong correlation with the neck and thoracic segments (β 0.42 p = 0.01) with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (β -0.39, p = 0.012), which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (β 0.13 p = 0.45), while the correlation between ABPI and atheroma burden persisted (β -0.45 p = 0.005). ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral arterial disease. However this is primarily due to

  16. STEM tomography for thick biological specimens

    Energy Technology Data Exchange (ETDEWEB)

    Aoyama, Kazuhiro [FEI Company Japan Ltd., Application Laboratory, NSS-II Building, 2-13-34 Kohnan, Minato-ku, Tokyo 108-0075 (Japan)], E-mail: kazuhiro.aoyama@fei.com; Takagi, Tomoko [FEI Company Japan Ltd., Application Laboratory, NSS-II Building, 2-13-34 Kohnan, Minato-ku, Tokyo 108-0075 (Japan); Laboratory of Electron Microscopy, Japan Women' s University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681 (Japan); Hirase, Ai; Miyazawa, Atsuo [Bio-multisome Research Team, RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); CREST, JST (Japan)

    2008-12-15

    Scanning transmission electron microscopy (STEM) tomography was applied to biological specimens such as yeast cells, HEK293 cells and primary culture neurons. These cells, which were embedded in a resin, were cut into 1-{mu}m-thick sections. STEM tomography offers several important advantages including: (1) it is effective even for thick specimens, (2) 'dynamic focusing', (3) ease of using an annular dark field (ADF) mode and (4) linear contrasts. It has become evident that STEM tomography offers significant advantages for the observation of thick specimens. By employing STEM tomography, even a 1-{mu}m-thick specimen (which is difficult to observe by conventional transmission electron microscopy (TEM)) was successfully analyzed in three dimensions. The specimen was tilted up to 73 deg. during data acquisition. At a large tilt angle, the specimen thicknesses increase dramatically. In order to observe such thick specimens, we introduced a special small condenser aperture that reduces the collection angle of the STEM probe. The specimen damage caused by the convergent electron beam was expected to be the most serious problem; however, the damage in STEM was actually smaller than that in TEM. In this study, the irradiation damage caused by TEM- and STEM-tomography in biological specimens was quantitatively compared.

  17. Nearshore sediment thickness, Fire Island, New York

    Science.gov (United States)

    Locker, Stanley D.; Miselis, Jennifer L.; Buster, Noreen A.; Hapke, Cheryl J.; Wadman, Heidi M.; McNinch, Jesse E.; Forde, Arnell S.; Stalk, Chelsea A.

    2017-04-03

    Investigations of coastal change at Fire Island, New York (N.Y.), sought to characterize sediment budgets and determine geologic framework controls on coastal processes. Nearshore sediment thickness is critical for assessing coastal system sediment availability, but it is largely unquantified due to the difficulty of conducting geological or geophysical surveys across the nearshore. This study used an amphibious vessel to acquire chirp subbottom profiles. These profiles were used to characterize nearshore geology and provide an assessment of nearshore sediment volume. Two resulting sediment-thickness maps are provided: total Holocene sediment thickness and the thickness of the active shoreface. The Holocene sediment section represents deposition above the maximum flooding surface that is related to the most recent marine transgression. The active shoreface section is the uppermost Holocene sediment, which is interpreted to represent the portion of the shoreface thought to contribute to present and future coastal behavior. The sediment distribution patterns correspond to previously defined zones of erosion, accretion, and stability along the island, demonstrating the importance of sediment availability in the coastal response to storms and seasonal variability. The eastern zone has a thin nearshore sediment thickness, except for an ebb-tidal deposit at the wilderness breach caused by Hurricane Sandy. Thicker sediment is found along a central zone that includes shoreface-attached sand ridges, which is consistent with a stable or accretional coastline in this area. The thickest overall Holocene section is found in the western zone of the study, where a thicker lower section of Holocene sediment appears related to the westward migration of Fire Island Inlet over several hundred years.

  18. Choroidal thickness in Malaysian eyes with full-thickness macular holes

    Directory of Open Access Journals (Sweden)

    Chew Y Tan

    2018-02-01

    Full Text Available AIM: To compare choroidal thickness at the macula in eyes with unilateral idiopathic full-thickness macular holes(FTMHwith that of unaffected fellow eyes, and eyes of normal control patients.METHODS: Cross-sectional study. Thirty patients with unilateral idiopathic FTMH and thirty age, sex, and race-matched controls were recruited. Axial lengths were measured using laser interferometry. Enhanced depth imaging optical coherence tomography images were obtained using Heidelberg spectral-domain optical coherence tomography. Choroidal thickness was measured at the fovea, and at 1 mm and 2 mm nasally, temporally, superiorly and inferiorly from the center of the fovea. Statistical analysis was performed using independent and paired t-tests, chi-square tests, and Pearson correlation tests(PRESULTS: The mean subfoveal choroidal thickness was 201.0±44.0 μm in the FTMH group, 225.3±51.4 μm in the fellow eye group and 262.3±70.3 μm in the control group. The choroid was thinner in FTMH eyes at all locations when compared to control eyes(PPP>0.05. Choroidal thickness was generally highest subfoveally and lowest nasally. Subfoveal choroidal thickness was negatively correlated with age(r=-0.278, P=0.032, and axial length(r=-0.328, P=0.011.CONCLUSION: Choroidal thickness is lower in both eyes of patients with unilateral FTMH compared to healthy control eyes.

  19. Medida da espessura do segmento uterino inferior em gestantes com cesárea prévia: análise da reprodutibilidade intra- e interobservador por ultra-sonografia bi- e tridimensional Lower uterine segment thickness measurement in pregnant women with previous caesarean section: intra- and interobserver reliability analysis using bi- and tridimensional ultrasonography

    Directory of Open Access Journals (Sweden)

    Daniela de Abreu Barra

    2008-03-01

    interferir na conduta do obstetra ou antecipar o parto, foi feito por medidas bidimensionais abdominais da espessura total.PURPOSE: to compare the intra and interobserver reproducibility of the total thickness measurement of the inferior uterine segment (IUS, through the abdominal route, and of the muscle layer measurement, through the vaginal route, using bi and tridimensional ultrasonography. METHODS: the IUS thickness measurement of 30 women, between the 36th and 39th weeks of gestation with previous caesarean section, done by two observers, was studied. Abdominal ultrasonography with the patient in both supine and lithotomy position was performed. In the sagittal section, the IUS was identified and four bidimensional images and two tridimensional blocks of the total thickness were collected through the abdominal route, and the same for the muscle layer, through the vaginal route. Tridimensional acquisitions were manipulated in the multiplanar mode. The time was measured with a chronometer. Reproducibility was evaluated by the computation of the absolute difference between measurements, the ratio of differences smaller than 1 mm, the intraclass coefficient (ICC, and the Bland and Altman's concordance limits. RESULTS: the average bidimensional measurement of IUS thickness was 7.4 mm through the abdominal and 2.7 mm through the vaginal route, and the tridimensional measurement was 6.9 mm through the abdominal and 5.1 mm through the vaginal route. Intra- and interobserver reproducibility of vaginal versus abdominal route: smaller absolute difference (0.2-0.4 mm versus 0.8-1.5 mm, greater ratio of differences (85.8-97.8% versus 48.7-72,8%, with p0.05[A1] and similar lower concordance limits (-38 to 3.4 versus -3.6 to 4 mm for tridimensional ultrasonography and ICC (0.6-0.9 versus 0.7-0.9. CONCLUSIONS: from the above, we came to the conclusion that the measurement of the IUS muscle layer, through the vaginal route using tridimensional ultrasonography is more reproducible

  20. Measurement of the bremsstrahlung spectra generated from thick ...

    Indian Academy of Sciences (India)

    with those predicted by Monte-Carlo (MC) calculations using PENELOPE code. A close agreement between the ... cross-sections; Monte-Carlo simulation. PACS Nos 34.80.-i; 78.70.-g; 33.20. ... Quarles [13] proposed a model for calculating the thick target bremsstrahlung cross- sections for incident electrons having ...

  1. Enamel thickness in Asian human canines and premolars

    OpenAIRE

    Feeney, Robin N. M.; Zermeno, John P.; Reid, Donald J.; et al.

    2010-01-01

    Dental enamel thickness continues to feature prominently in anthropological studies of ape and human evolution, as well as studies of preventative oral care and treatment. Traditional studies of enamel thickness require physical sectioning of teeth for linear and scaled measurements. Recent applications of microtomographic imaging allow scientists to employ larger and more diverse samples, including global samples of recent humans as well as fossil hominin teeth. Unfortunately, little is know...

  2. Model-based cartilage thickness measurement in the submillimeter range

    International Nuclear Information System (INIS)

    Streekstra, G. J.; Strackee, S. D.; Maas, M.; Wee, R. ter; Venema, H. W.

    2007-01-01

    Current methods of image-based thickness measurement in thin sheet structures utilize second derivative zero crossings to locate the layer boundaries. It is generally acknowledged that the nonzero width of the point spread function (PSF) limits the accuracy of this measurement procedure. We propose a model-based method that strongly reduces PSF-induced bias by incorporating the PSF into the thickness estimation method. We estimated the bias in thickness measurements in simulated thin sheet images as obtained from second derivative zero crossings. To gain insight into the range of sheet thickness where our method is expected to yield improved results, sheet thickness was varied between 0.15 and 1.2 mm with an assumed PSF as present in the high-resolution modes of current computed tomography (CT) scanners [full width at half maximum (FWHM) 0.5-0.8 mm]. Our model-based method was evaluated in practice by measuring layer thickness from CT images of a phantom mimicking two parallel cartilage layers in an arthrography procedure. CT arthrography images of cadaver wrists were also evaluated, and thickness estimates were compared to those obtained from high-resolution anatomical sections that served as a reference. The thickness estimates from the simulated images reveal that the method based on second derivative zero crossings shows considerable bias for layers in the submillimeter range. This bias is negligible for sheet thickness larger than 1 mm, where the size of the sheet is more than twice the FWHM of the PSF but can be as large as 0.2 mm for a 0.5 mm sheet. The results of the phantom experiments show that the bias is effectively reduced by our method. The deviations from the true thickness, due to random fluctuations induced by quantum noise in the CT images, are of the order of 3% for a standard wrist imaging protocol. In the wrist the submillimeter thickness estimates from the CT arthrography images correspond within 10% to those estimated from the anatomical

  3. Exploring Our Galaxy's Thick Disk

    Science.gov (United States)

    Kohler, Susanna

    2017-12-01

    What is the structure of the Milky Ways disk, and how did it form? A new study uses giant stars to explore these questions.A View from the InsideSchematic showing an edge-on, not-to-scale view of what we think the Milky Ways structurelookslike. The thick disk is shown in yellow and the thin disk is shown in green. [Gaba p]Spiral galaxies like ours are often observed to have disks consisting of two components: a thin disk that lies close to the galactic midplane, and a thick disk that extends above and below this. Past studies have suggested that the Milky Ways disk hosts the same structure, but our position embedded in the Milky Way makes this difficult to confirm.If we can measure the properties of a broad sample of distant tracer stars and use this to better understand the construction of the Milky Ways disk, then we can start to ask additional questions like, how did the disk components form? Formation pictures for the thick disk generally fall into two categories:Stars in the thick disk formed within the Milky Way either in situ or by migrating to their current locations.Stars in the thick disk formed in satellite galaxies around the Milky Way and then accreted when the satellites were disrupted.Scientists Chengdong Li and Gang Zhao (NAO Chinese Academy of Sciences, University of Chinese Academy of Sciences) have now used observations of giant stars which can be detected out to great distances due to their brightness to trace the properties of the Milky Ways thick disk and address the question of its origin.Best fits for the radial (top) and vertical (bottom) metallicity gradients of the thick-disk stars. [Adapted from Li Zhao 2017]Probing OriginsLi and Zhao used data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) in China to examine a sample of 35,000 giant stars. The authors sorted these stars into different disk components halo, thin disk, and thick disk based on their kinematic properties, and then explored how the orbital and

  4. Hexaferrite multiferroics: from bulk to thick films

    Science.gov (United States)

    Koutzarova, T.; Ghelev, Ch; Peneva, P.; Georgieva, B.; Kolev, S.; Vertruyen, B.; Closset, R.

    2018-03-01

    We report studies of the structural and microstructural properties of Sr3Co2Fe24O41 in bulk form and as thick films. The precursor powders for the bulk form were prepared following the sol-gel auto-combustion method. The prepared pellets were synthesized at 1200 °C to produce Sr3Co2Fe24O41. The XRD spectra of the bulks showed the characteristic peaks corresponding to the Z-type hexaferrite structure as a main phase and second phases of CoFe2O4 and Sr3Fe2O7-x. The microstructure analysis of the cross-section of the bulk pellets revealed a hexagonal sheet structure. Large areas were observed of packages of hexagonal sheets where the separate hexagonal particles were ordered along the c axis. Sr3Co2Fe24O41 thick films were deposited from a suspension containing the Sr3Co2Fe24O41 powder. The microstructural analysis of the thick films showed that the particles had the perfect hexagonal shape typical for hexaferrites.

  5. Disentangling The Thick Concept Argument

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2007-01-01

    Critics argue that non-cognitivism cannot adequately account for the existence and nature of some thick moral concepts. They use the existence of thick concepts as a lever in an argument against non-cognitivism, here called the Thick Concept Argument (TCA). While TCA is frequently invoked......, it is unfortunately rarely articulated. In this paper, TCA is first reconstructed on the basis of John McDowell’s formulation of the argument (from 1981), and then evaluated in the light of several possible non-cognitivist responses. In general, TCA assumes too much about what a non-cognitivist is (or must be......) committed to. There are several non-cognitivist theories, and only some fit the view attacked by TCA. Furthermore, TCA rests on a contestable intuition about a thought experiment, here called the External Standpoint Experiment (ESE). It is concluded that TCA is remarkably weak, given how frequently...

  6. Creep/fatigue damage prediction of fast reactor components using shakedown methods

    International Nuclear Information System (INIS)

    Buckthorpe, D.E.

    1997-01-01

    The present status of the shakedown method is reviewed, the application of the shakedown based principles to complex hardening and creep behaviour is described and justified and the prediction of damage against design criteria outlined. Comparisons are made with full inelastic analysis solutions where these are available and against damage assessments using elastic and inelastic design code methods. Current and future developments of the method are described including a summary of the advances made in the development of the post process ADAPT, which has enabled the method to be applied to complex geometry features and loading cases. The paper includes a review of applications of the method to typical Fast Reactor structural example cases within the primary and secondary circuits. For the primary circuit this includes structures such as the large diameter internal shells which are surrounded by hot sodium and subject to slow and rapid thermal transient loadings. One specific case is the damage assessment associated with thermal stratifications within sodium and the effects of moving sodium surfaces arising from reactor trip conditions. Other structures covered are geometric features within components such as the Above Core structure and Intermediate Heat Exchanger. For the secondary circuit the method has been applied to alternative and more complex forms of geometry namely thick section tubeplates of the Steam Generator and a typical secondary circuit piping run. Both of these applications are in an early stage of development but are expected to show significant advantages with respect to creep and fatigue damage estimation compared with existing code methods. The principle application of the method to design has so far been focused on Austenitic Stainless steel components however current work shows some significant benefits may be possible from the application of the method to structures made from Ferritic steels such as Modified 9Cr 1Mo. This aspect is briefly

  7. Are galaxy discs optically thick?

    International Nuclear Information System (INIS)

    Disney, Michael; Davies, Jonathan; Phillipps, Steven

    1989-01-01

    We re-examine the classical optical evidence for the low optical depths traditionally assigned to spiral discs and argue that it is highly model-dependent and unconvincing. In particular, layered models with a physically thin but optically thick dust layer behave like optically thin discs. The opposite hypotheses, that such discs are optically thick is then examined in the light of modern evidence. We find it to be consistent with the near-infrared and IRAS observations, with the surface brightnesses, with the HI and CO column densities and with the Hα measurements. (author)

  8. [Endoscopic full-thickness resection].

    Science.gov (United States)

    Meier, B; Schmidt, A; Caca, K

    2016-08-01

    Conventional endoscopic resection techniques such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are powerful tools for the treatment of gastrointestinal (GI) neoplasms. However, those techniques are limited to the superficial layers of the GI wall (mucosa and submucosa). Lesions without lifting sign (usually arising from deeper layers) or lesions in difficult anatomic positions (appendix, diverticulum) are difficult - if not impossible - to resect using conventional techniques, due to the increased risk of complications. For larger lesions (>2 cm), ESD appears to be superior to the conventional techniques because of the en bloc resection, but the procedure is technically challenging, time consuming, and associated with complications even in experienced hands. Since the development of the over-the-scope clips (OTSC), complications like bleeding or perforation can be endoscopically better managed. In recent years, different endoscopic full-thickness resection techniques came to the focus of interventional endoscopy. Since September 2014, the full-thickness resection device (FTRD) has the CE marking in Europe for full-thickness resection in the lower GI tract. Technically the device is based on the OTSC system and combines OTSC application and snare polypectomy in one step. This study shows all full-thickness resection techniques currently available, but clearly focuses on the experience with the FTRD in the lower GI tract.

  9. Effect of a Finite Trailing Edge Thickness on the Drag of Rectangular and Delta Wings at Supersonic Speeds

    National Research Council Canada - National Science Library

    Klunker, E

    1952-01-01

    The effect of a finite trailing-edge thickness on the pressure drag of rectangular and delta wings with truncated diamond-shaped airfoil sections with a given thickness ratio is studied for supersonic...

  10. Facial soft tissue thickness in North Indian adult population

    Directory of Open Access Journals (Sweden)

    Tanushri Saxena

    2012-01-01

    Full Text Available Objectives: Forensic facial reconstruction is an attempt to reproduce a likeness of facial features of an individual, based on characteristics of the skull, for the purpose of individual identification - The aim of this study was to determine the soft tissue thickness values of individuals of Bareilly population, Uttar Pradesh, India and to evaluate whether these values can help in forensic identification. Study design: A total of 40 individuals (19 males, 21 females were evaluated using spiral computed tomographic (CT scan with 2 mm slice thickness in axial sections and soft tissue thicknesses were measured at seven midfacial anthropological facial landmarks. Results: It was found that facial soft tissue thickness values decreased with age. Soft tissue thickness values were less in females than in males, except at ramus region. Comparing the left and right values in individuals it was found to be not significant. Conclusion: Soft tissue thickness values are an important factor in facial reconstruction and also help in forensic identification of an individual. CT scan gives a good representation of these values and hence is considered an important tool in facial reconstruction- This study has been conducted in North Indian population and further studies with larger sample size can surely add to the data regarding soft tissue thicknesses.

  11. Determination of accurate metal silicide layer thickness by RBS

    International Nuclear Information System (INIS)

    Kirchhoff, J.F.; Baumann, S.M.; Evans, C.; Ward, I.; Coveney, P.

    1995-01-01

    Rutherford Backscattering Spectrometry (RBS) is a proven useful analytical tool for determining compositional information of a wide variety of materials. One of the most widely utilized applications of RBS is the study of the composition of metal silicides (MSi x ), also referred to as polycides. A key quantity obtained from an analysis of a metal silicide is the ratio of silicon to metal (Si/M). Although compositional information is very reliable in these applications, determination of metal silicide layer thickness by RBS techniques can differ from true layer thicknesses by more than 40%. The cause of these differences lies in how the densities utilized in the RBS analysis are calculated. The standard RBS analysis software packages calculate layer densities by assuming each element's bulk densities weighted by the fractional atomic presence. This calculation causes large thickness discrepancies in metal silicide thicknesses because most films form into crystal structures with distinct densities. Assuming a constant layer density for a full spectrum of Si/M values for metal silicide samples improves layer thickness determination but ignores the underlying physics of the films. We will present results of RBS determination of the thickness various metal silicide films with a range of Si/M values using a physically accurate model for the calculation of layer densities. The thicknesses are compared to scanning electron microscopy (SEM) cross-section micrographs. We have also developed supporting software that incorporates these calculations into routine analyses. (orig.)

  12. Overweight is not associated with cortical thickness alterations in children

    Directory of Open Access Journals (Sweden)

    Rachel Jane Sharkey

    2015-02-01

    Full Text Available IntroductionSeveral studies report an association between body mass index (BMI and cortical thickness in adults. Some studies demonstrate diffuse cortical thinning in obesity, while others report effects in areas that are associated with self-regulation, such as lateral prefrontal cortex. MethodsThis study used multilevel modelling of data from the NIH Pediatric MRI Data Repository, a mixed longitudinal and cross-sectional database, to examine the relationship between cortical thickness and body weight in children. Cortical thickness was computed at 81,942 vertices of 716 MRI scans from 378 children aged between 4 and 18 years. Body mass index Z score for age was computed for each participant. We preformed vertex-wise statistical analysis of the relationship between cortical thickness and BMI, accounting for age and gender. In addition, cortical thickness was extracted from regions of interest in prefrontal cortex and insula.ResultsNo significant association between cortical thickness and BMI was found, either by statistical parametric mapping or by region of interest analysis. Results remained negative when the analysis was restricted to children aged 12-18.ConclusionsThe correlation between BMI and cortical thickness was not found in this large pediatric sample. The association between BMI and cortical thinning develops after adolescence. This has implications for the nature of the relationship between brain anatomy and weight gain.

  13. Measuring Rind Thickness on Polyurethane Foam

    Science.gov (United States)

    Johnson, C.; Miller, J.; Brown, H.

    1985-01-01

    Nondestructive test determines rind thickness of polyurethane foam. Surface harness of foam measured by Shore durometer method: hardness on Shore D scale correlates well with rind thickness. Shore D hardness of 20, for example, indicates rind thickness of 0.04 inch (1 millimeter). New hardness test makes it easy to determine rind thickness of sample nondestructively and to adjust fabrication variables accordingly.

  14. On thickness of Saturn rings

    International Nuclear Information System (INIS)

    Brahic, Andre; Laques, Pierre; Lecacheux, Jean; Servan, Bernard; Despiau, Raymond; Michet, Daniel; Renard, Leopold

    1980-01-01

    Electronographic plates of Saturn were taken during the transit of the Earth through the ring plane. Observing conditions were more favorable than those prevailing in 1966. Thanks to the quality of the detectors and the telescopes, it has been possible to make a more precise photometric determination of the brightness of the ring seen edge on and to measure the brightness variation with respect to the distance to the center of the planet. Extrapolating to the case where the elevation of the Earth above the ring plane is strictly zero, we deduce an apparent photometric ring thickness equal to 1.5+-0.3 km. For an homogeneous layer of small particles colliding inelastically, theory predicts a thickness of the order of a few particles radii, i.e. a few tens of meters. The observed brightness could be explained by the E ring, the brightness of large chunks, condensations and warping of the ring [fr

  15. Accurate thickness measurement of graphene

    International Nuclear Information System (INIS)

    Shearer, Cameron J; Slattery, Ashley D; Stapleton, Andrew J; Shapter, Joseph G; Gibson, Christopher T

    2016-01-01

    Graphene has emerged as a material with a vast variety of applications. The electronic, optical and mechanical properties of graphene are strongly influenced by the number of layers present in a sample. As a result, the dimensional characterization of graphene films is crucial, especially with the continued development of new synthesis methods and applications. A number of techniques exist to determine the thickness of graphene films including optical contrast, Raman scattering and scanning probe microscopy techniques. Atomic force microscopy (AFM), in particular, is used extensively since it provides three-dimensional images that enable the measurement of the lateral dimensions of graphene films as well as the thickness, and by extension the number of layers present. However, in the literature AFM has proven to be inaccurate with a wide range of measured values for single layer graphene thickness reported (between 0.4 and 1.7 nm). This discrepancy has been attributed to tip-surface interactions, image feedback settings and surface chemistry. In this work, we use standard and carbon nanotube modified AFM probes and a relatively new AFM imaging mode known as PeakForce tapping mode to establish a protocol that will allow users to accurately determine the thickness of graphene films. In particular, the error in measuring the first layer is reduced from 0.1–1.3 nm to 0.1–0.3 nm. Furthermore, in the process we establish that the graphene-substrate adsorbate layer and imaging force, in particular the pressure the tip exerts on the surface, are crucial components in the accurate measurement of graphene using AFM. These findings can be applied to other 2D materials. (paper)

  16. Soliton models for thick branes

    Energy Technology Data Exchange (ETDEWEB)

    Peyravi, Marzieh [Ferdowsi University of Mashhad, Department of Physics, School of Sciences, Mashhad (Iran, Islamic Republic of); Riazi, Nematollah [Shahid Beheshti University, Physics Department, Tehran (Iran, Islamic Republic of); Lobo, Francisco S.N. [Faculdade de Ciencias da Universidade de Lisboa, Instituto de Astrofisica e Ciencias do Espaco, Lisbon (Portugal)

    2016-05-15

    In this work, we present new soliton solutions for thick branes in 4+1 dimensions. In particular, we consider brane models based on the sine-Gordon (SG), φ{sup 4} and φ{sup 6} scalar fields, which have broken Z{sub 2} symmetry in some cases and are responsible for supporting and stabilizing the thick branes. The origin of the symmetry breaking in these models resides in the fact that the modified scalar field potential may have non-degenerate vacua. These vacua determine the cosmological constant on both sides of the brane. We also study the geodesic equations along the fifth dimension, in order to explore the particle motion in the neighborhood of the brane. Furthermore, we examine the stability of the thick branes, by determining the sign of the w{sup 2} term in the expansion of the potential for the resulting Schroedinger-like equation, where w is the five-dimensional coordinate. It turns out that the φ{sup 4} brane is stable, while there are unstable modes for certain ranges of the model parameters in the SG and φ{sup 6} branes. (orig.)

  17. Relationship between placental thickness and growth parameters in ...

    African Journals Online (AJOL)

    To investigate the relationship between placental thickness and foetal growth parameters in normal singleton Nigerian foetuses. Six hundred and sixty-six pregnant Nigerian women were studied by ultrasound in a cross sectional prospective study at the Federal Medical Centre, Makurdi, Nigeria. The pregnancies were in ...

  18. 49 CFR 178.345-2 - Material and material thickness.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Material and material thickness. 178.345-2 Section 178.345-2 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR...

  19. Variation in thickness of the large cryosections cut for whole-body autoradiography

    International Nuclear Information System (INIS)

    Ito, Tsunao; Brill, A.B.

    1991-01-01

    A method to assess variation in thickness of the large cryosections for whole-body autoradiography (WBARG) was described, and the degree of intraslice and interslice variations were determined for our cryomicrotome system (LKB PMV-2250). Intraslice variation in thickness of the 180 x 80 mm cryosection was 0.72-0.92 μm within the range of section thickness for WBARG (15-50 μm), and interslice variation was 0.89-1.21 μm. These potential variations in section thickness should be kept in mind whenever working with quantitative WBARG. (author)

  20. Generalized Joint Hypermobility Is Predictive of Hip Capsular Thickness.

    Science.gov (United States)

    Devitt, Brian M; Smith, Bjorn N; Stapf, Robert; Tacey, Mark; O'Donnell, John M

    2017-04-01

    The pathomechanics of hip microinstability are not clearly defined but are thought to involve anatomical abnormalities, repetitive forces across the hip, and ligamentous laxity. The purpose of this study was to explore the relationship between generalized joint hypermobility (GJH) and hip capsular thickness. The hypothesis was that GJH would be predictive of a thin hip capsule. Cross-sectional study; Level of evidence, 3. A prospective study was performed on 100 consecutive patients undergoing primary hip arthroscopy for the treatment of hip pain. A Beighton test score (BTS) was obtained prior to each procedure. The maximum score was 9, and a score of ≥4 was defined as hypermobile. Capsular thickness at the level of the anterior portal, corresponding to the location of the iliofemoral ligament, was measured arthroscopically using a calibrated probe. The presence of ligamentum teres (LT) pathology was also recorded. Fifty-five women and 45 men were included in the study. The mean age was 32 years (range, 18-45 years). The median hip capsule thickness was statistically greater in men than women (12.5 and 7.5 mm, respectively). The median BTS for men was 1 compared with 4 for women ( P BTS and capsular thickness; a BTS of BTS ≥4 correlates with a capsular thickness of BTS of ≥4 ( P BTS of BTS ≥4 correlates significantly with a thickness of <10 mm.

  1. Generalized Joint Hypermobility Is Predictive of Hip Capsular Thickness

    Science.gov (United States)

    Devitt, Brian M.; Smith, Bjorn N.; Stapf, Robert; Tacey, Mark; O’Donnell, John M.

    2017-01-01

    Background: The pathomechanics of hip microinstability are not clearly defined but are thought to involve anatomical abnormalities, repetitive forces across the hip, and ligamentous laxity. Purpose/Hypothesis: The purpose of this study was to explore the relationship between generalized joint hypermobility (GJH) and hip capsular thickness. The hypothesis was that GJH would be predictive of a thin hip capsule. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A prospective study was performed on 100 consecutive patients undergoing primary hip arthroscopy for the treatment of hip pain. A Beighton test score (BTS) was obtained prior to each procedure. The maximum score was 9, and a score of ≥4 was defined as hypermobile. Capsular thickness at the level of the anterior portal, corresponding to the location of the iliofemoral ligament, was measured arthroscopically using a calibrated probe. The presence of ligamentum teres (LT) pathology was also recorded. Results: Fifty-five women and 45 men were included in the study. The mean age was 32 years (range, 18-45 years). The median hip capsule thickness was statistically greater in men than women (12.5 and 7.5 mm, respectively). The median BTS for men was 1 compared with 4 for women (P hip capsular thickness. A BTS of <4 correlates significantly with a capsular thickness of ≥10 mm, while a BTS ≥4 correlates significantly with a thickness of <10 mm. PMID:28451620

  2. Cesarean Section

    Science.gov (United States)

    A Cesarean section (C-section) is surgery to deliver a baby. The baby is taken out through the mother's ... are able to have a vaginal birth after cesarean (VBAC). NIH: National Institute of Child Health and ...

  3. Thickness and uniformity measurements of nuclear targets

    International Nuclear Information System (INIS)

    Xu Guoji; Meng Xiangjin; Luo Xinghua; Guan Shouren

    1987-06-01

    This paper introduces the methods of target thickness and uniformity measurements including weighing, α-particle thickness gauge, quartz thickness gauge, optical transmittance and Rutherford backscattering. An α-particle gauging which measures target thicknesses up to several μm is metioned. A fast thickness measurements for C, Au and Cu targets by spectrophotometer is given. A high sensitive quartz gauge which can measure minimum deposit of 0.04 μg/cm 2 is described. Thickness and impurity determinations by RBS with accuracy better than 5% are summarized

  4. Non-contact radiation thickness gauge

    International Nuclear Information System (INIS)

    Tsujii, T.; Okino, T.

    1983-01-01

    A noncontact thickness gauge system for measuring the thickness of a material comprising a source of radiation, a detector for detecting the amount of radiation transmitted through the material which is a function of the absorptance and thickness of the material, a memory for storing the output signals of the detector and curve-defining parameters for a plurality of quadratic calibration curves which correspond to respective thickness ranges, and a processor for processing the signals and curve defining parameters to determine the thickness of the material. Measurements are made after precalibration to obtain calibration curves and these are stored in the memory, providing signals representative of a nominal thickness and an alloy compensation coefficient for the material. The calibration curve corresponding to a particular thickness range is selected and the curve compensated for drift; the material is inserted into the radiation path and the detector output signal processed with the compensated calibration curve to determine the thickness of the material. (author)

  5. Thickly Syndetical Sensitivity of Topological Dynamical System

    Directory of Open Access Journals (Sweden)

    Heng Liu

    2014-01-01

    Full Text Available Consider the surjective continuous map f:X→X, where X is a compact metric space. In this paper we give several stronger versions of sensitivity, such as thick sensitivity, syndetic sensitivity, thickly syndetic sensitivity, and strong sensitivity. We establish the following. (1 If (X,f is minimal and sensitive, then (X,f is syndetically sensitive. (2 Weak mixing implies thick sensitivity. (3 If (X,f is minimal and weakly mixing, then it is thickly syndetically sensitive. (4 If (X,f is a nonminimal M-system, then it is thickly syndetically sensitive. Devaney chaos implies thickly periodic sensitivity. (5 We give a syndetically sensitive system which is not thickly sensitive. (6 We give thickly syndetically sensitive examples but not cofinitely sensitive ones.

  6. Evaluation of the x-ray fluorescence method of precious metal plating thickness measurements. Technological spinoff report

    International Nuclear Information System (INIS)

    Carson, J.S.; Hearn, N.K.; Pettie, C.B.

    1975-09-01

    It is shown that gold and silver plating thickness measurements made using an x-ray spectrograph could be closely correlated with thicknesses measured from sectional samples. Good correlations were also shown for single overlays of gold over silver when each layer was less than 0.0003 inch thick

  7. doped ZnO thick film resistors

    Indian Academy of Sciences (India)

    The characterization and ethanol gas sensing properties of pure and doped ZnO thick films were investigated. Thick films of pure zinc oxide were prepared by the screen printing technique. Pure zinc oxide was almost insensitive to ethanol. Thick films of Al2O3 (1 wt%) doped ZnO were observed to be highly sensitive to ...

  8. Self-heating forecasting for thick laminates testing coupons in fatigue

    NARCIS (Netherlands)

    Lahuerta, F.; Westphal, T.; Nijssen, R.P.L.

    2012-01-01

    Thick laminate sections can be found from the tip to the root in most common wind turbine blade designs. Obtaining accurate and reliable design data for thick laminates is subject of investigations. Due to the poor thermal conductivity properties of composites and the material self-heating that

  9. Risk Factors and Consequences of Cortical Thickness in an Asian Population

    NARCIS (Netherlands)

    Hilal, S.; Xin, X.; Ang, S.L.; Tan, C.S.; Venketasubramanian, N.; Niessen, W.J.; Vrooman, H.; Wong, T.Y.; Chen, C.; Ikram, M.K.

    2015-01-01

    Cortical thickness has been suggested to be one of the most important markers of cortical atrophy. In this study, we examined potential risk factors of cortical thickness and its association with cognition in an elderly Asian population from Singapore. This is a cross-sectional study among 572

  10. Anatomical characterization of central, apical and minimal corneal thickness

    Directory of Open Access Journals (Sweden)

    Federico Saenz-Frances

    2014-08-01

    Full Text Available AIM: To anatomically locate the points of minimum corneal thickness and central corneal thickness (pupil center in relation to the corneal apex.METHODS: Observational, cross-sectional study, 299 healthy volunteers. Thickness at the corneal apex (AT, minimum corneal thickness (MT and corneal thickness at the pupil center (PT were determined using the pentacam. Distances from the corneal apex to MT (MD and PT (PD were calculated and their quadrant position (taking the corneal apex as the reference determined:point of minimum thickness (MC and point of central thickness (PC depending on the quadrant position. Two multivariate linear regression models were constructed to examine the influence of age, gender, power of the flattest and steepest corneal axes, position of the flattest axis, corneal volume (determined using the Pentacam and PT on MD and PD. The effects of these variables on MC and PC were also determined in two multinomial regression models.RESULTS: MT was located at a mean distance of 0.909 mm from the apex (79.4% in the inferior-temporal quadrant. PT was located at a mean distance of 0.156 mm from the apex. The linear regression model for MD indicated it was significantly influenced by corneal volume (B=-0.024; 95%CI:-0.043 to -0.004. No significant relations were identified in the linear regression model for PD or the multinomial logistic regressions for MC and PC.CONCLUSION: MT was typically located at the inferior-temporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume.

  11. Enamel thickness after preparation of tooth for porcelain laminate.

    Science.gov (United States)

    Pahlevan, Ayoub; Mirzaee, Mansoreh; Yassine, Esmaeil; Ranjbar Omrany, Ladan; Hasani Tabatabaee, Masumeh; Kermanshah, Hamid; Arami, Sakineh; Abbasi, Mehdy

    2014-07-01

    In this investigation the thickness of enamel in the gingival, middle, and incisal thirds of the labial surface of the anterior teeth were measured regarding preparation of the teeth for porcelain laminate veneers. Part one, 20 extracted intact human maxillary central and lateral incisors ten of each were selected. The teeth were imbedded in autopolimerize acrylic resin. Cross section was preformed through the midline of the incisal, middle and cervical one-third of the labial surface of the teeth. The samples were observed under reflected stereomicroscope and the thickness of enamel was recorded. Part II, the effect of different types of preparation on dentin exposure was evaluated. Thirty maxillary central incisor teeth were randomly divided into two groups: A: Knife-edge preparation. B: Chamfer preparation. All samples were embedded in autopolimerize acrylic resin using a silicon mold. The samples were cut through the midline of the teeth. The surface of the samples were polished and enamel and dentin were observed under the stereomicroscope. Data were analyzed by ANOVA-one way test. The results of this study showed that the least enamel thickness in the central incisor was 345 and in lateral incisor is 235 μ this thickness is related to the one-third labial cervical area. Maximum thickness in maxillary central and lateral incisors in the one-third labial incisal surface was 1260 μ and 1220μ, respectively. In the second part of the study, the tendency of dentinal exposure was shown with the chamfer preparation, but no dentinal exposure was found in the knife-edge preparation. The differences between groups were significant (p<0.05). The knowledge of enamel thickness in different part of labial surface is very important. The thickness of enamel in the gingival area does not permit a chamfer preparation. The knife edge preparation is preferable in gingival area.

  12. Enamel thickness after preparation of tooth for porcelain laminate.

    Directory of Open Access Journals (Sweden)

    Ayoub Pahlevan

    2014-08-01

    Full Text Available In this investigation the thickness of enamel in the gingival, middle, and incisal thirds of the labial surface of the anterior teeth were measured regarding preparation of the teeth for porcelain laminate veneers.Part one, 20 extracted intact human maxillary central and lateral incisors ten of each were selected. The teeth were imbedded in autopolimerize acrylic resin. Cross section was preformed through the midline of the incisal, middle and cervical one-third of the labial surface of the teeth. The samples were observed under reflected stereomicroscope and the thickness of enamel was recorded. Part II, the effect of different types of preparation on dentin exposure was evaluated. Thirty maxillary central incisor teeth were randomly divided into two groups: A: Knife-edge preparation. B: Chamfer preparation. All samples were embedded in autopolimerize acrylic resin using a silicon mold. The samples were cut through the midline of the teeth. The surface of the samples were polished and enamel and dentin were observed under the stereomicroscope.Data were analyzed by ANOVA-one way test. The results of this study showed that the least enamel thickness in the central incisor was 345 and in lateral incisor is 235 μ this thickness is related to the one-third labial cervical area. Maximum thickness in maxillary central and lateral incisors in the one-third labial incisal surface was 1260 μ and 1220μ, respectively. In the second part of the study, the tendency of dentinal exposure was shown with the chamfer preparation, but no dentinal exposure was found in the knife-edge preparation. The differences between groups were significant (p<0.05.The knowledge of enamel thickness in different part of labial surface is very important. The thickness of enamel in the gingival area does not permit a chamfer preparation. The knife edge preparation is preferable in gingival area.

  13. Smoking influences on the thickness of marginal gingival epithelium

    Directory of Open Access Journals (Sweden)

    Villar Cristina Cunha

    2003-01-01

    Full Text Available Smoking patients show reduction of inflammatory clinical signs that might be associated with local vasoconstriction and an increased gingival epithelial thickness. The purpose of this work was to evaluate the thickness of the marginal gingival oral epithelium in smokers and non-smokers, with clinically healthy gingivae or with gingivitis. Twenty biopsies were obtained from four different groups. Group I: non-smokers with clinically healthy gingivae (n = 5. Group II: non-smokers with gingivitis (n = 5. Group III: smokers with clinically healthy gingivae (n = 5. Group IV: smokers with gingivitis (n = 5. These biopsies were histologically processed, serially sectioned at 5 mm, stained with H. E., and examined by image analysis software (KS400, which was used to perform the morphometric evaluation and the quantification of the major epithelial thickness, the epithelial base thickness and the external and internal epithelial perimeters. Differences between the four groups were analyzed using ANOVA test and Tukey's test. The criteria for statistical significance were accepted at the probability level p < 0.05. A greater epithelial thickness was observed in smokers independent of the gingival health situation.

  14. Thick legs - not always lipedema.

    Science.gov (United States)

    Reich-Schupke, Stefanie; Altmeyer, Peter; Stücker, Markus

    2013-03-01

    Due to its increased presence in the press and on television, the diagnosis of lipedema is on the way to becoming a trendy diagnosis for those with thick legs. Despite this, one must recognize that lipedema is a very rare disease. It is characterized by disproportional obesity of the extremities, especially in the region of the hip and the legs, hematoma development after minimal trauma, and increased pressure-induced or spontaneous pain. Aids for making the correct diagnosis are (duplex) sonography, the waist-hip index or the waist-height index and lymphoscintigraphy. Important differential diagnoses are constitutional variability of the legs, lipohypertrophy in obesity, edema in immobility, edema in chronic venous insufficiency and rheumatic diseases. The symptom-based therapy of lipedema consists of conservative (compression, manual lymphatic drainage, exercise) and surgical treatments (liposuction). Until now there is no curative therapy. Obesity is an important risk factor for the severity and prognosis of lipedema. Further studies for a better understanding of the pathogenesis of lipedema and in the end possible curative treatments are urgently needed. © The Authors | Journal compilation © Blackwell Verlag GmbH, Berlin.

  15. Thickness of the Buccal Plate in Posterior Teeth: A Prospective Cone Beam Computed Tomography Study.

    Science.gov (United States)

    Temple, Kayleigh Eaves; Schoolfield, John; Noujeim, Marcel E; Huynh-Ba, Guy; Lasho, David J; Mealey, Brian L

    Buccal plate thickness is an important clinical parameter for postextraction implant treatment planning. The purpose of this study was to assess buccal plate thickness of the posterior maxilla and mandible using cone beam computed tomography (CBCT). A total of 265 patients and 934 teeth met the inclusion criteria for this study. CBCT volumes were taken and aligned for measurement at the ideal midsagittal cross-section. Buccal plate thickness was measured at 1, 3, and 5 mm apical to the alveolar crest. The frequency of thick (≥ 1 mm), thin (teeth.

  16. Evaluations of half-bead weld repair procedures with thick-wall pressure vessels

    International Nuclear Information System (INIS)

    Canonico, D.A.; Whitman, G.D.

    1978-01-01

    The results of research on the evaluation of the half-bead weld repair method for use on nuclear reactor components are reviewed from data obtained on thick-section test pieces and intermediate-size pressure vessels. Material properties, the magnitude of residual stresses and the structural behavior of flawed pressure vessels are being obtained to determine the adequacy of the weld repair method for application in thick-section components

  17. Three-dimensional reconstruction of enamel thickness and volume in humans and hominoids.

    Science.gov (United States)

    Gantt, David G; Kappleman, John; Ketcham, Richard A; Alder, Marden E; Deahl, Thomas H

    2006-05-01

    Enamel thickness is an important diagnostic characteristic in Hominoidea. However, the sample size is extremely small, relying upon mostly fractured specimens and a few sectioned specimens, providing an estimate of enamel thickness only. What is needed to fully understand the significance of enamel thickness is a non-destructive technique that is able to obtain the thickness, density, and volume of the dental hard tissues of large samples, thereby providing an accurate means of relating thickness, area, volume, and the pattern of distribution of both enamel and dentin. Investigators have attempted to circumvent this problem by developing a variety of indexes. However, we are still left with subjective descriptions, such as 'thin', 'thick', 'intermediate thick', and 'hyperthick'. The purpose of this investigation was therefore to demonstrate the ability of high-resolution X-ray computed microtomography (HRXCT), as a non-destructive method, to produce, accurately and reliably, contiguous slices revealing the thickness and area of enamel, dentin, and pulp chamber. Using imaging software, three-dimensional reconstructions were produced, which provided volume data for enamel and dentin. Three-dimensional reconstruction of HRXCT images provide, for the first time, the capability of accurately quantifying enamel and dentin thickness, distribution and volume, thereby eliminating the necessity of destructive thin-sectional analysis.

  18. Study on fluidity of squeeze cast AZ91D magnesium alloy with different wall thicknesses

    Directory of Open Access Journals (Sweden)

    Chen Yun

    2014-03-01

    Full Text Available Rectangular cross-section specimens with different section thicknesses were prepared to study the influences of pouring temperature, mould temperature and squeeze velocity on the fluidity of squeeze cast AZ91D magnesium alloy by means of orthogonal test design method. The results show that pouring temperature, mould temperature and squeeze velocity can significantly affect the fluidity of magnesium alloy specimens with wall thickness no more than 4 mm, and the pouring temperature is the most influential factor on the fluidity of specimens with wall thickness of 1, 2 and 3 mm, while mould temperature is the one for specimens with wall thickness of 4 mm. Increasing pouring temperature between 700 °C and 750 °C is beneficial to the fluidity of AZ91D magnesium alloy, and increasing mould temperature significantly enhances the filling ability of thick (3 and 4 mm section castings. The fluidity of squeeze cast magnesium alloy increases with the increase of wall thickness. It is not recommended to produce magnesium alloy casting with wall thickness of smaller than 3 mm by squeeze cast process due to the poor fluidity. The software DPS was used to generate the regression model, and linear regression equations of the fluidity of squeeze cast AZ91D with different wall thicknesses are obtained using the test results.

  19. Localizing gravity on exotic thick 3-branes

    International Nuclear Information System (INIS)

    Castillo-Felisola, Oscar; Melfo, Alejandra; Pantoja, Nelson; Ramirez, Alba

    2004-01-01

    We consider localization of gravity on thick branes with a nontrivial structure. Double walls that generalize the thick Randall-Sundrum solution, and asymmetric walls that arise from a Z 2 symmetric scalar potential, are considered. We present a new asymmetric solution: a thick brane interpolating between two AdS 5 spacetimes with different cosmological constants, which can be derived from a 'fake supergravity' superpotential, and show that it is possible to confine gravity on such branes

  20. Crown dimensions and proximal enamel thickness of mandibular second bicuspids

    Directory of Open Access Journals (Sweden)

    Sérgio Augusto Fernandes

    2011-08-01

    Full Text Available To achieve proper recontouring of anterior and posterior teeth, to obtain optimal morphology during enamel stripping, it is important to be aware of dental anatomy. This study aimed at evaluating crown dimensions and proximal enamel thickness in a sample of 40 extracted sound, human, mandibular, second bicuspids (20 right and 20 left. Mesiodistal, cervico-occlusal and buccolingual crown dimensions were measured using a digital caliper, accurate to 0.01 mm. Teeth were embedded in acrylic resin and cut along their long axes through the proximal surfaces to obtain 0.7 mm-thick central sections. Enamel thickness on the cut sections was measured using a perfilometer. Comparative analyses were carried out using the Student's-t test (α= 5%. The mean mesiodistal crown widths for right and left teeth were 7.79 mm (± 0.47 and 7.70 mm (± 0.51, respectively. Mean cervico-occlusal heights ranged from 8.31 mm (± 0.75 on the right to 8.38 mm (± 0.85 on the left teeth. The mean values for the buccolingual dimension were 8.67 mm (± 0.70 on the right and 8.65 mm (± 0.54 on the left teeth. The mean enamel thickness on the mesial surfaces ranged from 1.35 mm (± 0.22 to 1.40 mm (± 0.17, on the left and right sides, respectively. On the distal surfaces, the corresponding values were 1.44 mm (± 0.21 and 1.46 mm (± 0.12. No significant differences were found between measurements for right and left teeth. However, enamel thickness was significantly greater on the distal surfaces, compared with the mesial surfaces.

  1. Evaluation of thickness of CAD/CAM fabricated zirconia cores by digital microscope.

    Science.gov (United States)

    Habib, Syed Rashid; Otaibi, Asim Khaled Al; Anazi, Talal Ali Al; Anazi, Samer Mosleh Al

    2018-01-01

    Despite several advantages of digitalized workflow, researchers have noted discrepancies in the precision and trueness. This study investigated the accuracy in the final thickness of Zirconia (Zr) cores fabricated by five CAD/CAM systems. Standardized manufacturing of the cores with 1 mm thickness were carried out. Cores were then sectioned into two halves and measurement made with Digital Microscope at 5 points in micrometers. Overall, mean thickness for the groups was 1048.81 ± 94.01, which was 48 μm higher than the thickness programmed in the software. Anova showed a statistically significant difference between the groups (p= 0.000). Presence of variations in the thickness and 5 measurement points for the CAD/CAM systems investigated was found. No significant difference was observed and the thickness of the cores were within acceptable level.

  2. Card controlled beta backscatter thickness measuring instrument

    International Nuclear Information System (INIS)

    Schlesinger, J.

    1978-01-01

    An improved beta backscatter instrument for the nondestructive measurement of the thickness of thin coatings on a substrate is described. Included therein is the utilization of a bank of memory stored data representative of isotope, substrate, coating material and thickness range characteristics in association with a control card having predetermined indicia thereon selectively representative of a particular isotope, substrate material, coating material and thickness range for conditioning electronic circuit means by memory stored data selected in accord with the predetermined indicia on a control card for converting backscattered beta particle counts into indicia of coating thickness

  3. Cesarean Sections

    Science.gov (United States)

    ... time. They'll get smaller and become a natural skin color in the weeks and months after delivery. And because incisions are often made in the "bikini" area, many C-section scars aren't even noticeable. What If I Don't Feel Better? Call your health care provider if you have: a fever signs of ...

  4. Production of high thickness implanted layer

    International Nuclear Information System (INIS)

    Abdrashitov, V.G.; Ryzhov, V.V.; Turchanovskij, I.Yu.

    1987-01-01

    The possibilities of consecutive implantation and spray-coating method (CISC) for obtaining materials with implanted addition given profile were investigated. Taking nitrogen ions implantation as example, it is shown, that it is possible to control nitrogen distribution profile configuration by spray-coating of titanium layers with different thickness and by implantation dose change. Implanted layer thickness is determined by CISC cycle number

  5. ORIGINAL ARTICLE Sonographic gallbladder wall thickness in ...

    African Journals Online (AJOL)

    uniform agreement to use 3 mm as the upper limit for normal gallbladder wall thickness also applies to children.13,14 We would say that normal gallbladder wall thickness for most adults is ≤3 mm. Occasionally, even in normal subjects, the wall cannot be adequately measured, which may simply be due to the superficially ...

  6. Shell thickness effects on quantum dot brightness and energy transfer.

    Science.gov (United States)

    Chern, Margaret; Nguyen, Thuy T; Mahler, Andrew H; Dennis, Allison M

    2017-11-02

    Heterostructured core/shell quantum dots (QDs) are prized in biomedical imaging and biosensing applications because of their bright, photostable emission and effectiveness as Förster resonance energy transfer (FRET) donors. However, as nanomaterials chemistry has progressed beyond traditional QDs to incorporate new compositions, ultra-thick shells, and alloyed structures, few of these materials have had their optical properties systematically characterized for effective application. For example, thick-shelled QDs, also known as 'giant' QDs (gQDs) are useful in single-particle tracking microscopy because of their reduced blinking, but we know only that CdSe/CdS gQDs are qualitatively brighter than thin-shelled CdSe/CdS in aqueous media. In this study, we quantify the impact of shell thickness on the nanoparticle molar extinction coefficient, quantum yield, brightness, and effectiveness as a FRET donor for CdSe/xCdS core/shell and CdSe/xCdS/ZnS core/shell/shell QDs, with variable thicknesses of the CdS shell (x). Molar extinction coefficients up to three orders of magnitude higher than conventional dyes and forty-fold greater than traditional QDs are reported. When thick CdS shells are combined with ZnS capping, quantum yields following thiol ligand exchange reach nearly 40%-5-10× higher than either the commercially available QDs or gQDs without ZnS caps treated the same way. These results clearly show that thick CdS shells and ZnS capping shells work in concert to provide the brightest possible CdSe-based QDs for bioimaging applications. We demonstrate that thicker shelled gQDs are over 50-fold brighter than their thin-shelled counterparts because of significant increases in their absorption cross-sections and higher quantum yield in aqueous milieu. Consistent with the point-dipole approximation commonly used for QD-FRET, these data show that thick shells contribute to the donor-acceptor distance, reducing FRET efficiency. Despite the reduction in FRET efficiency

  7. Quantifying Local Thickness and Composition in Thin Films of Organic Photovoltaic Blends by Raman Scattering

    KAUST Repository

    Rodríguez-Martínez, Xabier

    2017-07-06

    We report a methodology based on Raman spectroscopy that enables the non-invasive and fast quantitative determination of local thickness and composition in thin films (from few monolayers to hundreds of nm) of one or more components. We apply our methodology to blends of organic conjugated materials relevant in the field of organic photovoltaics. As a first step, we exploit the transfer-matrix formalism to describe the Raman process in thin films including reabsorption and interference effects of the incoming and scattered electric fields. This allows determining the effective solid-state Raman cross-section of each material by studying the dependence of the Raman intensity on film thickness. These effective cross sections are then used to estimate the local thickness and composition in a series of polymer:fullerene blends. We find that the model is accurate within ±10 nm in thickness and ±5 vol% in composition provided that (i) the film thickness is kept below the thickness corresponding to the first maximum of the calculated Raman intensity oscillation; (ii) the materials making up the blend show close enough effective Raman cross-sections; and (iii) the degree of order attained by the conjugated polymer in the blend is similar to that achieved when cast alone. Our methodology opens the possibility to make quantitative maps of composition and thickness over large areas (from microns to centimetres squared) with diffraction-limited resolution and in any multi-component system based thin film technology.

  8. Macular thickness and macular volume measurements using spectral domain optical coherence tomography in normal Nepalese eyes

    Directory of Open Access Journals (Sweden)

    Pokharel A

    2016-03-01

    Full Text Available Amrit Pokharel,1 Gauri Shankar Shrestha,2 Jyoti Baba Shrestha2 1Department of Ophthalmology, Kathmandu Medical College Teaching Hospital, 2B P Koirala Lions Centre for Ophthalmic Studies, Institute of Medicine, Kathmandu, Nepal Purpose: To record the normative values for macular thickness and macular volume in normal Nepalese eyes. Methods: In all, 126 eyes of 63 emmetropic subjects (mean age: 21.17±6.76 years; range: 10–37 years were assessed for macular thickness and macular volume, using spectral domain-optical coherence tomography over 6×6 mm2 in the posterior pole. A fast macular thickness protocol was employed. Statistics such as the mean, median, standard deviation, percentiles, and range were used, while a P-value was set at 0.05 to test significance. Results: Average macular thickness and total macular volume were larger in males compared to females. With each year of increasing age, these variables decreased by 0.556 µm and 0.0156 mm3 for average macular thickness and total macular volume, respectively. The macular thickness was greatest in the inner superior section and lowest at the center of the fovea. The volume was greatest in the outer nasal section and thinnest in the fovea. The central subfield thickness (r=-0.243, P=0.055 and foveal volume (r=0.216, P=0.09 did not correlate with age. Conclusion: Males and females differ significantly with regard to macular thickness and macular volume measurements. Reports by other studies that the increase in axial length reduced thickness and volume, were negated by this study which found a positive correlation among axial length, thickness, and volume. Keywords: macular thickness, macular volume, optical coherence tomography, Nepal

  9. Mechanical Properties of Additively Manufactured Thick Honeycombs

    Directory of Open Access Journals (Sweden)

    Reza Hedayati

    2016-07-01

    Full Text Available Honeycombs resemble the structure of a number of natural and biological materials such as cancellous bone, wood, and cork. Thick honeycomb could be also used for energy absorption applications. Moreover, studying the mechanical behavior of honeycombs under in-plane loading could help understanding the mechanical behavior of more complex 3D tessellated structures such as porous biomaterials. In this paper, we study the mechanical behavior of thick honeycombs made using additive manufacturing techniques that allow for fabrication of honeycombs with arbitrary and precisely controlled thickness. Thick honeycombs with different wall thicknesses were produced from polylactic acid (PLA using fused deposition modelling, i.e., an additive manufacturing technique. The samples were mechanically tested in-plane under compression to determine their mechanical properties. We also obtained exact analytical solutions for the stiffness matrix of thick hexagonal honeycombs using both Euler-Bernoulli and Timoshenko beam theories. The stiffness matrix was then used to derive analytical relationships that describe the elastic modulus, yield stress, and Poisson’s ratio of thick honeycombs. Finite element models were also built for computational analysis of the mechanical behavior of thick honeycombs under compression. The mechanical properties obtained using our analytical relationships were compared with experimental observations and computational results as well as with analytical solutions available in the literature. It was found that the analytical solutions presented here are in good agreement with experimental and computational results even for very thick honeycombs, whereas the analytical solutions available in the literature show a large deviation from experimental observation, computational results, and our analytical solutions.

  10. Translucency of dental ceramics with different thicknesses.

    Science.gov (United States)

    Wang, Fu; Takahashi, Hidekazu; Iwasaki, Naohiko

    2013-07-01

    The increased use of esthetic restorations requires an improved understanding of the translucent characteristics of ceramic materials. Ceramic translucency has been considered to be dependent on composition and thickness, but less information is available about the translucent characteristics of these materials, especially at different thicknesses. The purpose of this study was to investigate the relationship between translucency and the thickness of different dental ceramics. Six disk-shaped specimens of 8 glass ceramics (IPS e.max Press HO, MO, LT, HT, IPS e.max CAD LT, MO, AvanteZ Dentin, and Trans) and 5 specimens of 5 zirconia ceramics (Cercon Base, Zenotec Zr Bridge, Lava Standard, Lava Standard FS3, and Lava Plus High Translucency) were prepared following the manufacturers' instructions and ground to a predetermined thickness with a grinding machine. A spectrophotometer was used to measure the translucency parameters (TP) of the glass ceramics, which ranged from 2.0 to 0.6 mm, and of the zirconia ceramics, which ranged from 1.0 to 0.4 mm. The relationship between the thickness and TP of each material was evaluated using a regression analysis (α=.05). The TP values of the glass ceramics ranged from 2.2 to 25.3 and the zirconia ceramics from 5.5 to 15.1. There was an increase in the TP with a decrease in thickness, but the amount of change was material dependent. An exponential relationship with statistical significance (Pceramics and zirconia ceramics. The translucency of dental ceramics was significantly influenced by both material and thickness. The translucency of all materials increased exponentially as the thickness decreased. All of the zirconia ceramics evaluated in the present study showed some degree of translucency, which was less sensitive to thickness compared to that of the glass ceramics. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  11. Mechanical Properties of Additively Manufactured Thick Honeycombs.

    Science.gov (United States)

    Hedayati, Reza; Sadighi, Mojtaba; Mohammadi Aghdam, Mohammad; Zadpoor, Amir Abbas

    2016-07-23

    Honeycombs resemble the structure of a number of natural and biological materials such as cancellous bone, wood, and cork. Thick honeycomb could be also used for energy absorption applications. Moreover, studying the mechanical behavior of honeycombs under in-plane loading could help understanding the mechanical behavior of more complex 3D tessellated structures such as porous biomaterials. In this paper, we study the mechanical behavior of thick honeycombs made using additive manufacturing techniques that allow for fabrication of honeycombs with arbitrary and precisely controlled thickness. Thick honeycombs with different wall thicknesses were produced from polylactic acid (PLA) using fused deposition modelling, i.e., an additive manufacturing technique. The samples were mechanically tested in-plane under compression to determine their mechanical properties. We also obtained exact analytical solutions for the stiffness matrix of thick hexagonal honeycombs using both Euler-Bernoulli and Timoshenko beam theories. The stiffness matrix was then used to derive analytical relationships that describe the elastic modulus, yield stress, and Poisson's ratio of thick honeycombs. Finite element models were also built for computational analysis of the mechanical behavior of thick honeycombs under compression. The mechanical properties obtained using our analytical relationships were compared with experimental observations and computational results as well as with analytical solutions available in the literature. It was found that the analytical solutions presented here are in good agreement with experimental and computational results even for very thick honeycombs, whereas the analytical solutions available in the literature show a large deviation from experimental observation, computational results, and our analytical solutions.

  12. Effect of boundary layer thickness on the flow characteristics around a rectangular prism

    International Nuclear Information System (INIS)

    Ji, Ho Seong; Kim, Kyung Chun

    2001-01-01

    Effect of boundary layer thickness on the flow characteristics around a rectangular prism has been investigated by using a PIV(Particle Image Velocimetry) technique. Three different boundary layers (thick, medium and thin) were generated in the atmospheric boundary layer wind tunnel at Pusan National University. The thick boundary layer having 670mm thickness was generated by using spires and roughness elements. The medium thickness of boundary layer(δ=270mm) was the natural turbulent boundary layer at the test section with fully long developing length(18m). The thin boundary layer with 36.5mm thickness was generated by on a smooth panel elevated 70cm from the wind tunnel floor. The Reynolds number based on the free stream velocity and the height of the model was 7.9X10 3 . The mean velocity vector fields and turbulent kinetic energy distribution were measured and compared. The effect of boundary layer thickness is clearly observed not only in the length of separation bubble but also in the reattachment points. The thinner boundary layer thickness, the higher turbulent kinetic energy peak around the model roof. It is strongly recommended that the height ratio between model and approaching boundary layer thickness should be a major parameter

  13. Macular thickness and volume in the elderly

    DEFF Research Database (Denmark)

    Subhi, Yousif; Forshaw, Thomas; Sørensen, Torben Lykke

    2016-01-01

    Ageing leads to a number of changes in the body including the macula. Detailed imaging using optical coherence tomography have enabled in vivo studies of how macula changes with age. Here we systematically review 49 studies (9115 participants and 11,577 eyes) to provide an overview of how ageing...... manifests in the macula of the elderly focusing on clinical relevant measures that are thicknesses and volumes of different macular areas. Ageing seems to increase center point foveal thickness. Ageing does not seem to change the center subfield thickness significantly. Ageing decreases the inner and outer...

  14. Film thickness determination by grazing incidence diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Battiston, G. A.; Gerbasi, R. [CNR, Padua (Italy). Istituto di Chimica e Tecnologie Inorganiche e dei Materiali Avanzati

    1996-09-01

    Thin films deposited via MOCVD (Metal Organic Chemical Vapour Deposition) are layers in the thickness range of a few manometers to about ten micrometers. An understanding of the physics and chemistry of films is necessary for a better comprehension of the phenomena involved in the film deposition procedure and its optimisation. Together with the crystalline phase a parameter that must be determined is the thickness of the layer. In this work the authors present a method for the measurement of the film thickness. This procedure, based on diffraction intensity absorption of the X-rays, both incident and diffracted in passing through the layers, resulted quite simple, rapid and non-destructive.

  15. Reappraising elastic thickness variation at oceanic trenches

    Science.gov (United States)

    Bry, Madeleine; White, Nicky

    2007-08-01

    We reassess the variation of elastic thickness as a function of lithospheric plate age using a global database of bathymetric and free-air gravity profiles which are perpendicular to oceanic trenches. As in many previous studies, our starting point is the well-known floating elastic plate model. In order to remove the influence of short-wavelength features not associated with lithospheric bending, adjacent profiles from 10-Myr bins have been stacked together to construct average profiles with standard deviations. Each average profile was then inverted in a two-stage procedure. First, singular value decomposition was used to determine two unknown flexural parameters, together with a regional slope and offset, for any given elastic thickness. This procedure was repeated for a range of elastic thicknesses. Second, residual misfit was plotted as a function of elastic thickness, and the global minimum was identified. This two-stage procedure makes no prior assumptions about magnitude of the load, size of the bending moment, or whether the elastic plate is broken/continuous. We obtained excellent fits between theory and observation for both bathymetric and gravity profiles from lithosphere with an age range of 0-150 Ma. The shape of the residual misfit function indicates the degree of confidence we have in our elastic thickness estimates. The lower limit of elastic thickness is usually well determined but upper limits are often poorly constrained. Inverse modeling was carried out using a range of profile lengths (250-300, 500, and 700 km). In general, our estimates show no consistent increase of elastic thickness as a function of plate age. This surprising result is consistent with recent reassessments of elastic thickness beneath seamounts and implies either that elastic thickness is independent of plate age or that elastic thickness cannot be measured with sufficient accuracy to reveal such a relationship. Modeling of short free-air gravity profiles (250-300 km) does

  16. Surface melting of deuterium hydride thick films

    OpenAIRE

    Zeppenfeld, P.; Bienfait, M.; Feng Chuan Liu,; Vilches, O.E.; Coddens, G.

    1990-01-01

    Quasi-elastic neutron scattering has been used to measure, below the bulk melting temperature, the thickness and the diffusion coefficient of the mobile surface layer of 8 and 10 layer thick films of deuterium hydride (HD) condensed on MgO(100). The measurements show that the close-packed surface of solid HD surface melts gradually, with the thickness of the melted layer increasing from 0.5 to 6 molecular layers as the temperature rises from 4 K to 0.05 K below the bulk melting temperature. T...

  17. Longitudinal changes in cortical thickness in autism and typical development

    Science.gov (United States)

    Prigge, Molly B. D.; Nielsen, Jared A.; Froehlich, Alyson L.; Abildskov, Tracy J.; Anderson, Jeffrey S.; Fletcher, P. Thomas; Zygmunt, Kristen M.; Travers, Brittany G.; Lange, Nicholas; Alexander, Andrew L.; Bigler, Erin D.; Lainhart, Janet E.

    2014-01-01

    The natural history of brain growth in autism spectrum disorders remains unclear. Cross-sectional studies have identified regional abnormalities in brain volume and cortical thickness in autism, although substantial discrepancies have been reported. Preliminary longitudinal studies using two time points and small samples have identified specific regional differences in cortical thickness in the disorder. To clarify age-related trajectories of cortical development, we examined longitudinal changes in cortical thickness within a large mixed cross-sectional and longitudinal sample of autistic subjects and age- and gender-matched typically developing controls. Three hundred and forty-five magnetic resonance imaging scans were examined from 97 males with autism (mean age = 16.8 years; range 3–36 years) and 60 males with typical development (mean age = 18 years; range 4–39 years), with an average interscan interval of 2.6 years. FreeSurfer image analysis software was used to parcellate the cortex into 34 regions of interest per hemisphere and to calculate mean cortical thickness for each region. Longitudinal linear mixed effects models were used to further characterize these findings and identify regions with between-group differences in longitudinal age-related trajectories. Using mean age at time of first scan as a reference (15 years), differences were observed in bilateral inferior frontal gyrus, pars opercularis and pars triangularis, right caudal middle frontal and left rostral middle frontal regions, and left frontal pole. However, group differences in cortical thickness varied by developmental stage, and were influenced by IQ. Differences in age-related trajectories emerged in bilateral parietal and occipital regions (postcentral gyrus, cuneus, lingual gyrus, pericalcarine cortex), left frontal regions (pars opercularis, rostral middle frontal and frontal pole), left supramarginal gyrus, and right transverse temporal gyrus, superior parietal lobule, and

  18. Longitudinal changes in cortical thickness in autism and typical development.

    Science.gov (United States)

    Zielinski, Brandon A; Prigge, Molly B D; Nielsen, Jared A; Froehlich, Alyson L; Abildskov, Tracy J; Anderson, Jeffrey S; Fletcher, P Thomas; Zygmunt, Kristen M; Travers, Brittany G; Lange, Nicholas; Alexander, Andrew L; Bigler, Erin D; Lainhart, Janet E

    2014-06-01

    The natural history of brain growth in autism spectrum disorders remains unclear. Cross-sectional studies have identified regional abnormalities in brain volume and cortical thickness in autism, although substantial discrepancies have been reported. Preliminary longitudinal studies using two time points and small samples have identified specific regional differences in cortical thickness in the disorder. To clarify age-related trajectories of cortical development, we examined longitudinal changes in cortical thickness within a large mixed cross-sectional and longitudinal sample of autistic subjects and age- and gender-matched typically developing controls. Three hundred and forty-five magnetic resonance imaging scans were examined from 97 males with autism (mean age = 16.8 years; range 3-36 years) and 60 males with typical development (mean age = 18 years; range 4-39 years), with an average interscan interval of 2.6 years. FreeSurfer image analysis software was used to parcellate the cortex into 34 regions of interest per hemisphere and to calculate mean cortical thickness for each region. Longitudinal linear mixed effects models were used to further characterize these findings and identify regions with between-group differences in longitudinal age-related trajectories. Using mean age at time of first scan as a reference (15 years), differences were observed in bilateral inferior frontal gyrus, pars opercularis and pars triangularis, right caudal middle frontal and left rostral middle frontal regions, and left frontal pole. However, group differences in cortical thickness varied by developmental stage, and were influenced by IQ. Differences in age-related trajectories emerged in bilateral parietal and occipital regions (postcentral gyrus, cuneus, lingual gyrus, pericalcarine cortex), left frontal regions (pars opercularis, rostral middle frontal and frontal pole), left supramarginal gyrus, and right transverse temporal gyrus, superior parietal lobule, and

  19. Wide band interferometry for thickness measurement

    Science.gov (United States)

    Costantino, Santiago; Martinez, Oscar E.; Torga, Jorge R.

    2003-04-01

    In this work we present the concept of wide band interferometry as opposed to white-light interferometry to introduce a thickness measurement method that gains precision when the bandwidth is reduced to an adequate compromise in order to avoid the distortions arising from the material dispersion. The use of the widest possible band is a well established dogma when the highest resolution is desired in distance measurements with white-light interferometry. We will show that the dogma falls when thickness measurements must be carried out due to material dispersion. In fact the precise knowledge of the frequency dependence of the refractive index is essential for adequate thickness retrieval from the optical experiments. The device we present is also useful to obtain the group refractive index that is necessary to calculate the absolute thickness value. As an example, we show the spreading of a silicone oil on a reference surface in real time.

  20. Russian River Ice Thickness and Duration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of river ice thickness measurements, and beginning and ending dates for river freeze-up events from fifty stations in northern Russia. The...

  1. Eddy current technologies for thick metal structures

    International Nuclear Information System (INIS)

    Takagi, Toshiyuki; Endo, Hisashi

    2004-01-01

    One of approach of an eddy current testing (ECT) for thick metal structures is introduced. The detection limit of ECT is capable of enlarging thick more than 10 mm, which is ordinarily about 5 mm, by the design of probe. On the basis of results of numerical analysis, the defect detection in thick and shape is evaluated by the distribution of experimental ECT signals. The problems of ECT for thick metal structures and measures, approach to probe design, the specifications of probe, evaluation of experimental results and defect detection are described. By ECT fast simulator, good slit sharp is simulated in the case of 10 and 20 mm of EDM slit length and 5, 10 and 15 mm of slit height. (S.Y.)

  2. Climate stability and cloud optical thickness feedbacks

    Science.gov (United States)

    Somerville, Richard C. J.; Iacobellis, Sam

    1989-01-01

    An improved radiative-convective model (RCM) has been developed and used to examine the role of cirrus clouds in the optical thickness feedback mechanism. Low and middle clouds are approximately black bodies for infrared radiative transfer, and so any increase in their optical thickness primarily increases the cloud albedo. Thus, if a climate warming is accompanied by an increase in average atmospheric absolute humidity and hence in average cloud liquid water content, low and middle cloud optical thickness and albedo may increase. The result is a negative feedback on the climate change, tending to reduce the surface temperature increase. Recent research suggests that the optical thickness feedback can depend sensitively on aspects of cirrus which are not well observed or adequately incorporated in typical present-day climate models.

  3. Greenland Radar Ice Sheet Thickness Measurements

    Data.gov (United States)

    National Aeronautics and Space Administration — Two 150-MHz coherent radar depth sounders were developed and flown over the Greenland ice sheet to obtain ice thickness measurements in support of PARCA...

  4. Model SH intelligent instrument for thickness measuring

    International Nuclear Information System (INIS)

    Liu Juntao; Jia Weizhuang; Zhao Yunlong

    1995-01-01

    The authors introduce Model SH Intelligent Instrument for thickness measuring by using principle of beta back-scattering and its application range, features, principle of operation, system design, calibration and specifications

  5. Arctic Sea Ice Freeboard and Thickness

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides measurements of sea ice freeboard and sea ice thickness for the Arctic region. The data were derived from measurements made by from the Ice,...

  6. A database of worldwide glacier thickness observations

    DEFF Research Database (Denmark)

    Gärtner-Roer, I.; Naegeli, K.; Huss, M.

    2014-01-01

    surface observations. However, although thickness has been observed on many glaciers and ice caps around the globe, it has not yet been published in the shape of a readily available database. Here, we present a standardized database of glacier thickness observations compiled by an extensive literature...... review and from airborne data extracted from NASA's Operation IceBridge. This database contains ice thickness observations from roughly 1100 glaciers and ice caps including 550 glacier-wide estimates and 750,000 point observations. A comparison of these observational ice thicknesses with results from...... area- and slope-dependent approaches reveals large deviations both from the observations and between different estimation approaches. For glaciers and ice caps all estimation approaches show a tendency to overestimation. For glaciers the median relative absolute deviation lies around 30% when analyzing...

  7. APPLIED ORIGAMI. Origami of thick panels.

    Science.gov (United States)

    Chen, Yan; Peng, Rui; You, Zhong

    2015-07-24

    Origami patterns, including the rigid origami patterns in which flat inflexible sheets are joined by creases, are primarily created for zero-thickness sheets. In order to apply them to fold structures such as roofs, solar panels, and space mirrors, for which thickness cannot be disregarded, various methods have been suggested. However, they generally involve adding materials to or offsetting panels away from the idealized sheet without altering the kinematic model used to simulate folding. We develop a comprehensive kinematic synthesis for rigid origami of thick panels that differs from the existing kinematic model but is capable of reproducing motions identical to that of zero-thickness origami. The approach, proven to be effective for typical origami, can be readily applied to fold real engineering structures. Copyright © 2015, American Association for the Advancement of Science.

  8. Serum Levels of Anticyclic Citrullinated Peptide Antibodies, Interleukin-6, Tumor Necrosis Factor-α, and C-Reactive Protein Are Associated with Increased Carotid Intima-Media Thickness: A Cross-Sectional Analysis of a Cohort of Rheumatoid Arthritis Patients without Cardiovascular Risk Factors

    Science.gov (United States)

    Vázquez-Del Mercado, Mónica; Nuñez-Atahualpa, Lourdes; Figueroa-Sánchez, Mauricio; Gómez-Bañuelos, Eduardo; Rocha-Muñoz, Alberto Daniel; Martín-Márquez, Beatriz Teresita; Martínez-García, Erika Aurora; Macias-Reyes, Héctor; Gamez-Nava, Jorge Ivan; Navarro-Hernandez, Rosa Elena; Nuñez-Atahualpa, María Alejandra; Andrade-Garduño, Javier

    2015-01-01

    The main cause of death in rheumatoid arthritis (RA) is cardiovascular events. We evaluated the relationship of anticyclic citrullinated peptide (anti-CCP) antibody levels with increased carotid intima-media thickness (cIMT) in RA patients. Methods. Forty-five anti-CCP positive and 37 anti-CCP negative RA patients, and 62 healthy controls (HC) were studied. All groups were assessed for atherogenic index of plasma (AIP) and cIMT. Anti-CCP, C-reactive protein (CRP), and levels of tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). Results. The anti-CCP positive RA patients showed increased cIMT compared to HC and anti-CCP negative (P < 0.001). Anti-CCP positive versus anti-CCP negative RA patients, had increased AIP, TNFα and IL-6 (P < 0.01), and lower levels of high density lipoprotein cholesterol (HDL-c) (P = 0.02). The cIMT correlated with levels of anti-CCP (r = 0.513, P = 0.001), CRP (r = 0.799, P < 0.001), TNFα (r = 0.642, P = 0.001), and IL-6 (r = 0.751, P < 0.001). In multiple regression analysis, cIMT was associated with CRP (P < 0.001) and anti-CCP levels (P = 0.03). Conclusions. Levels of anti-CCP and CRP are associated with increased cIMT and cardiovascular risk supporting a clinical role of the measurement of cIMT in RA in predicting and preventing cardiovascular events. PMID:25821796

  9. Serum Levels of Anticyclic Citrullinated Peptide Antibodies, Interleukin-6, Tumor Necrosis Factor-α, and C-Reactive Protein Are Associated with Increased Carotid Intima-Media Thickness: A Cross-Sectional Analysis of a Cohort of Rheumatoid Arthritis Patients without Cardiovascular Risk Factors

    Directory of Open Access Journals (Sweden)

    Mónica Vázquez-Del Mercado

    2015-01-01

    Full Text Available The main cause of death in rheumatoid arthritis (RA is cardiovascular events. We evaluated the relationship of anticyclic citrullinated peptide (anti-CCP antibody levels with increased carotid intima-media thickness (cIMT in RA patients. Methods. Forty-five anti-CCP positive and 37 anti-CCP negative RA patients, and 62 healthy controls (HC were studied. All groups were assessed for atherogenic index of plasma (AIP and cIMT. Anti-CCP, C-reactive protein (CRP, and levels of tumor necrosis factor alpha (TNFα and interleukin-6 (IL-6 were measured by enzyme-linked immunosorbent assay (ELISA. Results. The anti-CCP positive RA patients showed increased cIMT compared to HC and anti-CCP negative (P<0.001. Anti-CCP positive versus anti-CCP negative RA patients, had increased AIP, TNFα and IL-6 (P<0.01, and lower levels of high density lipoprotein cholesterol (HDL-c (P=0.02. The cIMT correlated with levels of anti-CCP (r=0.513, P=0.001, CRP (r=0.799, P<0.001, TNFα (r=0.642, P=0.001, and IL-6 (r=0.751, P<0.001. In multiple regression analysis, cIMT was associated with CRP (P<0.001 and anti-CCP levels (P=0.03. Conclusions. Levels of anti-CCP and CRP are associated with increased cIMT and cardiovascular risk supporting a clinical role of the measurement of cIMT in RA in predicting and preventing cardiovascular events.

  10. Techniques for sectioning alpha-contaminated equipment

    International Nuclear Information System (INIS)

    Arrowsmith, H.W.; Allen, R.P.; Fetrow, L.K.

    1981-01-01

    This paper summarizes work conducted at Pacific Northwest Laboratory (PNL) to develop, adapt and evaluate a variety of techniques for the sectioning and disassembly of glove boxes, chemical processing equipment, pipes, ducts and other components contaminated with plutonium or other alpha emitters. A unique sectioning facility equipped with glove ports, master slave manipulators, a bridge crane and a personnel air lock has been installed and is now operational. This facility is used as a work space where a variety of sectioning techniques are compared with respect to (1) effectiveness, (2) ability to accommodate a variety of geometries, (3) waste generation and (4) ease of adaption for remote operation. Sectioning techniques currently being evaluated include dry and wet plasma torch cutting, hydraulic shearing and mechanical cutting. A dry hand-held plasma torch capable of cutting 0.6-cm-thick stainless steel at the rate of 100 cm/min and material up to 2.5 cm thick at a slower rate is currently being used to section glove boxes and equipment contaminated with plutonium. A water-injected, water-muffled plasma arc torch is currently being modified for installation in the sectioning facility. This torch can cut 0.6-cm thick stainless steel at the rate of 400 cm/min and material up to 16 cm thick at slower rates. The water-injected torch is expected to solve many of the problems associated with the dry plasma arc torch. Mechanical sectioning techniques being evaluated include a hydraulic shear capable of rapidly shearing a stainless steel sheet 23 cm wide x 0.5 cm thick. The advantage of shearing as a sectioning technique is that all the waste products generated can be decontaminated using vibratory finishing or electropolishing techniques and that almost no contamination is entrapped in the sheared edge. Other mechanical techniques being evaluated include mechanical nibblers, reciprocating saws and pipe-sectioning equipment

  11. Rifting Thick Lithosphere - Canning Basin, Western Australia

    Science.gov (United States)

    Czarnota, Karol; White, Nicky

    2016-04-01

    The subsidence histories and architecture of most, but not all, rift basins are elegantly explained by extension of ~120 km thick lithosphere followed by thermal re-thickening of the lithospheric mantle to its pre-rift thickness. Although this well-established model underpins most basin analysis, it is unclear whether the model explains the subsidence of rift basins developed over substantially thick lithosphere (as imaged by seismic tomography beneath substantial portions of the continents). The Canning Basin of Western Australia is an example where a rift basin putatively overlies lithosphere ≥180 km thick, imaged using shear wave tomography. Subsidence modelling in this study shows that the entire subsidence history of the account for the observed subsidence, at standard crustal densities, the lithospheric mantle is required to be depleted in density by 50-70 kg m-3, which is in line with estimates derived from modelling rare-earth element concentrations of the ~20 Ma lamproites and global isostatic considerations. Together, these results suggest that thick lithosphere thinned to > 120 km is thermally stable and is not accompanied by post-rift thermal subsidence driven by thermal re-thickening of the lithospheric mantle. Our results show that variations in lithospheric thickness place a fundamental control on basin architecture. The discrepancy between estimates of lithospheric thickness derived from subsidence data for the western Canning Basin and those derived from shear wave tomography suggests that the latter technique currently is limited in its ability to resolve lithospheric thickness variations at horizontal half-wavelength scales of <300 km.

  12. Phase Space Exchange in Thick Wedge Absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, David [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2017-01-01

    The problem of phase space exchange in wedge absorbers with ionization cooling is discussed. The wedge absorber exchanges transverse and longitudinal phase space by introducing a position-dependent energy loss. In this paper we note that the wedges used with ionization cooling are relatively thick, so that single wedges cause relatively large changes in beam phase space. Calculation methods adapted to such “thick wedge” cases are presented, and beam phase-space transformations through such wedges are discussed.

  13. Crustal thickness variations in northern Morocco

    Science.gov (United States)

    Mancilla, Flor de Lis; Stich, Daniel; Morales, José; Julià, Jordi; Diaz, Jordi; Pazos, Antonio; Córdoba, Diego; Pulgar, Javier A.; Ibarra, Pedro; Harnafi, Mimoun; Gonzalez-Lodeiro, Francisco

    2012-02-01

    During the TopoIberia experiment, a total of 26 seismic broadband stations were recording in northern Morocco, providing for the first time extended regional coverage for investigating structure and seismotectonics of the southern branch of the Betic-Rif arc, its foreland, and the Atlas domain. Here, we analyze P-to-S converted waves in teleseismic receiver functions to infer gross crustal properties as thickness and Vp/Vs ratio. Strong lateral variations of the crustal thickness are observed throughout the region. Crustal thicknesses vary between 22 and 44 km and display a simple geographic pattern that divides the study area into three domains: entire northwestern Morocco underlain by a thickened crust with crustal thicknesses between 35 and 44 km; northeastern Morocco affected by significant crustal thinning, with crustal thicknesses ranging from 22 to 30 km, with the shallowest Moho along the Mediterranean coast; and an extended domain of 27-34 km thick crust, farther south which includes the Atlas domain and its foreland regions. Vp/Vs ratios show normal values of ˜1.75 for most stations except for the Atlas domain, where several stations give low Vp/Vs ratios of around 1.71. The very sharp transition from thick crust in northwestern Morocco to thin crust in northeastern Morocco is attributed to regional geodynamics, possibly the realm of present-day subcrustal dynamics in the final stage of western Mediterranean subduction. Crustal thicknesses just slightly above 30 km in the southern domain are intriguing, showing that high topography in this region is not isostatically compensated at crustal level.

  14. Versatile technique for assessing thickness of 2D layered materials by XPS

    Science.gov (United States)

    Zemlyanov, Dmitry Y.; Jespersen, Michael; Zakharov, Dmitry N.; Hu, Jianjun; Paul, Rajib; Kumar, Anurag; Pacley, Shanee; Glavin, Nicholas; Saenz, David; Smith, Kyle C.; Fisher, Timothy S.; Voevodin, Andrey A.

    2018-03-01

    X-ray photoelectron spectroscopy (XPS) has been utilized as a versatile method for thickness characterization of various two-dimensional (2D) films. Accurate thickness can be measured simultaneously while acquiring XPS data for chemical characterization of 2D films having thickness up to approximately 10 nm. For validating the developed technique, thicknesses of few-layer graphene (FLG), MoS2 and amorphous boron nitride (a-BN) layer, produced by microwave plasma chemical vapor deposition (MPCVD), plasma enhanced chemical vapor deposition (PECVD), and pulsed laser deposition (PLD) respectively, were accurately measured. The intensity ratio between photoemission peaks recorded for the films (C 1s, Mo 3d, B 1s) and the substrates (Cu 2p, Al 2p, Si 2p) is the primary input parameter for thickness calculation, in addition to the atomic densities of the substrate and the film, and the corresponding electron attenuation length (EAL). The XPS data was used with a proposed model for thickness calculations, which was verified by cross-sectional transmission electron microscope (TEM) measurement of thickness for all the films. The XPS method determines thickness values averaged over an analysis area which is orders of magnitude larger than the typical area in cross-sectional TEM imaging, hence provides an advanced approach for thickness measurement over large areas of 2D materials. The study confirms that the versatile XPS method allows rapid and reliable assessment of the 2D material thickness and this method can facilitate in tailoring growth conditions for producing very thin 2D materials effectively over a large area. Furthermore, the XPS measurement for a typical 2D material is non-destructive and does not require special sample preparation. Therefore, after XPS analysis, exactly the same sample can undergo further processing or utilization.

  15. Assessment of the accuracy of dental enamel thickness measurements using microfocal X-ray computed tomography.

    Science.gov (United States)

    Olejniczak, Anthony J; Grine, Frederick E

    2006-03-01

    Tooth enamel thickness has long been an important character in studies of primate and especially hominin phylogeny, taxonomy, and adaptation. Current methods for accurately assessing enamel thickness involve the physical sectioning of teeth, because measurements of enamel thickness using some radiographic techniques are unreliable. However, because destructive methods limit sample sizes and access to important fossil specimens, it is desirable that they be replaced with nondestructive techniques. Although microfocal X-ray computed tomography (mCT) has been used recently in studies of enamel thickness, the accuracy of this technique has yet to be established. The present research compares physical sections to computer-generated mCT sections of teeth from a variety of primate and nonprimate, recent and fossil taxa to examine whether enamel thickness, tooth size, and diagenetic remineralization (fossilization) impact the ability of mCT to measure enamel thickness accurately. Results indicate that recent teeth of varying size and thickness are clearly and accurately depicted in mCT scans, with measurements from nearly identical planes in physical and mCT sections differing by 3-5%. A fossil papionin molar (ca. 2 Myr) was also accurately measured using mCT scans, although thinner enamel in much older therapsid (ca. 263-241 Myr) teeth could not be distinguished from dentine. mCT is thus an accurate technique for measuring enamel thickness in recent taxa, although heavily mineralized teeth pose an obstacle to the ability of mCT to distinguish dental tissues. Moreover, absolutely thin enamel (less than approximately 0.10 mm) is difficult to resolve adequately in raw mCT images based on pixel values alone. Therefore, caution must be exercised in the application of mCT to the study of fossilized teeth.

  16. Thick skin and cosmetic surgery of the nasal tip: how to avoid the cutaneous polly beak.

    Science.gov (United States)

    Botti, G

    1996-01-01

    Although thick skin is generally considered a disadvantage in cosmetic surgery of the nasal tip, responsible for the supra tip deformity known as "polly beak" and other aesthetic defects, there are surgical guidelines that can greatly reduce the occurrence of these problems, the most interesting of which is grafting. On the contrary, thick skin could even be considered an advantage, if it masks amputated cartilaginous margins following any dome-sectioning technique.

  17. The influence of product thickness on the measurements by Barkhausen Noise method

    OpenAIRE

    T. Garstka

    2008-01-01

    Purpose: The aim of this paper is to show how varying cross section thickness of tested product and calibration sample can depend on results of the residual stress measurements by the Barkhausen Noise method.Design/methodology/approach: The Barkhausen noise parameters as RMS value and total number of Barkhausen pulses in samples with different thickness was measured and compared. Also influence of the frequency and intensity of the magnetization current was analysing.Findings: The significant...

  18. Use of B-mode ultrasonography for measuring femoral muscle thickness in dogs

    Science.gov (United States)

    SAKAEDA, Kanako; SHIMIZU, Miki

    2016-01-01

    Assessment of muscle mass is important for evaluating muscle function and rehabilitation outcomes. Ultrasound has recently been successfully used to estimate muscle mass in humans by measuring muscle thickness. This study attempted to standardize procedures for measuring femoral muscle thickness ultrasonographically, as well as quantify the reliability and validity of ultrasound evaluations of muscle thickness compared to measurements made by magnetic resonance imaging (MRI) in dogs. We evaluated the quadriceps femoris (QF), biceps femoris (BF), semitendinosus (ST) and semimembranosus (SM) muscles of 10 clinically healthy Beagle dogs. Scans were taken in 5 different sections divided equally between the greater trochanter and proximal patella. MRI was performed, followed by T1-weighted and contrast-enhanced T1-weighted imaging. Muscle cross-sectional area (CSA) was measured with MRI, and muscle thickness was measured with MRI and ultrasonography. The thickness of the QF, BF and ST muscles as measured by ultrasound at slices 1–3 (from the proximal end to the middle of the femur), 2–4 (middle of the femur) and 2 (more proximal than the middle of the femur), respectively, was correlated with muscle thickness and CSA as measured by MRI. These sites showed a flat interface between muscle and transducer and were situated over belly muscle. No correlation between measurement types was seen in SM muscle. We must confirm this assessment method for various breeds, sizes, ages and muscle pathologies in dogs, thereby confirming that muscle thickness as measured ultrasonographically can reflect muscle function. PMID:26832997

  19. The thick-bedded tail of turbidite thickness distribution as a proxy for flow confinement: Examples from tertiary basins of central and northern Apennines (Italy)

    Science.gov (United States)

    Marini, Mattia; Felletti, Fabrizio; Milli, Salvatore; Patacci, Marco

    2016-07-01

    This study reviews the thickness statistics of non-channelized turbidites from four tertiary basins of Central-Northern Apennines (Italy), where bed geometry and sedimentary character have been previously assessed. Though very different in terms of size and, arguably, character of feeder system, these basins share a common stratigraphic evolution consisting in transition from an early ponded to a late unconfined setting of deposition. Based on comparison of thickness subsets from diverse locations and stratigraphic heights within the studied turbidite fills, this paper seeks to answer the following questions: i) how data collection procedures and field operational constraints (e.g. measure location, outcrop quality, use of thicknesses data from single vs. multiple correlative sections, stratigraphic thickness of the study interval) can affect statistics of sample data? ii) how depositional controls of confined vs. unconfined turbidite basins can result in different thickness-frequency distributions?; and iii) is there in thickness statistics a 'flow confinement' signature which can be used to distinguish between confined and unconfined turbidites? Results suggest that: i) best practices of data collection are crucial to a meaningful interpretation of sample data statistics, especially in presence of stratigraphic and spatial trends of turbidite bed thickness; ii) a systematic bias against cm-thick Tcd Bouma sequence turbidites exists in sample data, which can result in the low-end tail of empirical thickness-frequency distributions to depart significantly from the actual distribution of turbidite thickness; and iii) thickness statistics of beds starting with a basal Ta/Tb Bouma division bear a coherent relationship to the transition from ponded to unconfined depositional settings, consisting in reduction of variance and mean and, consequently, parameters, or even type, of best fit model distribution. This research highlights the role of flow stripping, sediment by

  20. Thickness filters for gradient based multi-material and thickness optimization of laminated composite structures

    DEFF Research Database (Denmark)

    Sørensen, Rene; Lund, Erik

    2015-01-01

    This paper presents a new gradient based method for performing discrete material and thickness optimization of laminated composite structures. The novelty in the new method lies in the application of so-called casting constraints, or thickness filters in this context, to control the thickness...... variation throughout the laminate. The filters replace the layerwise density variables with a single continuous through-the-thickness design variable. Consequently, the filters eliminate the need for having explicit constraints for preventing intermediate void through the thickness of the laminate....... Therefore, the filters reduce both the number of constraints and design variables in the optimization problem. Based upon a continuous approximation of a unit step function, the thickness filters are capable of projecting discrete 0/1 values to the underlying layerwise or ”physical” density variables which...

  1. Relationship between the thickness of the renal cortex and age: study with CT measurement

    International Nuclear Information System (INIS)

    Xu Yufeng; Tang Guangjian

    2004-01-01

    Objective: To study the relationship between the renal cortical thickness and age, and to establish the range of the normal renal cortex thickness by using CT measurement in different age groups so as to obtain a best age-related and practicable method for clinical measurement. Methods: (1) the accuracy of measuring renal cortical thickness by CT was evaluated: 18 kidney resected due to renal neoplasm were studied and the cortical thickness of the normal part of these specimens was assessed. The difference between the renal cortical thickness of specimens and preoperative measurements of renal cortex of the same patient by contrast enhanced CT was analyzed statistically. (2) 120 patients without history of renal disease or long term usage of potentially renal toxic drugs or history of hypertension were examined by CT with indication (s) other than renal disease. All the patients were divided into 20-40, 41-60, and 61-80 year-old groups. The renal cortical and parenchymal thickness and renal size were measured in three CT sections. The difference of the measurements among the three groups and their relationship to age was analyzed statistically. Results: There was no significant difference between the renal cortical thickness measured by enhanced spiral CT and measured in renal specimens (t=0.80, P=0.43). The renal cortical thickness in three groups was 0.73 cm, 0.65 cm, and 0.53 cm, respectively, and the differences among the three groups were significant (F=93.430, P 0.05). Conclusion: The measurement of the renal cortical thickness with enhanced spiral CT was reliable and was a sensitive method in investigating the morphologic changes of the kidney. The renal cortical thickness of normal kidney diminishes with age, but the change of the ratio of thickness of renal cortex to renal parenchyma with age was not significant

  2. Noncontact optical measurement of lens capsule thickness ex vivo

    Science.gov (United States)

    Ziebarth, Noel M.; Manns, Fabrice; Uhlhorn, Stephen; Parel, Jean-Marie

    2004-07-01

    Purpose: To design a non-contact optical system to measure lens capsule thickness in cadaver eyes. Methods: The optical system uses a 670nm laser beam delivered to a single-mode fiber coupler. The output of the fiber coupler is focused onto the tissue using an aspheric lens (NA=0.68) mounted on a motorized translation stage. Light reflected from the sample is collected by the fiber coupler and sent to a silicon photodiode connected to a power meter. Peaks in the power signal are detected when the focal point of the aspheric lens coincides with the capsule boundaries. The capsule thickness is proportional to the distance between successive peaks. Anterior and posterior lens capsule thickness measurements were performed on 13 human, 10 monkey, and 34 New Zealand white rabbit lenses. The cadaver eyes were prepared for optical measurements by bonding a PMMA ring on the sclera. The posterior pole was sectioned, excess vitreous was removed, and the eye was placed on a Teflon slide. The cornea and iris were then sectioned. After the experiments, the lenses were excised, placed in 10% buffered formalin, and prepared for histology. Results: Central anterior lens capsule thickness was 9.4+/-2.9μm (human), 11.2+/-6.6μm (monkey), and 10.3+/-3.6μm (rabbit) optically and 14.9+/-1.6μm (human), 17.7+/-4.9μm (monkey), and 12.6+/-2.3μm (rabbit) histologically. The values for the central posterior capsule were 9.4+/-2.9μm (human), 6.6+/-2.5μm (monkey), and 7.9+/-2.3μm (rabbit) optically and 4.6+/-1.4μm (human), 4.5+/-1.2μm (monkey), and 5.7+/-1.7μm (rabbit) histologically. Conclusions: This study demonstrates that a non-contact optical system can successfully measure lens capsule thickness in cadaver eyes.

  3. Visceral fat is more important than peripheral fat for endometrial thickness and bone mass in healthy postmenopausal women

    DEFF Research Database (Denmark)

    Warming, Lise; Ravn, Pernille; Christiansen, Claus

    2003-01-01

    OBJECTIVE: The purpose of this study was to investigate the influence of body mass index and body composition on endometrial thickness and bone mass. STUDY DESIGN: This was a cross-sectional study that included 531 healthy postmenopausal women aged 48 to 65 years. Endometrial thickness was measured...

  4. Uncertainty estimation of ultrasonic thickness measurement

    International Nuclear Information System (INIS)

    Yassir Yassen, Abdul Razak Daud; Mohammad Pauzi Ismail; Abdul Aziz Jemain

    2009-01-01

    The most important factor that should be taken into consideration when selecting ultrasonic thickness measurement technique is its reliability. Only when the uncertainty of a measurement results is known, it may be judged if the result is adequate for intended purpose. The objective of this study is to model the ultrasonic thickness measurement function, to identify the most contributing input uncertainty components, and to estimate the uncertainty of the ultrasonic thickness measurement results. We assumed that there are five error sources significantly contribute to the final error, these sources are calibration velocity, transit time, zero offset, measurement repeatability and resolution, by applying the propagation of uncertainty law to the model function, a combined uncertainty of the ultrasonic thickness measurement was obtained. In this study the modeling function of ultrasonic thickness measurement was derived. By using this model the estimation of the uncertainty of the final output result was found to be reliable. It was also found that the most contributing input uncertainty components are calibration velocity, transit time linearity and zero offset. (author)

  5. Thickness dependent properties of magnetic ultrathin films

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Bach Thanh [Faculty of Physics, Hanoi University of Science, VNU, 334 Nguyen Trai, Hanoi (Viet Nam); Thao, Pham Huong, E-mail: hthao82@gmail.com [Faculty of Physics, Hanoi University of Science, VNU, 334 Nguyen Trai, Hanoi (Viet Nam); Faculty of Physics, Hue College of Education, 32 Le Loi, Thua Thien Hue (Viet Nam)

    2013-10-01

    The dependence of magnetic properties on the thickness of few-layer thin films is investigated at finite temperature using the functional integral method for solving the Heisenberg spin model. The temperature dependence of the ultra-thin film's magnetization and Curie temperature are calculated in terms of the mean field theory and of the Gaussian spin fluctuation approximations. It has been shown that both Curie temperature and temperature interval, where the magnetization is non-zero, are strongly reduced with the thickness reduction by using the spin fluctuation approximations in comparison with the mean field results. Curie temperature dependence on the film thickness calculated numerically well agrees with the experimental data for Ni/Cu(1 0 0) and Ni/Cu(1 1 1) ultrathin films.

  6. Effect of subcooling and wall thickness on pool boiling from downward-facing curved surfaces in water

    Energy Technology Data Exchange (ETDEWEB)

    El-Genk, M.S.; Glebov, A.G. [Univ. of New Mexico, Albuquerque, NM (United States)

    1995-09-01

    Quenching experiments were performed to investigate the effects of water subcooling and wall thickness on pool boiling from a downward-facing curved surface. Experiments used three copper sections of the same diameter (50.8 mm) and surface radius (148 mm), but different thickness (12.8, 20 and 30 mm). Local and average pool boiling curves were obtained at saturation and 5 K, 10 K, and 14 K subcooling. Water subcooling increased the maximum heat flux, but decreased the corresponding wall superheat. The minimum film boiling heat flux and the corresponding wall superheat, however, increased with increased subcooling. The maximum and minimum film boiling heat fluxes were independent of wall thickness above 20 mm and Biot Number > 0.8, indicating that boiling curves for the 20 and 30 thick sections were representative of quasi steady-state, but not those for the 12.8 mm thick section. When compared with that for a flat surface section of the same thickness, the data for the 12.8 mm thick section showed significant increases in both the maximum heat flux (from 0.21 to 0.41 MW/m{sup 2}) and the minimum film boiling heat flux (from 2 to 13 kW/m{sup 2}) and about 11.5 K and 60 K increase in the corresponding wall superheats, respectively.

  7. Glue Film Thickness Measurements by Spectral Reflectance

    Energy Technology Data Exchange (ETDEWEB)

    B. R. Marshall

    2010-09-20

    Spectral reflectance was used to determine the thickness of thin glue layers in a study of the effect of the glue on radiance and reflectance measurements of shocked-tin substrates attached to lithium fluoride windows. Measurements based on profilometry of the components were found to be inaccurate due to flatness variations and deformation of the tin substrate under pressure during the gluing process. The accuracy of the spectral reflectance measurements were estimated to be ±0.5 μm, which was sufficient to demonstrate a convincing correlation between glue thickness and shock-generated light.

  8. Glue Film Thickness Measurements by Spectral Reflectance

    International Nuclear Information System (INIS)

    Marshall, B.R.

    2010-01-01

    Spectral reflectance was used to determine the thickness of thin glue layers in a study of the effect of the glue on radiance and reflectance measurements of shocked-tin substrates attached to lithium fluoride windows. Measurements based on profilometry of the components were found to be inaccurate due to flatness variations and deformation of the tin substrate under pressure during the gluing process. The accuracy of the spectral reflectance measurements were estimated to be ±0.5 (micro)m, which was sufficient to demonstrate a convincing correlation between glue thickness and shock-generated light.

  9. Electromagnetic imaging through thick metallic enclosures

    Directory of Open Access Journals (Sweden)

    Brendan J. Darrer

    2015-08-01

    Full Text Available The ability to image through metallic enclosures is an important goal of any scanning technology for security applications. Previous work demonstrated the penetrating power of electromagnetic imaging through thin metallic enclosures, thus validating the technique for security applications such as cargo screening. In this work we study the limits of electromagnetic imaging through metallic enclosures, considering the performance of the imaging for different thicknesses of the enclosure. Our results show, that our system can image a Copper disk, even when enclosed within a 20 mm thick Aluminum box. The potential for imaging through enclosures of other materials, such as Lead, Copper, and Iron, is discussed.

  10. Hot rolling of thick uranium molybdenum alloys

    Science.gov (United States)

    DeMint, Amy L.; Gooch, Jack G.

    2015-11-17

    Disclosed herein are processes for hot rolling billets of uranium that have been alloyed with about ten weight percent molybdenum to produce cold-rollable sheets that are about one hundred mils thick. In certain embodiments, the billets have a thickness of about 7/8 inch or greater. Disclosed processes typically involve a rolling schedule that includes a light rolling pass and at least one medium rolling pass. Processes may also include reheating the rolling stock and using one or more heavy rolling passes, and may include an annealing step.

  11. Visual Ethnography, Thick Description and Cultural Representation

    Directory of Open Access Journals (Sweden)

    Dipesh Kharel

    2015-12-01

    Full Text Available The purposes of this paper are threefold: to cover historical, theoretical and methodological overview of visual ethnography (photography and film as a research tool in studying culture; to examine visual ethnography as a means of cultural representation, and to discuss visual ethnographic method with Clifford Geertz’s idea of “thick description”. I hope to bring some clarity and consensus to our understanding how visual ethnography can be an adequate research tool for “thick description” and a study of culture. Furthermore, in this paper, I begin by seeing visual ethnography in the context to visual anthropology, photography, ethnographic film, and semiotics.

  12. Terahertz Mapping of Microstructure and Thickness Variations

    Science.gov (United States)

    Roth, Donald J.; Seebo, Jeffrey P.; Winfree, William P.

    2010-01-01

    A noncontact method has been devised for mapping or imaging spatial variations in the thickness and microstructure of a layer of a dielectric material. The method involves (1) placement of the dielectric material on a metal substrate, (2) through-the-thickness pulse-echo measurements by use of electromagnetic waves in the terahertz frequency range with a raster scan in a plane parallel to the substrate surface that do not require coupling of any kind, and (3) appropriate processing of the digitized measurement data.

  13. MULTIPLE THICKNESS TIMES DENSITY GAMMA GAGE

    Science.gov (United States)

    Cherry, N.H.

    1962-07-24

    A device was developed for measuring simultaneously the thicknesses of two dissimilar materials superimposed on each other, such as coating of one material on another. The apparatus utilizes a double gamma radiation source producing radiation in two narrow band energy levels. The different materials attenuate the two bands of energy unequally with the result that a composite signal is received which can be analyzed to separate out the components due to the differing materials and indicate the thickness or densities of the two layers. (AEC)

  14. Decreased Callosal Thickness in Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Luders, Eileen; Narr, Katherine L.; Hamilton, Liberty S.; Phillips, Owen R.; Thompson, Paul M.; Valle, Jessica S.; Del'Homme, Melissa; Strickland, Tony; McCracken, James T.; Toga, Arthur W.; Levitt, Jennifer G.

    2009-01-01

    Background Neuroimaging studies of attention-deficit/hyperactivity disorder (ADHD) have revealed structural abnormalities in the brains of affected individuals. One of the most replicated alterations is a significantly smaller corpus callosum (CC), for which conflicting reports exist with respect to the affected callosal segments. Methods We applied novel surface-based geometrical modeling methods to establish the presence, direction, and exact location of callosal alterations in ADHD at high spatial resolution. For this purpose, we calculated the thickness of the CC at 100 equidistant midsagittal points in an age-matched male sample of 19 individuals with ADHD and 19 typically developing control subjects. Results In close agreement with many prior observations, the CC was shown to be significantly thinner in ADHD subjects in anterior and, particularly, posterior callosal sections. Covarying for intelligence did not significantly alter the observed ADHD effects. However, group differences were no longer present in anterior sections when covarying for brain volume and after excluding ADHD subjects comorbid for oppositional defiant disorder. Conclusions Decreased callosal thickness may be associated with fewer fibers or a decrease in the myelination of fibers connecting the parietal and prefrontal cortices. This might affect interhemispheric communication channels that are necessary to sustain attention or motor control, thus contributing to symptoms of hyperactivity and impulsivity, or inattention, observed in ADHD. Future studies are necessary to determine whether callosal abnormalities reflect maturational delays or persist into adulthood. PMID:18842255

  15. Friction Stir Welding of Tapered Thickness Welds Using an Adjustable Pin Tool

    Science.gov (United States)

    Adams, Glynn; Venable, Richard; Lawless, Kirby

    2003-01-01

    Friction stir welding (FSW) can be used for joining weld lands that vary in thickness along the length of the weld. An adjustable pin tool mechanism can be used to accomplish this in a single-pass, full-penetration weld by providing for precise changes in the pin length relative to the shoulder face during the weld process. The difficulty with this approach is in accurately adjusting the pin length to provide a consistent penetration ligament throughout the weld. The weld technique, control system, and instrumentation must account for mechanical and thermal compliances of the tooling system to conduct tapered welds successfully. In this study, a combination of static and in-situ measurements, as well as active control, is used to locate the pin accurately and maintain the desired penetration ligament. Frictional forces at the pin/shoulder interface were a source of error that affected accurate pin position. A traditional FSW pin tool design that requires a lead angle was used to join butt weld configurations that included both constant thickness and tapered sections. The pitch axis of the tooling was fixed throughout the weld; therefore, the effective lead angle in the tapered sections was restricted to within the tolerances allowed by the pin tool design. The sensitivity of the FSW process to factors such as thickness offset, joint gap, centerline offset, and taper transition offset were also studied. The joint gap and the thickness offset demonstrated the most adverse affects on the weld quality. Two separate tooling configurations were used to conduct tapered thickness welds successfully. The weld configurations included sections in which the thickness decreased along the weld, as well as sections in which the thickness increased along the weld. The data presented here include weld metallography, strength data, and process load data.

  16. Scattering and absorption differential cross sections for double ...

    Indian Academy of Sciences (India)

    absorption differential cross sections agree with theory within experimental estimated error. Keywords. ... have been given in a previous paper [2] to which we refer for literature on the theoretical studies on this process ... thick iron and 1 mm thick aluminium, with iron facing lead to absorb K x-rays emitted by lead shielding.

  17. Effect of shading technique and thickness on color stability and translucency of new generation translucent zirconia.

    Science.gov (United States)

    Alp, Gülce; Subaşı, Meryem Gülce; Seghi, Robert R; Johnston, William M; Yilmaz, Burak

    2018-03-27

    To evaluate the effect of shading technique and thickness on the color stability and translucency of translucent zirconia after coffee thermocycling. Specimens in different thicknesses (1; 1.5; 2 mm) (n = 4 for each thickness) were sectioned from translucent preshaded zirconia (Pre) and externally shaded zirconia (Ext). After sintering, specimens were glazed and subjected to 10,000 thermocycling in coffee solution. The color coordinates of specimens were measured with a spectroradiometer before and after coffee thermocyling. Color differences and relative translucency parameter (RTP) values were calculated with CIEDE2000 color difference and TP CIEDE2000 formulas. ANOVA was used to analyze the CIEDE2000 color difference and RTP values (α = 0.05). According to 2-way ANOVA, no significant effect of shading technique and thickness on the color difference values was found (P > .05). According to 3-way ANOVA, a significant interaction between the shading technique and thickness (P < .0001) was found for RTP. The RTP parameter decreased with the increase in the thickness. Ext specimens presented significantly higher RTP than Pre specimens (P < .0001), except for between Ext 1 mm and Pre 1 mm (P = .179). Neither shading technique nor tested thicknesses affected the color of translucent zirconia. Shading technique and thickness affected the RTP of translucent zirconia. The RTP was inversely affected with the thickness of the material. Externally shaded zirconia presented higher RTP than preshaded zirconia for specimens thicker than 1 mm. Discoloration with coffee was insignificant for the tested translucent zirconia in tested thicknesses (1, 1.5, 2 mm). When a translucent restoration is intended, thinner externally shaded translucent zirconia restorations should be preferred instead of preshaded translucent zirconia. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Fatigue behavior of thick composite single lap joints

    Energy Technology Data Exchange (ETDEWEB)

    Tang, J.H.; Sridhar, I.; Srikanth, N. [Nanyang Technological Univ., Singapore (Singapore)

    2012-07-01

    In consideration of bondline thickness variability, in bonded joints where thick adherend is adopted, relative thick adhesive layer (2-5 mm) is preferable. This paper aims to give some insight in fatigue strength of adhesively bonded structures involving thick adherend coupled with thick adhesive layer. Single lap joints with nominal adherend thickness of 8 mm and two different nominal thicknesses (2.5 mm and 5.5 mm) were made and tested under fatigue loading. The failure mode exhibits always a tendency for interfacial initiation, followed by interlaminar separation. Fatigue strength for higher adhesive thickness is found to be lower. (Author)

  19. Improved nucleonic coal-thickness monitor

    Science.gov (United States)

    Crouch, C. E.; Rose, S. D.; Jones, E. W.

    1979-01-01

    Design for coal-thickness-sensing instrument features independent hydropneumatic suspension of radiation source and detector. Monitor uses source and detector which are independently mounted, to follow contour of coal surface more closely and to eliminate errors caused by variations in airgap along radiation path. Device may help to bring fully-automated coal mining closer to reality.

  20. Determination of the Optimum Thickness of Approximately ...

    African Journals Online (AJOL)

    In an attempt to conserve the world's scarce energy and material resources, a balance between the cost of heating a material and the optimum thickness of the material becomes vey essential. One of such materials is the local cast aluminium pot commonly used as cooking ware in Nigeria. This paper therefore sets up a ...

  1. Factors Influencing Endometrial Thickness in Postmenopausal Women

    African Journals Online (AJOL)

    Background: Cut‑off values for endometrial thickness (ET) in asymptomatic postmenopausal woman have been standardized. However, there are no comprehensive studies to document how various factors can influence the ET after the age of menopause. Aim: To study the various factors influencing the ET in ...

  2. Vibration of Elastic Functionally Graded Thick Rings

    Directory of Open Access Journals (Sweden)

    Guang-Hui Xu

    2017-01-01

    Full Text Available The free vibration behaviors of functionally graded rings were investigated theoretically. The material graded in the thickness direction according to the power law rule and the rings were assumed to be in plane stress and plane strain states. Based on the first-order shear deformation theory and the kinetic relation of von Kárman type, the frequency equation for free vibration of functionally graded ring was derived. The derived results were verified by those in literatures which reveals that the present theory can be appropriate to predict the free vibration characteristics for quite thick rings with the radius-to-thickness ratio from 60 down to 2.09. Comparison between the plane stress case and the plane strain case indicates a slight difference. Meanwhile, the effects of the structural dimensional parameters and the material inhomogeneous parameter are examined. It is interesting that the value of the logarithmic form of vibration frequency is inversely proportional to the logarithmic form of the radius-to-thickness ratio or the mean radius.

  3. Percolation effect in thick film superconductors

    International Nuclear Information System (INIS)

    Sali, R.; Harsanyi, G.

    1994-01-01

    A thick film superconductor paste has been developed to study the properties of granulated superconductor materials, to observe the percolation effect and to confirm the theory of the conducting mechanism in the superconducting thick films. This paste was also applied to make a superconducting planar transformer. Due to high T c and advantageous current density properties the base of the paste was chosen to be of Bi(Pb)SrCaCuO system. For contacts a conventional Ag/Pt paste was used. The critical temperature of the samples were between 110 K and 115 K depending on the printed layer thickness. The critical current density at the boiling temperature of the liquid He- was between 200-300 A/cm 2 . The R(T) and V(I) functions were measured with different parameters. The results of the measurements have confirmed the theory of conducting mechanism in the material. The percolation structure model has been built and described. As an application, a superconducting planar thick film transformer was planned and produced. Ten windings of the transformer were printed on one side of the alumina substrate and one winding was printed on the other side. The coupling between the two sides was possible through the substrate. The samples did not need special drying and firing parameters. After the preparation, the properties of the transformer were measured. The efficiency and the losses were determined. Finally, some fundamental advantages and problems of the process were discussed

  4. Extensive calvarial exposure and full thickness sequestration ...

    African Journals Online (AJOL)

    Background: Calvarial osteomyelitis is an uncommon complication of burn injury due to electricity. Patient: A case of electrical injury that progressed from full thickness scalp loss to calvarial osteomyelitis and sequestration of outer and inner tables seen after one year of calvarial exposure is presented. Result: The patient ...

  5. Relationship between Central Corneal Thickness, Vitreous ...

    African Journals Online (AJOL)

    The central corneal thickness (CCT), Vitreous chamber depth (VCD) and axial length (AL) are important ocular parameters used in the assessment of ocular health in relation to some ocular morbidities. Determining the differences in these parameters in relation to each other is fundamental to understanding the general eye ...

  6. Thick beryllium coatings by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H; Nikroo, A; Youngblood, K; Moreno, K; Wu, D; Fuller, T; Alford, C; Hayes, J; Detor, A; Wong, M; Hamza, A; van Buuren, T; Chason, E

    2011-04-14

    Thick (>150 {micro}m) beryllium coatings are studied as an ablator material of interest for fusion fuel capsules for the National Ignition Facility (NIF). As an added complication, the coatings are deposited on mm-scale spherical substrates, as opposed to flats. DC magnetron sputtering is used because of the relative controllability of the processing temperature and energy of the deposits. We used ultra small angle x-ray spectroscopy (USAXS) to characterize the void fraction and distribution along the spherical surface. We investigated the void structure using a combination focused ion beam (FIB) and scanning electron microscope (SEM), along with transmission electron microscopy (TEM). Our results show a few volume percent of voids and a typical void diameter of less than two hundred nanometers. Understanding how the stresses in the deposited material develop with thickness is important so that we can minimize film cracking and delamination. To that end, an in-situ multiple optical beam stress sensor (MOSS) was used to measure the stress behavior of thick Beryllium coatings on flat substrates as the material was being deposited. We will show how the film stress saturates with thickness and changes with pressure.

  7. DNA Translocation in Nanometer Thick Silicon Nanopores.

    Science.gov (United States)

    Rodríguez-Manzo, Julio A; Puster, Matthew; Nicolaï, Adrien; Meunier, Vincent; Drndić, Marija

    2015-06-23

    Solid-state nanopores are single-molecule sensors that detect changes in ionic conductance (ΔG) when individual molecules pass through them. Producing high signal-to-noise ratio for the measurement of molecular structure in applications such as DNA sequencing requires low noise and large ΔG. The latter is achieved by reducing the nanopore diameter and membrane thickness. While the minimum diameter is limited by the molecule size, the membrane thickness is constrained by material properties. We use molecular dynamics simulations to determine the theoretical thickness limit of amorphous Si membranes to be ∼1 nm, and we designed an electron-irradiation-based thinning method to reach that limit and drill nanopores in the thinned regions. Double-stranded DNA translocations through these nanopores (down to 1.4 nm in thickness and 2.5 nm in diameter) provide the intrinsic ionic conductance detection limit in Si-based nanopores. In this regime, where the access resistance is comparable to the nanopore resistance, we observe the appearance of two conductance levels during molecule translocation. Considering the overall performance of Si-based nanopores, our work highlights their potential as a leading material for sequencing applications.

  8. Thickness dependence of nanofilm elastic modulus

    Czech Academy of Sciences Publication Activity Database

    Fedorchenko, Alexander I.; Wang, A. B.; Cheng, H.H.

    2009-01-01

    Roč. 94, č. 15 (2009), s. 152111-152113 ISSN 0003-6951 Institutional research plan: CEZ:AV0Z20760514 Keywords : nanofilm * elastic modulus * thickness dependence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.554, year: 2009 http://link.aip.org/link/?APPLAB/94/152111/1

  9. The Relationship between Central Corneal Thickness and ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the relationship between central corneal thickness (CCT) and intraocular pressure (IOP) in a predominantly black population. A total of eighty-five subjects (right eyes) with mean age 44.7 ± 15.1 years consisting of 49 males and 36 females were recruited for this study. The central ...

  10. Mechanical properties of additively manufactured thick honeycombs

    NARCIS (Netherlands)

    Hedayati, R.; Sadighi, M.; Mohammadi-Aghdam, M; Zadpoor, A.A.

    2016-01-01

    Honeycombs resemble the structure of a number of natural and biological materials such as cancellous bone, wood, and cork. Thick honeycomb could be also used for energy absorption applications. Moreover, studying the mechanical behavior of honeycombs under in-plane loading could help understanding

  11. Crustal thickness controlled by plate tectonics

    DEFF Research Database (Denmark)

    Artemieva, Irina M.; Meissner, Rolf

    2012-01-01

    /gabbro–eclogite phase transition in crustal evolution and the links between lithosphere recycling, mafic magmatism, and crustal underplating. We advocate that plate tectonics processes, togetherwith basalt/gabbro–eclogite transition, limit crustal thickness worldwide by providing effective mechanisms of crustal...

  12. Thick tellurium target preparation by vacuum deposition

    CERN Document Server

    Stolarz, A

    1999-01-01

    Tellurium targets of thickness up to 6.5 mg/cm sup 2 on carbon backings were prepared by vacuum deposition. The influence of the crucible dimension, treatment of the backing foil by glow discharge and substrate cooling on the Te sticking efficiency was studied in order to achieve the best yield.

  13. Pathophysiology of Increased Fetal Nuchal Translucency Thickness

    Directory of Open Access Journals (Sweden)

    Chih-Ping Chen

    2010-06-01

    Full Text Available Increased fetal nuchal translucency thickness is associated with trisomy 13, trisomy 18, trisomy 21, Turner syndrome, other sex chromosome abnormalities, as well as many fetal anomalies and genetic syndromes. This article provides a comprehensive review of the cardinal proposed pathophysiology including altered composition of the extracellular matrix, abnormalities of the heart and great arteries, and disturbed or delayed lymphatic development.

  14. Thick tool steel coatings with laser cladding

    NARCIS (Netherlands)

    Ocelik, V.; de Oliveira, U.; De Hosson, J. Th. M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2007-01-01

    This paper concentrates on thick and crack-free laser clad coatings (up to 3 mm). The coating material is a chromium-molybdenum-tungsten-vanadium alloyed high-speed steel that shows high wear resistance, high compressive strength, good toughness, very good dimensional stability on heat treatment and

  15. An evaluation of dental radiograph accuracy in the measurement of enamel thickness.

    Science.gov (United States)

    Grine, F E; Stevens, N J; Jungers, W L

    2001-12-01

    Many studies have employed lateral radiographs to measure the thickness of tooth enamel in recent human and fossil hominid samples, but the accuracy of measurements obtained by this technique has not been assessed. In this study, 20 isolated human maxillary permanent molars were radiographed using the parallel film technique. The crowns were then sectioned longitudinally through the tips of the buccal cusps. Measurements of enamel cap area, and of linear enamel thickness in the occlusal basin and over the metacone apex, were made from the radiographs and corresponding sectioned surfaces. Comparisons of the two sets of values revealed that radiographs generally overestimated enamel thickness but there was considerable variability in the error by which measurements from radiographs either under- or overestimated the true value. Lateral radiographs may provide a rough visual impression of whether a tooth has thin or thick enamel but they do not generally provide for accurate measurement of enamel thickness. Quantitative data on enamel thickness from studies that have employed lateral radiographs should be viewed with circumspection.

  16. ON THE FORMATION OF GALACTIC THICK DISKS

    Energy Technology Data Exchange (ETDEWEB)

    Minchev, I.; Streich, D.; Scannapieco, C.; De Jong, R. S.; Steinmetz, M. [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Martig, M. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)

    2015-05-01

    Recent spectroscopic observations in the Milky Way suggest that the chemically defined thick disk (stars that have high [α/Fe] ratios and are thus old) has a significantly smaller scale-length than the thin disk. This is in apparent contradiction with observations of external edge-on galaxies, where the thin and thick components have comparable scale-lengths. Moreover, while observed disks do not flare (scale-height does not increase with radius), numerical simulations suggest that disk flaring is unavoidable, resulting from both environmental effects and secular evolution. Here we address these problems by studying two different suites of simulated galactic disks formed in the cosmological context. We show that the scale-heights of coeval populations always increase with radius. However, the total population can be decomposed morphologically into thin and thick disks, which do not flare. We relate this to the disk inside-out formation, where younger populations have increasingly larger scale-lengths and flare at progressively larger radii. In this new picture, thick disks are composed of the imbedded flares of mono-age stellar populations. Assuming that disks form inside out, we predict that morphologically defined thick disks must show a decrease in age (or [α/Fe] ratios) with radius and that coeval populations should always flare. This also explains the observed inversion in the metallicity and [α/Fe] gradients for stars away from the disk midplane in the Milky Way. The results of this work are directly linked to, and can be seen as evidence of, inside-out disk growth.

  17. Relationship between Echocardiographic Epicardial Adipose Tissue (EAT) Thickness and Angiographically Detected Coronary Artery Disease.

    Science.gov (United States)

    Bhuiyan, G R; Roy, G C; Siddique, M A; Rahman, M; Ahmed, K; Nahar, F

    2017-07-01

    Epicardial adipose tissue (EAT) is a particular form of visceral adipose tissue deposited around the heart and there is growing evidence about the physiological and metabolic importance of EAT, especially in the association of cardiovascular risk profiles and the pathogenesis of atherosclerotic coronary artery disease. This observational, cross sectional study was done to determine the relationship between echocardiographic epicardial adipose tissue (EAT) thickness and coronary artery disease (CAD). Total 123 patients with established or suspected coronary artery disease admitted for coronary angiogram in the department of Cardiology of Bangabandhu Sheikh Mujib Medical University (BSMMU) from November 2010 to the end of April 2011 were included in this study. Epicardial adipose tissue (EAT) thickness measurements by echocardiography were compared with coronary angiographic findings. Echocardiographic epicardial adipose tissue (EAT) thickness was significantly higher in patients with CAD in comparison to those with normal coronary arteries (6.67±2.24mm vs. 4.61±1.62mm; pEAT thickness increased with the severity of CAD (multi-vessel disease 7.99±2.12mm vs. single vessel disease 5.93±1.97mm; pEAT thickness (r=0.617, pEAT) thickness as a predictor of angiographic CAD was 6.44mm with 45.31% sensitivity and 92.86% specificity [ROC area 0.756, pEAT) thickness was significantly correlated with the presence and severity of angiographically detected coronary artery disease (CAD).

  18. Measurement of abdominal muscle thickness using M-mode ultrasound imaging during functional activities.

    Science.gov (United States)

    Bunce, Steve M; Hough, Alan D; Moore, Ann P

    2004-02-01

    Ultrasound imaging has been previously utilized in the measurement of muscle thickness and cross-sectional area in research studies, and advocated as a clinical biofeedback tool in the rehabilitation of transversus abdominis function following episodes of low back pain. This paper describes how the thickness of the abdominal muscles can be quantified with a new measurement technique using M-mode ultrasound. The technique uses a custom-made transducer holder that facilitates measurement of muscle thickness changes during functional activity. Limitations of the technique and potential future applications are discussed. The M-mode ultrasound technique may provide an effective method for the non-invasive measurement of abdominal muscle thickness during functional activities.

  19. Vacuum Chambers for LEP sections

    CERN Multimedia

    1983-01-01

    The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

  20. Thickness evaluation using a new relationship between film density and penetrated thickness in radiography

    International Nuclear Information System (INIS)

    Lee, Sung Sik; Kim, Young H.

    2005-01-01

    In order to improve the accuracies in the thickness evaluation using radiography, a new relationship between film density and penetrated thickness has been proposed, and experimental verification of the proposed relationship was carried out by using the X- and γ-ray radiographs of two carbon steel step wedges. A new parameter, the logarithmic gradient of film density, was defined in order to express the characteristics of the radiographic film for wider range of film density. A new relationship between the film density and the penetrated thickness were formulated using the logarithmic gradient of the film density. In experiment, the logarithmic gradient of the film density was independent on both the exposure and the film density and measured for the radiographic film used in the present work from the slope of the fitting lines for the same penetrated thickness. Experimental results verifies the accuracy of the proposed relationship between film density and the penetrated thickness for the range of film density from 1.0 to 3.5. The thickness can be more accurately determined by using the proposed relationship and the parameters determined by experiment. It is also found that the γ-ray having simple energy spectrum is more appropriate radiation source for the evaluation of the thickness from the film density of the radiograph

  1. Mandibular thickness measurements in young dentate adults.

    Science.gov (United States)

    Beaty, Narlin B; Le, Thomas T

    2009-09-01

    To measure thicknesses in clinical landmark areas of the dentate mandibles of young men and women. Using standard radiologic software, we obtained mean (SD) thickness measurements at the inferior or posterior borders of the mandible at the following 7 surgically useful sites: (1) the symphysis, (2) a point halfway between the symphysis and the mental nerve, (3) the mental nerve, (4) a point halfway between the mental nerve and the facial artery notch, (5) the facial artery notch, (6) the angle vertex, and (7) the ramus-condylar neck border. University hospital. A total of 150 dentate men and 75 dentate women aged 18 to 30 years who had undergone computed tomography of the head and neck region during the period of December 20, 2006 to February 20, 2007. Thicknesses of 7 mandibular sites. Mean (SD) thicknesses at the 7 mandibular sites were as follows: symphysis, 14.03 (1.53) mm for men and 13.21 (1.46) mm for women; halfway between the symphysis and the mental nerve, 11.17 (1.37) mm for men and 10.00 (1.08) mm for women; mental nerve, 9.48 (1.28) mm for men and 8.72 (1.00) mm for women; halfway between the mental nerve and the facial artery notch, 10.33 (1.24) mm for men and 9.45 (0.92) mm for women; facial artery notch, 7.27 (0.82) mm for men and 7.10 (0.88) mm for women; angle vertex, 5.42 (0.90) mm for men and 5.39 (0.66) mm for women; and ramus-condylar neck border, 5.90 (0.86) mm for men and 5.85 (0.71) mm for women. Clinical landmark areas in young dentate mandibles have mean thicknesses with limited SDs. The thickness measurements obtained at the sites in this study provide practical reference information for mandibular reconstruction and bicortical screw length estimation.

  2. Predicting gravity and sediment thickness in Afghanistan

    Science.gov (United States)

    Jung, W.; Brozena, J.; Peters, M.

    2013-02-01

    The US Naval Research Laboratory conducted comprehensive high-altitude (7 km above mean sea level) aero-geophysical surveys over Afghanistan in 2006 (Rampant Lion I). The surveys were done in collaboration with the US Geological Survey and upon the request of Islamic Republic of Afghanistan Ministry of Mines. In this study, we show that a best fitting admittance between topography and airborne gravity in western Afghanistan can be used to predict airborne gravity for the no-data area of eastern Afghanistan where the mountains are too high to conduct airborne surveys, due to the threat of ground fire. The differences between the airborne and the predicted gravity along a tie-track through the no-data area were found to be within ±12 mGal range with rms difference 7.3 mGal, while those between the predicted gravity from a simple Airy model (with compensation depth of 32 km and crustal density of 2.67 g cm-3) and the airborne gravity were within ±22 mGal range with rms difference 10.3 mGal. A combined airborne free-air anomaly has been constructed by merging the predicted gravity with the airborne data. We also demonstrate that sediment thickness can be estimated for basin areas where surface topography and airborne free-air anomaly profiles do not show a correlation presumably because of thick sediments. In order to estimate sediment thickness, we first determine a simple linear relationship from a scatter plot of the airborne gravity points and the interpolated Shuttle Radar Topography Mission (SRTM) topography along the Rampant Lion I tracks, and computed corresponding quasi-topography tracks by multiplying the linear relationship with the airborne free-air anomalies. We then take the differences between the SRTM and quasi-topography as a first-order estimate of sediment thickness. A global gravity model (GOCO02S), upward continued to the same altitude (7 km above mean sea level) as the data collection, was compared with the low-pass filtered (with cutoff

  3. The heterogeneous ice shell thickness of Enceladus

    Science.gov (United States)

    Lucchetti, Alice; Pozzobon, Riccardo; Mazzarini, Francesco; Cremonese, Gabriele; Massironi, Matteo

    2016-10-01

    Saturn's moon Enceladus is the smallest Solar System body that presents an intense geologic activity on its surface. Plumes erupting from Enceladus' South Polar terrain (SPT) provide direct evidence of a reservoir of liquid below the surface. Previous analysis of gravity data determined that the ice shell above the liquid ocean must be 30-40 km thick from the South Pole up to 50° S latitude (Iess et al., 2014), however, understand the global or regional nature of the ocean beneath the ice crust is still challenging. To infer the thickness of the outer ice shell and prove the global extent of the ocean, we used the self-similar clustering method (Bonnet et al., 2001; Bour et al., 2002) to analyze the widespread fractures of the Enceladus's surface. The spatial distribution of fractures has been analyzed in terms of their self-similar clustering and a two-point correlation method was used to measure the fractal dimension of the fractures population (Mazzarini, 2004, 2010). A self-similar clustering of fractures is characterized by a correlation coefficient with a size range defined by a lower and upper cut-off, that represent a mechanical discontinuity and the thickness of the fractured icy crust, thus connected to the liquid reservoir. Hence, this method allowed us to estimate the icy shell thickness values in different regions of Enceladus from SPT up to northern regions.We mapped fractures in ESRI ArcGis environment in different regions of the satellite improving the recently published geological map (Crow-Willard and Pappalardo, 2015). On these regions we have taken into account the fractures, such as wide troughs and narrow troughs, located in well-defined geological units. Firstly, we analyzed the distribution of South Polar Region fracture patterns finding an ice shell thickness of ~ 31 km, in agreement with gravity measurements (Iess et al., 2014). Then, we applied the same approach to other four regions of the satellite inferring an increasing of the ice

  4. Thin section casting program. Volume 2: Horizontal TSC (Thin-Section Casting) approach

    Science.gov (United States)

    1989-01-01

    In horizontal thin-section casting (HTSC), 1-inch-thick steel sections are produced at speeds up to 600 ipm or about 60 tons per hour per foot of width (tphf). Liquid steel is fed from the ladle, and flows through a specially designed tundish, then flows through a refractory feeding tube and nozzle, with approximately the same external dimensions as the cast section, into a near-horizontal rectangular mold whose all four sides are traveling in the same direction and speed as the steel casting. This report is the second of a six volume set on thin section casting. This volume covers the research on horizontal thin section casting (TSC).

  5. Correlates of eggshell thickness | Okereke | Global Journal of Pure ...

    African Journals Online (AJOL)

    This study discussed the effects of age and genotype of birds and location of farm on eggshell thickness. The ultimate objective of the study is to determine the correlates of eggshell thickness which may be relevant to improve eggshell thickness. Secondary data on eggshell thickness collected from the Agricultural ...

  6. Compressive strength of thick composite panels

    DEFF Research Database (Denmark)

    Branner, Kim; Berring, Peter

    2011-01-01

    The aim of this study is to investigate how much the compressive strength of thick composite panels is reduced due to delaminations and to investigate under which conditions a delamination will grow. Understanding of this is essential in order to move forward the design limits used in the structu......The aim of this study is to investigate how much the compressive strength of thick composite panels is reduced due to delaminations and to investigate under which conditions a delamination will grow. Understanding of this is essential in order to move forward the design limits used...... in the structural design process. Results obtained from finite element modeling analyses are compared with an experimental test campaign performed on flat composite panels with and without delaminations....

  7. Properties of conductive thick-film inks

    Science.gov (United States)

    Holtze, R. F.

    1972-01-01

    Ten different conductive inks used in the fabrication of thick-film circuits were evaluated for their physical and handling properties. Viscosity, solid contents, and spectrographic analysis of the unfired inks were determined. Inks were screened on ceramic substrates and fired for varying times at specified temperatures. Selected substrates were given additional firings to simulate the heat exposure received if thick-film resistors were to be added to the same substrate. Data are presented covering the (1) printing characteristics, (2) solderability using Sn-63 and also a 4 percent silver solder, (3) leach resistance, (4) solder adhesion, and (5) wire bonding properties. Results obtained using different firing schedules were compared. A comparison was made between the various inks showing general results obtained for each ink. The changes in firing time or the application of a simulated resistor firing had little effect on the properties of most inks.

  8. Metallic oxide switches using thick film technology

    Science.gov (United States)

    Patel, D. N.; Williams, L., Jr.

    1974-01-01

    Metallic oxide thick film switches were processed on alumina substrates using thick film technology. Vanadium pentoxide in powder form was mixed with other oxides e.g., barium, strontium copper and glass frit, ground to a fine powder. Pastes and screen printable inks were made using commercial conductive vehicles and appropriate thinners. Some switching devices were processed by conventional screen printing and firing of the inks and commercial cermet conductor terminals on 96% alumina substrates while others were made by applying small beads or dots of the pastes between platinum wires. Static, and dynamic volt-ampere, and pulse tests indicate that the switching and self-oscillatory characteristics of these devices could make them useful in memory element, oscillator, and automatic control applications.

  9. Buckling Response of Thick Functionally Graded Plates

    Directory of Open Access Journals (Sweden)

    BOUAZZA MOKHTAR

    2014-11-01

    Full Text Available In this paper, the buckling of a functionally graded plate is studied by using first order shear deformation theory (FSDT. The material properties of the plate are assumed to be graded continuously in the direction of thickness. The variation of the material properties follows a simple power-law distribution in terms of the volume fractions of constituents. The von Karman strains are used to construct the equilibrium equations of the plates subjected to two types of thermal loading, linear temperature rise and gradient through the thickness are considered. The governing equations are reduced to linear differential equation with boundary conditions yielding a simple solution procedure. In addition, the effects of temperature field, volume fraction distributions, and system geometric parameters are investigated. The results are compared with the results of the no shear deformation theory (classic plate theory, CPT.

  10. Hybrid Optimization for Wind Turbine Thick Airfoils

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, F. [ECN Wind Energy, Petten (Netherlands)

    2012-06-15

    One important element in aerodynamic design of wind turbines is the use of specially tailored airfoils to increase the ratio of energy capture and reduce cost of energy. This work is focused on the design of thick airfoils for wind turbines by using numerical optimization. A hybrid scheme is proposed in which genetic and gradient based algorithms are combined together to improve the accuracy and the reliability of the design. Firstly, the requirements and the constraints for this class of airfoils are described; then, the hybrid approach is presented. The final part of this work is dedicated to illustrate a numerical example regarding the design of a new thick airfoil. The results are discussed and compared to existing airfoils.

  11. Autonomous Sea-Ice Thickness Survey

    Science.gov (United States)

    2016-06-01

    reflects real variations in ice thickness of about ±0.1 m while the higher-frequency variations probably resulted from movement of the arms of the...E Ray, E. Trautmann, L. A. Barna, and A. M Burzynski. 2013. Autonomous GPR Surveys Using Polar Rover Yeti. Journal of Field Robotics 30 (2): 194...215. Lever, J. H., Z. Courville, and D. Punt. 2016. Robotic Ground-Penetrating-Radar (GPR) Surveys to Support the 2014 Greenland Inland Traverse

  12. Accelerating Thick Aluminum Liners Using Pulsed Power

    International Nuclear Information System (INIS)

    Kyrala, G.A.; Hammerburg, J.E.; Bowers, D.; Stokes, J.; Morgan, D.V.; Anderson, W.E.; Cochrane, J.C.

    1999-01-01

    The authors have investigated the acceleration of very thick cylindrical aluminum liners using the Pegasus II capacitory bank. These accelerated solid liners will be used to impact other objects at velocities below 1.5 km/sec, allowing one to generate and sustain shocks of a few 100 kilobar for a few microseconds. A cylindrical shell of 1100 series aluminum with an initial inner radius of 23.61 mm, an initial thickness of 3.0 mm, and a height of 20 mm, was accelerated using a current pulse of 7.15 MA peak current and a 7.4 microsecond quarter cycle time. The aluminum shell was imploded within confining copper glide planes with decreasing separation with an inward slope of 8 degrees. At impact with a cylindrical target of diameter 3-cm, the liner was moving at 1.4 km/sec and its thickness increased to 4.5 mm. Radial X-ray radiograms of the liner showed both the liner and the glide plane interface. The curvature of the inner surface of the liner was measured before impact with the 15-mm radius target. The radiograms also showed that the copper glide planes distorted as the liner radius decreased and that some axial stress is induced in the liner. The axial stresses did not affect the inner curvature significantly. Post-shot calculations of the liner behavior indicated that the thickness of the glide plane played a significant role in the distortion of the interface between the liner and the glide plane

  13. 3D position readout from thick scintillators

    CERN Document Server

    Antich, P; Parkey, R; Slavin, N V; Tsyganov, E N

    2002-01-01

    A novel technique has been developed and tested for the three-dimensional measurement of position in SPECT-PET detectors. Results are presented for 2 and 20 mm thick NaI(Tl) planar crystals. In a plane of crystal, a coordinate resolution of about 1 mm (rms error) is demonstrated. The depth of interaction (DOI) is measured with an rms error of about 2 mm using light cone parameters.

  14. A de Sitter tachyon thick braneworld

    Energy Technology Data Exchange (ETDEWEB)

    Germán, Gabriel; Herrera-Aguilar, Alfredo; Malagón-Morejón, Dagoberto [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apdo. Postal 48-3, 62251, Cuernavaca, Morelos (Mexico); Mora-Luna, Refugio Rigel [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Ciudad Universitaria, C.P. 58040, Morelia, Michoacán (Mexico); Rocha, Roldão da, E-mail: gabriel@fis.unam.mx, E-mail: aha@fis.unam.mx, E-mail: malagon@ifm.umich.mx, E-mail: rigel@ifm.umich.mx, E-mail: roldao.rocha@ufabc.edu.br [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, Rua Santa Adélia, 166 09210-170, Santo André, SP (Brazil)

    2013-02-01

    Among the multiple 5D thick braneworld models that have been proposed in the last years, in order to address several open problems in modern physics, there is a specific one involving a tachyonic bulk scalar field. Delving into this framework, a thick braneworld with a cosmological background induced on the brane is here investigated. The respective field equations — derived from the model with a warped 5D geometry — are highly non-linear equations, admitting a non-trivial solution for the warp factor and the tachyon scalar field as well, in a de Sitter 4D cosmological background. Moreover, the non-linear tachyonic scalar field, that generates the brane in complicity with warped gravity, has the form of a kink-like configuration. Notwithstanding, the non-linear field equations restricting character does not allow one to easily find thick brane solutions with a decaying warp factor which leads to the localization of 4D gravity and other matter fields. We derive such a thick brane configuration altogether in this tachyon-gravity setup. When analyzing the spectrum of gravity fluctuations in the transverse traceless sector, the 4D gravity is shown to be localized due to the presence of a single zero mode bound state, separated by a continuum of massive Kaluza-Klein (KK) modes by a mass gap. It contrasts with previous results, where there is a KK massive bound excitation providing no clear physical interpretation. The mass gap is determined by the scale of the metric parameter H. Finally, the corrections to Newton's law in this model are computed and shown to decay exponentially. It is in full compliance to corrections reported in previous results (up to a constant factor) within similar braneworlds with induced 4D de Sitter metric, despite the fact that the warp factor and the massive modes have a different form.

  15. Biocompatible wear-resistant thick ceramic coating

    Directory of Open Access Journals (Sweden)

    Vogt Nicola

    2016-09-01

    Full Text Available Sensitisation to immunologically active elements like chromium, cobalt or nickel and debris particle due to wear are serious problems for patients with metallic implants. We tested the approach of using a hard and thick ceramic coating as a wear-resistant protection of titanium implants, avoiding those sensitisation and foreign body problems. We showed that the process parameters strongly influence the coating porosity and, as a consequence, also its hardness.

  16. A quantitative analysis of hip capsular thickness.

    Science.gov (United States)

    Philippon, Marc J; Michalski, Max P; Campbell, Kevin J; Rasmussen, Matthew T; Goldsmith, Mary T; Devitt, Brian M; Wijdicks, Coen A; LaPrade, Robert F

    2015-09-01

    The purpose of this study was to provide a comprehensive quantitative analysis of capsular thickness adjacent to the acetabular rim in clinically relevant locations. Dissections were performed and hip capsular measurements were recorded on 13 non-paired, fresh-frozen cadaveric hemi-pelvises using a coordinate measuring device. Measurements were taken for each clock-face position at 0, 5, 10 and 15 mm distances from the labral edge. The capsule was consistently thickest at 2 o'clock for each interval from the labrum with a maximum thickness of 8.3 at 10 mm [95 % CI 6.8, 9.8] and 15 mm [95 % CI 6.8, 9.7]. The capsule was noticeably thinner between 4 and 11 o'clock with a minimum thickness of 4.1 mm [95 % CI 3.3, 4.9] at 10 o'clock at the labral edge. Direct comparison between 0 and 5 mm between 9 and 3 o'clock showed that the hip capsule was significantly thicker at 5 mm from the labrum at 9 o'clock (p = 0.027), 10 o'clock (p = 0.032), 1 o'clock (p = 0.003), 2 o'clock (p = 0.001) and 3 o'clock (p = 0.001). The hip capsule was thickest between the 1 and 2 o'clock positions for all measured distances from the acetabular labrum and reached its maximum thickness at 2 o'clock, which corresponds to the location of the iliofemoral ligament.

  17. Measurement of the thickness of the bronchial epithelium

    International Nuclear Information System (INIS)

    Bowden, D.H.; Baldwin, F.

    1989-02-01

    Cancer of the lung in uranium miners is thought to be related to the inhalation of gaseous radon daughters which become attached to molecules of water vapour or to dust particles. Since, the depth of tissue penetration by alpha particles is short, the thickness of the epithelium that lines the bronchial tree may be a critical factor in the development of cancers at specific sites in the lung. The objectives of the present study were: 1) to measure the thickness of human bronchial epithelium; 2) to determine the distribution and depth of the nuclei of basal cells in the bronchial epithelium; and 3) to compare these parameters in groups of smokers and non-smokers. Twenty-nine surgically removed specimens of the lung were examined (26 smokers, 3 non-smokers). The specimens were fixed and prepared for examination by light and electron microscopy. Blocks of tissue were oriented so that the maximum number of bronchi were cut in cross-section; measurements included bronchi of all sizes from bronchial generations (1≥ 9.01 mm) diameter to the smallest bronchioles, generations 7 - 16 (0.26 - 2.0 mm). Comparison of measurements in smokers and non-smokers show no significant differences, so that the 29 cases are considered to represent a homogeneous group. With progressive divisions of the bronchi, the epithelium decreases in thickness. Of more importance are the figures relating to the distance from the cell surface to the underlying nucleus. Here too, with the exception of goblet cells, the measurements are significantly smaller in generations 7 - 16 than in generation 1

  18. Adolescent cortical thickness pre- and post marijuana and alcohol initiation.

    Science.gov (United States)

    Jacobus, Joanna; Castro, Norma; Squeglia, Lindsay M; Meloy, M J; Brumback, Ty; Huestis, Marilyn A; Tapert, Susan F

    Cortical thickness abnormalities have been identified in youth using both alcohol and marijuana. However, limited studies have followed individuals pre- and post initiation of alcohol and marijuana use to help identify to what extent discrepancies in structural brain integrity are pre-existing or substance-related. Adolescents (N=69) were followed from ages 13 (pre-initiation of substance use, baseline) to ages 19 (post-initiation, follow-up). Three subgroups were identified, participants that initiated alcohol use (ALC, n=23, >20 alcohol use episodes), those that initiated both alcohol and marijuana use (ALC+MJ, n=23, >50 marijuana use episodes) and individuals that did not initiate either substance regularly by follow-up (CON, n=23, marijuana use episodes). All adolescents underwent neurocognitive testing, neuroimaging, and substance use and mental health interviews. Significant group by time interactions and main effects on cortical thickness estimates were identified for 18 cortical regions spanning the left and right hemisphere (pseffect, in cortical thickness by follow-up for individuals who have not initiated regular substance use or alcohol use only by age 19; modest between-group differences were identified at baseline in several cortical regions (ALC and CON>ALC+MJ). Minimal neurocognitive differences were observed in this sample. Findings suggest pre-existing neural differences prior to marijuana use may contribute to initiation of use and observed neural outcomes. Marijuana use may also interfere with thinning trajectories that contribute to morphological differences in young adulthood that are often observed in cross-sectional studies of heavy marijuana users. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Genetic and Developmental Basis for Increased Leaf Thickness in the Arabidopsis Cvi Ecotype

    Directory of Open Access Journals (Sweden)

    Viktoriya Coneva

    2018-03-01

    Full Text Available Leaf thickness is a quantitative trait that is associated with the ability of plants to occupy dry, high irradiance environments. Despite its importance, leaf thickness has been difficult to measure reproducibly, which has impeded progress in understanding its genetic basis, and the associated anatomical mechanisms that pattern it. Here, we used a custom-built dual confocal profilometer device to measure leaf thickness in the Arabidopsis Ler × Cvi recombinant inbred line population and found statistical support for four quantitative trait loci (QTL associated with this trait. We used publically available data for a suite of traits relating to flowering time and growth responses to light quality and show that three of the four leaf thickness QTL coincide with QTL for at least one of these traits. Using time course photography, we quantified the relative growth rate and the pace of rosette leaf initiation in the Ler and Cvi ecotypes. We found that Cvi rosettes grow slower than Ler, both in terms of the rate of leaf initiation and the overall rate of biomass accumulation. Collectively, these data suggest that leaf thickness is tightly linked with physiological status and may present a tradeoff between the ability to withstand stress and rapid vegetative growth. To understand the anatomical basis of leaf thickness, we compared cross-sections of Cvi and Ler leaves and show that Cvi palisade mesophyll cells elongate anisotropically contributing to leaf thickness. Flow cytometry of whole leaves show that endopolyploidy accompanies thicker leaves in Cvi. Overall, our data suggest that mechanistically, an altered schedule of cellular events affecting endopolyploidy and increasing palisade mesophyll cell length contribute to increase of leaf thickness in Cvi. Ultimately, knowledge of the genetic basis and developmental trajectory leaf thickness will inform the mechanisms by which natural selection acts to produce variation in this adaptive trait.

  20. Factors Affecting the Thickness of Thermal Aureoles

    Directory of Open Access Journals (Sweden)

    Catherine Annen

    2017-10-01

    Full Text Available Intrusions of magma induce thermal aureoles in the country rock. Analytical solutions predict that the thickness of an aureole is proportional to the thickness of the intrusion. However, in the field, thermal aureoles are often significantly thinner or wider than predicted by simple thermal models. Numerical models show that thermal aureoles are wider if the heat transfer in the magma is faster than in the country rock due to contrasts in thermal diffusivities or the effect of magma convection. Large thermal aureoles can also be caused by repeated injection close to the contact. Aureoles are thin when heat transfer in the country rock is faster than heat transfer within the magma or in case of incrementally, slowly emplaced magma. Absorption of latent heat due to metamorphic reactions or water volatilization also affects thermal aureoles but to a lesser extent. The way these parameters affect the thickness of a thermal aureole depends on the isotherm under consideration, hence on which metamorphic phase is used to draw the limit of the aureole. Thermal aureoles provide insight on the dynamics of intrusions emplacement. Although available examples are limited, asymmetric aureoles point to magma emplacement by over-accretion for mafic cases and by under-accretion for felsic cases, consistent with geochronological data.

  1. Decreased central corneal thickness in ankylosing spondylitis.

    Science.gov (United States)

    Ortak, Huseyin; Inanır, Ahmet; Demir, Selim; Uysal, Alper; Şahin, Şafak; Sağcan, Mustafa; Önder, Yalçın; Alim, Sait; Demir, Ayşe Kevser

    2014-04-01

    Central corneal thickness and dry eye tests were evaluated in a study population consisting of 68 ankylosing spondylitis patients diagnosed according to the modified New York criteria, and 61 age-matched controls without ankylosing spondylitis. A full ophthalmological evaluation was performed on each subject. All subjects were screened for age, gender, HLA-B27, tear break-up time test, Schirmer test, and duration of disease. Central corneal thickness was measured under topical anesthesia with an ultrasonic pachymeter. The mean central corneal thickness was 537.3 ± 30.6 μm, range 462-600 μm, in ankylosing spondylitis patients, whereas it was 551.7 ± 25.2 μm, range 510-620 μm, in controls (p = 0.005). The Schirmer test result was 7.3 ± 5.9 mm for the ankylosing spondylitis patients and 11.7 ± 5.8 mm for the control group (p = 0.002). Tear break-up time was 7.3 ± 3.2 s for the ankylosing spondylitis patients and 14.0 ± 4.5 s for the control group (p ankylosing spondylitis. In addition, attention must be given to lower dry eye tests in surgical interventions such as photorefractive keratectomy and laser in situ keratomileusis in ankylosing spondylitis patients.

  2. Decreased cortical thickness in central hypoventilation syndrome.

    Science.gov (United States)

    Macey, Paul M; Moiyadi, Ammar S; Kumar, Rajesh; Woo, Mary A; Harper, Ronald M

    2012-08-01

    Central hypoventilation syndrome (CHS) is a rare condition characterized by hypoventilation during sleep, reduced ventilatory responsiveness to CO(2) and O(2), impaired perception of air hunger, and autonomic abnormalities. Neural impairments accompany the condition, including structural injury, impaired cerebral autoregulation, and dysfunctional autonomic control. The hypoventilation may induce cortical hypoxic injury, additional to consequences of maldevelopment from PHOX2B mutations present in most CHS subjects. We assessed cortical injury in clinically diagnosed CHS using high-resolution magnetic resonance imaging scans, collected from 14 CHS (mean age ± standard deviation [SD] 17.7 ± 5.0 years; 6 female) and 29 control (mean age ± SD, 17.9 ± 4.3 years; 12 female) subjects. We measured group differences in mean cortical thickness and age-thickness correlations using FreeSurfer software, accounting for age and sex (0.1 false discovery rate). Reduced thickness in CHS appeared in the dorsomedial frontal cortex and anterior cingulate; medial prefrontal, parietal, and posterior cingulate cortices; the insular cortex; anterior and lateral temporal lobes; and mid- and accessory motor strips. Normal age-related cortical thinning in multiple regions did not appear in CHS. The cortical thinning may contribute to CHS cardiovascular and memory deficits and may impair affect and perception of breathlessness. Extensive axonal injury in CHS is paralleled by reduced cortical tissue and absence of normal developmental patterns.

  3. Correlation between choroidal thickness and macular hole

    Directory of Open Access Journals (Sweden)

    Li-Li Wang

    2018-01-01

    Full Text Available AIM:To explore the correlation between choroidal thickness and macular hole, and to provide a theoretical basis for diagnosis and treatment of macular hole. METHODS: This study included 40 cases of monocular idiopathic macular hole patients who were treated in ophthalmology of our hospital from June 2015 to June 2016 and 40 cases of healthy people. Sicked eyes of idiopathic macular hole patients(40 eyeswere set as the Group A, uninjured side eyes(40 eyeswere set as the Group B, eyes of 40 cases of healthy people(40 normal eyeswere set as the Group C. Choroidal thickness of macular fovea, macular fovea 1mm, 3mm at 9 points, 4 directions in the upper, lower, nasal and temporal regions were measured through coherent optical tomography of enhanced deep imaging(enhanced depth image optical coherence tomography, EDI-OCT. They were recorded as SFCT, SCT1mm, SCT3mm, ICT1mm, ICT3mm, NCT1mm, NCT3mm, TCT1mm, TCT3mm, and correlation analysis between SFCT and age was analyzed. RESULTS: Average SFCT of Group A, B had no significant difference, data of the Group C was significantly higher than those of the Group A, B, there was statistical significance(P1mm, SCT3mm, ICT1mm, ICT3mm, NCT1mm, NCT3mm, TCT1mm, TCT3mm of the Group A, B had no significant difference(P>0.05, and choroidal thickness at each point of the Group C was significantly higher than that of Group A and B, there was statistical significance(Pr=-0.065, P=0.148; r=-0.057, P=0.658, SFCT of the Group C was negatively correlated with age(r=-0.343, P=0.041. CONCLUSION: The pathogenesis of idiopathic macular hole may be related to the sharp decrease of choroidal thickness, choroidal thickness of uninjured side eyes reduces more sharply than normal population and choroidal vascular metabolism reduces may be pathogenic.

  4. Magnetic susceptibility correlation of km-thick Eifelian–Frasnian sections (Ardennes and Moravia)

    Czech Academy of Sciences Publication Activity Database

    Boulvain, F.; da Silva, A.C.; Mabille, C.; Hladil, Jindřich; Geršl, M.; Koptíková, Leona; Schnabl, Petr

    2010-01-01

    Roč. 13, č. 4 (2010), s. 309-318 ISSN 1374-8505 R&D Projects: GA AV ČR IAA300130702; GA AV ČR IAAX00130702 Institutional research plan: CEZ:AV0Z30130516 Keywords : Devonian limestone * magnetic susceptibility * Moravian Karst * Ardennes Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.645, year: 2010 http://popups.ulg.ac.be/Geol/docannexe.php?id=3181

  5. Correcting the axial shrinkage of skeletal muscle thick sections visualized by confocal microscopy

    Czech Academy of Sciences Publication Activity Database

    Janáček, Jiří; Kreft, M.; Čebašek, V.; Eržen, I.

    2012-01-01

    Roč. 246, č. 2 (2012), s. 107-112 ISSN 0022-2720 R&D Projects: GA MŠk(CZ) MEB090910; GA MŠk(CZ) LC06063 Institutional research plan: CEZ:AV0Z50110509 Keywords : capillaries * confocal microscopy * sample deformation * shrinkage * skeletal muscle * 3D Subject RIV: FH - Neurology Impact factor: 1.633, year: 2012

  6. Friction Stir Welding of Thick Section Aluminum for Military Vehicle Applications

    Science.gov (United States)

    2012-12-01

    range of expected FSW joints. PAUT modeling was performed to develop initial inspection procedures for examining wormhole and lack-of-penetration (LOP...and a wormhole type defect (Figure 8). Figure 8. Lack of Penetration Type Defect (Left) and a Wormhole Type Defect (Right) The first step in

  7. Thick methacrylate sections devoid of lost caps simplify stereological quantifications based on the optical fractionator design

    DEFF Research Database (Denmark)

    Andersen, Stine Hasselholt; Lykkesfeldt, Jens; Larsen, Jytte Overgaard

    2015-01-01

    Abstract In neuroscience, the optical fractionator technique is frequently used for unbiased cell number estimations. Although unbiased in theory, the practical application of the technique is often biased by the necessity of introducing a guard zone at one side of the disector to counter lost caps...

  8. Regional Analysis of Soft Tissue Thickness on Korean Buttocks and Application to Fasciocutaneous Flap Design

    Directory of Open Access Journals (Sweden)

    Do Yup Kim

    2014-03-01

    Full Text Available Background Various shapes and designs of the gluteal artery perforator flap have been used for treating sacral pressure sores and reconstructing breasts. To establish the ideal fasciocutaneous flap design for use in the gluteal area, the soft tissue thickness distribution was measured. Methods Twenty-one buttocks of adult Korean cadavers were analyzed through rectangular subfascial dissection. Each buttock was divided horizontally into 10 sections and vertically into 10 sections, and then, the thickness at the corners of the sections was measured. For the sake of comparison and statistical verification with living bodies, computed tomography (CT images of 120 buttocks of patients were randomly selected. Five horizontal sections and 4 vertical sections were made, and the thickness at each corner was recorded. Results According to the dissection and the CT images, the area with the thinnest soft tissues in the buttock was around the posterior superior iliac spine, close to the sacral area. The thickest area was the superolateral area of the buttock, which was 3.24 times and 2.15 times thicker than the thinnest area in the studies on cadaver anatomy and the CT images, respectively. Conclusions The thickness of the soft tissues in the buttocks differed by area. The superolateral area had the thickest soft tissues, and the superomedial area had the thinnest. This study includes information on the distribution of the thickness of the gluteal soft tissues of Koreans. The outcome of this study may contribute to the design of effective local flaps for pressure sore reconstruction and free flaps for breast reconstruction.

  9. Methods for determining the wall thickness variation of tubular heaters used in thermalhydraulic studies

    International Nuclear Information System (INIS)

    Cubizolles, G.; Garnier, J.; Groeneveld, D.; Tanase, A.

    2009-01-01

    ) Onset of Nucleate Boiling data. The three predicted wall thickness variations were in excellent agreement with each other and also agreed very well with subsequent direct measurements with a precision caliper, and photography-based measurements using slices of the test section. The wall thickness derivation methods used at CEA and UofO are thought to be especially valuable for future thermalhydraulic studies on fuel bundle simulators where heater tubes with a nominal constant wall thickness can have a wall thickness variation of ± 5% and result in a similar variation in surface heat flux. Better knowledge of the wall thickness variation will permit more precise measurements of the local single-phase and boiling heat transfer coefficients. (author)

  10. Comparing electron tomography and HRTEM slicing methods as tools to measure the thickness of nanoparticles

    International Nuclear Information System (INIS)

    Alloyeau, D.; Ricolleau, C.; Oikawa, T.; Langlois, C.; Le Bouar, Y.; Loiseau, A.

    2009-01-01

    Nanoparticles' morphology is a key parameter in the understanding of their thermodynamical, optical, magnetic and catalytic properties. In general, nanoparticles, observed in transmission electron microscopy (TEM), are viewed in projection so that the determination of their thickness (along the projection direction) with respect to their projected lateral size is highly questionable. To date, the widely used methods to measure nanoparticles thickness in a transmission electron microscope are to use cross-section images or focal series in high-resolution transmission electron microscopy imaging (HRTEM 'slicing'). In this paper, we compare the focal series method with the electron tomography method to show that both techniques yield similar particle thickness in a range of size from 1 to 5 nm, but the electron tomography method provides better statistics since more particles can be analyzed at one time. For this purpose, we have compared, on the same samples, the nanoparticles thickness measurements obtained from focal series with the ones determined from cross-section profiles of tomograms (tomogram slicing) perpendicular to the plane of the substrate supporting the nanoparticles. The methodology is finally applied to the comparison of CoPt nanoparticles annealed ex situ at two different temperatures to illustrate the accuracy of the techniques in detecting small particle thickness changes.

  11. Comparing electron tomography and HRTEM slicing methods as tools to measure the thickness of nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Alloyeau, D., E-mail: alloyeau.damien@gmail.com [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); Laboratoire d' Etude des Microstructures - ONERA/CNRS, UMR 104, B.P. 72, 92322 Chatillon (France); Ricolleau, C. [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); Oikawa, T. [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); JEOL (Europe) SAS, Espace Claude Monet, 1 Allee de Giverny, 78290 Croissy-sur-Seine (France); Langlois, C. [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); Le Bouar, Y.; Loiseau, A. [Laboratoire d' Etude des Microstructures - ONERA/CNRS, UMR 104, B.P. 72, 92322 Chatillon (France)

    2009-06-15

    Nanoparticles' morphology is a key parameter in the understanding of their thermodynamical, optical, magnetic and catalytic properties. In general, nanoparticles, observed in transmission electron microscopy (TEM), are viewed in projection so that the determination of their thickness (along the projection direction) with respect to their projected lateral size is highly questionable. To date, the widely used methods to measure nanoparticles thickness in a transmission electron microscope are to use cross-section images or focal series in high-resolution transmission electron microscopy imaging (HRTEM 'slicing'). In this paper, we compare the focal series method with the electron tomography method to show that both techniques yield similar particle thickness in a range of size from 1 to 5 nm, but the electron tomography method provides better statistics since more particles can be analyzed at one time. For this purpose, we have compared, on the same samples, the nanoparticles thickness measurements obtained from focal series with the ones determined from cross-section profiles of tomograms (tomogram slicing) perpendicular to the plane of the substrate supporting the nanoparticles. The methodology is finally applied to the comparison of CoPt nanoparticles annealed ex situ at two different temperatures to illustrate the accuracy of the techniques in detecting small particle thickness changes.

  12. Calculated /alpha/-induced thick target neutron yields and spectra, with comparison to measured data

    International Nuclear Information System (INIS)

    Wilson, W.B.; Bozoian, M.; Perry, R.T.

    1988-01-01

    One component of the neutron source associated with the decay of actinide nuclides in many environments is due to the interaction of decay /alpha/ particles in (/alpha/,n) reactions on low Z nuclides. Measurements of (/alpha/,n) thick target neutron yields and associated neutron spectra have been made for only a few combinations of /alpha/ energy and target nuclide or mixtures of actinide and target nuclides. Calculations of thick target neutron yields and spectra with the SOURCES code require /alpha/-energy-dependent cross sections for (/alpha/,n) reactions, as well as branching fractions leading to the energetically possible levels of the product nuclides. A library of these data has been accumulated for target nuclides of Z /le/ 15 using that available from measurements and from recent GNASH code calculations. SOURCES, assuming neutrons to be emitted isotopically in the center-of-mass system, uses libraries of /alpha/ stopping cross sections, (/alpha/,n) reaction cross reactions, product nuclide level branching fractions, and actinide decay /alpha/ spectra to calculate thick target (/alpha/,n) yields and neutron spectra for homogeneous combinations of nuclides. The code also calculates the thick target yield and angle intergrated neutron spectrum produced by /alpha/-particle beams on targets of homogeneous mixtures of nuclides. Illustrative calculated results are given and comparisons are made with measured thick target yields and spectra. 50 refs., 1 fig., 2 tabs

  13. Relationship between age and peripapillary retinal nerve fibre layer thickness: an optical coherence tomography study.

    Science.gov (United States)

    Wong, I Y H; Wong, A C M; Chan, C W N

    2010-08-01

    To evaluate the relationship between age and peripapillary retinal nerve fibre layer thickness in healthy Chinese subjects. Cross-sectional study. Regional hospital, Hong Kong. Healthy volunteers (n=218) of Chinese ethnicity with spherical equivalent of -6 to +4 dioptres were recruited for study from October 2001 to March 2003. Ocular examination was carried out and measurements of peripapillary retinal nerve fibre layer thickness were performed using optical coherence tomography (Carl Zeiss Humphrey OCT 2 machine), in a circular pattern of 3.4 mm diameter, centred on the optic disc. Mean retinal nerve fibre layer thickness and age. The mean age was 40 (standard deviation, 17; range, 11-69) years. The mean peripapillary retinal nerve fibre layer thickness was 111.6 (standard deviation, 18.5; range, 52.0-155.0) micrometres. Age correlated significantly with peripapillary retinal nerve fibre layer thickness (r= -0.28, Pfibre layer thickness (based on optical coherence tomography) correlates negatively with age, which can interfere with the assessment and monitoring of glaucoma patients. An age-adjusted normogram may be necessary to interpret results.

  14. Peripapillary Scleral Thickness in Perfusion-Fixed Normal Monkey Eyes

    Science.gov (United States)

    Downs, J. Crawford; Blidner, Richard A.; Bellezza, Anthony J.; Thompson, Hilary W.; Hart, Richard T.; Burgoyne, Claude F.

    2009-01-01

    Purpose To characterize the thickness of the peripapillary sclera in perfusion-fixed normal monkey eyes so as to build accurate computational models of intraocular pressure (IOP)-related stress and strain within these tissues. Methods Nine rhesus monkeys were perfusion fixed, each with one normal eye set to an IOP of 10 mm Hg by manometer. A 6-mm-diameter specimen containing the optic nerve head and peripapillary sclera was trephined from each scleral shell and cut into 4-μm serial sagittal sections across the scleral canal opening, either horizontally (four eyes) or vertically (five eyes). The thickness of the peripapillary sclera was measured on every 24th section at 100-μm intervals from the posterior scleral canal opening (PSCO) to the peripheral edge of the specimen. The data were pooled by quadrant (superior, inferior, nasal, and temporal), regions within each quadrant, and distance from the PSCO, overall and for individual eyes, and subjected to analysis of variance. Results In terms of distance from the PSCO, the peripapillary sclera was thinnest nearest the PSCO (201 μm, nasal; 201 μm, temporal; 240 μm, inferior; 249 μm, superior), thickened progressively to a maximum in the midperiphery approximately 600 to 1000 μm from the PSCO (326 μm, nasal; 415 μm, superior; 420 μm, temporal; 422 μm, inferior), and thinned again peripherally in all quadrants. The peripapillary sclera was thinner in the nasal quadrant when compared with the other quadrants superiorly, inferiorly, and temporally (central region means of 291 μm, nasal; 369 μm, superior; 372 μm, inferior; and 369 μm, temporal; P < 0.0001). Conclusions In the normal monkey eye, peripapillary scleral thickness varies significantly with distance from the posterior scleral canal opening and is thinner in the nasal quadrant than in the other quadrants. These differences are substantial and are likely to affect the magnitude of IOP-related stress and strain within these tissues for a given level

  15. Skin thickness effects on in vivo LXRF

    International Nuclear Information System (INIS)

    Preiss, I.L.; Washington, W. II

    1995-01-01

    The analysis of lead concentration in bone utilizing LXRF can be adversely effected by overlying issue. A quantitative measure of the attenuation of the 10.5 keV Pb L a x-ray signal by skin and skin equivalent plastic has been conducted. Concentration ranges in plaster of Paris and goat bone from 7 to 90 ppm with attenuators of Lucite reg-sign and pig skin were examined. It is concluded that no quantitative or semi quantitative analysis can be achieved if overlying sue thickness exceeds 3 mm for Ph concentrations of less than 30 porn Ph in bone

  16. Cortical Thickness Changes Associated with Photoparoxysmal Response

    DEFF Research Database (Denmark)

    Hanganu, Alexandru; Groppa, Stanislav A; Deuschl, Günther

    2014-01-01

    Photoparoxysmal response (PPR) is an EEG trait of spike and spike-wave discharges in response to photic stimulation that is closely linked to idiopathic generalized epilepsy (IGE). In our previous studies we showed that PPR is associated with functional alterations in the occipital and frontal...... cortices. The aim of the present study was to determine structural changes associated with PPR. For this purpose we analysed the cortical thickness as derived from T1 MRI images in PPR-positive-subjects (n = 12; 15.5 ± 8.6 years; 4 males), PPR-positive-IGE-patients (n = 12; 14.9 ± 2.7 years; 4 males...

  17. Full-thickness endometriosis of the bladder

    DEFF Research Database (Denmark)

    Kjer, Jens Jørgen; Kristensen, Jens; Hartwell, Dorthe

    2014-01-01

    OBJECTIVE: To draw attention to the rare condition of endometriosis in the bladder. This is correlated with symptoms not normally connected to endometriosis and therefore often remains underdiagnosed for years. DESIGN AND SETTING: Retrospective study in a university teaching hospital, one of two...... and March 2011. We included only patients with symptomatic full-thickness bladder detrusor endometriosis and mucosal involvement. All patients had had bladder symptoms for two to seven years. MAIN OUTCOME MEASURES: Symptoms after surgery and recurrence rate. RESULTS: The main preoperative symptom...

  18. Uncertainties of the ultrasonic thickness gauging (UTTG)

    International Nuclear Information System (INIS)

    Mohamad Pauzi Ismail; Yassir Yassen; Amry Amin Abas

    2009-04-01

    The reliability of UTTG was questioned by a senior staff from DOSH in his paper presented during third NDT and Corrosion Management Asia Conference and Exhibition, 4-5 September 2007 at Istana Hotel, Kuala Lumpur. A term 'thickness grow' is an issue need to be solved by NDT community. The technique used by many practitioners gives rise to serious shortcoming in both probability of detection and accuracy of remaining wall assessment. This paper explained and discussed on uncertainty measurement based on the ISO Guide to the Expression of Uncertainty in Measurement (GUM) (1) of real UTTG data obtained from chemical industry. (author)

  19. Cement thickness measurements in cased boreholes

    International Nuclear Information System (INIS)

    Wahl, J.S.; Schuster, N.A.

    1978-01-01

    Methods and apparatus are provided for logging a borehole having solid matter along at least a portion of the wall thereof. Gamma radiation is emitted from the borehole into the surrounding media, and the amount of radiation which returns to the borehole is measured by three detectors located at different distances from the source of radiation, so as to be primarily sensitive to radiation which has respectively penetrated to three different depths in the surrounding media. The thickness of the solid matter on the borehole wall is then determined from the three gamma radiation measurements

  20. Endoscopic full-thickness resection: Current status.

    Science.gov (United States)

    Schmidt, Arthur; Meier, Benjamin; Caca, Karel

    2015-08-21

    Conventional endoscopic resection techniques such as endoscopic mucosal resection or endoscopic submucosal dissection are powerful tools for treatment of gastrointestinal neoplasms. However, those techniques are restricted to superficial layers of the gastrointestinal wall. Endoscopic full-thickness resection (EFTR) is an evolving technique, which is just about to enter clinical routine. It is not only a powerful tool for diagnostic tissue acquisition but also has the potential to spare surgical therapy in selected patients. This review will give an overview about current EFTR techniques and devices.

  1. Split-thickness skin grafting: early outcomes of a clinical trial using different graft thickness.

    Science.gov (United States)

    Guogienė, Inga; Kievišas, Mantas; Grigaitė, Augustina; Braziulis, Kęstutis; Rimdeika, Rytis

    2018-01-02

    In clinical practice, split-thickness skin graft (STSG) transplantation remains the gold standard for covering large skin defects. Currently, there is no consensus on the optimal thickness of skin grafts. The purpose of our study was to compare the early healing processes of recipient and donor wounds after STSG transplantation using grafts of different thickness. This prospective, randomised clinical trial included 84 patients that underwent STSG transplantation surgery for post-burn, post-traumatic or postoperative skin defects. Patients were randomised to receive a skin graft of either 0.2mm, 0.3mm or 0.4mm thickness. After skin transplantation, the wound healing parameters of both the recipient and donor wounds were evaluated after three days, one week, two weeks and one month. The greatest mean epithelialisation scores and highest rate of complete wound epithelialisation were identified in the recipient and donor wounds of the 0.2mm transplant group, at all time points. When the recipient wound pain scores were evaluated, the greatest visual analogue scale (VAS) values were found in the 0.2mm transplant group. The opposite result was found for the donor wound, where the highest VAS scores were identified in the 0.4mm transplant group. There were no significant differences, at any follow-up period, when wound secretion, erythema, swelling, localised warmth and fluctuation were compared. The early healing of recipient wounds after STSG transplantation with grafts of various thickness differed considerably, especially regarding wound epithelialisation and pain.

  2. Application of Industrial XRF Coating Thickness Analyzer for Phosphate Coating Thickness on Steel

    Directory of Open Access Journals (Sweden)

    Aleksandr Sokolov

    2018-03-01

    Full Text Available The results of industrial application of an online X-ray fluorescence coating thickness analyzer for measuring the thickness of phosphate coatings on moving steel strips are considered in the article. The target range of coating thickness to be measured is from tens to hundreds of mg/m2 in a measurement time of 10 s. The measurement accuracy observed during long-duration factory acceptance test was 10–15%. The coating thickness analyzer consists of two XRF gauges, mounted above and below the steel strip and capable of moving across the moving strip system for their suspension and relocation and electronic control unit. Fully automated software was developed to automatically and continuously (24/7 control both gauges, scanning both sides of the steel strip, and develop and test methods for measuring new coatings. It allows performing offline storage and retrieval of the measurement results, remotely controlling the analyzer components and measurement modes from a control room. The developed XRF coating thickness analyzer can also be used for real-time measurement of other types of coatings, both metallic and non-metallic.

  3. Altered cortical thickness and attentional deficits in adolescent girls and women with bulimia nervosa.

    Science.gov (United States)

    Berner, Laura A; Stefan, Mihaela; Lee, Seonjoo; Wang, Zhishun; Terranova, Kate; Attia, Evelyn; Marsh, Rachel

    2018-05-01

    Frontostriatal and frontoparietal abnormalities likely contribute to deficits in control and attentional processes in individuals with bulimia nervosa and to the persistence of dysregulated eating across development. This study assessed these processes and cortical thickness in a large sample of adolescent girls and women with bulimia nervosa compared with healthy controls. We collected anatomical MRI data from adolescent girls and women (ages 12-38 yr) with full or subthreshold bulimia nervosa and age-matched healthy controls who also completed the Conners Continuous Performance Test-II (CPT-II). Groups were compared on task performance and cortical thickness. Mediation analyses explored associations among cortical thickness, CPT-II variables, bulimia nervosa symptoms and age. We included 60 girls and women with bulimia nervosa and 54 controls in the analyses. Compared with healthy participants, those with bulimia nervosa showed increased impulsivity and inattention on the CPT-II, along with reduced thickness of the right pars triangularis, right superior parietal and left dorsal posterior cingulate cortices. In the bulimia nervosa group, exploratory analyses revealed that binge eating frequency correlated inversely with cortical thickness of frontoparietal and insular regions and that reduced frontoparietal thickness mediated the association between age and increased symptom severity and inattention. Binge eating frequency also mediated the association between age and lower prefrontal cortical thickness. These findings are applicable to only girls and women with bulimia nervosa, and our cross-sectional design precludes understanding of whether cortical thickness alterations precede or result from bulimia nervosa symptoms. Structural abnormalities in the frontoparietal and posterior cingulate regions comprising circuits that support control and attentional processes should be investigated as potential contributors to the maintenance of bulimia nervosa and useful

  4. Altered cortical thickness and attentional deficits in adolescent girls and women with bulimia nervosa.

    Science.gov (United States)

    Berner, Laura A; Stefan, Mihaela; Lee, Seonjoo; Wang, Zhishun; Terranova, Kate; Attia, Evelyn; Marsh, Rachel

    2018-01-12

    Frontostriatal and frontoparietal abnormalities likely contribute to deficits in control and attentional processes in individuals with bulimia nervosa and to the persistence of dysregulated eating across development. This study assessed these processes and cortical thickness in a large sample of adolescent girls and women with bulimia nervosa compared with healthy controls. We collected anatomical MRI data from adolescent girls and women (ages 12-38 yr) with full or subthreshold bulimia nervosa and age-matched healthy controls who also completed the Conners Continuous Performance Test-II (CPT-II). Groups were compared on task performance and cortical thickness. Mediation analyses explored associations among cortical thickness, CPT-II variables, bulimia nervosa symptoms and age. We included 60 girls and women with bulimia nervosa and 54 controls in the analyses. Compared with healthy participants, those with bulimia nervosa showed increased impulsivity and inattention on the CPT-II, along with reduced thickness of the right pars triangularis, right superior parietal and left dorsal posterior cingulate cortices. In the bulimia nervosa group, exploratory analyses revealed that binge eating frequency correlated inversely with cortical thickness of frontoparietal and insular regions and that reduced frontoparietal thickness mediated the association between age and increased symptom severity and inattention. Binge eating frequency also mediated the association between age and lower prefrontal cortical thickness. These findings are applicable to only girls and women with bulimia nervosa, and our cross-sectional design precludes understanding of whether cortical thickness alterations precede or result from bulimia nervosa symptoms. Structural abnormalities in the frontoparietal and posterior cingulate regions comprising circuits that support control and attentional processes should be investigated as potential contributors to the maintenance of bulimia nervosa and useful

  5. Thick accretion disks around black holes

    International Nuclear Information System (INIS)

    Paczynski, B.

    1982-01-01

    Theory of thick low viscosity disks accreting onto black holes is reviewed. Usefulness of a simplified pseudo-Newtonian potential for studies of disk models is emphasized. It is shown how very high accretion rate leads to a large disk thickness, large pressure gradients in the radial direction, formation of a narrow open funnel around the rotation axis, and a decrease of efficiency of convertion of rest mass into radiation. It is possible that the well collimated powerful radiation beam emerging from the funnel may accelerate some gas to moderately relativistic velocity in a form of a twin jet. The process is not efficient if the funnel is optically thin, but it is hoped that large optical depth of gas in the funnel may increase the fraction of total power coming out as kinetic energy of the jet. This class of models may be applied to SS 433, and possibly to other compact X-ray sources like Sco X-1 and Cyg X-1. These models may be relevant to some active galactic nuclei, but their relatively low efficiency in converting mass to radiation and kinetic energy does not permit too universal application. (orig.)

  6. Coating Thickness of the LHC Superconducting Strands

    CERN Document Server

    Charras, N

    2003-01-01

    In order to determine the time of heat treatment to give to the superconducting Rutherford-type cable, it is essential to know the stabrite (SnAg5%) coating thickness on the superconducting strands. Depending on the heat treatment time applied, the cable will have a contact resistance between strands conform to the LHC specifications. A study on the tin layers thickness was carried out. It concerns the internal and the external strands for all the firms producing these strands for the LHC. The level of control of the tinning process was established for each firm, and correlations between different measuring techniques of the tin layers were achieved, based on the keys process parameters. Finally, a correlation's relationship was found to get an equivalent value of Atomic Adsorption Spectrometry (AAS) from a coulometric result. The AAS measurement gives the total amount of tin in the strand and is the reference nowadays. Thanks to this equivalence, the number of real AAS measurements carried out can be lowered...

  7. Electron beam curable polymer thick film

    International Nuclear Information System (INIS)

    Nagata, Hidetoshi; Kobayashi, Takashi

    1988-01-01

    Currently, most printed circuit boards are produced by the selective etching of copper clads laminated on dielectric substrates such as paper/phenolic resion or nonwoven glass/epoxy resin composites. After the etchig, various components such as transistors and capacitors are mounted on the boards by soldering. But these are troublesome works, therefore, as an alternative, printing method has been investigated recently. In the printing method, conductor circuits and resistors can be made by printing and curing of the specially prepared paste on dielectric substrates. In the near future, also capacitors are made by same method. Usually, conductor paste, resistor paste and dielectric paste are employed, and in this case, the printing is screen printing, and the curing is done thermally. In order to avoid heating and the deterioration of substrates, attention was paid to electron beam curing, and electron beam curable polymer thick film system was developed. The electron beam curable paste is the milled mixture of a filler and an electron beam curable binder of oligomer/monomer. The major advantage of electron beam curable polymer thick film, the typical data of a printed resistor of this type and its trial are reported. (K.I.)

  8. THREE-DIMENSIONAL OBSERVATIONS ON THICK BIOLOGICAL SPECIMENS BY HIGH VOLTAGE ELECTRON MICROSCOPY

    Directory of Open Access Journals (Sweden)

    Tetsuji Nagata

    2011-05-01

    Full Text Available Thick biological specimens prepared as whole mount cultured cells or thick sections from embedded tissues were stained with histochemical reactions, such as thiamine pyrophosphatase, glucose-6-phosphatase, cytochrome oxidase, acid phosphatase, DAB reactions and radioautography, to observe 3-D ultrastructures of cell organelles producing stereo-pairs by high voltage electron microscopy at accerelating voltages of 400-1000 kV. The organelles demonstrated were Golgi apparatus, endoplasmic reticulum, mitochondria, lysosomes, peroxisomes, pinocytotic vesicles and incorporations of radioactive compounds. As the results, those cell organelles were observed 3- dimensionally and the relative relationships between these organelles were demonstrated.

  9. Thickness characterisation of oil spills using active microwave sensors

    Science.gov (United States)

    True, Michael; Shuchman, Robert A.; Kletzli, D. W., Jr.; Johannessen, Johnny A.; Digranes, Gunar; Berg, Sverre; Dalland, Kjell

    1994-12-01

    Oil thickness is a crucial parameter in the characterization of oil spills for environmental impact. The feasibility of using active microwave sensors to measure thickness was addressed in a series of microwave scatterometer experiments performed by Simrad Marine A/S in a wave tank at the Nansen Environmental Remote Sensing Center. The thickness of the oil layer was maintained at levels similar to the thick part of an oil spill (0.1 - 1 mm). The measurements showed the capability of active microwave sensors to measure oil spill thickness when the oil type is known. In addition to thickness characterization, the experiment studied the effects of oil viscosity, incidence angle, wind speed, wind angle, microwave frequency, and polarization. The backscatter contrast was observed to be greater for lower incidence angles which indicates that the ERS-1 viewing geometry is optimum for the detection and measurement of thick oil slicks. A thickness-dependent backscatter model was developed which included the effects of oil viscosity, composite surface effects, and oil-water reflectivities. The model viscous effects saturated when the oil thickness was greater than the viscous boundary layer thickness. This explained the observed C-VV backscatter contrast saturation for low viscosity diesel oil at thicknesses greater than 0.15 mm. The model predicted contrast saturation at greater thicknesses for the higher viscosity oils. The data showed this trend but the measurements did not extend to thicknesses which tested the model completely.

  10. Manual for target thickness measurement by alpha particle irradiation

    International Nuclear Information System (INIS)

    Dias, J.F.; Martins, M.N.

    1990-04-01

    A system is described for thin-target thickness measurement through the alpha particle energy loss when them traverse the target. It is also described the program used in the analysis of the target thickness. (L.C.) [pt

  11. Influence of biofilm thickness on micropollutants removal in nitrifying MBBRs

    DEFF Research Database (Denmark)

    Torresi, Elena; Andersen, Henrik Rasmus; Smets, Barth F.

    The removal of pharmaceuticals was investigated in nitrifying Moving Bed Biofilm Reactors (MBBRs) containing carriers with different biofilm thicknesses. The biofilm with the thinnest thickness was found to have the highest nitrification and biotransformation rate for some key pharmaceuticals. Mi...

  12. Radiation phantom with humanoid shape and adjustable thickness

    Science.gov (United States)

    Lehmann, Joerg [Pleasanton, CA; Levy, Joshua [Salem, NY; Stern, Robin L [Lodi, CA; Siantar, Christine Hartmann [Livermore, CA; Goldberg, Zelanna [Carmichael, CA

    2006-12-19

    A radiation phantom comprising a body with a general humanoid shape and at least a portion having an adjustable thickness. In one embodiment, the portion with an adjustable thickness comprises at least one tissue-equivalent slice.

  13. Charpy impact test results of ferritic alloys at a fluence of 6 x 1022n/cm2

    International Nuclear Information System (INIS)

    Hu, W.L.

    1985-01-01

    Charpy impact tests on specimens in the AD-2 reconstitution experiment were completed. One hundred ten specimens made of HT-9 base metal, 9Cr-1Mo base metal and 9Cr-1Mo weldment at various heat treatment conditions were tested in temperature range from -73 0 C to 260 0 C. The specimens were irradiated from 390 0 C to 550 0 C and the fluence of the specimens reached 6 x 10 22 n/cm 2 . This is the first time that the transition behavior of ferritic alloys at high fluence was obtained. This is also the first time that comprehensive results on the irradiated 9Cr-1Mo weldment are available. The test results show a small additional shift in transition temperature for HT-9 base metal irradiated at 390 0 C and 450 0 C as the fluence was raised to 6 x 10 22 n/cm 2 . At higher irradiation temperatures, however, the shift in transition temperature is less conclusive. Further reduction in USE was observed at higher fluence for all the irradiation temperatures. There is no apparent fluence effect for 9Cr-1Mo base metal at all the irradiation temperatures studied. Contrary to the previous finding on HT-9 base metal and weldment, the 9Cr-1Mo weldment shows a higher transition temperature ( + 60 0 C) and a higher USE ( + 100%) as compared to the 9Cr-1MO base metal for the same irradiation conditions. 6 references, 7 figures, 7 tables

  14. Comparison of the mechanical strength properties of several high-chromium ferritic steels

    International Nuclear Information System (INIS)

    Booker, M.K.; Sikka, V.K.; Booker, B.L.P.

    1983-01-01

    A modified 9 Cr-1 Mo ferritic steel has been selected for development by the US Department of Energy as an alternative structural material for breeder reactor applications in which type 304 stainless steel or 2 1/4 Cr-1 Mo steel is currently being used. This developmental alloy is a modification (primarily through additions of niobium and vanadium) of a commercial 9 Cr-1 Mo steel already available in the US. A similar commercial alloy is available in the UK. Meanwhile, a 9 Cr-2 Mo alloy (EM12) is now used in France and a 12 Cr-1 Mo alloy (HT9) has been recommended for high temperature service in both Europe and the US. This paper compares the yield strength and ultimate tensile strength properties of the American modified 9 Cr-1 Mo steel with those of the American and British commercial 9 Cr-1 Mo steels. In addition, the creep rupture properties of the modified alloy are compared with those of the two commercial 9 Cr-1 Mo steels, 2 1/4 Cr-1 Mo steel, HT9, EM12, and type 304 stainless steel. The overall conclusion of the study is that the modified 9 Cr-1 Mo steel displays tensile and creep strengths matching or exceeding those of the other ferritic materials examined, and being at least comparable to those of type 304 stainless steel from room temperature to about 625 0 C. 15 references, 11 figures, 3 tables

  15. The thickness of the interplanetary collisionless shock waves

    International Nuclear Information System (INIS)

    Pinter, S.

    1980-05-01

    The thicknesses of magnetic structures of the interplanetary shock waves related to the upstream solar wind plasma parameters are studied. From this study the following results have been obtained: the measured shock thickness increases for decreasing upstream proton number density and decreases for increasing proton flux energy. The shock thickness strongly depends on the ion plasma β, i.e. for higher values of the β the thickness decreases. (author)

  16. A simplified procedure for preparation of undecalcified human bone sections

    DEFF Research Database (Denmark)

    Wallin, J A; Tkocz, I; Levinsen, J

    1985-01-01

    A new type of apparatus for sectioning samples of hard, undecalcified bone is described. Slices of fresh or archeological human bone 4-5 mm thick are dehydrated and then embedded in epoxy resin. The apparatus used to prepare sections from the resulting blocks consists of a low-speed rim...

  17. A simplified procedure for preparation of undecalcified human bone sections

    DEFF Research Database (Denmark)

    Wallin, J A; Tkocz, I; Levinsen, J

    1985-01-01

    A new type of apparatus for sectioning samples of hard, undecalcified bone is described. Slices of fresh or archeological human bone 4-5 mm thick are dehydrated and then embedded in epoxy resin. The apparatus used to prepare sections from the resulting blocks consists of a low-speed rim-type...

  18. Reduced cortical thickness in gambling disorder

    DEFF Research Database (Denmark)

    Grant, Jon E; Odlaug, Brian Lawrence; Chamberlain, Samuel R

    2015-01-01

    Gambling disorder has recently been recognized as a prototype 'behavioral addiction' by virtue of its inclusion in the DSM-5 category of 'Substance-Related and Addictive Disorders.' Despite its newly acquired status and prevalence rate of 1-3 % globally, relatively little is known regarding...... the neurobiology of this disorder. The aim of this study was to explore cortical morphometry in untreated gambling disorder, for the first time. Subjects with gambling disorder (N = 16) free from current psychotropic medication or psychiatric comorbidities, and healthy controls (N = 17), were entered...... into the study and undertook magnetic resonance imaging (3T MRI). Cortical thickness was quantified using automated segmentation techniques (FreeSurfer), and group differences were identified using permutation cluster analysis, with stringent correction for multiple comparisons. Gambling disorder was associated...

  19. Critical currents of variable thickness bridges

    International Nuclear Information System (INIS)

    Lapir, G.M.; Likharev, K.K.; Maslova, L.A.; Semenov, V.K.

    1975-01-01

    A variable thickness bridge (VTB) is a short strip of thin normal or superconducting electrodes - 'banks'. This type of weak link has the peculiarity of having the changes of the modulus of the orderparameter localized in the film of the bridge. Only changes of the phase of the orderparameter take place in the banks, and so the electrodynamics of the banks is linear. The problem of the distribution of the linear density of current Jsub(s)(psi) and of the phase difference of the banks psi along the VTB width is considered and the critical current Isub(c) for the important case of a VTB deposited over a superconducting ground plate - 'screen' is calculated. (Auth.)

  20. Measuring coating thicknesses on continuously moving material

    International Nuclear Information System (INIS)

    Holler, J.H.; Stanton, W.B.; Spongr, J.J.; Joffe, B.B.; Raffelsberger, P.W.; Tiebor, J.E.

    1982-01-01

    A method and apparatus using radiation techniques for measuring coating thicknesses on continuously moving strip material without altering a predetermined path along which it travels. A shuttle carrying a measuring probe having a radioactive isotope source and a detection device is provided for reciprocation along a preselected segment of the path of the strip. The shuttle and the probe are releasably engaged with the strip and carried thereby for synchronous movement therewith in the forward direction during a measurement cycle, and are disengaged from the strip when no measurement is being made, the movement of the shuttle then being controlled by an independent drive mechanism, shown as a belt drive, which reciprocates the shuttle along the rails. A belt drives it forward more slowly than the strip, which then engages the shuttle to pull it at strip speed, allowed by a pulley clutch. (author)

  1. Free Vibration of Thick Multilayer Cylinders

    Directory of Open Access Journals (Sweden)

    H. R. Hamidzadeh

    1995-01-01

    Full Text Available In this study of the free vibration of multilayer thick cylinders, the medium is modeled by laminated linear viscoelastic cylinders of an infinite extent. The analytical modeling is based on three-dimensional wave propagation utilizing constant complex elastic moduli. The solution is achieved by determining the displacements and stresses for each interface and by complying with requirements at the interfaces. A propagator matrix relating the boundary displacements to boundary stresses is developed. Dimensionless natural frequencies and modal loss factors for different circumferential and axial wave numbers are determined. The validity of the proposed method is verified by comparing the results for one-, two-, and three-layer elastic cylinders with properties similar to those reported for an equivalent single layer.

  2. On thick domain walls in general relativity

    Science.gov (United States)

    Goetz, Guenter; Noetzold, Dirk

    1989-01-01

    Planar scalar field configurations in general relativity differ considerably from those in flat space. It is shown that static domain walls of finite thickness in curved space-time do not possess a reflection symmetry. At infinity, the space-time tends to the Taub vacuum on one side of the wall and to the Minkowski vacuum (Rindler space-time) on the other. Massive test particles are always accelerated towards the Minkowski side, i.e., domain walls are attractive on the Taub side, but repulsive on the Minkowski side (Taub-vacuum cleaner). It is also proved that the pressure in all directions is always negative. Finally, a brief comment is made concerning the possibility of infinite, i.e., bigger than horizon size, domain walls in our universe. All of the results are independent of the form of the potential V(phi) greater than or equal to 0 of the scalar field phi.

  3. Advanced Metrologies for Topography and Thickness Measurements

    Science.gov (United States)

    Riou, G.; Acosta, P.; Darwin, M.; Kamenev, B.

    2011-11-01

    Despite its limitations, like the low through put, Atomic force microscopy (AFM) is in common use in the semiconductor industry for surface geometry characterization. Recent development in optical profilometry, Index Corrected Topography (ICT), further expands the technique by analysis of the collected interferograms to extract films parameters (thickness, for instance) and surface topography. This model based technique delivers literally complete information (e.g. topography, roughness, filmstack properties) of measured structure with sub-micron lateral resolution and angstrom vertical resolution. The approach is a strong asset since it allows contact less topography measurement of wafer surfaces. In this paper we will show how this specific metrology can meet the aforementioned stringent requirements. The comparison with both the AFM and the spectroscopic ellipsometry will be presented.

  4. Thick-film analysis: literature search and bibliography

    International Nuclear Information System (INIS)

    Gehman, R.W.

    1981-09-01

    A literature search was conducted to support development of in-house diagnostic testing of thick film materials for hybrid microcircuits. A background literature review covered thick film formulation, processing, structure, and performance. Important material properties and tests were identified and several test procedures were obtained. Several tests were selected for thick film diagnosis at Bendix Kansas City. 126 references

  5. Optimal thickness calculation of cobalt targets in HFETR

    International Nuclear Information System (INIS)

    Liu Shuiqing; Peng Feng

    1995-01-01

    The ANISN code, which is more exact than 'blacken-theory', is used to calculate the thickness of cobalt targets of 'sandwich' type structure in HFETR core. Result shows: there is a wide radioactivity peak when the cobalt thickness is between 2.5 mm and 3.0 mm, the optimal thickness of maximum's radioactivity is about 2.9 mm

  6. Free and Forced Vibrations of Thick-Walled Anisotropic Cylindrical Shells

    Science.gov (United States)

    Marchuk, A. V.; Gnedash, S. V.; Levkovskii, S. A.

    2017-03-01

    Two approaches to studying the free and forced axisymmetric vibrations of cylindrical shell are proposed. They are based on the three-dimensional theory of elasticity and division of the original cylindrical shell with concentric cross-sectional circles into several coaxial cylindrical shells. One approach uses linear polynomials to approximate functions defined in plan and across the thickness. The other approach also uses linear polynomials to approximate functions defined in plan, but their variation with thickness is described by the analytical solution of a system of differential equations. Both approaches have approximation and arithmetic errors. When determining the natural frequencies by the semi-analytical finite-element method in combination with the divide and conqure method, it is convenient to find the initial frequencies by the finite-element method. The behavior of the shell during free and forced vibrations is analyzed in the case where the loading area is half the shell thickness

  7. Nondestructive measurement of homoepitaxially grown GaN film thickness with Fourier transform infrared spectroscopy

    Science.gov (United States)

    Horikiri, Fumimasa; Narita, Yoshinobu; Yoshida, Takehiro

    2017-12-01

    In vertical devices containing GaN homoepitaxial layers on GaN substrates, the layer thickness is a key parameter that needs to be clarified before starting the device process. We applied Fourier transform infrared spectroscopy (FT-IR) to a homoepitaxially grown GaN film that consisted of an n--GaN layer. The estimated film thickness from the FT-IR spectrum agreed well with the results of cross-sectional scanning electron microscope cathodoluminescence images. This is the first report of nondestructive film thickness measurements for homoepitaxially grown GaN and indicates the applicability of FT-IR to the nondestructive inspection of vertical GaN power devices.

  8. Plantar fascia segmentation and thickness estimation in ultrasound images.

    Science.gov (United States)

    Boussouar, Abdelhafid; Meziane, Farid; Crofts, Gillian

    2017-03-01

    Ultrasound (US) imaging offers significant potential in diagnosis of plantar fascia (PF) injury and monitoring treatment. In particular US imaging has been shown to be reliable in foot and ankle assessment and offers a real-time effective imaging technique that is able to reliably confirm structural changes, such as thickening, and identify changes in the internal echo structure associated with diseased or damaged tissue. Despite the advantages of US imaging, images are difficult to interpret during medical assessment. This is partly due to the size and position of the PF in relation to the adjacent tissues. It is therefore a requirement to devise a system that allows better and easier interpretation of PF ultrasound images during diagnosis. This study proposes an automatic segmentation approach which for the first time extracts ultrasound data to estimate size across three sections of the PF (rearfoot, midfoot and forefoot). This segmentation method uses artificial neural network module (ANN) in order to classify small overlapping patches as belonging or not-belonging to the region of interest (ROI) of the PF tissue. Features ranking and selection techniques were performed as a post-processing step for features extraction to reduce the dimension and number of the extracted features. The trained ANN classifies the image overlapping patches into PF and non-PF tissue, and then it is used to segment the desired PF region. The PF thickness was calculated using two different methods: distance transformation and area-length calculation algorithms. This new approach is capable of accurately segmenting the PF region, differentiating it from surrounding tissues and estimating its thickness. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Normative spectral domain optical coherence tomography data on macular and retinal nerve fiber layer thickness in Indians

    Directory of Open Access Journals (Sweden)

    Bindu Appukuttan

    2014-01-01

    Full Text Available Aim: To provide the normative data of macular and retinal nerve fiber layer (RNFL thickness in Indians using spectral domain OCT (Spectralis OCT, Heidelberg Engineering, Germany and to evaluate the effects of age, gender, and refraction on these parameters. Design: Observational, cross-sectional study. Materials and Methods: The eyes of 105 healthy patients aged between 20-75 years, with no ocular disease and best corrected visual acuity of 20/20, were scanned using standard scanning protocols by a single examiner. Exclusion criteria included glaucoma, retinal diseases, diabetes, history of prior intraocular surgery or laser treatment. The mean macular and RNFL thickness were recorded, and the effects of age, gender, and refraction on these parameters were evaluated. This data was compared with published literature on Caucasians to assess the ethnic variations of these parameters. Results: The normal central foveal thickness in healthy Indian eyes measured using Spectralis OCT was 260.1 ± 18.19 ΅m. The nasal inner quadrant showed maximum retinal thickness (338.88 ± 18.17 ΅m.The mean RNFL thickness was 101.43 ± 8.63 ΅m with maximum thickness in the inferior quadrant. The central foveal thickness showed a gender-based difference (P = 0.005 but did not correlate significantly with age (P = 0.134, whereas the parafoveal, perifoveal thickness, macular volume, and RNFL thickness showed significant negative correlation with age. Conclusions: Our study provides the normative database for Indians on Spectralis OCT. It also suggests that age should be considered while interpreting the macular thickness and RNFL, whereas gender should also be given consideration in central foveal thickness.

  10. Influence of slice thickness on the determination of left ventricular wall thickness and dimension by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Shusaku; Fukui, Sugao; Atsumi, Chisato and others

    1989-02-01

    Wall thickness of the ventricular septum and left ventricle, and left ventricular cavity dimension were determined on magnetic resonance (MR) images with slices 5 mm and 10 mm in thickness. Subjects were 3 healthy volunteers and 7 patients with hypertension (4), hypertrophic cardiomyopathy (one) or valvular heart disease (2). In visualizing the cardiac structures such as left ventricular papillary muscle and right and left ventricles, 5 mm-thick images were better than 10 mm-thick images. Edges of ventricular septum and left ventricular wall were more clearly visualized on 5 mm-thick images than 10 mm-thick images. Two mm-thick MR images obtained from 2 patients yielded the most excellent visualization in end-systole, but failed to reveal cardiac structures in detail in end-diastole. Phantom studies revealed no significant differences in image quality of 10 mm and 5 mm in thickness in the axial view 80 degree to the long axis. In the axial view 45 degree to the long axis, 10 mm-thick images were inferior to 5 mm-thick images in detecting the edge of the septum and the left ventricular wall. These results indicate that the selection of slice thickness is one of the most important determinant factors in the measurement of left ventricular wall thickness and cavity dimension. (Namekawa, K).

  11. Survey of Nerve Fiber Layer Thickness in Anisometropic and Strabismic Amblyopia

    Directory of Open Access Journals (Sweden)

    Reza Soltani Moghaddam

    2017-02-01

    Full Text Available . To investigate the effect of anisometropic and strabismic amblyopia on the nerve fiber layer thickness. This cross-sectional study was done on 54 amblyopic subjects, equally in both strabismic and anisometropic groups. The thickness otonerve fiber layer measured in superior, inferior, nasal, temporal quadrants and as a whole in both eyes of both groups. The means of thickness were compared in amblyopic and sound eyes. In strabismus group, the average nerve fiber layer thickness of the sound eye , in superior, inferior, nasal and temporal quadrants and as a whole were 113.23±14, 117.37±25, 68.96±6, 69.55±14 and 93.40±8 microns respectively. In amblyopic eyes of the same group, these measurements were 103.11±18, 67.74±11, and 69.59±16 and 89.59±12 microns in superior, inferior, nasal, temporal quadrants and as whole respectively. In anisometropic groups, the sound eye measurements were as 130.96±22, 129.07±29, 80.62±12, and 83.88±20 and 107.7±13 microns in superior, inferior, nasal and temporal quadrants and as a whole orderly. In amblyopic eyes of this group the mean thicknesses were 115.63±29, 133.15±25, 78.8±15, 80.2±16 and 109.17±21 microns in superior, inferior, nasal, temporal quadrants and as a whole respectively. Statistically, there were no significant differences between amblyopic and sound eyes (P>0.5. Our study did not support any significant change in a nerve fiber layer thickness of amblyopic patients; however, decreased thickness in superior and nasal quadrants of strabismic amblyopia and except inferior quadrant and as a whole. These measurements may be a clue for management and prognosis of amblyopia in old age.

  12. Automated modelling of spatially-distributed glacier ice thickness and volume

    Science.gov (United States)

    James, William H. M.; Carrivick, Jonathan L.

    2016-07-01

    Ice thickness distribution and volume are both key parameters for glaciological and hydrological applications. This study presents VOLTA (Volume and Topography Automation), which is a Python script tool for ArcGISTM that requires just a digital elevation model (DEM) and glacier outline(s) to model distributed ice thickness, volume and bed topography. Ice thickness is initially estimated at points along an automatically generated centreline network based on the perfect-plasticity rheology assumption, taking into account a valley side drag component of the force balance equation. Distributed ice thickness is subsequently interpolated using a glaciologically correct algorithm. For five glaciers with independent field-measured bed topography, VOLTA modelled volumes were between 26.5% (underestimate) and 16.6% (overestimate) of that derived from field observations. Greatest differences were where an asymmetric valley cross section shape was present or where significant valley infill had occurred. Compared with other methods of modelling ice thickness and volume, key advantages of VOLTA are: a fully automated approach and a user friendly graphical user interface (GUI), GIS consistent geometry, fully automated centreline generation, inclusion of a side drag component in the force balance equation, estimation of glacier basal shear stress for each individual glacier, fully distributed ice thickness output and the ability to process multiple glaciers rapidly. VOLTA is capable of regional scale ice volume assessment, which is a key parameter for exploring glacier response to climate change. VOLTA also permits subtraction of modelled ice thickness from the input surface elevation to produce an ice-free DEM, which is a key input for reconstruction of former glaciers. VOLTA could assist with prediction of future glacier geometry changes and hence in projection of future meltwater fluxes.

  13. Survey of Nerve Fiber Layer Thickness in Anisometropic and Strabismic Amblyopia.

    Science.gov (United States)

    Soltani Moghaddam, Reza; Medghalchi, Abdolreza; Alizadeh, Yousef

    2017-01-01

    . To investigate the effect of anisometropic and strabismic amblyopia on the nerve fiber layer thickness. This cross-sectional study was done on 54 amblyopic subjects, equally in both strabismic and anisometropic groups. The thickness otonerve fiber layer measured in superior, inferior, nasal, temporal quadrants and as a whole in both eyes of both groups. The means of thickness were compared in amblyopic and sound eyes. In strabismus group, the average nerve fiber layer thickness of the sound eye , in superior, inferior, nasal and temporal quadrants and as a whole were 113.23±14, 117.37±25, 68.96±6, 69.55±14 and 93.40±8 microns respectively. In amblyopic eyes of the same group, these measurements were 103.11±18, 67.74±11, and 69.59±16 and 89.59±12 microns in superior, inferior, nasal, temporal quadrants and as whole respectively. In anisometropic groups, the sound eye measurements were as 130.96±22, 129.07±29, 80.62±12, and 83.88±20 and 107.7±13 microns in superior, inferior, nasal and temporal quadrants and as a whole orderly. In amblyopic eyes of this group the mean thicknesses were 115.63±29, 133.15±25, 78.8±15, 80.2±16 and 109.17±21 microns in superior, inferior, nasal, temporal quadrants and as a whole respectively. Statistically, there were no significant differences between amblyopic and sound eyes (P>0.5). Our study did not support any significant change in a nerve fiber layer thickness of amblyopic patients; however, decreased thickness in superior and nasal quadrants of strabismic amblyopia and except inferior quadrant and as a whole. These measurements may be a clue for management and prognosis of amblyopia in old age.

  14. Eruption and emplacement dynamics of a thick trachytic lava flow of the Sancy volcano (France)

    Science.gov (United States)

    Latutrie, Benjamin; Harris, Andrew; Médard, Etienne; Gurioli, Lucia

    2017-01-01

    A 70-m-thick, 2200-m-long (51 × 106 m3) trachytic lava flow unit underlies the Puy de Cliergue (Mt. Dore, France). Excellent exposure along a 400-m-long and 60- to 85-m-high section allows the flow interior to be accessed on two sides of a glacial valley that cuts through the unit. We completed an integrated morphological, structural, textural, and chemical analysis of the unit to gain insights into eruption and flow processes during emplacement of this thick silicic lava flow, so as to elucidate the chamber and flow dynamic processed that operate during the emplacement of such systems. The unit is characterized by an inverse chemical stratification, where there is primitive lava beneath the evolved lava. The interior is plug dominated with a thin basal shear zone overlying a thick basal breccia, with ramping affecting the entire flow thickness. To understand these characteristics, we propose an eruption model that first involves processes operating in the magma chamber whereby a primitive melt is injected into an evolved magma to create a mixed zone at the chamber base. The eruption triggered by this event first emplaced a trachytic dome, into which banded lava from the chamber base was injected. Subsequent endogenous dome growth led to flow down the shallow slope to the east on which the highly viscous (1012 Pa s) coulée was emplaced. The flow likely moved extremely slowly, being emplaced over a period of 4-10 years in a glacial manner, where a thick (>60-m) plug slid over a thin (5-m-thick) basal shear zone. Excellent exposure means that the Puy de Cliergue complex can be viewed as a case type location for understanding and defining the eruption and emplacement of thick, high-viscosity, silicic lava flow systems.

  15. Correlation Between Bone and Soft Tissue Thickness in Maxillary Anterior Teeth

    Directory of Open Access Journals (Sweden)

    Nasrin Esfahanizadeh

    2016-12-01

    Full Text Available Objectives: The purpose of this study was to determine buccal bone and soft tissue thicknesses and their correlation in the maxillary anterior region using cone beam computed tomography (CBCT.Materials and Methods: In this cross sectional study, 330 sound maxillary incisors in 60 patients with a mean age of 37.5 years were assessed by CBCT scans. For better visualization of soft tissue, patients were asked to use plastic retractors in order to retract their lips and cheeks away from the gingival tissue before taking the scans. Measurements were made in three different positions: at the crest and at 2 and 5mm apical to the crest. The cementoenamel junction‒crest distance was measured. for data analyses, the Pearson’s correlation coefficient, ANOVA and intraclass correlation coefficient were used.Results: There were mildly significant linear associations between labial soft tissue and bone thickness in the canines and incisors (r<0.40, P<0.05, but no association was found for the lateral incisors. The mean thickness of buccal bone differed significantly in the maxillary anterior teeth, being greater for the lateral incisors (P<0.05. For soft tissue thickness, the results were the same, and the least thickness was recorded for the canines. There was a mild association between labial soft tissue and bone thickness in canines and incisors (r=0.2, P=0.3, but no such linear association was seen for the lateral incisors.Conclusions: The mean thickness of buccal bone and soft tissue in the anterior maxilla was <1mm and there was a mild linear correlation between them.Keywords: Facial Bones; Cone-Beam Computed Tomography; Maxilla; Esthetics, Dental

  16. Modeling and characterization of through-the-thickness properties of 3D woven composites

    Science.gov (United States)

    Hartranft, Dru; Pravizi-Majidi, Azar; Chou, Tsu-Wei

    1995-01-01

    The through-the-thickness properties of three-dimensionally (3D) woven carbon/epoxy composites have been studied. The investigation aimed at the evaluation and development of test methodologies for the property characterization in the thickness direction, and the establishment of fiber architectures were studied: layer-to-layer Angle Interlock, through-the-thickness Orthogonal woven preform with surface pile was also designed and manufactured for the fabrication of tensile test coupons with integrated grips. All the preforms were infiltrated by the resin transfer molding technique. The microstructures of the composites were characterized along the warp and fill (weft) directions to determine the degree of yarn undulations, yarn cross-sectional shapes, and microstructural dimensions. These parameters were correlated to the fiber architecture. Specimens were designed and tested for the direct measurement of the through-the-thickness tensile, compressive and shear properties of the composites. Design optimization was conducted through the analysis of the stress fields within the specimen coupled with experimental verification. The experimentally-derived elastic properties in the thickness direction compared well with analytical predictions obtained from a volume averaging model.

  17. The Comparison of Dentine Thickness Under Proximal Caries Between Bitewing Radiographs and Tooth Structure

    Directory of Open Access Journals (Sweden)

    Khosravi K

    2001-05-01

    Full Text Available Carious lesions are usually found by dentists, using bitewing radiographs, and according to the depth of the lesions, the treatment plan is designed. At the present, this technique is the most accepted one and is used generally. But it is not a perfect technique and there are some errors in determining of depth of proximal carious lesions. These errors are mainly related to the use of new high-speed films with broad density and lower voltages. In this study, dentin thickness under proximal caries in bitewing radiography was compared with its real thickness, in tooth structure. Twenty-four teeth samples with proximal caries were used. Before and after removal of carious lesions bitewing radiographs were taken and then each tooth was sectioned occlusogingivally and the thickness of dentine under proximal caries and on bitewing radiographs were measured under microscope with 0.01 mm accuracy. Mean value of dentine thickness in tooth structure was 41% of its mean thickness in bitewing radiographs, showing 59% difference (reduction. Therefore, more care should be taken in using standard technique and interpreting of bitewing radiographs by clinicians. Clinical examinations also should be performed in ideal conditions, and patients should be clinically and radiographically examined every six months.

  18. Diode laser-based standoff absorption measurement of water film thickness in retro-reflection

    Science.gov (United States)

    Pan, R.; Brocksieper, C.; Jeffries, J. B.; Dreier, T.; Schulz, C.

    2016-09-01

    A dual-wavelength diode laser-based absorption sensor for standoff point measurements of water film thickness on an opaque surface is presented. The sensor consists of a diode laser source, a foil as backscattering target, and off-axis paraboloids for collecting the fraction of the laser radiation transmitted through the liquid layer via retro-reflection. Laser wavelengths in the near infrared at 1412 and 1353 nm are used where the temperature dependence of the liquid water absorption cross section is known. The lasers are fiber coupled and the detection of the retro-reflected light was accomplished through a multimode fiber and a single photodiode using time-division multiplexing. The water film thickness at a given temperature was determined from measured transmittance ratios at the two laser wavelengths. The sensor concept was first validated with measurement using a temperature-controlled calibration cell providing liquid layers of variable and known thickness between 100 and 1000 µm. Subsequently, the sensor was demonstrated successfully during recording the time-varying thickness of evaporating water films at fixed temperatures. The film thickness was recorded as a function of time at three temperatures down to 50 µm.

  19. Estimation of ultrasonic guided wave mode conversion in a plate with thickness variation.

    Science.gov (United States)

    Cho, Y

    2000-01-01

    The hybrid boundary element method aimed at analyzing Lamb wave scattering from defects can provide us with an excellent numerical tool for tackling complicated mode conversion phenomena under waveguide thickness variation. In this paper, utilization of hybrid boundary element modeling for specific Lamb wave mode incidence situations with special energy distributions along the structural cross section is proposed for estimating reflection and transmission from various scatterers, such as a step discontinuity and tapered parts of a waveguide, etc. Interaction of individual Lamb wave modes with scatterers that represent arbitrary thickness variation along the direction of guided wave propagation is investigated by calculating the scattered fields for varying incident modes, frequency, and scatterer shape. The mode conversion phenomena through step discontinuity in a plate are also experimentally explored. The theoretical predictions of reflection and transmission by boundary element methods and the utility of dispersion curves are compared with experiments for specific modes. Results in this paper can be used to improve inspection sensitivity and penetration power for a variety of practical NDE applications, notably those in which thickness variation is found. In addition, the feasibility of inspecting sections located behind a waveguide thickness variation region and subsequent mode control will also be discussed.

  20. Axial-torsional fatigue - A study of tubular specimen thickness effects

    Science.gov (United States)

    Bonacuse, Peter J.; Kalluri, Sreeramesh

    1993-01-01

    Experiments were carried out at room temperature on AISI type 316 stainless steel to determine the effect of wall thickness on the cyclic deformation behavior and fatigue life of thin-wall tubular axial-torsional fatigue specimens. The experimental variables examined included the depth of the surface work-hardened layer produced in specimen machining, and the effects of strain range and axial-torsional strain phasing. Tubular fatigue specimens had wall thicknesses of 1.5, 2.0, and 2.5 mm. One as-fabricated specimen from each wall thickness was sectioned for microstructural examination and microhardness measurement. A specimen of each wall thickness was tested in axial-torsional fatigue experiments for each of the three conditions: high strain range in-phase, low strain range in-phase, and low strain range out-of-phase. The machining-induced work-hardened zone, as a percentage of the gage section material, was found to have a minimal effect on both deformation behavior and fatigue life. Out-of-phase fatigue tests displayed shorter fatigue lives and more cyclic hardening than in-phase tests.

  1. Process stability during fiber laser-arc hybrid welding of thick steel plates

    Science.gov (United States)

    Bunaziv, Ivan; Frostevarg, Jan; Akselsen, Odd M.; Kaplan, Alexander F. H.

    2018-03-01

    Thick steel plates are frequently used in shipbuilding, pipelines and other related heavy industries, and are usually joined by arc welding. Deep penetration laser-arc hybrid welding could increase productivity but has not been thoroughly investigated, and is therefore usually limited to applications with medium thickness (5-15 mm) sections. A major concern is process stability, especially when using modern welding consumables such as metal-cored wire and advanced welding equipment. High speed imaging allows direct observation of the process so that process behavior and phenomena can be studied. In this paper, 45 mm thick high strength steel was welded (butt joint double-sided) using the fiber laser-MAG hybrid process utilizing a metal-cored wire without pre-heating. Process stability was monitored under a wide range of welding parameters. It was found that the technique can be used successfully to weld thick sections with appropriate quality when the parameters are optimized. When comparing conventional pulsed and the more advanced cold metal transfer pulse (CMT+P) arc modes, it was found that both can provide high quality welds. CMT+P arc mode can provide more stable droplet transfer over a limited range of travel speeds. At higher travel speeds, an unstable metal transfer mechanism was observed. Comparing leading arc and trailing arc arrangements, the leading arc configuration can provide higher quality welds and more stable processing at longer inter-distances between the heat sources.

  2. Exact vibration analysis of variable thickness thick annular isotropic and FGM plates

    Science.gov (United States)

    Efraim, E.; Eisenberger, M.

    2007-02-01

    Annular plates are used in many engineering structures. In many cases variable thickness is used in order to save weight and improve structural characteristics. In recent years functionally graded materials (FGM) are used in many engineering applications. A FGM plate is an inhomogeneous composite made of two constituents (usually ceramic and metal), with both the composition and the material properties varying smoothly through the thickness of the plate. An optimal distribution of material properties may be obtained. The plate vibrations will have a strong bending-stretching coupling effect. The equations of motion including the effect of shear deformations using the first-order shear deformation theory are derived and solved exactly for various combinations of boundary conditions. The solution is obtained by using the exact element method. Exact vibration frequencies and modes are given for several examples for the first time.

  3. Substrate morphology repetition in 'thick' polymer films

    International Nuclear Information System (INIS)

    Pietsch, Ullrich; Panzner, Tobias; Pfeiffer, Franz; Robinson, Ian K.

    2005-01-01

    Using Grazing-incidence small-angle scattering (GISAXS) technique we investigated the surface morphology of polymer films spin-coated on different silicon substrates. As substrates we used either technologically smooth silicon wafers or the same silicon wafer coated with thin aluminium or gold films which show a granular structure at the surface. Although the polymer thickness exceeds 300nm the GISAXS pattern of the film shows the same in-plane angle distribution Δ2Θ as the underlying substrate. Annealing the polymer films at a temperature above its glass transition temperature Δ2Θ changed from a broad to a narrow distribution as it is typically for films on pure silicon. The experiment can be interpreted by roughness replication and density fluctuation within the polymer film created while spin-coating at room temperature. Due to the low segment mobility there are density fluctuations which repeat the surface morphology of the substrate. Above the glass temperature the polymer density can be homogenized independently from the morphology of the substrate

  4. Axisymmetric vibrations of thick shells of revolution

    International Nuclear Information System (INIS)

    Suzuki, Katsuyoshi; Kosawada, Tadashi; Takahashi, Shin

    1983-01-01

    Axisymmetric shells of revolution are used for chemical plants, nuclear power plants, aircrafts, structures and so on, and the elucidation of their free vibration is important for the design. In this study, the axisymmetric vibration of a barrel-shaped shell was analyzed by the modified thick shell theory. The Lagrangian during one period of the vibration of a shell of revolution was determined, and from its stopping condition, the vibration equations and the boundary conditions were derived. The vibration equations were analyzed strictly by using the series solution. Moreover, the basic equations for the strain of a shell and others were based on those of Love. As the examples of numerical calculation, the natural frequency and vibration mode of the symmetrical shells of revolution fixed at both ends and supported at both ends were determined, and their characteristics were clarified. By comparing the results of this study with the results by thin shell theory, the effects of shearing deformation and rotary inertia on the natural frequency and vibration mode were clarified. The theoretical analysis and the numerical calculation are described. The effects of shearing deformation and rotary inertia on the natural frequency became larger in the higher order vibration. The vibration mode did not much change in both theories. (Kako, I.)

  5. Cladding Attachment Over Thick Exterior Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P. [Building Science Corporation, Somerville, MA (United States); Eng, P. [Building Science Corporation, Somerville, MA (United States); Lepage, R. [Building Science Corporation, Somerville, MA (United States)

    2014-01-01

    The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1.What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2.Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3.What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

  6. Cladding Attachment Over Thick Exterior Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P. [Building Science Corporation, Somerville, MA (United States); Eng, P. [Building Science Corporation, Somerville, MA (United States); Lepage, R. [Building Science Corporation, Somerville, MA (United States)

    2014-01-01

    The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1. What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2. Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3. What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

  7. Buckling Optimization of Thick Stiffened Cylindrical Shell

    Directory of Open Access Journals (Sweden)

    Qasim Hassan Bader

    2016-03-01

    Full Text Available In this work the critical pressure due to buckling was calculated numerically by using ANSYS15 for both stiffened and un-stiffened cylinder for various locations and installing types , strengthening of the cylinder causes a more significant increase in buckling pressures than non reinforced cylinder . The optimum design of structure was done by using the ASYS15 program; in this step the number of design variables 21 DVs. These variables are Independent variables that directly affect. The design variables represented the thickness of the cylinder and( height and width of 10 stiffeners. State variables (SVs, these variables are dependent variables that change as a result of changing the DVs and are necessary to constrain the design. The objective function is the one variable in the optimization that needs to be minimized. In this case the state variable is critical pressure (CP and the objective function is the total (volume of the structure. The optimum weight of the structure with reasonable required conditions for multi types of structure was found. The result shows the best location of stiffener at internal side with circumferential direction. In this case the critical pressure can be increased about 18.6% and the total weight of the structure decreases to 15.8%.

  8. Extended methods using thick-targets for nuclear reaction data of radioactive isotopes

    Science.gov (United States)

    Ebata, Shuichiro; Aikawa, Masayuki; Imai, Shotaro

    2017-09-01

    The nuclear transmutation is a technology to dispose of radioactive wastes. However, we do not have enough basic data for its developments, such as thick-target yields (TTY) and the interaction cross sections for radioactive material. We suggest two methods to estimate the TTY using inverse kinematics and to obtain the excitation function of the interaction cross sections which is named the thick-target transmission (T3) method. We deduce the energy-dependent conversion relation between the TTYs of the original system and its inverse kinematics, which can be replaced to a constant coefficient in the high energy region. Furthermore we show the usefulness of the T3 method to investigate the excitation function of the 12C + 27Al reaction in the simulation.

  9. Fracture resistance of monolithic zirconia molar crowns with reduced thickness.

    Science.gov (United States)

    Nakamura, Keisuke; Harada, Akio; Inagaki, Ryoichi; Kanno, Taro; Niwano, Yoshimi; Milleding, Percy; Örtengren, Ulf

    2015-01-01

    The purpose of the present study was to analyze the relationship between fracture load of monolithic zirconia crowns and axial/occlusal thickness and to evaluate the fracture resistance of monolithic zirconia crowns with reduced thickness in comparison with that of monolithic lithium disilicate crowns with regular thickness. Monolithic zirconia crowns (Lava Plus Zirconia, 3M/ESPE) with specified axial/occlusal thicknesses and lithium disilicate crowns (IPS e.max press, Ivoclar/Vivadent) with regular thickness were fabricated using a dental CAD/CAM system and a press technique, respectively. The crowns cemented onto dies were loaded until fracture. Based on measurements of the crown thickness made by micro-CT and the fracture load, multiple regression analysis was performed. It was revealed that the occlusal thickness significantly affected the fracture load (p zirconia crowns, the fracture load of the zirconia crowns with the occlusal thickness of 0.5 mm (5558 ± 522 N) was significantly higher than that of lithium disilicate crowns with an occlusal thickness of 1.5 mm (3147 ± 409 N). Within the limitations of the present study, it is suggested that monolithic zirconia crown with chamfer width of 0.5 mm and occlusal thickness of 0.5 mm can be used in the molar region in terms of fracture resistance.

  10. Loess Thickness Variations Across the Loess Plateau of China

    Science.gov (United States)

    Zhu, Yuanjun; Jia, Xiaoxu; Shao, Mingan

    2018-01-01

    The soil thickness is very important for investigating and modeling soil-water processes, especially on the Loess Plateau of China with its deep loess deposit and limited water resources. A digital elevation map (DEM) of the Loess Plateau and neighborhood analysis in ArcGIS software were used to generate a map of loess thickness, which was then validated by 162 observations across the plateau. The generated loess thickness map has a high resolution of 100 m × 100 m. The map indicates that loess is thick in the central part of the plateau and becomes gradually shallower in the southeast and northwest directions. The areas near mountains and river basins have the shallowest loess deposit. The mean loess thickness is the deepest in the zones with 400-600-mm precipitation and decreases gradually as precipitation varies beyond this range. Our validation indicates that the map just slightly overestimates loess thickness and is reliable. The loess thickness is mostly between 0 and 350 m in the Loess Plateau region. The calculated mean loess thickness is 105.7 m, with the calibrated value being 92.2 m over the plateau exclusive of the mountain areas. Our findings provide very basic data of loess thickness and demonstrate great progress in mapping the loess thickness distribution for the plateau, which are valuable for a better study of soil-water processes and for more accurate estimations of soil water, carbon, and solute reservoirs in the Loess Plateau of China.

  11. Smoluchowski coagulation models of sea ice thickness distribution dynamics

    Science.gov (United States)

    Godlovitch, D.; Illner, R.; Monahan, A.

    2011-12-01

    Sea ice thickness distributions display a ubiquitous exponential decrease with thickness. This tail characterizes the range of ice thickness produced by mechanical redistribution of ice through the process of ridging, rafting, and shearing. We investigate how well the thickness distribution can be simulated by representing mechanical redistribution as a generalized stacking process. Such processes are naturally described by a well-studied class of models known as Smoluchowski Coagulation Models (SCMs), which describe the dynamics of a population of fixed-mass "particles" which combine in pairs to form a "particle" with the combined mass of the constituent pair at a rate which depends on the mass of the interacting particles. Like observed sea ice thickness distributions, the mass distribution of the populations generated by SCMs has an exponential or quasi-exponential form. We use SCMs to model sea ice, identifying mass-increasing particle combinations with thickness-increasing ice redistribution processes. Our model couples an SCM component with a thermodynamic component and generates qualitatively accurate thickness distributions with a variety of rate kernels. Our results suggest that the exponential tail of the sea ice thickness distribution arises from the nature of the ridging process, rather than specific physical properties of sea ice or the spatial arrangement of floes, and that the relative strengths of the dynamic and thermodynamic processes are key in accurately simulating the rate at which the sea ice thickness tail drops off with thickness.

  12. Birth after cesarean section

    OpenAIRE

    Velem?nsk?, Milo?; Velem?nsk?, Milo?; Piskorzov?, Martina; Ba?kov?, Martina; T?thov?, Val?rie; Str?nsk?, Pravoslav

    2011-01-01

    Summary Background The number of incoming expectant women who have previously experienced cesarean section has increased. This work sought to find the frequency and connections between vaginal deliveries, cesarean sections, and iterative cesarean sections from 2004 to 2008. Material/Methods In all, 828 women with previous cesarean sections were included. From this group, 8282 vaginal deliveries were performed. During these years, 828 women had a history of the cesarean section; in these women...

  13. Leukoaraiosis is associated with arterial wall thickness: a quantitative analysis.

    Science.gov (United States)

    Auriel, Eitan; Csiba, Laszlo; Berenyi, Ervin; Varkonyi, Ildiko; Mehes, Gabor; Kardos, Laszlo; Karni, Arnon; Bornstein, Natan M

    2012-06-01

    Leukoaraiosis refers to an age-related, abnormal appearance of the brain white matter on neuroimaging. The association between leukoaraiosis and cerebrovascular disease suggests that ischemia may be an important contributing factor; however, the pathogenesis of the condition remains controversial. We hypothesized that physical abnormalities of blood vessels might be culpable and compared the external and internal measurements of blood vessel walls between brains that demonstrated leukoaraiosis on imaging and normal control brains. Fourteen brains of individuals who had been diagnosed as having severe leukoaraiosis and five non-leukoaraiosis control brains were studied. Arterial cross-sections were evaluated by length measurements with an image analysis device. Arterial wall thickness and the ratio of the outer and inner diameters of the vessel were measured. We measured a total of 108 vessels in the leukoaraiosis group and 95 vessels in the control group. The vessel walls of the leukoaraiosis patients were an average of 5.5 µm thicker than the walls of control vessels of the same inside diameter (P = 0.0000, 95% CI 3.01-8.08) and an average of 2.3 µm thicker than walls of control vessels of the same outside diameter (P = 0.016, 95% CI 0.48-4.17). Our data provide evidence that leukoaraiosis is associated with vessel wall thickening in an additive fashion and indicate that structural vascular abnormalities are associated with leukoaraiosis. © 2011 Japanese Society of Neuropathology.

  14. Multiple High Voltage Pulse Stressing of Polymer Thick Film Resistors

    Directory of Open Access Journals (Sweden)

    Busi Rambabu

    2014-01-01

    Full Text Available The purpose of this paper is to study high voltage interactions in polymer thick film resistors, namely, polyvinyl chloride- (PVC- graphite thick film resistors, and their applications in universal trimming of these resistors. High voltages in the form of impulses for various pulse durations and with different amplitudes have been applied to polymer thick film resistors and we observed the variation of resistance of these resistors with high voltages. It has been found that the resistance of polymer thick film resistors decreases in the case of higher resistivity materials and the resistance of polymer thick film resistor increases in the case of lower resistivity materials when high voltage impulses are applied to them. It has been also found that multiple high voltage pulse (MHVP stressing can be used to trim the polymer thick film resistors either upwards or downwards.

  15. Kinetics of the crust thickness development of bread during baking.

    Science.gov (United States)

    Soleimani Pour-Damanab, Alireza; Jafary, A; Rafiee, Sh

    2014-11-01

    The development of crust thickness of bread during baking is an important aspect of bread quality and shelf-life. Computer vision system was used for measuring the crust thickness via colorimetric properties of bread surface during baking process. Crust thickness had a negative and positive relationship with Lightness (L (*) ) and total color change (E (*) ) of bread surface, respectively. A linear negative trend was found between crust thickness and moisture ratio of bread samples. A simple mathematical model was proposed to predict the development of crust thickness of bread during baking, where the crust thickness was depended on moisture ratio that was described by the Page moisture losing model. The independent variables of the model were baking conditions, i.e. oven temperature and air velocity, and baking time. Consequently, the proposed model had well prediction ability, as the mean absolute estimation error of the model was 7.93 %.

  16. Fracture resistance of monolithic zirconia molar crowns with reduced thickness

    OpenAIRE

    Nakamura, Keisuke; Harada, A.; Inagaki, R.; Kanno, Taro; Niwano, Y.; Milleding, Percy; Ørtengren, Ulf Thore

    2015-01-01

    This is the accepted manuscript version. Published version is available at Acta Odontologica Scandinavica Objectives. The purpose of the present study was to analyze the relationship between fracture load of monolithic zirconia crowns and axial/occlusal thickness, and to evaluate the fracture resistance of monolithic zirconia crowns with reduced thickness in comparison with that of monolithic lithium disilicate crowns with regular thickness. Materials and methods. Monolithic zi...

  17. Surface states in thin versus thick organic quantum wells

    International Nuclear Information System (INIS)

    Nguyen Ba An; Hanamura, E.

    1995-08-01

    Surface states are studied in dependence on thickness or organic quantum wells within the nearest layer approximation. It is shown that there is a material-dependent critical thickness. Structures, that have thickness thinner or thicker than the critical one, exhibit qualitatively different characteristics of surface states. Criteria for existence and sign rules for location of energy levels of surface states are established which are general and contain the results of the previous works as particular cases. (author). 18 refs, 3 figs

  18. Trochanteric Soft Tissue Thickness and Hip Fracture in Older Men

    Science.gov (United States)

    Nielson, Carrie M.; Bouxsein, Mary L.; Freitas, Sinara S.; Ensrud, Kristine E.; Orwoll, Eric S.

    2009-01-01

    Background: Greater thickness of the tissue extending laterally from the greater trochanter has been associated with a lower risk of hip fracture in women. The effect of trochanteric soft tissue thickness on the risk of incident hip fracture has not been evaluated in men. Methods: We measured trochanteric soft tissue thickness by dual-energy x-ray absorptiometry for all incident hip fracture cases (n = 70) and 222 randomly selected noncases in older men (≥65 yr) enrolled in the Osteoporotic Fractures in Men (MrOS) Study. Differences in tissue thickness between cases and controls were examined. Changes in fall force and factor-of-risk (the ratio of force from a sideways fall to femoral bone strength) associated with tissue thickness were determined. The relative risk for incident hip fracture per sd decrease in tissue thickness was calculated. Results: Mean trochanteric soft tissue thickness did not differ significantly between cases and noncases (29.1 ± 11.9 vs 31.0 ± 11.5 mm; P = 0.2). Although increased tissue thickness reduced both the estimates of fall force and the factor-of-risk, tissue thickness was not associated with the risk of hip fracture (age- and bone mineral density-adjusted relative risk per sd decrease in tissue thickness = 0.90; 95% confidence interval, 0.70–1.16). Conclusions: In this study of elderly community-dwelling men, we found no significant association between trochanteric soft tissue thickness and incident hip fracture. Trochanteric soft tissue thickness in these men was less than previously reported in older women and may explain the difference between these results and those reported in women. PMID:19017753

  19. A variable thickness window: Thermal and structural analyses

    International Nuclear Information System (INIS)

    Wang, Zhibi; Kuzay, T.M.

    1994-01-01

    In this paper, the finite difference formulations for variable thickness thermal analysis and variable thickness plane stress analysis are presented. In heat transfer analysis, radiation effects and temperature-dependent thermal conductivity are taken into account. While in thermal stress analysis, the thermal expansion coefficient is considered as temperature dependent. An application of the variable thickness window to an Advanced Photon Source beamline is presented

  20. Femoral cartilage thickness measurements in healthy individuals: learning, practicing and publishing with TURK-MUSCULUS.

    Science.gov (United States)

    Özçakar, Levent; Tunç, Hakan; Öken, Öznur; Ünlü, Zeliha; Durmuş, Bekir; Baysal, Özlem; Altay, Zuhal; Tok, Fatih; Akkaya, Nuray; Doğu, Beril; Çapkın, Erhan; Bardak, Ayşenur; Çarlı, Alparslan Bayram; Buğdaycı, Derya; Toktaş, Hasan; Dıraçoğlu, Demirhan; Gündüz, Berrin; Erhan, Belgin; Kocabaş, Hilal; Erden, Gül; Günendi, Zafer; Kesikburun, Serdar; Omaç, Özlem Köroğlu; Taşkaynatan, Mehmet Ali; Şenel, Kazım; Uğur, Mahir; Yalçınkaya, Ebru Yılmaz; Öneş, Kadriye; Atan, Çiğdem; Akgün, Kenan; Bilgici, Ayhan; Kuru, Ömer; Özgöçmen, Salih

    2014-01-01

    Measurement of the femoral cartilage thickness by using in-vivo musculoskeletal ultrasonography (MSUS) has been previously shown to be a valid and reliable method in previous studies; however, to our best notice, normative data has not been provided before in the healthy population.The aim of our study was to provide normative data regarding femoral cartilage thicknesses of healthy individuals with collaborative use of MSUS. This is across-sectional study run at Physical and Rehabilitation Medicine Departments of 18 Secondary and Tertiary Centers in Turkey. 1544 healthy volunteers (aged between 25-40 years) were recruited within the collaboration of TURK-MUSCULUS (Turkish Musculoskeletal Ultrasonography Study Group). Subjects who had a body mass index value of less than 30 and who did not have signs and symptoms of any degenerative/inflammatory arthritis or other rheumatic diseases, history of knee trauma and previous knee surgery were enrolled. Ultrasonographic measurements were performed axially from the suprapatellar window by using linear probes while subjects' knees were in maximum flexion. Three (mid-point) measurements were taken from both knees (lateral condyle, intercondylar area, medial condyle). A total of 2876 knees (of 817 M, 621 F subjects) were taken into analysis after exclusion of inappropriate images. Mean cartilage thicknesses were significantly lower in females than males (all p< 0.001). Thickness values negatively correlated with age; negatively (females) and positively (males) correlated with smoking. Men who regularly exercised had thicker cartilage than who did not exercise (all p < 0.05). Increased age (in both sexes) and absence of exercise (males) were found to be risk factors for decreased cartilage thicknesses. Further data pertaining to other countries would be interesting to uncover whether ethnic differences also affect cartilage thickness. Collaborative use of MSUS seems to be promising in this regard.

  1. Cortical thickness in a case of congenital unilateral perisylvian syndrome.

    Science.gov (United States)

    Kotini, A; Camposano, S; Hara, K; Salat, D; Cole, A; Stufflebeam, S; Halgren, E

    2004-11-30

    In congenital perisylvian syndrome, there is polymicrogyric cortex distributed in variable extensions around the sylvian fissure. Unilateral cases usually present with congenital hemiparesis, while bilateral cases have pseudobulbar paralysis of the oropharingoglossal region. Both unilateral and bilateral cases have a high rate of epilepsy. Polymicrogyric cortex is characterized by too many small convolutions. Often there are no intervening sulci, and almost no white matter can be seen under them. On MRI they appear to have increased thickness. Bilateral and symmetric polimycrogiria can be hard to recognize on standard MRIs. Accurate and automated methods for measuring the thickness of cerebral cortex are available. They have mainly been used to study a variety of disorders with diminished cortical thickness. We studied a case of right perisylvian polymicrogyria, who presented in adult life with epilepsy and had a normal neurological exam. Fischl and Dale's automated cortical thickness analysis rendered a very clear picture of increased cortical thickness with values up to 9 mm in the affected areas (normal cortical thickness varies between 1 and 4.5 mm). The thickest areas were seen over grossly abnormal gyri on the reconstructed cerebral cortex. On MEG he presented a prominent and monotonous 9 Hz activity that was located within the limits of a thick gyrus. There was a significant difference of thickness between homologous hemispheric areas. To our surprise some areas of the left hemisphere also appeared to have increased thickness, raising the question of a bilateral asymmetric case.

  2. A study of compressed breast thickness at Hirosaki University Hospital

    International Nuclear Information System (INIS)

    Kon, Masanori; Osanai, Tsunemi; Ootani, Yuhiko; Sugawara, Kaoru; Abe, Katsumi

    2000-01-01

    Evaluation of image quality and medical exposure dose is very important in mammography. However, the standard compressed breast thickness of Japanese women is uncertain. Authors therefore analyzed compressed breast thickness on bilateral cephalocaudal and mediolateral oblique radiographs of 3445 women who underwent mammography between June 5, 1989 and December 7, 1998. The total average compressed breast thickness was about 10 mm less than the thickness of the American College of Radiography (ACR) standard mammographic accreditation phantom. It therefore appears necessary to establish a Japanese standard for the phantom to evaluate image quality and medical exposure dose accurately in Japanese women. (K.H.)

  3. Thickness measurement by using cepstrum ultrasonic signal processing

    International Nuclear Information System (INIS)

    Choi, Young Chul; Yoon, Chan Hoon; Choi, Heui Joo; Park, Jong Sun

    2014-01-01

    Ultrasonic thickness measurement is a non-destructive method to measure the local thickness of a solid element, based on the time taken for an ultrasound wave to return to the surface. When an element is very thin, it is difficult to measure thickness with the conventional ultrasonic thickness method. This is because the method measures the time delay by using the peak of a pulse, and the pulses overlap. To solve this problem, we propose a method for measuring thickness by using the power cepstrum and the minimum variance cepstrum. Because the cepstrums processing can divides the ultrasound into an impulse train and transfer function, where the period of the impulse train is the traversal time, the thickness can be measured exactly. To verify the proposed method, we performed experiments with steel and, acrylic plates of variable thickness. The conventional method is not able to estimate the thickness, because of the overlapping pulses. However, the cepstrum ultrasonic signal processing that divides a pulse into an impulse and a transfer function can measure the thickness exactly.

  4. Stratospheric thickness determined directly from satellite radiance measurements.

    Science.gov (United States)

    Quiroz, R. S.; Gelman, M. E.

    1972-01-01

    Discussion of the use of satellite radiance data for determining the thickness of deep stratospheric layers. Empirical regression equations are shown to provide better estimates of stratospheric thickness than do mean weighted temperatures obtained from the Planck equation. The best regression equations were found for thick layers emitting a substantial portion of the CO2-band infrared radiation measured by satellites. By adding the layer thickness to the observed height field for the lower boundary, it is possible to construct constant-pressure maps at very high altitudes.

  5. Cortical thickness abnormalities in late adolescence with online gaming addiction.

    Science.gov (United States)

    Yuan, Kai; Cheng, Ping; Dong, Tao; Bi, Yanzhi; Xing, Lihong; Yu, Dahua; Zhao, Limei; Dong, Minghao; von Deneen, Karen M; Liu, Yijun; Qin, Wei; Tian, Jie

    2013-01-01

    Online gaming addiction, as the most popular subtype of Internet addiction, had gained more and more attention from the whole world. However, the structural differences in cortical thickness of the brain between adolescents with online gaming addiction and healthy controls are not well unknown; neither was its association with the impaired cognitive control ability. High-resolution magnetic resonance imaging scans from late adolescence with online gaming addiction (n = 18) and age-, education- and gender-matched controls (n = 18) were acquired. The cortical thickness measurement method was employed to investigate alterations of cortical thickness in individuals with online gaming addiction. The color-word Stroop task was employed to investigate the functional implications of the cortical thickness abnormalities. Imaging data revealed increased cortical thickness in the left precentral cortex, precuneus, middle frontal cortex, inferior temporal and middle temporal cortices in late adolescence with online gaming addiction; meanwhile, the cortical thicknesses of the left lateral orbitofrontal cortex (OFC), insula, lingual gyrus, the right postcentral gyrus, entorhinal cortex and inferior parietal cortex were decreased. Correlation analysis demonstrated that the cortical thicknesses of the left precentral cortex, precuneus and lingual gyrus correlated with duration of online gaming addiction and the cortical thickness of the OFC correlated with the impaired task performance during the color-word Stroop task in adolescents with online gaming addiction. The findings in the current study suggested that the cortical thickness abnormalities of these regions may be implicated in the underlying pathophysiology of online gaming addiction.

  6. Cortical thickness abnormalities in late adolescence with online gaming addiction.

    Directory of Open Access Journals (Sweden)

    Kai Yuan

    Full Text Available Online gaming addiction, as the most popular subtype of Internet addiction, had gained more and more attention from the whole world. However, the structural differences in cortical thickness of the brain between adolescents with online gaming addiction and healthy controls are not well unknown; neither was its association with the impaired cognitive control ability. High-resolution magnetic resonance imaging scans from late adolescence with online gaming addiction (n = 18 and age-, education- and gender-matched controls (n = 18 were acquired. The cortical thickness measurement method was employed to investigate alterations of cortical thickness in individuals with online gaming addiction. The color-word Stroop task was employed to investigate the functional implications of the cortical thickness abnormalities. Imaging data revealed increased cortical thickness in the left precentral cortex, precuneus, middle frontal cortex, inferior temporal and middle temporal cortices in late adolescence with online gaming addiction; meanwhile, the cortical thicknesses of the left lateral orbitofrontal cortex (OFC, insula, lingual gyrus, the right postcentral gyrus, entorhinal cortex and inferior parietal cortex were decreased. Correlation analysis demonstrated that the cortical thicknesses of the left precentral cortex, precuneus and lingual gyrus correlated with duration of online gaming addiction and the cortical thickness of the OFC correlated with the impaired task performance during the color-word Stroop task in adolescents with online gaming addiction. The findings in the current study suggested that the cortical thickness abnormalities of these regions may be implicated in the underlying pathophysiology of online gaming addiction.

  7. The Effect of Nozzle Trailing Edge Thickness on Jet Noise

    Science.gov (United States)

    Henderson, Brenda; Kinzie, Kevin; Haskin, Henry

    2004-01-01

    The effect of nozzle trailing edge thickness on broadband acoustic radiation and the production of tones is investigated for coannular nozzles. Experiments were performed for a core nozzle trailing edge thickness between 0.38 mm and 3.17 mm. The on-set of discrete tones was found to be predominantly affected by the velocity ratio, the ratio of the fan velocity to the core velocity, although some dependency on trailing edge thickness was also noted. For a core nozzle trailing edge thickness greater than or equal to 0.89 mm, tones were produced for velocity ratios between 0.91 and 1.61. For a constant nozzle trailing edge thickness, the frequency varied almost linearly with the core velocity. The Strouhal number based on the core velocity changed with nozzle trailing edge thickness and varied between 0.16 and 0.2 for the core nozzles used in the experiments. Increases in broadband noise with increasing trailing edge thickness were observed for tone producing and non-tone producing conditions. A variable thickness trailing edge (crenellated) nozzle resulted in no tonal production and a reduction of the broadband trailing edge noise relative to that of the corresponding constant thickness trailing edge.

  8. Thin-section CT of Cushing's disease

    International Nuclear Information System (INIS)

    Takahashi, Tatsuo; Kuwayama, Akio; Katoh, Tetsuo; Ichihara, Kaoru; Kageyama, Naoki; Nakamura, Koji.

    1983-01-01

    Using 1.5 mm contiguous sections with a GE CT/T 8800 scanner, we investigated the sellar regions of 22 cases of Cushing's diseases which had been diagnosed endocrinologically. Each sellar turcica was normal in size, and in only 5 cases were there significant findings on 2 mm-thick sellar-floor polytomography. Nine tumors appeared as regions of a hypodense area, and three tumors were diagnosed by indirect signs, for example, stalk deviation and diaphragmatic plane asymmetry. The other 10 cases, especially those previously operated on or irradiated, were diagnosed as falsely positive or negative. Because it is best of the microadenomas appear hypodense within the strongly contrast-enhanced anterior pituitary glands, it is better for scans to be obtained immediately after rapid intravenous contrast infusion. Hypodense areas of microadenomas are best demonstrated on direct coronal scans or reversed scans of 1.5 mm-thickness thin-slice sections. By these methods, microadenomas, if they are over 5-6 mm in diameter, can appear as hypodense. Sellar floor findings by means of thin-section CT were more sensitive than those of polytomography and had more advantages in local diagnosis. If the tumor were over 4 mm in diameter, local changes in the sellar floor could be demonstrated by thin-section CT, but by polytomography no changes in the sellar floor could be demonstrated until the tumor size reached 6 mm. (author)

  9. Cesarean Section - Multiple Languages

    Science.gov (United States)

    ... Are Here: Home → Multiple Languages → All Health Topics → Cesarean Section URL of this page: https://medlineplus.gov/languages/ ... V W XYZ List of All Topics All Cesarean Section - Multiple Languages To use the sharing features on ...

  10. FEMA DFIRM Cross Sections

    Data.gov (United States)

    Minnesota Department of Natural Resources — FEMA Cross Sections are required for any Digital Flood Insurance Rate Map database where cross sections are shown on the Flood Insurance Rate Map (FIRM). Normally...

  11. Thickness-Dependent Bioelectrochemical and Energy Applications of Thickness-Controlled Meso-Macroporous Antimony-Doped Tin Oxide

    Directory of Open Access Journals (Sweden)

    Daniel Mieritz

    2018-04-01

    Full Text Available Coatings of hierarchically meso-macroporous antimony-doped tin oxide (ATO enable interfacing adsorbed species, such as biomacromolecules, with an electronic circuit. The coating thickness is a limiting factor for the surface coverage of adsorbates, that are electrochemically addressable. To overcome this challenge, a carbon black-based templating method was developed by studying the composition of the template system, and finding the right conditions for self-standing templates, preventing the reaction mixture from flowing out of the mask. The thicknesses of as-fabricated coatings were measured using stylus profilometry to establish a relationship between the mask thickness and the coating thickness. Cyclic voltammetry was performed on coatings with adsorbed cytochrome c to check whether the entire coating thickness was electrochemically addressable. Further, bacterial photosynthetic reaction centers were incorporated into the coatings, and photocurrent with respect to coating thickness was studied. The template mixture required enough of both carbon black and polymer, roughly 7% carbon black and 6% poly(ethylene glycol. Coatings were fabricated with thicknesses approaching 30 µm, and thickness was shown to be controllable up to at least 15 µm. Under the experimental conditions, photocurrent was found to increase linearly with the coating thickness, up to around 12 µm, above which were diminished gains.

  12. Effect of slice thickness on detectability in breast CT using a prewhitened matched filter and simulated mass lesions

    Science.gov (United States)

    Packard, Nathan J.; Abbey, Craig K.; Yang, Kai; Boone, John M.

    2012-01-01

    Purpose: Dedicated breast CT (bCT) is an emerging technology with the potential to improve the detection of breast cancer in screening and diagnostic capacities. Typically, the 3D volume reconstructed from the scanner is displayed as sectional images. The purpose of this study was to evaluate the effect of section thickness on the detectability of simulated masses using a prewhitened matched filter (PWMF) as a model observer. Methods: A breast CT scanner has been designed and fabricated in the authors’ laboratory with more than 200 women imaged in IRB-approved phase I and phase II trials to date. Of these, 151 bilateral data sets were selected on the basis of low artifact content, sufficient breast coverage, and excluding cases with breast implants. BIRADS breast density ratings were available for 144 of these patients. Spherical mass lesions of diameter 1, 2, 3, 5, 11, and 15 mm were mathematically generated and embedded at random locations within the parenchymal region of each bCT volume. Microcalcifications were not simulated in this study. For each viewing plane (sagittal, axial, and coronal) and section thickness (ranging from 0.3 to 44 mm), section images of the breast parenchyma containing the lesion were generated from the reconstructed bCT data sets by averaging voxels over the length of the section. Using signal known exactly (SKE) model observer methodology, receiver operating characteristic (ROC) curve analysis was performed on each generated projected image using a PWMF based model observer. ROC curves were generated for each breast data set, and the area under the ROC curve (AUC) was evaluated as well as the sensitivity at 95% specificity. Results: For all lesion sizes, performance rises modestly to a peak before falling off substantially as section thickness increases over the range of the study. We find that the optimal section thickness tracks the size of the lesion to be detected linearly with a small positive offset and slopes ranging from 0

  13. Relationship between leukoaraiosis, carotid intima-media thickness and intima-media thickness variability: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Lucatelli, Pierleone [University of Rome la Sapienza, Department of Radiology, Rome (Italy); Raz, Eytan [New York University Langone Medical Center, Department of Radiology, New York, NY (United States); Saba, Luca [Azienda Ospedaliero Universitaria, Department of Radiology, di Cagliari - Polo di Monserrato, Cagliari (Italy); Argiolas, Giovanni Maria; Siotto, Paolo [Azienda Ospedaliera Brotzu, Department of Radiology, Cagliari (Italy); Montisci, Roberto [Azienda Ospedaliero Universitaria, Department of Vascular Surgery, di Cagliari - Polo di Monserrato, Cagliari (Italy); Wintermark, Max [University of Virginia, Department of Radiology, Neuroradiology Division, 1215 Lee Street-New Hospital, PO Box 800170, Charlottesville, VA (United States); King, Kevin S. [University of Texas Southwestern Medical Center, Department of Radiology, Dallas, TX (United States); Molinari, Filippo [Politecnico di Torino, Biolab, Department of Electronics, Torino (Italy); Ikeda, Nobutaka [Toho University Ohashi Medical Center, Division of Cardiovascular Medicine, Tokyo (Japan); Suri, Jasjit S. [AtheroPoint trademark LLC, Diagnostic and Monitoring Division, Roseville, CA (United States); University of Idaho, Department of Electrical Engineering, Pocatello, ID (United States)

    2016-12-15

    To assess the relationship between the degree of leukoaraiosis (LA), carotid intima-media thickness (IMT) and intima-media thickness variability (IMTV). Sixty-one consecutive patients, who underwent a brain MRI examination and a carotid artery ultrasound, were included in this retrospective study, which conformed with the Declaration of Helsinki. Written informed consent was waived. In each patient, right/left carotid arteries and brain hemispheres were assessed using automated software for IMT, IMTV and LA volume. The mean hemispheric LA volume was 2,224 mm{sup 3} (SD 2,702 mm{sup 3}) and there was no statistically significant difference in LA volume between the right and left hemispheres (p value = 0.628). The mean IMT and IMTV values were 0.866 mm (SD 0.170) and 0.143 mm (SD 0.100), respectively, without significant differences between the right and left sides (p values 0.733 and 0.098, respectively). The correlation coefficient between IMTV and LA volume was 0.41 (p value = 0.0001), and 0.246 (p value = 0.074) between IMT and LA volume. IMTV significantly correlates with LA volume. Further studies are warranted to verify whether this parameter can be used clinically as a marker of cerebrovascular risk. (orig.)

  14. Normal reference range of fetal nuchal translucency thickness in pregnant women in the first trimester, one center study

    Directory of Open Access Journals (Sweden)

    Marzeie Sharifzadeh

    2015-01-01

    Full Text Available Background: Considering that establishment of reference value of nuchal translucency (NT-related to the crown rump length (CRL during the first trimester will be helpful for determining an appropriate cutoff level for screening of increased NT thickness-related abnormalities, we determined the NT thickness and investigated its relation with different chromosomal and nonchromosomal abnormalities among a large sample size of pregnant Iranian women. Materials and Methods: In this analytic cross-sectional study, pregnant women who were in their first trimester were enrolled at their antenatal visit. Using an abdominal ultrasonography, the fetal NT thickness of the studied population was measured. Those with increased NT thickness were determined. The reference value of NT thickness (5th, 25th, 50th, 75th, and 95th percentiles within each 5-mm range of CRL and during the 11th, 12th, and 13th gestational weeks were determined. The presences of the different chromosomal and nonchromosomal abnormalities were compared in women with different percentiles of NT thickness who underwent amniocentesis and those who did not. Results: 1,614 pregnant women were evaluated. The mean NT thickness was 1.30 ± 0.54 mm. Increased NT thickness >2 mm and >95th percentile according to their gestational age (GA was detected in 89 (5.5% and 58 (3.6% pregnant women. The reference 95th percentile value range for NT was 1.8-2.35 and increased NT thickness according to our obtained values was associated significantly with chromosomal abnormalities. Conclusion: The obtained reference range in our studied population was different from that reported for other ethnic groups and it is suggested that using this values are more favorable for screening of chromosomal abnormalities during the first trimester of pregnancy than the recommended single cutoff value.

  15. Normal reference range of fetal nuchal translucency thickness in pregnant women in the first trimester, one center study

    Science.gov (United States)

    Sharifzadeh, Marzeie; Adibi, Atoosa; Kazemi, Kimia; Hovsepian, Silva

    2015-01-01

    Background: Considering that establishment of reference value of nuchal translucency (NT)-related to the crown rump length (CRL) during the first trimester will be helpful for determining an appropriate cutoff level for screening of increased NT thickness-related abnormalities, we determined the NT thickness and investigated its relation with different chromosomal and nonchromosomal abnormalities among a large sample size of pregnant Iranian women. Materials and Methods: In this analytic cross-sectional study, pregnant women who were in their first trimester were enrolled at their antenatal visit. Using an abdominal ultrasonography, the fetal NT thickness of the studied population was measured. Those with increased NT thickness were determined. The reference value of NT thickness (5th, 25th, 50th, 75th, and 95th percentiles) within each 5-mm range of CRL and during the 11th, 12th, and 13th gestational weeks were determined. The presences of the different chromosomal and nonchromosomal abnormalities were compared in women with different percentiles of NT thickness who underwent amniocentesis and those who did not. Results: 1,614 pregnant women were evaluated. The mean NT thickness was 1.30 ± 0.54 mm. Increased NT thickness >2 mm and >95th percentile according to their gestational age (GA) was detected in 89 (5.5%) and 58 (3.6%) pregnant women. The reference 95th percentile value range for NT was 1.8-2.35 and increased NT thickness according to our obtained values was associated significantly with chromosomal abnormalities. Conclusion: The obtained reference range in our studied population was different from that reported for other ethnic groups and it is suggested that using this values are more favorable for screening of chromosomal abnormalities during the first trimester of pregnancy than the recommended single cutoff value. PMID:26929762

  16. Fires and Thick Smoke Across Southeast Asia

    Science.gov (United States)

    2007-01-01

    Vehicles and power plants are not the only sources of air pollution and greenhouses gases: fires contribute, too. In the Northern Hemisphere spring, which is the end of dry season across much of Southeast Asia, thousands of fires burn each year as people clear cropland and pasture in anticipation of the upcoming wet (growing) season. Intentional fires also escape people's control and burn into adjacent forest. The smoke from these fires crosses the Pacific Ocean, affecting climate far away. This dramatic photo-like image of fires and smoke in Southeast Asia was captured on April 2, 2007, by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite. MODIS detected hundreds, possibly thousands of fires (marked in red), burning in Thailand, Laos, Vietnam, and China. Thick smoke hides nearly all of Laos, where the highest concentration of fires is located. In southern China and northern Vietnam, the smoke has sunk into the valleys that crisscross the mountainous terrain; only the highest ridgelines, which appear dark green, emerge from the blanket of smoke. The smoke sails above a bank of clouds at upper right as a dingy, yellowish haze. Fires have been burning in the region for more than month, as shown by the high carbon monoxide levels observed by NASA's MOPITT sensor during March 2007. In addition to carbon dioxide and other greenhouse gases, fires produce tiny particles of incompletely burned, or charred, carbon. According to research published in mid-March 2007 in the Journal of Geophysical Research, significant amounts of this black carbon travel across the Pacific Ocean to North America at altitudes above 2 kilometers. In spring 2004, between 25-35 gigatons (roughly 55 to 77 million pounds) of black carbon crossed the Pacific and entered skies over western North America between March 26 and April 25; nearly 75 percent of it came from Asia. (Smoke and other pollution have no respect for borders; for example, scientists have also

  17. The effect of silver thickness on the enhancement of polymer based SERS substrates

    International Nuclear Information System (INIS)

    Schneidewind, H; Weber, K; Zeisberger, M; Hübner, U; Dellith, A; Cialla-May, D; Mattheis, R; Popp, J

    2014-01-01

    We investigated silver-covered polymer based nanogratings as substrates for surface-enhanced Raman spectroscopy (SERS), in particular with respect to the thickness of the plasmonically active silver film. In order to obtain accurate geometrical input data for the simulation process, we inspected cross sections of the gratings prepared by breaking at cryogenic temperature. We noticed a strong dependence of the simulation results on geometrical variations of the structures. Measurements revealed that an increasing silver film thickness on top of the nanogratings leads to a blue shift of the plasmonic resonance, as predicted by numerical simulations, as well as to an increased field enhancement for an excitation at 488 nm. We found a clear deviation of the experimental data compared to the simulated results for very thin silver films due to an island-like growth at a silver thickness below 20 nm. In order to investigate the SERS activity. we carried out measurements with crystal violet as a model analyte at an excitation wavelength of 488 nm. The SERS enhancement increases up to a silver thickness of about 30 nm, whereas it remains nearly constant for thicker silver films. (paper)

  18. Neutron diffraction measurements of residual stresses in a 50 mm thick weld

    International Nuclear Information System (INIS)

    Woo, Wanchuck; Em, Vyacheslav; Mikula, Pavel; An, Gyu-Baek; Seong, Baek-Seok

    2011-01-01

    Research highlights: → Determined residual stresses through the thickness of the 50 mm thick weld. → Two-dimensional mapping of the longitudinal stress. Observed significant stresses along the heat-affected zone. → Measured the maximum stress of 460 MPa at 40 mm below from the top surface. - Abstract: Residual stresses were determined through the thickness of a 50 mm thick ferrite steel weld plate using neutron diffraction. Whereas the limiting penetration depth for iron-based alloys is about 25 mm in the most typical neutron diffractometers, we significantly enhanced the penetration depth up to 50 mm with 2 mm spatial resolution by using the neutron wavelength of 2.39 A. The selected wavelength minimizes the total neutron cross-section and beam attenuation, thereby, maximizes the neutron fluxes at depth. Two-dimensional mapping of the residual stresses shows that significant amounts of the tensile longitudinal stresses (over 90% of yield strength) were developed along the heat-affected zone of the weld.

  19. Manipulating single second mode transparency in a corrugated waveguide via the thickness of sputtered gold

    International Nuclear Information System (INIS)

    Xu, Dan; Fan, Ya-Xian; Sang, Tang-Qing; Xu, Lan-Lan; Bibi, Aysha; Tao, Zhi-Yong

    2016-01-01

    We propose a classical analog of electromagnetically induced transparency in a cylindrical waveguide with undulated metallic walls. The transparency, induced by multi-mode interactions in waveguides, not only has a narrow line-width, but also consists of a single second-order transverse mode, which corresponds to the Bessel function distributions investigated extensively due to their unique characteristics. By increasing the thickness of sputtered gold layers of the waveguide, we demonstrate a frequency-agile single mode transparency phenomenon in a terahertz radiation. It is found that the center frequency of the transparency is linearly related to the gold thickness, indicating the achievement of a controllable single mode terahertz device. The field distributions at the cross-sections of outlets verify the single second mode transparency and indicate the mechanism of its frequency manipulation, which will significantly benefit the mode-control engineering in terahertz applications. - Highlights: • An analog of electromagnetically induced transparency in terahertz tubes is proposed. • A single second transverse mode of Bessel distributions is observed in the pass band. • The operating frequency can be linearly controlled by the sputtered gold thickness. • We can effectively manipulate the slow down factor of light by the gold thickness. • The transparency characteristics rely on the transition of multi-mode interactions.

  20. The effect of cigarette smoking on retinal nerve fiber layer thickness in patients with migraine.

    Science.gov (United States)

    Demirci, Seden; Gunes, Alime; Demirci, Serpil; Kutluhan, Suleyman; Tok, Levent; Tok, Ozlem

    2016-03-01

    Migraine is a frequent and disabling chronic neurological condition with complex pathophysiology. Both cigarette smoking and migraine may cause damage to the optic nerve. The primary objective of this study was to investigate the effect of cigarette smoking on retinal nerve fiber layer (RNFL) thickness in patients with migraine. Eighty-four consecutive patients diagnosed with migraine (34 smokers and 50 nonsmokers) and 66 age- and gender-matched healthy non-smoker controls were enrolled for this observational cross-sectional study. RNFL thickness was measured using spectral-domain optical coherence tomography (OCT) and then RNFL thickness in patients with migraine who smoke was compared to nonsmoking patients with migraine and healthy subjects. The average, superior, nasal and inferior RNFL thicknesses were significantly thinner in patients with migraine compared to the control group (p smoking may cause significant RNFL thinning in patients with migraine. OCT may be a feasible technique for determination of smoking-induced ocular damage in patients with migraine.

  1. Manipulating single second mode transparency in a corrugated waveguide via the thickness of sputtered gold

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Dan [Key Lab of In-fiber Integrated Optics, Ministry of Education of China, Harbin Engineering University, Harbin 150001 (China); Photonics Research Center, College of Science, Harbin Engineering University, Harbin 150001 (China); Fan, Ya-Xian, E-mail: yxfan@hrbeu.edu.cn [Key Lab of In-fiber Integrated Optics, Ministry of Education of China, Harbin Engineering University, Harbin 150001 (China); Photonics Research Center, College of Science, Harbin Engineering University, Harbin 150001 (China); Sang, Tang-Qing; Xu, Lan-Lan; Bibi, Aysha [Key Lab of In-fiber Integrated Optics, Ministry of Education of China, Harbin Engineering University, Harbin 150001 (China); Photonics Research Center, College of Science, Harbin Engineering University, Harbin 150001 (China); Tao, Zhi-Yong, E-mail: zytao@hrbeu.edu.cn [Key Lab of In-fiber Integrated Optics, Ministry of Education of China, Harbin Engineering University, Harbin 150001 (China); Photonics Research Center, College of Science, Harbin Engineering University, Harbin 150001 (China)

    2016-03-11

    We propose a classical analog of electromagnetically induced transparency in a cylindrical waveguide with undulated metallic walls. The transparency, induced by multi-mode interactions in waveguides, not only has a narrow line-width, but also consists of a single second-order transverse mode, which corresponds to the Bessel function distributions investigated extensively due to their unique characteristics. By increasing the thickness of sputtered gold layers of the waveguide, we demonstrate a frequency-agile single mode transparency phenomenon in a terahertz radiation. It is found that the center frequency of the transparency is linearly related to the gold thickness, indicating the achievement of a controllable single mode terahertz device. The field distributions at the cross-sections of outlets verify the single second mode transparency and indicate the mechanism of its frequency manipulation, which will significantly benefit the mode-control engineering in terahertz applications. - Highlights: • An analog of electromagnetically induced transparency in terahertz tubes is proposed. • A single second transverse mode of Bessel distributions is observed in the pass band. • The operating frequency can be linearly controlled by the sputtered gold thickness. • We can effectively manipulate the slow down factor of light by the gold thickness. • The transparency characteristics rely on the transition of multi-mode interactions.

  2. Intrinsic flux pinning mechanisms in different thickness MgB2 films

    Directory of Open Access Journals (Sweden)

    C. Yang

    2017-03-01

    Full Text Available MgB2 films in four thickness (60 nm, 200nm, 600nm and 1μm have been fabricated by hybrid physical–chemical vapor deposition technique (HPCVD. By measuring the magnetization hysteresis loops and the resistivity, we have obtained the transport and magnetic properties of the four films. After that, the pinning mechanisms in them were discussed. Comparing the pinning behaviors in these ultrathin films, thin films and thick films, it was found that there exist different pinning types in MgB2 films of different thickness. In combination with the study of the surface morphology, cross-section and XRD results, we concluded that MgB2 films had different growth modes in different growth stages. For thin films, films grew along c axis, and grain boundaries acted as surface pinning. While for thick films, films grew along c axis at first, and then changed to a-b axis growth. As a result, the a-b axis grains acted as strong volume pinning.

  3. Measuring method and device for thickness of pad welded joint of reactor pressure vessel

    International Nuclear Information System (INIS)

    Ara, Katsuyuki; Nakajima, Nobuya; Ebine, Noriya.

    1995-01-01

    A magnetic yoke having an optional magnetic path length and a magnetic path cross section is disposed in close contact with or adjacent to the surface of the pad welded joint of a reactor pressure vessel, to form a magnetic path by the magnetic yoke and the reactor pressure vessel. Then, the magnetic path yoke is magnetized to measure a distribution of a magnetic field generated on the surface of the pad welded joint or its vicinity to which the magnetic yoke is adapted to be in close contact or come close. Since the geometrical dimensions and the magnetic performances of a material of the magnetic yoke and the pressure vessel are previously determined and, the measured magnetic distribution changes only by the thickness of the pad welded joint, the thickness of the pad welded joint of the pressure vessel can be determined. Accordingly, the measuring method of the present invention can measure the thickness of the pad welded joint of the pressure vessel at a desired practical accuracy and at a resolution power of, for example, 0.1mm relative to the thickness of the seat welded joint of 5 to 10mm. (N.H.)

  4. Investigation on narrow-gap welding residual stresses in ultra-thick ring-type mockups

    Science.gov (United States)

    Liu, Chuan; Yang, Jiawei; Shi, Yifeng; Zhao, Yong

    2018-01-01

    The stress distributions within two ring-type mockups manufactured by multi-pass narrow-gap submerged welding were investigated by numerical simulations and experiments. The large mockup consisted of a 300 mm thick ring welded to a large cylinder, and the small one was a butt-welded joint consisted of two 300 mm thick curved plates. The effect of structure form on the stress in the heavy-section component was also investigated. Results show that the stress distribution in the small mockup is similar to that in the large one. The location where the minimum hoop and radial stresses appear at the weld centerline is decided by the weld metal height of the second welding step of the welding procedure used in the present study. In addition, a sudden stress change occurs near the top surface of the weld metal after the first welding step due to the strong stiffness of the mockups. For the 300 mm thick welded mockups investigated, the structure form has no evident effect on the shape of the through-thickness stress distribution at the weld centerline, which is determined by the welding procedure; however, the structure form can affect the value of the minimum stress.

  5. Ultrasonic guided wave tomography for wall thickness mapping in pipes

    Science.gov (United States)

    Willey, Carson L.

    . An inversion method that iteratively uses the forward model is then developed to form a map of wall thickness for the entire pipe section comprised between two ring arrays of ultrasonic transducers that encircle the pipe. It is shown that time independent parametric uncertainties relative to the pipe manufacturing tolerances, transducers position, and ultrasonic properties of the material of the pipe can be minimized through a differential approach that is aimed at determining the change in state of the pipe relative to a reference condition. On the other hand, time dependent parametric uncertainties, such as those caused by temperature variations, can be addressed by exploiting the spatial diversity of array measurements and the non-contact nature of electromagnetic acoustic transducers (EMATs). The range of possible applications of GWT to pipes is investigated through theoretical and numerical studies aimed at developing an understanding of how the performance of GWT varies depending on damage morphology, pipe geometry, and array configuration.

  6. 3-D mapping with ellipsometrically determined physical thickness ...

    Indian Academy of Sciences (India)

    Unknown

    The gel layer thus formed transformed to oxide layer on heating to 450°C for ~ 30 min. The physical thickness and the refractive index of the layer were measured ellipsometrically (Rudolph Auto EL II) at 632⋅8 nm. About 10 × 10 mm surface area of the silica layer was chosen for evaluation of thickness and refractive index.

  7. The Effect of Endometrial Thickness on In vitro Fertilization (IVF ...

    African Journals Online (AJOL)

    The value of measuring the endometrial thickness and studying the endometrial receptivity in the context of assisted conception remains a contentious issue. A prospective analysis was carried out to determine the effect of endometrial thickness on IVF - embryo transfer / ICSI outcome in dedicated Assisted Reproductive ...

  8. The velocity-thickness characteristics of the mangrove swamp low ...

    African Journals Online (AJOL)

    A total of 14 upholes were shot in the Mangrove Swamp of the Niger Delta of Nigeria. The aim of the survey was to determine the thickness and velocity of the low velocity layer (LVL). The velocities and thickness of the layers were computed from the reciprocals of the slopes of the straight-line segments using the FACE ...

  9. Kinematics and simulation methods to determine the target thickness

    International Nuclear Information System (INIS)

    Rosales, P.; Aguilar, E.F.; Martinez Q, E.

    2001-01-01

    Making use of the kinematics and of the particles energy loss two methods for calculating the thickness of a target are described. Through a computer program and other of simulation in which parameters obtained experimentally are used. Several values for a 12 C target thickness were obtained. It is presented a comparison of the obtained values with each one of the used programs. (Author)

  10. Impact of oxide thickness on gate capacitance – Modelling and ...

    Indian Academy of Sciences (India)

    of oxide thickness. The obtained threshold voltage is characteristic with the variation of oxide thickness and is in good agreement with the experimental results obtained by Bera et al [15]. Then, eq. (17) is plotted in MATLAB by using the necessary parameter values for. AlInN/GaN and AlGaN/GaN MOSHEMT to graphically ...

  11. Trochanteric Soft Tissue Thickness and Hip Fracture in Older Men

    OpenAIRE

    Nielson, Carrie M.; Bouxsein, Mary L.; Freitas, Sinara S.; Ensrud, Kristine E.; Orwoll, Eric S.

    2009-01-01

    Background: Greater thickness of the tissue extending laterally from the greater trochanter has been associated with a lower risk of hip fracture in women. The effect of trochanteric soft tissue thickness on the risk of incident hip fracture has not been evaluated in men.

  12. Pelvic floor muscle thickness measured by perineal ultrasonography

    DEFF Research Database (Denmark)

    Bernstein, Inge Thomsen; Juul, N; Grønvall, S

    1991-01-01

    Pelvic floor muscle thickness was assessed in nine healthy female physiotherapists by perineal sonography. All measurements were performed as triple-measurements. The aims were to assess the reliability of the measurements and to establish a reference material. The muscle thickness at rest...

  13. Thickness measurement of A-1 reactor caisson tube walls

    International Nuclear Information System (INIS)

    Prepechal, J.; Sladky, J.

    1974-01-01

    The equipment is described of measuring the thickness of caisson pipes built in the Bohunice A-1 reactor. The pulse-type ultrasonic thickness gauge is based on the reflection method using the double probe. The measurement accuracy is 0.1 mm. (J.B.)

  14. Thick melanoma: prognostic value of positive sentinel nodes

    NARCIS (Netherlands)

    Vermeeren, Lenka; van der Ent, Fred W. C.; Sastrowijoto, Prapto S. H.; Hulsewé, Karel W. E.

    2009-01-01

    BACKGROUND: Sentinel lymph node biopsy (SNB) is a widely accepted procedure used to accurately stage patients with melanoma. Its value in patients with thick melanoma (Breslow thickness >4 mm) is reason for discussion because of the generally poor prognosis of these patients. The purpose of this

  15. Effects of thickness on electronic structure of titanium thin films

    Indian Academy of Sciences (India)

    Effects of thickness on the electronic structure of e-beam evaporated thin titanium films were studied using near-edge X-ray absorption fine structure (NEXAFS) technique at titanium 2,3 edge in total electron yield (TEY) mode and transmission yield mode. Thickness dependence of 2,3 branching ratio (BR) of titanium was ...

  16. 30 CFR 816.105 - Backfilling and grading: Thick overburden.

    Science.gov (United States)

    2010-07-01

    ... to restore the disturbed area to its approximate original contour. More than sufficient spoil and other waste materials occur where the overburden thickness times the swell factor exceeds the combined thickness of the overburden and coal bed prior to removing the coal, so that after backfilling and grading...

  17. Is 'Education' a Thick Epistemic Concept? | Siegel | Philosophical ...

    African Journals Online (AJOL)

    Is 'education' a thick epistemic concept? The answer depends, of course, on the viability of the 'thick/thin' distinction, as well as the degree to which education is an epistemic concept at all. I will concentrate mainly on the latter, and will argue that epistemological matters are central to education and our philosophical ...

  18. Masseter muscle thickness in different skeletal morphology: An ultrasonographic study

    Directory of Open Access Journals (Sweden)

    Rani Sushma

    2010-01-01

    Full Text Available Background: The thickness of the masseter muscle during relaxation and contraction states was measured by ultrasonography. Subjects were classified according to their sagittal skeletal relationships. The association between muscle thickness and facial morphology was studied. Context: Masseter muscle thickness influences the skeletal patterns. Aim: To measure and compare the thickness of the masseter muscle in individuals with skeletal class I occlusion and skeletal class II malocclusions and to correlate its relationship with craniofacial morphology. Settings and Design: The study was conducted in a hospital setup and was designed to study the thickness of the masseter muscle in different skeletal morphologies. Materials and Methods: Seventy two individuals between the ages of 18 and 25 years were divided into Group I, Group IIA and Group IIB according to their skeletal relationships. Masseter muscle thickness was measured by ultrasonography. Eight linear and six angular cephalometric measurements were assessed. Statistical Analysis Used: Analysis of variance and Pearson′s correlation analysis. Results: There was a statistically significant difference in muscle thickness between subjects of different skeletal patterns. Significant positive correlation between masseter muscle thickness and posterior total face height, jarabak ratio, ramus height, mandibular length and significant negative correlations with mandibular plane angle, gonial angle and PP-MP angle were observed. Conclusion: This study indicates the strong association between the masseter muscle and skeletal morphology.

  19. Thickness effect in composite laminates in static and fatigue loading

    NARCIS (Netherlands)

    Lahuerta Calahorra, F.

    2017-01-01

    Thick Laminates (above 6mm) are increasingly present in large composites structures such as wind turbine blades. Designs are based on static and fatigue coupon tests performed on 1-4mm thin laminates. However, a thickness effect has been observed in limited available experimental data. For this

  20. The thickness effects of the side-grooved CCT specimen

    International Nuclear Information System (INIS)

    Machida, Kenji; Kikuchi, Masanori; Miyamoto, Hiroshi

    1988-01-01

    J IC tests were carried out on SUS 316 steel by means of the JSME R-curve method as well as the JSME stretched-zone width (SZW) method. The effects of side-grooves on the J in value at the onset of stable crack growth were investigated using CCT specimens of two thicknesses (B = 1 mm and 2 mm). The ratio of the net thickness to the gross thickness was maintained at 0.5. The J in values of the side-grooved CCT specimens of both thicknesses were considerably smaller than those of the 1 TCT specimen. The J in value of the side-grooved specimen of 2 mm thickness was smaller than that of the standard CCT specimen. Further, as the thickness of the specimen became thinner, the J in value decreased. In the case of 1 mm-thick CCT specimens with or without a side-groove, the contraction percentage of thickness was very large so that it was not appropriate to use these specimens for the fracture toughness test. In the case of the thin or side-grooved CCT specimens, the J-value, which is evaluated from the load versus displacement curve using Rice's formula, cannot estimate the J-integral at the central part of the specimen. Therefore, a J-integral estimation method would have to be established using 3-D elastic-plastic analysis. (author)

  1. Three-dimensional free vibration analysis of thick laminated circular ...

    African Journals Online (AJOL)

    Three-dimensional free vibration analysis of thick laminated circular plates. Sumit Khare, N.D. Mittal. Abstract. In this communication, a numerical analysis regarding free vibration of thick laminated circular plates, having free, clamped as well as simply-supported boundary conditions at outer edges of plates is presented.

  2. Stresses and strains in thick perforated orthotropic plates

    Science.gov (United States)

    A. Alshaya; John Hunt; R. Rowlands

    2016-01-01

    Stress and strain concentrations and in-plane and out-of-plane stress constraint factors associated with a circular hole in thick, loaded orthotropic composite plates are determined by three-dimensional finite element method. The plate has essentially infinite in-plane geometry but finite thickness. Results for Sitka Spruce wood are emphasized, although some for carbon...

  3. Faraday effect in hollow quantum cylinder of finite thickness

    International Nuclear Information System (INIS)

    Ismailov, T.G.; Jabrailova, G.G.

    2009-01-01

    The interband Faraday rotation in hollow quantum cylinder of finite thickness is theoretically investigated. Faraday rotation in the dependence on incident light energy for different values of cylinder thickness. It is seen that the resonance peaks appear on Faraday rotation curve. The roles of selection are obtained

  4. Origami-Inspired Folding of Thick, Rigid Panels

    Science.gov (United States)

    Trease, Brian P.; Thomson, Mark W.; Sigel, Deborah A.; Walkemeyer, Phillip E.; Zirbel, Shannon; Howell, Larry; Lang, Robert

    2014-01-01

    To achieve power of 250 kW or greater, a large compression ratio of stowed-to-deployed area is needed. Origami folding patterns were used to inspire the folding of a solar array to achieve synchronous deployment; however, origami models are generally created for near-zero-thickness material. Panel thickness is one of the main challenges of origami-inspired design. Three origami-inspired folding techniques (flasher, square twist, and map fold) were created with rigid panels and hinges. Hinge components are added to the model to enable folding of thick, rigid materials. Origami models are created assuming zero (or near zero) thickness. When a material with finite thickness is used, the panels are required to bend around an increasingly thick fold as they move away from the center of the model. The two approaches for dealing with material thickness are to use membrane hinges to connect the panels, or to add panel hinges, or hinges of the same thickness, at an appropriate width to enable folding.

  5. Mapping sediment thickness of Islamabad city using empirical relationships: Implications for seismic hazard assessment

    Science.gov (United States)

    Khan, Sarfraz; Khan, M. Asif

    2016-04-01

    borehole data. It is found out that there is a wide variation in soft-sediment thickness in the Islamabad area, but as a general rule, soft sediments are thicker adjacent to stream courses compared to the areas intervening the streams. The distribution of sediments in the studied area is illustrated by means of cross sections constructed from results of the microtremor analyses and available borehole data, which provides a visual distribution of the soft sediments underlying the Islamabad city.

  6. Non-contact Measurement of Remaining Thickness of Corroding Superheater Tubes. Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Borggreen, Kjeld; Storesund, Jan

    2006-10-15

    Corrosion of superheaters has become a severe problem in many biomass boilers and incineration plants. This new situation calls for frequent tube wall thickness testing of the superheaters during very short shut-downs. To meet this demand Electro Magnetic Acoustic Transducer (EMAT) candidates as substitute for conventional manually operated contact UT-transducers. The EMAT can contactlessly generate an ultrasonic wave in the interphase between the external oxide and the metal. This means that measurements can be undertaken much quicker and with a much higher coverage simultaneously, without preceding blast operations. It is the aim of the project to demonstrate the usefulness of two simple EMAT systems, Panametrics and Sonatest, for fast and reliable tube thickness inspections in difficult-to-access superheater sections. The present Phase 1 of the project involves testing of the performance of the two systems in laboratory with the following results: 1. Both instruments work well on plate, tube, and pipe samples assuming the presence of an external oxide layer formed at a temperature above approximately 400 deg C. 2. Both instruments work well on all types of ferritic and martensitic steels but not on austenitic steels. 3. Both instruments work well independent of the thickness of the active oxide layer. 4. Both instruments work well independent of tube diameter, wall thickness, and sample width. 5. Both instruments work well over a very large range of wall thicknesses. Minimum tube wall thickness is less than 1.8 mm. 6. The tolerable lift-off (free distance between transducer and tube surface) is 2.4 - 3.0 mm for Panametrics system and 3.6 - 4.8 mm for Sonatest's system. The tolerable lift-off is a measure of the thickness of ash deposits, which can be tolerated on the tube surface as well as the misplacement, which can be tolerated in case of remote tube testing. 7. The tolerable off-set between tube axis and probe axis is very large for both instruments (10

  7. Global Mapping of Oceanic and Continental Shelf Crustal Thickness and Ocean-Continent Transition Structure

    Science.gov (United States)

    Kusznir, Nick; Alvey, Andy; Roberts, Alan

    2017-04-01

    The 3D mapping of crustal thickness for continental shelves and oceanic crust, and the determination of ocean-continent transition (OCT) structure and continent-ocean boundary (COB) location, represents a substantial challenge. Geophysical inversion of satellite derived free-air gravity anomaly data incorporating a lithosphere thermal anomaly correction (Chappell & Kusznir, 2008) now provides a useful and reliable methodology for mapping crustal thickness in the marine domain. Using this we have produced the first comprehensive maps of global crustal thickness for oceanic and continental shelf regions. Maps of crustal thickness and continental lithosphere thinning factor from gravity inversion may be used to determine the distribution of oceanic lithosphere, micro-continents and oceanic plateaux including for the inaccessible polar regions (e.g. Arctic Ocean, Alvey et al.,2008). The gravity inversion method provides a prediction of continent-ocean boundary location which is independent of ocean magnetic anomaly and isochron interpretation. Using crustal thickness and continental lithosphere thinning factor maps with superimposed shaded-relief free-air gravity anomaly, we can improve the determination of pre-breakup rifted margin conjugacy and sea-floor spreading trajectory during ocean basin formation. By restoring crustal thickness & continental lithosphere thinning to their initial post-breakup configuration we show the geometry and segmentation of the rifted continental margins at their time of breakup, together with the location of highly-stretched failed breakup basins and rifted micro-continents. For detailed analysis to constrain OCT structure, margin type (i.e. magma poor, "normal" or magma rich) and COB location, a suite of quantitative analytical methods may be used which include: (i) Crustal cross-sections showing Moho depth and crustal basement thickness from gravity inversion. (ii) Residual depth anomaly (RDA) analysis which is used to investigate OCT

  8. Neutron cross sections

    CERN Document Server

    Hughes, Donald J; Dunworth, J V

    1957-01-01

    Neutron Cross Sections presents the principles of cross-section measurement and use, as well as sufficient theory so that the general behavior of cross sections is made understandable. This compilation is a direct result of experiences connected with the collection and evaluation of cross-section data during the past eight years at """"Sigma Centre"""", Brookhaven National Laboratory. Here, experimental results received from laboratories throughout the world are carefully evaluated and compiled in the curves and tables of the large volume Neutron Cross Sections, The most recent version of the

  9. Hybrid Carbon-Glass Fiber/Toughened Epoxy Thick Composite Joints Subject to Drop-Weight and Ballistic Impacts

    National Research Council Canada - National Science Library

    Liaw, Benjamin; Delale, Feridun

    2007-01-01

    ... No. DAAD19-02-R-0010 to conduct research on hybrid carbon-S2 glass fiber/toughened epoxy thick-section, hybrid interwoven composite joints subject to drop-weight and ballistic impacts. Dr. Basavaraju B. Raju of U.S...

  10. Estimation of in vivo cortical bone thickness using ultrasonic waves.

    Science.gov (United States)

    Mano, Isao; Horii, Kaoru; Hagino, Hiroshi; Miki, Takami; Matsukawa, Mami; Otani, Takahiko

    2015-07-01

    To verify the measurement of cortical bone thickness at the distal radius in vivo using an ultrasonic method. The method for estimating cortical bone thickness was derived from experiments with in vitro bovine specimens. Propagation time of echo waves and propagation time of slow waves were used for the estimation. The outside diameter of cortical bone and the cortical bone thickness at the distal 5.5 % site of radius were measured with the new ultrasonic bone measurement system, and the results were compared with X-ray pQCT clinical measurements. There was a high positive correlation (r: 0.76) between the cortical bone thickness measured by the new ultrasonic system and the X-ray pQCT results. We will be able to measure not only cancellous bone density but also cortical bone thickness in vivo using ultrasonic waves (without X-ray) safely and repeatedly.

  11. Choroidal thickness evaluation in paediatric patients with adenotonsillar hypertrophy.

    Science.gov (United States)

    Yenigun, A; Elbay, A; Hafiz, A M; Ozturan, O

    2017-09-01

    To investigate choroidal thickness using enhanced-depth imaging optical coherence tomography in paediatric patients with adenotonsillar hypertrophy, with comparison to healthy children, three months after adenotonsillectomy. The patients were assigned to three groups: an adenotonsillar hypertrophy group, an adenotonsillectomy group and a healthy control group. In all groups, subfoveal, temporal and nasal choroidal thickness measurements were taken. In the subfoveal, temporal and nasal regions, choroidal tissue was found to be significantly thinner in adenotonsillar hypertrophy children than healthy children (p = 0.012, p = 0.027 and p = 0.020). The subfoveal and temporal choroidal thickness measurements of adenotonsillar hypertrophy group cases were significantly decreased compared to those in the adenotonsillectomy group (p = 0.038 and p = 0.048). There was a significant association between decreased choroidal thickness and adenotonsillar hypertrophy. Adenotonsillar hypertrophy may play an important role in decreased choroidal thickness.

  12. Barium titanate thick films prepared by screen printing technique

    Directory of Open Access Journals (Sweden)

    Mirjana M. Vijatović

    2010-06-01

    Full Text Available The barium titanate (BaTiO3 thick films were prepared by screen printing technique using powders obtained by soft chemical route, modified Pechini process. Three different barium titanate powders were prepared: i pure, ii doped with lanthanum and iii doped with antimony. Pastes for screen printing were prepared using previously obtained powders. The thick films were deposited onto Al2O3 substrates and fired at 850°C together with electrode material (silver/palladium in the moving belt furnace in the air atmosphere. Measurements of thickness and roughness of barium titanate thick films were performed. The electrical properties of thick films such as dielectric constant, dielectric losses, Curie temperature, hysteresis loop were reported. The influence of different factors on electrical properties values was analyzed.

  13. Heel pad thickness: determination by high-resolution ultrasonography.

    Science.gov (United States)

    Gooding, G A; Stress, R M; Graf, P M; Grunfeld, C

    1985-04-01

    Heel pad thickness classically is increased in acromegaly and can also be noted in long-term Dilantin therapy. A high-resolution 10-MHz dedicated superficial small parts real-time scanner was used to evaluate heel pad thickness without the use of radiation and without the magnification inherent in the standard procedure, a lateral radiograph of the foot. Fifty-four patients were studied, and it was determined in 10 controls that heel pad thickness averaged 16.6 mm. In 38 diabetics without ulcers of the feet, the heel pad was 17.8 mm. A single treated acromegalic had a heel pad thickness of 21 mm. Ultrasonography offers an effective alternative to radiography in the measurement of heel pad thickness.

  14. The Thickness of Amalgamations and Cartesian Product of Graphs

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    Yang Yan

    2017-08-01

    Full Text Available The thickness of a graph is the minimum number of planar spanning subgraphs into which the graph can be decomposed. It is a measurement of the closeness to the planarity of a graph, and it also has important applications to VLSI design, but it has been known for only few graphs. We obtain the thickness of vertex-amalgamation and bar-amalgamation of graphs, the lower and upper bounds for the thickness of edge-amalgamation and 2-vertex-amalgamation of graphs, respectively. We also study the thickness of Cartesian product of graphs, and by using operations on graphs, we derive the thickness of the Cartesian product Kn □ Pm for most values of m and n.

  15. Development of Flat Slab – Column Interaction with Different Thickness

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    Binti Joohari Ilya

    2017-01-01

    Full Text Available Flat slab – column connection has received much attention in recent years due to its simplicity of construction where beam is not required to support the slab. Flat slab has many usages in the construction field and has been investigated as a potential building material. Despite its many benefits, flat slab is easily subjected to punching shear failure. A simple approach to minimize punching shear failure is by increasing the slab thickness. It is generally accepted that the performance of flat slab is improved by using shear reinforcement; however, little attention has been paid to the selection of thickness. This research focuses on the crack behaviour of flat slab due to different slab thickness. Two specimens with different slab thickness have been constructed and tested to obtain the flat slab strength and crack pattern behaviour. Increasing the slab thickness was found to improve the strength of the flat slab and minimize the deflection and crack appearance on the slab.

  16. Influence of thickness on properties of plasticized oat starch films

    Directory of Open Access Journals (Sweden)

    Melicia Cintia Galdeano

    2013-08-01

    Full Text Available The aim of this study was to investigate the effect of thickness (between 80 and 120 µm on apparent opacity, water vapor permeability and mechanical properties (tensile and puncture of oat starch films plasticized with glycerol, sorbitol, glycerol:sorbitol mixture, urea and sucrose. Films were stored under 11, 57, 76 and 90% relative humidity (RH to study the mechanical properties. It was observed that the higher the thickness, the higher was the opacity values. Films without the plasticizer were more opaque in comparison with the plasticized ones. Glycerol:sorbitol films presented increased elongation with increasing thickness at all RH. Puncture force showed a strong dependence on the film thickness, except for the films plasticized with sucrose. In general, thickness did not affect the water permeability.

  17. Thickness of unconsolidated deposits in the towns of Solon and Taylor, Cortland County, New York

    Science.gov (United States)

    Miller, Todd S.

    1999-01-01

    the south, east, west, and north slopes averages 92, 52, 62, and 22 ft, respectively. Hills that have thick till on their south slopes have been referred to as till-shadowed hills by Coates (1974), who attributes this characteristic to glaciers that deposited thick amounts of till on the downflow side of a hill (analogous to flowing streams or wind that deposit sediment on the lee side of an object). Because the till on the south slopes is relatively thick and typically has low permeability, these slopes have been considered as potential areas for waste-disposal sites.In 1997, the U.S. Geological Survey (USGS), in cooperation with the Cortland County Department of Planning, began a 1-year study to map the thickness of unconsolidated deposits and the extent of valley-fill aquifers in the Towns of Solon and Taylor (an area of 60 mi2) in eastern Cortland County.This report (1) depicts the thickness of unconsolidated deposits and the extent of valley-fill aquifers in the Towns of Solon and taylor in eastern Cortland County, (2) examines whether the "till-shadowed hill" concept developed by Coates (1966) is applicable in this area, and (3) provides three schematic geologic sections showing the thickness of unconsolidated deposits in the uplands in the northwestern part of the study area.

  18. Choroidal thickness after intravitreal ranibizumab injections for choroidal neovascularization

    Directory of Open Access Journals (Sweden)

    Ellabban AA

    2012-05-01

    Full Text Available Abdallah A Ellabban, Akitaka Tsujikawa, Ken Ogino, Sotaro Ooto, Kenji Yamashiro, Akio Oishi, Nagahisa YoshimuraDepartment of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, JapanPurpose: To study changes in choroidal thickness with ranibizumab treatment for choroidal neovascularization (CNV.Design: Prospective case series.Methods: This prospective study consisted of 60 CNV-affected eyes of 60 patients treated with intravitreal injections of ranibizumab using an on-demand protocol after an initial loading phase. The eyes studied included 20 with age-related macular degeneration (AMD, 20 with polypoidal choroidal vasculopathy (PCV, and 20 with myopic CNV. In the eyes with AMD and PCV, choroidal thickness at the fovea was measured with optical coherence tomography using enhanced depth imaging. In eyes with myopic CNV, the choroidal thickness was measured using standard optical coherence tomography without the enhanced depth imaging technique.Results: With ranibizumab treatment, central retinal thickness decreased significantly (P < 0.001 and visual acuity improved significantly (P < 0.001. However, central choroidal thickness (167.2 ± 108.3 µm showed no significant change at 1 month after the loading phase (165.2 ± 107.8 µm, P = 0.120 or at final examination (164.8 ± 107.7 µm, P = 0.115. At baseline, central retinal thickness in eyes with AMD was significantly greater that those with PCV (P = 0.005 or high myopia (P = 0.029. However, central choroidal thickness in eyes with myopic CNV was significantly thinner than in eyes with AMD (P < 0.001 or PCV (P < 0.001. In each type of disease, there was no significant change in central choroidal thickness with ranibizumab treatment.Conclusion: The effect of ranibizumab on the choroidal thickness is minimal, if any.Keywords: choroidal thickness, ranibizumab, optical coherence tomography

  19. A bend thickness sensitivity study of Candu feeder piping

    International Nuclear Information System (INIS)

    Li, M.; Aggarwal, M.L.; Meysner, A.; Micelotta, C.

    2005-01-01

    In CANDU reactors, feeder bends close to the connection at the fuel channel may be subjected to the highest Flow Accelerated Corrosion (FAC) and stresses. Feeder pipe stress analysis is crucial in the life extension of aging CANDU plants. Typical feeder pipes are interconnected by upper link plates and spacers. It is well known that the stresses at the bends are sensitive to the local bend thicknesses. It is also known from the authors' study (Li and et al, 2005) that feeder inter linkage effect is significant and cannot be ignored. The field measurement of feeder bend thickness is difficult and may be subjected to uncertainty in accuracy. Hence, it is desirable to know how the stress on a subject feeder could be affected by the bend thickness variation of the neighboring feeders. This effect cannot be evaluated by the traditional 'single' feeder model approach. In this paper, the 'row' and 'combined' models developed in the previous study (Li and et al, 2005), which include the feeder interactions, are used to investigate the sensitivity of bend thickness. A series of random thickness bounded by maximum and minimum measured values were applied to feeders in the model. The results show that an individual feeder is not sensitive to the bend thickness variation of the remaining feeders in the model, but depends primarily on its own bend thickness. The highest stress at a feeder always occurs when the feeder has the smallest possible bend thickness. A minimum acceptable bend thickness for individual feeders can be computed by an iterative computing process. The dependency of field thickness measurement and the amount of required analysis work can be greatly reduced. (authors)

  20. Residual stress measurements in a thick, dissimilar aluminum alloy friction stir weld

    International Nuclear Information System (INIS)

    Prime, Michael B.; Gnaeupel-Herold, Thomas; Baumann, John A.; Lederich, Richard J.; Bowden, David M.; Sebring, Robert J.

    2006-01-01

    Plates (25.4 mm thick) of aluminum alloys 7050-T7451 and 2024-T351 were joined in a butt joint by friction stir welding (FSW). A 54 mm long test specimen was removed from the parent plate, and cross-sectional maps of residual stresses were measured using neutron diffraction and the contour method. The stresses in the test specimen peaked at only about 32 MPa and had the conventional 'M' profile with tensile stress peaks in the heat-affected zone outside the weld. The asymmetric stress distribution is discussed relative to the FSW process and the regions of highest thermal gradients. The general agreement between the two measurement techniques validated the ability of each technique to measure the low-magnitude stresses, less than 0.05% of the elastic modulus. Subtle differences between the two were attributed to spatial variations in the unstressed lattice spacing (d 0 ) and also intergranular strains affecting the neutron results. The FSW stresses prior to relaxation from removal of the test specimen were estimated to have been about 43 MPa, demonstrating the ability of FSW to produce low-stress welds in even fairly thick sections. To avoid the estimated 25% stress relaxation from removing the test specimen, the specimen would have had to be quite long because the St. Venant's characteristic distance in this case was more related to the transverse dimensions of the specimen than to the plate thickness

  1. Thick Concrete Specimen Construction, Testing, and Preliminary Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, Dwight A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hoegh, Kyle [Univ. of Minnesota, Minneapolis, MN (United States); Khazanovich, Lev [Univ. of Minnesota, Minneapolis, MN (United States)

    2015-03-01

    The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years. Since many important safety structures in an NPP are constructed of concrete, inspection techniques must be developed and tested to evaluate the internal condition. In-service containment structures generally do not allow for the destructive measures necessary to validate the accuracy of these inspection techniques. This creates a need for comparative testing of the various nondestructive evaluation (NDE) measurement techniques on concrete specimens with known material properties, voids, internal microstructure flaws, and reinforcement locations. A preliminary report detailed some of the challenges associated with thick reinforced concrete sections and prioritized conceptual designs of specimens that could be fabricated to represent NPP concrete structures for using in NDE evaluation comparisons. This led to the construction of the concrete specimen presented in this report, which has sufficient reinforcement density and cross-sectional size to represent an NPP containment wall. Details on how a suitably thick concrete specimen was constructed are presented, including the construction materials, final nominal design schematic, as well as formwork and rigging required to safely meet the desired dimensions of the concrete structure. The report also details the type and methods of forming the concrete specimen as well as information on how the rebar and simulated defects were embedded. Details on how the resulting specimen was transported, safely anchored, and marked to allow access for systematic comparative NDE testing of defects in a representative NPP containment wall concrete specimen are also given. Data collection using the MIRA Ultrasonic NDE equipment and

  2. Choroidal and macular thickness changes induced by cataract surgery

    Directory of Open Access Journals (Sweden)

    Falcão MS

    2013-12-01

    Full Text Available Manuel S Falcão,1,2 Nuno M Gonçalves,2 Paulo Freitas-Costa,1,3 João B Beato,2 Amândio Rocha-Sousa,1,2 Ângela Carneiro,1,2 Elisete M Brandão,2 Fernando M Falcão-Reis1,21Department of Sense Organs, Faculty of Medicine, University of Porto, 2Department of Ophthalmology of Hospital de São João, 3Department of Anatomy, Faculty of Medicine, University of Porto, Porto, PortugalBackground: The aim of this study was to evaluate the effect of uneventful phacoemulsification on the morphology and thickness of the macula, the submacular choroid, and the peripapillary choroid.Methods: In 14 eyes from 14 patients, retinal macular thickness, choroidal submacular thickness, and choroidal peripapillary thickness were measured preoperatively and at one week and one month after phacoemulsification using enhanced depth imaging spectral domain optical coherence tomography. Changes in thickness of the different ocular tissues were evaluated.Results: There was a statistically significant increase in mean retinal macular thickness at one month. In horizontal scans, the mean increase was +8.67±6.75 µm (P<0.001, and in vertical scans, the mean increase was +8.80±7.07 µm (P=0.001. However, there were no significant changes in choroidal morphology in the submacular and peripapillary areas one month after surgery. In vertical scans, there was a nonsignificant increase in choroidal thickness (+4.21±20.2 µm; P=0.47 whilst in horizontal scans a nonsignificant decrease was recorded (−9.11±39.59 µm; P=0.41. In peripapillary scans, a nonsignificant increase in mean choroidal thickness was registered (+3.25±11.80 µm; P=0.36.Conclusion: Uncomplicated phacoemulsification induces nonpathologic increases in retinal macular thickness probably due to the inflammatory insult of the surgery; however these changes are not accompanied by significant changes in choroidal thickness. In the posterior segment, the morphologic response to the inflammatory insult of

  3. Carotid intima-media thickness in spondyloarthritis patients

    Directory of Open Access Journals (Sweden)

    Thelma Larocca Skare

    Full Text Available CONTEXT AND OBJECTIVE Accelerated atherosclerosis has become a major problem in rheumatic inflammatory disease. The aim here was to analyze carotid intima-media thickness (IMT in spondyloarthritis (SpA patients and correlate this with clinical parameters and inflammatory markers. DESIGN AND SETTING Cross-sectional analytical study at Rheumatology Outpatient Clinic, Evangelical University Hospital, Curitiba. METHODS IMTs (measured using Doppler ultrasonography of 36 SpA patients were compared with controls. The IMT in SpA patients was associated with inflammatory markers, like erythrocyte sedimentation rate (ESR, C-reactive protein (CRP and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI; and with clinical parameters, like axial or peripheral involvement, dactylitis, HLA B27, uveitis occurrence, Bath Ankylosing Spondylitis Functional Index (BASFI and lipid profile. RESULTS The mean IMT in SpA patients was 0.72 ± 0.21 mm; in controls, 0.57 ± 0.13 mm (P = 0.0007. There were no associations with ESR, CRP, BASDAI or clinical data. In univariate analysis, greater IMT was seen in patients with longer disease duration (P = 0.014; Pearson R = 0.40; 95% confidence interval, CI = 0.06 to 0.65; higher triglycerides (P = 0.02; Spearman R = 0.37; 95% CI = 0.03 to 0.64; and older age (P = 0.0014; Pearson R 0.51; 95% CI = 0.21 to 0.72. CONCLUSION SpA patients have a higher degree of subclinical atherosclerosis than in controls, thus supporting clinical evidence of increased cardiovascular risk in rheumatic patients.

  4. Innervation of the thick ascending limb of Henle

    Energy Technology Data Exchange (ETDEWEB)

    Barajas, L.; Powers, K.V.

    1988-08-01

    The overlap of accumulations of autoradiographic grains (AAGs) on profiles of the thick ascending limb of Henle (TALH) was measured in autoradiograms of sections from rat kidneys with monoaminergic nerves labeled by means of tritiated norepinephrine. The amount of AAG overlap was used as an indirect means of quantifying innervation along the TALHs of superficial, mid-cortical, and juxtamedullary nephrons. The density of innervation along the TALH showed nephron heterogeneity; the juxtamedullary nephrons with a high pre- and postjuxtaglomerular apparatus (JGA) TALH density of innervation and the upper and midcortical nephrons with high TALH innervation densities at the level of the JGA. The pre-JGA TALH of the juxtamedullary nephrons had a significantly higher (P less than 0.001) density of innervation than the midcortical or superficial nephrons. The TALHs of juxtamedullary nephrons were found to have substantially more innervation than the TALHs of the other nephrons. For all three populations of nephrons, the pre-JGA TALH had the greatest amount of innervation. Neural regulation of TALH function would occur mainly along the pre-JGA and level of the JGA TALH. This regulation would increase TALH NaCl reabsorption (decrease luminal NaCl concentration) and therefore influence 1) the urinary concentrating mechanism, and 2) renin secretion via the macula densa mechanism. The innervation of the TALH was predominantly associated with the vasculature of the TALH's own nephron. However, innervation associated with medullary ray capillary beds from deeper nephrons was observed on pre-JGA TALHs from superficial and midcortical nephrons.

  5. Innervation of the thick ascending limb of Henle

    International Nuclear Information System (INIS)

    Barajas, L.; Powers, K.V.

    1988-01-01

    The overlap of accumulations of autoradiographic grains (AAGs) on profiles of the thick ascending limb of Henle (TALH) was measured in autoradiograms of sections from rat kidneys with monoaminergic nerves labeled by means of tritiated norepinephrine. The amount of AAG overlap was used as an indirect means of quantifying innervation along the TALHs of superficial, mid-cortical, and juxtamedullary nephrons. The density of innervation along the TALH showed nephron heterogeneity; the juxtamedullary nephrons with a high pre- and postjuxtaglomerular apparatus (JGA) TALH density of innervation and the upper and midcortical nephrons with high TALH innervation densities at the level of the JGA. The pre-JGA TALH of the juxtamedullary nephrons had a significantly higher (P less than 0.001) density of innervation than the midcortical or superficial nephrons. The TALHs of juxtamedullary nephrons were found to have substantially more innervation than the TALHs of the other nephrons. For all three populations of nephrons, the pre-JGA TALH had the greatest amount of innervation. Neural regulation of TALH function would occur mainly along the pre-JGA and level of the JGA TALH. This regulation would increase TALH NaCl reabsorption (decrease luminal NaCl concentration) and therefore influence 1) the urinary concentrating mechanism, and 2) renin secretion via the macula densa mechanism. The innervation of the TALH was predominantly associated with the vasculature of the TALH's own nephron. However, innervation associated with medullary ray capillary beds from deeper nephrons was observed on pre-JGA TALHs from superficial and midcortical nephrons

  6. Transverse resistive wall impedances and shielding effectiveness for beam pipes of arbitrary wall thickness

    Directory of Open Access Journals (Sweden)

    A. M. Al-Khateeb

    2007-06-01

    Full Text Available Using field matching techniques, closed form analytic expressions for the transverse impedance and for the shielding effectiveness of a smooth cylindrical beam pipe of arbitrary thickness are presented. In the limit of thick and thin beam pipes the well-known expressions are reproduced. The transverse transmission coefficient is compared with the longitudinal one that has been obtained in our previous work [A. M. Al-Khateeb, O. Boine-Frankenheim, R. W. Hasse, and I. Hofmann, Phys. Rev. E 71, 026501 (2005.PLEEE81063-651X10.1103/PhysRevE.71.026501]. The results are applied to the heavy ion synchrotron SIS 18 and to the planned SIS 100 at GSI. In both machines the stainless steel beam pipe in the dipole sections is much thinner than the skin depths at the revolution frequency and, therefore, the impedance value and the transmission are of concern.

  7. Measurement of the thickness of tubes with the aid of an internal ultrasonic probe

    International Nuclear Information System (INIS)

    Boulanger, G.; Furlan, J.

    1984-10-01

    This study concerns the adjustment of internal probes for ultrasonic testing of small tubes (internal diameter from 20 to 42 mm). The present probes allow to measure the thickness in the straight parts of these tubes, and can pass the curved parts. The principle of the measurement is presented: a annular transducer emits an ultrasonic beam to a conic mirror which reflects this last one perpendicular to the tube. The annular piezo-electric element of the transducers are divided in 8 sectors which give as much measurements by section. An electronic apparatus has been fitted, the MEPUS 8S, which realizes a quick commutation between the sectors and makes the measurement of the real or the relative thickness for each channel. A test on site has been undertaken to test the capacities of the system in an industrial environment [fr

  8. Statistical Analyses of AY-101 Ultrasonic Measurements of Wall Thickness

    International Nuclear Information System (INIS)

    Weier, Dennis R.

    2002-01-01

    Tank AY-101 wall thicknesses have been measured using ultrasonic (UT) images. Interest is in using the available data to estimate a worst-case minimum wall thickness for regions of the tank that remain unexamined with the UT approach. Each UT image can provide the wall thickness at a very large number of pixels, but only the minimum value for each image is used in this work. Since the data arise in this manner, one of several candidate statistical extreme value distributions should successfully fit these reported minimum values. Given a set of multiple UT images and the resulting minimum measured wall thicknesses, extreme value distributions are fit to the data with subsequent extrapolations made to estimate the minimum measured wall thickness expected for the entire tank. Such a minimum estimate incorporates both the variability in wall thicknesses and the uncertainty associated with the measurement method. Uncertainties of the estimated parameters are also derived and used in propagation of variance methods to obtain confidence bounds on the estimated minimum measured wall thickness as well

  9. Measurement of thickness of highly inhomogeneous crude oil slicks.

    Science.gov (United States)

    Cheemalapati, Surya; Forth, Heather P; Wang, Hao; Konnaiyan, Karthik Raj; Morris, Jeffrey M; Pyayt, Anna L

    2017-04-10

    As part of the Deepwater Horizon toxicity testing program, a number of laboratories generated oil slicks in the laboratory to study potential toxic effects of these oil slicks on aquatic organisms. Understanding the details of how these slicks affect aquatic organisms requires careful correlation between slick thickness and the observed detrimental effects. Estimating oil film thickness on water can be challenging since the traditional color-based technique used in the field is very imprecise. Also, as we demonstrate here, the films formed on the water surface are highly nonuniform on a microscale level, and thus uniform thin film thickness measurement techniques based on optical interference do not work. In this paper, we present a method that estimates the local thickness of weathered oil slicks formed on artificial seawater using light transmission and Beer-Lambert's law. Here, we demonstrate results of careful calibration together with the actual thickness estimation. Due to the heterogeneity of the slicks formed, we present slick thickness as a range of thicknesses collected from multiple points within the oil slick. In all the experiments we used oil samples provided by the Natural Resource Damage Assessment toxicity testing program for the Deepwater Horizon oil spill. Therefore, this study has an important practical value and successfully addresses unique challenges related to measurements involving complex, viscous, paste-like heterogeneous substances such as weathered crude oil.

  10. Gauging the Galactic thick disk with RR Lyrae stars

    Directory of Open Access Journals (Sweden)

    Cruz G.

    2012-02-01

    Full Text Available In this contribution we present results from the QUEST RR Lyrae Survey of the thick disk. The survey spans ~480 sq. deg. at low latitude |b| < 30°, with multi-epoch VRI observations, obtained with the QUEST-I camera at the 1m Jürgen Stock Schmidt telescope located at the National Astronomical Observatory of Venezuela. This constitutes the first deep RR Lyrae survey of the Galactic thick disk conducted at low galactic latitudes, covering simultaneously a large range in radial (8thick disk structural parameters from in situ RR Lyrae stars having accurate distances (errors <7% and individual reddenings derived from each star’s color curve at minimum light. Moreover, the use of RR Lyrae stars as tracers ensures negligible contamination from the Galactic thin disk. We find a thick disk mean scale height hZ = 0.94 ± 0.11kpc and scale length hR = 3.2 ± 0.4kpc, derived from the vertical and radial mean density profiles of RR Lyrae stars. We also find evidence of thick disk flaring and results that may suggest the thick disk radial density profile shows signs of antitruncation. We discuss our findings in the context of recent thick disk formation models.

  11. Knee cartilage segmentation and thickness computation from ultrasound images.

    Science.gov (United States)

    Faisal, Amir; Ng, Siew-Cheok; Goh, Siew-Li; Lai, Khin Wee

    2018-04-01

    Quantitative thickness computation of knee cartilage in ultrasound images requires segmentation of a monotonous hypoechoic band between the soft tissue-cartilage interface and the cartilage-bone interface. Speckle noise and intensity bias captured in the ultrasound images often complicates the segmentation task. This paper presents knee cartilage segmentation using locally statistical level set method (LSLSM) and thickness computation using normal distance. Comparison on several level set methods in the attempt of segmenting the knee cartilage shows that LSLSM yields a more satisfactory result. When LSLSM was applied to 80 datasets, the qualitative segmentation assessment indicates a substantial agreement with Cohen's κ coefficient of 0.73. The quantitative validation metrics of Dice similarity coefficient and Hausdorff distance have average values of 0.91 ± 0.01 and 6.21 ± 0.59 pixels, respectively. These satisfactory segmentation results are making the true thickness between two interfaces of the cartilage possible to be computed based on the segmented images. The measured cartilage thickness ranged from 1.35 to 2.42 mm with an average value of 1.97 ± 0.11 mm, reflecting the robustness of the segmentation algorithm to various cartilage thickness. These results indicate a potential application of the methods described for assessment of cartilage degeneration where changes in the cartilage thickness can be quantified over time by comparing the true thickness at a certain time interval.

  12. Metallicity gradient of the thick disc progenitor at high redshift

    Science.gov (United States)

    Kawata, Daisuke; Allende Prieto, Carlos; Brook, Chris B.; Casagrande, Luca; Ciucă, Ioana; Gibson, Brad K.; Grand, Robert J. J.; Hayden, Michael R.; Hunt, Jason A. S.

    2018-01-01

    We have developed a novel Markov Chain Monte Carlo chemical 'painting' technique to explore possible radial and vertical metallicity gradients for the thick disc progenitor. In our analysis, we match an N-body simulation to the data from the Apache Point Observatory Galactic Evolution Experiment survey. We assume that the thick disc has a constant scaleheight and has completed its formation at an early epoch, after which time radial mixing of its stars has taken place. Under these assumptions, we find that the initial radial metallicity gradient of the thick disc progenitor should not be negative, but either flat or even positive, to explain the current negative vertical metallicity gradient of the thick disc. Our study suggests that the thick disc was built-up in an inside-out and upside-down fashion, and older, smaller and thicker populations are more metal poor. In this case, star-forming discs at different epochs of the thick disc formation are allowed to have different radial metallicity gradients, including a negative one, which helps to explain a variety of slopes observed in high-redshift disc galaxies. This scenario helps to explain the positive slope of the metallicity-rotation velocity relation observed for the Galactic thick disc. On the other hand, radial mixing flattens the slope of an existing gradient.

  13. Comparison of Different Approaches for Measuring Tibial Cartilage Thickness

    Directory of Open Access Journals (Sweden)

    Maier Jennifer

    2017-07-01

    Full Text Available Osteoarthritis is a degenerative disease affecting bones and cartilage especially in the human knee. In this context, cartilage thickness is an indicator for knee cartilage health. Thickness measurements are performed on medical images acquired in-vivo. Currently, there is no standard method agreed upon that defines a distance measure in articular cartilage. In this work, we present a comparison of different methods commonly used in literature. These methods are based on nearest neighbors, surface normal vectors, local thickness and potential field lines. All approaches were applied to manual segmentations of tibia and lateral and medial tibial cartilage performed by experienced raters. The underlying data were contrast agent-enhanced cone-beam C-arm CT reconstructions of one healthy subject’s knee. The subject was scanned three times, once in supine position and two times in a standing weight-bearing position. A comparison of the resulting thickness maps shows similar distributions and high correlation coefficients between the approaches above 0.90. The nearest neighbor method results on average in the lowest cartilage thickness values, while the local thickness approach assigns the highest values. We showed that the different methods agree in their thickness distribution. The results will be used for a future evaluation of cartilage change under weight-bearing conditions.

  14. Effect of oral Colchicine on Peripapillary retinal nerve fiber layer thickness in patients with familial Mediterranean fever.

    Science.gov (United States)

    Tanyıldız, Burak; Tezcan, Mehmet Engin; Kandemir, Baran; Günaydın, Nesrin Tutaş; Göktaş, Eren; Tangılntız, Aise; Arsan, Aysu Karatay

    2018-02-05

    The purpose of this study is to investigate whether oral colchicine has an effect on peripapillary retinal nerve fiber layer (pRNFL) thickness of familial Mediterranean fever (FMF) patients. We conducted a cross sectional study by comparing pRNFL thickness of FMF patients on colchicine (treated group), newly diagnosed colchicine naïve FMF patients (untreated group) and healthy controls. The study included 66 FMF patients and 32 healthy control subjects. Treated FMF patients were grouped according to colchicine use, duration of use and dosage. pRNFL thickness of the patients and controls were measured by using optical coherence tomography and the measurements were compared. No statistically significant difference was found between the pRNFL thickness in untreated group, treated group and the healthy control group (all p > 0.05). No statistically significant difference was found between pRNFL thickness in the healthy control group and FMF patients grouped according to duration or dosage of colchicine use (all p > 0.05). According to our study, FMF and oral colchicine use had no statistically significant effect on pRNFL thickness.

  15. The Sonographic Correlation between The Sternocleidomastoid Muscle Thickness and the Prognosis of Congenital Muscular Torticollis

    International Nuclear Information System (INIS)

    Lim, Dae Keon; Kwon, Woo Cheol; Cha, Seung Whan; Yoo, Ho Seok; Lim, Sang Hyeok; Park, Jeong Mee; Kim, Myung Soon

    2009-01-01

    We wanted to predict the prognosis of patients with CMT by the A/N ratio of the thickness and the circumference of the SCM muscle on ultrasonography, and we wanted to correlate the echogenecity of the affected muscle and the prognosis. Ultrasonography was performed on 24 patients from June 2004 to March 2007. We measured the thickness and the cross sectional circumference of the SCM muscle at three levels; below the mastoid process, at the level of the carotid artery bifurcation and at the level of the sternum and clavicle. The ratio of the affected side to the normal side (the A/N ratio) of the SCM muscle was calculated. We performed followed up ultrasonography at 2 months intervals until the end of treatment. The Wilcoxon signed-rank test was used to correlate the A/N ratio before and after the treatment. Spearman's rank test was used to correlate the A/N ratio and the total treatment duration. Paired T-tests were used to correlate the echogenecity of the SCM muscle and the treatment duration divided by less than or greater than 12 months. With measuring the thickness of the SCM muscle, the A/N ratio after treatment (1.36) was decreased compared with the initial A/N ratio (2.31) (p<0.05). The correlation between the A/N ratio of the thickness with the total treatment duration was statistically significant (p<0.05). The echogenecity of the affected SCM muscle was not correlated with the duration of treatment. The A/N ratio of the thickness of the SCM muscle is useful to predict the prognosis of patients with CMT

  16. The influence of adhesive thickness on the microtensile bond strength of three adhesive systems.

    Science.gov (United States)

    D'Arcangelo, Camillo; Vanini, Lorenzo; Prosperi, Gianni Domenico; Di Bussolo, Giulia; De Angelis, Francesco; D'Amario, Maurizio; Caputi, Sergio

    2009-04-01

    To evaluate the effects of multiple adhesive layers of three etch-and-rinse adhesives on both adhesive thickness and microtensile bond strength (microTBS). Midcoronal occlusal dentin of 36 extracted human molars was used. Teeth were randomly assigned to 3 groups (EB, XP, PQ) according to the adhesive system to be used: PQ1 (Ultradent) (PQ), EnaBond (Micerium) (EB), or XP Bond (Dentsply/DeTrey) (XP). Specimens from each group were further divided into three subgroups according to the number of adhesive coatings (1, 2, or 3). In all subgroups, each adhesive layer was light cured before application of each additional layer. After bonding procedures, composite crowns were incrementally built up. Specimens were sectioned perpendicular to the adhesive interface to produce multiple beams, approximately 1 mm2 in area. Beams were tested under tension at a crosshead speed of 0.5 mm/min until failure. Adhesive thicknesses and failure modes were evaluated with SEM. The microTBS data and mean adhesive thickness were analyzed by two-way ANOVA and multiple-comparison Tukey's test (alpha = 0.05). The mean bond strength (in MPa (SD)) of group EB gradually increased from 1 to 3 consecutive coatings (27.02 (9.38) to 44.32 (4.93), respectively) (p adhesive coatings. The mean thickness of the adhesive layer (in microm (SD)) significantly increased with the number of coatings (p adhesive failure between adhesive and dentin. The XP3 and PQ3 subgroups showed a greater number of total cohesive failure in adhesive. Multiple adhesive coats significantly affected bond strength to dentin. An excess of adhesive layer thickness can negatively influence the strength and the quality of adhesion.

  17. Choroidal Thickness in Eyes with Fuchs Uveitis Syndrome.

    Science.gov (United States)

    Kardes, Esra; Sezgin Akçay, Betül Ilkay; Unlu, Cihan; Ergin, Ahmet

    2017-04-01

    This study measured the macular thickness, peripapillary retinal nerve fiber layer (RNFL) thickness, subfoveal choroidal thickness (SFCT), and ganglion cell complex (GCC) thickness in eyes with Fuchs uveitis syndrome (FUS). In total, 25 patients with unilateral FUS were enrolled. The diagnosis of FUS was based on the presence of several of the following clinical features: absence of acute symptoms and ciliary injection; small to medium-sized and stellate keratic precipitates (KP) diffusely scattered on the entire corneal endothelium; chronic low-grade anterior chamber inflammation; iris stromal atrophy with or without heterochromia; lack of posterior synechiae; iris nodules; and vitreous cells and debris. Spectral domain optical coherence tomography (SD-OCT; RTVue-100 OCT) was used to obtain the measurements. The SFCT, RNFL thickness, macular retinal thickness, and GCC thickness of the eyes with FUS were measured and compared with those of the uninvolved fellow eyes. A paired samples t-test was used for statistical analyses. A value of pHeterochromia was observed in 24% of the eyes, iris nodules in 36% of the eyes, lens opacity in 44% of the eyes, and vitreous cells and debris in 88% of the eyes. The mean SFCT was significantly thinner in eyes with FUS (296.47 ± 32.29 µm) than in the fellow eyes without FUS (324.47 ± 26.73 µm; p = 0.001). The mean average GCC thickness was found to be 101.09 ± 5.46 µm in eyes with FUS and 103.80 ± 6.65 µm in eyes without FUS (p = 0.023). There were no significant differences in the mean RNFL and macular thickness values. We detected subfoveal choroidal thinning in eyes with FUS when compared with the uninvolved fellow eyes. In our opinion, thinning of the SFCT in FUS might be associated with autoimmune responses and chronic inflammatory processes.

  18. β-ray photography of lyophilized animal sections

    International Nuclear Information System (INIS)

    Baba, Shigeo; Kimata, Hideki; Matsuzawa, Takashi

    1997-01-01

    A new photographic method that images the density distribution of lyophilized animal sections approximately 50 μm in thickness is described. The new method involves sandwiching the animal section between a radiation sensor and a 147 Pm planar radiation source. Either conventional photographic film or an imaging plate for radioluminography can be used as the sensor. The method described herein will find promising applications in whole body autoradiography as well as in the study of osteoporosis in experimental animals. (Author)

  19. Mitigating the Risk of Stress Corrosion of Austenitic Stainless Steels in Advanced Gas Cooled Reactor Boilers

    International Nuclear Information System (INIS)

    Bull, A.; Owen, J.; Quirk, G.; G, Lewis; Rudge, A.; Woolsey, I.S.

    2012-09-01

    Advanced Gas-Cooled Reactors (AGRs) operated in the UK by EDF Energy have once-through boilers, which deliver superheated steam at high temperature (∼500 deg. C) and pressure (∼150 bar) to the HP turbine. The boilers have either a serpentine or helical geometry for the tubing of the main heat transfer sections of the boiler and each individual tube is fabricated from mild steel, 9%Cr1%Mo and Type 316 austenitic stainless steel tubing. Type 316 austenitic stainless steel is used for the secondary (final) superheater and steam tailpipe sections of the boiler, which, during normal operation, should operate under dry, superheated steam conditions. This is achieved by maintaining a specified margin of superheat at the upper transition joint (UTJ) between the 9%Cr1%Mo primary superheater and the Type 316 secondary superheater sections of the boiler. Operating in this mode should eliminate the possibility of stress corrosion cracking of the Type 316 tube material on-load. In recent years, however, AGRs have suffered a variety of operational problems with their boilers that have made it difficult to maintain the specified superheat margin at the UTJ. In the case of helical boilers, the combined effects of carbon deposition on the gas side and oxide deposition on the waterside of the tubing have resulted in an increasing number of austenitic tubes operating with less than the specified superheat margin at the UTJ and hence the possibility of wetting the austenitic section of the boiler. Some units with serpentine boilers have suffered creep-fatigue damage of the high temperature sections of the boiler, which currently necessitates capping the steam outlet temperature to prevent further damage. The reduction in steam outlet temperature has meant that there is an increased risk of operation with less than the specified superheat margin at the UTJ and hence stress corrosion cracking of the austenitic sections of the boiler. In order to establish the risk of stress

  20. Safety of carbon fibre reinforced plastic hollow sections in ...

    African Journals Online (AJOL)

    Hollow CFRP columns having different sizes and material thicknesses were modeled using ABAQUS/CAE three-dimensional non-linear finite element analysis and the results obtained are used to measure the deformation under compression. All loads used were Euler's critical buckling load. Steel hollow sections were also ...

  1. Sea ice thickness retrieval from L-band radiometry

    Science.gov (United States)

    Kaleschke, L.; Maaß, N.; Hendricks, S.; Heygster, G.; Tonboe, R.

    2008-12-01

    Soil Moisture and Ocean Salinity (SMOS) is an earth observation mission developed by the European Space Agency to be launched in 2009. The main objective is to provide global measurements of soil moisture over land and sea surface salinity over ocean from L-band (1.4 GHz) radiometric observations. An exciting spin-off is the retrieval of sea ice thickness which we demonstrate to be possible due to the large penetration depth at L-band. SMOS will provide sea ice thickness information complementary to those from altimeters because of the expected sensitivity for thin ice thickness variations. Moreover, SMOS will provide data with an almost global coverage every second day. A three layer (ocean-ice-atmosphere) dielectric slab model is used to calculate the brightness temperature as a function of ice thickness and the dielectric properties. The dielectric properties depend on the relative brine volume as a function of bulk salinity and temperature. A model for the brightness temperature of a mixture of open water and sea ice reveals that the parameters ice concentration and thickness can hardly be retrieved both simultaneously. With the assumption of a closed ice cover the retrieval of ice thickness is feasible. The model calculations suggest a thickness sensitivity of up to 150 cm for low salinity (multi year or brackish) sea ice at low temperatures. At temperatures approaching the melting point the thickness sensitivity reduces to a few centimeters. For first year ice the modeled thickness sensitivity is roughly half a meter. The brightness temperature at 1.4 GHz (L-band) was measured in the Bothnia in Bay in March 2007 as part of the SMOS Sea-Ice campaign. The research aircraft was equipped with the Technical University of Denmark (TUD) Electromagnetics Institute Radiometer (EMIRAD). The EMIRAD measurements were coordinated with helicopter EM ice thickness measurements. The campaign was conducted under non- favorable conditions with temperatures around the melting

  2. Optical methods for thickness measurements on thin metal films.

    Science.gov (United States)

    Pokrowsky, P

    1991-08-01

    The thickness and the dielectric constants of thin metal films on glass substrates are determined by two different methods. The first method is a combination of transmission and ellipsometer measurements (TELL method) and the second is based on attenuated total reflection (ATR method in the Kretschmann arrangement). For comparison, both methods are applied to gold films within a thickness range of 20-80 nm. Furthermore, the TELL method was applied to chromium films of thicknesses up to 150 nm. All experiments are done with a He-Ne laser at 633-nm wavelength.

  3. Control for monitoring thickness of high temperature refractory

    Science.gov (United States)

    Caines, M.J.

    1982-11-23

    This invention teaches an improved monitoring device for detecting the changes in thickness of high-temperature refractory, the device consists of a probe having at least two electrically conductive generally parallel elements separated by a dielectric material. The probe is implanted or embedded directly in the refractory and is elongated to extend in line with the refractory thickness to be measured. Electrical inputs to the conductive elements provide that either or both the electrical conductance or capacitance can be found, so that charges over lapsed time periods can be compared in order to detect changes in the thickness of the refractory.

  4. Synthesis of nanometre-thick MoO3 sheets

    Science.gov (United States)

    Kalantar-Zadeh, Kourosh; Tang, Jianshi; Wang, Minsheng; Wang, Kang L.; Shailos, Alexandros; Galatsis, Kosmas; Kojima, Robert; Strong, Veronica; Lech, Andrew; Wlodarski, Wojtek; Kaner, Richard B.

    2010-03-01

    The formation of MoO3 sheets of nanoscale thickness is described. They are made from several fundamental sheets of orthorhombic α-MoO3, which can be processed in large quantities via a low cost synthesis route that combines thermal evaporation and mechanical exfoliation. These fundamental sheets consist of double-layers of linked distorted MoO6 octahedra. Atomic force microscopy (AFM) measurements show that the minimum resolvable thickness of these sheets is 1.4 nm which is equivalent to the thickness of two double-layers within one unit cell of the α-MoO3 crystal.

  5. Pelvic floor muscle thickness measured by perineal ultrasonography

    DEFF Research Database (Denmark)

    Bernstein, Inge Thomsen; Juul, N; Grønvall, S

    1991-01-01

    Pelvic floor muscle thickness was assessed in nine healthy female physiotherapists by perineal sonography. All measurements were performed as triple-measurements. The aims were to assess the reliability of the measurements and to establish a reference material. The muscle thickness at rest...... and at contraction was 9.4 +/- 0.8 mm and 11.5 +/- 1.1 mm respectively (mean +/- SD). Contraction increased the thickness by 2.2 +/- 0.8 mm or 23 +/- 8%. The intra- and inter observer standard deviation of the estimate was in the range of 4-6%. In conclusion, we find the reliability of the measurements acceptable....

  6. Assessment of iris surface features and their relationship with iris thickness in Asian eyes.

    Science.gov (United States)

    Sidhartha, Elizabeth; Gupta, Preeti; Liao, Jiemin; Tham, Yih-Chung; Cheung, Carol Y; He, Mingguang; Wong, Tien Y; Aung, Tin; Cheng, Ching-Yu

    2014-05-01

    To assess iris surface features in Asian eyes and examine their associations with iris thickness measured by anterior segment optical coherence tomography (AS OCT). Cross-sectional study. We recruited 250 subjects from the Singapore Malay Eye Study. We obtained standardized slit-lamp photographs and developed a grading system assessing iris crypts (by number and size), furrows (by number and circumferential extent), and color (higher grade denoting darker iris). Vertical and horizontal cross-sections of the anterior chamber were imaged using AS OCT. Intragrader and intergrader agreements in the grading of iris surface were assessed by weighted κ (κ(w)) statistic. Associations of the average iris thickness with the grade of iris features were assessed using linear regression analysis. Frequency and size of iris crypts, furrows, and color; iris thickness at 750 μm (IT750) and 2000 μm (IT2000) from the scleral spur; and maximum iris thickness (ITM) averaged from the 4 quarters. Three hundred sixty-four eyes had complete and gradable data for crypts and color; 330 eyes were graded for furrows. The grading scheme showed good intragrader (crypt κ(w) = 0.919, furrow κ(w) =0.901, color κ(w) = 0.925) and intergrader (crypt κ(w) = 0.775, furrow κ(w) = 0.836, color κ(w) = 0.718) agreements. Higher crypt grade was associated independently with thinner IT750 (β [change in iris thickness per grade higher] = -0.007; P = 0.029), IT2000 (β = -0.018; P iris was also associated with thicker IT750 (β = 0.014; P = 0.001). Iris surface features, assessed and measured from slit-lamp photographs, correlate well with iris thickness. Irises with more crypts are thinner; irises with more extensive furrows and darker color are thicker peripherally. These findings may provide another means to assess angle closure risk based on iris features. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  7. Non-contact Measurement of Remaining Thickness of Corroding Superheater Tubes. Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Borggreen, Kjeld; Storesund, Jan

    2007-12-15

    The Electro Magnetic Acoustic Transducer (EMAT) is a contactless thickness gauge for detection of corrosion on superheater tubes; it candidates as substitute for conventional manually operated contact UT transducers. It is the aim of the project to demonstrate the usefulness of two simple EMAT systems, Panametrics and Sonatest, for fast and reliable tube thickness inspections in difficult-to-access superheater sections. The present Phase 2 of the project involves testing of the systems on real compact superheaters in remote operation with the help of a mechanical manipulator designed and built for the purpose. The results are the following: - Both EMAT systems work well when tested in the field during handheld operation on tubes with a moderate thick layer of corrosion products and ash. The practical obtainable speed of cross-panel inspection of easily accessible panels is approximately 6 tubes per minute (6 thickness readings per minute). - The Sonatest system works well when tested in the field during remote operation on heavily corroded superheater tubes with thick ash layer. The Panametrics system was not found suitable for this type of field work. - The mechanical manipulator works well for cross-panel inspection of difficult-to-access superheater sections independent of the tube dimensions and the free space between the panels. In its present design it needs few improvements. - The practical obtainable speed of cross-panel inspection is 3 tubes per minute (3 thickness readings per minute). This speed is limited by the detection rate of the EMAT system and not by the travelling speed of the probe. - Scanning of tubes along their axis was never attempted, because the EMAT instruments were not capable of collecting data coming as a continuous stream. - It cannot be judged from visual alone and hardly from the service data, if a tube or a panel can be inspected by the magnetostrictive EMAT method or not. - The main contribution to failure of the EMAT inspection

  8. Choroidal thickness in patients with fibromyalgia and correlation with disease severity

    Directory of Open Access Journals (Sweden)

    Mahmut Oguz Ulusoy

    2018-01-01

    Full Text Available Purpose: To evaluate and compare choroidal thickness in patients with fibromyalgia (FM and healthy controls. Methods: In this prospective, cross-sectional study, forty eyes of 40 patients with FM and 40 eyes of 40 age- and sex-matched healthy subjects were enrolled. FM was diagnosed according to the American College of Rheumatology criteria. The choroidal thickness measurements of the subjects were obtained using spectral-domain optical coherence tomography (RTVue-100, Optovue. Widespread pain index (WPI, symptom severity scale (SSS, and fibromyalgia impact questionnaire (FIQ scores were recorded. The choroidal thickness measurements of the groups were compared, and correlations among the WPI, SSS, and FIQ scores and these measurements were calculated. Results: Choroidal thicknesses at 1500 μm nasally were 198.5 ± 46.7 μm and 306.3 ± 85.4 μm; at 1000 μm nasally were 211.7 ± 50.2 μm and 310.05 ± 87.26 μm; at 500 μm nasally were 216 ± 55.05 μm and 311.5 ± 83.4 μm; at subfoveal region were 230.9 ± 58.4 μm and 332.4 ± 91.3 μm; at 500 μm temporally 227.5 ± 58.1 μm and 318.15 ± 92.3 μm; at 1000 μm temporally 224.5 ± 57.07 μm and 315.1 ± 84.2 μm; at 1500 μm temporally 212.5 ± 56.08 μm and 312.9 ± 87.8 μm in the FM and control groups, respectively (P < 0.001. Choroidal thicknesses were thinner at all measurement location, except temporal 1000 and 1500 in patients with FIQ score ≥50 than in FIQ score <50. Conclusion: The results of this study demonstrated that choroidal thickness decreases in patients with FM and correlated with disease activity. This choroidal changes might be related with the alterations in autonomic nervous system functioning. Further studies are needed to evaluate the etiopathologic relationship between choroidal thickness and FM.

  9. Estimation of soft- and hard-tissue thickness at implant sites

    Directory of Open Access Journals (Sweden)

    Anil Kumar

    2014-01-01

    Full Text Available Introduction: Anchorage control is a critical consideration when planning treatment for patients with dental and skeletal malocclusions. To obtain sufficient stability of implants, the thickness of the soft tissue and the cortical-bone in the placement site must be considered; so as to provide an anatomical map in order to assist the clinician in the placement of the implants. Objective: The aim of this study is to evaluate the thickness of soft- and hard-tissue. Materials and Methods: To measure soft tissue and cortical-bone thicknesses, 12 maxillary cross-sectional specimens were obtained from the cadavers, which were made at three maxillary mid-palatal suture areas: The interdental area between the first and second premolars (Group 1, the second premolar and the first molar (Group 2, and the first and second molars (Group 3. Sectioned samples along with reference rulers were digitally scanned. Scanned images were calibrated and measurements were made with image-analysis software. We measured the thickness of soft and hard-tissues at five sectional areas parallel to the buccopalatal cementoenamel junction (CEJ line at 2-mm intervals and also thickness of soft tissue at the six landmarks including the incisive papilla (IP on the palate. The line perpendicular to the occlusal plane was made and measurement was taken at 4-mm intervals from the closest five points to IP. Results: (1 Group 1:6 mm from CEJ in buccal side and 2 mm from CEJ in palatal side. (2 Group 2:8 mm from CEJ in buccal side and 4 mm from CEJ in palatal side. (3 Group 3:8 mm from CEJ in buccal side and 8 mm from CEJ in palatal side. Conclusions: The best site for placement of implant is with thinnest soft tissue and thickest hard tissue, which is in the middle from CEJ in buccal side and closest from CEJ in palatal side in Group 1 and faraway from CEJ in buccal side and closest from CEJ in palatal side in Group 2 and faraway from CEJ in buccal side and faraway from CEJ in palatal

  10. Triaxial MEMS accelerometer with screen printed PZT thick film

    DEFF Research Database (Denmark)

    Hindrichsen, Christian Carstensen; Almind, Ninia Sejersen; Brodersen, Simon Hedegaard

    2010-01-01

    Piezoelectric thick films have increasing interest due to the potential high sensitivity and actuation force for MEMS sensors and actuators. The screen printing technique is a promising deposition technique for realizing piezoelectric thick films in the thickness range from 10-100 mu m....... In this work integration of a screen printed piezoelectric PZT thick film with silicon MEMS technology is shown. A high bandwidth triaxial accelerometer has been designed, fabricated and characterized. The voltage sensitivity is 0.31 mV/g in the vertical direction, 0.062 mV/g in the horizontal direction...... and the first mode resonance frequency is 11 kHz. A Finite Element Method (FEM) model is used to validate the measured sensitivity and resonance frequency. Good agreement between the model and the measurements is seen....

  11. Total Sediment Thickness of the World's Oceans & Marginal Seas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A digital total-sediment-thickness database for the world's oceans and marginal seas has been compiled by the NOAA National Geophysical Data Center (NGDC). The data...

  12. Accuracy of ultrasound-measured bladder wall thickness for the ...

    African Journals Online (AJOL)

    M.M. Ali

    measured urinary bladder wall thickness. (BWT) in the diagnosis of detrusor overactivity (DO). Subjects and methods: Patients who had undergone urodynamic testing due to irritative lower urinary tract symptoms (LUTS) were evaluated for ...

  13. GLERL Great Lakes Ice Thickness Data Base, 1966-1979

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During the winters of 1965/66 through 1976/77, NOAA/Great Lakes Environmental Research Laboratory (GLERL) collected weekly ice thickness and stratigraphy data at up...

  14. Mechanistic-empirical asphalt overlay thickness design and analysis system.

    Science.gov (United States)

    2009-10-01

    The placement of an asphalt overlay is the most common method used by the Texas Department of Transportation (TxDOT) to rehabilitate : existing asphalt and concrete pavements. The type of overlay and its required thickness are important decisions tha...

  15. Gridded Observational Sea Ice Thickness Products, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — Fields of long-term mean spring ice thickness derived from ERS-1 (1993-2001) and CryoSat (2011 to 2013) radar altimeters, ICESat laser altimeter (2004 to 2009),...

  16. Mapping sediment thickness of Islamabad city using empirical ...

    Indian Academy of Sciences (India)

    mail: ... is made between sediment thicknesses derived from empirical relations developed in this study with those given in literature to ... frequencies with calculated resonant frequencies (theoretical) suggests that the relation derived from the.

  17. Analysis of a Fluid-Loaded Thick Plate

    National Research Council Canada - National Science Library

    Hull, Andrew

    2002-01-01

    The physics of a thick plate with fluid loading on both sides provides the theoretical basis for insertion loss and echo reduction tests, both of which are typically used to determine how efficiently...

  18. Castings Dimensions Influence on the Alloyed Layer Thickness

    Directory of Open Access Journals (Sweden)

    Szajnar J.

    2014-03-01

    Full Text Available The paper presents the results of simulation of alloy layer formation process on the model casting. The first aim of this study was to determine the influence of the location of the heat center on alloy layer’s thickness with the use of computer simulation. The second aim of this study was to predict the thickness of the layer. For changes of technological parameters, the distribution of temperature in the model casting and temperature changes in the characteristic points of the casting were found for established changes of technological parameters. Numerical calculations were performed using programs NovaFlow&Solid. The process of obtaining the alloy layer with good quality and proper thickness depends on: pouring temperature, time of premould hold at the temperature above 1300°C. The obtained results of simulation were loaded to authorial program Preforma 1.1 in order to determine the predicted thickness of the alloy casting.

  19. Convergent beam thickness determination of thin foil zirconium specimens

    International Nuclear Information System (INIS)

    Cann, C.D.

    1978-07-01

    The use of convergent beam patterns to determine the thickness of zirconium foils observed in the electron microscope has been investigated both theoretically and experimentally. On the basis of many-beam dynamical theory calculations, the [1012], [1013], and [1120] reflections at an accelerating voltage of 100 kV and the [1013], [1120], and [1122] reflections at 200 kV were found most suitable for convergent beam thickness determinations. Experimental convergent beam patterns were obtained in the JEOL-200B electron microscope under two different sets of conditions based on the size of the pattern desired. Computer assisted analysis of the patterns obtained gave foil thicknesses in good agreement with those determined from thickness extinction contours. (author)

  20. One-cm-thick Si detector at LHe temperature

    Energy Technology Data Exchange (ETDEWEB)

    Braggio, C. [Dipartimento di Fisica, Universita di Ferrara, Via Saragat 1, 44100 Ferrara (Italy)], E-mail: braggio@pd.infn.it; Bressi, G. [INFN, Sez. di Pavia, Via Bassi 6, 27100 Pavia (Italy); Carugno, G. [INFN, Sez. di Padova, Via Marzolo 8, 35131 Padova (Italy); Galeazzi, G. [Laboratori Nazionali di Legnaro, Via dell' Universita 1, 35020 Legnaro (Italy); Serafin, A. [Dipartimento di Fisica, Universita di Padova, Via Marzolo 8, 35131 Padova (Italy)

    2007-10-11

    A silicon p-i-n diode of thickness 1 cm has been studied experimentally at liquid helium temperature. This preliminary study is aimed at the construction of a much bigger detector to detect low energy neutrino events.

  1. One-cm-thick Si detector at LHe temperature

    International Nuclear Information System (INIS)

    Braggio, C.; Bressi, G.; Carugno, G.; Galeazzi, G.; Serafin, A.

    2007-01-01

    A silicon p-i-n diode of thickness 1 cm has been studied experimentally at liquid helium temperature. This preliminary study is aimed at the construction of a much bigger detector to detect low energy neutrino events

  2. The Effect of Eggshell Thickness on Hatching Traits of Partridges

    Directory of Open Access Journals (Sweden)

    US Yamak

    Full Text Available ABSTRACT Incubation is an important factor in poultry production, particularly in species with relatively low fertility and hatchability rates. This study examined the effect of eggshell thickness on hatching traits of partridges (A. chukar. A total of 462 eggs from intensively reared partridges were separated into three groups according to eggshell thickness, which was measured ultrasonically before incubation. Hatchability, chick weight, and chick length were assessed at the end of the incubation period. Hatching times were recorded during hatching. Embryonic mortalities in unhatched eggs were classified according to mortality stage at the end of incubation. The effect of eggshell thickness on hatchability was found to be insignificant for all groups. Moreover, eggshell thickness had no significant effect on chick weight or length.

  3. optimisation of thickness of fibre reinforced polymer sheets

    African Journals Online (AJOL)

    user

    2017-01-01

    Jan 1, 2017 ... OPTIMISATION OF THICKNESS OF FIBRE REINFORCED POLYMER SHEETS FOR. STRENGTHENING REINFORCED CONCRETE BEAMS WITH FLEXURAL DEFICIENCY. J. M. Kaura. DEPARTMENT OF CIVIL ENGINEERING, AHMADU BELLO UNIVERSITY, ZARIA, KADUNA STATE. NIGERIA.

  4. Charge Distribution Dependency on Gap Thickness of CMS Endcap RPC

    CERN Document Server

    Park, Sung K.; Lee, Kyongsei

    2016-01-01

    We report a systematic study of charge distribution dependency of CMS Resistive Plate Chamber (RPC) on gap thickness. Prototypes of double-gap RPCs with six different gap thickness ranging from from 1.0 to 2.0 mm in 0.2-mm steps have been built with 2-mm-thick phenolic high-pressure-laminated plates. The efficiencies of the six gaps are measured as a function of the effective high voltages. We report that the strength of the electric fields of the gap is decreased as the gap thickness is increased. The distributions of charges in six gaps are measured. The space charge effect is seen in the charge distribution at the higher voltages. The logistic function is used to fit the charge distribution data. Smaller charges can be produced within smaller gas gap. But the digitization threshold should be also lowered to utilize these smaller charges.

  5. Determination of gold coating thickness measurement by using EDXRF

    International Nuclear Information System (INIS)

    Meor Yusoff Meor Sulaian; Masliana Muslimin; Fadlullah Jili Fursani

    2005-01-01

    The paper relates a study on the development of an analysis procedure for measuring the gold coating thickness using EDXRF technique. Gold coating thickness was measured by relating the counts under the Au L? peak its thickness value. In order to get a reasonably accurate result, a calibration graph was plotted using five gold-coated reference standards of different thickness. The calibration graph shows a straight line for thin coating measurement until 0.9 μm. Beyond this the relationship was not linear and this may be resulted from the self-absorption effect. Quantitative analysis was also performed on two different samples of gold coated jewelry and a phone connector. Result from the phone connector analysis seems to agree with the manufacturer gold coating value. From the analysis of gold-coated jewelry it had been able to differentiate the two articles as gold wash and gold electroplated. (Author)

  6. Multispectral UV imaging for determination of the tablet coating thickness

    DEFF Research Database (Denmark)

    Novikova, Anna; Carstensen, Jens Michael; Zeitler, J. Axel

    2017-01-01

    The applicability of off-line multispectral ultraviolet (UV) imaging in combination with multivariate data analysis was investigated to determine the coating thickness and its distribution on the tablet surface during lab scale coating. The UV imaging results were compared with the weight gain...... measured for each individual tablet and the corresponding coating thickness and its distribution measured by terahertz pulsed imaging (TPI). Three different tablet formulations were investigated, two of which contained UV active tablet cores. Three coating formulations were applied: Aquacoat® ECD (a mainly...... translucent coating) and Eudragit® NE (a turbid coating containing solid particles). It was shown that UV imaging is a fast and non-destructive method to predict individual tablet weight gain as well as coating thickness. The coating thickness distribution profiles determined by UV imaging correlated...

  7. Quantification of retinal layer thickness changes in acute macular neuroretinopathy

    DEFF Research Database (Denmark)

    Munk, Marion R; Beck, Marco; Kolb, Simone

    2017-01-01

    PURPOSE: To quantitatively evaluate retinal layer thickness changes in acute macular neuroretinopathy (AMN). METHODS: AMN areas were identified using near-infrared reflectance (NIR) images. Intraretinal layer segmentation using Heidelberg software was performed. The inbuilt ETDRS -grid was moved ...

  8. Benefits of the Multiple Echo Technique for Ultrasonic Thickness Testing

    Energy Technology Data Exchange (ETDEWEB)

    Elder, J.; Vandekamp, R.

    2011-02-10

    Much effort has been put into determining methods to make accurate thickness measurements, especially at elevated temperatures. An accuracy of +/- 0.001 inches is typically noted for commercial ultrasonic thickness gauges and ultrasonic thickness techniques. Codes and standards put limitations on many inspection factors including equipment, calibration tolerance and temperature variations. These factors are important and should be controlled, but unfortunately do not guarantee accurate and repeatable measurements in the field. Most technicians long for a single technique that is best for every situation, unfortunately, there are no 'silver bullets' when it comes to nondestructive testing. This paper will describe and discuss some of the major contributors to measurement error as well as some advantages and limitations of multiple echo techniques and why multiple echo techniques should be more widely utilized for ultrasonic thickness measurements.

  9. Carotid intima‑media thickness and insulin resistance changes in ...

    African Journals Online (AJOL)

    2015-09-11

    -Media Thickness (CIMT), in morbid obese patients without any known associated chronic diseases who underwent sleeve gastrectomy. Materials and Methods: The subjects of this study were patients with minimum BMI of 40, ...

  10. Carotid intima‑media thickness and insulin resistance changes in ...

    African Journals Online (AJOL)

    -Media Thickness (CIMT), in morbid obese patients without any known associated chronic diseases who underwent sleeve gastrectomy. Materials and Methods: The subjects of this study were patients with minimum BMI of 40, who did not have ...

  11. IceBridge PARIS L2 Ice Thickness V001

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains contains Greenland ice thickness measurements acquired using the Pathfinder Advanced Radar Ice Sounder (PARIS).The data were collected as part...

  12. A Finite Element Analysis of Optimal Variable Thickness Sheets

    DEFF Research Database (Denmark)

    Petersson, Joakim S

    1996-01-01

    A quasimixed Finite Element (FE) method for maximum stiffness of variablethickness sheets is analysed. The displacement is approximated with ninenode Lagrange quadrilateral elements and the thickness is approximated aselementwise constant. One is guaranteed that the FE displacement solutionswill ...

  13. Greenland 5 km DEM, Ice Thickness, and Bedrock Elevation Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — A Digital Elevation Model (DEM), ice thickness grid, and bedrock elevation grid of Greenland acquired as part of the PARCA program are available in ASCII text format...

  14. Shielding effect of a thick screen with corrugations

    OpenAIRE

    Albani, M; Piazzesi, P; Capolino, F; Maci, S; Tiberio, R

    1998-01-01

    The shielding effectiveness of a corrugated thick screen is theoretically and experimentally investigated. This screen consists of a half-plane of finite thickness in which corrugations are etched on the smaller side. This structure provides a significant attenuation in the shadow region for both polarizations of the incident field; thus, it can be effectively used for protecting apparatuses from radiating interference as well as for decoupling nearby operating antennas. The shielding propert...

  15. Prediction of UHPFRC panels thickness subjected to aircraft engine impact

    OpenAIRE

    Thai, Duc-Kien; Kim, Seung-Eock

    2016-01-01

    In the practical design of nuclear building structures subjected to an aircraft crash, the structures are required to prevent scabbing and perforation. NEI 07-13 provided the formulas to predict the minimum reinforced concrete (RC) wall thickness to prevent the local damage caused by aircraft engine impact. However, these formulas may not be suitable for predicting the thickness of the ultra-high performance fiber reinforced concrete (UHPFRC) wall. In this study, the local damage of a UHPFRC ...

  16. Effect of pre-heating composites on film thickness

    OpenAIRE

    Goulart, Marcelo; Damin, Deisi Fátima; Melara, Rafael; Conceição, Andréa de Azevedo Brito

    2013-01-01

    Resin composite has been suggested as a luting material for aesthetic indirect restorations and temperature affects material viscosity. Reports of film thickness from new composites are important. The aim of this study was to analyze the influence of pre-heating two resin composites on its film thickness in order to use it as a luting agent for indirect restorations (inlays and onlays). Three materials were divided into 5 groups. Two resin composites, nanofilled (Z350 XT/3MESPE) and microhybr...

  17. The critical thickness of liners of Cu interconnects

    International Nuclear Information System (INIS)

    Jiang, Q; Zhang, S H; Li, J C

    2004-01-01

    A model for the size-dependence of activation energy is developed. With the model and Fick's second law, relationships among the liner thickness, the working life and the working temperature of a TaN liner for Cu interconnects are predicted. The predicted results of the TaN liner are in good agreement with the experimental results. Moreover, the critical thicknesses of liners of some elements are calculated

  18. Working memory and left medial temporal cortical thickness

    OpenAIRE

    Pastura, Giuseppe; Kubo, Tadeu Takao Almodovar; Regalla, Maria Angélica; Mesquita, Cíntia Machado; Coutinho, Gabriel; Gasparetto, Emerson Leandro; Figueiredo, Otávio; Mattos, Paulo; Araújo, Alexandra Prüfer de Queiroz Campos

    2016-01-01

    ABSTRACT Objective To perform a pilot study to investigate the association between working memory and cortical thickness in a sample of attention deficit/hyperactivity disorder (ADHD) children. Methods Seventeen children aged 7-10 years diagnosed with ADHD and 16 healthy children underwent a magnetic resonance scan for cortical thickness measurements. Data was correlated with working memory performance using the Backwards Digit Span subtest of the Wechsler Intelligence Scale for Children. ...

  19. Sputtering of Thick Deuterium Films by KeV Electrons

    DEFF Research Database (Denmark)

    Thestrup Nielsen, Birgitte; Svendsen, Winnie Edith; Schou, Jørgen

    1994-01-01

    Sputtering of thick films of solid deuterium up to several μm by keV electrons is reported for the first time. The sputtering yield increases within a narrow range of thicknesses around 1.6 μm by about 2 orders of magnitude for 1.5 keV electrons. A similar behavior has not been observed for ion...... bombardment. The yield enhancement is accompanied by an increasing electron accumulation in the film....

  20. Epicardial Adipose Tissue Thickness and Ablation Outcome of Atrial Fibrillation

    Science.gov (United States)

    Tsao, Hsuan-Ming; Lin, Yenn-Jiang; Yun, Chun-Ho; Lai, Yau-Huei; Chang, Shih-Lin; Lo, Li-Wei; Hu, Yu-Feng; Tuan, Ta-Chuan; Chang, Hung-Yu; Kuo, Jen-Yuan; Yeh, Hung-I; Wu, Tsu-Juey; Hsieh, Ming-Hsiung; Yu, Wen-Chung; Chen, Shih-Ann

    2013-01-01

    Objectives Epicardial fat was closely related to atrial fibrillation (AF). Transthoracic echocardiography (TTE) has been proposed to be a convenient imaging tool in assessing epicardial adipose tissue (EAT). The goal of the present study was to investigate whether the EAT thickness measured on TTE was a useful parameter in predicting procedural outcomes of AF ablations. Methods and Results A total of 227 paroxysmal AF (PAF) and 56 non-paroxysmal AF (non-PAF) patients receiving catheter ablations from 2008-2010 were enrolled. Echocardiography-derived regional EAT thickness from parasternal long-axis view was quantified for each patient. Free of recurrence was defined as the absence of atrial arrhythmias without using antiarrhythmic agents after ablations. The mean EAT thickness of the study population was 6.1 ± 0.8 mm. Non-PAF patients had a thicker EAT than that of PAF patients (7.0 ± 0.7 mm versus 5.9 ± 0.7 mm, p value EAT thickness were independent predictors of recurrence after catheter ablations. At a cutoff value of 6 mm for PAF and 6.9 mm for non-PAF, the measurement of EAT thickness could help us to identify patients at risk of recurrences. Conclusions EAT thickness may serve as a useful parameter in predicting recurrences after AF ablations. Compared to other imaging modalities, TTE can be an alternative choice with less cost and time in assessing the effects of EAT on ablation outcomes. PMID:24066158

  1. Quantitative tectonic reconstructions of Zealandia based on crustal thickness estimates

    Science.gov (United States)

    Grobys, Jan W. G.; Gohl, Karsten; Eagles, Graeme

    2008-01-01

    Zealandia is a key piece in the plate reconstruction of Gondwana. The positions of its submarine plateaus are major constraints on the best fit and breakup involving New Zealand, Australia, Antarctica, and associated microplates. As the submarine plateaus surrounding New Zealand consist of extended and highly extended continental crust, classic plate tectonic reconstructions assuming rigid plates and narrow plate boundaries fail to reconstruct these areas correctly. However, if the early breakup history shall be reconstructed, it is crucial to consider crustal stretching in a plate-tectonic reconstruction. We present a reconstruction of the basins around New Zealand (Great South Basin, Bounty Trough, and New Caledonia Basin) based on crustal balancing, an approach that takes into account the rifting and thinning processes affecting continental crust. In a first step, we computed a crustal thickness map of Zealandia using seismic, seismological, and gravity data. The crustal thickness map shows the submarine plateaus to have a uniform crustal thickness of 20-24 km and the basins to have a thickness of 12-16 km. We assumed that a reconstruction of Zealandia should close the basins and lead to a most uniform crustal thickness. We used the standard deviation of the reconstructed crustal thickness as a measure of uniformity. The reconstruction of the Campbell Plateau area shows that the amount of extension in the Bounty Trough and the Great South Basin is far smaller than previously thought. Our results indicate that the extension of the Bounty Trough and Great South Basin occurred simultaneously.

  2. Parametric Investigation of Optimum Thermal Insulation Thickness for External Walls

    Directory of Open Access Journals (Sweden)

    Omer Kaynakli

    2011-06-01

    Full Text Available Numerous studies have estimated the optimum thickness of thermal insulation materials used in building walls for different climate conditions. The economic parameters (inflation rate, discount rate, lifetime and energy costs, the heating/cooling loads of the building, the wall structure and the properties of the insulation material all affect the optimum insulation thickness. This study focused on the investigation of these parameters that affect the optimum thermal insulation thickness for building walls. To determine the optimum thickness and payback period, an economic model based on life-cycle cost analysis was used. As a result, the optimum thermal insulation thickness increased with increasing the heating and cooling energy requirements, the lifetime of the building, the inflation rate, energy costs and thermal conductivity of insulation. However, the thickness decreased with increasing the discount rate, the insulation material cost, the total wall resistance, the coefficient of performance (COP of the cooling system and the solar radiation incident on a wall. In addition, the effects of these parameters on the total life-cycle cost, payback periods and energy savings were also investigated.

  3. Bark thickness across the angiosperms: more than just fire.

    Science.gov (United States)

    Rosell, Julieta A

    2016-07-01

    Global variation in total bark thickness (TBT) is traditionally attributed to fire. However, bark is multifunctional, as reflected by its inner living and outer dead regions, meaning that, in addition to fire protection, other factors probably contribute to TBT variation. To address how fire, climate, and plant size contribute to variation in TBT, inner bark thickness (IBT) and outer bark thickness (OBT), I sampled 640 species spanning all major angiosperm clades and 18 sites with contrasting precipitation, temperature, and fire regime. Stem size was by far the main driver of variation in thickness, with environment being less important. IBT was closely correlated with stem diameter, probably for metabolic reasons, and, controlling for size, was thicker in drier and hotter environments, even fire-free ones, probably reflecting its water and photosynthate storage role. OBT was less closely correlated with size, and was thicker in drier, seasonal sites experiencing frequent fires. IBT and OBT covaried loosely and both contributed to overall TBT variation. Thickness variation was higher within than across sites and was evolutionarily labile. Given high within-site diversity and the multiple selective factors acting on TBT, continued study of the different drivers of variation in bark thickness is crucial to understand bark ecology. © 2016 The Author. New Phytologist © 2016 New Phytologist Trust.

  4. Mid-menstrual cycle ultrasound evaluation of endometrial thickness of fertile women and women with secondary infertility in Nsukka, Nigeria

    International Nuclear Information System (INIS)

    Ochie, K.; Eze, C.U.; Okoye, G.C.; Ohagwu, C.C.; Luntsi, G.

    2016-01-01

    Background: The prognostic value of endometrial thickness in achieving conception is still debatable. Objective: To compare the mid menstrual cycle thickness of the endometrium of fertile women and women with unexplained secondary infertility. Materials and methods: A cross-sectional study targeting women of reproductive ages was conducted. The mid menstrual cycle endometrial thickness was measured at sonography in a group of fertile women and in another group of women with secondary infertility. The endometrial thicknesses in the two groups of women were statistically compared. Results: There was a preponderance of thickened endometrium among the fertile women. The majority of women with secondary infertility, 21 (30.0%) with a thickness range of 2.0–3.9 mm and 17 (24.29%) with 4.0–5.9 mm had thin endometrium and only a few of them, 8 (11.43%) had endometrium of 12 mm thickness of greater. The median value of mid menstrual cycle endometrial thickness for the fertile group was 10.8 mm (range 7.8–12.4 mm) and the interquartile range was 1.45 mm. For the group with secondary infertility, the median was 5.0 mm (range 2.0–17.0 mm) and the interquartile range 6.0 mm. The endometrium was significantly thinner in subjects with secondary infertility compared to fertile subjects (p < 0.05). Conclusion: The mid menstrual cycle endometrial thickness differs significantly between fertile women and women with secondary infertility. It is thicker in fertile women compared to women with secondary infertility. Therefore, mid menstrual cycle endometrial thickness has potential as a prognostic factor for secondary infertility in the studied population. - Highlights: • Endometrial thickness has potential as a prognostic factor for secondary infertility. • Endometrial thickness differs between fertile and secondarily infertile women. • Thin endometrium is common among women with secondary infertility. • Few women with secondary infertility may have

  5. PEDS: SOFTWARE TO ASSESS WALL THICKNESS LOSS AND WELD THICKNESS LOSS IN OFFSHORE PIPELINES THROUGH DIGITAL RADIOGRAPHY

    Directory of Open Access Journals (Sweden)

    EDMILSON MONTEIRO SOUZA

    2014-07-01

    Full Text Available A computer software to assess wall thickness loss and weld thickness loss in offshore pipelines is presented.  This software calculates the thickness loss through a data bank obtained using computational modeling based on Monte Carlo MCNPX code, and  digital radiography images obtained using image plate (BaFBr detector. In order to give users more flexibility, the computer software was written in Java, which allows it to run on Linux, Mac OS X and Windows. Tools are provided to image display, select and analyze specific areas of the image (measure average, area of selection and generate profile plots. Applications of this software in onshore and offshore inspections are presented. Preliminary results shown good agreement between real and calculated value of thickness loss.

  6. NDE of stresses in thick-walled components by ultrasonic methods

    International Nuclear Information System (INIS)

    Goebbels, K.; Pitsch, H.; Schneider, E.; Nowack, H.

    1985-01-01

    The possibilty of measuring stresses - especially residual stresses - by ultrasonic methods has been presented at the 4th and 5th International Conference on NDE in Nuclear Industry. This contribution now presents results of several applications to thick walled components such as turbines and generators for power plants. The measurement technique using linearly polarized shear waves allows one to characterize the homogeneitry of the residual stress situation along and around cylindrically shaped components. Some important results show that the stress distribution integrated over the cross section of the component has not followed in any case the simple relations derived by stress analysts. Conclusions referring to the stress situation inside the components are discussed

  7. Simple correlation equations for optimum design of annular fins with uniform thickness

    International Nuclear Information System (INIS)

    Arslanturk, Cihat

    2005-01-01

    Simple correlation equations for optimum design of annular fins with uniform cross section are obtained in the present work. The fin volume is fixed to obtain the dimensionless geometrical parameters of the fin with maximum heat transfer rates. The optimum radii ratio of an annular fin which maximizes the heat transfer rate has been found as a function of Biot number and the fin volume. The data from the present solutions is correlated for a suitable range of Biot number and the fin volume. The simple correlation equations presented in this work can assist for thermal design engineers for optimum design of annular fins of uniform thickness

  8. Neutron cross section measurements at WNR

    International Nuclear Information System (INIS)

    Lisowski, P.W.; Archampaugh, G.F.; Moore, M.S.; Morgan, G.L.; Shamu, R.E.

    1980-01-01

    The Weapons Neutron Research Facility has been used to obtain moderate-resolution total neutron cross section data for H, C, 208 Pb, 232 Th, 238 U, and 242 Pu over the energy range 5 to 200 MeV. Neutrons were produced by bombarding a 2.5-cm diam by 15-cm long Ta target with an 800 MeV pulsed proton beam from LAMPF. A 10.2-cm diam by 15.2-cm thick NE110 proton recoil detector was used at a flight path of 32 meters, giving a time-of-flight resolution of 60 ps/m. The total cross section results are compared to ENDF/BV evaluations and to previous data where possible

  9. Evaporative Water Loss in Superficial to Full Thickness Burns.

    Science.gov (United States)

    Busche, Marc Nicolai; Roettger, Anne; Herold, Christian; Vogt, Peter Maria; Rennekampff, Hans-Oliver

    2016-10-01

    Increased evaporative water loss (EWL) in burn patients leads to dehydration and hypothermia. Early clinical studies performed with outdated hygrometers suggested a 17 to 75 times increased EWL in burns with contradicting results for the different burn depths.Our study proposals were: (1) obtain reliable data of the EWL of all burn depths, (2) compare these results with findings from earlier studies, (3) evaluate the usefulness of the EWL in differentiating between superficial and deep partial thickness burns, (4) determine the effect of Biobrane on the EWL of superficial partial thickness burns in vivo, and (5) evaluate the effect of the sterile incision foil Opraflex on the EWL in split skin graft donor sites. We measured the EWL of all burn depths in 28 patients under stable and recorded conditions regarding room temperature and humidity with a modern digital evaporimeter (Tewameter TM 300). For the first time in vivo, we also determined the effect of Biobrane on the EWL of burns and evaluated the EWL in split skin graft donor sites covered with Opraflex. The EWL in all burn depths was significantly increased (P 0.05) in the EWL of superficial compared with deep partial thickness burns, whereas full thickness burns had a significantly lower EWL (P < 0.05) compared with superficial and deep partial thickness burns. Biobrane significantly reduced the EWL (P < 0.05) of superficial partial thickness burns. The EWL of Opraflex covered skin graft donor sites was significantly reduced compared with uncovered donor sites (P < 0.05). Our data suggest that the actual EWL in burns is approximately 3 times higher in full thickness burns and approximately 4 times higher in superficial and deep partial thickness burns compared with normal skin and therefore much lower than suggested previously.Because there was no significant difference in the EWL of superficial compared with deep partial thickness burns, the EWL cannot be used to differentiate between these burn depths

  10. Floodplain Cross Section Lines

    Data.gov (United States)

    Department of Homeland Security — This table is required for any Digital Flood Insurance Rate Map database where cross sections are shown on the Flood Insurance Rate Map (FIRM). Normally any FIRM...

  11. Flow Cytometry Section

    Data.gov (United States)

    Federal Laboratory Consortium — The primary goal of the Flow Cytometry Section is to provide the services of state-of-the-art multi-parameter cellular analysis and cell sorting for researchers and...

  12. Light Imaging Section

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the Light Imaging Section is to give NIAMS scientists access to state-of-the-art light imaging equipment and to offer training and assistance at all...

  13. Delivery by Cesarean Section

    Science.gov (United States)

    ... Stages Listen Español Text Size Email Print Share Delivery by Cesarean Section Page Content Article Body More ... mother has had a previous baby by Cesarean delivery The obstetrician feels that the baby’s health might ...

  14. Cell thickness of UV absorption by the cell: relation to UV action spectrum shift in mammalian cells in culture

    International Nuclear Information System (INIS)

    Sakharov, V.H.; Voronkova, L.N.; Blokhin, A.V.

    1985-01-01

    By means of reconstruction of series half - thin transverse sections the three - dimensional morphometry of SPEV cells for a series of their specific states in culture is performed: for exponential growth in a monolayer, in a merged monolayer, in the mitosis phase, for giant cells and suspension cells. In the monolayer the cell thickness in its central part depended mainly on the nucleus thickness and in average changed but slightly despite a wide range of changes in volumes of nuclei and cells and their density in culture. The cell thickness has noticeably increased in mitosis. For the above states of cells UV radiation absorption spectra are determined. It is shown that a certain shift of action spectrus of death of mammalian cells as compared with that for bacterial cell can be a seguence of selfshielding and not differences in the nature of active chromophores

  15. Residual stress measurements in thick structural weldments by means of neutron diffraction

    International Nuclear Information System (INIS)

    Ohms, C.; Youtsos, A.G.; Idsert, P. v.d.; Timke, T.

    2000-01-01

    Welding residual stresses in large structural components are a major concern with respect to their performance and lifetime. In large structures reasonable thermal stress relief treatment is usually impossible due to the component size. On the other hand, prediction of welding stresses by numerical modelling has not yet proven to be generally reliable, while the experimental determination of such stresses remains a demanding task. At the high flux reactor (HFR), Petten, a new residual stress diffractometer has been installed recently capable of handling of components up to 1000 kg - the large component neutron diffraction facility (LCNDF). It has facilitated residual stress measurements in two large welded components, of which results are presented here. The first component represents a bi-metallic weld in form of a pipe of 25 mm wall thickness. Three dimensional measurements of residual stress are discussed in detail. The second specimen is a 66 mm wall thickness austenitic steel nuclear piping weld. Results on relief of strain within the weld through post weld heat treatment (PWHT) are presented. Additionally results obtained earlier at former CRNL (CAN) on a section of a thick nuclear piping weld are presented in order to illustrate the variation in the reference lattice parameter trough the weld and the heat affected zone (HAZ). These results clearly show the necessity to determine the reference parameters for each location in all measurement directions by means of measurements in small coupons free of macro-stresses. (orig.)

  16. A thick hierarchical rutile TiO2 nanomaterial with multilayered structure

    International Nuclear Information System (INIS)

    Zhu, Shengli; Xie, Guoqiang; Yang, Xianjin; Cui, Zhenduo

    2013-01-01

    Highlights: ► We synthesized a new rutile TiO 2 nanomaterial with a hierarchical nanostructure. ► The nano architecture structure consist of nanorods and nanoflower arrays. ► The rutile TiO 2 nanomaterial is thick in size (several 10 μm). ► The TiO 2 nanomaterials present a multilayer structure. - Abstract: In the present paper, we synthesized a new type of rutile TiO 2 nanomaterial with a hierarchical nanostructure using a novel method, which combined dealloying process with chemical synthesis. The structure characters were examined using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The rutile TiO 2 nanomaterial is thick in size (several 10 μm). The hierarchical structure of the rutile TiO 2 nanomaterial consists of large quantities nanorods and nanoflower arrays. The nanoflowers consist of serveral nanopetals with diameter of 100–200 nm. The cross section of TiO 2 nanomaterials presents a multilayer structure with the layer thickness of about 3–5 μm. The rutile TiO 2 nanomaterial has high specific surface area. The formation mechanism of the rutile TiO 2 nanomaterial was discussed according to the experimental results. The rutile TiO 2 nanomaterial has potential applications in catalysis, photocatalysis and solar cells

  17. Allometry in carcasses of lambs of the Pantaneiro genetic group slaughtered with different subcutaneous fat thickness

    Directory of Open Access Journals (Sweden)

    Natália Holtz Alves Pedroso Mora

    2014-09-01

    Full Text Available Twenty-four female lambs of the Pantaneiro genetic group, with approximately 100 days of age, average body of 16.24 ± 1.78 kg, were slaughtered with 2.0, 3.0 and 4.0 mmof subcutaneous fat thickness, measured by ultrasound in the Longissimus, to evaluate the allometric growth. Lambs fed a complete pelleted diet calculated to ensure a daily weight gain of0.30 kg. Slaughtering was performed as the female lambs reached the pre-established fat thickness. After 24 hours in a cold chamber at 4ºC, chilled carcasses were cut in half and weighed. The right side was separated into five sections to determine the allometry of carcasses and cuts. Neck and rib showed isogonic growth in all treatments. Loin has remained late growth to 2.0 and3.0 mm. Shoulder and leg were isogonic growth in the treatments 3.0 and4.0 mm. The leg in relation to half carcass showed the greatest correlation. The cuts exhibited differentiated development in the growth rates of tissues. It is recommended to slaughter female lambs when they reach3.0 mm of subcutaneous fat thickness, since the carcass has already reached physiological maturity. Shoulder and leg cuts are best suited for dissection for presenting the highest correlation with the carcass in females of the Pantaneiro group.

  18. Evaluation of cortical bone thickness of mandible with cone beam computed tomography for orthodontic mini implant installation

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Moslemzade

    2014-07-01

    Full Text Available Background: Achieving maximum anchorage without movement of the teeth in anchorage unit has been a great challenge in orthodontics and the success of the treatment plan highly depends on it. In this case, using orthodontic mini-implants can make a huge difference. The objective of this retrospective study was to measure thickness of cortical bone at prospective mini-implant placement sites in mandible in order to understand stability aspects of mini-implant placement by using cone-beam computed tomography (CBCT images. Materials and Methods: Initial 3-dimensional images of 40 adult patients were studied. The cortical bone thickness was obtained at the alveolar processes from canine to second molar at 5 different vertical levels from the cementoenamel junction (CEJ. To determine the cortical bone thickness, tangent lines were drawn buccolingually to the roots in axial section and a third line was drawn from the middle of these two lines, and the cortical bone thickness was measured where the third line crossed the buccal cortex.   Results: Mandibular and buccal cortical bone thicknesses were 0.79 to 2.49 mm, respectively. There was a statistically significant increase from the CEJ to the apex (P<0.001, while this increase was not statically significant at interdental area of teeth #3 and #4. Comparing the 4 mm section in all sites showed significant increase from anterior to posterior. Conclusion: Based on our results, the cortical bone thickness mostly follows a pattern and depends on the interradicular site rather than individual differences.     Key words: Cone-beam computed tomography; orthodontic anchorage procedures

  19. Map showing thickness of saturated Quaternary deposits, Sugar House quadrangle, Salt Lake County, Utah, February 1972

    Science.gov (United States)

    Mower, R.W.

    1973-01-01

    Saturated Quaternary deposits in the Sugar Horse quadrangle supply significant quantities of water to wells from which water is withdrawn for domestic, municipal, industrial, and irrigation uses. The deposits consist of clay, silt, sand, and gravel; individual beds range from a few inches to several tens of feet thick. The principal aquifer, which is almost completely within the Quaternary deposits, supplied about 4 percent, or 9,000 acre-feet, of the municipal and industrial water used annually in Salt Lake County during 1964-68.As a general rule, more water is stored and more water will be yielded to a well where aquifers are thicker. This map can be used as a general guide to those areas where greatest amounts of water are stored in the aquifer, and where yields to wells may be greater. Local variations in the ability of saturated deposits to transmit water can alter the general relationship between aquifer thickness and yield of wells.The thickness of saturated Quaternary deposits within the area of the Sugar Horse quadrangle ranges from zero to about 650 feet, as shown on the map. The thickest section of these deposits is near the southwestern corner of the quadrangle, and the thinnest section is along the mountain front adjacent to the approximate eastern limit of saturated Quaternary deposits.The thickness of saturated Quaternary deposits shown on this map is based on drillers’ logs for 55 deep wells (which show the thickness of the Quaternary deposits) and on water-level measurements made in February 1972 in wells in unconfined shallow aquifers.Reports in the following list of selected references contain other information about the saturated Quaternary deposits in this and adjacent parts of Jordan Valley, Utah. The basic-data reports and releases contain well logs, water-level measurements, and other types of basic ground-water data. The interpretive repots contain discussions of the occurrence of ground water, tests to determine hydraulic properties of

  20. Research on the Cross Section Precision of High-strength Steel Tube with Rectangular Section in Rotary Draw Bending

    Science.gov (United States)

    Yang, Hongliang; Zhao, Hao; Xing, Zhongwen

    2017-11-01

    For the demand of energy conservation and security improvement, high-strength steel (HSS) is increasingly being used to produce safety related automotive components. However, cross-section distortion occurs easily in bending of HSS tube with rectangular section (RS), affecting the forming precision. HSS BR1500HS tube by rotary draw bending is taken as the study object and a description method of cross-section distortion is proposed in this paper. The influence on cross-section precision of geometric parameters including cross-section position, thickness of tube, bend radius etc. are studied by experiment. Besides, simulation of the rotary draw bending of HSS tube with rectangular section by ABAQUS are carried out and compared to the experiment. The results by simulation agree well with the experiment and show that the cross-section is approximately trapezoidal after distortion; the maximum of distortion exists at 45 ∼ 60° of the bending direction; and the absolute and relative distortion values increase with the decreasing of tube thickness or bending radius. Therefore, the results can provide a reference for the design of geometric parameters of HSS tube with rectangular section in rotary draw bending.