WorldWideScience

Sample records for wall thickness comparison

  1. A Comparison of American, Norwegian, and Russian Standards in Calculating the Wall Thickness of Submarine Gas Pipeline

    Directory of Open Access Journals (Sweden)

    Cindy Dianita

    2016-04-01

    Full Text Available One of the key issues in the pipeline design is wall thickness calculation. This paper highlights a comparison of wall thickness calculation methods of submarine gas pipeline based on Norwegian Standard (DNV-OS-F101, Indonesian Standard SNI 3474 which refers to American Standard(ASME B31.8, and Russian Standard (VN39-1.9-005-98. A calculation of wall thickness for a submarine gas pipeline in Indonesia (pressure 12 MPa, external diameter 668 mm gives the results of 18.2 mm (VN39-1.9-005-98, 16 mm (ASME B31.8, and 13.5 mm (DNV-OS-F101.The design formula of hoop stress due to internal pressure is interpreted in different ways for every standard. Only Norwegian Standard requires calculating hoop stresses in the inner surface, which leads to a decreased value of the wall thickness. Furthermore, the calculation of collapse factor dueto external pressure is only regulated in Americanand Norwegian Standards while Russian Standard uses that factor as an intermediate parameter in calculating local buckling. For propagation buckling, either Russian or American Standard explains empirical formula of critical hydrostatics pressure as the input in propagation buckling calculation. This formula is almost similar to the empirical formula of Norwegian Standard. From the comparison of these standards, DNV OS-F101 gives more stringent requirements than others

  2. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  3. Tube wall thickness measurement apparatus

    Science.gov (United States)

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  4. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, Paul R. (Santa Fe, NM)

    1987-01-01

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  5. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, P.R.

    1987-01-06

    An apparatus is described for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item, the apparatus comprising: a. a base; b. a first support member having first and second ends, the first end being connected to the base, the first support member having a sufficiently small circumference that the tube can be slid over the first support member; c. a spherical element, the spherical element being connected to the second end of the first support member. The spherical element has a sufficiently small circumference at its equator that the tube can be slid over the spherical element, the spherical element having at its equator a larger circumference than the first support member; d. a second support member having first and second ends, the first end being connected to the base, the second support member being spaced apart form the first support member; e. a positioning element connected to and moveable relative to the second support member; and f. an indicator connected to the positioning element and being moveable thereby to a location proximate the spherical element. The indicator includes a contact ball for contacting the selected standard item and holding it against the spherical element, the contact ball contacting the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item, the rotatable needle being operatively connected to and responsive to the position of the contact ball.

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

    African Journals Online (AJOL)

    gallbladder wall thickness and the subjects' age, sex, height and weight .... sex distributions and mean height and weights were calculated. Results were expressed .... establishing of a population-based US gallbladder wall thickness so that.

  7. Creating universes with thick walls

    CERN Document Server

    Ulvestad, Andrew

    2012-01-01

    We study the dynamics of a spherically symmetric false vacuum bubble embedded in a true vacuum region separated by a "thick wall", which is generated by a scalar field in a quartic potential. We study the "Farhi-Guth-Guven" (FGG) quantum tunneling process by constructing numerical solutions relevant to this process. The ADM mass of the spacetime is calculated, and we show that there is a lower bound that is a significant fraction of the scalar field mass. We argue that the zero mass solutions used to by some to argue against the physicality of the FGG process are artifacts of the thin wall approximation used in earlier work. We argue that the zero mass solutions should not be used to question the viability of the FGG process.

  8. Creating universes with thick walls

    Science.gov (United States)

    Ulvestad, Andrew; Albrecht, Andreas

    2012-05-01

    We study the dynamics of a spherically symmetric false vacuum bubble embedded in a true vacuum region separated by a “thick wall”, which is generated by a scalar field in a quartic potential. We study the “Farhi-Guth-Guven” (FGG) quantum tunneling process by constructing numerical solutions relevant to this process. The Arnowitt-Deser-Misner mass of the spacetime is calculated, and we show that there is a lower bound that is a significant fraction of the scalar field mass. We argue that the zero mass solutions used to by some to argue against the physicality of the FGG process are artifacts of the thin wall approximation used in earlier work. We argue that the zero mass solutions should not be used to question the viability of the FGG process.

  9. Comparison of cardiovascular magnetic resonance of late gadolinium enhancement and diastolic wall thickness to predict recovery of left ventricular function after coronary artery bypass surgery

    Directory of Open Access Journals (Sweden)

    Udompunturak Suthipol

    2008-09-01

    Full Text Available Abstract Background The objective was to compare the value of late gadolinium enhancement (LGE and end-diastolic wall thickness (EDWT assessed by cardiovascular magnetic resonance (CMR in predicting recovery of left ventricular function after coronary artery bypass surgery (CABG. Methods We enrolled patients with coronary artery disease and left ventricular ejection fraction Results We studied 46 men and 4 women with an average age of 61 years. Baseline left ventricular ejection fraction was 37 ± 13%. A total of 2,020 myocardial segments were analyzed. Abnormal wall motion and the LGE area were detected in 1,446 segments (71.6% and 1,196 segments (59.2% respectively. Wall motion improvement was demonstrated in 481 of 1,227 segments (39.2% that initially had wall motion abnormalities at baseline. Logistic regression analysis showed that the LGE area, EDWT and resting wall motion grade predicted wall motion improvement. Comparison of Receiver-Operator-Characteristic (ROC curves demonstrated that the LGE area was the most important predictor (p Conclusion LGE and EDWT are independent predictors for functional recovery after revascularization. However, LGE appears to be a more important factor and independent of EDWT.

  10. Enhanced washout of {sup 99m}Tc-tetrofosmin in hypertrophic cardiomyopathy: quantitative comparisons with regional {sup 123}I-BMIPP uptake and wall thickness determined by MRI

    Energy Technology Data Exchange (ETDEWEB)

    Thet-Thet-Lwin, Tohoru; Takeda, Jin; Wu, Yuko; Fumikura, Keiji; Iida, Satoru; Kawano, Iwao; Yamaguchi, Yuji; Itai [Institute of Clinical Medicine, University of Tsukuba, Tennodai 1-1-1, 305-8575, Tsukuba-shi, Ibaraki-ken (Japan)

    2003-07-01

    The diagnostic value of technetium-99m tetrofosmin (TF) washout in hypertrophic cardiomyopathy (HCM) was examined by investigating its relation to the metabolic abnormality depicted by iodine-123 {beta}-methyl-p-iodophenylpentadecanoic acid (BMIPP) uptake and the left ventricular (LV) myocardial wall thickness as measured by magnetic resonance imaging (MRI). TF washout was evaluated in 31 patients with HCM and 23 normal control subjects using 30-min (early) and 3-h (delayed) TF single-photon emission tomography images. The LV myocardial wall was divided into 19 segments and the percentage TF washout, regional BMIPP uptake and LV wall thickness were measured in each segment. Mean TF washout in the patients with HCM was significantly faster than that in normal control subjects (23.7{+-}5.7 vs 13.4{+-}4.1, P<0.0001). In the patients with HCM, TF washout showed an excellent correlation with MRI wall thickness (r=0.82, P<0.0001) and a good inverse correlation with regional BMIPP uptake (r=-0.72, P<0.0001). In addition, a good linear correlation was observed between TF uptake and MRI wall thickness in the 19 regional segments. In conclusion, the degree of TF washout corresponds well with the severity of myocardial wall thickness and the degree of metabolic abnormality in patients with HCM. These results suggest that enhanced TF washout might provide additional clinical information regarding metabolic alterations in HCM. (orig.)

  11. 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.

  12. Weekly doxorubicin increases coronary arteriolar wall and adventitial thickness.

    Directory of Open Access Journals (Sweden)

    Delrae M Eckman

    Full Text Available BACKGROUND: Doxorubicin (DOX is associated with premature cardiovascular events including myocardial infarction. This study was performed to determine if the weekly administration of DOX influenced coronary arteriolar medial and/or adventitial wall thickening. METHODS: Thirty-two male Sprague-Dawley rats aged 25.1± 2.4 weeks were randomly divided into three groups and received weekly intraperitoneal injections of normal saline (saline, n = 7, or low (1.5 mg/kg to 1.75 mg/kg, n = 14 or high (2.5 mg/kg, n = 11 doses of DOX. The animals were treated for 2-12 weeks, and euthanized at pre-specified intervals (2, 4, 7, or 10+ weeks to obtain histopathologic assessments of coronary arteriolar lumen diameter, medial wall thickness, adventitial wall thickness, and total wall thickness (medial thickness + adventitial thickness. RESULTS: Lumen diameter was similar across all groups (saline: 315±34 µm, low DOX: 286±24 µm, high DOX: 242±27 µm; p = 0.22. In comparison to animals receiving weekly saline, animals receiving weekly injections of 2.5 mg/kg of DOX experienced an increase in medial (23±2 µm vs. 13±3 µm; p = 0.005, and total wall thickness (51±4 µm vs. 36±5 µm; p = 0.022, respectively. These increases, as well as adventitial thickening became more prominent after normalizing for lumen diameter (p<0.05 to p<0.001 and after adjusting for age, weight, and total cumulative DOX dose (p = 0.02 to p = 0.01. Animals receiving low dose DOX trended toward increases in adventitial and total wall thickness after normalization to lumen diameter and accounting for age, weight, and total cumulative DOX dose (p = 0.06 and 0.09, respectively. CONCLUSION: In conclusion, these data demonstrate that weekly treatment of rats with higher doses of DOX increases coronary arteriolar medial, adventitial, and total wall thickness. Future studies are warranted to determine if DOX related coronary arteriolar effects are

  13. EFFECT OF WALL THICKNESS ON THE SOLAR GAIN

    Directory of Open Access Journals (Sweden)

    KEREKES A.

    2016-03-01

    Full Text Available Utilized passive solar gain covers considerable part of heat losses, especially in well insulated buildings. At the same time the thermal insulation of the wall in such a building, e.g. approaching the “Passivhaus” standard is about 20 cm thick. Unless a light weight building is spoken of further 20-30 cm loadbearing layer and the surface finishing should be added resulting in a total thickness of 45-60 cm. The thick wall narrows the cross section through which the direct solar beam may enter the room thus decreases the solar gain. The movement of the solar beam during the day and season can be followed on the base of the sun path diagram. One could say that on the other hand a massive loadbearing layer - especially if it is on the inner side - increases the heat storage capacity, thus increases the utilized part of the solar gain. Series of thermal simulation proves that the effect of heat storage capacity is less important in comparison with the cross section through which the solar beam enters the room. In other terms a light weight building with thin walls performs better than a massive one with thick wall providing the U-value is the same in both cases. In this paper the results of simulation will be presented. Certainly the wall should fulfill many requirements including load, weather-proofness, thermal insulation, building technology. Solar beam is only one of the many aspects. Nevertheless simple geometric tricks may lead to a good compromise, e.g. bevel edge reveal which is not perpendicular to the façade. No doubt in this case the thermal bridge losses around the window perimeter will be higher however this will be compensated by the solar gain.

  14. Three-dimensional collapse and steady flow in thick-walled flexible tubes

    Science.gov (United States)

    Marzo, A.; Luo, X. Y.; Bertram, C. D.

    2005-08-01

    Three-dimensional collapse of and steady flow through finite-length elastic tubes are studied numerically. The Navier-Stokes equations coupled with large, nonlinear deformation of the elastic wall are solved by using the finite-element software, FIDAP. Three-dimensional solid elements are used for the elastic wall, allowing us to specify any wall thickness required. Plane-strain results for the cross-sectional shape of thinner-walled tubes are validated by comparison with published numerical data. Three-dimensional results for flow through finite-thickness tubes are in excellent agreement with published numerical results based on thin-shell elements, and are used to show the effects of varying wall thickness. Finally, the computational predictions are compared with experimental pressure area relationships for thick-walled tubes. The simulations confirm a previously neglected experimental finding, that the Young wavespeed can be lower between buckling and osculation for thick tubes than for thinner ones.

  15. Mortality by Level of Emphysema and Airway Wall Thickness

    DEFF Research Database (Denmark)

    Johannessen, Ane; Skorge, Trude Duelien; Bottai, Matteo;

    2013-01-01

    There is limited knowledge of the prognostic value of quantitative computed tomography (CT) measures of emphysema and airway wall thickness (AWT) on mortality.......There is limited knowledge of the prognostic value of quantitative computed tomography (CT) measures of emphysema and airway wall thickness (AWT) on mortality....

  16. Evaluation of Tube Wall Thickness of Feed Water Heater

    Science.gov (United States)

    Uchikura, Takahisa; Morisaki, Koichi; Hamada, Seiichi

    With regard to the high pressure (HP) feed water heater of thermal power plant at Tokyo Electric Power Company (TEPCO) sites, inspection of feed water (FW) tubes wall thickness are conducted whenever required such that frequent tube leak occurs. As a standard inspection methodology, FW heater is disassembled during planned outage, tube wall thickness is measured by the ultrasonic pulse techique (UT), then plugs are installed at the both ends of FW tube if its measured wall thickness is found below calculated threshold. However, the root causes of wall thinning of FW tube are various such as erosion and corrosion, based on wall thinning condition, the above threshold is not applied but utilizing the other technically well-grounded evaluation method is sometimes more rational. Therefore, TEPCO classified wall-thinning condition based on inspection data and established technically well-grounded and rational evaluation methodologies of FW tube wall thickness to suite each wall thinning condition. Moreover, with recent improvement of inspection technique, technology enabled faster, larger amount, and more accurate data acquisition, TEPCO has developed the systematized evaluation methodology that can transact data acquisition and evaluation simultaneously. This article introduces the logic of evaluation methods and examined algorithms to make them systematized.

  17. 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.

  18. Thick domain wall spacetimes with and without reflection symmetry

    CERN Document Server

    Melfo, A; Skirzewski, A; Melfo, Alejandra; Pantoja, Nelson; Skirzewski, Aureliano

    2003-01-01

    We show that the spacetimes of domain wall solutions to the coupled Einstein-scalar field equations with a given scalar field potential fall into two classes, depending on whether or not reflection symmetry on the wall is imposed. Solutions with reflection symmetry are dynamic, while the asymmetric ones are static. Asymmetric walls are asymptotically flat on one side and reduce to the Taub spacetime on the other. Examples of asymmetric thick walls in D-dimensional spacetimes are given, and results on the thin-wall limit of the dynamic, symmetric walls are extended to the asymmetric case. The particular case of symmetric, static spacetimes is considered and a new family of solutions, including previously known BPS walls, is presented.

  19. Evolution of thick domain walls in de Sitter universe

    CERN Document Server

    Dolgov, A D; Rudenko, A S

    2016-01-01

    We consider thick domain walls in a de Sitter universe following paper by Basu and Vilenkin. However, we are interested not only in stationary solutions found therein, but also investigate the general case of domain wall evolution with time. When the wall thickness parameter, $\\delta_0$, is smaller than $H^{-1}/\\sqrt{2}$, where $H$ is the Hubble parameter in de Sitter space-time, then the stationary solutions exist, and initial field configurations tend with time to the stationary ones. However, there are no stationary solutions for $\\delta_0 \\geq H^{-1}/\\sqrt{2}$. We have calculated numerically the rate of the wall expansion in this case and have found that the width of the wall grows exponentially fast for $\\delta_0 \\gg H^{-1}$. An explanation for the critical value $\\delta_{0c} = H^{-1}/\\sqrt{2}$ is also proposed.

  20. Evolution of thick domain walls in de Sitter universe

    Science.gov (United States)

    Dolgov, A. D.; Godunov, S. I.; Rudenko, A. S.

    2016-10-01

    We consider thick domain walls in a de Sitter universe following paper by Basu and Vilenkin. However, we are interested not only in stationary solutions found therein, but also investigate the general case of domain wall evolution with time. When the wall thickness parameter, δ0, is smaller than H‑1/√2, where H is the Hubble parameter in de Sitter space-time, then the stationary solutions exist, and initial field configurations tend with time to the stationary ones. However, there are no stationary solutions for δ0 >= H‑1/√2. We have calculated numerically the rate of the wall expansion in this case and have found that the width of the wall grows exponentially fast for δ0 gg H‑1. An explanation for the critical value δ0c = H‑1/√2 is also proposed.

  1. Occlusion-free Blood Flow Animation with Wall Thickness Visualization.

    Science.gov (United States)

    Lawonn, Kai; Glaßer, Sylvia; Vilanova, Anna; Preim, Bernhard; Isenberg, Tobias

    2016-01-01

    We present the first visualization tool that combines pathlines from blood flow and wall thickness information. Our method uses illustrative techniques to provide occlusion-free visualization of the flow. We thus offer medical researchers an effective visual analysis tool for aneurysm treatment risk assessment. Such aneurysms bear a high risk of rupture and significant treatment-related risks. Therefore, to get a fully informed decision it is essential to both investigate the vessel morphology and the hemodynamic data. Ongoing research emphasizes the importance of analyzing the wall thickness in risk assessment. Our combination of blood flow visualization and wall thickness representation is a significant improvement for the exploration and analysis of aneurysms. As all presented information is spatially intertwined, occlusion problems occur. We solve these occlusion problems by dynamic cutaway surfaces. We combine this approach with a glyph-based blood flow representation and a visual mapping of wall thickness onto the vessel surface. We developed a GPU-based implementation of our visualizations which facilitates wall thickness analysis through real-time rendering and flexible interactive data exploration mechanisms. We designed our techniques in collaboration with domain experts, and we provide details about the evaluation of the technique and tool.

  2. Polarizabilities of an Annular Cut in the Thick Wall.

    Science.gov (United States)

    Kurennoy, Sergey S.

    1996-05-01

    The electric and magnetic polarizabilities of an aperture are its important characteristics used in the theory of aperture coupling and diffraction of EM waves. The polarizabilities of the aperture having a form of a ring-shaped cut in the plane wall of an arbitrary thickness are calculated by solving corresponding electrostatic or magnetostatic problems using a combination of analytical, variational and numerical methods. The dependences of the polarizabilities on the aperture parameters and on the wall thickness are presented. The results are applied to estimate the beam coupling impedances of button-type beam position monitors.

  3. Combined Visualization of Wall Thickness and Wall Shear Stress for the Evaluation of Aneurysms.

    Science.gov (United States)

    Glaßer, Sylvia; Lawonn, Kai; Hoffmann, Thomas; Skalej, Martin; Preim, Bernhard

    2014-12-01

    For an individual rupture risk assessment of aneurysms, the aneurysm's wall morphology and hemodynamics provide valuable information. Hemodynamic information is usually extracted via computational fluid dynamic (CFD) simulation on a previously extracted 3D aneurysm surface mesh or directly measured with 4D phase-contrast magnetic resonance imaging. In contrast, a noninvasive imaging technique that depicts the aneurysm wall in vivo is still not available. Our approach comprises an experiment, where intravascular ultrasound (IVUS) is employed to probe a dissected saccular aneurysm phantom, which we modeled from a porcine kidney artery. Then, we extracted a 3D surface mesh to gain the vessel wall thickness and hemodynamic information from a CFD simulation. Building on this, we developed a framework that depicts the inner and outer aneurysm wall with dedicated information about local thickness via distance ribbons. For both walls, a shading is adapted such that the inner wall as well as its distance to the outer wall is always perceivable. The exploration of the wall is further improved by combining it with hemodynamic information from the CFD simulation. Hence, the visual analysis comprises a brushing and linking concept for individual highlighting of pathologic areas. Also, a surface clustering is integrated to provide an automatic division of different aneurysm parts combined with a risk score depending on wall thickness and hemodynamic information. In general, our approach can be employed for vessel visualization purposes where an inner and outer wall has to be adequately represented.

  4. Evaluation of Average Wall Thickness of Organically Modified Mesoporous Silica

    Institute of Scientific and Technical Information of China (English)

    Yan Jun GONG; Zhi Hong LI; Bao Zhong DONG

    2005-01-01

    The small angle X-ray scattering of organically modified MSU-X silica prepared by co-condensation of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) show negative deviation from Debye's theory due to the existence of the organic interface layer. By exerting correction of the scattering negative deviation, Debye relation may be recovered, and the average wall thickness of the material may be evaluated.

  5. Development of thick wall welding and cutting tools for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Nakahira, Masataka; Takahashi, Hiroyuki; Akou, Kentaro; Koizumi, Koichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-04-01

    The Vacuum Vessel, which is a core component of International Thermonuclear Experimental Reactor (ITER), is required to be exchanged remotely in a case of accident such as superconducting coil failure. The in-vessel components such as blanket and divertor are planned to be exchanged or fixed. In these exchange or maintenance operations, the thick wall welding and cutting are inevitable and remote handling tools are necessary. The thick wall welding and cutting tools for blanket are under developing in the ITER R and D program. The design requirement is to weld or cut the stainless steel of 70 mm thickness in the narrow space. Tungsten inert gas (TIG) arc welding, plasma cutting and iodine laser welding/cutting are selected as primary option. Element welding and cutting tests, design of small tools to satisfy space requirement, test fabrication and performance tests were performed. This paper reports the tool design and overview of welding and cutting tests. (author)

  6. Noninvasive Stiffness Sensing of Ventricular Wall Based on a Thick-walled Cylinder Model

    Science.gov (United States)

    Higashimori, Mitsuru; Ojio, Takeshi; Takeda, Yasuharu; Sakata, Yasushi; Yamamoto, Kazuhiro; Kaneko, Makoto

    This paper discusses a concept of a noninvasive sensing method that can estimate a left ventricular wall stiffness towards a medical diagnosis. Focusing on not only the strain of ventricular wall but also the displacements of epicardium during diastole of heart beat, we propose an index of ventricular wall stiffness based on a thick-walled cylinder model. Applying the proposed method to the echocardiography, we show statistical results where normal and HFpEF (Heart Failure with preserved Ejection Fraction) can be separated towards a medical diagnosis.

  7. Ultrasound settings significantly alter arterial lumen and wall thickness measurements

    Directory of Open Access Journals (Sweden)

    Green Daniel J

    2008-01-01

    Full Text Available Abstract Background Flow-mediated dilation (FMD and carotid intima-medial thickness (CIMT, measured by ultrasound, are widely used to test the efficacy of cardioprotective interventions. Although assessment methods vary, automated edge-detecting image analysis software is routinely used to measure changes in FMD and CIMT. We aimed to quantify the effect that commonly adjusted ultrasound settings have on arterial lumen and wall thickness measurements made with CIMT measurement software. Methods We constructed phantom arteries from a tissue-mimicking agar compound and scanned them in a water bath with a 10 MHz multi-frequency linear-array probe attached to a high-resolution ultrasound machine. B-mode images of the phantoms were recorded with dynamic range (DR and gain set at five decibel (dB increments from 40 dB to 60 dB and -10 dB to +10 dB respectively. Lumen diameter and wall-thickness were measured off-line using CIMT measurement software. Results Lumen measurements: there was a strong linear relationship between DR and gain and measured lumen diameter. For a given gain level, a 5 dB increase in DR reduced the measured lumen diameter by 0.02 ± 0.004 mm (p CIMT measurements: For a fixed gain level, a 5 dB increase in DR increased measured wall thickness by 0.003 ± 0.002 mm (p Conclusion DR, gain and probe distance significantly alter lumen diameter and CIMT measurements made using image analysis software. When CIMT and FMD are used to test the efficacy of cardioprotective interventions, the DR, gain and probe position used to record baseline scans should be documented and replicated in post-treatment scans in individual trial subjects. If more than one sonographer or imaging centre is used to collect data, the study protocol should document specific DR and gain settings to be used in all subjects.

  8. Shape optimization of a thick-walled power boiler component

    Directory of Open Access Journals (Sweden)

    Duda Piotr

    2017-01-01

    Full Text Available This paper presents a methodology and successful application of structural optimization of a T-pipe under transient thermal and mechanical loads. In order to find the optimal shape of a thick-walled power boiler component, a parametric FE model and the evolutionary algorithm (EA are applied. The power boiler start-up and shutdown curves are based on the TRD 301 guidelines. Maximum total stresses are assumed as optimization constraints. The obtained geometry is by about 18.6% lighter than the original one due to thinning of the walls. Maximum tensile and compressive stresses in the modified geometry are smaller than in the original one during the whole cycle. Additionally, lower total stress values are recorded during heating and cooling processes. Therefore, these transient processes can be accelerated and the shutdown and start-up losses can be reduced.

  9. Velocity Field and Variation of Wall Thickness During Tube Dieless Upsetting

    Institute of Scientific and Technical Information of China (English)

    王忠堂; 栾瑰馥; 张士宏

    2004-01-01

    Theoretical analyses show that the variation of wall thickness is in direct proportion to outer-diameter, inter-diameter, and (√1 + Rs) (Rs is sectional increase ratio of tube), the theoretical calculated results of wall thickness during tube dieless upsetting are very approximate to the experimental one. As the width of deformation field increases, both the variation of wall thickness and the derivative of wall thickness variation to width of deformation field (tf/to) reduce.

  10. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Nominal wall thickness (t) for steel pipe. 192.109... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Pipe Design § 192.109 Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not known...

  11. 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).

  12. Effect of wall thickness and helium cooling channels on duct magnetohydrodynamic flows

    Energy Technology Data Exchange (ETDEWEB)

    He, Qingyun; Feng, Jingchao; Chen, Hongli, E-mail: hlchen1@ustc.edu.cn

    2016-02-15

    Highlights: • MHD flows in ducts of different wall thickness compared with wall uniform. • Study of velocity, pressure distribution in ducts MHD flows with single pass of helium cooling channels. • Comparison of three types of dual helium cooling channels and acquisition of an option for minimum pressure drop. • A single short duct MHD flow in blanket without FCI has been simulated for pressure gradient analysis. - Abstract: The concept of dual coolant liquid metal (LM) blanket has been proposed in different countries to demonstrate the technical feasibility of DEMO reactor. In the system, helium gas and PbLi eutectic, separated by structure grid, are used to cool main structure materials and to be self-cooled, respectively. The non-uniform wall thickness of structure materials gives rise to wall non-homogeneous conductance ratio. It will lead to electric current distribution changes, resulting in significant changes in the velocity distribution and pressure drop of magnetohydrodynamic (MHD) flows. In order to investigate the effect of helium channels on MHD flows, different methods of numerical simulations cases are carried out including the cases of different wall thicknesses, single pass of helium cooling channels, and three types of dual helium cooling channels. The results showed that helium tubes are able to affect the velocity distribution in the boundary layer by forming wave sharp which transfers from Hartmann boundary layer to the core area. In addition, the potential profile and pressure drop in the cases have been compared to these in the case of walls without cooling channel, and the pressure gradient of a simplified single short duct MHD flow in blanket shows small waver along the central axis in the helium channel position.

  13. Thick Liquid-Walled, Field-Reversed Configuration

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R W; Bulmer, R H; Gulec, K; Fogarty, P; Nelson, B; Ohnishi, M; Rensink, M; Rognlien, T D; Santarious, J F; Sze, D K

    2000-09-22

    A thick flowing layer of liquid (e.g., flibe--a molten salt, or Sn{sub 80}Li{sub 20}--a liquid metal) protects the structural walls of the field-reversed configuration (FRC) so that they can last the life of the plant even with intense 14 MeV neutron bombardment from the D-T fusion reaction. The surface temperature of the liquid rises as it passes from the inlet nozzles to the exit or receiver nozzles due to absorption of line and bremsstrahlung radiation, and neutrons. The surface temperature can be reduced by enhancement of convection near the surface to transport hot surface liquid into the cooler interior. This surface temperature must be compatible with a practical heat transport and energy recovery system. The evaporative flux from the wall driven by the surface temperature must also result in an acceptable impurity level in the core plasma. The shielding of the core by the edge plasma is modeled with a 2D transport code for the resulting impurity ions; these ions are either swept out to the distant end tanks, or diffuse to the hot plasma core. An auxiliary plasma between the edge plasma and the liquid wall can further attenuate evaporating flux of atoms and molecules by ionization. The current in this auxiliary plasma might serve as the antenna for the current drive method, which produces a rotating magnetic field. Another method of current drive uses small spheromaks injected along the magnetic fields, which additionally provide fueling along with pellet fueling if necessary.

  14. All- Ceramic Crown Preparation and the Remained wall Thickness of the Pulp Chamber

    Directory of Open Access Journals (Sweden)

    Mohammadzadeh Akhlaghi N.

    2012-12-01

    Full Text Available tatement of Problem: A minimally invasive method of preparation is essential to prevent tooth structure weakening and pulp irritation; especially for mandibular anterior single-tooth all-ceramic crowns. According to many investigations, one of the most important reasons of pulp injury caused by tooth preparation for different restorative procedures is reduced “remained wall thickness” (RWT. In order to protect the pulp from irritation, it is necessary to maintain a 0.5 mm of RWT.Purpose: The purpose of the present study was to evaluate the effect of all-ceramic crown preparation on pulp chamber RWT of mandibular incisors.Materials and Method: Mesiodistal and buccolingual initial images of 24 ex-tracted mandibular incisors were provided. The pulp chamber initial wall thick-nesses of buccal, lingual and proximal surfaces of cervical, 1and 2 mm above the cervical areas and also the incisal surfaces of incisal sections were measured using digital radiography and Photoshop software. After all-ceramic crown preparation, images were provided at the same initial positions. The initial and remained pulp chamber wall thicknesses were statistically evaluated and analyzed by ANOVA, paired t-test and a post hoc Tukey test.Results: Repeated measures ANOVA showed that the mean of pre- or post-preparation wall thicknesses were not significantly different for each surface at the three horizontal levels (p> 0.05. However, there were significant differences between the surfaces for each section. Comparison of pre- and post-preparation wall thicknesses revealed significant differences (p< 0.05. Proximal surfaces of cervical sections had the least RWT (0.42±0.12.Conclusion: According to the results of the present study, the least amount of initial and remained wall thicknesses of pulp chamber were related to the proximal surfaces, particularly in cervical areas. Therefore a reduction of preparation to 0.7 mm is suggested to prevent future pulp injury for

  15. Exact solution of eddy current losses produced by a domain wall with nonzero thickness

    Energy Technology Data Exchange (ETDEWEB)

    Real, R.P. del [Laboratorio de Optoelectronica, Area de Cargas Utiles e Instrumentacion, Departamento de Ciencias del Espacio y Tecnologias Electronicas, Instituto Nacional de Tecnica Aeroespacial (INTA), Torrejon de Ardoz 28850 (Spain)]. E-mail: perezrr@inta.es

    2006-08-15

    The influence of the domain wall thickness on eddy current losses has been calculated. It is shown that, for samples with low magnetic anisotropy and small thickness, the reduction of magnetic losses with respect to the zero thickness domain wall must be seriously taken into account.

  16. Effect of Mould Wall Thickness on Rate of Solidification of Centrifugal Casting

    Directory of Open Access Journals (Sweden)

    Madhusudhan

    2010-11-01

    Full Text Available In Centrifugal Casting process the centrifugal force presses the metal against the inner wall of the metal mould, resulting in rapid solidification of the molten metal. However the solidification structures like structural uniformity and structural character of the solidified metal of centrifugal casting is of great importance, regarding to its mechanical properties. The solidification time of the casting is dependent upon the various parameters like speed ofrotation of the mold, mould wall temperature, heat transfer coefficient at the metal-mold interface, mould wall thickness, material of the mould and so on. In this paper experimental study of effect of mould wall thickness on solidification of the centrifugal casting has been discussed. As the mould wall thickness increases, due to the chilling effect, the solidification time decreases. Fine grains are observed in castings produced in thick walled mould and coarse grains are observed in thin walled moulds. Brinel Hardness of the casting was measured.

  17. Wall thickness variation effect on tank’s shape behaviour under critical harmonic settlement

    Directory of Open Access Journals (Sweden)

    Ahmed Shamel Fahmy

    2016-12-01

    Full Text Available The purpose of this study was to investigate the effect of wall thickness variation on tank’s wall buckling mode under the effect of critical harmonic settlement for open top tanks. The study was performed on four tanks which have the same geometric and material properties except wall thickness, for each case the tank was subjected to several settlement waves which has the same settlement amplitude, and the buckling mode and critical vertical settlement results were compared. For buckling mode, the results show that tanks with wall thickness at a close range have similar buckling mode behaviour and in case using too thick wall the buckling mode starts to change. And for the effect on critical vertical settlement, the results show that vertical settlement is sensitive to any variation in wall thickness beside that settlement value changes with the effected wave number and this variation could change the whole behaviour of the tanks. The study recommended that in case of performing analysis for a tank with neglecting the variation in wall thickness values, the value of chosen wall thickness should be the average of wall thickness values obtained from the designed equation.

  18. Quantitative computed tomography measures of emphysema and airway wall thickness are related to respiratory symptoms

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Dirksen, Asger; Coxson, Harvey O

    2010-01-01

    There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness.......There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness....

  19. Quantitative computed tomography measures of emphysema and airway wall thickness are related to respiratory symptoms

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Dirksen, Asger; Coxson, Harvey O

    2010-01-01

    There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness.......There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness....

  20. Fluid-Structure Simulations of a Ruptured Intracranial Aneurysm: Constant versus Patient-Specific Wall Thickness.

    Science.gov (United States)

    Voß, S; Glaßer, S; Hoffmann, T; Beuing, O; Weigand, S; Jachau, K; Preim, B; Thévenin, D; Janiga, G; Berg, P

    2016-01-01

    Computational Fluid Dynamics is intensively used to deepen the understanding of aneurysm growth and rupture in order to support physicians during therapy planning. However, numerous studies considering only the hemodynamics within the vessel lumen found no satisfactory criteria for rupture risk assessment. To improve available simulation models, the rigid vessel wall assumption has been discarded in this work and patient-specific wall thickness is considered within the simulation. For this purpose, a ruptured intracranial aneurysm was prepared ex vivo, followed by the acquisition of local wall thickness using μCT. The segmented inner and outer vessel surfaces served as solid domain for the fluid-structure interaction (FSI) simulation. To compare wall stress distributions within the aneurysm wall and at the rupture site, FSI computations are repeated in a virtual model using a constant wall thickness approach. Although the wall stresses obtained by the two approaches-when averaged over the complete aneurysm sac-are in very good agreement, strong differences occur in their distribution. Accounting for the real wall thickness distribution, the rupture site exhibits much higher stress values compared to the configuration with constant wall thickness. The study reveals the importance of geometry reconstruction and accurate description of wall thickness in FSI simulations.

  1. Revisited the mathematical derivation wall thickness measurement of pipe for radiography

    Energy Technology Data Exchange (ETDEWEB)

    Hamzah, A.R.; Amir, S.M.M. [Non Destructive Testing(NDT) Group, Industrial Technology Div., Malaysian Nuclear Agency, Selangor (Malaysia)

    2007-07-01

    Wall thickness measurement of pipe is very important of the structural integrity of the industrial plant. However, the radiography method has an advantage because the ability of penetrating the insulated pipe. This will have economic benefit for industry. Moreover, the era of digital radiography has more advantages because the speed of radiographic work, less exposure time and no chemical used for film development. Either the conventional radiography or digital radiology, the wall thickness measurement is using the tangential radiography technique (TRT). In case, of a large diameter, pipe (more than inches) the determination maximum penetration wall thickness must be taken into the consideration. This paper is revisited the mathematical derivation of the determination of wall thickness measurement based on tangential radiography technique (TRT). The mathematical approach used in this derivation is the Pythagoras theorem and geometrical principles. In order to derive the maximum penetration wall thickness a similar approach is used. (authors)

  2. Effects of Antimony and Wall Thickness on Graphite Morphology in Ductile Iron Castings

    Science.gov (United States)

    Glavas, Zoran; Strkalj, Anita; Maldini, Kresimir

    2016-08-01

    Effects of Sb additions on the graphite morphology of ductile iron castings in different wall thicknesses (3, 12, 25, 38, 50, 75, and 100 mm) were analyzed in this paper. In the wall thicknesses of 3, 12, and 25 mm, low contents of rare earth (RE) elements showed a beneficial effect on nodule count and nodularity. Nodularity >80 pct and a high nodule count were achieved without the addition of Sb. In the wall thicknesses of 38, 50, 75, and 100 mm, nodularity >80 pct was not achieved without the use of the chill or proper content of Sb. Excess of RE elements was neutralized with the addition of proper amount of Sb to the wall thickness. Addition of 0.01 wt pct Sb (ratio of RE/Sb = 0.34, ratio of RE/SE = 0.105) was sufficient to achieve nodularity >80 pct in the wall thicknesses of 38, 50, 75, and 100 mm.

  3. A hybrid method for airway segmentation and automated measurement of bronchial wall thickness on CT.

    Science.gov (United States)

    Xu, Ziyue; Bagci, Ulas; Foster, Brent; Mansoor, Awais; Udupa, Jayaram K; Mollura, Daniel J

    2015-08-01

    Inflammatory and infectious lung diseases commonly involve bronchial airway structures and morphology, and these abnormalities are often analyzed non-invasively through high resolution computed tomography (CT) scans. Assessing airway wall surfaces and the lumen are of great importance for diagnosing pulmonary diseases. However, obtaining high accuracy from a complete 3-D airway tree structure can be quite challenging. The airway tree structure has spiculated shapes with multiple branches and bifurcation points as opposed to solid single organ or tumor segmentation tasks in other applications, hence, it is complex for manual segmentation as compared with other tasks. For computerized methods, a fundamental challenge in airway tree segmentation is the highly variable intensity levels in the lumen area, which often causes a segmentation method to leak into adjacent lung parenchyma through blurred airway walls or soft boundaries. Moreover, outer wall definition can be difficult due to similar intensities of the airway walls and nearby structures such as vessels. In this paper, we propose a computational framework to accurately quantify airways through (i) a novel hybrid approach for precise segmentation of the lumen, and (ii) two novel methods (a spatially constrained Markov random walk method (pseudo 3-D) and a relative fuzzy connectedness method (3-D)) to estimate the airway wall thickness. We evaluate the performance of our proposed methods in comparison with mostly used algorithms using human chest CT images. Our results demonstrate that, on publicly available data sets and using standard evaluation criteria, the proposed airway segmentation method is accurate and efficient as compared with the state-of-the-art methods, and the airway wall estimation algorithms identified the inner and outer airway surfaces more accurately than the most widely applied methods, namely full width at half maximum and phase congruency.

  4. A pilot study on bladder wall thickness at different filling stages

    Science.gov (United States)

    Zhang, Xi; Liu, Yang; Li, Baojuan; Zhang, Guopeng; Liang, Zhengrong; Lu, Hongbing

    2015-03-01

    The ever-growing death rate and the high recurrence of bladder cancer make the early detection and appropriate followup procedure of bladder cancer attract more attention. Compare to optical cystoscopy, image-based studies have revealed its potentials in non-invasive observations of the abnormities of bladder recently, in which MR imaging turns out to be a better choice for bladder evaluation due to its non-ionizing and high contrast between urine and wall tissue. Recent studies indicate that bladder wall thickness tends to be a good indicator for detecting bladder wall abnormalities. However, it is difficult to quantitatively compare wall thickness of the same subject at different filling stages or among different subjects. In order to explore thickness variations at different bladder filling stages, in this study, we preliminarily investigate the relationship between bladder wall thickness and bladder volume based on a MRI database composed of 40 datasets acquired from 10 subjects at different filling stages, using a pipeline for thickness measurement and analysis proposed in our previous work. The Student's t-test indicated that there was no significant different on wall thickness between the male group and the female group. The Pearson correlation analysis result indicated that negative correlation with a correlation coefficient of -0.8517 existed between the wall thickness and bladder volume, and the correlation was significant(p score of wall thickness would be more appropriate to reflect the thickness variations. For possible abnormality detection of a bladder based on wall thickness, the intra-subject and inter-subject thickness variation should be considered.

  5. Analysis of Thick-Walled Cylinder Temperature Field based on the Thermal-Fluid-Solid Coupling

    Directory of Open Access Journals (Sweden)

    Yonghai Wu

    2013-04-01

    Full Text Available The barrel is a special thick-walled cylinder. It is significance to study the temperature distribution of thick-walled cylinder under liquid-cooled state to weapon launch safety and effectiveness. Taking a naval gun barrel as research objective, a unified thermal-fluid-solid coupling model is put forward including barrel solid wall, the cooling water and the water jacket solid wall. The unsteady coupled temperature field of the barrel is calculated at the time of single and continuous firing and some influencing factors such as cooling water flow velocity, barrel wall thickness and so on, are analyzed to the barrel temperature field. The results show that the water cooling effect of the barrel outer is closely related to the wall thickness and the cooling water flow velocity. When the barrel wall thickness is small, increasing the flow velocity increase heat dissipation and reduce barrel wall temperature obviously. When the barrel wall thickness is large, the water cooling effect depends on the total cooling time and small correlation with the velocity of cooling water flow.

  6. On the linear dependence of a carbon nanofiber thermal conductivity on wall thickness

    Directory of Open Access Journals (Sweden)

    Alexandros Askounis

    2016-11-01

    Full Text Available Thermal transport in carbon nanofibers (CNFs was thoroughly investigated. In particular, individual CNFs were suspended on T-type heat nanosensors and their thermal conductivity was measured over a range of temperatures. Unexpectedly, thermal conductivity was found to be dependent on CNF wall thickness and ranging between ca. 28 and 43 W/(m⋅K. Further investigation of the CNF walls with high resolution electron microscopy allowed us to propose a tentative description of how wall structure affects phonon heat transport inside CNFs. The lower thermal conductivities, compared to other CNTs, was attributed to unique CNF wall structure. Additionally, wall thickness is related to the conducting lattice length of each constituent graphene cone and comparable to the Umklapp length. Hence, as the wall thickness and thus lattice length increases there is a higher probability for phonon scattering to the next layer.

  7. An analytical method for calculating stresses and strains of ATF cladding based on thick walled theory

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Hyun; Kim, Hak Sung [Hanyang University, Seoul (Korea, Republic of); Kim, Hyo Chan; Yang, Yong Sik; In, Wang kee [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this paper, an analytical method based on thick walled theory has been studied to calculate stress and strain of ATF cladding. In order to prescribe boundary conditions of the analytical method, two algorithms were employed which are called subroutine 'Cladf' and 'Couple' of FRACAS, respectively. To evaluate the developed method, equivalent model using finite element method was established and stress components of the method were compared with those of equivalent FE model. One of promising ATF concepts is the coated cladding, which take advantages such as high melting point, a high neutron economy, and low tritium permeation rate. To evaluate the mechanical behavior and performance of the coated cladding, we need to develop the specified model to simulate the ATF behaviors in the reactor. In particular, the model for simulation of stress and strain for the coated cladding should be developed because the previous model, which is 'FRACAS', is for one body model. The FRACAS module employs the analytical method based on thin walled theory. According to thin-walled theory, radial stress is defined as zero but this assumption is not suitable for ATF cladding because value of the radial stress is not negligible in the case of ATF cladding. Recently, a structural model for multi-layered ceramic cylinders based on thick-walled theory was developed. Also, FE-based numerical simulation such as BISON has been developed to evaluate fuel performance. An analytical method that calculates stress components of ATF cladding was developed in this study. Thick-walled theory was used to derive equations for calculating stress and strain. To solve for these equations, boundary and loading conditions were obtained by subroutine 'Cladf' and 'Couple' and applied to the analytical method. To evaluate the developed method, equivalent FE model was established and its results were compared to those of analytical model. Based on the

  8. The Bulging Behavior of Thick-Walled 6063 Aluminum Alloy Tubes Under Double-Sided Pressures

    Science.gov (United States)

    Cui, Xiao-Lei; Wang, Xiao-Song; Yuan, Shi-Jian

    2015-05-01

    To make further exploration on the deformation behavior of tube under double-sided pressures, the thick-walled 6063 aluminum alloy tubes with an outer diameter of 65 mm and an average thickness of 7.86 mm have been used to be bulged under the combined action of internal and external pressures. In the experiment, two ends of the thick-walled tubes were fixed using the tooth and groove match. Three levels of external pressure (0 MPa, 40 MPa, and 80 MPa), in conjunction with the internal pressure, were applied on the tube outside and inside simultaneously. The effect of external pressure on the bulging behavior of the thick-walled tubes, such as the limiting expansion ratio, the bulging zone profile, and the thickness distribution, has been investigated. It is shown that the limiting expansion ratio, the bulging zone profile, and the thickness distribution in the homogeneous bulging area are all insensitive to the external pressure. However, the external pressure can make the thick-walled tube achieve a thinner wall at the fracture area. It reveals that the external pressure can only improve the fracture limit of the thick-walled 6063 tubes, but it has very little effect on their homogeneous bulging behavior. It might be because the external pressure can only increase the magnitude of the hydrostatic pressure for the tube but has no effect on the Lode parameter.

  9. Domain walls in Fe(001) bicrystals-thickness dependence and field-induced transitions

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, M. [Department of Applied physics, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)]. E-mail: maj.hanson@fy.chalmers.se; Brucas, R. [Department of Applied physics, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)

    2007-03-15

    Magnetic domain walls (DW's) formed at the grain boundary (GB) of epitaxial bicrystal Fe(001) films, thickness t=50 and 70nm, were studied by magnetic force microscopy. The 'as-grown' samples displayed DW's with different magnetic contrast profiles yielding a single peak for t=50nm and a double peak with a change of sign at the centre of the wall for t=70nm. For t=50nm the wall is characterised as an asymmetric Bloch wall. The double peak of the 70nm thick film transformed into a single peak characteristic for a charged wall, when a field of 30mT was applied along the GB. At remanence this domain wall relaxed to a regular Bloch wall divided into segments of alternating signs.

  10. MRI-based Determination of Reference Values of Thoracic Aortic Wall Thickness in a General Population

    Energy Technology Data Exchange (ETDEWEB)

    Mensel, Birger; Quadrat, Alexander; Schneider, Tobias; Kuehn, Jens-Peter; Hegenscheid, Katrin [University Medicine Greifswald, Institute of Diagnostic Radiology and Neuroradiology, Greifswald (Germany); Doerr, Marcus [University Medicine Greifswald, Department of Internal Medicine, Greifswald (Germany); DZHK (German Center for Cardiovascular Research), Greifswald (Germany); Voelzke, Henry [University Medicine Greifswald, Institute for Community Medicine, Greifswald (Germany); DZHK (German Center for Cardiovascular Research), Greifswald (Germany); Lieb, Wolfgang [Christian Albrechts University, Institute of Epidemiology, Kiel (Germany); Lorbeer, Roberto [University Medicine Greifswald, Institute for Community Medicine, Greifswald (Germany)

    2014-09-15

    To provide age- and sex-specific reference values for MRI-derived wall thickness of the ascending and descending aorta in the general population. Data of 753 subjects (311 females) aged 21-81 years were analysed. MRI was used to determine the aortic wall thickness (AWT). Equations for reference value calculation according to age were established for females and males. Median wall thickness of the ascending aorta was 1.46 mm (5th-95th range: 1.15-1.88 mm) for females and 1.56 mm (1.22-1.99 mm) for males. Median wall thickness of the descending aorta was 1.26 mm (0.97-1.58 mm) in females and 1.36 mm (1.04-1.75 mm) in males. While median and 5th and 95th percentiles for the ascending and descending aorta increased with age in both sexes, the association between age and median AWT was stronger in males than in females for both the ascending and descending aorta. Reference values for the ascending and descending AWT are provided. In a healthy sample from the general population, the wall of the ascending aorta is thicker than the wall of the descending aorta, and both walls are thicker in males than females. The increase in wall thickness with age is greater in males. (orig.)

  11. Reconstruction of massive full-thickness abdominal wall defect

    DEFF Research Database (Denmark)

    Aydin, Dogu; Paulsen, Ida Felbo; Bentzen, Vibeke Egerup

    2016-01-01

    We demonstrate that it is possible to use a nonabsorbable mesh for abdominal wall reconstruction after total wound rupture and successfully split-skin graft directly on the mesh. Sufficient granulation tissue formation prior to skin grafting was obtained with long-term use of negative pressure...

  12. Impact of exercise training on arterial wall thickness in humans.

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Cable, N.T.; Green, D.J.

    2012-01-01

    Thickening of the carotid artery wall has been adopted as a surrogate marker of pre-clinical atherosclerosis, which is strongly related to increased cardiovascular risk. The cardioprotective effects of exercise training, including direct effects on vascular function and lumen dimension, have been co

  13. Space-resolved Resistive Measurement of Liquid Metal Wall Thickness

    CERN Document Server

    Mirhoseini, S M H

    2016-01-01

    In a fusion reactor internally coated with liquid metal, it will be important to diagnose the thickness of the liquid at various locations in the vessel, as a function of time, and possibly respond to counteract undesired bulging or depletion. The electrical conductance between electrodes immersed in the liquid metal can be used as a simple proxy for the local thickness. Here a matrix of electrodes is shown to provide spatially resolved measurements of liquid metal thickness in the absence of plasma. First a theory is developed for mxn electrodes, and then it is experimentally demonstrated for 3x1 electrodes. The experiments were carried out with Galinstan, but are easily extended to Lithium or other liquid metals.

  14. Thermal variations of domain wall thickness and number of domains in magnetic rectangular grains

    Science.gov (United States)

    Xu, Song; Merrill, Ronald T.

    1990-12-01

    Equilibrium domain wall thickness and number of domains in rectangular magnetic grains are determined by using a modified Amar model. It is shown that domain structure, particularly domain wall thickness, in a magnetized grain depends strongly on grain shape and orientation. These dependencies are attributed to the existence of two competing self-magnetostatic interactions, one from the ends of the grain and the other from the sides. One of the consequences of this is that the thermal variation of domain wall thickness in an elongated grain is greater (smaller) than predicted by classical theory when the grain is magnetized along the shortest (longest) dimension. For magnetite, classical theory provides a good approximation in predicting both domain wall thickness and number of domains in equal-dimensional grains larger than about 4 μm.

  15. Reconstruction of full thickness abdominal wall defect following tumor resection: A case report

    Directory of Open Access Journals (Sweden)

    Kovačević Predrag

    2014-01-01

    Full Text Available Introduction. Reconstruction of a full thickness abdominal wall defect is a demanding procedure for general and also for plastic surgeons, requiring vigorous planning and reconstruction of three layers. Case Outline. We present a case of a 70-year-old patient with a huge abdominal wall tumor with 40 years evolution. Surgery was performed under general anesthesia. Full thickness abdominal defect appeared after the tumor resection. Reconstruction followed in the same act. The defect was reconstructed using a combination of techniques, including omental flap, fascia lata graft, local skin flaps and skin grafts. After surgery no major complications were noted, only a partial skin flap loss, which was repaired using partial thickness skin grafts. The final result was described by the patient as very good, without hernia formation. Conclusion. Omenthoplasty, abdominal wall reconstruction in combination with free fascia lata graft and skin grafts can be one of good options for the reconstruction of full thickness abdominal wall defects.

  16. Quantitative CT measures of emphysema and airway wall thickness are related to D(L)CO

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Thorsen, Einar; Dirksen, Asger

    2011-01-01

    There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness.......There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness....

  17. Quantitative CT measures of emphysema and airway wall thickness are related to D(L)CO

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Thorsen, Einar; Dirksen, Asger;

    2011-01-01

    There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness.......There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness....

  18. Control on mine pressure of thick and strong roof stratum movement in long wall thick coal caving face

    Institute of Scientific and Technical Information of China (English)

    DENG Guang-zhe; ZHANG dian-chang; HE Tao

    2008-01-01

    The caving of thick and strong roof stratum causes tremendous rock pressurein mine. The results of the analysis on dynamic natures of actual measurements of somefields, of which the roof pressure can be caused by thick and strong stratum in long wallthick coal caving face, could present the relation between the collapse and movement ofthick and strong roof strata and surrounding rock pressure. In order to control the roofpressure effectively, the thick and strong roof strata, can be fractured and softened previ-ously by hydraulic fracturing and low-high pressure water infusion, fracturing and softeningmethod. The results of study can provide basis for strata control and safe management inlong wall thick coal caving face.

  19. Study of Individual Characteristic Abdominal Wall Thickness Based on Magnetic Anchored Surgical Instruments

    Institute of Scientific and Technical Information of China (English)

    Ding-Hui Dong; Wen-Yan Liu; Hai-Bo Feng; Yi-Li Fu; Shi Huang; Jun-Xi Xiang; Yi Lyu

    2015-01-01

    Background:Magnetic anchored surgical instruments (MASI),relying on magnetic force,can break through the limitations of the single port approach in dexterity.Individual characteristic abdominal wall thickness (ICAWT) deeply influences magnetic force that determines the safety of MASI.The purpose of this study was to research the abdominal wall characteristics in MASI applied environment to find ICAWT,and then construct an artful method to predict ICAWT,resulting in better safety and feasibility for MASI.Methods:For MASI,ICAWT is referred to the thickness of thickest point in the applied environment.We determined ICAWT through finding the thickest point in computed tomography scans.We also investigated the traits of abdominal wall thickness to discover the factor that can be used to predict ICAWT.Results:Abdominal wall at C point in the middle third lumbar vertebra plane (L3) is the thickest during chosen points.Fat layer thickness plays a more important role in abdominal wall thickness than muscle layer thickness."BMI-ICAWT" curve was obtained based on abdominal wall thickness of C point in L3 plane,and the expression was as follow:f(x) =P1 × x2 + P2 x x + P3,where P1 =0.03916 (0.01776,0.06056),P2 =1.098 (0.03197,2.164),P3 =-18.52 (-31.64,-5.412),R-square:0.99.Conclusions:Abdominal wall thickness of C point at L3 could be regarded as ICAWT.BMI could be a reliable predictor of ICAWT.In the light of "BMI-ICAWT" curve,we may conveniently predict ICAWT by BMI,resulting a better safety and feasibility for MASI.

  20. Study of Individual Characteristic Abdominal Wall Thickness Based on Magnetic Anchored Surgical Instruments

    Directory of Open Access Journals (Sweden)

    Ding-Hui Dong

    2015-01-01

    Full Text Available Background: Magnetic anchored surgical instruments (MASI, relying on magnetic force, can break through the limitations of the single port approach in dexterity. Individual characteristic abdominal wall thickness (ICAWT deeply influences magnetic force that determines the safety of MASI. The purpose of this study was to research the abdominal wall characteristics in MASI applied environment to find ICAWT, and then construct an artful method to predict ICAWT, resulting in better safety and feasibility for MASI. Methods: For MASI, ICAWT is referred to the thickness of thickest point in the applied environment. We determined ICAWT through finding the thickest point in computed tomography scans. We also investigated the traits of abdominal wall thickness to discover the factor that can be used to predict ICAWT. Results: Abdominal wall at C point in the middle third lumbar vertebra plane (L3 is the thickest during chosen points. Fat layer thickness plays a more important role in abdominal wall thickness than muscle layer thickness. "BMI-ICAWT" curve was obtained based on abdominal wall thickness of C point in L3 plane, and the expression was as follow: f(x = P1 × x 2 + P2 × x + P3, where P1 = 0.03916 (0.01776, 0.06056, P2 = 1.098 (0.03197, 2.164, P3 = −18.52 (−31.64, −5.412, R-square: 0.99. Conclusions: Abdominal wall thickness of C point at L3 could be regarded as ICAWT. BMI could be a reliable predictor of ICAWT. In the light of "BMI-ICAWT" curve, we may conveniently predict ICAWT by BMI, resulting a better safety and feasibility for MASI.

  1. Comparison between multi-detector row CT angiography and Doppler ultrasound on detecting carotid artery wall thickness%多层螺旋CT与Doppler超声对颈动脉壁层厚度的对比性研究

    Institute of Scientific and Technical Information of China (English)

    赵刚; 查云飞; 王弘; 洪玮; 邱晓明; 王珍; 肖友梅

    2013-01-01

    Objective To explore the relationship and consistency between multi-detector row computed tomography angiography (MDCTA) and color Doppler ultrasound (CD-US) in measuring carotid artery wall thickness (CAWT) and intima-media thickness (IMT). Methods CAWT and IMT of 38 subjects were measured using MDCTA and CD-US, respectively. Linear correlation analysis was performed to analyze the correlation between the results from CAWT and IMT,and Bland-Altman statistics was employed to analyze the consistency between them. Results The IMT value measured by CD-US was (0.85+0.16) mm, and the CAWT value measured by MDCTA was (0.87.± 0.18) mm (P > 0.05), and there was a high degree of correlation between them (correlation coefficient was 0.958,P< 0.01). An excellent consistency between CAWT and IMT was found by Bland-Altman plot, with a bias of 0.026 mm and the limit of consistency from -0.023 to 0.075. Conclusions There were significant correlation and consistency between MDCTA and CD-US in detecting CAWT and IMT. As a more objective and comprehensive new method, MDCTA can replace CD-US in the evaluation of early carotid atherosclerosis.%目的:探讨多层螺旋CT血管造影(MDCTA)和彩色多普勒超声(CD-US)在检测颈总动脉壁厚度(CAWT)和颈总动脉内膜-中层厚度(IMT)中的相关性和一致性.方法:应用MDCTA和CD-US分别对38例受试者颈总动脉的CAWT和IMT进行检测,用Pearson直线相关分析比较CAWT和IMT的相关性,用Bland-Altman分析比较两者的一致性.结果:MDCTA测量的颈总动脉CAWT为(0.87±0.18)mm,CD-US测量的颈总动脉IMT为(0.85±0.16)mm,两者比较无统计学差异,有高度相关性,相关系数为0.958,P<0.01,Bland-Altman分析两者间存在良好一致性,偏倚为0.026 mm,一致性界限为-0.023 ~ 0.075.结论:MDCTA和CD-US在检测颈总动脉CAWT和IMT时存在良好的相关性和一致性,MDCTA可以替代CD-US,作为一种评价颈动脉早期粥样硬化的更加客观全面的新方法.

  2. Method for Improving Transverse Wall Thickness Precision of Seamless Steel Tube Based on Tube Rotation

    Institute of Scientific and Technical Information of China (English)

    Yong-zheng JIANG; Hua-ping TANG

    2015-01-01

    The tube rotation method (TRM) refers to the rotational movement of steel tube about its axis as well as translation in rolling direction in stretch reducing rolling process. The inlfuence of the TRM on transverse wall thickness precision of seamless steel tube was studied. Thickness distribution of the TRM was obtained by superimposing the thickened amount of single pass roll-ing. Results show that the TRM can effectively improve the evenness of thickness distribution. In order to analyze the inlfuence mechanism of the TRM, the ifnite element method was adopted to simulate the thickness distribution in stretch reduction process. Results show that the TRM changes the roundtrip lfow between two ifx places of conventional stretch reducing and inhibits the directional accumulation of metal. In addition, the TRM has a correction effect on thickness cusp. All these advantages of the TRM help to improve the transverse wall thickness precision of seamless steel tube.

  3. Multimodal optical measurement in vitro of surface deformations and wall thickness of the pressurized aortic arch.

    Science.gov (United States)

    Genovese, Katia; Humphrey, Jay D

    2015-04-01

    Computational modeling of arterial mechanics continues to progress, even to the point of allowing the study of complex regions such as the aortic arch. Nevertheless, most prior studies assign homogeneous and isotropic material properties and constant wall thickness even when implementing patient-specific luminal geometries obtained from medical imaging. These assumptions are not due to computational limitations, but rather to the lack of spatially dense sets of experimental data that describe regional variations in mechanical properties and wall thickness in such complex arterial regions. In this work, we addressed technical challenges associated with in vitro measurement of overall geometry, full-field surface deformations, and regional wall thickness of the porcine aortic arch in its native anatomical configuration. Specifically, we combined two digital image correlation-based approaches, standard and panoramic, to track surface geometry and finite deformations during pressurization, with a 360-deg fringe projection system to contour the outer and inner geometry. The latter provided, for the first time, information on heterogeneous distributions of wall thickness of the arch and associated branches in the unloaded state. Results showed that mechanical responses vary significantly with orientation and location (e.g., less extensible in the circumferential direction and with increasing distance from the heart) and that the arch exhibits a nearly linear increase in pressure-induced strain up to 40%, consistent with other findings on proximal porcine aortas. Thickness measurements revealed strong regional differences, thus emphasizing the need to include nonuniform thicknesses in theoretical and computational studies of complex arterial geometries.

  4. WEIGHT FUNCTION FOR STRESS INTENSITY FACTORS IN ROTATING THICK-WALLED CYLINDER

    Institute of Scientific and Technical Information of China (English)

    CHEN Ai-jun; ZENG Wen-ji

    2006-01-01

    The equation of stress intensity factors(SIF) of internally pressurized thickwalled cylinder was used as the reference case. SIF equation of rotating thick-walled cylinder containing a radial crack along the internal bore was presented in weight function method. The weight function formulas were worked out and can be used for all kinds of depth of cracks, rotating speed, material, size of thick-walled cylinder to calculate the stress intensity factors. The results indicated the validity and effectiveness of these formulas. Meanwhile, the rules of the stress intensity factors in rotating thick-walled cylinder with the change of crack depths and the ratio of outer radius to inner radius were studied. The studies are valuable to engineering application.

  5. [Effect of wall thickness of left ventricle on 201Tl myocardial SPECT images: myocardial phantom study].

    Science.gov (United States)

    Koto, M; Namura, H; Kawase, O; Yamasaki, K; Kono, M

    1996-07-01

    201Tl myocardial SPECT is known for better sensitivity, specificity, and accuracy than planar images in detecting coronary artery disease and diagnosing myocardial viability. SPECT images are also superior to planar images in diagnostic sensitivity and anatomical orientation. However, as limitation of the spatial resolution of the machine, we often encounter poor SPECT plower image quality in patients with decreased wall thickness. To test the accuracy of SPECT images in patients with marked thinning of the left ventricular wall, as occurs in dilated cardiomyopathy, we performed a experimental study using myocardial phantom with 7 mm wall thickness. Tomographic image of the phantom images were rather heterogeneous, though no artificial defect was located. Dilated cardiomyopathy is thought to be characterized by patchy defects in the left ventricle. Careful attention should be given to elucidating myocardial perfusion in patients with a thin left ventricle wall, as there are technical limitations in addition to clinical features.

  6. Micromagnetic simulation of thickness variation of Neel cap in hybrid Bloch-Neel domain wall

    Energy Technology Data Exchange (ETDEWEB)

    Lu Mai [Key Lab. of Opto-Electronic Technology and Intelligent Control, Lanzhou Jiaotong University, Ministry of Education, P.O. Box 73, 118 West Anning Road, Lanzhou 730070, Gansu (China) and Department of Signals and Systems, Chalmers University of Technology, SE-412 96, Gothenburg (Sweden)]. E-mail: m.lu@mail.edu.cn; Leonard, Paul J. [Department of Electronic and Electrical Engineering, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2005-08-01

    The hybrid Bloch-Neel domain wall in iron film has been investigated using three-dimensional micromagnetic calculations. Magnetization distributions in the film plane and cross-section are presented. In the film plane the rotation of magnetization in the 180 deg domain wall takes two different patterns from the bottom layer to the top layer. In cross-section the C-shaped magnetization distribution with hybrid Bloch-Neel domain wall has been found. The thickness of the top Neel cap changes from its largest value as the C-shaped magnetization distribution appears, and becomes thinner as the C-shaped magnetization distribution gradually moves and grows up. The thickness variation of the bottom Neel cap changes in a similar way, but with a reversal pattern. The results in this paper will enrich our knowledge of magnetic domain and domain wall patterns in magnetic materials.

  7. Colonic wall thickness measured by ultrasound: striking differences in patients with cystic fibrosis versus healthy controls.

    OpenAIRE

    1997-01-01

    BACKGROUND: Colonic strictures represent an advanced stage of fibrosing colonopathy in patients with cystic fibrosis. AIMS: To clarify whether ultrasonography can identify patients with an early stage of fibrosing colonopathy and to determine clinical factors that influence bowel wall thickening. PATIENTS: Ninety patients with cystic fibrosis, median age 10 years, and 46 healthy controls, median age 13 years, were investigated. METHODS: Bowel wall thickness was measured by ultrasound in a pro...

  8. Room temperature synthesis of indium tin oxide nanotubes with high precision wall thickness by electroless deposition

    OpenAIRE

    Mario Boehme; Emanuel Ionescu; Ganhua Fu; Wolfgang Ensinger

    2011-01-01

    Conductive nanotubes consisting of indium tin oxide (ITO) were fabricated by electroless deposition using ion track etched polycarbonate templates. To produce nanotubes (NTs) with thin walls and small surface roughness, the tubes were generated by a multi-step procedure under aqueous conditions. The approach reported below yields open end nanotubes with well defined outer diameter and wall thickness. In the past, zinc oxide films were mostly preferred and were synthesized using electroless de...

  9. Influences of Randomly Distributed Wall THickness of Beverage Can on Its Strength and Stiffness

    Institute of Scientific and Technical Information of China (English)

    XuJing-jing; WANGZhi-ling; 等

    2001-01-01

    This paper describes the research undertaken on the strength and stiffness of fluctuation on the wall thickness of steel beverage cans using the Monte-Carlo stochastic finite element method.Sample distributions were firestly assumed and then proven using the data observations of the wall thickness.the APDL language was then applied,and the stresses and displacements of the can were calculated by using the ANSYS software.It is concluded that the structureal reliability of a steel-making beverage can be estimated accurately.

  10. Design on curves of wall-thickness for Blow Molding Machine based on HMI

    Directory of Open Access Journals (Sweden)

    Cheng Yayun

    2015-01-01

    Full Text Available Properly control of blow molding machine’s wall-thickness relates to the quality of plastic products,design on curves is the key technology of blow molding machine’s wall-thickness control.Adopted cubic spline curve as a fitting prototype,used advanced HMI as a design platform,by cooperation with HMI configuration function and macro code,an interface of curves was designed,a good performance of human-computer interaction and core data’s transmission in the whole machine were realized.By using this method,the integration of the system was increased and costs was reduced dramatically.

  11. Thickness measuring of electroconductive pipe walls using the dual-frequency eddy-current method

    Science.gov (United States)

    Yakimov, Evgeny; Galtseva, Olga; Ustyugov, Daniil

    2017-01-01

    The paper describes a dual-frequency method for reducing the impact of changes in the gap size between the eddy-current transducer and the pipe, as well as the pipe electrical conductivity on the eddy-current thickness gauge readings. A block-diagram of the dual-frequency eddy-current thickness gauge is proposed for light-alloy drill pipes. The amplitude and signal phase dependencies on the wall thickness in the range from 6 to 17 mm and the gap in the range from 0 to 13.5 mm were studied, the results are presented. The digital signal processing algorithms based on the piecewise-linear approximation of low-frequency and high-frequency signal phase dependencies on the wall thickness are proposed. It is shown that the proposed correction algorithms can reduce the error caused by variations of electrical conductivity and the gap between the transducer and the pipe.

  12. Unsteady natural convection in an anisotropic porous medium sandwiched between finite thickness walls

    Energy Technology Data Exchange (ETDEWEB)

    Harzallah, H.S.; Zegnani, A.; Slimi, K.; Mhimid, A. [Ecole Nationale D' Ingenieurs de Monastir, Monastir (Tunisia)

    2009-07-01

    Natural convection through anisotropic porous media is of significant interest in a wide variety of applications such as in geophysics, hydrology, oil extraction, and reservoir engineering. Anisotropy is basically a consequence of a preferential orientation and/or asymmetric geometry of the grains or fibres. Despite its broad range of applications, natural problems involving anisotropic effects in the presence of porous materials coupled with the effect of the bounding walls have received relatively little attention. This paper examined the effects of both thermal and mechanical anisotropies, as well as the effect of the conductive walls on the unsteady heat transfer and fluid flow through a porous material sandwiched between two vertical finite thickness walls maintained at constant but different temperatures. The remaining two horizontal walls were thermally insulated. The influencing non-dimensional parameters governing heat and fluid flow in the presented system were the wall thickness, wall-to-porous medium thermal conductivity ratio, wall-to-porous medium heat capacity ratio, anisotropic thermal conductivity ratio and anisotropic permeability ratio according to x-axis, and Rayleigh number. The purpose of the study was to demonstrate the effects of heat conduction within solid boundaries as well as both thermal and mechanical anisotropies on flow and heat transfer rates. It was concluded that as the anisotropic thermal conductivity ratio along the x-axis increases, the conductive mode becomes stronger than the convective one. 13 refs., 7 figs.

  13. Performance Comparison of Thin and Thick Film Microstrip Rejection Filters

    OpenAIRE

    Mandhare, M. M.; S.A. Gangal; M. S. Setty; Karekar, R. N.

    1988-01-01

    A performance comparison of microstripline circuits using thin and thick film techniques has been studied, in which a Microstrip rejection filter, in the X-band of microwaves, is used as test circuit. A thick film technique is capable of giving good adhesive films with comparable d.c. sheet resistivity, but other parameters such as open area (porosity), particle size, and edge definition are inferior to thin-film microstrip filters. Despite this drawback, the average value of transmission, tr...

  14. Quantitative CT: Associations between Emphysema, Airway Wall Thickness and Body Composition in COPD

    DEFF Research Database (Denmark)

    Rutten, Erica P A; Grydeland, Thomas B; Pillai, Sreekumar G

    2011-01-01

    The objective of the present study was to determine the association between CT phenotypes-emphysema by low attenuation area and bronchitis by airway wall thickness-and body composition parameters in a large cohort of subjects with and without COPD. In 452 COPD subjects and 459 subjects without COPD...

  15. Discrimination of Cylinders with Different Wall Thicknesses using Neural Networks and Simulated Dolphin Sonar Signals

    DEFF Research Database (Denmark)

    Andersen, Lars Nonboe; Au, Whitlow; Larsen, Jan;

    1999-01-01

    This paper describes a method integrating neural networks into a system for recognizing underwater objects. The system is based on a combination of simulated dolphin sonar signals, simulated auditory filters and artificial neural networks. The system is tested on a cylinder wall thickness...

  16. Magnet Fall inside a Conductive Pipe: Motion and the Role of the Pipe Wall Thickness

    Science.gov (United States)

    Donoso, G.; Ladera, C. L.; Martin, P.

    2009-01-01

    Theoretical models and experimental results are presented for the retarded fall of a strong magnet inside a vertical conductive non-magnetic tube. Predictions and experimental results are in good agreement modelling the magnet as a simple magnetic dipole. The effect of varying the pipe wall thickness on the retarding magnetic drag is studied for…

  17. Endoluminal compression clip : full-thickness resection of the mesenteric bowel wall in a porcine model

    NARCIS (Netherlands)

    Kopelman, Yael; Siersema, Peter D.; Nir, Yael; Szold, Amir; Bapaye, Amol; Segol, Ori; Willenz, Ehud P.; Lelcuk, Shlomo; Geller, Alexander; Kopelman, Doron

    2009-01-01

    Background: Performing a full-thickness intestinal wall resection Of a sessile polyp located on the mesenteric side with a compression clip may lead to compression of mesenteric vessels. The application of such a clip may therefore cause a compromised blood supply in the particular bowel segment, le

  18. Quantitative computed tomography: emphysema and airway wall thickness by sex, age and smoking

    DEFF Research Database (Denmark)

    Grydeland, T B; Dirksen, A; Coxson, H O;

    2009-01-01

    We investigated how quantitative high-resolution computed tomography (HRCT) measures of emphysema and airway wall thickness (AWT) vary with sex, age and smoking history. We included 463 chronic obstructive pulmonary disease (COPD) cases and 431 controls. All included subjects were current or ex...

  19. The influence of clinical and genetic factors on left ventricular wall thickness in Ragdoll cats.

    Science.gov (United States)

    Borgeat, Kieran; Stern, Joshua; Meurs, Kathryn M; Fuentes, Virginia Luis; Connolly, David J

    2015-12-01

    To investigate the effect of various genetic and environmental modifiers on left ventricular (LV) wall thickness in a cohort of cats genotyped for the myosin binding protein C3 mutation (MYBPC3). Sixty-four Ragdoll cats. All cats were screened for HCM with echocardiography and genotyping for the HCM-associated MYBPC3:R820W mutation. Cats were also genotyped for previously identified variant polymorphisms of the angiotensin-converting enzyme (ACE) and cardiac beta-adrenergic receptor (ADRB1) genes. Plasma N-terminal pro-B-type natriuretic peptide and cardiac troponin I were also measured. Associations were evaluated between genotype (MYBPC3 negative/positive, and ACE and ADRB1 negative/heterozygous/homozygous), patient factors (body weight, age and sex) and echocardiographic measurements of LV wall thickness. Male cats had greater maximum wall thickness (LVmax; 5.8 mm, IQR 5.1-6.4 mm) than females (4.7 mm, IQR 4.4-5.3 mm, p = 0.002). Body weight positively correlated with LVmax (ρ = 0.604, p cats had a greater LVmax (5.44 mm, IQR 4.83-6.28 mm) than the negative cats (4.76 mm, IQR 4.36-5.32 mm, p = 0.001). Also, the ACE polymorphism genotype was associated with LVmax: the homozygous cats (5.37 mm, IQR 5.14-6.4 mm) had greater LVmax than the heterozygous cats (4.73 mm, IQR 4.41-5.55 mm, p = 0.014). Only the MYBPC3 genotype and body weight were independently associated with wall thickness in multivariable analysis. This study provides evidence that the MYBPC3:R820W mutation is independently associated with LV wall thickness in Ragdoll cats. Body weight is also independently associated with maximum LV wall thickness, but is not currently accounted for in HCM screening. In addition, other genetic modifiers may be associated with variation in LV wall thickness in Ragdolls. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Room temperature synthesis of indium tin oxide nanotubes with high precision wall thickness by electroless deposition.

    Science.gov (United States)

    Boehme, Mario; Ionescu, Emanuel; Fu, Ganhua; Ensinger, Wolfgang

    2011-01-01

    Conductive nanotubes consisting of indium tin oxide (ITO) were fabricated by electroless deposition using ion track etched polycarbonate templates. To produce nanotubes (NTs) with thin walls and small surface roughness, the tubes were generated by a multi-step procedure under aqueous conditions. The approach reported below yields open end nanotubes with well defined outer diameter and wall thickness. In the past, zinc oxide films were mostly preferred and were synthesized using electroless deposition based on aqueous solutions. All these methods previously developed, are not adaptable in the case of ITO nanotubes, even with modifications. In the present work, therefore, we investigated the necessary conditions for the growth of ITO-NTs to achieve a wall thickness of around 10 nm. In addition, the effects of pH and reductive concentrations for the formation of ITO-NTs are also discussed.

  1. Room temperature synthesis of indium tin oxide nanotubes with high precision wall thickness by electroless deposition

    Directory of Open Access Journals (Sweden)

    Mario Boehme

    2011-02-01

    Full Text Available Conductive nanotubes consisting of indium tin oxide (ITO were fabricated by electroless deposition using ion track etched polycarbonate templates. To produce nanotubes (NTs with thin walls and small surface roughness, the tubes were generated by a multi-step procedure under aqueous conditions. The approach reported below yields open end nanotubes with well defined outer diameter and wall thickness. In the past, zinc oxide films were mostly preferred and were synthesized using electroless deposition based on aqueous solutions. All these methods previously developed, are not adaptable in the case of ITO nanotubes, even with modifications. In the present work, therefore, we investigated the necessary conditions for the growth of ITO-NTs to achieve a wall thickness of around 10 nm. In addition, the effects of pH and reductive concentrations for the formation of ITO-NTs are also discussed.

  2. Real-time dielectric-film thickness measurement system for plasma processing chamber wall monitoring.

    Science.gov (United States)

    Kim, Jin-Yong; Chung, Chin-Wook

    2015-12-01

    An in-situ real-time processing chamber wall monitoring system was developed. In order to measure the thickness of the dielectric film, two frequencies of small sinusoidal voltage (∼1 V) signals were applied to an electrically floated planar type probe, which is positioned at chamber wall surface, and the amplitudes of the currents and the phase differences between the voltage and current were measured. By using an equivalent sheath circuit model including a sheath capacitance, the dielectric thickness can be obtained. Experiments were performed in various plasma condition, and reliable dielectric film thickness was obtained regardless of the plasma properties. In addition, availability in commercial chamber for plasma enhanced chemical vapor deposition was verified. This study is expected to contribute to the control of etching and deposition processes and optimization of periodic maintenance in semiconductor manufacturing process.

  3. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output

    DEFF Research Database (Denmark)

    Smerup, Morten Holdgaard; Damkjær, Mads; Brøndum, Emil

    2016-01-01

    cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures......Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted...... by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular...

  4. High Power Laser Beam Welding of Thick-walled Ferromagnetic Steels with Electromagnetic Weld Pool Support

    Science.gov (United States)

    Fritzsche, André; Avilov, Vjaceslav; Gumenyuk, Andrey; Hilgenberg, Kai; Rethmeier, Michael

    The development of modern high power laser systems allows single pass welding of thick-walled components with minimal distortion. Besides the high demands on the joint preparation, the hydrostatic pressure in the melt pool increases with higher plate thicknesses. Reaching or exceeding the Laplace pressure, drop-out or melt sagging are caused. A contactless electromagnetic weld support system was used for laser beam welding of thick ferromagnetic steel plates compensating these effects. An oscillating magnetic field induces eddy currents in the weld pool which generate Lorentz forces counteracting the gravity forces. Hysteresis effects of ferromagnetic steels are considered as well as the loss of magnetization in zones exceeding the Curie temperature. These phenomena reduce the effective Lorentz forces within the weld pool. The successful compensation of the hydrostatic pressure was demonstrated on up to 20 mm thick plates of duplex and mild steel by a variation of the electromagnetic power level and the oscillation frequency.

  5. Contributions towards a monograph of Phoma (Coelomycetes) — VII. Section Sclerophomella: Taxa with thick-walled pseudoparenchymatous pycnidia

    NARCIS (Netherlands)

    Boerema, G.H.; Gruyter, de J.

    1998-01-01

    This paper deals with ten species of Phoma, characterized by thick-walled pseudoparenchymatous pycnidia. They superficially resemble the thick-walled pycnidial phenotype in species of Phoma sect. Plenodomus, but scleroplectenchyma is lacking and teleomorphs belong to Didymella, not Leptosphaeria. Ke

  6. Combined aerobic and resistance exercise training decreases peripheral but not central artery wall thickness in subjects with type 2 diabetes.

    NARCIS (Netherlands)

    Schreuder, T.H.A.; Munckhof, I.C.L. van den; Poelkens, F.; Hopman, M.T.; Thijssen, D.H.

    2015-01-01

    OBJECTIVE: Little is known about the impact of exercise training on conduit artery wall thickness in type 2 diabetes. We examined the local and systemic impact of exercise training on superficial femoral (SFA), brachial (BA), and carotid artery (CA) wall thickness in type 2 diabetes patients and con

  7. Ultrasound Estimated Bladder Weight and Measurement of Bladder Wall Thickness-Useful Noninvasive Methods for Assessing the Lower Urinary Tract?

    NARCIS (Netherlands)

    E. Bright; M. Oelke; A. Tubaro; P. Abrams

    2010-01-01

    Purpose: In the last decade interest has arisen in the use of ultrasound derived measurements of bladder wall thickness, detrusor wall thickness and ultrasound estimated bladder weight as potential diagnostic tools for conditions known to induce detrusor hypertrophy. However, to date such measuremen

  8. Combined aerobic and resistance exercise training decreases peripheral but not central artery wall thickness in subjects with type 2 diabetes.

    NARCIS (Netherlands)

    Schreuder, T.H.A.; Munckhof, I.C.L. van den; Poelkens, F.; Hopman, M.T.; Thijssen, D.H.

    2015-01-01

    OBJECTIVE: Little is known about the impact of exercise training on conduit artery wall thickness in type 2 diabetes. We examined the local and systemic impact of exercise training on superficial femoral (SFA), brachial (BA), and carotid artery (CA) wall thickness in type 2 diabetes patients and

  9. Correlation between capillary oxygen saturation and small intestinal wall thickness in the equine colic patient.

    Science.gov (United States)

    Mirle, Elisabeth; Wogatzki, Anna; Kunzmann, Robert; Schoenfelder, Axel M; Litzke, Lutz F

    2017-01-01

    The surgical evaluation of haemorrhagic infarcted intestine and the decision for or against bowel resection require a lot of experience and are subjective. The aim of this prospective, clinical study was to examine the correlation between oxygen saturation and small intestinal wall (IW) thickness, using two objective methods. In 22 colicky horses, the blood flow, oxygen saturation and relative amount of haemoglobin were measured intraoperatively via laser Doppler and white light spectroscopy (O2C, oxygen to see, LEA Medizintechnik) at six measuring points (MPs) in small and large intestines. Furthermore, the IW thickness was measured ultrasonographically. Nine of 22 horses had an increased small IW thickness greater than 4 mm (Freeman 2002, Scharner and others 2002, le Jeune and Whitcomb 2014) at measuring point 1 (MP1) (strangulated segment), four horses had a thickened bowel wall at measuring point 3 (MP3) (poststenotic) and one at measuring point 2 (MP2). The oxygen saturation was 0 at MP1 in six horses, at MP3 in two horses and at MP2 (prestenotic) in one. Oxygen saturation and small IW thickness were independent of each other at MP1 and MP2. At MP3, the two parameters were negatively correlated. In summary, it is not possible to draw conclusions about oxygen saturation based on IW thickness.

  10. Modelling the solidification of ductile cast iron parts with varying wall thicknesses

    DEFF Research Database (Denmark)

    Bjerre, Mathias Karsten; Tiedje, Niels Skat; Thorborg, Jesper

    2015-01-01

    ] with a 2D FE solution of the heat conduction equation is developed in an in-house code and model parameters are calibrated using experimental data from representative castings made of ductile cast iron. The main focus is on the influence of casting thickness and resulting local cooling conditions......In the present paper modelling the solidification of cast iron parts is considered. Common for previous efforts in this field is that they have mainly considered thin walled to medium thickness castings. Hence, a numerical model combining the solidification model presented by Lesoultet al. [1...

  11. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

    Science.gov (United States)

    Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias

    2016-02-01

    Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output.

  12. Standard guide for mutual inductance bridge applications for wall thickness determinations in boiler tubing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide describes a procedure for obtaining relative wall thickness indications in ferromagnetic and non-ferromagnetic steels using the mutual inductance bridge method. The procedure is intended for use with instruments capable of inducing two substantially identical magnetic fields and noting the change in inductance resulting from differing amounts of steel. It is used to distinguish acceptable wall thickness conditions from those which could place tubular vessels or piping at risk of bursting under high temperature and pressure conditions. 1.2 This guide is intended to satisfy two general needs for users of industrial Mutual Inductance Bridge (MIB) equipment: (1) the need for a tutorial guide addressing the general principles of Mutual Inductance Bridges as they apply to industrial piping; and (2) the need for a consistent set of MIB performance parameter definitions, including how these performance parameters relate to MIB system specifications. Potential users and buyers, as well as experienced M...

  13. Effective coarse-grained simulations of super-thick multi-walled carbon nanotubes under torsion

    OpenAIRE

    Jian, Zou; Huang, Xu; Arroyo Balaguer, Marino; Zhang, Sulin

    2009-01-01

    Under torsion and beyond the buckling point, multi-walled carbon nanotubes (MWCNTs) develop a periodic wave-like rippling morphology. Here, we show that torsional rippling deformations can be accurately described by a simple sinusoidal shape function. Combining this observation with the geometry optimization, we develop an effective coarse-grained model that reproduces the complex nonlinear mechanical responses of thick MWCNTs under torsion predicted by large-scale atomistic simulations. Furt...

  14. Influence of surrounding wall thickness on the fatigue resistance of molars restored with ceramic inlay

    Directory of Open Access Journals (Sweden)

    Shizuma Shibata

    2014-06-01

    Full Text Available The purpose of this study was to evaluate the influence of buccal and lingual wall thickness on the fatigue resistance of molars restored with CAD/CAM ceramic inlays. Forty human third molars were selected and divided into 4 groups, according to the remaining surrounding wall thickness chosen for inlay preparation (n = 10: G1, 2.0 mm; G2, 1.5 mm; G3, 1.0 mm; G4, 0.5 mm. All inlays were made from feldspathic ceramic blocks by a CAD/CAM system, and cemented adhesively. After 1 week stored in distilled water at 37 °C, the specimens were subjected to fatigue testing under the following protocol: 5Hz; pre-load of 200 N for 5,000 cycles, followed by increasing loads of 400, 600, 800, 1000, 1200 and 1400 N for 30,000 cycles each. The specimens were cycled until failure or completion of 185,000 cycles. The survival rate of the groups was compared using the Kaplan-Meier survival curves (p > 0.05. All specimens withstood the fatigue protocol (185,000 cycles, representing a 100% survival rate. The Kaplan-Meier survival curves showed no difference between groups. It can be concluded that the remaining tooth wall thickness did not influence the fatigue resistance of molars restored with CAD/CAM ceramic inlays.

  15. Elastic-plastic Transition of Transversely Isotropic Thick-walled Rotating Cylinder under Internal Pressure

    Directory of Open Access Journals (Sweden)

    Sanjeev Sharma

    2009-05-01

    Full Text Available Elastic-plastic stresses for a transversely isotropic thick-walled rotating cylinder under internal pressure have been obtained by using Seth’s transition theory. It has been observed that a thick-walled circular cylinder made of isotropic material yields at the internal surface at a high pressure as compared to cylinder made of transversely isotropic material. With the increase in angular speed, much less pressure is required for initial yielding at the internal surface for transversely isotropic material as compared to isotropic material. For fullyplastic state, circumferential stress is maximum at the external surface. Thick-walled circular cylinder made of transversely isotropic material requires high percentage increase in pressure to become fully plastic as compared to isotropic cylinder. Therefore, circular cylinder made of transversely isotropic material is on the safer side of the design as compared to cylinder made of  isotropic material.Defence Science Journal, 2009, 59(3, pp.260-264, DOI:http://dx.doi.org/10.14429/dsj.59.1519

  16. Increased left ventricular torsion in hypertrophic cardiomyopathy mutation carriers with normal wall thickness

    Directory of Open Access Journals (Sweden)

    Marcus Tim J

    2011-01-01

    Full Text Available Abstract Background Increased left ventricular (LV torsion has been observed in patients with manifest familial hypertrophic cardiomyopathy (HCM, and is thought to be caused by subendocardial dysfunction. We hypothesize that increased LV torsion is already present in healthy mutation carriers with normal wall thickness. Methods Seventeen carriers with an LV wall thickness Results LV volumes, mass and circumferential strain were comparable between groups, whereas LV ejection fraction, torsion and TECS-ratio were increased in carriers compared to controls (63 ± 3% vs. 60 ± 3%, p = 0.04, 10.1 ± 2.5° vs. 7.7 ± 1.2°, p = 0.001, and 0.52 ± 0.14°/% vs. 0.42 ± 0.10°/%, p = 0.02, respectively. Conclusions Carriers with normal wall thickness display increased LV torsion and TECS-ratio with respect to controls, which might be due to subendocardial myocardial dysfunction. As similar abnormalities are observed in patients with manifest HCM, the changes in healthy carriers may be target for clinical intervention to delay or prevent the onset of hypertrophy.

  17. Design and analysis of Stress on Thick Walled Cylinder with and with out Holes

    Directory of Open Access Journals (Sweden)

    G.Raju

    2015-01-01

    Full Text Available The conventional elastic analysis of thick walled cylinders to final radial & hoop stresses is applicable for the internal pressures up to yield strength of material. The stress is directly proportional to strain up to yield point Beyond elastic point, particularly in thick walled cylinders. The operating pressures are reduced or the material properties are strengthened. There is no such existing theory for the stress distributions around radial holes under impact of varying internal pressure. Present work puts thrust on this area and relation between pressure and stress distribution is plotted graphically based on observations. Here focus is on pure mechanical analysis & hence thermal, effects are not considered. The thick walled cylinders with a radial cross-hole ANSYS Macro program employed to evaluate the fatigue life of vessel. Stresses that remain in material even after removing applied loads are known as residual stresses. These stresses occur only when material begins to yield plastically. Residual stresses can be present in any mechanical structure because of many causes. Residual stresses may be due to the technological process used to make the component. Manufacturing processes lead to plastic deformation. Elasto plastic analysis with bilinear kinematic hardening material is performed to know the effect of hole sizes. It is observed that there are several factors which influence stress intensity factors. The Finite element analysis is conducted using commercial solvers ANSYS & CATIA. Theoretical formulae based results are obtained from MATLAB programs. The results are presented in form of graphs and tables.

  18. Influence of surrounding wall thickness on the fatigue resistance of molars restored with ceramic inlay.

    Science.gov (United States)

    Shibata, Shizuma; Gondo, Renata; Araújo, Élito; Mello Roesler, Carlos Rodrigo de; Baratieri, Luiz Narciso

    2014-01-01

    The purpose of this study was to evaluate the influence of buccal and lingual wall thickness on the fatigue resistance of molars restored with CAD/CAM ceramic inlays. Forty human third molars were selected and divided into 4 groups, according to the remaining surrounding wall thickness chosen for inlay preparation (n=10): G1, 2.0 mm; G2, 1.5 mm; G3, 1.0 mm; G4, 0.5 mm. All inlays were made from feldspathic ceramic blocks by a CAD/CAM system, and cemented adhesively. After 1 week stored in distilled water at 37 °C, the specimens were subjected to fatigue testing under the following protocol: 5Hz; pre-load of 200 N for 5,000 cycles, followed by increasing loads of 400, 600, 800, 1000, 1200 and 1400 N for 30,000 cycles each. The specimens were cycled until failure or completion of 185,000 cycles. The survival rate of the groups was compared using the Kaplan-Meier survival curves (p>0.05). All specimens withstood the fatigue protocol (185,000 cycles), representing a 100% survival rate. The Kaplan-Meier survival curves showed no difference between groups. It can be concluded that the remaining tooth wall thickness did not influence the fatigue resistance of molars restored with CAD/CAM ceramic inlays.

  19. Polarizabilities of an annular cut in the wall of an arbitrary thickness

    Science.gov (United States)

    Kurennoy, S. S.

    1996-07-01

    The electric and magnetic polarizabilities of an aperture are its important characteristics in the theory of aperture coupling and diffraction of EM waves. The beam coupling impedances due to a small discontinuity on the chamber wall of an accelerator can also be expressed in terms of the polarizabilities of the discontinuity. The polarizabilities are geometrical factors which can be found by solving a static (electric or magnetic) problem. However, they are known in an explicit analytical form only for a few simple-shaped discontinuities, such as an elliptic hole in a thin wall. In the present paper the polarizabilities of a ring-shaped cut in the wall of an arbitrary thickness are studied using a combination of analytical, variational and numerical methods. The results are applied to estimate the coupling impedances of button-type beam position monitors.

  20. Polarizabilities of an annular cut in the wall of an arbitrary thickness

    CERN Document Server

    Kurennoy, S S

    1995-01-01

    The electric and magnetic polarizabilities of an aperture are its important characteristics in the theory of aperture coupling and diffraction of EM waves. The beam coupling impedances due to a small discontinuity on the chamber wall of an accelerator can also be expressed in terms of the polarizabilities of the discontinuity. The polarizabilities are geometrical factors which can be found by solving a static (electric or magnetic) problem. However, they are known in an explicit analytical form only for a few simple-shaped discontinuities, such as an elliptic hole in a thin wall. In the present paper the polarizabilities of a ring-shaped cut in the wall of an arbitrary thickness are studied using a combination of analytical, variational and numerical methods. The results are applied to estimate the coupling impedances of button-type beam position monitors.

  1. Seasonal distribution of processes responsible for radial diameter and wall thickness of Scots pine tracheids

    Directory of Open Access Journals (Sweden)

    G. F. Antonova

    2015-04-01

    Full Text Available The timeframes of processes responsible for the number of cells, their radial diameters and wall thickness in annual wood increment of Scots pine in the course of season vegetation were studied. The number of cells produced by cambium, cell radial diameters in the cell growth expansion zone and the thickness/wall tracheid cross-sectional area in the secondary wall thickening zone were estimated at the transverse sections of samples taken from the stems in 10 days. The data obtained were used for the calculation of the development durations of tracheids in the zones of differentiation and the dependence of these characteristics of the processes on air temperature. Throughout the season, the processes of the production by cambium of early and late tracheids, their radial growth and secondary wall thickening occurs at different times and may overlap each with another in time. In the conditions of Middle Siberia (Russia, the production of cambium cells was observed in June and July. Radial diameter growth of earlywood tracheids occurred mainly in June, latewood tracheids – in July. The development of secondary wall thickening of earlywood cells occurred in June-July, latewood ones – in August to the first half of September. Hydrothermal conditions of these months affect considerably the morphological parameters of the tracheids. Each of the processes reacted to environmental factors independently and had their own optimum temperatures causing the differences in cell wall biomass deposited in separate periods of the season. The data should be considered in addressing the problem of productivity and quality of wood produced in different climate conditions.

  2. Transabdominal ultrasound for standardized measurement of bowel wall thickness in normal children and those with Crohn's disease.

    Science.gov (United States)

    Chiorean, Liliana; Schreiber-Dietrich, Dagmar; Braden, Barbara; Cui, XinWu; Dietrich, Christoph F

    2014-12-01

    The intestinal wall can be visualized using high resolution transabdominal ultrasound (TUS). TTUS measurement of the bowel wall thickness has been described in adults but data are lacking in children. The purpose of this prospective study was to sonographically investigate bowel wall thickness in healthy children and children with Crohn's disease. TUS (5-15 MHz) of the intestine was performed in 58 healthy children (age range 3 to 16 years) and in 30 children with Crohn's disease (age range 8 to 17 years). The following regions were assessed and bowel wall thickness measured: terminal ileum, cecum, right flexure, and sigmoid colon. In patients with Crohn's disease, the involved region was additionally assessed regarding length of involved segment and sonographic signs of transmural inflammation and fistula. TUS allowed adequate measurement of bowel wall thickness in all 58 healthy children (100%) and in all 30 Crohn's disease patients (100%). The bowel wall thickness significantly differed between groups. Bowel wall thickness (mean +/- SD) in all segments was less then 2 mm in all healthy children (1.0+/-0.1 mm terminal ileum, 1.1+/-0.1 mm cecum, 1.1+/-0.1 mm right flexure, and 1.3+/-0.1 mm sigmoid colon). In Crohn's disease patients, bowel wall thickness was ≥ 3 mm in the ileocecal region and was significantly increased (5.1+/-1.9 mm) compared to the healthy children. The mean length of involved segment was 15+/-6.5 cm [5 - 30 cm]. Additional findings in Crohn's disease patients were: transmural inflamation (3/30), interenteric fistula (3/30), gastrocolic fistula (1/30) and vesicoenteric fistula (1/30). Similar to adults, normal bowel wall thickness in children is always less than 2 mm. In all patients with Crohn's disease, increased bowel wall thickness could be detected. TUS is a helpful tool in the diagnosis and assessment of activity and complications in Crohn's disease.

  3. Accurate measurement of respiratory airway wall thickness in CT images using a signal restoration technique

    Science.gov (United States)

    Park, Sang Joon; Kim, Tae Jung; Kim, Kwang Gi; Lee, Sang Ho; Goo, Jin Mo; Kim, Jong Hyo

    2008-03-01

    Airway wall thickness (AWT) is an important bio-marker for evaluation of pulmonary diseases such as chronic bronchitis, bronchiectasis. While an image-based analysis of the airway tree can provide precise and valuable airway size information, quantitative measurement of AWT in Multidetector-Row Computed Tomography (MDCT) images involves various sources of error and uncertainty. So we have developed an accurate AWT measurement technique for small airways with three-dimensional (3-D) approach. To evaluate performance of these techniques, we used a set of acryl tube phantom was made to mimic small airways to have three different sizes of wall diameter (4.20, 1.79, 1.24 mm) and wall thickness (1.84, 1.22, 0.67 mm). The phantom was imaged with MDCT using standard reconstruction kernel (Sensation 16, Siemens, Erlangen). The pixel size was 0.488 mm × 0.488 mm × 0.75 mm in x, y, and z direction respectively. The images were magnified in 5 times using cubic B-spline interpolation, and line profiles were obtained for each tube. To recover faithful line profile from the blurred images, the line profiles were deconvolved with a point spread kernel of the MDCT which was estimated using the ideal tube profile and image line profile. The inner diameter, outer diameter, and wall thickness of each tube were obtained with full-width-half-maximum (FWHM) method for the line profiles before and after deconvolution processing. Results show that significant improvement was achieved over the conventional FWHM method in the measurement of AWT.

  4. Comparison of Turbulent Heat-Transfer Results for Uniform Wall Heat Flux and Uniform Wall Temperature

    Science.gov (United States)

    Siegel, R.; Sparrow, E. M.

    1960-01-01

    The purpose of this note is to examine in a more precise way how the Nusselt numbers for turbulent heat transfer in both the fully developed and thermal entrance regions of a circular tube are affected by two different wall boundary conditions. The comparisons are made for: (a) Uniform wall temperature (UWT); and (b) uniform wall heat flux (UHF). Several papers which have been concerned with the turbulent thermal entrance region problem are given. 1 Although these analyses have all utilized an eigenvalue formulation for the thermal entrance region there were differences in the choices of eddy diffusivity expressions, velocity distributions, and methods for carrying out the numerical solutions. These differences were also found in the fully developed analyses. Hence when making a comparison of the analytical results for uniform wall temperature and uniform wall heat flux, it was not known if differences in the Nusselt numbers could be wholly attributed to the difference in wall boundary conditions, since all the analytical results were not obtained in a consistent way. To have results which could be directly compared, computations were carried out for the uniform wall temperature case, using the same eddy diffusivity, velocity distribution, and digital computer program employed for uniform wall heat flux. In addition, the previous work was extended to a lower Reynolds number range so that comparisons could be made over a wide range of both Reynolds and Prandtl numbers.

  5. Inverse Transient Analysis for Classification of Wall Thickness Variations in Pipelines

    Directory of Open Access Journals (Sweden)

    Jeffrey Tuck

    2013-12-01

    Full Text Available Analysis of transient fluid pressure signals has been investigated as an alternative method of fault detection in pipeline systems and has shown promise in both laboratory and field trials. The advantage of the method is that it can potentially provide a fast and cost effective means of locating faults such as leaks, blockages and pipeline wall degradation within a pipeline while the system remains fully operational. The only requirement is that high speed pressure sensors are placed in contact with the fluid. Further development of the method requires detailed numerical models and enhanced understanding of transient flow within a pipeline where variations in pipeline condition and geometry occur. One such variation commonly encountered is the degradation or thinning of pipe walls, which can increase the susceptible of a pipeline to leak development. This paper aims to improve transient-based fault detection methods by investigating how changes in pipe wall thickness will affect the transient behaviour of a system; this is done through the analysis of laboratory experiments. The laboratory experiments are carried out on a stainless steel pipeline of constant outside diameter, into which a pipe section of variable wall thickness is inserted. In order to detect the location and severity of these changes in wall conditions within the laboratory system an inverse transient analysis procedure is employed which considers independent variations in wavespeed and diameter. Inverse transient analyses are carried out using a genetic algorithm optimisation routine to match the response from a one-dimensional method of characteristics transient model to the experimental time domain pressure responses. The accuracy of the detection technique is evaluated and benefits associated with various simplifying assumptions and simulation run times are investigated. It is found that for the case investigated, changes in the wavespeed and nominal diameter of the

  6. Inverse Transient Analysis for Classification of Wall Thickness Variations in Pipelines

    Science.gov (United States)

    Tuck, Jeffrey; Lee, Pedro

    2013-01-01

    Analysis of transient fluid pressure signals has been investigated as an alternative method of fault detection in pipeline systems and has shown promise in both laboratory and field trials. The advantage of the method is that it can potentially provide a fast and cost effective means of locating faults such as leaks, blockages and pipeline wall degradation within a pipeline while the system remains fully operational. The only requirement is that high speed pressure sensors are placed in contact with the fluid. Further development of the method requires detailed numerical models and enhanced understanding of transient flow within a pipeline where variations in pipeline condition and geometry occur. One such variation commonly encountered is the degradation or thinning of pipe walls, which can increase the susceptible of a pipeline to leak development. This paper aims to improve transient-based fault detection methods by investigating how changes in pipe wall thickness will affect the transient behaviour of a system; this is done through the analysis of laboratory experiments. The laboratory experiments are carried out on a stainless steel pipeline of constant outside diameter, into which a pipe section of variable wall thickness is inserted. In order to detect the location and severity of these changes in wall conditions within the laboratory system an inverse transient analysis procedure is employed which considers independent variations in wavespeed and diameter. Inverse transient analyses are carried out using a genetic algorithm optimisation routine to match the response from a one-dimensional method of characteristics transient model to the experimental time domain pressure responses. The accuracy of the detection technique is evaluated and benefits associated with various simplifying assumptions and simulation run times are investigated. It is found that for the case investigated, changes in the wavespeed and nominal diameter of the pipeline are both important

  7. The Boiler Tube Wall Thickness Quantitative Evaluation Fusing the Magnetic and Ultrasonic Technique

    Institute of Scientific and Technical Information of China (English)

    SONG Xiaochun; HUANG Songling; ZHAO Daxing

    2006-01-01

    Wall thickness is always a key index for boiler tube inspection in power plant, in order to improve the inspection efficiency and accuracy, a new method fusing the magnetic and ultrasonic technique was proposed. The magnetic technique was used to do full inspection and locate the flaws, and the ultrasonic was employed to implement further quantitative inspection accurately. After comparing the precision of the polynomial, exponential and logarithmic function, the polynomial model was selected to fit the relations between the wall thickness and the peak value of magnetic signals, and the data measured by ultrasonic thickness meter was used to calibrate the model parameters online, the defect depth can be sized quickly. The experimental results demonstrate that the model used in this system has better accuracy than the statistics relation model clearly, and it is also suitable for defect evaluation real-time. Moreover, it is unnecessary to have much more experimental data for the curve fitting technology, so it has better practicability than the other methods.

  8. Injection-moulded models of major and minor arteries: the variability of model wall thickness owing to casting technique.

    Science.gov (United States)

    O'Brien, T; Morris, L; O'Donnell, M; Walsh, M; McGloughlin, T

    2005-09-01

    Cardiovascular disease of major and minor arteries is a common cause of death in Western society. The wall mechanics and haemodynamics within the arteries are considered to be important factors in the disease formation process. This paper is concerned with the development of an efficient computer-integrated technique to manufacture idealized and realistic models of diseased major and minor arteries from radiological images and to address the issue of model wall thickness variability. Variations in wall thickness from the original computer models to the final castings are quantified using a CCD camera. The results found that wall thickness variation from the major and minor idealized artery models to design specification were insignificant, up to a maximum of 16 per cent. In realistic models, however, differences were up to 23 per cent in the major arterial models and 58 per cent in the minor arterial models, but the wall thickness variability remained within the limits of previously reported wall thickness results. It is concluded that the described injection moulding procedure yields idealized and realistic castings suitable for use in experimental investigations, with idealized models giving better agreement with design. Wall thickness is variable and should be assessed after the models are manufactured.

  9. Ultraviolet and infrared studies of the single-walled and multi-walled carbon nanotube films with different thickness

    Energy Technology Data Exchange (ETDEWEB)

    Abouelsayed, A., E-mail: a_sobhi77@yahoo.com [Spectroscopy Department, Physics Division, National Research Centre, 33 El Bohouth st. (Former El Tahrir st.), Dokki, Giza P.O. 12622 (Egypt); Eisa, Wael H. [Spectroscopy Department, Physics Division, National Research Centre, 33 El Bohouth st. (Former El Tahrir st.), Dokki, Giza P.O. 12622 (Egypt); Dawy, M. [Physical Chemistry Department, Inorganic Chemical Industries and Mineral Resources Division National Research Centre, 33 El Bohouth st. (former El Tahrir st.), Dokki, Giza P.O. 12622 (Egypt); Shabaka, A. [Spectroscopy Department, Physics Division, National Research Centre, 33 El Bohouth st. (Former El Tahrir st.), Dokki, Giza P.O. 12622 (Egypt)

    2016-02-15

    Ultraviolet and infrared transmission measurements on an unoriented single-wall (SWCNTs) and multi-wall (MWCNTs) carbon nanotubes films were performed over a frequency range 190–2500 nm for the four different films. A clear change in the fine structure of the infrared spectrum for different films. The higher-energy optical absorption bands, which correspond to transitions across the Van Hove singularities, are not observed in the measured frequency range in the case of MWCNTs films. The broad excitation in the low-energy range below 0.025 eV (Drude peak (E{sub M0})) are attributed to the contributions from metallic carriers localized in a finite length. This Drude peak (E{sub M0}) at low-energies is decreased in in case of MWCNTs, which suggests a progressive transition of metallic tubes to insulating state. The unoriented MWCNTs films have an average thickness of about 200–400 nm. The scanning electron microscope pictures of the SWCNTs and the MWCNTs films illustrate the morphological differences between the four studied samples. The volume fraction of the carbon nanotubes in all films appears to be the same, although there is a difference for particles other than nanotubes in the films.

  10. Numerical Simulation of Transient 3-D Turbulent Heated Jet into Crossflow in a Thick-Wall T-Junction Pipe

    Institute of Scientific and Technical Information of China (English)

    Wu Hailing; Chen Tingkuan; Luo Yushan; Wang Haijun

    2001-01-01

    The present work is to investigate the transient three-dimensional heated turbulent jet into crossflow in a thick wall T-junction pipe using CFD package. Two cases with the jet-to-crossflow velocity ratio of 0.05 and 0.5 are computed, with a finite-volume method utilizing k-ε turbulent model. Comparison of the steady-state computations with measured data shows good qualitative agreement. Transient process of injection is simulated to examine the thermal shock on the T-junction component. Temporal temperature of the component is acquired by thermal coupling with the fluid. Via analysis of the flow and thermal characteristics, factors causing the thermal shock are studied. Optimal flow rates are discussed to reduce the thermal shock.

  11. Structure and Properties of Thick-Walled Joints of Alloy 1570s Prepared by Friction Stir Welding

    Science.gov (United States)

    Velichko, O. V.; Ivanov, S. Yu.; Karkhin, V. A.; Lopota, V. A.; Makhin, I. D.

    2016-09-01

    The microstructure and mechanical properties of thick-walled joints of Al - Mg - Sc alloy 1570S, prepared by friction stir welding are studied. Joint microstructural and mechanical inhomogeneity are revealed.

  12. Investigation of torsional vibrations in thick walled hollow poroelastic cylinder using Biot's extension theory

    Indian Academy of Sciences (India)

    Malla Reddy Perati; Rajitha Gurijala

    2015-09-01

    This paper deals with the study of torsional vibrations of thick walled hollow poroelastic cylinder using Biot's extension theory. Considering the boundaries to be stress free, the frequency equation is obtained in the presence of dissipation which is transcendental and complex valued in nature. In the special case of poroelastic thin shell, frequency equation is separated into two real valued equations giving propagation velocity and attenuation coefficient. From the numerical results in the case of sandy sediment, it is clear that the values of propagation velocity are, in general, less than that of attenuation coefficient.

  13. Increased wall thickness using ultrasonography is associated with inflammation in an animal model of experimental colitis

    Directory of Open Access Journals (Sweden)

    Lied GA

    2012-10-01

    Full Text Available Gülen Arslan Lied,1 Anne Marita Milde,2 Kim Nylund,1,3 Maja Mujic,1 Tore Grimstad,1,4 Trygve Hausken,1,3 Odd Helge Gilja1,31Institute of Medicine, University of Bergen, Norway; 2Department of Biological and Medical Psychology, University of Bergen, Norway; 3National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway; 4Division of Gastroenterology, Stavanger University Hospital, Stavanger, NorwayAbstract: Experimentally induced colitis is used in animals to investigate pathophysiological mechanisms in inflammatory bowel disease. When following disease course and treatment effects, it should be possible to perform repeated measurements without harming the animals. This pilot study was performed to investigate whether transabdominal ultrasound using a clinical scanner could be used on rats to demonstrate bowel inflammation in an experimental colitis model. Colitis was induced by either 5% dextran sodium sulfate (DSS in drinking water for 7 days or a single dose of intracolonic trinitrobenzene sulfonic acid (TNBS. Using ultrasonography, wall thickness of distal colon, cecum, and small bowel was recorded prior to and after DSS, and prior to, 2, and 7 days after TNBS. Blood (tumor necrosis factor [TNF]-alpha and fecal samples (HemoFEC occult blood were taken from each group on the same days as sonography. Thereafter, rats were killed and specimens for histology were taken. Wall thickness of distal colon, not of cecum or small bowel, increased significantly after 7 days of DSS, and wall thickness of both distal colon and small bowel increased on day 2 and 7 after TNBS. TNF-alpha increased after 7 days in the latter group only. There was a significant correlation between ultrasonographic measurements and combined histology score of distal colon in the DSS group. HemoFEC was also positive in accordance with sonographic and histological features. Increased intestinal wall thickness in response to both DSS- and TNBS

  14. IFE thick liquid wall chamber dynamics: Governing mechanisms andmodeling and experimental capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Raffray, A.R.; Meier, W.; Abdel-Khalik, S.; Bonazza, R.; Calderoni, P.; Debonnel, C.S.; Dragojlovic, Z.; El-Guebaly, L.; Haynes,D.; Latkowski, J.; Olson, C.; Peterson, P.F.; Reyes, S.; Sharpe, P.; Tillack, M.S.; Zaghloul, M.

    2005-01-24

    For thick liquid wall concepts, it is important to understand the different mechanisms affecting the chamber dynamics and the state of the chamber prior to each shot a compared with requirements from the driver and target. These include ablation mechanisms, vapor transport and control, possible aerosol formation, as well as protective jet behavior. This paper was motivated by a town meeting on this subject which helped identify the major issues, assess the latest results, review the capabilities of existing modeling and experimental facilities with respect to addressing remaining issues, and helping guide future analysis and R&D efforts; the paper covers these exact points.

  15. Exact and numerical elastodynamic solutions for thick-walled functionally graded cylinders subjected to pressure shocks

    Energy Technology Data Exchange (ETDEWEB)

    Shariyat, M., E-mail: m_shariyat@yahoo.co [Faculty of Mechanical Engineering, K.N. Toosi University of Technology, Pardis Street, Molla-Sadra Avenue, Vanak Square, P.O. Box: 19395-1999, Tehran 19991 43344 (Iran, Islamic Republic of); Nikkhah, M.; Kazemi, R. [Faculty of Mechanical Engineering, K.N. Toosi University of Technology, Pardis Street, Molla-Sadra Avenue, Vanak Square, P.O. Box: 19395-1999, Tehran 19991 43344 (Iran, Islamic Republic of)

    2011-02-15

    In the present paper, analytical and numerical elastodynamic solutions are developed for long thick-walled functionally graded cylinders subjected to arbitrary dynamic and shock pressures. Both transient dynamic response and elastic wave propagation characteristics are studied in these non-homogeneous structures. Variations of the material properties across the thickness are described according to both polynomial and power law functions. A numerically consistent transfinite element formulation is presented for both functions whereas the exact solution is presented for the power law function. The FGM cylinder is not divided into isotropic sub-cylinders. An approach associated with dividing the dynamic radial displacement expression into quasi-static and dynamic parts and expansion of the transient wave functions in terms of a series of the eigenfunctions is employed to propose the exact solution. Results are obtained for various exponents of the functions of the material properties distributions, various radius ratios, and various dynamic and shock loads.

  16. Determination of optimum insulation thicknesses using economical analyse for exterior walls of buildings with different masses

    Directory of Open Access Journals (Sweden)

    Okan Kon

    2017-07-01

    Full Text Available In this study, five different cities were selected from the five climatic zones according to Turkish standard TS 825, and insulation thicknesses of exterior walls of sample buildings were calculated by using optimization. Vertical perforated bricks with density of 550 kg/m3 and 1000 kg/m3 were chosen within the study content. Glass wool, expanded polystyrene (XPS, extruded polystyrene (EPS were considered as insulation materials. Additionally, natural gas, coal, fuel oil and LPG were utilized as fuel for heating process while electricity was used for cooling.  Life cycle cost (LCC analysis and degree-day method were the approaches for optimum insulation thickness calculations. As a result, in case of usage vertical perforated bricks with density of 550 kg/m3 and 1000 kg/m3 resulted different values in between 0.005-0.007 m (5-7 mm in the optimum insulation thickness calculations under different insulation materials.  Minimum optimum insulation thickness was calculated in case XPS was preferred as insulation material, and the maximum one was calculated in case of using glass wool.

  17. Positive association between increased popliteal artery vessel wall thickness and generalized osteoarthritis: is OA also part of the metabolic syndrome?

    Energy Technology Data Exchange (ETDEWEB)

    Kornaat, Peter R.; Sharma, Ruby; Geest, Rob J. van der; Lamb, Hildo J.; Bloem, Johan L.; Watt, Iain [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Kloppenburg, Margreet [Leiden University Medical Center, Department of Rheumatology, Leiden (Netherlands); Hellio le Graverand, Marie-Pierre [Pfizer Global Research and Development, New London, CT (United States)

    2009-12-15

    The purpose of the study was to determine if a positive association exists between arterial vessel wall thickness and generalized osteoarthritis (OA). Our hypothesis is that generalized OA is another facet of the metabolic syndrome. The medical ethical review board of our institution approved the study. Written informed consent was obtained from each patient prior to the study. Magnetic resonance (MR) images of the knee were obtained in 42 patients who had been diagnosed with generalized OA at multiple joint sites. Another 27 MR images of the knee were obtained from a matched normal (non-OA) reference population. Vessel wall thickness of the popliteal artery was quantitatively measured by dedicated software. Linear regression models were used to investigate the association between vessel wall thickness and generalized OA. Adjustments were made for age, sex, and body mass index (BMI). Confidence intervals (CI) were computed at the 95% level and a significance level of {alpha} = 0.05 was used. Patients in the generalized OA population had a significant higher average vessel wall thickness than persons from the normal reference population (p {<=} {alpha}), even when correction was made for sex, age, and BMI. The average vessel wall thickness of the popliteal artery was 1.09 mm in patients with generalized OA, and 0.96 mm in the matched normal reference population. The association found between increased popliteal artery vessel wall thickness and generalized osteoarthritis suggests that generalized OA might be another facet of the metabolic syndrome. (orig.)

  18. Quantification of progression and regression of descending thoracic aortic wall thickness by enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Kenichi; Takasu, Junichiro; Yamamoto, Rie; Taguchi, Rie; Itani, Yasutaka; Ito, Yuichi; Watanabe, Shigeru; Masuda, Yoshiaki [Chiba Univ. (Japan). School of Medicine

    2001-04-01

    The purpose of this study is to verify the usefulness of the quantification of aortic wall involvement by enhanced computed tomography (CT). One-hundred thirteen Japanese patients underwent two enhanced CT of the descending thoracic aorta at intervals. We sliced the descending thoracic aorta continuously from the level of the tracheal bifurcation with 1 cm intervals, and we defined aortic wall volume (AWV) (cm{sup 3}) as the sum of a 7-slice area of aortic wall involving calcification. The average of AWV increased from 7.95{+-}2.92 cm{sup 3} to 8.70{+-}2.98 cm{sup 3}. The developmental rate of AWV ({delta}AWV) was 0.270{+-}0.281 cm{sup 3}/year. {delta}AWV did not have a significant correlation with any risk factor at the baseline. {delta}AWV had significant correlation with total cholesterol, (LDL-C) low-density lipoprotein cholesterol and LDL-C/(HDL-C) high-density lipoprotein cholesterol ratio at the follow-up, and by multivariate analysis with only the LDL-C/HDL-C ratio. {delta}AWV was not correlated with the intake status of hypoglycemic, antihypertensive or lipid-lowering drugs. The cut-off level of total cholesterol with the most significant odds ratio for progression of aortic wall was 190 mg/dl, and that of LDL-C was 130 mg/dl. This method proved to be useful for the non-invasive assessment of aortic wall thickness. (author)

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    Lovinger Zev

    2015-01-01

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

  1. Maxillary sinus lateral wall thickness and morphologic patterns in the atrophic posterior maxilla.

    Science.gov (United States)

    Monje, Alberto; Catena, Andrés; Monje, Florencio; Gonzalez-García, Raúl; Galindo-Moreno, Pablo; Suarez, Fernando; Wang, Hom-Lay

    2014-05-01

    The aim of the present study is to examine the sinus lateral wall thickness (LWT) of atrophic posterior maxilla (maxillary LWT. Four hundred fourteen measures were taken from 140 consecutive patients that met the inclusion criteria. On the selected sagittal section, a built-in digital caliper recorded in millimeters the RH and LWT (a perpendicular line at 3, 5, 7, 10, 13, and 15 mm from the lowest point of the sinus floor). Edentulous spans were further classified as complete edentulous atrophic maxilla (CEM) and partial edentulous atrophic maxilla (PEM). The mixed linear model was used to test the effects of sex, type of edentulism, edentulous span, and RH on the measurement of the LWT of the sinus. Mean LWT for PEM was 1.71 ± 0.12 mm, and for CEM, 1.57 ± 0.07 mm (P = 0.01). The mixed model yielded significant effect of edentulous span (P = 0.048) and interactions among type of edentulism and edentulous span (P maxillary sinus lateral wall tends to increase in thickness from the second premolar to the second molar and from 5 mm up to 15 mm. In addition, RH, presence of teeth adjacent to the edentulous atrophic ridge, and age were shown to influence maxillary sinus LWT.

  2. Dissipative particle dynamics study of relationship between wall thickness and size in polymer vesicles

    Science.gov (United States)

    Xiao, Mengying; Wang, Rong; Xie, Daiqian

    2012-02-01

    Vesicles and membrane properties have long been thought to be essential for reproducing the natural environment of living cells. By using dissipative particle dynamics method, we have studied the relationship between wall thickness and size of vesicles obtained from A1BnA1 block copolymers, where block A is hydrophilic and block B is hydrophobic. Our findings suggest that, the wall thickness is sensitive to the size of vesicles at a low block length ratio of B/A, but insensitive to the size at a large ratio. It shows both weak and strong effects with a crossover point in between. These behaviors are consistent with the experimental results of Eisenberg and co-workers. Besides, an additional crossover point also has been observed. With the B/A ratio increases, the relationship goes from strong to weak behavior, and this transformation first appears to affect the outer area for large sized vesicles, and then to the inner area for small sized vesicles. These results may also be useful in delivery applications through controlling the hydrophobic membrane and the hydrophilic coronas.

  3. Optimum Insulation Thickness for Walls and Roofs for Reducing Peak Cooling Loads in Residential Buildings in Lahore

    Directory of Open Access Journals (Sweden)

    SIBGHA SIDDIQUE SIDDIQUE

    2016-10-01

    Full Text Available Thermal insulation is the most effective energy saving measure for cooling in buildings. Therefore, the main subject of many engineering investigations is the selection and determination of the optimum insulation thickness. In the present study, the optimum insulation thickness on external walls and roofs is determined based on the peak cooling loads for an existing residential building in Lahore, Pakistan. Autodesk® Revit 2013 is used for the analysis of the building and determination of the peak cooling loads. The analysis shows that the optimum insulation thickness to reduce peak cooling loads up to 40.1% is 1 inch for external walls and roof respectively.

  4. Crack growth in the through-thickness direction of hydrided thin-wall Zircaloy sheet

    Science.gov (United States)

    Raynaud, Patrick A.; Koss, Donald A.; Motta, Arthur T.

    2012-01-01

    In a reactivity-initiated accident, cladding failure may occur by crack initiation within a defect such as a hydride rim or blister and subsequent crack propagation through the thickness of the thin-wall cladding. In such a circumstance, determining the cladding resistance to crack propagation in the through-thickness direction is crucial to predicting cladding failure. To address this issue, through-thickness crack propagation in hydrided Zircaloy-4 sheet was analyzed at 25 °C, 300 °C, and 375 °C. At 25 °C, the fracture toughness decreased with increasing hydrogen content and with an increasing fraction of radial hydrides. Hydride particles fractured ahead of the crack tip, creating a path for crack growth. At both 300 °C and 375 °C, the resistance to crack-growth initiation was sufficiently high that crack extension was often caused by crack-tip blunting. There was no evidence of hydride particles fracturing near the crack tip, and no significant effect of hydrogen content on fracture toughness was observed at these elevated temperatures.

  5. Analytical and experimental investigations into the controlled energy absorption characteristics of thick-walled tubes with circumferential grooves

    Energy Technology Data Exchange (ETDEWEB)

    Darvizeh, Abolfazl [Islamic Azad University, Bandar-e Anzali (Iran, Islamic Republic of); Darvizeh, Mansour; Ansari, Reza; Meshkinzar, Ata [University of Guilan, Rasht (Iran, Islamic Republic of)

    2014-10-15

    In this paper, the energy absorption characteristics of grooved circular tubes are investigated under quasi-static loading condition. For experiments, thick-walled tubes with circumferential grooves are prepared. The grooves divide the thick-walled tube into several shorter thin-walled portions. Specimens are subjected to axial crushing load to observe the effect of distribution of circular grooves on the deformation mechanism and energy absorption capacity. Geometrical parameters of the specimens are designed utilizing the Taguchi method to cover a reasonably wide range of groove length-to-wall thickness ratios. An analytical approach based on the concept of energy dissipation through the plastic hinges is applied. Taking the effect of strain hardening into account, the obtained analytical results are in good agreement with the experimental ones. The agreement between analytical and experimental results may indicate the validity of the proposed analytical approach. Desirable mechanism of deformation observed justifies the pre-forming method for obtaining favorable energy absorption characteristics.

  6. A method of computing the transient temperature of thick walls from arbitrary variation of adiabatic-wall temperature and heat-transfer coefficient

    Science.gov (United States)

    Hill, P R

    1958-01-01

    A method of calculating the temperature of thick walls has been developed in which the time series and the response to a unit triangle variation of surface temperature concepts are used, together with essentially standard formulas for transient temperature and heat flow into thick walls. The method can be used without knowledge of the mathematical tools of its development. The method is particularly suitable for determining the wall temperature in one-dimensional thermal problems in aeronautics where there is a continuous variation of the heat-transfer coefficient and adiabatic-wall temperature. The method also offers a convenient means for solving the inverse problem of determining the heat-flow history when temperature history is known.

  7. Development of eddy current testing probe for thick-walled metal plate and quantitative evaluation of cracks

    CERN Document Server

    Sato, K; Uchimoto, T; Takagi, T

    2003-01-01

    This paper demonstrates the crack detection of thick-walled non-magnetic metal plates by eddy current testing, which is difficult because of Kelvin skin effect generally. The purpose of this research is the development of an new eddy current testing probe for cracks in thick-walled plates and crack shapes quantitative evaluation. The probe was designed, based on the numerical computation using 3D fast eddy current code. The advantages of this new probe are strong eddy current on the back of specimens and gentle decrement of eddy current in the thickness direction. Through experiments, we confirmed that this probe can detect the back artificial defect with 0.5 mm thickness on IN-CONEL 718 specimen with 7.0 mm thickness. Reconstruction of crack shapes was performed based on the experimental results with the inverse problem code developed by authors. The length and depth of reconstructed defects approximately agree with those of real crack. (author)

  8. Facilitating protein crystal cryoprotection in thick-walled plastic capillaries by high-pressure cryocooling.

    Science.gov (United States)

    Chen, Yi-Fan; Tate, Mark W; Gruner, Sol M

    2009-06-01

    Many steps in the X-ray crystallographic solution of protein structures have been automated. However, the harvesting and cryocooling of crystals still rely primarily on manual handling, frequently with consequent mechanical damage. An attractive alternative is to grow crystals directly inside robust plastic capillaries that may be cryocooled and mounted on the beamline goniometer. In this case, it is still desirable to devise a way to cryoprotect the crystals, which is difficult owing to the poor thermal conductivity of thick plastic capillary walls and the large thermal mass of the capillary and internal mother liquor. A method is described to circumvent these difficulties. It is shown that high-pressure cryocooling substantially reduced the minimal concentrations of cryoprotectants required to cryocool water inside capillaries without formation of ice crystals. The minimal concentrations of PEG 200, PEG 400 and glycerol necessary for complete vitrification under pressure cryocooling were determined.

  9. Unified solution of limit loads of thick wall cylinder subject to external pressure considering strain softening

    Institute of Scientific and Technical Information of China (English)

    CHEN Changfu; XIAO Shujun; YANG Yu

    2007-01-01

    Based on the unified strength theory [1],a unified strength criterion for strain softening materials,such as concrete or rock,was derived,and the elastic and plastic limit loads of a thick-walled cylinder made of these materials subject to external pressure were also given.In addition,the influence of some factors on the limit loads of such cylinders as the ratio of the external radius to intemal radius,rb/ra,the coefficient b,which reflects the effect of medium principal stress and the normal stress of the relevant surface on the material destroy degree,the ratio of tensile strength to compressed strength of the material,α,and the damage variable β were discussed in detail.Some examples were given and some meaningful results were obtained.

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

    Directory of Open Access Journals (Sweden)

    Mareš T.

    2007-10-01

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

  11. Effect of wall thickness of left ventricle on {sup 201}Tl myocardial SPECT images. Myocardial phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Koto, Masanobu; Kawase, Osami [Kobe Univ. (Japan). Hospital; Namura, Hiroyuki; Yamasaki, Katsuhito; Kono, Michio

    1996-07-01

    {sup 201}Tl myocardial SPECT is known for better sensitivity, specificity, and accuracy than planar images in detecting coronary artery disease and diagnosing myocardial viability. SPECT images arc also superior to planar images in diagnostic sensitivity and anatomical orientation. However, as limitation of the spatial resolution of the machine, we often encounter poor SPECT plower image quality in patients with decreased wall thickness. To test the accuracy of SPECT images in patients with marked thinning of the left ventricular wall, as occurs in dilated cardiomyopathy, we performed a experimental study using myocardial phantom with 7 mm wall thickness. Tomographic image of the phantom images were rather heterogeneous, though no artificial defect was located Dilated cardiomyopathy is thought to be characterized by patchy defects in the left ventricle. Careful attention should be given to elucidating myocardial perfusion in patients with a thin left ventricle wall, as there are technical limitations in addition to clinical features. (author)

  12. Simulation of the development and interaction of instabilities in a relativistic electron beam under variation of the beam wall thickness

    Energy Technology Data Exchange (ETDEWEB)

    Badarin, A. A.; Kurkin, S. A. [Saratov State University (Russian Federation); Koronovskii, A. A. [Yuri Gagarin State Technical University (Russian Federation); Rak, A. O. [Belorussian State University of Informatics and Radioelectronics (Belarus); Hramov, A. E., E-mail: hramovae@gmail.com [Saratov State University (Russian Federation)

    2017-03-15

    The development and interaction of Bursian and diocotron instabilities in an annular relativistic electron beam propagating in a cylindrical drift chamber are investigated analytically and numerically as functions of the beam wall thickness and the magnitude of the external uniform magnetic field. It is found that the interaction of instabilities results in the formation of a virtual cathode with a complicated rotating helical structure and several reflection regions (electron bunches) in the azimuthal direction. It is shown that the number of electron bunches in the azimuthal direction increases with decreasing beam wall thickness and depends in a complicated manner on the magnitude of the external magnetic field.

  13. Development of Wall-Thinning Evaluation Procedure for Nuclear Power Plant Piping—Part 1: Quantification of Thickness Measurement Deviation

    Directory of Open Access Journals (Sweden)

    Hun Yun

    2016-06-01

    Full Text Available Pipe wall thinning by flow-accelerated corrosion and various types of erosion is a significant and costly damage phenomenon in secondary piping systems of nuclear power plants (NPPs. Most NPPs have management programs to ensure pipe integrity due to wall thinning that includes periodic measurements for pipe wall thicknesses using nondestructive evaluation techniques. Numerous measurements using ultrasonic tests (UTs; one of the nondestructive evaluation technologies have been performed during scheduled outages in NPPs. Using the thickness measurement data, wall thinning rates of each component are determined conservatively according to several evaluation methods developed by the United States Electric Power Research Institute. However, little is known about the conservativeness or reliability of the evaluation methods because of a lack of understanding of the measurement error. In this study, quantitative models for UT thickness measurement deviations of nuclear pipes and fittings were developed as the first step for establishing an optimized thinning evaluation procedure considering measurement error. In order to understand the characteristics of UT thickness measurement errors of nuclear pipes and fittings, round robin test results, which were obtained by previous researchers under laboratory conditions, were analyzed. Then, based on a large dataset of actual plant data from four NPPs, a quantitative model for UT thickness measurement deviation is proposed for plant conditions.

  14. Development of wall-thinning evaluation procedure for nuclear power plant piping-part 1: Quantification of thickness measurement deviation

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Hun; Moon, Seung Jae [Dept. of Material Engineering, KEPCO Engineering and Construction, Sungnam (Korea, Republic of); Oh, Young Jin [Dept. of Mechanical Engineering, Hanyang University, Seoul (Korea, Republic of)

    2016-06-15

    Pipe wall thinning by flow-accelerated corrosion and various types of erosion is a significant and costly damage phenomenon in secondary piping systems of nuclear power plants (NPPs). Most NPPs have management programs to ensure pipe integrity due to wall thinning that includes periodic measurements for pipe wall thicknesses using nondestructive evaluation techniques. Numerous measurements using ultrasonic tests (UTs; one of the nondestructive evaluation technologies) have been performed during scheduled outages in NPPs. Using the thickness measurement data, wall thinning rates of each component are determined conservatively according to several evaluation methods developed by the United States Electric Power Research Institute. However, little is known about the conservativeness or reliability of the evaluation methods because of a lack of understanding of the measurement error. In this study, quantitative models for UT thickness measurement deviations of nuclear pipes and fittings were developed as the first step for establishing an optimized thinning evaluation procedure considering measurement error. In order to understand the characteristics of UT thickness measurement errors of nuclear pipes and fittings, round robin test results, which were obtained by previous researchers under laboratory conditions, were analyzed. Then, based on a large dataset of actual plant data from four NPPs, a quantitative model for UT thickness measurement deviation is proposed for plant conditions.

  15. A comparative study on optimum insulation thickness of walls and energy savings in equatorial and tropical climate

    Directory of Open Access Journals (Sweden)

    Modeste Kameni Nematchoua

    2017-06-01

    Full Text Available The increase outdoor temperature acts directly on the indoor climate of buildings. In Cameroon, the energy consumption demand in the buildings sector has been rapidly increasing in recent years; so well that energy supply does not always satisfy demand. Thermal insulation technology can be one of the leading methods for reducing energy consumption in these new buildings. However, choosing the thickness of the insulation material often causes high insulation costs. In the present study, the optimum insulation thickness, energy saving and payback period were calculated for buildings in Yaoundé and Garoua cities, located in two climatic regions in Cameroon. The economic model including the cost of insulation material and the present value of energy consumption and the cost over a life time of 22 years of the building, were used to find the optimum insulation thickness, energy saving, and payback period. Materials that extruded polystyrene were chosen and used for two typical wall structures (concrete block (HCB and compressed stabilized earth block wall (CSEB. The early cooling transmission loads, according to wall orientations and percentage of radiation blocked were calculated using the explicit finite-difference method under steady periodic conditions. As a result, it was found that the west- and east-facing walls are the least favourite in the cooling season, whereas the south and north orientations are the most economical. Although wall orientation had a significant effect on the optimum insulation thickness, it had a more significant effect on energy savings. In equatorial region (Yaoundé, for south orientation, the optimum insulation thickness was 0.08 m for an energy savings of 51.69 $/m2. Meanwhile, in tropical region (Garoua, for north orientation, the optimum insulation thickness was 0.11 m for an energy savings of 97.82 $/m2.

  16. Novel MRI Technique Enables Non-Invasive Measurement of Atrial Wall Thickness.

    Science.gov (United States)

    Varela, Marta; Morgan, Ross; Theron, Adeline; Dillon-Murphy, Desmond; Chubb, Henry; Whitaker, John; Henningsson, Markus; Aljabar, Paul; Schaeffter, Tobias; Kolbitsch, Christoph; Aslanidi, Oleg V

    2017-08-01

    Knowledge of atrial wall thickness (AWT) has the potential to provide important information for patient stratification and the planning of interventions in atrial arrhythmias. To date, information about AWT has only been acquired in post-mortem or poor-contrast computed tomography (CT) studies, providing limited coverage and highly variable estimates of AWT. We present a novel contrast agent-free MRI sequence for imaging AWT and use it to create personalized AWT maps and a biatrial atlas. A novel black-blood phase-sensitive inversion recovery protocol was used to image ten volunteers and, as proof of concept, two atrial fibrillation patients. Both atria were manually segmented to create subject-specific AWT maps using an average of nearest neighbors approach. These were then registered non-linearly to generate an AWT atlas. AWT was 2.4 ± 0.7 and 2.7 ± 0.7 mm in the left and right atria, respectively, in good agreement with post-mortem and CT data, where available. AWT was 2.6 ± 0.7 mm in the left atrium of a patient without structural heart disease, similar to that of volunteers. In a patient with structural heart disease, the AWT was increased to 3.1 ± 1.3 mm. We successfully designed an MRI protocol to non-invasively measure AWT and create the first whole-atria AWT atlas. The atlas can be used as a reference to study alterations in thickness caused by atrial pathology. The protocol can be used to acquire personalized AWT maps in a clinical setting and assist in the treatment of atrial arrhythmias.

  17. Utilization of a global data grid repository in CAD assessment of carotid wall thickness

    Science.gov (United States)

    Gutierrez, Marco A.; Lee, Jasper; Zhou, Zheng; Pilon, Paulo E.; Lage, Silvia G.

    2007-03-01

    A CAD method of calculating wall thickness of carotid vessels addresses the time-consuming issue of using B-mode ultrasound as well as inter- and intra-observer variability in results. Upon selection of a region-of-interest and filtering of a series of ultrasound carotid images, the CAD is able to measure the geometry of the lumen and plaque surfaces using a least-square fitting of the active contours during systole and diastole. To evaluate the approach, ultrasound image sequences from 30 patients were submitted to the procedure. The images were stored on an international data grid repository that consists of three international sites: Image Processing and Informatics (IPI) Laboratory at University of Southern California, USA; InCor (Heart Institute) at Sao Paulo, Brazil, and Hong Kong Polytechnic University, Hong Kong. The three chosen sites are connected with high speed international networks including the Internet2, and the Brazilian National Research and Education Network (RNP2). The Data Grid was used to store, backup, and share the ultrasound images and analysis results, which provided a large-scale and a virtual data system. In order to study the variability between the automatic and manual definition of artery boundaries, the pooled mean and the standard deviation for the difference between measurements of lumen diameter were computed. The coefficient of variation and correlation were also calculated. For the studied population the difference between manual and automatic measurement of the lumen diameter (LD) and intima-media-thickness (IMT) were 0.12 +/-0.10 and 0.09+/- 0.06, respectively.

  18. Gastric Wall Thickness and the Choice of Linear Staples in Laparoscopic Sleeve Gastrectomy: Challenging Conventional Concepts.

    Science.gov (United States)

    Abu-Ghanem, Yasmin; Meydan, Chanan; Segev, Lior; Rubin, Moshe; Blumenfeld, Orit; Spivak, Hadar

    2017-03-01

    Little evidence is available on the choice of linear staple reloads in laparoscopic sleeve gastrectomy (LSG). Previous literature recommends matching closed staple height (CSH) to tissue-thickness (TT) to avoid ischemia. Our objective was to examine feasibility and safety of "tight" hemostatic (CSH/TT <1) stapling and map the entire gastric wall TT in LSG patients. Prospectively collected outcomes on 202 consecutive patients who underwent LSG with tight order of staples (Ethicon Endosurgery) in this order: pre-pylorus-black (CSH = 2.3 mm), antrum-green (CSH = 2.0 mm), antrum/body-blue (CSH = 1.5 mm), and white (CSH = 1.0 mm) on the body and fundus. Measurements of entire gastric wall TT were made on the first 100 patients' gastric specimens with an electronic-dogmatic indicator. Study included 147 females and 55 males with a mean age of 41.5 ± 11.9 years and body mass index of 41.5 ± 3.8 kg/m(2). Gastric wall measurements revealed mean CSH/TT ratio <1, decreasing from 0.7 ± 0.1 at pre-pylorus to 0.5 ± 0.1 at the fundus. There were 3.1% mechanical failures, mainly (68%) at pre-pylorus-black reloads. Post-operative bleeding occurred in 5 (2.5%) patients. There were no leaks or clinical evidence of sleeve ischemia. Stepwise regression analysis revealed that body mass index (P < 0.001), hypertension (P < 0.01), and male gender (P < 0.001) were associated with increased gastric TT. Our study suggests that reloads with CSH/TT <1 in LSG including staples with CSH of 1 mm on body and fundus are safe. The results challenge the concept that tight stapling cause's ischemia. Since tight reloads are designed to improve hemostasis, their application could have clinical benefit.

  19. Wall thickness measurement using resonant phenomena of circumferential Lamb waves generated by plural transducer elements located evenly on girth

    Science.gov (United States)

    Nishino, Hideo; Iwata, Kodai; Ishikawa, Masashi

    2016-07-01

    We present a novel method of measuring the pipe wall thickness using the resonance of the circumferential (C-) Lamb wave generated by a piezoelectric ring-shaped sensor (PS). The PS is a special device for an axially propagating torsional wave; however, the C-Lamb waves are generated simultaneously as spurious signals owing to the structure of the PS. Particularly under resonant conditions, the C-Lamb waves are dominantly generated, distorting the axially propagating wave. In this method, these troublesome spurious signals are used effectively for the measurement of the wall thickness under the PS location that is a dead zone of the PS itself. The method can compensate for its drawback, namely, the dead zone problem, without using additional instruments. In this study, the mechanisms of the generation and resonance of the C-Lamb waves were first explained. Secondly, the principle of the wall thickness estimation utilizing the resonance of the C-Lamb waves was proposed. Finally, experimental verifications were carried out. The estimated wall thicknesses agreed very well (maximum 1.5% error) with those measured by a micrometer caliper under suitable resonant conditions.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-03-01

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

  1. A borehole stability study by newly designed laboratory tests on thick-walled hollow cylinders

    Directory of Open Access Journals (Sweden)

    S.S. Hashemi

    2015-10-01

    Full Text Available At several mineral exploration drilling sites in Australia, weakly consolidated formations mainly consist of sand particles that are poorly bonded by cementing agents such as clay, iron oxide cement or calcite. These formations are being encountered when drilling boreholes to the depth of up to 200 m. To study the behaviour of these materials, thick-walled hollow cylinder (TWHC and solid cylindrical synthetic specimens were designed and prepared by adding Portland cement and water to sand grains. The effects of different parameters such as water and cement contents, grain size distribution and mixture curing time on the characteristics of the samples were studied to identify the mixture closely resembling the formation at the drilling site. The Hoek triaxial cell was modified to allow the visual monitoring of grain debonding and borehole breakout processes during the laboratory tests. The results showed the significance of real-time visual monitoring in determining the initiation of the borehole breakout. The size-scale effect study on TWHC specimens revealed that with the increasing borehole size, the ductility of the specimen decreases, however, the axial and lateral stiffnesses of the TWHC specimen remain unchanged. Under different confining pressures the lateral strain at the initiation point of borehole breakout is considerably lower in a larger size borehole (20 mm compared to that in a smaller one (10 mm. Also, it was observed that the level of peak strength increment in TWHC specimens decreases with the increasing confining pressure.

  2. Reduction of the residual stresses in cold expanded thick-walled cylinders by plastic compression

    Institute of Scientific and Technical Information of China (English)

    V.F. SKVORTSOV; A.O. BOZNAK; A.B. KIM; A. Yu ARLYAPOV; A.I. DMITRIEV

    2016-01-01

    We suppose that in order to maintain high accuracy of holes and to lower residual stresses after cold expansion of thick-walled cylinders, which undergo cross-section plastic deformation, it is necessary to perform axial plastic compression and subsequent cold expansion with small interferences. To test this hypothesis, we studied hoop, radial and axial residual stresses in cylinders made of carbon steel AISI 1050 with hole diameter of 5 mm, outer diameter of 15 mm and length of 30 mm by Sachs method as well as accuracy of expanded holes. It is found that double cold expansion with total interference equal to 5.1%generates hoop residual stresses with largest absolute value equal to 284 MPa and ensures high holes accuracy (IT7). After plastic compression with strain equal to 0.5 and 1%the mentioned stresses reduced to 120 and 75 MPa respectively, and accuracy of the holes reduced as well. Subsequent cold expansion with small interference equal to 0.9%helps to restore holes accuracy (IT7) gained by double cold expansion and ensure that absolute value of hoop residual stresses (177 MPa) is lower compared to double cold expansion.

  3. ELASTOPLASTIC ANALYSIS OF THICK-WALL CYLINDER CONSIDERING THE MATERIAL'S DILATANCY CHARACTER

    Institute of Scientific and Technical Information of China (English)

    江崎哲郎; 张铭; 竹下昭博; 三谷泰浩

    1995-01-01

    Impermeable bentonite or its mixtures have been proposed as candidate materials to be used in the geotechnical disposal of radioactive nuclear waste. These materials are filled in the space between a canister containing radioactive nuclear waste and an underground chamber to absorb the radionuclide emitting from the canister and simultaneously retard its migration accompanying the permeation of underground water to prevent the surrounding environment from pollution. On the basis of the established elastoplastic strain-hardening mechanical model considering the material's dilatancy character, the authors carry out the stress-strain analysis of a thick-wall cylinder in a plane strain state subjected to a pressure difference between internal and external pressures. The analysis may be expected to be a theoretical basis for developing a coupled shear and permeability test apparatus for conducting a permeability test along a sheared plane in a specimen. The apparatus will be used to study the effects of shear strain on the variation of geotechnical materials′ permeability coefficient in order to evaluate the influence of shear strain caused by nonuniform deformation and/or earthquake on the long-term safety of the disposal system of radioactive nuclear waste. The theoretical analysis methods in this paper can be directly spread to the analysis of the deformation and stability of tunnels or roadways driven in soft soils or high moisture-bearing soft rocks.

  4. STATIONARY PROBLEM OF MOISTURE-INDUCED ELASTICITY OF HETEROGENEOUS THICK-WALLED CYLINDERS

    Directory of Open Access Journals (Sweden)

    Andreev Vladimir Igorevich

    2012-10-01

    Full Text Available Many problems of identification of the stress-strain state against the background of the heat and mass transfer are solved through the application of constant (averaged values of mechanical properties (elastic modulus, Poisson's ratio and derivation of differential equations with constant coefficients. Due to irregular distribution of temperature and other factors of impact, including the moisture content, mechanical properties of many materials change significantly; therefore, the problems in question are solved within the framework of mechanics of heterogeneous bodies. In this paper, the authors solve the classical problem of the steady-state moisture-induced elasticity of a thick-walled cylinder by taking account of the changes in the value of the elastic modulus caused by the influence of moisture. In this case, the problem is reduced to a differential equation with variable coefficients, which makes the solution more complicated though more accurate. It is proven that due regard for the heterogeneity leads to a significant increase in stresses, if compared to the solution based on the mean values of the modulus of elasticity.

  5. Optimum heating of thick-walled pressure components assuming a quasi-steady state of temperature distribution

    Science.gov (United States)

    Dzierwa, Piotr; Trojan, Marcin; Taler, Dawid; Kamińska, Katarzyna; Taler, Jan

    2016-08-01

    As a result of the development of wind farms, the gas — steam blocks, which shall quickly ensure energy supply in case the wind velocity is too low, are introduced to the energy system. To shorten the start-up time of the gas — steam and conventional blocks, the structure of the basic components of the blocks are changed, e.g. by reducing the diameter of the boiler, the thickness of its wall is also reduced. The attempts were also made to revise the currently binding TRD 301 regulations, replacing them by the EN 12952-3 European Standard, to reduce the allowable heating and cooling rates of thick walled boiler components. The basic assumption, on which the boiler regulations allowing to calculate the allowable temperature change rates of pressure components were based, was the quasi — steady state of the temperature field in the simple shaped component, such as a slab, cylindrical or spherical wall.

  6. Current-induced domain wall motion in Co/Ni nano-wires with different Co and Ni thicknesses

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, K; Chiba, D; Koyama, T; Yamada, G; Ono, T [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011 (Japan); Tanigawa, H; Fukami, S; Suzuki, T; Ohshima, N; Ishiwata, N [NEC Corporation, 1120 Shimokuzawa, Chuo-ku, Sagamihara, Kanagawa 252-5298 (Japan); Nakatani, Y, E-mail: ono@scl.kyoto-u.ac.jp [University of Electro-communications, Chofu, Tokyo, 182-8585 (Japan)

    2011-01-01

    The authors have investigated magnetic domain wall motion induced by electric currents in ferromagnetic nano-wires made of Co/Ni multilayers. The thicknesses of Co and Ni layers were changed, whereas the numbers of layer stacks of Co and Ni were the same in all samples. The sample with thinner total Co/Ni thickness showed the lower threshold current density for the domain wall motion as an overall trend, which is qualitatively in agreement with the expectation by the theory based on the adiabatic spin-transfer model. The lowest threshold current density was 2.9x10{sup 11} A/m{sup 2} obtained in the sample with the total Co/Ni thickness of 3.4 nm and the wire width of 110 nm.

  7. [Laparoscopic treatment of abdominal wall hernias: prosthesis material comparison].

    Science.gov (United States)

    Biondi, A; Tropea, A; Monaco, N; Musmeci, G; Basile, G; Basile, F

    2011-12-01

    Hernia is due to abdominal wall weakening. This allows the contents of the abdomen to protrude from normal boundaries. Hernias are repaired by implanting a sterile surgical mesh to strengthen the weakened abdominal wall. Aim of this study is to compare the results obtained by bard Composix® L/P mesh or Dualmesh Plus Gore® implanting. The mesh has various beneficial characteristics. It is a reinforcing material for the abdominal wall, even when in the direct contact with the intestinal tract does not cause adhsion problems. The use of biocompatible materials is necessary in laparoscopic hernia repair. e-PTFE prosthesis and Dual Mesh® were the first to be used for laparoscopic treatment of the abdominal wall defects. These prosthesis are the result of many improvements, actually they are 1-mm thick and the two surfaces have different characteristics. Compound meshes are composed by e-PTFE and polypropylene with different percentage of the two materials and methods of interactions. The incidence of early complications were poor in relation to both types of implants, only seroma cases e-PTFE treated showed a prevalence of complication, in agreement with literature. About relapses in our experience we found that e-PTFE cases were predominantly. Dual Mesh® has better adaptability than Bard Composix®, which allows easier placement of the prosthesis as well as a better adaptation to the wall surface. The Bard Composix®, thanks to rigidity due to the polypropylene component has better handling than the Dual Mesh®, as it promotes a rapid and easy deployment of the prosthesis inside the abdominal cavity, favoring its positioning. The use of both prosthesis depends also on the experience specific to each operator, moreover, a rigorous surgical technique remains fundamental for the application of the mesh used.

  8. Pressure-induced wall thickness variations in multi-layered wall of a pollen tube and Fourier decomposition of growth oscillations.

    Science.gov (United States)

    Pietruszka, Mariusz; Haduch-Sendecka, Aleksandra

    2015-04-01

    The augmented growth equation introduced by Ortega is solved for the apical portion of the pollen tube as an oscillating volume, which we approach in the framework of a two-fluid model in which the two fluids represent the constant pressure and the fluctuating features of the system. Based on routine Fourier analysis, we calculate the energy spectrum of the oscillating pollen tube, and discuss the resonant frequency problem of growth rate oscillations. We also outline a descriptive model for cell wall thickness fluctuations associated with small, yet regular variations (~ 0.01 MPa) observed in turgor pressure. We propose that pressure changes must lead to the sliding of wall layers, indirectly resulting in a wave of polarization of interlayer bonds. We conclude that pollen tube wall thickness may oscillate due to local variations in cell wall properties and relaxation processes. These oscillations become evident because of low amplitude/high frequency pressure fluctuations δP being superimposed on turgor pressure P. We also show that experimentally determined turgor pressure oscillates in a strict periodical manner. A solitary frequency f0 ≈ 0.066 Hz of these (~ 0.01 MPa in magnitude) oscillations for lily pollen tubes was established by the discrete Fourier transform and Lorentz fit.

  9. Reproducibility of Gadolinium Enhancement Patterns and Wall Thickness in Hypertrophic Cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Granillo, Gaston A., E-mail: grodriguezgranillo@gmail.com; Deviggiano, Alejandro; Capunay, Carlos; Zan, Macarena C. De; Carrascosa, Patricia [Department of Cardiovascular Imaging - Diagnóstico Maipú, Buenos Aires (Argentina)

    2016-07-15

    Reproducibility data of the extent and patterns of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) is limited. To explore the reproducibility of regional wall thickness (WT), LGE extent, and LGE patterns in patients with HCM assessed with cardiac magnetic resonance (CMR). The extent of LGE was assessed by the number of segments with LGE, and by the total LV mass with LGE (% LGE); and the pattern of LGE-CMR was defined for each segment. A total of 42 patients (672 segments) with HCM constituted the study population. The mean WT measurements showed a mean difference between observers of -0.62 ± 1.0 mm (6.1%), with limits of agreement of 1.36 mm; -2.60 mm and intraclass correlation coefficient (ICC) of 0.95 (95% CI 0.93-0.96). Maximum WT measurements showed a mean difference between observers of -0.19 ± 0.8 mm (0.9%), with limits of agreement of 1.32 mm; -1.70 mm, and an ICC of 0.95 (95% CI 0.91-0.98). The % LGE showed a mean difference between observers of -1.17 ± 1.2 % (21%), with limits of agreement of 1.16%; -3.49%, and an ICC of 0.94 (95% CI 0.88-0.97). The mean difference between observers regarding the number of segments with LGE was -0.40 ± 0.45 segments (11%), with limits of agreement of 0.50 segments; -1.31 segments, and an ICC of 0.97 (95% CI 0.94-0.99). The number of segments with LGE might be more reproducible than the percent of the LV mass with LGE.

  10. Reproducibility of Gadolinium Enhancement Patterns and Wall Thickness in Hypertrophic Cardiomyopathy

    Science.gov (United States)

    Rodriguez-Granillo, Gaston A.; Deviggiano, Alejandro; Capunay, Carlos; Zan, Macarena C. De; Carrascosa, Patricia

    2016-01-01

    Background Reproducibility data of the extent and patterns of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) is limited. Objective To explore the reproducibility of regional wall thickness (WT), LGE extent, and LGE patterns in patients with HCM assessed with cardiac magnetic resonance (CMR). Methods The extent of LGE was assessed by the number of segments with LGE, and by the total LV mass with LGE (% LGE); and the pattern of LGE-CMR was defined for each segment. Results A total of 42 patients (672 segments) with HCM constituted the study population. The mean WT measurements showed a mean difference between observers of -0.62 ± 1.0 mm (6.1%), with limits of agreement of 1.36 mm; -2.60 mm and intraclass correlation coefficient (ICC) of 0.95 (95% CI 0.93-0.96). Maximum WT measurements showed a mean difference between observers of -0.19 ± 0.8 mm (0.9%), with limits of agreement of 1.32 mm; -1.70 mm, and an ICC of 0.95 (95% CI 0.91-0.98). The % LGE showed a mean difference between observers of -1.17 ± 1.2 % (21%), with limits of agreement of 1.16%; -3.49%, and an ICC of 0.94 (95% CI 0.88-0.97). The mean difference between observers regarding the number of segments with LGE was -0.40 ± 0.45 segments (11%), with limits of agreement of 0.50 segments; -1.31 segments, and an ICC of 0.97 (95% CI 0.94-0.99). Conclusions The number of segments with LGE might be more reproducible than the percent of the LV mass with LGE. PMID:27305110

  11. Reproducibility of Gadolinium Enhancement Patterns and Wall Thickness in Hypertrophic Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Gaston A. Rodriguez-Granillo

    2016-01-01

    Full Text Available Abstract Background: Reproducibility data of the extent and patterns of late gadolinium enhancement (LGE in hypertrophic cardiomyopathy (HCM is limited. Objective: To explore the reproducibility of regional wall thickness (WT, LGE extent, and LGE patterns in patients with HCM assessed with cardiac magnetic resonance (CMR. Methods: The extent of LGE was assessed by the number of segments with LGE, and by the total LV mass with LGE (% LGE; and the pattern of LGE-CMR was defined for each segment. Results: A total of 42 patients (672 segments with HCM constituted the study population. The mean WT measurements showed a mean difference between observers of -0.62 ± 1.0 mm (6.1%, with limits of agreement of 1.36 mm; -2.60 mm and intraclass correlation coefficient (ICC of 0.95 (95% CI 0.93-0.96. Maximum WT measurements showed a mean difference between observers of -0.19 ± 0.8 mm (0.9%, with limits of agreement of 1.32 mm; -1.70 mm, and an ICC of 0.95 (95% CI 0.91-0.98. The % LGE showed a mean difference between observers of -1.17 ± 1.2 % (21%, with limits of agreement of 1.16%; -3.49%, and an ICC of 0.94 (95% CI 0.88-0.97. The mean difference between observers regarding the number of segments with LGE was -0.40 ± 0.45 segments (11%, with limits of agreement of 0.50 segments; -1.31 segments, and an ICC of 0.97 (95% CI 0.94-0.99. Conclusions: The number of segments with LGE might be more reproducible than the percent of the LV mass with LGE.

  12. Effect of Heat Flux on Creep Stresses of Thick-Walled Cylindrical Pressure Vessels

    Directory of Open Access Journals (Sweden)

    Mosayeb Davoudi Kashkoli

    2014-06-01

    Full Text Available Assuming that the thermo-creep response of the material is governed by Norton’s law, an analytical solution is presented for the calculation of time-dependent creep stresses and displacements of homogeneous thick-walled cylindrical pressure vessels. For the stress analysis in a homogeneous pressure vessel, having material creep behavior, the solutions of the stresses at a time equal to zero (i.e. the initial stress state are needed. This corresponds to the solution of materials with linear elastic behavior. Therefore, using equations of equilibrium, stress-strain and strain-displacement, a differential equation for displacement is obtained and then the stresses at a time equal to zero are calculated. Using Norton’s law in the multi-axial form in conjunction with the above-mentioned equations in the rate form, the radial displacement rate is obtained and then the radial, circumferential and axial creep stress rates are calculated. When the stress rates are known, the stresses at any time are calculated iteratively. The analytical solution is obtained for the conditions of plane strain and plane stress. The thermal loading is as follows: inner surface is exposed to a uniform heat flux, and the outer surface is exposed to an airstream. The heat conduction equation for the one-dimensional problem in polar coordinates is used to obtain temperature distribution in the cylinder. The pressure, inner radius and outer radius are considered constant. Material properties are considered as constant. Following this, profiles are plotted for the radial displacements, radial stress, circumferential stress and axial stress as a function of radial direction and time.

  13. A Study on the Void Formation in Residual Wall Thickness of Fluid-Assisted Injection Molding Parts

    Directory of Open Access Journals (Sweden)

    Hyung-Pil Park

    2014-01-01

    Full Text Available In fluid-assisted injection molding, the distribution of the residual wall thickness on the inside and outside of the curved area is different, and void is formed due to the effect of the shrinkage on the outside where the residual wall thickness is thicker. The shrinkage that takes place in the residual wall is affected by the rheological changes in the polymer caused by temperature change and also by the thermal properties of the penetration fluid. In this study, the different effects on void formation in residual wall during fluid-assisted injection molding were analyzed, and water and silicone oil that had different thermal properties were used for the fluids. For this, heat transfer analysis and injection molding analysis were conducted. The void formation occurred due to the different temperature distribution and volumetric shrinkage in the direction of the residual wall in the curved area with a hollow section. It was also found that the void formation in the curved area decreased in the case of silicone oil compared to the case of water from simulation and experiments.

  14. Bobbin-Tool Friction-Stir Welding of Thick-Walled Aluminum Alloy Pressure Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Dalder, E C; Pastrnak, J W; Engel, J; Forrest, R S; Kokko, E; Ternan, K M; Waldron, D

    2007-06-06

    It was desired to assemble thick-walled Al alloy 2219 pressure vessels by bobbin-tool friction-stir welding. To develop the welding-process, mechanical-property, and fitness-for-service information to support this effort, extensive friction-stir welding-parameter studies were conducted on 2.5 cm. and 3.8 cm. thick 2219 Al alloy plate. Starting conditions of the plate were the fully-heat-treated (-T62) and in the annealed (-O) conditions. The former condition was chosen with the intent of using the welds in either the 'as welded' condition or after a simple low-temperature aging treatment. Since preliminary stress-analyses showed that stresses in and near the welds would probably exceed the yield-strength of both 'as welded' and welded and aged weld-joints, a post-weld solution-treatment, quenching, and aging treatment was also examined. Once a suitable set of welding and post-weld heat-treatment parameters was established, the project divided into two parts. The first part concentrated on developing the necessary process information to be able to make defect-free friction-stir welds in 3.8 cm. thick Al alloy 2219 in the form of circumferential welds that would join two hemispherical forgings with a 102 cm. inside diameter. This necessitated going to a bobbin-tool welding-technique to simplify the tooling needed to react the large forces generated in friction-stir welding. The bobbin-tool technique was demonstrated on both flat-plates and plates that were bent to the curvature of the actual vessel. An additional issue was termination of the weld, i.e. closing out the hole left at the end of the weld by withdrawal of the friction-stir welding tool. This was accomplished by friction-plug welding a slightly-oversized Al alloy 2219 plug into the termination-hole, followed by machining the plug flush with both the inside and outside surfaces of the vessel. The second part of the project involved demonstrating that the welds were fit for the intended

  15. Effect of mortar joint thickness on deformability in medieval stone walls

    Directory of Open Access Journals (Sweden)

    Cassinello, M. J.

    2006-12-01

    Full Text Available An analysis of the stone walls in Gothic cathedrals revealed that Medieval master builders varied mortar joint thicknesses from one structural member to another. This fact, which has gone largely unnoticed to date, has a considerable impact on the structural behavior of cathedrals,due to its direct effect on two fundamental parameters,deformability and strength. In the absence offield data, an experimental test program was conducted at the INTEMAC Central Laboratory to determine the possible variations in deformability of Medieval masonry with changes in joint mortar thickness in the range found in the structural members of Spanish Gothic cathedrals. The results obtained show —further to an observation by Eduardo Torroja— that mortar joints are a determinant in the structural behavior of masonry. The modulus of deformation varied from 169.7 to 5,632.7 N/mm2at joint thicknesses ranging from 17.00 to 5.50 mm. Structural models should be adapted to accommodate this behavior pattern via parametric sensitivity analysis to obtain a clearer understanding of structural behaviour in Gothic cathedrals.El análisis desarrollado sobre las fábricas pétreas de las catedrales góticas revela que los maestros medievales utilizaron diferentes espesores de juntas de mortero en cada uno de sus elementos estructurales. Este hecho —no tenido en cuenta hasta la fecha— tiene una gran repercusión en el comportamiento estructural de la catedral,ya que influye directamente en sus parámetros fundamentales: deformabilidad y resistencia. Dada la inexistencia de datos, realizamos un programa experimental de ensayos en el laboratorio central de INTEMAC, para establecerlos posibles rangos de variabilidad de la deformabilidad de las fábricas medievales en función de la variabilidad del espesor del mortero de juntas que detectamos en los diferentes elementos estructurales de las catedrales góticas españolas. Los resultados obtenidos demuestran

  16. Finite-element modelling of low-temperature autofrettage of thick-walled tubes of the austenitic stainless steel AISI 304 L: Part II. Thick-walled tube with cross-bore

    Science.gov (United States)

    Feng, H.; Donth, B.; Mughrabi, H.

    1998-01-01

    In part I, the autofrettage of a smooth thick-walled tube of the austenitic stainless steel AISI 304 L was studied by finite-element (FE) modelling. It was shown that low- temperature autofrettage is more efficient than autofrettage at room temperature, since it produces a larger beneficial compressive residual tangential (hoop) stress at the inner bore of the tube and hence permits a more significant enhancement of the fatigue resistance against pulsating internal pressure. The objective of the present study (part II) was to investigate the technically more relevant case of a thick-walled tube with a cross-bore made of the same steel. For this purpose, three-dimensional FE calculations were performed in order to characterize the influences of the autofrettage pressure and temperature on the stress and strain changes, in particular at the site of the cross-bore, also taking into account the effects of work hardening and reverse yielding. The results indicate that low-temperature autofrettage can also be applied advantageously in the case of thick-walled tubes with a cross-bore by virtue of the significantly larger residual compressive stresses, compared to room temperature autofrettage. From the quantitative FE calculations, the optimal combination of autofrettage temperature and pressure were concluded to lie in the range of 0965-0393/6/1/007/img1 to 0965-0393/6/1/007/img2, respectively. The calculated results were found to be in fair agreement with the measured values.

  17. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output

    DEFF Research Database (Denmark)

    Smerup, Morten Holdgaard; Damkjær, Mads; Brøndum, Emil

    2016-01-01

    to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End......-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke...

  18. Quantification of myocardial delayed enhancement and wall thickness in hypertrophic cardiomyopathy: Multidetector computed tomography versus magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lei [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd Beijing (China); Ma, Xiaohai, E-mail: maxi8238@gmail.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd Beijing (China); Feuchtner, Gudrun Maria [Department of Radiology II, Innsbruck Medical University, Innsbruck (Austria); Zhang, Chen; Fan, Zhanming [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, No. 2 Anzhen Rd Beijing (China)

    2014-10-15

    Objectives: To evaluate the accuracy of multidetector computed tomography (MDCT) in assessing myocardial delayed enhancement and left ventricle wall thickness in hypertrophic cardiomyopathy (HCM) compared with cardiac magnetic resonance (CMR) as the reference standard. Materials and methods: Eighty consecutive patients (59 male; 53.2 ± 13.0 years) were examined with MDCT, followed by CMR 1 day later. Cardiac CT angiography and a delayed CT were performed. CMR was performed according to a standardized protocol. Left ventricle wall thickness and positions of myocardial delayed enhancement were identified in both CMR and CT images according to the American Heart Association left ventricle 17-segment model. Myocardial delayed enhancement was characterized as “dense” (areas with clear defined borders) or “diffuse” and then quantified using both techniques. Results: Left ventricle wall thickness determined by MDCT was significantly correlated with CMR (R = 0.88, P < 0.01). Compared with CMR, MDCT accurately diagnosed 74 of 78 (94.9%) patients and 1243 of 1326 (93.7%) segments. For dense myocardial delayed enhancement, MDCT significantly correlated with CMR (R = 0.88, P < 0.01) and slightly underestimated myocardial delayed enhancement (mean, −3.85%; lower and upper limits of agreement, −13.40% and 5.70%, respectively). Conclusions: MDCT provides reliable quantification of myocardial delayed enhancement and evaluation of left ventricle wall thickness and has a good correlation with CMR in patients with HCM when a comprehensive cardiac CT protocol is used and can be applied for intervention planning.

  19. Exact and Numerical Elastic Analysis for the FGM Thick-Walled Cylindrical Pressure Vessels with Exponentially-Varying Properties

    Directory of Open Access Journals (Sweden)

    Nejad M. Zamani

    2016-09-01

    Full Text Available Assuming exponential-varying properties in the radial direction and based on the elasticity theory, an exact closed-form analytical solution is obtained to elastic analysis of FGM thick-walled cylindrical pressure vessels in the plane strain condition. Following this, radial distribution of radial displacement, radial stress, and circumferential stress are plotted for different values of material inhomogeneity constant. The displacements and stresses distributions are compared with the solutions of the finite element method (FEM.

  20. Using The Descending Aortic Wall Thickness Measured In Transesophageal Echocardiography As A Risk Marker For Aortic Dissection

    Directory of Open Access Journals (Sweden)

    Zaher Fanari

    2015-04-01

    Full Text Available Objective: The aim of this study is to estimate whether aortic wall thickness is increased in patients with Aortic dissection (AD compared to low risk control group and can be used in addition to aortic diameter as a risk marker of AD. Background: AD occurs due to pathologies that may increase thickness of the aortic wall. Transesophageal echocardiography (TEE has the ability to visualise both the thoracic aortic wall and lumen. Aortic diameter has been used to predict aortic dissection and timing of surgery, but it is not always predictive of that risk. Methods: In 48 patients with AD who underwent TEE were examined retrospectively and compared to 48 control patients with patent foramen ovale (PFO. We measured aortic diameter at different levels, intimal/medial thickness (IMT and complete wall thickness (CMT. Demographic data and cardiovascular risk factors were reviewed. The data was analysed using ANOVA and student t test. Results: (AD patients were older [mean age 66 AD vs. 51 PFO], had more hypertension, diabetes, hyperlipidemia and Coronary artery disease. Both IMT and CMT in the descending aorta were increased in AD group [(1.85 vs. 1.43 mm; P=0.03 and 2.93 vs. 2.46 mm; p=0.01. As expected the diameter of ascending aorta was also greater in AD (4.61 vs. 2.92 cm; P=0.004. Conclusions: CMT and IMT in the descending aorta detected by TEE is greater in patients with AD when compared to control and may add prognostic data to that of aortic diameter

  1. Airway wall thickness of allergic asthma caused by weed pollen or house dust mite assessed by computed tomography.

    Science.gov (United States)

    Liu, Liping; Li, Guangrun; Sun, Yuemei; Li, Jian; Tang, Ningbo; Dong, Liang

    2015-03-01

    Little was known about Airway wall thickness of asthma patients with different allergen allergy. So we explored the possible difference of Airway wall thickness of asthma patients mono-sensitized to weed pollen or HDM using high-resolution computed tomography. 85 severe asthma patients were divided into weed pollen group and HDM group according to relevant allergen. 20 healthy donors served as controls. Airway wall area, percentage wall area and luminal area at the trunk of the apical bronchus of the right upper lobe were quantified using HRCT and compared. The values of pulmonary function were assessed as well. There were differences between HDM group and weed pollen group in WA/BSA,WA% and FEF25-75% pred, and no significant difference in FEV1%pred, FEV1/FVC and LA/BSA. In weed pollen group, WA/BSA was observed to correlate with the duration of rhinitis, whereas in HDM group, WA/BSA and LA/BSA was observed to correlate with the duration of asthma. In weed pollen group, FEV1/FVC showed a weak but significant negative correlation with WA%, but in HDM group FEV1/FVC showed a significant positive correlation with WA% and a statistical negative correlation with LA/BSA. FEV1/FVC and FEF25-75% pred were higher and WA/BSA and LA/BSA were lower in healthy control group than asthma group. FEV1%pred and WA% was no significant difference between asthma patients and healthy subjects. There are differences between HDM mono-sensitized subjects and weed pollen mono-sensitized subjects, not only in airway wall thickness, but also small airway obstruction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Stoichiometry, Length, and Wall Thickness Optimization of TiO2 Nanotube Array for Efficient Alcohol Sensing.

    Science.gov (United States)

    Hazra, A; Bhowmik, B; Dutta, K; Chattopadhyay, P P; Bhattacharyya, P

    2015-05-13

    The present study concerns development of an efficient alcohol sensor by controlling the stoichiometry, length, and wall thickness of electrochemically grown TiO2 nanotube array for its use as the sensing layer. Judicious variation of H2O content (0, 2, 10 and 100% by volume) in the mixed electrolyte comprising ethylene glycol and NH4F resulted into the desired variation of stoichiometry. The sensor study was performed within the temperature range of 27 to 250 °C for detecting the alcohols in the concentration range of 10-1000 ppm. The nanotubes grown with the electrolyte containing 2 vol % H2O offered the maximum response magnitude. For this stoichiometry, variation of corresponding length (1.25-2.4 μm) and wall thickness (19.8-9 nm) of the nanotubes was achieved by varying the anodization time (4-16 h) and temperatures (42-87 °C), respectively. While the variation of length influenced the sensing parameters insignificantly, the best response magnitude was achieved for ∼13 nm wall thickness. The underlying sensing mechanism was correlated with the experimental findings on the basis of structural parameters of the nanotubes.

  3. Determination of Optimum Thermal Insulation Thicknesses for External Walls Considering the Heating, Cooling and Annual Energy Requirement

    Directory of Open Access Journals (Sweden)

    Ömer KAYNAKLI

    2016-06-01

    Full Text Available In this study, optimization of thermal insulation thickness applied to the external walls of buildings has been carried out comparatively based on the seasonal (space-heating and cooling and the annual energy requirements considering solar radiation effect. This study has been performed for four degree-day regions of Turkey, namely, Iskenderun (in the first region, Istanbul (in the second region, Ankara (in the third region and Ardahan (in the fourth region. By determining the sol-air temperatures for each region and maximizing the present worth value of seasonal and annual energy savings, the optimum thermal insulation thicknesses have been calculated. The effects of solar radiation on heating-cooling energy requirements, the variation of optimum insulation thicknesses and payback periods with respect to degree-day regions, the differences between the analyses based on seasonal and annual have been presented in tabular and graphical form.

  4. Thickened wall-type GB cancer and complicated cholecystitis : comparison of CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seong Nim; Jung, Hae Jong; Kang, Sung Hag; Shin, Sung Ran; Lee, Min Jin; Lee, Kil Jun; Lee, Sang Chun [Seoul Red Cross Hospital, Seoul (Korea, Republic of)

    1996-11-01

    We compared CT findings of thickened wall-type gallbladder cancer with those of complicated cholecystitis. We retrospectively reviewed abdominal CT scans of ten patients with thickened wall-type gallbladder cancer and eight patients with complicated cholecystitis, from March 1991 to November 1995. CT findings of thickened wall-type gallbladder cancer showed diffuse or focal wall thickening. Wall thickness was 5.3-18.0mm (mean value, 12.2mm;n=10). Gallbladder wall thickness of complicated cholecystitis was 3.0-14.0mm (mean value, 6.6mm;n=8). Statistical significance was noted between thickened wall-type gallbladder cancer and complicated cholecytitis(p<0.0029). Irregular wall thickening was noted in 7/10 cases of thickened wall-type gallbladder cancer(70%). Regular wall thickening was noted in 6/8 cases of complicated cholecystitis(75%). The luminal diameter of thickened wall-type gallbladder cancer was 3.3-5.4cm (mean value, 4.2cm; n=10). The luminal diameter of complicated cholecystitis was 5.2-8.0cm (mean value, 6.5cm; n=8). Statistical significance was noted between thickened wall-type gallbladder cancer and complicated cholecystitis(p<0.0003). The halo sign was noted in only 3/8 cases of complicated cholecystitis(38%). Secondary findings of thickened wall-type gallbladder caner was lymphadenopathy in 3/10 cases(30%), and liver invasion in 2/10 cases(20%). Secondary findings of complicated cholecystitis were liver abscess in 2/8 cases(25%), and RLQ abdominal fluid collection and pleural effusion in 4/8 cases(50%). Differential factors of thickened wall-type gallbladder cancer from complicated cholecystits are gallbladder wall thickness, regularity of wall thickness, halo sign, secondary findings and luminal distention.

  5. Detailed Dynamic Heat Transfer in Thick Brick Walls Typical of Lille Metropolis

    Directory of Open Access Journals (Sweden)

    Antczak E.

    2012-10-01

    Full Text Available The study of thermal transfer in old houses massive walls offers a big interest permitting the understanding of their specificities and the choice of a suitable material for their eventual insulation. We propose to study the thermal transfer in massive brick walls that characterize the Northern Europe old houses. To do so, we will begin by defining the thermal transfer mode: we proved that the transfer mode can be reduced to a unidirectional transfer. Then, an experimental wall is built and submitted to two different solicitation types (constant temperature in steady state mode and sinusoidal temperature through a wooden insulated box containing a radiator. The interest of these solicitations is to determine the thermal properties of the wall: the steady-state regime permits to determine the thermal resistances of the system when the harmonic regime permits to determine the thermal capacities of the system.

  6. Filled and empty states of carbon nanotubes in water: Dependence on nanotube diameter, wall thickness and dispersion interactions

    Indian Academy of Sciences (India)

    Malay Rana; Amalendu Chandra

    2007-09-01

    We have carried out a series of molecular dynamics simulations of water containing a narrow carbon nanotube as a solute to investigate the filling and emptying of the nanotube and also the modifications of the density and hydrogen bond distributions of water inside and also in the vicinity of the outer surfaces of the nanotube. Our primary goal is to look at the effects of varying nanotube diameter, wall thickness and also solute-solvent interactions on the solvent structure in the confined region also near the outer surfaces of the solute. The thickness of the walls is varied by considering single and multi-walled nanotubes and the interaction potential is varied by tuning the attractive strength of the 12-6 pair interaction potential between a carbon atom of the nanotubes and a water molecule. The calculations are done for many different values of the tuning parameter ranging from fully Lennard-Jones to pure repulsive pair interactions. It is found that both the solvation characteristics and hydrogen bond distributions can depend rather strongly on the strength of the attractive part of the solute-water interaction potential. The thickness of the nanotube wall, however, is found to have only minor effects on the density profiles, hydrogen bond network and the wetting characteristics. This indicates that the long range electrostatic interactions between water molecules inside and on the outer side of the nanotube do not make any significant contribution to the overall solvation structure of these hydrophobic solutes. The solvation characteristics are primarily determined by the balance between the loss of energy due to hydrogen bond network disruption, cavity repulsion potential and offset of the same by attractive component of the solute-water interactions. Our studies with different system sizes show that the essential features of wetting and dewetting characteristics of narrow nanotubes for different diameter and interaction potentials are also present in

  7. Large-scale, thick, self-assembled, nacre-mimetic brick-walls as fire barrier coatings on textiles

    Science.gov (United States)

    Das, Paramita; Thomas, Helga; Moeller, Martin; Walther, Andreas

    2017-01-01

    Highly loaded polymer/clay nanocomposites with layered structures are emerging as robust fire retardant surface coatings. However, time-intensive sequential deposition processes, e.g. layer-by-layer strategies, hinders obtaining large coating thicknesses and complicates an implementation into existing technologies. Here, we demonstrate a single-step, water-borne approach to prepare thick, self-assembling, hybrid fire barrier coatings of sodium carboxymethyl cellulose (CMC)/montmorillonite (MTM) with well-defined, bioinspired brick-wall nanostructure, and showcase their application on textile. The coating thickness on the textile is tailored using different concentrations of CMC/MTM (1–5 wt%) in the coating bath. While lower concentrations impart conformal coatings of fibers, thicker continuous coatings are obtained on the textile surface from highest concentration. Comprehensive fire barrier and fire retardancy tests elucidate the increasing fire barrier and retardancy properties with increasing coating thickness. The materials are free of halogen and heavy metal atoms, and are sourced from sustainable and partly even renewable building blocks. We further introduce an amphiphobic surface modification on the coating to impart oil and water repellency, as well as self-cleaning features. Hence, our study presents a generic, environmentally friendly, scalable, and one-pot coating approach that can be introduced into existing technologies to prepare bioinspired, thick, fire barrier nanocomposite coatings on diverse surfaces.

  8. Automatic airway wall segmentation and thickness measurement for long-range optical coherence tomography images.

    Science.gov (United States)

    Qi, Li; Huang, Shenghai; Heidari, Andrew E; Dai, Cuixia; Zhu, Jiang; Zhang, Xuping; Chen, Zhongping

    2015-12-28

    We present an automatic segmentation method for the delineation and quantitative thickness measurement of multiple layers in endoscopic airway optical coherence tomography (OCT) images. The boundaries of the mucosa and the sub-mucosa layers are accurately extracted using a graph-theory-based dynamic programming algorithm. The algorithm was tested with sheep airway OCT images. Quantitative thicknesses of the mucosal layers are obtained automatically for smoke inhalation injury experiments.

  9. Assessment of maxillary sinus wall thickness with paranasal sinus digital tomosynthesis and CT

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Ji Eun; Shim, Sung Shine; Kim, Yoo Kyung; Kong, Kyoung Ae [Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of)

    2017-05-15

    This study was performed to compare paranasal sinus tomosynthesis with computed tomography (CT) imaging as a radiologic tool to evaluate the paranasal sinuses, using measurement of the soft tissue thickness of the maxillary sinus. A total of 114 patients with sinusitis who underwent both paranasal sinus digital tomosynthesis (DT) and CT were enrolled in this retrospective study. Two observers independently assessed soft tissue thickness in both maxillary sinus chambers using both DT and CT images. The mean difference in soft tissue thickness measured by each observer was −0.31 mm on CT and 0.15 mm on DT. The mean differences in soft tissue thickness measured with DT and CT were −0.15 by observer 1 and −0.31 by observer 2. Evaluation of the agreement in measurement of soft tissue thickness in the maxillary sinus using DT and CT showed a high intraclass correlation, with the 95% limit of agreement ranging from −3.36 mm to 3.06 mm [intraclass correlation coefficient (ICC), 0.994: p<0.01] for observer 1 and from −5.56 mm to 4.95 mm (ICC, 0.984: p<0.01) for observer 2. As an imaging tool, DT is comparable to CT for assessing the soft tissue thickness of maxillary sinuses in patients with sinusitis.

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

    Directory of Open Access Journals (Sweden)

    Ted eBotha

    2013-08-01

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

  11. The gender-specific chest wall thickness prediction equations for routine measurements of {sup 239}Pu and {sup 241}Am within the lungs using HPGE detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vickers, L.R. [Pantex Plant, Amarillo, TX (United States)

    1996-03-01

    The current chest wall thickness prediction equation is not applicable to use in routine lung counting measurements for detection of low energy photons (17-60 keV) within the lungs of male and female subjects. The current chest wall thickness prediction equation was derived for the NaI-CsI {open_quotes}phoswich{close_quotes} detection system, which is not the routine detection system in use; the subject position was supine, which is not the routine position; the equation did not account for the intercostal tissue thicknesses of muscle and adipose which significantly attenuate low energy photons (17-60 keV); it was derived from male subjects only and is used to predict the chest wall thickness of female subjects for whom it is not applicable. The current chest wall thickness prediction equation yields unacceptable percent errors in the HPGe detection efficiency calibration for {sup 239}Pu and {sup 241}Am (17- and 59.5-keV photons, respectively) relative to the gender-specific HPGe chest wall thickness prediction equations of this paper (+284% to -73% for {sup 239}Pu; +42% to -39% for {sup 241}Am). As a result, use of the current chest wall thickness prediction equation yields unacceptable percent errors (proportional in magnitude to the percent errors in the detection efficiency calibration) in the calculation of the minimum detectable activity (Bq) or in an initial assessment of a radioactive contamination exposure detected by a routine lung count measurement. 17 refs., 6 figs., 12 tabs.

  12. Dual stack black blood carotid artery CMR at 3T: Application to wall thickness visualization

    Directory of Open Access Journals (Sweden)

    Marx Nikolaus

    2009-11-01

    Full Text Available Abstract Background The increasing understanding of atherosclerosis as an important risk factor for the development of acute ischemic events like ischemic stroke has stimulated increasing interest in non-invasive assessment of the structure, composition and burden of plaque depositions in the carotid artery wall. Vessel wall imaging by means of cardiovascular magnetic resonance (CMR is conventionally done by 2D dual inversion recovery (DIR techniques, which often fail in covering large volumes of interest as required in plaque burden assessment. Although the technique has been extended to 2D multislice imaging, its straight extension to 3D protocols is still limited by the prolonged acquisition times and incomplete blood suppression. A novel approach for rapid overview imaging of large sections of the carotid artery wall at isotropic spatial resolutions is presented, which omits excitation of the epiglottis. By the interleaved acquisition of two 3D stacks with the proposed motion sensitized segmented steady-state black-blood gradient echo technique (MSDS the coverage of the carotid artery trees on both sides in reasonable scan times is enabled. Results 10 patients were investigated with the proposed technique and compared to conventional transversal DIR turbo spin and gradient echo approaches centered at the height of the carotid bifurcation. In all MSDS experiments sufficient black-blood contrast could be obtained over the entire covered volumes. The contrast to noise ratio between vessel and suppressed blood was improved by 73% applying the motion sensitizing technique. In all patients the suspicious areas of vessel wall thickening could be clearly identified and validated by the conventional local imaging approach. The average assessable vessel wall segment length was evaluated to be 18 cm. While in 50% of the cases motion artifacts could be appreciated in the conventional images, none were detected for the MSDS technique. Conclusion The

  13. Measure Guideline: Incorporating Thick Layers of Exterior Rigid Insulation on Walls

    Energy Technology Data Exchange (ETDEWEB)

    Lstiburek, Joseph [Building Science Corporation, Westford, MA (United States); Baker, Peter [Building Science Corporation, Westford, MA (United States)

    2015-04-01

    This measure guideline provides information about the design and construction of wall assemblies that use layers of rigid exterior insulation thicker than 1-½ inches and that require a secondary cladding attachment location exterior to the insulation. The guideline is separated into several distinct sections that cover: fundamental building science principles relating to the use of exterior insulation on wall assemblies; design principles for tailoring this use to the specific project goals and requirements; and construction detailing to increase understanding about implementing the various design elements.

  14. Measure Guideline. Incorporating Thick Layers of Exterior Rigid Insulation on Walls

    Energy Technology Data Exchange (ETDEWEB)

    Lstiburek, Joseph [Building Science Corporation, Westford, MA (United States); Baker, Peter [Building Science Corporation, Westford, MA (United States)

    2015-04-09

    This measure guideline, written by the U.S. Department of Energy’s Building America team Building Science Corporation, provides information about the design and construction of wall assemblies that use layers of rigid exterior insulation thicker than 1-½ in. and that require a secondary cladding attachment location exterior to the insulation. The guideline is separated into several distinct sections that cover: (1) fundamental building science principles relating to the use of exterior insulation on wall assemblies; (2) design principles for tailoring this use to the specific project goals and requirements; and (3) construction detailing to increase understanding about implementing the various design elements.

  15. Estimation of emission cone wall thickness of Jupiter's decametric radio emission using stereoscopic STEREO/WAVES observations

    Science.gov (United States)

    Panchenko, M.; Rucker, H. O.

    2016-11-01

    Aims: Stereoscopic observations by the WAVES instrument onboard two STEREO spacecraft have been used with the aim of estimating wall thickness of an emission cone of Jovian decametric radio emission (DAM). Methods: Stereoscopic observations provided by STEREO-A and -B facilitate unambiguous recognition of the Jovian DAM in observed dynamic spectra as well as identification of its components (Io DAM or non-Io DAM). The dynamic spectra of radio emissions recorded by STEREO/WAVES have been analyzed using the method of cross-correlation of the radio dynamic spectra. Results: Altogether, 139 radio events, in particular 91 Io- and 48 non-Io-related radio events were observed. The averaged width of the emission cone wall for Io-DAM as well as for non-Io DAM is about 1.1° ± 0.2°. These results are in agreement with previous findings.

  16. Continuous monitoring of the wall thickness of pipelines with ultrasonic waves; Dauerueberwachung der Wanddicke von Rohrleitungen mit Ultraschall

    Energy Technology Data Exchange (ETDEWEB)

    Mueck, Andreas [SONOTEC Ultraschallsensorik Halle GmbH, Halle (Saale) (Germany); Imhof, Dietmar [TUeV NORD MPA GmbH und Co.KG, Leuna (Germany)

    2015-07-01

    Pipelines in industrial plants must be constantly monitored due to occurring erosion and corrosion. The determination of the residual wall thickness is generally carried out with ultrasound. Often, the critical points are difficult to access and the pipes insulated. The preparation and evaluation of a measurement is therefore very costly. The measuring system SONOWALL S ultrasonic probes are firmly attached to the pipeline and installed into isolation. The number and position of the probes can be freely selected. Often, the load is not known exactly why the monitoring of the pipe wall thickness over the entire circumference is necessary. The acoustic coupling to the pipe is done with proven adhesives that do not lose their adhesive strength even under changing ambient temperatures. The connecting cables are housed away up to 20 m in an easily accessible place in a terminal box. There can be done a wall thickness measurement with conventional ultrasonic testing devices. By using standardized components, the measuring system meets the requirements of DIN EN 12668 and DIN EN 14127. [German] Rohrleitungen in industriellen Anlagen muessen aufgrund der auftretenden Erosion und Korrosion permanent ueberwacht werden. Die Bestimmung der Restwanddicke erfolgt in der Regel mit Ultraschall. Oftmals sind die kritischen Stellen schwer zugaenglich und die Rohrleitungen isoliert. Die Vor- und Nachbereitung einer Messung ist dadurch sehr aufwendig. Beim Messsystem SONOWALL S werden Ultraschallpruefkoepfe fest an der Rohrleitung angebracht und in die Isolation eingebaut. Die Anzahl und Position der Pruefkoepfe ist dabei frei waehlbar. Oft ist die Belastung nicht genau bekannt, weshalb eine Ueberwachung der Rohrwanddicke ueber den gesamten Umfang notwendig ist. Die akustische Ankopplung an das Rohr erfolgt mit erprobten Klebstoffen, die auch bei wechselnden Umgebungstemperaturen ihre Haftfestigkeit nicht verlieren. Die Anschlusskabel werden bis zu 20m entfernt an einer gut

  17. 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

  18. Development of automated welding process for field fabrication of thick walled pressure vessels. Fourth quarter technical progress report for period ending September 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    Progress in developing an automated welding process for the field fabrication of thick walled pressure vessels is reported. Plans for the demonstration facility, for nondestructive testing, and for the procurement of materials are discussed. (LCL)

  19. The importance of ultrasonographic measurement of peritoneal wall thickness in pediatric chronic peritoneal dialysis patients.

    Science.gov (United States)

    Yavaşcan, Önder; Aksu, Nejat; Alparslan, Caner; Sarıtaş, Serdar; Elmas, Cengiz Han; Eraslan, Ali Nihat; Duman, Soner; Mir, Sevgi

    2015-04-01

    Loss of peritoneal function due to peritoneal fibrosing syndrome (PFS) is a major factor leading to treatment failure in chronic peritoneal dialysis (PD) patients. Although the precise biologic mechanisms responsible for these changes have not been defined, the general assumption is that alterations in peritoneal function are related to structural changes in the peritoneal membrane. Studies of the peritoneal membrane by non-invasive ultrasonography (US) in chronic PD patients are limited. The aim of the present study is to assess the relationship between functional parameters of peritoneum and peritoneal thickness measured by US in children treated by chronic PD. We recruited two groups of patients: 23 subjects (13 females, 10 males) on chronic PD (patient group) and 26 (7 females, 19 males) on predialysis out-patient follow-up (creatinine clearance: 20-60 mL/min/1.73 m(2)) (control group). Age, sex, weight, height, body mass index (BMI), chronic PD duration, episodes of peritonitis and the results of peritoneal equilibration test (PET) were recorded. Hemoglobin (Hb), blood pressure (BP), left ventricular mass index (LVMI) and renal osteodystrophy (ROD) parameters were also obtained. The thickness of the parietal peritoneum was measured by trans-abdominal US in all children. Statistical analyses were performed by using Student's t and Pearson's correlation tests. Mean peritoneal thickness in chronic PD patients (1028.26 ± 157.26 μm) was significantly higher than control patients (786.52 ± 132.33). Mean peritoneal thickness was significantly correlated with mean body height (R(2) = 0.93, p thickness and Hb, BP, LVMI and ROD parameters. In conclusion, ultrasonographic measurement of peritoneal membrane thickness is a simple and non-invasive method in chronic PD children. This diagnostic tool likely enables to assess peritoneal structure and function in these patients.

  20. INVESTIGATION OF THE INFLUENCE OF MOLD ROTATIONAL SPEED ON THE CAST WALL THICKNESS IN THE ROTATIONAL MOLDING PROCESS

    Directory of Open Access Journals (Sweden)

    Tomasz Jachowicz

    2013-09-01

    Full Text Available This paper presents the rotational molding process. The general principles of this polymer processing technology have been described. The main applications have been introduced and leading advantages and typical disadvantages of rotational molding process have been discussed. Based on the conducted experimental tests, the influence of changing one selected technological parameter, which characterized rotational molding process, on selected geometrical features of the polymer cast has been determined. Rotational mold’s speed around axes was changed and a thickness of cast walls has been measured. Laboratory test stand, processing properties of polymer, also test program and experimental test methodology have been described.

  1. IMPROVED LOCALLY CONFORMAL FINITE-DIFFERENCE TIME-DOMAIN METHOD FOR EDGE INCLINED SLOTS IN A FINITE WALL THICKNESS WAVEGUIDE

    Institute of Scientific and Technical Information of China (English)

    Li Long; Zhang Yu; Liang Changhong

    2004-01-01

    An Improved Locally Conformal Finite-Difference Time-Domain (ILC-FDTD) method is presented in this paper, which is used to analyze the edge inclined slots penetrating adjacent broadwalls of a finite wall thickness waveguide. ILC-FDTD not only removes the instability of the original locally conformal FDTD algorithm, but also improves the computational accuracy by locally modifying magnetic field update equations and the virtual iterative electric fields according to the complexity of the slot fringe fields. The mutual coupling between two edge inclined slots can also be analyzed by ILC-FDTD effectively.

  2. Limit analysis of viscoplastic thick-walled cylinder and spherical shell under internal pressure using a strain gradient plasticity theory

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Plastic limit load of viscoplastic thick-walled cylinder and spherical shell subjected to internal pressure is investigated analytically using a strain gradient plastic-itv theory. As a result, the current solutions can capture the size effect at the micron scale. Numerical results show that the smaller the inner radius of the cylinder or spherical shell, the more significant the scale effects. Results also show that the size effect is more evident with increasing strain or strain-rate sensitivity index. The classical plastic-based solutions of the same problems are shown to be a special case of the present solution.

  3. Measurement of arterial wall thickness as a surrogate marker for atherosclerosis

    NARCIS (Netherlands)

    de Groot, E; Hovingh, GK; Wiegman, A; Duriez, P; Smit, AJ; Fruchart, JC; Kastelein, JJP

    2004-01-01

    Large observational studies and atherosclerosis regression trials of lipid-modifying pharmacotherapy have established that intima-media thickness of the carotid and femoral arteries, as measured noninvasively by B-mode ultrasound, is a valid surrogate marker for the progression of atherosclerotic di

  4. Thick growing multilayer nanobrick wall thin films: super gas barrier with very few layers.

    Science.gov (United States)

    Guin, Tyler; Krecker, Michelle; Hagen, David Austin; Grunlan, Jaime C

    2014-06-24

    Recent work with multilayer nanocoatings composed of polyelectrolytes and clay has demonstrated the ability to prepare super gas barrier layers from water that rival inorganic CVD-based films (e.g., SiOx). In an effort to reduce the number of layers required to achieve a very low oxygen transmission rate (OTR (layer-by-layer (LbL) assembly. Buffering the chitosan solution and its rinse with 50 mM Trizma base increased the thickness of these films by an order of magnitude. The OTR of a 1.6-μm-thick, six-bilayer film was 0.009 cc/m(2)·day·atm, making this the best gas barrier reported for such a small number of layers. This simple modification to the LbL process could likely be applied more universally to produce films with the desired properties much more quickly.

  5. Instrumented thick-walled tube method for measuring thermal pressure in fluids and isotropic stresses in thermosetting resins

    Science.gov (United States)

    Merzlyakov, Mikhail; Simon, Sindee L.; McKenna, Gregory B.

    2005-06-01

    We have developed a method for measuring the thermal pressure coefficient and cure-induced and thermally induced stresses based on an instrumented thick-walled tube vessel. The device has been demonstrated at pressures up to 330 MPa and temperatures to 300 °C. The method uses a sealed stainless steel thick-walled tube to impose three-dimensional isotropic constraints. The tube is instrumented with strain gauges in hoop and in axial directions and can be used in open or closed configurations. By making measurements of the isotropic stresses as a function of temperature, the method allows determination of the thermal pressure coefficient in both the glassy and rubbery (or liquid) states. The method also can be used to measure isotropic stress development in thermosetting resins during cure and subsequent thermal cycling. Experimental results are presented for sucrose benzoate, di-2-ethylhexylsebacate, and an epoxy resin. The current report shows that the method provides reliable estimates for the thermal pressure coefficient. The thermal pressure coefficient is determined with resolution on the order of 10kPa/K. Among advantages of the method is that the tubes are reusable, even when measurements are made for cure response of thermosetting resins.

  6. Thermoelastic Analysis of a Functionally Graded Rotating Thick-Walled Tube Subjected to Mechanical and Thermal Loads

    Science.gov (United States)

    Xin, Libiao; Yang, Shengyou; Ma, Baoyu; Dui, Guansuo

    2015-11-01

    A thermoelastic solution for the functionally graded rotating thick-walled tube subjected to axisymmetric mechanical and thermal loads is given in terms of volume fractions of constituents. We assume that the tube consists of two linear elastic constituents and the volume fraction of one phase is a power function varied in the radial direction. By using the assumption of a uniform strain field within the representative volume element, the theoretical solutions of the displacement and the stresses are presented. Based on the relation of the volume average stresses of constituents and the macroscopic stresses of the composite material in micromechanics, the present method can avoid the assumption of the distribution regularities of unknown overall material parameters appeared in existing papers, such as Young's modulus, thermal expansion coefficient, thermal conductivity, and density. The effects of the angular velocity, the volume fraction, the ratio of two thermal expansion coefficients, the ratio of two thermal conductivities, and the ratio of two densities on the displacement and stresses are systematically studied, which should help structural engineers and material scientists optimally design thick-walled tube comprised inhomogeneous materials.

  7. Analytical Solution for Interference Fit for Multi-Layer Thick-Walled Cylinders and the Application in Crankshaft Bearing Design

    Directory of Open Access Journals (Sweden)

    Jun Qiu

    2016-06-01

    Full Text Available Interference fit is an important contact mode used for torque transmission existing widely in engineering design. To prevent trackslip, a certain magnitude of interference has to be ensured; meanwhile, the interference needs to be controlled to avoid failure of the mechanical components caused by high assembly stress. The finite element method (FEM can be used to analyze the stress, while the computational cost of FEM involving nonlinear contact algorithm is relatively high, and likely to come across low precision and convergence problems. Therefore, a rapid and accurate analytical method for estimation is of vital need, especially for the initial design stage when the parameters vary in a large range. In this study, an analytical method to calculate the contact pressure and stress between multi-layer thick-walled cylinders (MLTWC with multi-contact pairs and temperature-raising effect is proposed, and evaluated by FEM. The analytical solution of the interference for tri-layer thick-walled cylinders is applied to the design of engine crankshaft bearing. The results indicate that the analytical method presented in this study can reduce complexity of MLTWC problems and improve the computational efficiency. It is well suited to be used for the calculation model of parameter optimization in early design.

  8. Collapse Pressure Analysis of Transversely Isotropic Thick-Walled Cylinder Using Lebesgue Strain Measure and Transition Theory

    Directory of Open Access Journals (Sweden)

    A. K. Aggarwal

    2014-01-01

    Full Text Available The objective of this paper is to provide guidance for the design of the thick-walled cylinder made up of transversely isotropic material so that collapse of cylinder due to influence of internal and external pressure can be avoided. The concept of transition theory based on Lebesgue strain measure has been used to simplify the constitutive equations. Results have been analyzed theoretically and discussed numerically. From this analysis, it has been concluded that, under the influence of internal and external pressure, circular cylinder made up of transversely isotropic material (beryl is on the safer side of the design as compared to the cylinders made up of isotropic material (steel. This is because of the reason that percentage increase in effective pressure required for initial yielding to become fully plastic is high for beryl as compared to steel which leads to the idea of “stress saving” that reduces the possibility of collapse of thick-walled cylinder due to internal and external pressure.

  9. Estimation of PSD Shifts for High-Resolution Metrology of Thickness Micro-Changes with Possible Applications in Vessel Walls and Biological Membrane Characterization

    Directory of Open Access Journals (Sweden)

    Abelardo Ruiz

    2012-11-01

    Full Text Available Achieving accurate measurements of inflammation levels in tissues or thickness changes in biological membranes (e.g., amniotic sac, parietal pleura and thin biological walls (e.g., blood vessels from outside the human body, is a promising research line in the medical area. It would provide a technical basis to study the options for early diagnosis of some serious diseases such as hypertension, atherosclerosis or tuberculosis. Nevertheless, achieving the aim of non-invasive measurement of those scarcely-accessible parameters on patient internal tissues, currently presents many difficulties. The use of high-frequency ultrasonic transducer systems appears to offer a possible solution. Previous studies using conventional ultrasonic imaging have shown this, but the spatial resolution was not sufficient so as to permit a thickness evaluation with clinical significance, which requires an accuracy of a few microns. In this paper a broadband ultrasonic technique, that was recently developed by the authors to address other non-invasive medical detection problems (by integrating a piezoelectric transducer into a spectral measuring system, is extended to our new objective; the aim is its application to the thickness measurement of sub-millimeter membranes or layers made of materials similar to some biological tissues (phantoms. The modeling and design rules of such a transducer system are described, and various methods of estimating overtones location in the power spectral density (PSD are quantitatively assessed with transducer signals acquired using piezoelectric systems and also generated from a multi-echo model. Their effects on the potential resolution of the proposed thickness measuring tool, and their capability to provide accuracies around the micron are studied in detail. Comparisons are made with typical tools for extracting spatial parameters in laminar samples from echo-waveforms acquired with ultrasonic transducers. Results of this advanced

  10. Estimation of PSD Shifts for High-Resolution Metrology of Thickness Micro-Changes with Possible Applications in Vessel Walls and Biological Membrane Characterization

    Science.gov (United States)

    Ramos, Antonio; Bazán, Ivonne; Negreira, Carlos; Brum, Javier; Gómez, Tomás; Calás, Héctor; Ruiz, Abelardo; de la Rosa, José Manuel

    2012-01-01

    Achieving accurate measurements of inflammation levels in tissues or thickness changes in biological membranes (e.g., amniotic sac, parietal pleura) and thin biological walls (e.g., blood vessels) from outside the human body, is a promising research line in the medical area. It would provide a technical basis to study the options for early diagnosis of some serious diseases such as hypertension, atherosclerosis or tuberculosis. Nevertheless, achieving the aim of non-invasive measurement of those scarcely-accessible parameters on patient internal tissues, currently presents many difficulties. The use of high-frequency ultrasonic transducer systems appears to offer a possible solution. Previous studies using conventional ultrasonic imaging have shown this, but the spatial resolution was not sufficient so as to permit a thickness evaluation with clinical significance, which requires an accuracy of a few microns. In this paper a broadband ultrasonic technique, that was recently developed by the authors to address other non-invasive medical detection problems (by integrating a piezoelectric transducer into a spectral measuring system), is extended to our new objective; the aim is its application to the thickness measurement of sub-millimeter membranes or layers made of materials similar to some biological tissues (phantoms). The modeling and design rules of such a transducer system are described, and various methods of estimating overtones location in the power spectral density (PSD) are quantitatively assessed with transducer signals acquired using piezoelectric systems and also generated from a multi-echo model. Their effects on the potential resolution of the proposed thickness measuring tool, and their capability to provide accuracies around the micron are studied in detail. Comparisons are made with typical tools for extracting spatial parameters in laminar samples from echo-waveforms acquired with ultrasonic transducers. Results of this advanced measurement

  11. Portal venous arterialization resulting in increased portal inflow and portal vein wall thickness in rats

    Institute of Scientific and Technical Information of China (English)

    Wen-Gang Li; Yong-Liang Chen; Jing-Xi Chen; Lei Qu; Bin-Dang Xue; Zhi-Hai Peng; Zhi-Qiang Huang

    2008-01-01

    AIM:To explore the influence of portal vein hemodynamic changes after portal venous arterialization(PVA) on peribiliary vascular plexus (PVP)morphological structure and hepatic pathology,and to establish a theoretical basis for the clinical application of PVA.METHODS:Sprague-Dawley rats were randomly divided into control and PVA groups.After PVA,hemodynamic changes of the portal vein and morphological structure of hepatohilar PVP were observed using Doppler ultrasound,liver function tests,ink perfusion transparency management and three-dimensional reconstruction of computer microvisualization,and pathological examination was performed on tissue from the bile duct wall and the liver.RESULTS:After PVA,the cross-sectional area and blood flow of the portal vein were increased,and the increase became more significant over time,in a certain range.If the measure to limit the flow in PVA was not adopted,the high blood flow would lead to dilatation of intrahepatic portal vein and its branches,increase in collagen and fiber degeneration in tunica intima.Except glutamic pyruvic transaminase (GPT),other liver function tests were normal.CONCLUSION:Blood with a certain flow and oxygen content is important for filling the PVP and meeting the oxygen requirement of the bile duct wall.After PVA,It is the anatomic basis to maintain normal morphology of hepatohilar bile duct wall that the blood with high oxygen content and high flow in arterialized portal vein may fill PVP by collateral vessel reflux.A adequate measure to limit blood flow is necessary in PVA.

  12. Analytical solution for the pseudoelastic response of a shape memory alloy thick-walled cylinder under internal pressure

    Science.gov (United States)

    Tabesh, M.; Liu, B.; Boyd, J. G.; Lagoudas, D. C.

    2013-09-01

    Analytical solutions are derived for the isothermal pseudoelastic response of a shape memory alloy (SMA) thick-walled cylinder subjected to internal pressure. The Tresca transformation criterion and linear hardening are used. Equations are given for the radial and circumferential stresses, transformation strains and radial displacement at various steps of loading and unloading. A structural pressure-temperature phase diagram is provided for the cylinder, analogous to the stress-temperature phase diagram of SMA materials. Pressurization of an initially 100% austenitic cylinder causes the martensite to initially form at the inner radius. For a relatively thin-walled cylinder the transformation front reaches the outer radius before the transformation has completed at the inner radius, whereas for a thick-walled cylinder the transformation completes at the inner radius while there is still an outer ring of 100% austenite. For a given OD/ID ratio, a critical temperature is derived that stipulates which of these two cases occurs. An analytical result is provided for the pressure that will cause the transformation to complete at the inner radius. During unloading, the reverse transformation can start at either the inner or the outer surface of the cylinder and can propagate outward and then reverse its direction and propagate back to the inner surface. The effect of martensitic transformation on the structural yield strength due to plasticity is also investigated and it is shown that the pressure required to initiate yielding can be substantially decreased or increased depending on the temperature and the state of transformation achieved, even though the yield stress of the material is independent of temperature. Finally, the effectiveness of the Tresca transformation criterion to derive closed-form solutions for this problem is demonstrated by comparing with finite element solutions using the von Mises theory.

  13. SU-C-BRA-04: Use of Esophageal Wall Thickness in Evaluation of the Response to Chemoradiation Therapy for Esophageal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J; Kligerman, S; Lu, W [University of Maryland School of Medicine, Baltimore, MD (United States); Kang, M [University of Maryland School of Medicine, Baltimore, MD (United States); Yeungnam University Medical Center, Daegu (Korea, Republic of)

    2015-06-15

    Purpose: To quantitatively evaluate the esophageal cancer response to chemoradiation therapy (CRT) by measuring the esophageal wall thickness in CT. Method: Two datasets were used in this study. The first dataset is composed of CT scans of 15 esophageal cancer patients and 15 normal controls. The second dataset is composed of 20 esophageal cancer patients who underwent PET/CT scans before (Pre-CRT) and after CRT (Post-CRT). We first segmented the esophagus using a multi-atlas-based algorithm. The esophageal wall thickness was then computed, on each slice, as the equivalent circle radius of the segmented esophagus excluding the lumen. To evaluate the changes of wall thickness, we computed the standard deviation (SD), coefficient of variation (COV, SD/Mean), and flatness [(Max–Min)/Mean] of wall thickness along the entire esophagus. Results: For the first dataset, the mean wall thickness of cancer patients and normal controls were 6.35 mm and 6.03 mm, respectively. The mean SD, COV, and flatness of the wall thickness were 2.59, 0.21, and 1.27 for the cancer patients and 1.99, 0.16, and 1.13 for normal controls. Statistically significant differences (p < 0.05) were identified in SD and flatness. For the second dataset, the mean wall thickness of pre-CRT and post-CRT patients was 7.13 mm and 6.84 mm, respectively. The mean SD, COV, and flatness were 1.81, 0.26, and 1.06 for pre-CRT and 1.69, 0.26, and 1.06 for post-CRT. Statistically significant difference was not identified for these measurements. Current results are based on the entire esophagus. We believe significant differences between pre- and post-CRT scans could be obtained, if we conduct the measurements at tumor sites. Conclusion: Results show thicker wall thickness in pre-CRT scans and differences in wall thickness changes between normal and abnormal esophagus. This demonstrated the potential of esophageal wall thickness as a marker in the tumor CRT response evaluation. This work was supported in part by

  14. Different Transition Mechanisms and Tunable Wall Thicknesses of Block Copolymer Vesicles

    Science.gov (United States)

    Xiao, Mengying; Wang, Rong; Xie, Daiqian

    2013-03-01

    By using dissipative particle dynamics, we studied how to control the two pathways for vesicle-formation mechanism considering the hydrophobic/hydrophilic block ratio, polymer-solvent interaction, and polymer concentration. A crucial balance between the segregation of inner-hydrophobic beads and the attraction of outer-hydrophilic beads drastically affects the self-assembly pathways of amphiphilic block copolymer into vesicles from one mechanism over the other. And during the transition period between these two pathways, vesicles are formed through an in-between pathway. In addition, we have evaluated the thickness of the hydrophobic layer and observed two types of dependence on the vesicle size. Our results indicate that as the degree of hydrophobicity of the blocks increases, from the whole strong behavior to the whole weak behavior relationship, the transformation is observed in large sized vesicles first and then in small sized vesicles. Two characteristics, the chain compaction of the vesicles and the area densities of inner corona, are thought to be important in controlling the membrane thickness. Acknowledgments.This work has been supported by NNSFC (Nos. 20874046, 21074053 and 21133006) and NBRPC (No. 2010CB923303).

  15. Transient Response of a Fluid-Filled, Thick-Walled Spherical Shell Embedded in an Elastic Medium

    Directory of Open Access Journals (Sweden)

    Bahari Ako

    2016-01-01

    Full Text Available The paper addresses the problem of transient elastodynamics analysis of a thick-walled, fluid-filled spherical shell embedded in an elastic medium with an analytical approach. This configuration is investigated at first step for a full-space case. Different constitutive relations for the elastic medium, shell material and filling fluid can be considered, as well as different excitation sources (including S/P wave or plane/spherical incident wave at different locations. With mapmaking visualisation, the wave propagation phenomena can be described and better understood. The methodology is going to be applied to analysis of the tunnels or other shell like structures under the effect of nearby underground explosion.

  16. How do hypertrophic cardiomyopathy mutations affect myocardial function in carriers with normal wall thickness? Assessment with cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Pinto Yigal M

    2010-03-01

    Full Text Available Abstract Background Clinical data on myocardial function in HCM mutation carriers (carriers is sparse but suggests that subtle functional abnormalities can be measured with tissue Doppler imaging before the development of overt hypertrophy. We aimed to confirm the presence of functional abnormalities using cardiovascular magnetic resonance (CMR, and to investigate if sensitive functional assessment could be employed to identify carriers. Results 28 carriers and 28 controls were studied. Global left atrial (LA and left ventricular (LV dimensions, segmental peak systolic circumferential strain (SCS and peak diastolic circumferential strain rate (DCSR, as well as the presence of late Gadolinium enhancement (LGE were determined with CMR. Septal and lateral myocardial velocities were measured with echocardiographic tissue Doppler imaging. lv mass and volumes were comparable between groups. Maximal septal to lateral wall thickness ratio (SL ratio was larger in carriers than in controls (1.3 ± 0.2 versus 1.1 ± 0.1, p 1.2 and a peak DCSR -1 was present in 45% of carriers and in none of the controls, yielding a positive predictive value of 100%. Two carriers and 18 controls had a SL ratio 105%.s-1, yielding a negative predictive value of 90%. With multivariate analysis, HCM mutation carriership was an independent determinant of reduced peak SCS and peak DCSR. Conclusions HCM mutation carriership is an independent determinant of reduced peak SCS and peak DCSR when LV wall thickness is within normal limits, and is associated with increased LA volumes and SL ratio. Using SL ratio and peak DCSR has a high accuracy to identify carriers. However, since carriers also display structural abnormalities and focal LGE, we advocate to also evaluate morphology and presence of LGE when screening for carriers.

  17. Fracture behavior of shallow cracks in full-thickness clad beams from an RPV wall section

    Science.gov (United States)

    Keeney, J. A.; Bass, B. R.; McAfee, W. J.

    A testing program is described that utilizes full-thickness clad beam specimens to quantify fracture toughness for shallow cracks in weld material for which metallurgical conditions are prototypic of those found in reactor pressure vessels (RPV's). The beam specimens are fabricated from an RPV shell segment that includes weld, plate and clad material. Metallurgical factors potentially influencing fracture toughness for shallow cracks in the beam specimens include material gradients and material inhomogeneities in welded regions. The shallow-crack clad beam specimens showed a significant loss of constraint similar to that of other shallow-crack single-edge notch bend (SENB) specimens. The stress-based Dodds-Anderson scaling model appears to be effective in adjusting the test data to account for in-plane loss of constraint for uniaxially tested beams, but cannot predict the observed effects of out-of-plane biaxial loading on shallow-crack fracture toughness. A strain-based dual-parameter fracture toughness correlation (based on plastic zone width) performed acceptably when applied to the uniaxial and biaxial shallow-crack fracture toughness data.

  18. Wall irregularity rather than intima-media thickness is associated with nearby atherosclerosis.

    Science.gov (United States)

    Graf, Iulia M; Schreuder, Floris H B M; Hameleers, Jeroen M; Mess, Werner H; Reneman, Robert S; Hoeks, Arnold P G

    2009-06-01

    In addition to intima-media thickness (IMT), IMT inhomogeneity may carry information about atherosclerosis progression. In 147 vascular diseased patients (mean 66 y, 48% male), we determined the carotid bulb stenosis degree based on local Doppler blood flow velocities. Common carotid artery (CCA) morphologic characteristics, i.e. IMT, IMT-inhomogeneity (intraregistration variation) and IMT uni- and bilateral intrasubject variation (DeltaIMT), were measured using multiple M-mode. Associations of morphologic characteristics, stenosis degree and Framingham score were evaluated with Pearson correlation (r) and multiple regression analysis. The IMT distributions for subjects without and with stenosis were not similar. The stenosis degree score correlated significantly to unilateral (r=0.68) and bilateral DeltaIMT (r=0.62), IMT (r=0.41) and IMT-inhomogeneity (r=0.45). The averaged IMT and IMT-inhomogeneity increased slightly for singular stenosis and abruptly for multiple stenoses. Mean uni- and bilateral DeltaIMT per stenosis degree increased linearly with this degree, reaching a correlation close to 1 (r=0.98 and r=0.97). Interestingly, the majority of the subjects with a moderate to severe bulb stenosis exhibited a carotid IMT lower than the considered critical threshold of 0.9 mm. In conclusion, although CCA is not prone to plaques, its morphologic characteristics are positively correlated with stenosis degree score and other risk scores. DeltaIMT can be more reliable derived from inter-registration rather than from intra-registration variation. In the CCA, DeltaIMT substantiates vascular alteration better than IMT.

  19. Endothelial wall thickness, cardiorespiratory fitness and inflammatory markers in obese and non-obese adolescents

    Directory of Open Access Journals (Sweden)

    Larissa R. Silva

    2014-03-01

    Full Text Available Background: Increased carotid intima-media thickness (c-IMT is considered a marker of early-onset atherosclerosis and it has been found in obese children and adolescents, but the risk factors associated with this population remain to be elucidated. Objective : To compare and verify the relationship between c-IMT, metabolic profile, inflammatory markers, and cardiorespiratory fitness in obese and non-obese children and adolescents. Method : Thirty-five obese subjects (19 boys and 18 non-obese subjects (9 boys, aged 10-16 years, were included. Anthropometry, body composition, blood pressure, maximal oxygen consumption (VO2max, and basal metabolic rate were evaluated. Serum glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR, blood lipids, C-reactive protein (CRP, and adiponectin were assessed. c-IMT was measured by ultrasound. Results: The results showed that c-IMT, triglycerides, insulin, HOMA-IR, and CRP values were significantly higher in the obese group than in the non-obese group, and high-density lipoprotein cholesterol (HDL-c, adiponectin, and VO2max values were significantly lower in the obese group than in the non-obese group. The c-IMT was directly correlated with body weight, waist circumference, % body fat, and HOMA-IR and inversely correlated with % free fat mass, HDL-c, and VO2max. Conclusions : Our findings show that c-IMT correlates not only with body composition, lipids, insulin resistance, and inflammation but also with low VO2max values in children and adolescents.

  20. To Estimate the Axial Elastic Modulus of Eye and Posterior Wall Thickness in Healthy Human Eye by Ultrasound Images and their Relation with Age and Gender

    Directory of Open Access Journals (Sweden)

    S. Shahbazi

    2007-06-01

    Full Text Available Introduction: Based on the invasive studies it has been shown that factors such as age, the progress of eye disorders, lens fibers compression and the biochemical changes of ocular matrix alter the physical characteristics and elastic properties of eye. In this study, a noninvasive method of estimating human eye elasticityis proposed and its relation with age and gender is evaluated using ultrasound images. Materials and Methods: To estimate eye elasticity, an especial loading system was designed and an external stress of 2614 ± 146 Pa which is less than the intraocular pressure of eye was applied to 20 eyes in an in vivo study. The pressure was measured using digital force gauge. The ultrasound images of B-mode were acquired prior to and post applying the stress. For the offline study throughout the loading process, the ultrasound images were saved as multi-frames into the computer by video grabber board. Monitoring, saving and further study of images were provided for the extraction of eye axial length and posterior wall thickness (PWT. The elasticity was estimated by measuring the relative changes of the axial length of eye, the posterior wall thickness and the applied stress. The statistical correlation of elastic modulus was analyzed based on age and gender. Results: The elastic modulus of the eye and the posterior wall thickness was estimated to be 51,777 ± 27304 and 14603 ± 4636 Pa, respectively. The obtained results indicated that there was no significant difference between the elastic parameters of the eye and the posterior wall thickness based on gender in both male and female group. The correlation analysis of the elastic parameter showed that there was significant difference between the eye and the posterior wall thickness based on age with a 95% confidence interval. Discussion and Conclusion: Based on the results obtained in this study the ultrasonic instruments might be used to estimate the hardness of eye lesions as well as eye

  1. STUDY ON EFFECTS TO SHAFT WALL DEFORMATIONS AND FAILURES INDUCED BY LAYER'S CONSOLIDATION DUE TO WATER WTI~HDRAWAL OF EXTRA-THICK UNCONSOLIDATED AQUIFERS

    Institute of Scientific and Technical Information of China (English)

    GENGDeyong; XUYanchun; SHENBaohong

    1995-01-01

    Accordance with more than 10 shaft wall deformation and failure events in Huang-Huai regions in the east of China, this paper discusses effects to shaft wall deformations and failures induced by layer's consolidation due to water withdrawal of extra-thick unconsolidated aquifers and its further deformation or damage trends, based on data obtained from simultaneous monitoring of both damaged and undamaged shafts, their correspondent unconsolidated layers and atmospheric precipitation etc.for more then 3 years.

  2. Determination of the chest wall thickness as calibration parameter for dosimetric partial-body counting; Bestimmung der Brustwandstaerke als Kalibrierparameter fuer dosimetrische Teilkoerpermessungen

    Energy Technology Data Exchange (ETDEWEB)

    Guen, H. [Fachhochschule Giessen-Friedberg, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz; Karlsruher Institut fuer Technologie, Eggenstein-Leopoldshafen (Germany). Inst. fuer Strahlenforschung; Hegenbart, L. [Karlsruher Institut fuer Technologie, Eggenstein-Leopoldshafen (Germany). Inst. fuer Strahlenforschung; Breckow, J. [Fachhochschule Giessen-Friedberg, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz

    2010-05-15

    The authors describe actual partial body measurements with Phoswich detectors in the in-vivo laboratory of the Institute for Technology in Karlsruhe. The chest wall thickness is estimated from the radio of body weight to body length. This formula includes several uncertainties. The aim of the project was the reduction of the uncertainties of the empirical formula using ultrasonography. This method allows an accuracy of plus or minus 1.1 mm for the determined chest wall thickness. Besides the experimental study several voxel models were used to determine the efficiency of modeled measuring systems. The voxel models reach the same accuracy as the ultrasound method.

  3. Comparison of sea-ice freeboard and thickness distributions from aircraft data and cryosat-2

    DEFF Research Database (Denmark)

    accurate range measurements. During the CryoSat Validation Experiment (CryoVEx) 2011 in the Lincoln Sea, Cryosat-2 underpasses were accomplished with two aircraft, which carried an airborne laser-scanner, a radar altimeter and an electromagnetic induction device for direct sea-ice thickness retrieval. Both...... aircraft flew in close formation at the same time of a CryoSat-2 overpass. This is a study about the comparison of the sea-ice freeboard and thickness distribution of airborne validation and CryoSat-2 measurements within the multi-year sea-ice region of the Lincoln Sea in spring, with respect...

  4. Effects of finite wall thickness and sinusoidal heating on convection in nanofluid-saturated local thermal non-equilibrium porous cavity

    Science.gov (United States)

    Alsabery, A. I.; Chamkha, A. J.; Saleh, H.; Hashim, I.; Chanane, B.

    2017-03-01

    The effects of finite wall thickness and sinusoidal heating on convection in a nanofluid-saturated local thermal non-equilibrium (LTNE) porous cavity are studied numerically using the finite difference method. The finite thickness vertical wall of the cavity is maintained at a constant temperature and the right wall is heated sinusoidally. The horizontal insulated walls allow no heat transfer to the surrounding. The Darcy law is used along with the Boussinesq approximation for the flow. Water-based nanofluids with Cu nanoparticles are chosen for investigation. The results of this study are obtained for various parameters such as the Rayleigh number, periodicity parameter, nanoparticles volume fraction, thermal conductivity ratio, ratio of wall thickness to its height and the modified conductivity ratio. Explanation for the influence of the various above-mentioned parameters on the streamlines, isotherms, local Nusselt number and the weighted average heat transfer is provided with regards to the thermal conductivities of nanoparticles suspended in the pure fluid and the porous medium. It is shown that the overall heat transfer is significantly increased with the relative non-uniform heating. Further, the convection heat transfer is shown to be inhibited by the presence of the solid wall. The results have possible applications in the heat-storage fluid-saturated porous systems and the applications of the high power heat transfer.

  5. Plasma operation with an all metal first-wall: Comparison of an ITER-like wall with a carbon wall in JET

    Science.gov (United States)

    Matthews, G. F.; Jet Efda Contributors; ASDEX-Upgrade Team

    2013-07-01

    Installation of the ITER-like Wall (ILW) in JET, has allowed a direct comparison of operation with all carbon plasma facing components (PFCs) to an all metal beryllium/tungsten first-wall under otherwise nearly identical conditions. The JET results are compared with experience from ASDEX-Upgrade where there was a gradual change to a full tungsten first-wall over an extended period. The scope of this review ranges from experience with machine conditioning, impurities and breakdown to material migration, fuel retention, disruptions, impact on operational space, energy confinement and compatibility with impurity seeding. Significant changes are reported, not only in the physics directly related to plasma-surface interactions but also to the main plasma which is strongly affected in unexpected ways, impacting many aspects of tokamak operation.

  6. Snow thickness retrieval using SMOS satellite data: Comparison with airborne IceBridge and buoy measurements

    Science.gov (United States)

    Maaß, N.; Kaleschke, L.; Tian-Kunze, X.

    2015-12-01

    The passive microwave mission SMOS (Soil Moisture and Ocean Salinity) provides daily coverage of the polar regions and its data have been used to retrieve thin sea ice thickness up to about one meter. In addition, there has been an attempt to retrieve snow thickness over thick Arctic multi-year ice, which is a crucial parameter for the freeboard-based estimation of (thick) sea ice thickness from lidar and radar altimetry. SMOS provides measurements at a frequency of 1.4 GHz (L-band) at horizontal and vertical polarization for a range of incidence angles (0 to 60°). The retrieval of ice or snow parameters from SMOS measurements is based on an emission model that describes the 1.4 GHz brightness temperature of (snow-covered) sea ice as a function of the ice and snow thicknesses and the permittivities of these media, which are mainly determined by ice temperature and salinity and snow density, respectively. In the first attempts to retrieve snow thickness from SMOS data, these parameters were assumed to be constant in the emission model, and the resulting maps were compared with airborne ice and snow thickness measurements taken during NASA's Operation IceBridge mission in spring 2012. The present approach to produce SMOS snow thickness maps is more elaborate. For example, available information on the ice surface temperature from MODIS (MODerate resolution Imaging Spectroradiometer) satellite images or from the IceBridge campaign itself are used, and the ice in the retrieval model is described by temperature and salinity profiles instead of using bulk values. As a first step we have produced (winter/spring) snow thickness maps of the Arctic, from 3-day-averages up to monthly means, using the available SMOS data from 2010 on. Here, we show how our spatial snow thickness distributions compare with IceBridge campaign data in the western Arctic from spring 2011 to 2015. In addition, we show how the temporal evolution of SMOS-retrieved snow thickness compares with snow

  7. Ascending aortic wall cohesion: comparison of bicuspid and tricuspid valves.

    Science.gov (United States)

    Benedik, Jaroslav; Pilarczyk, Kevin; Wendt, Daniel; Indruch, Jiri; Flek, Radek; Tsagakis, Konstantinos; Alaeddine, Savvas; Jakob, Heinz

    2012-01-01

    Objectives. Bicuspid aortic valve (AV) represents the most common form of congenital AV malformation, which is frequently associated with pathologies of the ascending aorta. We compared the mechanical properties of the aortic wall between patients with bicuspid and tricuspid AV using a new custom-made device mimicking transversal aortic wall shear stress. Methods. Between 03/2010 and 07/2011, 190 consecutive patients undergoing open aortic valve replacement at our institution were prospectively enrolled, presenting either with a bicuspid (group 1, n = 44) or a tricuspid (group 2, n = 146) AV. Aortic wall specimen were examined with the "dissectometer" resulting in nine specific aortic-wall parameters derived from tensile strength curves (TSC). Results. Patients with a bicuspid AV showed significantly more calcified valves (43.2% versus 15.8%, P group (P = 0.003, P = 0.02, P = 0.01). We found no difference in the aortic wall cohesion between both groups as revealed by shear stress testing (P = 0.72, P = 0.40, P = 0.41). Conclusion. We observed no differences of TSC in patients presenting with tricuspid or bicuspid AVs. These results may allow us to assume that the morphology of the AV and the pathology of the ascending aorta are independent.

  8. Numerical study of the coupling of two identification methods - thermal and electromagnetic - for the reconstruction of inclusions in thick walls

    Science.gov (United States)

    Le Touz, Nicolas; Dumoulin, Jean; Soldovieri, Francesco

    2016-04-01

    In this numerical study we present an approach allowing introducing a priori information in an identification method of internal thermal properties field for a thick wall using infrared thermography measurements. This method is based on a coupling with an electromagnetic reconstructing method which data are obtained from measurements of Ground Penetrating Radar (GPR) ([1], [2]). This new method aims at improving the accuracy of reconstructions performed by using only the thermal reconstruction method under quasi-periodic natural solicitation ([3], [4]). Indeed, these thermal reconstructions, without a priori information, have the disadvantage of being performed on the entire studied wall. Through the intake of information from GPR, it becomes possible to focus on the internal zones that may contain defects. These areas are obtained by defining subdomains around remarkable points identified with the GPR reconstruction and considered as belonging to a discontinuity. For thermal reconstruction without providing a priori information, we need to minimize a functional equal to a quadratic residue issued from the difference between the measurements and the results of the direct model. By defining search fields around these potential defects, and thus by forcing the thermal parameters further thereof, we provide information to the data to reconstruct. The minimization of the functional is then modified through the contribution of these constraints. We do not seek only to minimize a residue, but to minimize the overall residue and constraints, what changes the direction followed by the optimization algorithm in the space of thermal parameters to reconstruct. Providing a priori information may then allow to obtain reconstruction with higher residues but whose thermal parameters are better estimated, whether for locating potential defects or for the reconstructed values of these parameters. In particular, it is the case for air defects or more generally for defects having a

  9. Analysis of the effect of osteon diameter on the potential relationship of osteocyte lacuna density and osteon wall thickness.

    Science.gov (United States)

    Skedros, John G; Clark, Gunnar C; Sorenson, Scott M; Taylor, Kevin W; Qiu, Shijing

    2011-09-01

    An important hypothesis is that the degree of infilling of secondary osteons (Haversian systems) is controlled by the inhibitory effect of osteocytes on osteoblasts, which might be mediated by sclerostin (a glycoprotein produced by osteocytes). Consequently, this inhibition could be proportional to cell number: relatively greater repression is exerted by progressively greater osteocyte density (increased osteocytes correlate with thinner osteon walls). This hypothesis has been examined, but only weakly supported, in sheep ulnae. We looked for this inverse relationship between osteon wall thickness (On.W.Th) and osteocyte lacuna density (Ot.Lc.N/B.Ar) in small and large osteons in human ribs, calcanei of sheep, deer, elk, and horses, and radii and third metacarpals of horses. Analyses involved: (1) all osteons, (2) smaller osteons, either ≤150 μm diameter or less than or equal to the mean diameter, and (3) larger osteons (>mean diameter). Significant, but weak, correlations between Ot.Lc.N/B.Ar and On.W.Th/On.Dm (On.Dm = osteon diameter) were found when considering all osteons in limb bones (r values -0.16 to -0.40, P < 0.01; resembling previous results in sheep ulnae: r = -0.39, P < 0.0001). In larger osteons, these relationships were either not significant (five/seven bone types) or very weak (two/seven bone types). In ribs, a negative relationship was only found in smaller osteons (r = -0.228, P < 0.01); this inverse relationship in smaller osteons did not occur in elk calcanei. These results do not provide clear or consistent support for the hypothesized inverse relationship. However, correlation analyses may fail to detect osteocyte-based repression of infilling if the signal is spatially nonuniform (e.g., increased near the central canal).

  10. Comparison of sea-ice freeboard and thickness distributions from aircraft data and cryosat-2

    DEFF Research Database (Denmark)

    accurate range measurements. During the CryoSat Validation Experiment (CryoVEx) 2011 in the Lincoln Sea, Cryosat-2 underpasses were accomplished with two aircraft, which carried an airborne laser-scanner, a radar altimeter and an electromagnetic induction device for direct sea-ice thickness retrieval. Both......The only remote sensing technique capable of obtaining sea-ice thickness on basin-scale are satellite altimeter missions, such as the 2010 launched CryoSat-2. It is equipped with a Ku-Band radar altimeter, which measures the height of the ice surface above the sea level. This method requires highly...... aircraft flew in close formation at the same time of a CryoSat-2 overpass. This is a study about the comparison of the sea-ice freeboard and thickness distribution of airborne validation and CryoSat-2 measurements within the multi-year sea-ice region of the Lincoln Sea in spring, with respect...

  11. Effects of Ceramic Fibre Insulation Thickness on Skin Formation and Nodule Characteristics of Thin Wall Ductile Iron Casting

    Science.gov (United States)

    Dhaneswara, D.; Suharno, B.; Nugraha, N. D.; Ariobimo, R. D. S.; Sofyan, N.

    2017-02-01

    Skin formation has become one of the problems in the thin wall ductile iron casting because it will reduce the mechanical properties of the materials. One of the solutions to reduce this skin formation is by using heat insulator to control the cooling rate. One of the insulators used for this purpose is ceramic fibre. In this research, the thickness of the ceramic fibre heat insulator used in the mould was varied, i.e. 50 mm on one side and 37.5 mm on the other side (A), no heat insulator (B), and 37.5 mm on both sides (C). After the casting process, the results were characterized in terms of metallography by using scanning electron microscope (SEM) and tensile test for mechanical properties. The results showed that the skin thickness formed in A is 34.21 μm, 23.38 μm in B, and 27.78 μm in C. The nodule count in A is 541.98 nodule/mm2 (84.7%) with an average diameter of 15.14 μm, 590 nodule/mm2 (86.7%) with an average diameter of 13.18 μm in B, and 549.73 nodule/mm2 (87.2%) with an average diameter of 13.95 μm in C. The average ultimate tensile strength for A was 399 MPa, B was 314 MPa, and C was 415 MPa. Microstructural examination under SEM showed that the materials have a ductile fracture with matrix full of ferrite.

  12. Wall shear stress and near-wall convective transport: Comparisons with vascular remodelling in a peripheral graft anastomosis

    Science.gov (United States)

    Gambaruto, A. M.; Doorly, D. J.; Yamaguchi, T.

    2010-08-01

    Fluid dynamic properties of blood flow are implicated in cardiovascular diseases. The interaction between the blood flow and the wall occurs through the direct transmission of forces, and through the dominating influence of the flow on convective transport processes. Controlled, in vitro testing in simple geometric configurations has provided much data on the cellular-level responses of the vascular walls to flow, but a complete, mechanistic explanation of the pathogenic process is lacking. In the interim, mapping the association between local haemodynamics and the vascular response is important to improve understanding of the disease process and may be of use for prognosis. Moreover, establishing the haemodynamic environment in the regions of disease provides data on flow conditions to guide investigations of cellular-level responses. This work describes techniques to facilitate comparison between the temporal alteration in the geometry of the vascular conduit, as determined by in vivo imaging, with local flow parameters. Procedures to reconstruct virtual models from images by means of a partition-of-unity implicit function formulation, and to align virtual models of follow-up scans to a common coordinate system, are outlined. A simple Taylor series expansion of the Lagrangian dynamics of the near-wall flow is shown to provide both a physical meaning to the directional components of the flow, as well as demonstrating the relation between near-wall convection in the wall normal direction and spatial gradients of the wall shear stress. A series of post-operative follow-up MRI scans of two patient cases with bypass grafts in the peripheral vasculature are presented. These are used to assess how local haemodynamic parameters relate to vascular remodelling at the location of the distal end-to-side anastomosis, i.e. where the graft rejoins the host artery. Results indicate that regions of both low wall shear stress and convective transport towards the wall tend to be

  13. Dune erosion near sea walls: Model-data comparison

    NARCIS (Netherlands)

    Van Geer, P.; De Vries, S.; Van Dongeren, A.; Van Thiel de Vries, J.S.M.

    2012-01-01

    This paper describes the validation of the dune erosion model XBeach with laboratory measurement data of dune erosion in the presence of sea walls and revetments. Simulation results show that the essential dune set back processes are captured by the model and that the measurements at most locations

  14. Development of automated welding process for field fabrication of thick walled pressure vessels. Fourth quarter technical progress report for period ending September 28, 1980

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    Progress is reported in research aimed at optimizing an automated welding process for the field fabrication of thick-walled pressure vessels and for evaluating the welded joints. Information is included on the welding equipment, mechanical control of the process, joint design, filler wire optimization, in-process nondestructive testing of welds, and repair techniques. (LCL)

  15. DETRAINING-RELATED CHANGES IN LEFT VENTRICULAR WALL THICKNESS AND LONGITUDINAL STRAIN IN A YOUNG ATHLETE LIKELY TO HAVE HYPERTROPHIC CARDIOMYOPATHY

    Directory of Open Access Journals (Sweden)

    Cesare de Gregorio

    2012-09-01

    Full Text Available One of the diagnostic criteria in order to differentiate between physiological and pathological left ventricular hypertrophy is the wall thickness reduction after at least 3-month detraining period, which is considered a marker of the athlete's heart. This report describes detraining-related regression of LV hypertrophy and improvement in myocardial deformation in a junior athlete likely to have hypertrophic cardiomyopathy

  16. Comparison of gray matter volume and thickness for analysis of cortical changes in Alzheimer's disease

    Science.gov (United States)

    Liu, Jiachao; Li, Ziyi; Chen, Kewei; Yao, Li; Wang, Zhiqun; Li, Kunchen; Guo, Xiaojuan

    2011-03-01

    Gray matter volume and cortical thickness are two indices of concern in brain structure magnetic resonance imaging research. Gray matter volume reflects mixed-measurement information of cerebral cortex, while cortical thickness reflects only the information of distance between inner surface and outer surface of cerebral cortex. Using Scaled Subprofile Modeling based on Principal Component Analysis (SSM_PCA) and Pearson's Correlation Analysis, this study further provided quantitative comparisons and depicted both global relevance and local relevance to comprehensively investigate morphometrical abnormalities in cerebral cortex in Alzheimer's disease (AD). Thirteen patients with AD and thirteen age- and gender-matched healthy controls were included in this study. Results showed that factor scores from the first 8 principal components accounted for ~53.38% of the total variance for gray matter volume, and ~50.18% for cortical thickness. Factor scores from the fifth principal component showed significant correlation. In addition, gray matter voxel-based volume was closely related to cortical thickness alterations in most cortical cortex, especially, in some typical abnormal brain regions such as insula and the parahippocampal gyrus in AD. These findings suggest that these two measurements are effective indices for understanding the neuropathology in AD. Studies using both gray matter volume and cortical thickness can separate the causes of the discrepancy, provide complementary information and carry out a comprehensive description of the morphological changes of brain structure.

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

    Science.gov (United States)

    Botha, C E J

    2013-01-01

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

  18. A numerical study of multiple adiabatic shear bands evolution in a 304LSS thick-walled cylinder

    Science.gov (United States)

    Liu, Mingtao; Hu, Haibo; Fan, Cheng; Tang, Tiegang

    2017-01-01

    The self-organization of multiple shear bands in a 304L stainless steel(304LSS) thick-walled cylinder (TWC) was numerically studied. The microstructures of material lead to the non-uniform distribution of the local yield stress, which play a key role in the formation of spontaneous shear localization. We introduced a probability factor satisfied the Gaussian distribution into the macroscopic constitutive relationship to describe the non-uniformity of local yield stress. Using the probability factor, the initiation and propagation of multiple shear bands in TWC were numerically replicated in our 2D FEM simulation. Experimental results in the literature indicated that the machined surface at the internal boundary of a 304L stainless steel cylinder provides a work-hardened layer (about 20˜30μm) which has significantly different microstructures from the base material. The work-hardened layer leads to the phenomenon that most shear bands propagate along a given direction, clockwise or counterclockwise. In our simulation, periodical single direction spiral perturbations were applied to describe the grain orientation in the work-hardened layer, and the single direction spiral pattern of shear bands was successfully replicated.

  19. Measurement of defect thickness of the wall thinning defect pipes by lock-in infrared thermography technique

    Science.gov (United States)

    Kim, Kyeongsuk; Kim, Kyungsu; Jung, Hyunchul; Chang, Hosub

    2010-03-01

    Mostly piping which is using for the nuclear power plants are made up of carbon steel pipes. The wall thinning defects occurs by the effect of the flow accelerated corrosion of fluid that flows in carbon steel pipes. The defects could be found on the welding part and anywhere in the pipes. The infrared thermography technique which is one of the non-destructive testing method has used for detecting the defects of various kinds of materials over the years. There is a limitation for measuring the defect of metals that have a big coefficient of thermal diffusion. However, a technique using lock-in method gets over the difficulty. Consequently, the lock-in infrared thermography technique has been applied to the various industry fields. In this paper, the defect thickness of the straight pipe which has an artificial defect the inside of the pipes was measured by using the lock-in infrared thermography technique and the result could be utilized in detecting defects of carbon steel pipes.

  20. Welding for testability: An approach aimed at improving the ultrasonic testing of thick-walled austenitic and dissimilar metal welds

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Sabine; Dugan, Sandra [Materials Testing Institute University of Stuttgart (MPA), Pfaffenwaldring 32, 70569 Stuttgart (Germany); Barth, Martin; Schubert, Frank; Köhler, Bernd [Fraunhofer Institute for Nondestructive Testing, Dresden Branch (IZFP-D), Maria-Reiche-Str. 2, 01109 Dresden (Germany)

    2014-02-18

    Austenitic and dissimilar welds in thick walled components show a coarse grained, dendritic microstructure. Therefore, ultrasonic testing has to deal with beam refraction, scattering and mode conversion effects. As a result, the testing techniques typically applied for isotropic materials yield dissatisfying results. Most approaches for improvement of ultrasonic testing have been based on modeling and improved knowledge of the complex wave propagation phenomena. In this paper, we discuss an alternative approach: is it possible to use a modified welding technology which eliminates the cause of the UT complications, i.e. the large-grained structure of the weld seams? Various modification parameters were tested, including: TIG current pulsing, additional DC and AC magnetic fields, and also additional external vibrations during welding. For all welds produced under different conditions, the grain structure of the weld seam was characterized by optical and GIUM microstructure visualizations on cross sections, wave field propagation measurements, and ultrasonic tests of correct detectability of flaws. The mechanical properties of the welds were also tested.

  1. Comparison of Arctic Sea Ice Thickness from Satellites, Aircraft, and PIOMAS Data

    Directory of Open Access Journals (Sweden)

    Xuanji Wang

    2016-08-01

    Full Text Available In this study, six Arctic sea ice thickness products are compared: the AVHRR Polar Pathfinder-extended (APP-x, ICESat, CryoSat-2, SMOS, NASA IceBridge aircraft flights, and the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS. The satellite products are based on three different retrieval methods: an energy budget approach, measurements of ice freeboard, and the relationship between passive microwave brightness temperatures and thin ice thickness. Inter-comparisons are done for the periods of overlap from 2003 to 2013. Results show that ICESat sea ice is thicker than APP-x and PIOMAS overall, particularly along the north coast of Greenland and Canadian Archipelago. The relative differences of APP-x and PIOMAS with ICESat are −0.48 m and −0.31 m, respectively. APP-x underestimates thickness relative to CryoSat-2, with a mean difference of −0.19 m. The biases for APP-x, PIOMAS, and CryoSat-2 relative to IceBridge thicknesses are 0.18 m, 0.18 m, and 0.29 m. The mean difference between SMOS and CryoSat-2 for 0~1 m thick ice is 0.13 m in March and −0.24 m in October. All satellite-retrieved ice thickness products and PIOMAS overestimate the thickness of thin ice (1 m or less compared to IceBridge for which SMOS has the smallest bias (0.26 m. The spatial correlation between the datasets indicates that APP-x and PIOMAS are the most similar, followed by APP-x and CryoSat-2.

  2. Influence of radiation dose and reconstruction algorithm in MDCT assessment of airway wall thickness: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Cardona, Daniel [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Nagle, Scott K. [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Department of Pediatrics, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Li, Ke; Chen, Guang-Hong, E-mail: gchen7@wisc.edu [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Robinson, Terry E. [Department of Pediatrics, Stanford School of Medicine, 770 Welch Road, Palo Alto, California 94304 (United States)

    2015-10-15

    Purpose: Wall thickness (WT) is an airway feature of great interest for the assessment of morphological changes in the lung parenchyma. Multidetector computed tomography (MDCT) has recently been used to evaluate airway WT, but the potential risk of radiation-induced carcinogenesis—particularly in younger patients—might limit a wider use of this imaging method in clinical practice. The recent commercial implementation of the statistical model-based iterative reconstruction (MBIR) algorithm, instead of the conventional filtered back projection (FBP) algorithm, has enabled considerable radiation dose reduction in many other clinical applications of MDCT. The purpose of this work was to study the impact of radiation dose and MBIR in the MDCT assessment of airway WT. Methods: An airway phantom was scanned using a clinical MDCT system (Discovery CT750 HD, GE Healthcare) at 4 kV levels and 5 mAs levels. Both FBP and a commercial implementation of MBIR (Veo{sup TM}, GE Healthcare) were used to reconstruct CT images of the airways. For each kV–mAs combination and each reconstruction algorithm, the contrast-to-noise ratio (CNR) of the airways was measured, and the WT of each airway was measured and compared with the nominal value; the relative bias and the angular standard deviation in the measured WT were calculated. For each airway and reconstruction algorithm, the overall performance of WT quantification across all of the 20 kV–mAs combinations was quantified by the sum of squares (SSQs) of the difference between the measured and nominal WT values. Finally, the particular kV–mAs combination and reconstruction algorithm that minimized radiation dose while still achieving a reference WT quantification accuracy level was chosen as the optimal acquisition and reconstruction settings. Results: The wall thicknesses of seven airways of different sizes were analyzed in the study. Compared with FBP, MBIR improved the CNR of the airways, particularly at low radiation dose

  3. High vancomycin MICs within the susceptible range in Staphylococcus aureus bacteraemia isolates are associated with increased cell wall thickness and reduced intracellular killing by human phagocytes.

    Science.gov (United States)

    Falcón, Rocío; Martínez, Alba; Albert, Eliseo; Madrid, Silvia; Oltra, Rosa; Giménez, Estela; Soriano, Mario; Vinuesa, Víctor; Gozalbo, Daniel; Gil, María Luisa; Navarro, David

    2016-05-01

    Vancomycin minimum inhibitory concentrations (MICs) at the upper end of the susceptible range for Staphylococcus aureus have been associated with poor clinical outcomes of bloodstream infections. We tested the hypothesis that high vancomycin MICs in S. aureus bacteraemia isolates are associated with increased cell wall thickness and suboptimal bacterial internalisation or lysis by human phagocytes. In total, 95 isolates were evaluated. Original vancomycin MICs were determined by Etest. The susceptibility of S. aureus isolates to killing by phagocytes was assessed in a human whole blood assay. Internalisation of bacterial cells by phagocytes was investigated by flow cytometry. Cell wall thickness was evaluated by transmission electron microscopy. Genotypic analysis of S. aureus isolates was performed using a DNA microarray system. Vancomycin MICs were significantly higher (P=0.006) in isolates that were killed suboptimally (killing index 70%) and tended to correlate inversely (P=0.08) with the killing indices. Isolates in both killing groups were internalised by human neutrophils and monocytes with comparable efficiency. The cell wall was significantly thicker (P=0.03) in isolates in the low killing group. No genotypic differences were found between the isolates in both killing groups. In summary, high vancomycin MICs in S. aureus bacteraemia isolates were associated with increased cell wall thickness and reduced intracellular killing by phagocytes.

  4. Chest wall thickness and decompression failure: A systematic review and meta-analysis comparing anatomic locations in needle thoracostomy.

    Science.gov (United States)

    Laan, Danuel V; Vu, Trang Diem N; Thiels, Cornelius A; Pandian, T K; Schiller, Henry J; Murad, M Hassan; Aho, Johnathon M

    2016-04-01

    Current Advanced Trauma Life Support guidelines recommend decompression for thoracic tension physiology using a 5-cm angiocatheter at the second intercostal space (ICS) on the midclavicular line (MCL). High failure rates occur. Through systematic review and meta-analysis, we aimed to determine the chest wall thickness (CWT) of the 2nd ICS-MCL, the 4th/5th ICS at the anterior axillary line (AAL), the 4th/5th ICS mid axillary line (MAL) and needle thoracostomy failure rates using the currently recommended 5-cm angiocatheter. A comprehensive search of several databases from their inception to July 24, 2014 was conducted. The search was limited to the English language, and all study populations were included. Studies were appraised by two independent reviewers according to a priori defined PRISMA inclusion and exclusion criteria. Continuous outcomes (CWT) were evaluated using weighted mean difference and binary outcomes (failure with 5-cm needle) were assessed using incidence rate. Outcomes were pooled using the random-effects model. The search resulted in 34,652 studies of which 15 were included for CWT analysis, 13 for NT effectiveness. Mean CWT was 42.79 mm (95% CI, 38.78-46.81) at 2nd ICS-MCL, 39.85 mm (95% CI, 28.70-51.00) at MAL, and 34.33 mm (95% CI, 28.20-40.47) at AAL (P=.08). Mean failure rate was 38% (95% CI, 24-54) at 2nd ICS-MCL, 31% (95% CI, 10-64) at MAL, and 13% (95% CI, 8-22) at AAL (P=.01). Evidence from observational studies suggests that the 4th/5th ICS-AAL has the lowest predicted failure rate of needle decompression in multiple populations. Level 3 SR/MA with up to two negative criteria. Therapeutic. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness

    Science.gov (United States)

    Carvalho, Ana; Nabais, Cristina; Vieira, Joana; Rossi, Sergio; Campelo, Filipe

    2015-01-01

    The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs) are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD) or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT) in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010–2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate. PMID:26305893

  6. Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness.

    Science.gov (United States)

    Carvalho, Ana; Nabais, Cristina; Vieira, Joana; Rossi, Sergio; Campelo, Filipe

    2015-01-01

    The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs) are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD) or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT) in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010-2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate.

  7. Ancient Indians (Harappan settlement) were aware of tsunami/storm protection measures: A new interpretation of thick walls at Dholavira, Gujarat, India

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Dubey, R.; Saraswat, R.; Sundaresh; Gaur, A.S.; Loveson, V.J.

    -urbanization preceded abandon- ment in stage VII (1500–1450 BCE)2. The Dholavira fortalice is unique. The architectural framework comprises citadel (castle + bailey), middle town and lower town (Figure 2 a) confined within mas- sive defensive walls known as main... the published site plan of Dholavira2, the city wall thick- ness is estimated to be 7 m (without salient) and 14 m (with salient) (Figure 2 a). The fortalice style of Harappan architecture is evident at a few other sites, such as Kalibangan, Banawali, Rakhi...

  8. Laparoscopic morgagni hernia repair using single-site umbilical and full-thickness abdominal wall repair: Technical report of two cases

    Directory of Open Access Journals (Sweden)

    Martin L van Niekerk

    2013-01-01

    Full Text Available Single incision laparoscopic surgery is used in many centres for routine cases such as appendisectomy, splenectomy and cholecystectomy. Morgagni hernias are uncommon and account for 1-2% of all congenital diaphragmatic hernia. We report our first laparoscopic repair of two Morgagni hernias, using a single umbilical incision and full-thickness abdominal wall repair with standard straight laparoscopic instruments. Operative time was short and compared favourably with the laparoscopic repair.

  9. Laparoscopic Morgagni hernia repair using single-site umbilical and full-thickness abdominal wall repair: technical report of two cases.

    Science.gov (United States)

    van Niekerk, Martin L

    2013-01-01

    Single incision laparoscopic surgery is used in many centres for routine cases such as appendectomy, splenectomy and cholecystectomy. Morgagni hernias are uncommon and account for 1-2% of all congenital diaphragmatic hernia. We report our first laparoscopic repair of two Morgagni hernias, using a single umbilical incision and full-thickness abdominal wall repair with standard straight laparoscopic instruments. Operative time was short and compared favourably with the laparoscopic repair.

  10. Short-axis epicardial volume change is a measure of cardiac left ventricular short-axis function, which is independent of myocardial wall thickness.

    Science.gov (United States)

    Ugander, Martin; Carlsson, Marcus; Arheden, Håkan

    2010-02-01

    Fractional shortening (FS) by echocardiography is considered to represent the short-axis contribution to the stroke volume (SV), also called short-axis function. However, FS is mathematically coupled to the amount of myocardium, since it rearranges during atrioventricular plane displacement (AVPD). The SV is the sum of the volumes generated by 1) reduction in outer volume of the heart, and 2) inner AVPD. The long-axis contribution to the SV is generated by AVPD, and thus the short-axis contribution is the remaining outer volume change of the heart, which should be unrelated to myocardial wall thickness. We hypothesized that both endocardial and midwall shortening indexed to SV are dependent on myocardial wall thickness, whereas epicardial volume change (EVC) indexed to SV is not. Twelve healthy volunteers (normals), 12 athletes, and 12 patients with dilated cardiomyopathy (ejection fraction EVC was defined as SV minus long-axis function. Endocardial and midwall shortening were measured in a midventricular short-axis slice. Endocardial shortening/SV and midwall shortening/SV both varied in relation to end-diastolic myocardial wall thickness (R(2) = 0.16, P = 0.008 and R(2) = 0.14, P = 0.012, respectively), whereas EVC/SV did not (R(2) = 0.00, P = 0.37). FS is dependent on myocardial wall thickness, whereas EVC is not and therefore represents true short-axis function. This is not surprising considering that FS is mainly caused by rearrangement of myocardium secondary to long-axis function. FS is therefore not synonymous with short-axis function.

  11. Intra-rater and Inter-rater Reliability of Rehabilitative Ultrasound Imaging of Multifidus Muscle Thickness, Cross Section Area and Bladder Wall Displacement in Multiparous Women

    Directory of Open Access Journals (Sweden)

    Zahra Teymuri

    2016-03-01

    Full Text Available Background. Pregnancy related changes can affect the role of multifidus (MF and pelvic floor muscles (PFM in the spinal stability and load transfer mechanism. Rehabilitative ultrasound imaging (RUSI is a powerful tool that provides unavailable information about the myofascial system. Objective. This study aimed to determine intra-rater and inter-rater reliability of ultrasound imaging in the measurement of MF thickness, cross section area (CSA and bladder wall displacement as a reflection of PFM action in multiparous healthy women. Design.A single-group repeated measures reliability study was conducted. Methods. Ten healthy multiparous women (mean age=35.36 SD=7.71 participated in this study. Bladder wall displacement in the transverse plan through trans-abdominal (TA approach, MF muscle thickness at rest and during contralateral arm lift (CAL and MF muscle CSA were obtained by using RUSI. Infraclass correlation coefficient (ICC with 95% confidence interval (CI, standard error of measurement (SEM and minimal detectable change (MDC were calculated for all variables. Results: ICC values with 95% CI showed that bladder wall displacement has high intra-rater (ICC: 0.91-0.99 and high inter-rater reliability (ICC: 0.93-0.96, MF muscle thickness has good to high intra-rater (ICC: ranged from 0.85 to 0.98 and good to high inter-rater reliability (ICC ranged from0.73 to 0.98 and MF muscle CSA has good to high intra-rater (ICC: 0.78-0.86 and fair inter-rater reliability (ICC: 0.54-0.61. SEMs ranged from 0.69 to 3.98 mm and MDCs ranged from 1.92 to 11.03 mm. Limitation.The number of delivery was not equal between subjects. Conclusions. RUSI is a reliable method in measurement of bladder wall displacement, MF muscle thickness and CSA in multiparous women.

  12. Oil pipelines inspection with high wall thickness using MFL tool - Campos Basin experience; Inspecao de oleoduto com paredes espessas com ferramenta MFL - a experiencia da Bacia de Campos

    Energy Technology Data Exchange (ETDEWEB)

    Franzoi, Aldo; Camerini, Claudio; Bueno, Sergio I.O. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Franca, Andre; Miranda, Ivan V. Janvrot; Silva, Jose A.P.; Lima, Vinicius [PipeWay Engenharia, Rio de Janeiro, RJ (Brazil)

    2005-07-01

    Campos Basin deep water pipelines are designed to out stand internal pressure, launching loads and buckling witch demands high wall thickness up to 1 inch. On the other hand, operational conditions require high pumping temperatures to meet requirements of flow assurance. This scenario becomes difficult internal survey specially MFL tools. The present work describes PETROBRAS effort, with PipeWay partnership, looking for alternatives for internal inspection on those pipelines using MFL specially designed, showing details and results from a recent survey. (author)

  13. Experimental study on the buckling and post-buckling behavior of thin-walled cylindrical shells with varying thickness under hydrostatic pressure

    OpenAIRE

    FAKHIM, Y. G.; SHOWKATI, H.; K Abedi

    2009-01-01

    p. 2511-2522 The application of thin-walled cylindrical shells, as the essential structural members, has been known for engineers and functional duty of them is basic necessaries of modern industries. These structures are prone to fail by buckling under external pressure which could be happened during discharging or wind load. Although the buckling capacity of the shells depends principally on two geometric ratios of "length to radius" (L/R) and "radius to thickness" (R/t), but...

  14. Comparison of Monte Carlo simulations with proton experiment for a thick Au absorber

    Energy Technology Data Exchange (ETDEWEB)

    Yevseyeva, Olga; Assis, Joaquim T. de, E-mail: yevseveva@iprj.uerj.b, E-mail: joaquim@iprj.uerj.b [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Inst. Politecnico; Evseev, Ivan; Schelin, Hugo R.; Paschuk, Sergei A.; Milhoretto, Edney; Setti, Joao A.P., E-mail: evseev@utfpr.edu.b, E-mail: schelin@utfpr.edu.b, E-mail: sergei@utfpr.edu.b, E-mail: edneymilhoretto@yahoo.co, E-mail: jsetti@gmail.co [Universidade Tecnologica Federal do Parana, Curitiba, PR (Brazil); Diaz, Katherin S., E-mail: kshtejer@infomed.sld.c [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear, Havana (Cuba); Hormaza, Joel M., E-mail: jmesa@ibb.unesp.b [UNESP, Botucatu, SP (Brazil). Inst. de Biociencias; Lopes, Ricardo T., E-mail: ricardo@lin.ufrj.b [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear

    2009-07-01

    Proton therapy applications deal with relatively thick targets like the human head or the trunk. Therefore, relatively small differences in the total proton stopping power given, for example, by the different models provided by GEANT4, could lead to significant disagreement in the final proton energy spectra when integrated along lengthy proton trajectories. This work presents a comparison of proton energy spectra for 49.1 MeV protons passing through a couple of Au absorbers with different thicknesses obtained by GEANT4.8.2 simulations using ICRU49, Ziegler1985 and Ziegler2000 models. The comparison was made with the experimental data of Tschalaer, with TRIM/SRIM2008 and MCNPX2.4.0 simulations, and the Payne analytical solution for the transport equation in the Fokker-Plank approximation. It is shown that the simulations reproduce the experimental spectra with some detectable contradictions. It should be noted that all the spectra lay at the proton energies significantly above 2 MeV, i.e. in the so-called 'Bethe-Bloch region'. Therefore the observed disagreements in GEANT4 results, simulated with different models, are somewhat unexpected. Further studies for a better understanding and to obtain definitive conclusions are necessary. (author)

  15. Relation of aortic calcification, wall thickness, and distensibility with severity of coronary artery disease: evaluation with coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Seonah; Yong, Hwan Seok; Doo, Kyung Won; Kang, Eun-Young; Woo, Ok Hee; Choi, Eun Jung [Dept. of Radiology, Korea Univ. Guro Hospital, Korea Univ. College of Medicine, Seoul (Korea, Republic of)], e-mail: yhwanseok@naver.com

    2012-10-15

    Background Three known risk factors for aortic atherosclerosis predict the severity of coronary artery disease (CAD): aortic calcification (AC), aortic wall thickness (AWT), and aortic distensibility (AD). Purpose To determine the relationship of AC, AWT, and AD with the severity of CAD. Material and Methods A total of 104 patients who underwent both coronary CT angiography (CCTA) and invasive coronary angiography were enrolled. The severity of CAD was assessed by three methods: the segment involvement score (SIS), the segment stenosis score (SSS), and the modified Gensini score (mG). We quantified AC using the Agatston method on low-dose ungated chest CT (LDCT). We measured AWT at the thickest portion of the descending thoracic aorta on CCTA. AD was calculated as the difference between the maximum and minimum areas of the ascending aorta and the pulse pressure. The relationships between the severity of CAD and the three aortic factors were assessed. Results The AC and AWT of the thoracic aorta were significantly higher in the occlusive CAD (OCAD) group (1984.21 {+-} 2986.10 vs. 733.00 {+-} 1648.71, P = 0.01; 4.13 {+-} 1.48 vs. 3.40 {+-} 1.01, P = 0.22). Patients with OCAD had more than one epicardial coronary artery with >50% luminal stenosis. The AC (r = 0.453 with SIS; r = 0.454 with SSS; r = 0.427 with mG) and the AWT (r = 0.279 with SIS; r = 0.324 with SSS; r = 0.304 with mG) were significantly correlated with all three methods, and the AD was negatively correlated with the SIS (r = - 0.221, P < 0.05, respectively) in the unadjusted model. After adjustment for cardiovascular risk factors, only the correlations between AC and all three methods assessing CAD remained significant. Conclusion There are significant relationships between AC, AWT and AD and severity of CAD. In particular, AC measured on LDCT is the most consistent predictor of severity of CAD.

  16. Evaluación del espesor parietal relativo en la especie canina Evaluation of relative wall thickness in dogs

    Directory of Open Access Journals (Sweden)

    C. Lightowler

    2005-12-01

    Full Text Available Tanto los fenómenos patológicos como el ejercicio y entrenamiento promueven en el corazón fenómenos de adaptación, que varían según el mecanismo que los promueve. Uno de los mecanismos que se encuentra siempre en la adaptación cardiaca es la hipertrofia del miocardio. El grado de hipertrofia puede evaluarse midiendo la masa miocárdica ventricular izquierda. Sin embargo este parámetro evalúa la cantidad de hipertrofia, pero no la manera en que ésta se distribuye. Dicha distribución puede calcularse por medio del índice ecocardiográfico conocido como espesor parietal relativo (EPR. En este trabajo, los autores presentan la técnica ecocardiográfica para la evaluación del EPR en el perro y su valor normal promedio. Los resultados obtenidos fueron los siguientes: Media: 0,482; Desviación estándar: 0,098; Coeficiente de variación: 18,37%; Valor mínimo: 0,355; Primer cuartil: 0,407; Mediana: 0,459; Tercer cuartil: 0,528; Valor máximo: 0,728. Asimismo, se verificó la inexistencia de regresión lineal entre el EPR y el peso corporal.As much as the pathological phenomena the exercise and training promote in the heart adaptation phenomena, which vary according to the mechanism that promotes them. One of the mechanisms that is always present in cardiac adaptation is hypertrophy of myocardium. The degree of hypertrophy can be evaluated measuring the left ventricular myocardial mass. Nevertheless this parameter measures the amount of hypertrophy, but not how it is distributed; this can be evaluated by means of relative wall thickness (RWT index. In the present study the authors describe the echocardiography technique for the evaluation of the RWT in the dog and present its normal mean value. The results obtained were the following: Mean: 0,482; Standard deviation: 0,098; Coefficient of variation: 18,37%; Minimum value: 0,355; First quartile: 0,407; Median: 0,459; Third quartile: 0,528; Maximum value: 0,728. Also was verified the

  17. Association of aortic wall thickness on contrast-enhanced chest CT with major cerebro-cardiac events.

    Science.gov (United States)

    Tresoldi, Silvia; Di Leo, Giovanni; Zoffoli, Elena; Munari, Alice; Primolevo, Alessandra; Cornalba, Gianpaolo; Sardanelli, Francesco

    2014-11-01

    There is a significant association between aortic atherosclerosis and previous major cardiovascular events. Particularly, thoracic aortic atherosclerosis is closely related to the degree of coronary and carotid artery disease. Thus, there is a rationale for screening the thoracic aorta in patients who undergo a chest computed tomography (CT) for any clinical question, in order to detect patients at increased risk of cerebro-cardiovascular (CCV) events. To estimate the association between either thoracic aortic wall thickness (AWT) or aortic total calcium score (ATCS) and CCV events. One hundred and forty-eight non-cardiac patients (78 men; 67 ± 12 years) underwent chest contrast-enhanced multidetector CT (MDCT). The AWT was measured at the level of the left atrium (AWTref) and at the maximum AWT (AWTmax). Correlation with clinical CCV patients' history was estimated. The value of AWTmax and of a semi-quantitative ATCS as a marker for CCV events was assessed using receiver-operating characteristic curve (ROC) analysis and multivariate regression analysis. Out of 148 patients, 59% reported sedentary lifestyle, 44% hypertension, 32% smoking, 23% hypercholesterolemia, 13% family history of cardiac disease, 12% diabetes, and 10% BMI ≥ 30 kg/m(2); 9% reported myocardial infarction, 8% aortic aneurism, 8% myocardial revascularization, and 2% ischemic stroke. Twenty-six percent of patients had a medium-to-high ATCS. Both AWTmax and AWTref correlated with hypertension and age (P < 0.002). At the ROC analysis, a 4.8 mm threshold was associated to a 90% specificity and an odds ratio of 6.3 (AUC = 0.735). Assuming as threshold the AWTmax median value (4.3 mm) of patients who suffered from at least one CCV event in their history, a negative predictive value of 90%, a RR of 3.6 and an OR of 6.3 were found. At the multivariate regression analysis, AWTmax was the only independent variable associated to the frequency of CCV events. Patients with increased thoracic

  18. Energy, cost, and CO 2 emission comparison between radiant wall panel systems and radiator systems

    CERN Document Server

    Bojić, Milorad; Miletić, Marko; Malešević, Jovan; Boyer, Harry

    2012-01-01

    The main goal of this paper is to evaluate the possibility of application or replacement of radiators with low-temperature radiant panels. This paper shows the comparison results of operations of 4 space heating systems: the low-temperature radiant panel system without any additional thermal insulation of external walls (PH-WOI), the low-temperature radiant panel system with additional thermal insulation of external walls (PH-WI), the radiator system without any additional thermal insulation of external walls (the classical heating system) (RH-WOI), and the radiator system with additional thermal insulation of external walls (RH-WI). The operation of each system is simulated by software EnergyPlus. The investigation shows that the PH-WI gives the best results. The RH-WOI has the largest energy consumption, and the largest pollutant emission. However, the PH-WI requires the highest investment.

  19. Assessing the thickness of the vaginal wall and vaginal mucosa in pre-menopausal versus post-menopausal women by transabdominal ultrasound: A feasibility study.

    Science.gov (United States)

    Balica, Adrian; Wald-Spielman, Daniella; Schertz, Katherine; Egan, Susan; Bachmann, Gloria

    2017-08-01

    As life expectancy increases, the number of women reporting adverse genito-urinary symptoms (genitourinary syndrome of menopause; GSM) from menopause, including vaginal dryness and sexual pain, also will increase. Current objective measurements of vaginal atrophy such as maturation index require vaginal swabs and are invasive; at present, no minimally invasive measurements exist. The purpose of this study was to assess whether total vaginal wall thickness (TVT) and total vaginal mucosa thickness (TMT) as measured by transabdominal ultrasound could qualify as additional objective markers of vaginal wall thinning which could be related to menopausal status. Women presenting for pelvic ultrasound had a transabdominal ultrasound scan performed to measure TVT and TMT at the level of the bladder trigone. In addition, a transvaginal endometrial lining thickness was measured. The ultrasound measurement data from 76 participants showed that there was a significant difference in the mean value for TVT and endometrial lining between pre- and post-menopausal women. The same difference in mean was not observed for TMT. TVT may be a reliable measure of vaginal thinning, which worsens with estrogen decline. These preliminary data also suggest that TMT does not have the same correlation as the TVT measurement. A larger sample is needed to further assess the usefulness and sensitivity of these measures and whether there is clinical and/or research usefulness in obtaining vaginal wall measurements by transabdominal ultrasound. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. A Computed Tomographic Study on the Size and Bone Wall Thickness of the Maxillary Sinus in Normal, Preoperative and Postoperative Maxillary Sinusitis Patients

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sun Young; Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology and Institute of Oral Bio Science, School of Dentistry, Chpnbuk National University, Chonju (Korea, Republic of); Lee, Sang Rae [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Kyunghee University, Seoul (Korea, Republic of)

    2000-06-15

    To compare the size and bone wall thickness of the maxillary sinus in normal, preoperative and postoperative maxillary sinusitis patients. The author analyzed CT images of both left and right maxillary sinuses in 357 patients who visited Chonbuk National University Hospital between January 1997 and December 1998. The size and bone wall thickness of the maxillary sinus of normal, inflammatory and post-Caldwell-Luc groups were compared. The significant differences of transverse, maximum medio-lateral, maximum supero-inferior dimensions and medio-lateral dimension at nasal floor level between normal and post-Caldwell-Luc groups were found (P<0.05). And the significant differences of antero-posterior dimensions between inflammatory and post-Caldwell-Luc group were found (P<0.05). But, no significant differences of vertical height dimensions between groups was found (P>0.05). The significant differences of postero-lateral, infero-lateral and medial wall thickness between normal and post-Caldwell-Luc groups were found (P<0.05). The results of this study will aid in the diagnosis and treatment of maxillary sinus diseases and post operative treatment planning.

  1. Analytical solution for spatially axisymmetric problem of thick-walled cylinder subjected to different linearly varying pressures along the axis and uniform pressures at two ends

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To our best knowledge,in the open literature,there is no analytical solution of thick-walled cylinder subjected to uniform pressures at two ends and different inner-and outer-surface pressures that are constant circumferentially but vary linearly at different rates along the axis.We now present such a solution.After repeated trials,we have finally succeeded in finding a necessary new displacement function.Based on A.E.H.Love method,the stress,displacement and volume strain formulas are derived by using the new displacement function.The present results include the Lamé’s formulas as special cases.Furthermore,the results obtained here can be applied to not only the thick-walled cylinders subjected to uniform pressures on the inner and outer surface of the thick-walled cylinder,respectively,but also the cylinders subjected to uniform pressures at two ends and dif- ferent inner-and outer-surface pressures that are constant circumferentially but vary linearly at different rates along the axis,respectively.Finally we give a numerical example to compare our exact method with the approximate method.

  2. Model experimental research on deformation and subsidence characteristics of ground and wall rock due to mining under thick overlying terrane

    Energy Technology Data Exchange (ETDEWEB)

    Weizhong Ren; Chengmai Guo; Ziqiang Peng; Yonggang Wang [Chinese Academy of Sciences, Wuhan (China). Institute of Rock and Soil Mechanics

    2010-06-15

    Based on the prototype of a mine, a physical simulation test is conducted. The characteristics of the deformation and failure of the ground surface and the wall rock around a goaf, as well as the creep behavior of the wall rock deformation and the failure mechanism, are analyzed. The simulation test has greatly improved our understanding on the wall rock's deformation and failure characteristics. For the first time, digital close-range photogrammetry was used to measure the displacements in a sectional model test. The measurements by this technique agreed very well with those obtained by other methods, such as using dial gauges.

  3. wall

    Directory of Open Access Journals (Sweden)

    Irshad Kashif

    2016-01-01

    Full Text Available Maintaining indoor climatic conditions of buildings compatible with the occupant comfort by consuming minimum energy, especially in a tropical climate becomes a challenging problem for researchers. This paper aims to investigate this problem by evaluating the effect of different kind of Photovoltaic Trombe wall system (PV-TW on thermal comfort, energy consumption and CO2 emission. A detailed simulation model of a single room building integrated with PV-TW was modelled using TRNSYS software. Results show that 14-35% PMV index and 26-38% PPD index reduces as system shifted from SPV-TW to DGPV-TW as compared to normal buildings. Thermal comfort indexes (PMV and PPD lie in the recommended range of ASHARE for both DPV-TW and DGPV-TW except for the few months when RH%, solar radiation intensity and ambient temperature were high. Moreover PVTW system significantly reduces energy consumption and CO2 emission of the building and also 2-4.8 °C of temperature differences between indoor and outdoor climate of building was examined.

  4. Computed tomography scan measurement of abdominal wall thickness for application of near-infrared spectroscopy probes to monitor regional oxygen saturation index of gastrointestinal and renal circulations in children.

    Science.gov (United States)

    Balaguru, Duraisamy; Bhalala, Utpal; Haghighi, Mohammad; Norton, Karen

    2011-05-01

    To measure abdominal wall thickness to determine the depth at which the renal vascular bed and mesenteric vascular bed are located, and to determine the appropriate site for placement of near-infrared spectroscopy probes for accurate monitoring regional oxygen saturation index in children. Abdominal computerized tomography scans in children were used to measure the abdominal wall thickness and to ascertain the location of kidneys. Tertiary care children's hospital. Children 0-18 yrs of age; n = 38. None. The main mass of the kidneys is located between vertebral levels T12 and L2 on both sides. The left kidney is located about a half-vertebral length higher than the right kidney. Posterior abdominal wall thickness ranged from 6.6 to 115.8 mm (median, 22.1 mm). Posterolateral abdominal wall thickness ranged from 6.7 to 114.5 mm (median, 19.6 mm). Anterior abdominal wall thickness in the supraumbilical level ranged from 3.5 to 62.9 mm (median, 16.0 mm). All abdominal wall thicknesses correlated better with weight of the subjects than their age. Abdominal wall thickness potentially exceeds the sampling depth of currently used near-infrared spectroscopy probes above a certain body size. Application of current near-infrared spectroscopy probes and design of future probes should consider patient size variations in the pediatric population.

  5. 利用相控阵技术对于厚壁钢管的探伤方法研究%Research of thick-walled steel pipe testing method using phased array technology

    Institute of Scientific and Technical Information of China (English)

    陈树

    2016-01-01

    For the non-destructive testing of thick-walled steel pipe, in general use ray testing or ultrasonic testing. But ray testing or A ultrasonic testing spent more time and low efifciency. Advanced ultrasonic phased array testing technology can improve efifciency. The feasibility and reliability of the thick-walled steel pipe testing was veriifed by drawing a DAC curve of test block comparison method.%对于厚壁钢管的无损探伤,一般采取射线探伤或超声波探伤。但射线探伤和A超探伤所耗费的时间比较长,效率不高。我们可以通过研究超声波中较为先进的相控阵探伤技术来提高效率。对此我们通过试块对比法绘制DAC曲线来验证相控阵技术在钢制厚壁圆管的探伤中的可行性和可靠性。

  6. Effects of wall condition on flow distributions in arterial modeling: comparison of rigid, dynamic, and compliant walls

    Energy Technology Data Exchange (ETDEWEB)

    He, Fan [Beijing University of Civil Engineering and Architecture, Beijing (China); Hua, Lu; Gao, Li jian [Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China)

    2016-03-15

    Blood flow distributions were evaluated using various computational strategies. Three commonly used wall conditions in arterial modeling were employed, namely rigid, dynamic and compliant walls. The results show that the velocity distributions are similar under rigid and dynamic walls, developing into the Poiseuille flow, but they are blunt under compliant walls. The peak pressure under rigid walls is highest, but the model of dynamic walls has a good approximation of pressure against the model of compliant walls. The results indicate that a model of compliant walls appears to be a computationally and reasonably accurate approximation of blood velocity distributions compared with the analysis under rigid or dynamic walls. Introducing fluid-structure interaction into arterial modeling is necessary to ensure reliable results and information. However, a model of dynamic walls seems to be a computationally inexpensive yet reasonably accurate approximation for pressure.

  7. Hypertensive heart disease versus hypertrophic cardiomyopathy: multi-parametric cardiovascular magnetic resonance discriminators when end-diastolic wall thickness ≥ 15 mm

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Jonathan C.L. [University Hospitals Bristol NHS Foundation Trust, NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute (United Kingdom); University of Bristol, School of Physiology, Pharmacology and Neuroscience, Faculty of Biomedical Sciences (United Kingdom); Rohan, Stephen [University of Bristol, Medical School, Faculty of Medicine and Dentistry (United Kingdom); Ghosh Dastidar, Amardeep; Harries, Iwan; Lawton, Christopher B. [University Hospitals Bristol NHS Foundation Trust, NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute (United Kingdom); Ratcliffe, Laura E.; Burchell, Amy E.; Nightingale, Angus K. [University Hospitals Bristol NHS Foundation Trust, CardioNomics Research Group, Clinical Research and Imaging Centre, Bristol Heart Institute (United Kingdom); Hart, Emma C.; Paton, Julian F.R. [University of Bristol, School of Physiology, Pharmacology and Neuroscience, Faculty of Biomedical Sciences (United Kingdom); University Hospitals Bristol NHS Foundation Trust, CardioNomics Research Group, Clinical Research and Imaging Centre, Bristol Heart Institute (United Kingdom); Hamilton, Mark C.K. [University Hospitals Bristol NHS Foundation Trust, Department of Radiology, Bristol Royal Infirmary (United Kingdom); Manghat, Nathan E. [University Hospitals Bristol NHS Foundation Trust, NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute (United Kingdom); University Hospitals Bristol NHS Foundation Trust, Department of Radiology, Bristol Royal Infirmary (United Kingdom)

    2017-03-15

    European guidelines state left ventricular (LV) end-diastolic wall thickness (EDWT) ≥15 mm suggests hypertrophic cardiomyopathy (HCM), but distinguishing from hypertensive heart disease (HHD) is challenging. We identify cardiovascular magnetic resonance (CMR) predictors of HHD over HCM when EDWT ≥15 mm. 2481 consecutive clinical CMRs between 2014 and 2015 were reviewed. 464 segments from 29 HCM subjects with EDWT ≥15 mm but without other cardiac abnormality, hypertension or renal impairment were analyzed. 432 segments from 27 HHD subjects with EDWT ≥15 mm but without concomitant cardiac pathology were analyzed. Magnitude and location of maximal EDWT, presence of late gadolinium enhancement (LGE), LV asymmetry (>1.5-fold opposing segment) and systolic anterior motion of the mitral valve (SAM) were measured. Multivariate logistic regression was performed. Significance was defined as p<0.05. HHD and HCM cohorts were age-/gender-matched. HHD had significantly increased indexed LV mass (110±27 g/m{sup 2} vs. 91±31 g/m{sup 2}, p=0.016) but no difference in site or magnitude of maximal EDWT. Mid-wall LGE was significantly more prevalent in HCM. Elevated indexed LVM, mid-wall LGE and absence of SAM were significant multivariate predictors of HHD, but LV asymmetry was not. Increased indexed LV mass, absence of mid-wall LGE and absence of SAM are better CMR discriminators of HHD from HCM than EDWT ≥15 mm. circle Hypertrophic cardiomyopathy (HCM) is often diagnosed with end-diastolic wall thickness ≥15 mm. (orig.)

  8. Comparison of Residual Stress Distributions of Similar and Dissimilar Thick Butt-Weld Plates

    Science.gov (United States)

    Suzuki, Hiroshi; Katsuyama, Jinya; Morii, Yukio

    Residual stress distributions of 35 mm thick dissimilar metal butt-weld between A533B ferritic steel and Type 304 austenitic stainless steel (304SS) with Ni alloy welds and similar metal butt-weld of 304SS were measured using neutron diffraction. Effects of differences in thermal expansion coefficients (CTEs) and material strengths on the weld residual stress distributions were discussed by comparison of the residual stress distributions between the similar and dissimilar metal butt-welds. Residual stresses in the similar metal butt-weld exhibited typical distributions found in a thick butt-weld and they were distributed symmetrically on either side of the weld line. Meanwhile, asymmetric residual stress distributions were observed near the root of the dissimilar metal butt-weld, which was caused by differences in CTEs and yield strengths among both parent materials and weld metals. Transverse residual stress distribution of the dissimilar metal butt-weld was similar trend to that of the similar metal butt-weld, since effect of difference in CTEs were negligible, while magnitude of the transverse residual stress near the root depended on the yield strengths of each metal. In contrast, the normal and longitudinal residual stresses in the dissimilar metal butt-weld distributed asymmetrically on either side of weld line due to influence of differences in CTEs.

  9. Percent wall thickness evaluated by Gd-DTPA enhanced cine MRI as an indicator of local parietal movement in hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Masaharu [Tokyo Medical Coll. (Japan)

    1998-11-01

    Hypertrophic cardiomyopathy (HCM) is a cardiac disease, the basic pathology of which consists of a decrease in left ventricular dilation compliance due to uneven hypertrophy of the left ventricular wall. Magnetic resonance imaging (MRI) is useful in monitoring uneven parietal hypertrophy and kinetics in HCM patients. The present study was undertaken in 47 HCM patients who showed asymmetrical septal hypertrophy to determine if percent thickness can be an indicator of left ventricular local movement using cine MRI. Longest and shortest axis images were acquired by the ECG synchronization method using a 1.5 T MR imager. Cardiac function was analyzed based on longest axis cine images, and telediastolic and telesystolic parietal thickness were measured based on shorter axis cine images at the papillary muscle level. Parietal movement index and percent thickness were used as indicators of local parietal movement. The correlation between these indicators and parietal thickness was evaluated. The percent thickness changed at an earlier stage of hypertrophy than the parietal movement index, thus it is thought to be useful in detecting left ventricular parietal movement disorders at an early stage of HCM. (author)

  10. Interfacial heat transfer in squeeze casting of magnesium alloy AM60 with variation of applied pressures and casting wall-thicknesses

    Science.gov (United States)

    Zhang, Xuezhi; Fang, Li; Sun, Zhizhong; Hu, Henry; Nie, Xueyuan; Tjong, Jimi

    2016-10-01

    The heat transfer coefficient at the casting-die interface is the most important factor on the solidification process. With the 75-ton hydraulic press machine and P20 steel die mold, 5-step castings of magnesium alloy AM60 with different wall-thicknesses (3, 5, 8, 12, 20 mm) were poured under various hydraulic pressures (30, 60, and 90 MPa) using an indirect squeeze casting process. Thermal histories throughout the die wall and the casting surface have been recorded by fine type-K thermocouples. The in-cavity local pressures measured by pressure transducers were explored at the casting-die interfaces of 5 steps. The casting-die interfacial heat transfer coefficients (IHTC) initially reached a maximum peak value followed by a gradually decline to the lower level. Similar characteristics of IHTC peak values can be observed at the applied pressures of 30, 60 and 90 MPa. With the applied pressure of 90 MPa, the peak IHTC values from steps 1 to 5 varied from 5623 to 10,649 W/m2 K. As the applied hydraulic pressure increased, the IHTC peak value of each step was increased accordingly. The wall thickness also affected IHTC peak values significantly. The peak IHTC value and heat flux increased as the step became thicker. The empirical equations relating the IHTCs to the local pressures and the solidification temperature at the casting surface were developed based on the multivariate linear and polynomial regression.

  11. Data density curves of B-mode ultrasound arterial wall thickness measurements in unaffected control and at-risk populations

    NARCIS (Netherlands)

    de Groot, E; Hovingh, GK; Zwinderman, AH; Wiegman, A; Smit, AJ; Kastelein, JJP

    2005-01-01

    Aim. Atherosclerosis is a slow disease process of arterial walls with onset decades prior to its clinical manifestations. Lifelong follow-up data may help to identify and understand the pathophysiology of this process. These longitudinal data are scarce. Using a standardized imaging and image analys

  12. Determination of the chest wall thicknesses and needle thoracostomy success rates at second and fifth intercostal spaces: a cadaver-based study.

    Science.gov (United States)

    Ozen, Can; Akoglu, Haldun; Ozdemirel, Rifat Ozgur; Omeroglu, Elif; Ozpolat, Cigdem Ulubay; Onur, Ozge; Buyuk, Yalcin; Denizbasi, Arzu

    2016-12-01

    The purposes of this study were to measure the chest wall thicknesses (CWTs) at second intercostal space (ICS) mid-clavicular line (MCL) and fifth ICS MAL directly, and compare the actual success rates of needle thoracostomies (NTs) by inserting a 5-cm-long syringe needle. Predictive values of weight, body mass index (BMI) and CWT were also analyzed. This study included 199 measurements of 50 adult fresh cadavers from both hemithoraces. Five-centimeter-long syringe needles were inserted and secured. Penetration into the pleural cavity was assessed, and CWTs at 4 locations were measured. Achieved power of this study for the primary aim of CWT comparison from 2(nd) and 5(th) ICSs was .94. Overall mean CWTs at 2(nd) ICS MCL and 5(th) ICS MAL were measured as 2.46 ± 0.78 and 2.89 ± 1.09, respectively, and 5(th) ICS MAL was found to be statistically thicker (P = .002). The success rate of NT at 2(nd) ICS MCL was 87% (95% CI, 80-94), and that at 5(th) ICS MAL was 78% (95% CI, 70-86; P = .3570). Only 6 (17.1%) of 35 failed NTs had a CWT greater than 5-cm. Needle thoracostomy has failed in 29 (14.9%) of 194 locations, despite a CWT less than 5-cm. Below a weight of 72 kg, BMI of 23 kg/m(2), or CWT of 2.4 cm, all NTs were successful. In this report, we present the largest cadaver-based cohort to date to the best of our knowledge, and we observed a statistically nonsignificant 9% more NT success rate at 2(nd) ICS at a power of 88% and statistically significant more success rate in males at 5(th) ICS was (47.7%). We also observed thinner CWTs and higher success rates than previous imaging-based studies. A BMI of 23 kg/m(2) or less and weight of 72 kg or less seem to accurately rule-out NT failure in cadavers, and they seem to be better predictors at the bedside. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Development of a Versatile Laser-Ultrasonic System and Application to the Online Measurement for Process Control of Wall Thickness and Eccentricity of Seamless Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Robert V. Kolarik II

    2002-10-23

    A system for the online, non-contact measurement of wall thickness in steel seamless mechanical tubing has been developed and demonstrated at a tubing production line at the Timken Company in Canton, Ohio. The system utilizes laser-generation of ultrasound and laser-detection of time of flight with interferometry, laser-doppler velocimetry and pyrometry, all with fiber coupling. Accuracy (<1% error) and precision (1.5%) are at targeted levels. Cost and energy savings have exceeded estimates. The system has shown good reliability in measuring over 200,000 tubes in its first six months of deployment.

  14. Effects of cross-linking, capsule wall thickness, and compound hydrophobicity on aroma release from complex coacervate microcapsules.

    Science.gov (United States)

    Leclercq, Segolene; Milo, Christian; Reineccius, Gary A

    2009-02-25

    Microcapsules were produced by complex coacervation with a gelatin-gum acacia wall and medium-chain-triglyceride core. Dry capsules were partially rehydrated and then loaded with model aroma compounds covering a range of volatility, hydrophobicity, and molecular structure. An experimental design was prepared to evaluate the effects of cross-linking, wall/core ratio, and volatile load level on aroma release from capsules in a hot, aqueous environment. The real-time release on rehydration was measured by monitoring the headspace of a vessel containing the capsules to proton transfer reaction mass spectrometry (PTR-MS). Data collected showed no effects of cross-linking or wall/core ratio on volatile release in hot water for any of the volatiles studied. When comparing real-time release of the prepared coacervates to a spray-dried equivalent, there was no difference in the release from hot water but the release was slower when coacervates were added to ambient-temperature water. We found volatile release to be primarily determined by compound partition coefficients (oil/water and water/air) and temperature.

  15. 机械自紧厚壁圆管强度的实验研究%Experimental Research on Thick-walled Cylinder Strength with Swage Autofrettage

    Institute of Scientific and Technical Information of China (English)

    袁人枢; 连源

    2012-01-01

    设计了机械自紧实验所用的厚壁圆筒试件,搭建了机械自紧实验装置,对不同径比、不同过盈量的厚壁圆筒进行机械自紧实验,测试自紧后试件的再屈服强度.考虑稳定化处理和机械加工的工艺过程,结合实验结果提出机械自紧厚壁圆管强度计算经验公式,计算得到的强度数值与实验测量值的误差在±10%以内.%The thick-walled cylinder specimen was designed and the swage autofrettage experimental devicefor the thick-walled cylinder which boasting of different diameter ratios and magnitudes of interference was built to test re-yield strength of the specimen; and considering the post-autofrettage thermal treatment and machining and experimental results, the empirical formula for the strength was obtained and the results show that the experimental error between calculated result and experimental result is less then ?10% .

  16. New triblock copolymer templates, PEO-PB-PEO, for the synthesis of titania films with controlled mesopore size, wall thickness, and bimodal porosity.

    Science.gov (United States)

    Ortel, Erik; Fischer, Anna; Chuenchom, Laemthong; Polte, Jörg; Emmerling, Franziska; Smarsly, Bernd; Kraehnert, Ralph

    2012-01-23

    The synthesis and properties of a series of new structure-directing triblock copolymers with PEO-PB-PEO structure (PEO = poly(ethylene oxide) and PB = polybutadiene) and their application as superior pore-templates for the preparation of mesoporous titania coatings are reported. Starting from either TiCl4 or from preformed TiO2 nanocrystalline building blocks, mesoporous crystalline titanium oxide films with a significant degree of mesoscopic ordered pores are derived, and the pore size can be controlled by the molecular mass of the template polymer. Moreover, the triblock copolymers form stable micelles already at very low concentration, i.e., prior to solvent evaporation during the evaporation-induced self-assembly process (EISA). Consequently, the thickness of pore walls can be controlled independently of pore size by changing the polymer-to-precursor ratio. Thus, unprecedented control of wall thickness in the structure of mesoporous oxide coatings is achieved. In addition, the micelle formation of the new template polymers is sufficiently distinct from that of typical commercial PPO-PEO-PPO polymers (Pluronics; PPO = poly(propylene oxide)), so that a combination of both polymers facilitates bimodal porosity via dual micelle templating.

  17. Comparison of the thick smear and Kato-Katz techniques for diagnosis of intestinal helminth infections

    Directory of Open Access Journals (Sweden)

    Santos Fred Luciano Neves

    2005-01-01

    Full Text Available This study compared the efficiency of Kato-Katz thick smear and thick smear techniques for the diagnosis of intestinal helminths. The sensitivity of the thick smear technique was higher than that of the Kato-Katz method for the diagnosis of all helminths except Schistosoma mansoni.

  18. Optimization of wall thickness and lay-up for the shell-like composite structure loaded by non-uniform pressure field

    Science.gov (United States)

    Shevtsov, S.; Zhilyaev, I.; Oganesyan, P.; Axenov, V.

    2017-01-01

    The glass/carbon fiber composites are widely used in the design of various aircraft and rotorcraft components such as fairings and cowlings, which have predominantly a shell-like geometry and are made of quasi-isotropic laminates. The main requirements to such the composite parts are the specified mechanical stiffness to withstand the non-uniform air pressure at the different flight conditions and reduce a level of noise caused by the airflow-induced vibrations at the constrained weight of the part. The main objective of present study is the optimization of wall thickness and lay-up of composite shell-like cowling. The present approach assumes conversion of the CAD model of the cowling surface to finite element (FE) representation, then its wind tunnel testing simulation at the different orientation of airflow to find the most stressed mode of flight. Numerical solutions of the Reynolds averaged Navier-Stokes (RANS) equations supplemented by k-w turbulence model provide the spatial distributions of air pressure applied to the shell surface. At the formulation of optimization problem the global strain energy calculated within the optimized shell was assumed as the objective. A wall thickness of the shell had to change over its surface to minimize the objective at the constrained weight. We used a parameterization of the problem that assumes an initiation of auxiliary sphere with varied radius and coordinates of the center, which were the design variables. Curve that formed by the intersection of the shell with sphere defined boundary of area, which should be reinforced by local thickening the shell wall. To eliminate a local stress concentration this increment was defined as the smooth function defined on the shell surface. As a result of structural optimization we obtained the thickness of shell's wall distribution, which then was used to design the draping and lay-up of composite prepreg layers. The global strain energy in the optimized cowling was reduced in2

  19. The influence of wall thickness on the microstructure of bronze BA1055 with the additions of Si, Cr, Mo and/or W

    Directory of Open Access Journals (Sweden)

    B.P. Pisarek

    2008-12-01

    Full Text Available Aluminium bronzes belong to the high-grade constructional materials applied on the put under strongly load pieces of machines, about good sliding, resistant properties on corrosion both in the cast state how and after the thermal processing. It moves to them Cr and Si in the aim of the improvement of their usable proprieties. Additions Mo and/or W were not applied so far in the larger concentration, these elements were introduced to the melts of the copper as the components of modifiers. It was worked out therefore the new kind of bronzes casting including these elements. Make additions to the Cu-Al-Fe-Ni bronze of Si, Cr, Mo and/or W in the rise of these properties makes possible. The investigations of the influence of the wall thickness of the cast on size of crystallites were conducted: the primary phase β and intermetallic phase κ and the width separates of the secondary phase α precipitate at phase boundary. It results from conducted investigations, that in the aluminium bronze BA1055 after simultaneous makes additions Si, Cr, Mo and in the primary phase β it undergoes considerable reducing size. The addition W reduce size of the grain phase β in the thin walls of the cast 3-6 mm, and addition Cr in the range of the thickness of the wall of the cast 3-6 mm it favors to reducing size the phase β, in walls 12-25 mm the growth causes it. The addition Mo does not influence the change of the size of the grain of the β phase significantly. The make addition singly or simultaneously of the Cr, Mo and W to the bronze CuAl10Fe5Ni5Si it influences the decrease of the quantity separates of the phase α on the interface boundary and of width it separates independently from the thickness of the wall of the cast. The simultaneous make addition of the Si, Cr, Mo and W it enlarges the surface of the phase κFe, κMo. The make addition to the bronze CuAl10Fe5Ni5Si of the Cr, Mo or W the quantity of crystallizing hard phase κ enlarges and the

  20. Increased infarct wall thickness by a bio-inert material is insufficient to prevent negative left ventricular remodeling after myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Aboli A Rane

    Full Text Available BACKGROUND: Several injectable materials have been shown to preserve or improve cardiac function as well as prevent or slow left ventricular (LV remodeling post-myocardial infarction (MI. However, it is unclear as to whether it is the structural support or the bioactivity of these polymers that lead to beneficial effects. Herein, we examine how passive structural enhancement of the LV wall by an increase in wall thickness affects cardiac function post-MI using a bio-inert, non-degradable synthetic polymer in an effort to better understand the mechanisms by which injectable materials affect LV remodeling. METHODS AND RESULTS: Poly(ethylene glycol (PEG gels of storage modulus G' = 0.5±0.1 kPa were injected and polymerized in situ one week after total occlusion of the left coronary artery in female Sprague Dawley rats. The animals were imaged using magnetic resonance imaging (MRI at 7±1 day(s post-MI as a baseline and again post-injection 49±4 days after MI. Infarct wall thickness was statistically increased in PEG gel injected vs. control animals (p<0.01. However, animals in the polymer and control groups showed decreases in cardiac function in terms of end diastolic volume, end systolic volume and ejection fraction compared to baseline (p<0.01. The cellular response to injection was also similar in both groups. CONCLUSION: The results of this study demonstrate that passive structural reinforcement alone was insufficient to prevent post-MI remodeling, suggesting that bioactivity and/or cell infiltration due to degradation of injectable materials are likely playing a key role in the preservation of cardiac function, thus providing a deeper understanding of the influencing properties of biomaterials necessary to prevent post-MI negative remodeling.

  1. Direct measurement of wall slip and slip layer thickness of non-Brownian hard-sphere suspensions in rectangular channel flows

    Science.gov (United States)

    Jesinghausen, Steffen; Weiffen, Rene; Schmid, Hans-Joachim

    2016-09-01

    Wall slip is a long-known phenomenon in the field of rheology. Nevertheless, the origin and the evolution are not completely clear yet. Regarding suspensions, the effect becomes even more complicated, because different mechanisms like pure slip or slip due to particle migration have to be taken into account. Furthermore, suspensions themselves show many flow anomalies and the isolation of slip is complicated. In order to develop working physical models, further insight is necessary. In this work, we measured experimentally the wall slip velocities of different highly filled suspensions in a rectangular slit die directly with respect to the particle concentration and the particle size. The slip velocities were obtained using a particle image velocimetry (PIV) system. The suspensions consisting of a castor oil-cinnamon oil blend and PMMA particles were matched in terms of refractive indexes to appear transparent. Hereby, possible optical path lengths larger than 15 mm were achieved. The slip velocities were found to be in a quadratic relation to the wall shear stress. Furthermore, the overall flow rate as well as the particle concentration has a direct influence on the slip. Concerning the shear stress, there seem to be two regions of slip with different physical characteristics. Furthermore, we estimated the slip layer thickness directly from the velocity profiles and propose a new interpretation. The PIV technique is used to investigate the viscosity and implicit the concentration profile in the slit die. It is shown that the particle migration process is quite fast.

  2. Comparison of two porcine-derived materials for repairing abdominal wall defects in rats.

    Directory of Open Access Journals (Sweden)

    Zhengni Liu

    Full Text Available OBJECTIVE: The purpose of this study was to compare the mechanical properties, host responses and incorporation of porcine small intestine submucosa (PSIS and porcine acellular dermal matrix (PADM in a rat model of abdominal wall defect repair. MATERIALS AND METHODS: Prior to implantation, PSIS and PADM were prepared and evaluated in terms of structure and mechanical properties. Full-thickness abdominal wall defects were created in 50 Sprague-Dawley rats, and were repaired using either PSIS or PADM. Rats were sacrificed 1, 2, 4, 8 and 12 weeks post-repair and examined for herniation, infection, adhesions, contraction, and changes in the thickness and strength of the tissues incorporated at the defect sites. Histopathology and immunohistochemistry were performed to analyze inflammatory responses, collagen deposition and vascularization. RESULTS: PADM showed more dense collagen deposition and stronger mechanical properties than PSIS prior to implantation (P<0.01. However, the mechanical properties observed after integration with the surrounding native tissues was similar for PADM and PSIS. Both PADM and PSIS showed significant contraction by week 12. However, PADM tissue induced less adhesion and increased in thickness more slowly, and showed less infiltration by foreign giant cells, polymorphonuclear cells, and mononuclear cells. Improved remodeling of host tissue was observed after PSIS implantation, which was apparent from the orientation of bands of fibrous connective tissue, intermixed with newly formed blood vessels by Week 12. CONCLUSION: PSIS showed weaker mechanical properties prior to implantation. However, after implantation PSIS induced more pronounced host responses and showed better incorporation into host tissues than PADM.

  3. Individuals, grasses, and forests of single- and multi-walled carbon nanotubes grown by supported Co catalysts of different nominal thicknesses

    Science.gov (United States)

    Kakehi, Kazunori; Noda, Suguru; Maruyama, Shigeo; Yamaguchi, Yukio

    2008-08-01

    The relationships among the nominal thickness of Co catalyst, the structure of the catalyst particles, and the structure of carbon nanotubes (CNTs) growing from the catalyst during chemical vapor deposition were investigated. Various morphologies of CNTs such as individuals, random networks parallel to the surface of the substrate ('grasses'), and vertically aligned forests of single- and multi-walled carbon nanotubes were grown by only varying the nominal thickness of catalyst under the same reaction condition. These different morphologies at the same growth time were due to the different areal density rather than to the length of CNTs. With increasing nominal thickness of catalyst, the catalyst particles changed in diameter while their areal density remained relatively almost constant. The change in diameter possibly affected the number ratio of active catalyst particles to the whole particles, which in turn affected the areal density of CNTs and yielded the various morphologies. Longer growth time increased the CNT length, which caused further change in CNT morphologies from individuals to grasses and grasses to forests.

  4. Thinner regions of intracranial aneurysm wall correlate with regions of higher wall shear stress: a 7.0 tesla MRI

    Science.gov (United States)

    Blankena, Roos; Kleinloog, Rachel; Verweij, Bon H.; van Ooij, Pim; ten Haken, Bennie; Luijten, Peter R.; Rinkel, Gabriel J.E.; Zwanenburg, Jaco J.M.

    2016-01-01

    Purpose To develop a method for semi-quantitative wall thickness assessment on in vivo 7.0 tesla (7T) MRI images of intracranial aneurysms for studying the relation between apparent aneurysm wall thickness and wall shear stress. Materials and Methods Wall thickness was analyzed in 11 unruptured aneurysms in 9 patients, who underwent 7T MRI with a TSE based vessel wall sequence (0.8 mm isotropic resolution). A custom analysis program determined the in vivo aneurysm wall intensities, which were normalized to signal of nearby brain tissue and were used as measure for apparent wall thickness (AWT). Spatial wall thickness variation was determined as the interquartile range in AWT (the middle 50% of the AWT range). Wall shear stress was determined using phase contrast MRI (0.5 mm isotropic resolution). We performed visual and statistical comparisons (Pearson’s correlation) to study the relation between wall thickness and wall shear stress. Results 3D colored AWT maps of the aneurysms showed spatial AWT variation, which ranged from 0.07 to 0.53, with a mean variation of 0.22 (a variation of 1.0 roughly means a wall thickness variation of one voxel (0.8mm)). In all aneurysms, AWT was inversely related to WSS (mean correlation coefficient −0.35, P<0.05). Conclusions A method was developed to measure the wall thickness semi-quantitatively, using 7T MRI. An inverse correlation between wall shear stress and AWT was determined. In future studies, this non-invasive method can be used to assess spatial wall thickness variation in relation to pathophysiologic processes such as aneurysm growth and –rupture. PMID:26892986

  5. Comparison of central corneal thickness measured by Lenstar LS900, OrbscanⅡ and ultrasonic pachmetry

    Directory of Open Access Journals (Sweden)

    Hong-Tao Zhang

    2013-09-01

    Full Text Available AIM: To investigate the difference of central corneal thickness(CCTmeasured by Lenstar LS900, OrbscahⅡ system and ultrasonic pachmetry, and to evaluate the correlation and consistency of the results for providing a theoretical basis for clinical application.METHODS: The mean value of CCT in 70 eyes of 35 patients measured three times by Lenstar LS900, OrbscahⅡ system and ultrasonic pachmetry underwent statistical analysis. The difference of CCT was compared, and the correlation and consistency of three measurements were analyzed to provide theoretical basis for clinical application. CCT values measured by different methods were analyzed with randomized block variance analysis. LSD-t test was used for pairwise comparison between groups. The correlation of three measurement methods were analyzed by linear correlation analysis, and Bland-Altman was used to analyze the consistency.RESULTS: The mean CCT values measured by Lenstar LS900, OrbscanⅡ and ultrasonic pachmetry were 542.75±40.06, 528.74±39.59, 538.54±40.93μm, respectively. The mean difference of CCT measurement was 4.21±8.78μm between Lenstar LS900 and ultrasonic pachmetry, 14.01±13.39μm between Lenstar LS900 and Orbscan Ⅱ, 9.8±10.57μm between ultrasonic pachmetry and Orbscan Ⅱ. The difference was statistically significant(PP>0.05: There was positive correlation between CCT with Lenstar LS900 and ultrasonic pachmetry(r=0.977, 0.944; PCONCLUSION: There are excellent correlation among Lenstar LS900, Orbscan Ⅱ and ultrasonic pachmetry. Lenstar LS900 can be used as CCT non-contact measurement tool.

  6. Comparison Study on the Exact Dynamic Stiffness Method for Free Vibration of Thin and Moderately Thick Circular Cylindrical Shells

    Directory of Open Access Journals (Sweden)

    Xudong Chen

    2016-01-01

    Full Text Available Comparison study on free vibration of circular cylindrical shells between thin and moderately thick shell theories when using the exact dynamic stiffness method (DSM formulation is presented. Firstly, both the thin and moderately thick dynamic stiffness formulations are examined. Based on the strain and kinetic energy, the vibration governing equations are expressed in the Hamilton form for both thin and moderately thick circular cylindrical shells. The dynamic stiffness is assembled in a similar way as that in classic skeletal theory. With the employment of the Wittrick-Williams algorithm, natural frequencies of circular cylindrical shells can be obtained. A FORTRAN code is written and used to compute the modal characteristics. Numerical examples are presented, verifying the proposed computational framework. Since the DSM is an exact approach, the advantages of high accuracy, no-missing frequencies, and good adaptability to various geometries and boundary conditions are demonstrated. Comprehensive parametric studies on the thickness to radius ratio (h/r and the length to radius ratio (L/r are performed. Applicable ranges of h/r are found for both thin and moderately thick DSM formulations, and influences of L/r on frequencies are also investigated. The following conclusions are reached: frequencies of moderately thick shells can be considered as alternatives to those of thin shells with high accuracy where  h/r is small and L/r is large, without any observation of shear locking.

  7. Comparison of corneal flap thickness using a FS200 femtosecond laser and a moria SBK microkeratome

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2014-04-01

    Full Text Available AIM: To evaluate differences in flap thickness resulting from use of an Alcon Wavelight FS200 femtosecond laser and a MORIA SBK microkeratome when making a 110-μm-thick corneal flap and to identify the potential factors that affect corneal flap thickness.METHODS: A prospective case study was performed on 120 eyes of 60 patients who were divided into two groups for LASIK, each group consisting of 60 eyes (30 patients. The corneal flaps were created using an Alcon Wavelight FS200 femtosecond laser or a MORIA SBK microkeratome. The central corneal flap thickness was calculated by subtraction pachymetry. Age, central corneal thickness (CCT, spherical equivalent refraction, mean keratometry, and corneal diameter were recorded preoperatively for analysis.RESULTS: Cutting of all flaps was easily performed without intraoperative complications. In the Alcon Wavelight FS200 femtosecond lasergroup, the mean right and left corneal flap thicknesses were 114.0±6.6 μm (range:98-126 and 111.4±7.6 μm (range:98-122, respectively. The difference (2.6±9.1 μm in the corneal flap thickness between the right and left eyes was not significant (t=1.59, P=0.12. Stepwise regression analysis indicated that the resulting corneal flap thickness was unrelated to the patient’s age, preoperative CCT, spherical equivalent refraction, mean keratometry, or corneal diameter. In the MORIA SBK microkeratome group, the mean right and left corneal flap thicknesses were 110.6±7.4 μm (range:97-125 μm and 108.2±6.1 μm (range:78-123 μm, respectively. The difference in the corneal flap thickness between the right and left eyes (2.4±6.5μm was not significant (t=2.039, P=0.0506. The corneal flap thickness was positively correlated with the preoperative CCT through stepwise regression analysis (r=0.297, P=0.021. The corneal flap thickness was not related to age, spherical equivalent refraction, mean keratometry, or corneal diameter. The corneal flap thickness was estimated

  8. Behaviour of a new composite mesh for the repair of full-thickness abdominal wall defects in a rabbit model.

    Directory of Open Access Journals (Sweden)

    Gemma Pascual

    Full Text Available INTRODUCTION: Composite biomaterials designed for the repair of abdominal wall defects are composed of a mesh component and a laminar barrier in contact with the visceral peritoneum. This study assesses the behaviour of a new composite mesh by comparing it with two latest-generation composites currently used in clinical practice. METHODS: Defects (7x5cm created in the anterior abdominal wall of New Zealand White rabbits were repaired using a polypropylene mesh and the composites: Physiomesh(TM; Ventralight(TM and a new composite mesh with a three-dimensional macroporous polyester structure and an oxidized collagen/chitosan barrier. Animals were sacrificed on days 14 and 90 postimplant. Specimens were processed to determine host tissue incorporation, gene/protein expression of neo-collagens (RT-PCR/immunofluorescence, macrophage response (RAM-11-immunolabelling and biomechanical resistance. On postoperative days 7/14, each animal was examined laparoscopically to quantify adhesions between the visceral peritoneum and implant. RESULTS: The new composite mesh showed the lowest incidence of seroma in the short term. At each time point, the mesh surface covered with adhesions was greater in controls than composites. By day 14, the implants were fully infiltrated by a loose connective tissue that became denser over time. At 90 days, the peritoneal mesh surface was lined with a stable mesothelium. The new composite mesh induced more rapid tissue maturation than Physiomesh(TM, giving rise to a neoformed tissue containing more type I collagen. In Ventralight(TM the macrophage reaction was intense and significantly greater than the other composites at both follow-up times. Tensile strengths were similar for each biomaterial. CONCLUSIONS: All composites showed optimal peritoneal behaviour, inducing good peritoneal regeneration and scarce postoperative adhesion formation. A greater foreign body reaction was observed for Ventralight(TM. All composites induced

  9. A thick-walled sphere rotating in a uniform magnetic field: The next step to de-spin a space object

    Science.gov (United States)

    Nurge, Mark A.; Youngquist, Robert C.; Caracciolo, Ryan A.; Peck, Mason; Leve, Frederick A.

    2017-08-01

    Modeling the interaction between a moving conductor and a static magnetic field is critical to understanding the operation of induction motors, eddy current braking, and the dynamics of satellites moving through Earth's magnetic field. Here, we develop the case of a thick-walled sphere rotating in a uniform magnetic field, which is the simplest, non-trivial, magneto-statics problem that leads to complete closed-form expressions for the resulting potentials, fields, and currents. This solution requires knowledge of all of Maxwell's time independent equations, scalar and vector potential equations, and the Lorentz force law. The paper presents four cases and their associated experimental results, making this topic appropriate for an advanced student lab project.

  10. 冷弯厚壁矩形型钢管冷弯效应%Strain hardening of thick-walled cold formed steel rectangular hollow section

    Institute of Scientific and Technical Information of China (English)

    胡盛德; 李立新; 周家林

    2011-01-01

    针对断面规格为口200×300×9.2的冷弯厚壁矩形型钢管,进行了平板、弯角、相应母材和短柱试件的力学性能试验.结合冷弯生产工艺,分析了平板、弯角试件力学性能随冷弯道次的变化规律,并与相关厚壁型钢冷作硬化效应作了比较.运用国内外冷弯型钢设计规范和相关文献中的修正公式,对该厚壁冷弯方形型钢全截面强度进行了设计和对比分析.结果表明:国内薄壁和国外厚壁公式都不可直接用于本冷弯厚壁矩形型钢强度设计,国外公式更偏于危险;魏氏体组织是造成带焊缝板件强度高而塑性差的主要原因;焊接热使板件受到低温"退火"而强度降低,从而导致两竖直侧平板件强度甚至低于母材.%Tests on mechanical characteristics of the flat portion, corner portion, virgin steel and full section stub column were conducted for the thick-walled cold formed steel tube with sectional dimension of 200mm × 300mm × 9.2mm.Variation in mechnical properties of the flat and corner portion with passes were analyzed according to the cold forming technology.Strain hardening of thick-walled steel was compared with that in reference [7].The increase of yield strength resulted from the cold-forming work were calculated based on the specifications in North America, China and reference[7]respectively.The results show that both of the first two specifications don't fit for the thick-walled cold formed steel.The specification abroad for prediction of thick-wall cold formed steel stub column is more dangerous than Chinese specification.Widmanstatten microstructure formed in material is the ultimate cause of high strength and low plasticity of the flat portion specimens with welding line.The sweating heat reduces the strength of plate specimens and even results in that the strength of the flat portion bilateral is lower than that of the virgin steel.

  11. Extremal states of energy of a double-layered thick-walled tube - application to residually stressed arteries.

    Science.gov (United States)

    Waffenschmidt, Tobias; Menzel, Andreas

    2014-01-01

    Various biological tissues are designed to optimally support external loads for complex geometries and mechanobiological structures. This results in complex microstructures of such materials. The design of, for instance, (healthy) arteries, which are in the focus of this work, is characterised by a residually stressed fibre-reinforced multi-layered composite with highly non-linear elastic response. The complex interaction of material properties with the geometry and residual stress effects enables the optimal support under different blood pressures, respectively blood flow, within the vessel. The fibres reinforcing the arterial wall, as well as residual stresses present in the vessel, strongly influence its overall behaviour and performance. Turn-over and remodelling processes of the collagenous fibres occurring in the respective layers - either resulting from natural growth phenomena or from artificially induced changes in loading condition such as stent deployment - support the optimisation of the multi-layered composite structure of arteries for the particular loading conditions present in the artery. Within this contribution, the overall energetic properties of an artery are discussed by means of the inflation, bending and extension of a double-layered cylindrical tube. Different states of residual stresses and different fibre orientations are considered so that, for instance, representative fibre angles that result in extremal states of the total potential energy can be identified. In view of turn-over and remodelling processes, these orientations are considered to constitute preferred directions of fibre alignment. In summary, the main goal of this work is to calculate optimal material, structural and loading parameters by concepts of energy-minimisation. Several numerical studies show that the obtained values - such as the fibre orientations, the residual axial stretch and the opening angle - are in good agreement with respective physiological parameters

  12. Experimental and Numerical Investigation of the Effect of Process Conditions on Residual Wall Thickness and Cooling and Surface Characteristics of Water-Assisted Injection Molded Hollow Products

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    Hyungpil Park

    2015-01-01

    Full Text Available Recently, water-assisted injection molding was employed in the automobile industry to manufacture three-dimensional hollow tube-type products with functionalities. However, process optimization is difficult in the case of water-assisted injection molding because of the various rheological interactions between the injected water and the polymer. In this study, the boiling phenomenon that occurs because of the high melt temperature when injecting water and the molding characteristics of the hollow section during the water-assisted injection process were analyzed by a water-assisted injection molding analysis. In addition, the changes in the residual wall thickness accompanying changes in the process conditions were compared with the analysis results by considering water-assisted injection molding based on gas-assisted injection molding. Furthermore, by comparing the cooling characteristics and inner wall surface qualities corresponding to the formation of the hollow section by gas and water injections, a water-assisted injection molding technique was proposed for manufacturing hollow products with functionality.

  13. Novel synthesis of thick wall coatings of titania supported Bi poisoned Pd catalysts and application in selective hydrogenation of acetylene alcohols in capillary microreactors.

    Science.gov (United States)

    Cherkasov, Nikolay; Ibhadon, Alex O; Rebrov, Evgeny V

    2015-04-21

    Catalysis in microreactors allows reactions to be performed in a very small volume, reducing the environmental problems and greatly intensifying the processes through easy pressure control and the elimination of heat- and mass-transfer limitations. In this study, we report a novel method for the controlled synthesis of micrometre-thick mesoporous TiO2 catalytic coatings on the walls of long channels (>1 m) of capillary microreactors in a single deposition step. The method uses elevated temperature and introduces a convenient control parameter of the deposition rate (displacement speed controlled by a stepper motor), which allows deposition from concentrated and viscous sols without channel clogging. A capillary microreactor wall-coated with titania supported Bi-poisoned Pd catalyst was obtained using the method and used for the semihydrogenation of 2-methyl-3-butyn-2-ol providing 93 ± 1.5% alkene yield for 100 h without deactivation. Although the coating method was applied only for TiO2 deposition, it is nonetheless suitable for the deposition of volatile sols.

  14. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry and Orbscan II Corneal Topography and Evaluation of Ultrasonic Pachymetry Repeatability

    OpenAIRE

    Semra Tiryaki Demir; Mahmut Odabaşı; Mehmet Ersin Oba; Ayşe Burcu Dirim; Efe Can; Orhan Kara

    2014-01-01

    Objectives: Comparison of central corneal thickness (CCT) measurements by ultrasonic pachymetry and Orbscan II corneal topography and evaluation of ultrasonic pachymetry repeatability for same observer. Materials and Methods: The study included 132, 82, and 80 eyes of 66 patients with primary open-angle glaucoma (POAG), 41 patients with ocular hypertension (OHT), and 40 controls, respectively. All subjects were subjected to routine ophthalmic examination. Orbscan II (Bausch&Lomb) ...

  15. Comparison of ultrasonography and skinfold measurements of subcutaneous fat thickness in the evaluation of body composition

    OpenAIRE

    Akyer, Şahika Pınar; Adıgüzel, Esat; Sabir, Nuran; Akdoğan, Ilgaz; Yılmaz, Birsen; yonguç, gökşin nilüfer

    2014-01-01

    Objectives:To determine the amount of body fat tissue with skinfold thickness measurements is a common method to estimate the body composition. The other method used for this purpose is ultrasonography which is expensive and needs specialization to apply. In this study, validity of skinfold thickness measurements was investigated using ultrasonography. Methods: One hundred adult volunteers (50 males and 50 females) were used in this study. The ages of the subjects were 20to 70, selected as10 ...

  16. Hyaline cartilage thickness in radiographically normal cadaveric hips: comparison of spiral CT arthrographic and macroscopic measurements.

    Science.gov (United States)

    Wyler, Annabelle; Bousson, Valérie; Bergot, Catherine; Polivka, Marc; Leveque, Eric; Vicaut, Eric; Laredo, Jean-Denis

    2007-02-01

    To assess spiral multidetector computed tomographic (CT) arthrography for the depiction of cartilage thickness in hips without cartilage loss, with evaluation of anatomic slices as the reference standard. Permission to perform imaging studies in cadaveric specimens of individuals who had willed their bodies to science was obtained from the institutional review board. Two independent observers measured the femoral and acetabular hyaline cartilage thickness of 12 radiographically normal cadaveric hips (from six women and five men; age range at death, 52-98 years; mean, 76.5 years) on spiral multidetector CT arthrographic reformations and on coronal anatomic slices. Regions of cartilage loss at gross or histologic examination were excluded. CT arthrographic and anatomic measurements in the coronal plane were compared by using Bland-Altman representation and a paired t test. Differences between mean cartilage thicknesses at the points of measurement were tested by means of analysis of variance. Interobserver and intraobserver reproducibilities were determined. At CT arthrography, mean cartilage thickness ranged from 0.32 to 2.53 mm on the femoral head and from 0.95 to 3.13 mm on the acetabulum. Observers underestimated cartilage thickness in the coronal plane by 0.30 mm +/- 0.52 (mean +/- standard error) at CT arthrography (P cartilage thicknesses at the different measurement points was significant for coronal spiral multidetector CT arthrography and anatomic measurement of the femoral head and acetabulum and for sagittal and transverse CT arthrography of the femoral head (P cartilage thickness from the periphery to the center of the joint ("gradients") were found by means of spiral multidetector CT arthrography and anatomic measurement. Spiral multidetector CT arthrography depicts cartilage thickness gradients in radiographically normal cadaveric hips. (c) RSNA, 2007.

  17. 易拉罐壁厚的随机分布对其强度和刚度的影响%Influences of Randomly Distributed Wall Thickness of Beverage Can on Its Strength and Stiffness

    Institute of Scientific and Technical Information of China (English)

    许京荆; 王志陵; 吴益敏

    2001-01-01

    This paper describes the research undertaken on the strength and stiffness of fluctuation on the wall thickness of steel beverage cans using the Monte-Carlo stochastic finite element method. Sample distributions were firstly assumed and then proven using the data observations of the wall thickness, the APDL language was then applied, and the stresses and displacements of the can were calculated by using the ANSYS software. It is concluded that the structural reliability of a steel-making beverage can be estimated accurately.

  18. Cortical thickness estimation in longitudinal stroke studies: A comparison of 3 measurement methods.

    Science.gov (United States)

    Li, Qi; Pardoe, Heath; Lichter, Renee; Werden, Emilio; Raffelt, Audrey; Cumming, Toby; Brodtmann, Amy

    2015-01-01

    There is considerable controversy about the causes of cognitive decline after stroke, with evidence for both the absence and coexistence of Alzheimer pathology. A reduction in cortical thickness has been shown to be an important biomarker for the progression of many neurodegenerative diseases, including Alzheimer's disease (AD). However, brain volume changes following stroke are not well described. Cortical thickness estimation presents an ideal way to detect regional and global post-stroke brain atrophy. In this study, we imaged a group of patients in the first month after stroke and at 3 months. We compared three methods of estimating cortical thickness on unmasked images: one surface-based (FreeSurfer) and two voxel-based methods (a Laplacian method and a registration method, DiRecT). We used three benchmarks for our analyses: accuracy of segmentation (especially peri-lesional performance), reproducibility, and biological validity. We found important differences between these methods in cortical thickness values and performance in high curvature areas and peri-lesional regions, but similar reproducibility metrics. FreeSurfer had less reliance on manual boundary correction than the other two methods, while reproducibility was highest in the Laplacian method. A discussion of the caveats for each method and recommendations for use in a stroke population is included. We conclude that both surface- and voxel-based methods are valid for estimating cortical thickness in stroke populations.

  19. Comparison of RNFL thickness and RPE-normalized RNFL attenuation coefficient for glaucoma diagnosis

    Science.gov (United States)

    Vermeer, K. A.; van der Schoot, J.; Lemij, H. G.; de Boer, J. F.

    2013-03-01

    Recently, a method to determine the retinal nerve fiber layer (RNFL) attenuation coefficient, based on normalization on the retinal pigment epithelium, was introduced. In contrast to conventional RNFL thickness measures, this novel measure represents a scattering property of the RNFL tissue. In this paper, we compare the RNFL thickness and the RNFL attenuation coefficient on 10 normal and 8 glaucomatous eyes by analyzing the correlation coefficient and the receiver operator curves (ROCs). The thickness and attenuation coefficient showed moderate correlation (r=0.82). Smaller correlation coefficients were found within normal (r=0.55) and glaucomatous (r=0.48) eyes. The full separation between normal and glaucomatous eyes based on the RNFL attenuation coefficient yielded an area under the ROC (AROC) of 1.0. The AROC for the RNFL thickness was 0.9875. No statistically significant difference between the two measures was found by comparing the AROC. RNFL attenuation coefficients may thus replace current RNFL thickness measurements or be combined with it to improve glaucoma diagnosis.

  20. 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.

  1. Lifetime assessment of thick-walled components made of nickel-base alloys under near-service loading conditions; Lebensdauerbewertung dickwandiger Bauteile aus Nickelbasislegierungen unter betriebsnahen Beanspruchungen

    Energy Technology Data Exchange (ETDEWEB)

    Hueggenberg, Daniel

    2015-11-06

    and the transmission electron microscope for the base raw material, the creep and creep-fatigue exposed material. For the classification the investigation results were compared to the results of the other projects and no differences could be identified. For the description of the deformation and damage behavior under creep-fatigue loading with finite elements simulations a viscoplastic deformation model with an integrated damage model of Lemaitre was used. The material dependent model parameters were fitted under consideration of the basis characterization test results of the Alloy 617 mod. and Alloy 263. All basis characterization tests are simulated with finite elements to classify the parameter fittings. The verification of the fitted material models was carried out by simulations of the complex lab tests. From the comparison of the simulation and test results it is obvious that the deformation and damage behavior can be reproduced with the used material model in a good manner. With finite element simulations of complex thick-walled components (header, formed part) under realistic thermal and mechanic loading conditions could be shown that the viscoplastic material model fitted for the Alloy 617 mod. and Alloy 263 is able to predict the locations of the maximum loadings and the lifetime until the first cracks appear. This could be confirmed by dye penetrant testing on the one hand and destructive investigations of two fracture surfaces of the header on the other hand. Additionally the approaches of the European DIN EN 12952-3/4, the American ASME Section III Division 1 Subsection NH, the French RCC-MR RB 3262.12 and the British R5 recommendations Volume 2/3 are used to predict the lifetimes. It can be seen that the approaches of ASME and RCC-MR provide very conservative predictions and that the approaches of R5 and DIN EN 12952 provide non-conservative predictions. These results lead to the conclusion that no approach of the standards/recommendation is suitable for

  2. Comparison of scar thickness measurements using trans-vaginal sonography and MRI in cases of pregnancy with previous caesarean section. Do they correlate with actual scar thickness?

    Science.gov (United States)

    Singh, N; Tripathi, R; Mala, Y M; Dixit, R; Tyagi, S; Batra, A

    2013-11-01

    The aim of this study was to evaluate scar thickness in cases of pregnancy with previous caesarean section, by trans-vaginal sonography (TVS) and magnetic resonance imaging (MRI), and to correlate precision of radiologically-measured scar thickness with actual measurement of scar thickness. A total of 35 pregnant patients with previous caesarean section planned for elective caesarean section, were evaluated prospectively. Their scar thickness was measured by TVS and MRI on the day of elective repeat caesarean section. These measurements were correlated with each other and with scar thickness measured during elective repeat caesarean section by using a caliper. The correlation coefficients between scar thickness measured by TVS and MRI with peroperative evaluation with a caliper, were +0.72 and +0.59, respectively. The study concluded that as MRI is a costlier modality and TVS has better correlation coefficient with actual scar thickness, TVS can be considered to be the better modality for antenatal scar thickness measurement.

  3. Correlation of left ventricular wall thickness, heart mass, serological parameters and late gadolinium enhancement in cardiovascular magnetic resonance imaging of myocardial inflammation in an experimental animal model of autoimmune myocarditis.

    Science.gov (United States)

    Kromen, Wolfgang; Korkusuz, Huedayi; Korkusuz, Yuecel; Esters, Philip; Bauer, Ralf W; Huebner, Frank; Lindemayr, Sebastian; Vogl, Thomas J

    2012-12-01

    For a definitive diagnosis of myocarditis, different strategies like analysis of late gadolinium enhancement (LGE) in cardiovascular magnetic resonance imaging (CMR) up to invasive endomyocardial biopsy have been applied. The objective of the study was to investigate inflammatory changes like left ventricular wall thickening and increase of ventricular mass and to quantitatively analyse their correlation with extent and localisation of myocardial damage in CMR and with subsequent changes of serological markers in an animal model of an experimental autoimmune myocarditis (EAM). In the current study, an EAM was induced in 10 male Lewis rats, 10 rats served as control. On day 21, animals were examined with four CMR protocols to assess the extent of LGE in a 12 segment model of the rat heart. Left myocardial wall thickness and mass and histological grade of inflammation were measured to determine localisation and severity of the induced myocarditis. Depending on the CMR sequence, LGE was mostly found in the left anterior (9.6%) and left lateral (8.7%) myocardial wall segments. Wall thickness correlated with the LGE area in CMR imaging and the histopathological severity of myocarditis for the left lateral myocardial wall segment. In a similar way, the heart mass correlated to the extent of LGE for the left lateral segment. We conclude that in our animal model left ventricular wall thickness and mass reflect the severity of myocardial changes in myocarditis and that the EAM rat model is well suited for further investigations of myocarditis.

  4. A Comparison of Three Different Thick Epinucleus Removal Techniques in Cataract Surgery.

    Science.gov (United States)

    Hwang, Ho Sik; Lim, Byung-Su; Kim, Man Soo; Kim, Eun Chul

    2017-01-01

    To compare the outcomes of cataract surgery performed with three different types of the epinucleus removal techniques (safe boat, infusion/aspiration (I/A) cannulas, and phacoemulsification tip). Ninety eyes with thick adhesive epinuclei were randomly subdivided into three groups according to epinucleus removal technique: epinucleus floating (safe boat) technique, 30 patients; I/A tip, 30 patients; and phaco tip, 30 patients. Intraoperative measurements included ultrasound time (UST), mean cumulative dissipated ultrasound energy (CDE), and balanced salt solution (BSS) use. Clinical measurements were made preoperatively, and at one day, one month and two months postoperatively, including the best corrected visual acuity (BCVA), the central corneal thickness (CCT), and the endothelial cell count (ECC). Intraoperative measurements showed significantly less UST, CDE, and BSS use in the safe boat group than in the phaco tip groups (p phaco tip groups at two months post-cataract surgery (p phaco tip techniques in cases with thick epinucleus.

  5. HYBRID LAYER THICKNESS IN PRIMARY AND PERMANENT TEETH – A COMPARISON BETWEEN TOTAL ETCH ADHESIVES

    Directory of Open Access Journals (Sweden)

    Natalia Gateva

    2012-05-01

    Full Text Available Purpose: The aim this study is to compare the hybrid layer thickness and its micromorphological characteristics in samples from primary and permanent teeth following application of total etch adhesives.Materials and methods: On intact specimens of 20 primary and 10 permanent teeth was created flat dentin surfaces. The patterns were divided in 6 groups. Two different total etch adhesive systems were used – one tree steps (OptiBond, Kerr and one two steps (Exite, VivaDent. In groups 3, 4, 5 and 6 recommended etching time was used - 15 s, in groups 1 and 2 the etching time was reduced to 7 s. After applying the adhesive, resin composite build-ups were constructed. Thus restored samples are stored in saline solution for 24 hours at temperature 37 C. Then they are subjected to thermal stress in temperature between 5 C to 55 C for 1,500 cycles and to masticatory stress – 150,000 cycles with force 100 N in intervals of 0.4 s. After that the teeth are cut through the middle in medio-distal direction with a diamond disc. SEM observation was done to investigate the thickness of the hybrid layer and the presence of microgaps. Statistical analysis was performed with ANOVA and Tukey׳s tests.Results: SEM observation showed significant differences of the hybrid layer thickness between primary and permanent teeth under equal conditions and after different etching time. Group 6 presented the highest average thickness 8.85 μ and group 1 the lowest average in hybrid layer 3.74 μ.Conclusion: In primary teeth the hybrid layer thickness increases with the increased etching time. The hybrid layer thickness in primary teeth is greater than that of the hybrid layer in permanent teeth under equal conditions. For primary teeth it is more appropriate to reduce the etching time to 7s to obtain a hybrid layer with better quality

  6. Comparison between TRM and FRP strengthening systems at preventing buckling failure of brick masonry walls

    Directory of Open Access Journals (Sweden)

    Bernat-Maso, E.

    2016-09-01

    Full Text Available Fibre Reinforced Polymer (FRP and Textile Reinforced Mortar (TRM have been studied, compared and applied to strengthen brick masonry walls. The comparison of their performance against second order bending effects is addressed in this paper for the first time. Experimental and analytical data from previous researches and new analytical data for TRM cases are summarised, ordered and systematically compared to analyse the structural response of strengthened brick masonry walls. The results show a similar performance for both systems in terms of load bearing capacity and in-plane response. However, TRM strengthened cases showed greater lateral deformation than FRP ones.Materiales tipo Fibre Reinforced Polymer (FRP y Textile Reinforced Mortar (TRM han sido estudiados, comparados y aplicados para reforzar muros de fábrica de ladrillo. La comparación de su comportamiento frente a efectos de flexión de segundo orden se abordada en este artículo por primera vez. Datos experimentales y analíticos de investigaciones previas y nuevos datos analíticos para los casos de TRM son resumidos, ordenados y sistemáticamente comparados para analizar la respuesta estructural de los muros de fábrica de ladrillo reforzados. Los resultados muestran un comportamiento similar de los dos sistemas respecto su capacidad de carga y su respuesta en el plano. Los casos reforzados con TRM mostraron desplazamientos laterales superiores a los reforzados con FRP.

  7. 机械自紧厚壁圆筒塑性半径的计算%Calculation of Plastic Radius for Thick-Walled Cylinders of Mechanical Autofrettage

    Institute of Scientific and Technical Information of China (English)

    常列珍; 潘玉田; 马新谋; 潘丹阳

    2011-01-01

    机械自紧是依靠冲头同身管内径的过盈量使身管内壁产生塑性变形,提高承载能力,达到自紧的目的.准确建立冲头过盈量与塑性半径之间的关系,才能准确地预测自紧度.为此,利用合理的简化假设,通过对冲头进行弹性分析和对厚壁圆筒进行塑性分析,利用机械自紧在加载过程中冲头圆柱段和厚壁圆筒接触处径向应力相等这一边界条件,推导出了过盈量与塑性半径之间的计算公式,从该公式可直接由过盈量求出塑性半径,由塑性半径便可预测出机械自紧厚壁圆筒的自紧度.为了验证公式的正确性,对10种不同过盈量的机械自紧过程进行了数值模拟,理论计算与数值模拟的结果进行比较,发现理论计算结果与数值模拟的结果比较吻合.%The swage autofrettage barrel is formed depending on the depth of plastic deformation since the diameter of the tool is slightly larger than the barrel inner diameter. The barrel forged in this way can withstand large internal pressures. In order to calculate the degree of autofrettage, the relation between the interference and the plastic radius must be accurately investigated. In loading process, the radial stress of cylindrical section of swage and thick-walled cylinder contact section is equal. By using this boundary condition, an elastic analysis for swage and a plastic analysis for thick-walled cylinder were conducted, and formulas were obtained for calculating excess and plastic radius. Knowing interference, the plastic radius could be calculated directly and the tight tolerance could be pre-estimated by using the plastic radius. To verify the accuracy of the formula, the process of mechanical autofrettage with ten kind different interferences were simulated. Calculated plastic radius agreed well with the results of numerical simulation.

  8. Right ventricular relative wall thickness as a predictor of outcomes and of right ventricular reverse remodeling for patients with pulmonary hypertension.

    Science.gov (United States)

    Sano, Hiroyuki; Tanaka, Hidekazu; Motoji, Yoshiki; Fukuda, Yuko; Mochizuki, Yasuhide; Hatani, Yutaka; Matsuzoe, Hiroki; Hatazawa, Keiko; Shimoura, Hiroyuki; Ooka, Junichi; Ryo-Koriyama, Keiko; Nakayama, Kazuhiko; Matsumoto, Kensuke; Emoto, Noriaki; Hirata, Ken-Ichi

    2017-03-01

    Mid-term right ventricular (RV) reverse remodeling after treatment in patients with pulmonary hypertension (PH) is associated with long-term outcome as well as baseline RV remodeling. However, baseline factors influencing mid-term RV reverse remodeling after treatment and its prognostic capability remain unclear. We studied 54 PH patients. Mid-term RV remodeling was assessed in terms of the RV area, which was traced planimetrically at the end-systole (RVESA). RV reverse remodeling was defined as a relative decrease in the RVESA of at least 15% at 10.2 ± 9.4 months after treatment. Long-term follow-up was 5 years. Adverse events occurred in ten patients (19%) and mid-term RV reverse remodeling after treatment was observed in 37 (69%). Patients with mid-term RV reverse remodeling had more favorable long-term outcomes than those without (log-rank: p = 0.01). Multivariate logistic regression analysis showed that RV relative wall thickness (RV-RWT), as calculated as RV free-wall thickness/RV basal linear dimension at end-diastole, was an independent predictor of mid-term RV reverse remodeling (OR 1.334; 95% CI, 1.039-1.713; p = 0.03). Moreover, patients with RV-RWT ≥0.21 showed better long-term outcomes than did those without (log-rank p = 0.03), while those with RV-RWT ≥0.21 and mid-term RV reverse remodeling had the best long-term outcomes. Patients with RV-RWT <0.21 and without mid-term RV reverse remodeling, on the other hand, had worse long-term outcomes than other sub-groups. In conclusions, RV-RWT could predict mid-term RV reverse remodeling after treatment in PH patients, and was associated with long-term outcomes. Our finding may have clinical implications for better management of PH patients.

  9. Comparisons of the Various Partial-Thickness Rotator Cuff Tears on MR Arthrography and Arthroscopic Correlation

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Kyung Ah; Kim, Min Sung; Kim, Young Joo [Catholic University of Korea Uijeongbu St.Mary' s Hospital, Uijeongbu (Korea, Republic of)

    2010-10-15

    To assess the diagnostic performance of MR arthrography in the diagnosis of the various types of partial-thickness rotator cuff tears by comparing the MR imaging findings with the arthroscopic findings. The series of MR arthrography studies included 202 patients consisting of 100 patients with partial-thickness rotator cuff tears proved by arthroscopy and a control group of 102 patients with arthroscopically intact rotator cuffs, which were reviewed in random order. At arthroscopy, 54 articularsided, 26 bursal-sided, 20 both articular- and bursal-sided partial-thickness tears were diagnosed. The MR arthrographies were analyzed by two radiologists for articular-sided tears, bursal-sided tears, and both articular- and bursal-sided tears of the rotator cuff. The sensitivity and specificity of each type of partial-thickness tears were determined. Kappa statistics was calculated to determine the interand intra-observer agreement of the diagnosis of partial-thickness rotator cuff tears. The sensitivity and specificity of the various types of rotator cuff tears were 85% and 90%, respectively for articular-sided tears, 62% and 95% for bursal- sided tears, as well as 45% and 99% for both articular- and bursal-sided tears. False-negative assessments were primarily observed in the diagnosis of bursal-sided tears. Conversely, both articular- and bursal-sided tears were overestimated as full-thickness tears. Inter-observer agreement was excellent for the diagnosis of articular-sided tears (k = 0.70), moderate (k = 0.59) for bursal-sided tears, and fair (k = 0.34) for both articular- and bursal-sided tears, respectively. Intra-observer agreement for the interpretation of articular- and bursal-sided tears was excellent and good, respectively, whereas intra-observer agreement for both articular- and bursal-sided tears was moderate. MR arthrography is a useful diagnostic tool for partial-thickness rotator cuff tears, but has limitations in that it has low sensitivity in bursal- and

  10. Comparison of visual evoked potentials and retinal nerve fibre layer thickness in Alzheimer‘s disease

    Directory of Open Access Journals (Sweden)

    Robert eKromer

    2013-12-01

    Full Text Available IntroductionAlzheimer‘s disease is a long term progressive neurodegenerative disease and might affect the retinal nerve fibre layer thickness of the eye. There is increasing evidence that visual evoked potentials, which are an objective way to indicate visual field loss, might be affected by the disease as well.Material and Methods22 patients (mean age: 75.9 ± 6.1 years; 14 women with mild-to-moderate Alzheimer‘s disease and 22 sex-matched healthy patients were examined. We compared the use of visual evoked potentials and retinal nerve fibre layer thickness using latest high-resolution spectral domain optical coherence tomography with eye-tracking capabilities for optimised peripapillary scan centring for the first time in Alzheimer‘s disease patients.ResultsThe mean MMSE score was 22.59 ± 5.47 in the Alzheimer‘s disease group, and did not significantly correlate with the visual evoked potentials latencies. We found no significant difference between the visual evoked potentials latencies of the Alzheimer‘s disease patients and those of the control patients. No peripapillary sector of the retina had a retinal nerve fibre layer thickness significantly correlated with the visual evoked potentials latencies.DiscussionWe demonstrated that pattern visual evoked potentials did not show any significant correlation despite subtle loss in retinal nerve fibre layer thickness. It remains open whether additional flash visual evoked potentials combined with retinal nerve fibre layer thickness analysis may be useful in diagnosing Alzheimer‘s disease, particularly for mild-to-moderate stages of the disease.

  11. Comparison of Microleakage and Thickness of Resin Cement in Ceramic Inlays with Various Temperatures

    Directory of Open Access Journals (Sweden)

    Homayoun Alaghemand

    2014-03-01

    Full Text Available Background and aims. Microleakage is still one of the major problems of composite-based restorations. This study compared the microleakage and thickness of resin cement in ceramic inlays with various temperatures. Materials and methods. Class V cavities were prepared on the buccal and lingual aspects of thirty human molars with occlusal margins in enamel and gingival margins in dentin (3 mm wide, 5 mm long and 2 mm deep. Laboratory-made inlays (LMI were used for buccal cavities, and CAD/CAM inlays (CMI were used for lingual cavities. All the cavities were divided into six groups (n=10: 1 LMI at -5°C; 2 LMI at 50°C; 3 LMI at room temperature (25°C; 4 CMI at -5°C; 5 CMI at 50°C; 6 CMI at room temperature (25°C. Inlays were bonded to cavities in a pulp pressure- and temperaturesimulating device. After thermocycling and dye penetration, the teeth were divided into two mesiodistal halves. Amount of dye penetration and film thickness were measured under a stereomicroscope and analyzed with Kruskal-Wallis, Wilcoxon and Spearman's correlation tests ( = 0.05. Results. There were no statistically significant differences in leakage between different inlay temperatures (P > 0.05. The mean cement thickness in laboratory-made inlays (gingival margin, 83.7 ± 11 and occlusal margin, 84.7 ± 19 was greater than that in CAD/CAM inlays (gingival margin, 69 ± 16 and occlusal margin, 84.7 ± 16. No correlation was found between cement thickness and microleakage either in enamel or dentin for any of the ceramic systems. Conclusion. Differences in inlay temperature had no effect on microleakage. CAD/CAM inlays had lower cement thickness than laboratory-made inlays, but this was not related to their microleakage.

  12. Comparison of microleakage and thickness of resin cement in ceramic inlays with various temperatures.

    Science.gov (United States)

    Alaghemand, Homayoun; Abolghasemzadeh, Faezeh; Pakdel, Farzaneh; Judi Chelan, Reza

    2014-01-01

    Background and aims. Microleakage is still one of the major problems of composite-based restorations.This study compared the microleakage and thickness of resin cement in ceramic inlays with various temperatures. Materials and methods. Class V cavities were prepared on the buccal and lingual aspects of thirty human molars with occlusal margins in enamel and gingival margins in dentin (3 mm wide, 5 mm long and 2 mm deep). Laboratory-made inlays (LMI) were used for buccal cavities, and CAD/CAM inlays (CMI) were used for lingual cavities. All the cavities were divided into six groups (n=10): 1) LMI at -5°C; 2) LMI at 50°C; 3) LMI at room temperature (25°C); 4) CMI at -5°C; 5) CMI at 50°C; 6) CMI at room temperature (25°C). Inlays were bonded to cavities in a pulp pressure- and temperature-simulating device. After thermocycling and dye penetration, the teeth were divided into two mesiodistal halves. Amount of dye penetration and film thickness were measured under a stereomicroscope and analyzed with Kruskal-Wallis, Wilcoxon and Spearman's correlation tests ( = 0.05). Results. There were no statistically significant differences in leakage between different inlay temperatures (P > 0.05). The mean cement thickness in laboratory-made inlays (gingival margin, 83.7 ± 11 and occlusal margin, 84.7 ± 19) was greater than that in CAD/CAM inlays (gingival margin, 69 ± 16 and occlusal margin, 84.7 ± 16). No correlation was found be-tween cement thickness and microleakage either in enamel or dentin for any of the ceramic systems. Conclusion. Differences in inlay temperature had no effect on microleakage. CAD/CAM inlays had lower cement thickness than laboratory-made inlays, but this was not related to their microleakage.

  13. Comparison of the Structural Performance of Monolithic and Precast Reinforced Concrete Core Walls

    OpenAIRE

    Nakachi, Tadaharu

    2014-01-01

    In the core wall system in high-rise buildings, the four L-shaped core walls at the center effectively reduce seismic vibration. On the other hand, precast core walls are effective for construction because they can be built more quickly than cast-in-place core walls. In this study, a lateral loading test was conducted on a monolithic wall column simulating the corner and the area near the corner of an L-shaped core wall. The test results were compared with those of a precast wall column teste...

  14. Economical Thermal Insulation Thickness on External Wall of Teaching Building in a University in Tianjin%天津地区某高校教学楼外墙保温层经济性厚度研究

    Institute of Scientific and Technical Information of China (English)

    周淑玲; 高辉

    2014-01-01

    以天津地区某高校教学楼为例,用Designbuilder7.2模拟分析其建筑外墙采用XPS挤塑聚苯板为保温层时的制冷及采暖的耗能量,分析保温层厚度与建筑能耗之间的变化关系;再基于生命周期成本分析法原理,建立材料费用、能耗费用以及保温层厚度之间的数学模型,得出该高校教学楼外墙保温层的经济性厚度,对保温层厚度计算方法的研究及寒冷地区外墙保温层的经济性厚度的选择均具有一定的意义。%Taking a university in Tianjin as an example, the cooling and heating energy consumption of building with external wall taking XPS as insulation layer is simulated with Designbuilder7.2 to study the relationship between thermal insulation thickness and energy consumption, to conclude the economical thickness of thermal insulation on external wall. The economical thermal insulation thickness on external wall is concluded by establishing mathematical model of material cost, energy cost and insulation thickness. The calculation for thermal insulation thickness and the selection of economical thermal insulation thick-ness on external wall in cold area are expounded.

  15. Crustal Thickness Across Alaska via Ps Receiver Functions and Gravity Data and Comparison to Lithospheric Structure

    Science.gov (United States)

    O'Driscoll, L.; Saltus, R. W.; Miller, M. S.; Porritt, R. W.

    2015-12-01

    The geologic mosaic of terranes, adjacent multi-phase plate boundary, rapid lateral topographic variations, and heterogeneous distribution of strain throughout Alaska all suggest strong heterogeneity of crustal architecture. We present a model of crustal thickness across the state is primarily constrained where seismic instrumentation has been deployed - dense coverage in the south-central region and sparse coverage in the north, west, and arc regions. P receiver functions (PRF) were calculated using an upgraded version of Funclab, a software module that retrieves data, calculates receiver functions, facilitates quality control, and calculates H-k stacking, depth mapping via binned Common Conversion Point stacking, and other backend products. 1,678 events and 262 stations yielded 102,000 preliminary PRF that were culled to 21,000 total RFs. Iterative time-domain deconvolution was performed about a 1 Hz central frequency for ZRT traces. Our model reproduces many of the Moho depth variations previously modeled by receiver functions and gravity. Thick (>60 km) crust below the Chugach and St. Elias Ranges transitions to ~40 km thick crust south of the Denali Fault. Immediately to the north, thin (29-35) crust is observed in central Alaska between the Alaska and Brooks Ranges. The central Brooks Range is observed to have a thick crustal root below its topographic high axis. Stations scattered throughout western Alaska and the Bering Sea regions generally show average (~35 km) thickness crust while displaying inter-station uniqueness in the form of stacked RFs. Below the forearc and central Alaska Range, the Yakutat slab Moho is also observed. To complete coverage for the state we use a gravity Moho model calibrated to our receiver function solutions. The resolution of gravity-derived Moho models is limited and can only produce a smoothed approximation of the actual Moho. Where receiver function results are dense we observe significant complexity to the Moho, consistent

  16. Comparison of temporalis fascia muscle and full-thickness cartilage grafts in type 1 pediatric tympanoplasties.

    Science.gov (United States)

    Yegin, Yakup; Çelik, Mustafa; Koç, Arzu Karaman; Küfeciler, Levent; Elbistanlı, Mustafa Suphi; Kayhan, Fatma Tülin

    Various graft materials have been used to close tympanic membrane perforations. In the literature, there are few studies in pediatric populations comparing different graft materials. To our knowledge, there is no reported study that measured the thickness of the tragal cartilage in pediatric tympanoplasties. The tragal cartilage is not of uniform thickness in every patient. To compare anatomical and functional outcomes of temporalis fascia muscle and full-thickness tragal cartilage in type 1 pediatric tympanoplasties. In total, 78 patients (38 males, 40 females; average age 10.02±1.98 years; range, 7-18 years) who underwent type 1 tympanoplasties in our clinic were included. Demographics, anatomical, and functional outcomes were collected. Temporalis fascia muscle and tragal cartilage were used as graft materials. Tragal cartilage was used without thinning, and the thickness of tragal cartilage was measured using a micrometer. Anatomical and functional outcomes of cartilage and fascia were compared. Audiometric results comparing the cartilage and fascia groups were conducted at 6 months, and we continued to follow the patients to 1 year after surgery. An intact graft and an air-bone gap≤20dB were regarded as a surgical success. Results with a p-valuefascia group. In the fascia group, the preoperative air-bone gap was 33.68±11.44 dB and postoperative air-bone gap was 24.25±12.68dB. In the cartilage group, the preoperative air-bone gap was 35.68±12.94dB and postoperative air-bone gap was 26.11±12.87dB. The anatomical success rate in the cartilage group was significantly better than that for the fascia group (pfascia and cartilage groups (p>0.05). The average thickness of tragal cartilage in the pediatric population was 0.693±0.094mm in males and 0.687±0.058 mm in females. Our data suggest that the anatomical success rate for a cartilage tympanoplasty was higher than for a fascia tympanoplasty. Functional results with cartilage were not different than with

  17. A comparison of two methods to measure choroidal thickness by enhanced depth imaging optical coherence tomography

    DEFF Research Database (Denmark)

    Lundberg, Lars Kristian; Vestergaard, Anders Højslet; Vergmann, Anna Stage

    coherence tomography (EDI-SD OCT) has made it possible to visualize the choroid, and it is generally accepted that Heidelberg Spectralis OCT provides valid measurements of choroidal thickness (CT), although no fully automated software is commercially available. Two methods for CT-measurement are available...... the CT: 1: Segmentation method; by the use of the thickness profile window we manually edited and moved the inner limiting membrane (ILM) line to the choroid-scleral border (CSB), while we kept the automated defined Bruchs membrane (BM). Hereafter, the software calculated the vertical distance between......Introduction The choroid is believed to be involved in the pathophysiology of several vision threatening diseases such as age-related macular degeneration, central serous chorioretinopathy, inflammatory disorders and myopic macular degeneration. Enhanced depth imaging spectral-domain optical...

  18. Comparison and Validation of Four Arctic Sea Ice Thickness Products of the EC POLAR ICE Project

    Science.gov (United States)

    Melsheimer, C.; Makynen, M.; Rasmussen, T. S.; Rudjord, Ø.; Simila, M.; Solberg, R.; Walker, N. P.

    2016-08-01

    Sea ice thickness (SIT) is an important parameter for monitoring Arctic change, modelling and predicting weather and climate, and for navigation and offshore operations. However, SIT is still not very well monitored operationally. In the European Commission (EC) FP7 project "POLAR ICE", three novel SIT products based on different satellite data as well as SIT from a state-of-the- art ocean and sea ice model are fed into a common data handling and distribution system for end users. Each SIT product has different scopes and limitations as to, e.g., spatial and temporal resolution, ice thickness range and geographical domain. The aim of this study is to compare the four different SIT products with each other and with SIT in-situ measurements in order to better understand the differences and limitations, and possibly give recommendations on how to best profit from the synergy of the different data.

  19. Experimental Comparison of the Behavior between Base Oil and Grease Starvation Based on Inlet Film Thickness

    Directory of Open Access Journals (Sweden)

    D. Kostal

    2017-03-01

    Full Text Available This paper deals with the experimental study of an elastohydrodynamic contact under conditions of insufficient lubricant supply. Starvation level of this type of the contact may be experimentally determined based on the position of the meniscus, but this way can't determine all levels of starvation. Consequent development in the field of tribology achieved theoretical model that can determine all levels of starvation by dependency on the thickness of the lubricant film entering the contact, but it is difficult for experimental verification. The main goal of this work is an experimental study and description of the behavior of the elastohydrodynamic contact with controlled thickness of the lubricant film at the contact input. Contact was lubricated by the base oil and the grease and compared. Results were surprising because the only differences between oil and grease were observed for more viscous lubricants at thicker film layer entering to the contact.

  20. Comparison of SRIM, MCNPX and GEANT simulations with experimental data for thick Al absorbers.

    Science.gov (United States)

    Evseev, Ivan G; Schelin, Hugo R; Paschuk, Sergei A; Milhoretto, Edney; Setti, João A P; Yevseyeva, Olga; de Assis, Joaquim T; Hormaza, Joel M; Díaz, Katherin S; Lopes, Ricardo T

    2010-01-01

    Proton computerized tomography deals with relatively thick targets like the human head or trunk. In this case precise analytical calculation of the proton final energy is a rather complicated task, thus the Monte Carlo simulation stands out as a solution. We used the GEANT4.8.2 code to calculate the proton final energy spectra after passing a thick Al absorber and compared it with the same conditions of the experimental data. The ICRU49, Ziegler85 and Ziegler2000 models from the low energy extension pack were used. The results were also compared with the SRIM2008 and MCNPX2.4 simulations, and with solutions of the Boltzmann transport equation in the Fokker-Planck approximation.

  1. On the comparison between MRI and US imaging for human heel pad thickness measurements

    DEFF Research Database (Denmark)

    Matteoli, Sara; Corbin, Nadège Corbin; Wilhjelm, Jens E.;

    2011-01-01

    The human heel pad thickness, defined as the shortest distance between the calcaneus and heel skin, is one of the intrinsic factor which must be taken into account when investigating the biomechanics of the heel pad. US and MRI are the preferable imaging modalities used to measure the heel pad...... thickness as they are both ionizing-free radiations. The aim of this paper is to measure the bone to skin distance of nine heel pad phantoms from MRI and US images, and to compare the results with a true value (TV) in order to find the errors. Paired sample t-test was used to compare the measurements......1530 (P-value=0.402). Results confirm the necessity to investigate on the real speed of sound for the heel pad tissues, in order to have realistic measurements when dealing with human heel pads. __________________________________________________________________________________________________________...

  2. MR fetography using heavily T2-weighted sequences: Comparison of thin- and thick-slab acquisitions

    Energy Technology Data Exchange (ETDEWEB)

    Huisman, Thierry A.G.M. [Department of Diagnostic Imaging, University Children' s Hospital Zurich (Switzerland); Division Pediatric Radiology, Johns Hopkins Hospital, Baltimore (United States)], E-mail: thuisma1@jhmi.edu; Solopova, Alina [Department of Diagnostic Imaging, University Children' s Hospital Zurich (Switzerland)

    2009-09-15

    Purpose: To evaluate the use of MR-fetography sequences in identifying the major fetal structures and to compare thick- and thin-slab acquisitions for their diagnostic value. Materials and methods: Twenty-one consecutive, pregnant women with suspected fetal pathology underwent fetal magnetic resonance imaging (MRI) using a 1.5 T MRI unit. Heavily T2-weighted, single-shot fast spin-echo (SSFSE) sequences with a long echo train (MR-fetography) were acquired in a thick- and thin-slab modus. Thick- and thin-slab acquisitions were reviewed by two experienced radiologists with regard to the overall image quality and landmark anatomical structures (spinal canal, spinal cord, posterior fossa, cerebellum, brainstem, basal cisterns, stomach, urinary bladder and umbilical cord according to a three-scale grading system (good, moderate and poor). Visibility scores were calculated and compared between both sequences. Results: Overall image quality was graded good in 76.2%, moderate in 19.0% and poor in 4.8% for thick-slab images and good in 81%, moderate in 14.3% and poor in 4.8% for thin-slab images. The visibility scores of the thick/thin-slab images for evaluation of the main fetal structures were as follows: for the spinal canal 2.8 {+-} 0.4/2.9 {+-} 0.54 (p > 0.05), spinal cord 2.4 {+-} 0.75/2.7 {+-} 0.66 (p > 0.05), posterior fossa components (cerebellum, brainstem and basal cisterns) 2.4 {+-} 0.68/2.8 {+-} 0.54; 2.4 {+-} 0.67/2.7 {+-} 0.66; 2.5 {+-} 0.51/2.7 {+-} 0.56 (p < 0.05), stomach 2.8 {+-} 0.44/2.9 {+-} 0.48 (p > 0.05), urinary bladder 2.8 {+-} 0.51/2.8 {+-} 0.54 (p > 0.05) and umbilical cord 2.9 {+-} 0.30/2.6 {+-} 0.60 (p < 0.05). Conclusion: Heavily T2-weighted MR-fetography renders a quick overview of fetal contours, fetal position, amount of amniotic fluid and integrity and presence of several major fluid containing structures. Thick- and thin-slab acquisitions render complementary information. Thick-slab images display the entire fetus in one projection while

  3. Nonlinear transient heat transfer and thermoelastic analysis of thick-walled FGM cylinder with temperature-dependent material properties using Hermitian transfinite element

    Energy Technology Data Exchange (ETDEWEB)

    Azadi, Mohammad [Sharif University of Technology, Tehran (Iran, Islamic Republic of); Azadi, Mahboobeh [Shiraz University, Shiraz (Iran, Islamic Republic of)

    2009-10-15

    Nonlinear transient heat transfer and thermoelastic stress analyses of a thick-walled FGM cylinder with temperature dependent materials are performed by using the Hermitian transfinite element method. Temperature-dependency of the material properties has not been taken into account in transient thermoelastic analysis, so far. Due to the mentioned dependency, the resulting governing FEM equations of transient heat transfer are highly nonlinear. Furthermore, in all finite element analysis performed so far in the field, Lagrangian elements have been used. To avoid an artificial local heat source at the mutual boundaries of the elements, Hermitian elements are used instead in the present research. Another novelty of the present paper is simultaneous use of the transfinite element method and updating technique. Time variations of the temperature, displacements, and stresses are obtained through a numerical Laplace inversion. Finally, results obtained considering the temperature-dependency of the material properties are compared with those derived based on temperature independency assumption. Furthermore, the temperature distribution and the radial and circumferential stresses are investigated versus time, geometrical parameters and index of power law. Results reveal that the temperature-dependency effect is significant

  4. Using Fourier and Taylor series expansion in semi-analytical deformation analysis of thick-walled isotropic and wound composite structures

    Directory of Open Access Journals (Sweden)

    Jiran L.

    2016-06-01

    Full Text Available Thick-walled tubes made from isotropic and anisotropic materials are subjected to an internal pressure while the semi-analytical method is employed to investigate their elastic deformations. The contribution and novelty of this method is that it works universally for different loads, different boundary conditions, and different geometry of analyzed structures. Moreover, even when composite material is considered, the method requires no simplistic assumptions. The method uses a curvilinear tensor calculus and it works with the analytical expression of the total potential energy while the unknown displacement functions are approximated by using appropriate series expansion. Fourier and Taylor series expansion are involved into analysis in which they are tested and compared. The main potential of the proposed method is in analyses of wound composite structures when a simple description of the geometry is made in a curvilinear coordinate system while material properties are described in their inherent Cartesian coordinate system. Validations of the introduced semi-analytical method are performed by comparing results with those obtained from three-dimensional finite element analysis (FEA. Calculations with Fourier series expansion show noticeable disagreement with results from the finite element model because Fourier series expansion is not able to capture the course of radial deformation. Therefore, it can be used only for rough estimations of a shape after deformation. On the other hand, the semi-analytical method with Fourier Taylor series expansion works very well for both types of material. Its predictions of deformations are reliable and widely exploitable.

  5. Hypertensive heart disease versus hypertrophic cardiomyopathy: multi-parametric cardiovascular magnetic resonance discriminators when end-diastolic wall thickness ≥ 15 mm.

    Science.gov (United States)

    Rodrigues, Jonathan C L; Rohan, Stephen; Ghosh Dastidar, Amardeep; Harries, Iwan; Lawton, Christopher B; Ratcliffe, Laura E; Burchell, Amy E; Hart, Emma C; Hamilton, Mark C K; Paton, Julian F R; Nightingale, Angus K; Manghat, Nathan E

    2017-03-01

    European guidelines state left ventricular (LV) end-diastolic wall thickness (EDWT) ≥15mm suggests hypertrophic cardiomyopathy (HCM), but distinguishing from hypertensive heart disease (HHD) is challenging. We identify cardiovascular magnetic resonance (CMR) predictors of HHD over HCM when EDWT ≥15mm. 2481 consecutive clinical CMRs between 2014 and 2015 were reviewed. 464 segments from 29 HCM subjects with EDWT ≥15mm but without other cardiac abnormality, hypertension or renal impairment were analyzed. 432 segments from 27 HHD subjects with EDWT ≥15mm but without concomitant cardiac pathology were analyzed. Magnitude and location of maximal EDWT, presence of late gadolinium enhancement (LGE), LV asymmetry (>1.5-fold opposing segment) and systolic anterior motion of the mitral valve (SAM) were measured. Multivariate logistic regression was performed. Significance was defined as pheart disease (HHD) can be difficult to distinguish from HCM. • Retrospective case-control study showed that location and magnitude of EDWT are poor discriminators. • Increased left ventricular mass and midwall fibrosis are independent predictors of HHD. • Cardiovascular magnetic resonance parameters facilitate a better discrimination between HHD and HCM.

  6. Thickness of the Meniscal Lamellar Layer: Correlation with Indentation Stiffness and Comparison of Normal and Abnormally Thick Layers by Using Multiparametric Ultrashort Echo Time MR Imaging.

    Science.gov (United States)

    Choi, Ja-Young; Biswas, Reni; Bae, Won C; Healey, Robert; Im, Michael; Statum, Sheronda; Chang, Eric Y; Du, Jiang; Bydder, Graeme M; D'Lima, Darryl; Chung, Christine B

    2016-07-01

    Purpose To determine the relationship between lamellar layer thickness on ultrashort echo time (UTE) magnetic resonance (MR) images and indentation stiffness of human menisci and to compare quantitative MR imaging values between two groups with normal and abnormally thick lamellar layers. Materials and Methods This was a HIPAA-compliant, institutional review board-approved study. Nine meniscal pieces were obtained from seven donors without gross meniscal pathologic results (mean age, 57.4 years ± 14.5 [standard deviation]). UTE MR imaging and T2, UTE T2*, and UTE T1ρ mapping were performed. The presence of abnormal lamellar layer thickening was determined and thicknesses were measured. Indentation testing was performed. Correlation between the thickness and indentation stiffness was assessed, and mean quantitative MR imaging values were compared between the groups. Results Thirteen normal lamellar layers had mean thickness of 232 μm ± 85 and indentation peak force of 1.37 g ± 0.87. Four abnormally thick lamellar layers showed mean thickness of 353.14 μm ± 98.36 and peak force 0.72 g ± 0.31. In most cases, normal thicknesses showed highly positive correlation with the indentation peak force (r = 0.493-0.912; P thickness in two abnormal lamellar layers showed highly negative correlation (r = -0.90, P thick lamellar layers were increased compared with values in normal lamellar layers, although only the UTE T2* value showed significant difference (P = .010). Conclusion Variation of lamellar layer thickness in normal human menisci was evident on two-dimensional UTE images. In normal lamellar layers, thickness is highly and positively correlated with surface indentation stiffness. UTE T2* values may be used to differentiate between normal and abnormally thickened lamellar layers. (©) RSNA, 2016.

  7. Myocardial wall-thickness transducer

    Science.gov (United States)

    Feldstein, C.; Lewis, G. W.; Silver, R. H.; Culler, V. H.

    1976-01-01

    Device consists of highly compliant circular beam attached to piezoresistive strain gage and barbed needle. Radial deflection of myocardium is measured with minimal disturbance of normal heart functions.

  8. Comparison of 4-chloro-2-nitrophenol adsorption on single-walled and multi-walled carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Mehrizad Ali

    2012-09-01

    Full Text Available Abstract The adsorption characteristics of 4-chloro-2-nitrophenol (4C2NP onto single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs from aqueous solution were investigated with respect to the changes in the contact time, pH of solution, carbon nanotubes dosage and initial 4C2NP concentration. Experimental results showed that the adsorption efficiency of 4C2NP by carbon nanotubes (both of SWCNTs and MWCNTs increased with increasing the initial 4C2NP concentration. The maximum adsorption took place in the pH range of 2–6. The linear correlation coefficients of different isotherm models were obtained. Results revealed that the Langmuir isotherm fitted the experimental data better than the others and based on the Langmuir model equation, maximum adsorption capacity of 4C2NP onto SWCNTs and MWCNTs were 1.44 and 4.42 mg/g, respectively. The observed changes in the standard Gibbs free energy, standard enthalpy and standard entropy showed that the adsorption of 4C2NP onto SWCNTs and MWCNTs is spontaneous and exothermic in the temperature range of 298–328 K.

  9. Comparison of 4-Chloro-2-Nitrophenol Adsorption on Single-Walled and Multi-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Karim Zare

    2012-09-01

    Full Text Available The adsorption characteristics of 4-chloro-2-nitrophenol (4C2NP onto single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs from aqueous solution were investigated with respect to the changes in the contact time, pH of solution, carbon nanotubes dosage and initial 4C2NP concentration. Experimental results showed that the adsorption efficiency of 4C2NP by carbon nanotubes (both of SWCNTs and MWCNTs increased with increasing the initial 4C2NP concentration. The maximum adsorption took place in the pH range of 2–6. The linear correlation coefficients of different isotherm models were obtained. Results revealed that the Langmuir isotherm fitted the experimental data better than the others and based on the Langmuir model equation,maximum adsorption capacity of 4C2NP onto SWCNTs and MWCNTs were 1.44 and 4.42 mg/g, respectively. Theobserved changes in the standard Gibbs free energy, standard enthalpy and standard entropy showed that the adsorption of 4C2NP onto SWCNTs and MWCNTs is spontaneous and exothermic in the temperature range of 298–328 K.

  10. Comparison of gold leaf thickness in Namban folding screens using X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Pessanha, Sofia; Madeira, Teresa I.; Manso, Marta [Centro de Fisica Atomica da Universidade de Lisboa, Lisbon (Portugal); Guerra, Mauro; Carvalho, Maria Luisa [Centro de Fisica Atomica da Universidade de Lisboa, Lisbon (Portugal); Universidade Nova de Lisboa, Departamento de Fisica, Faculdade de Ciencias e Tecnologia, Caparica (Portugal); Gac, Agnes le [Centro de Fisica Atomica da Universidade de Lisboa, Lisbon (Portugal); Universidade Nova de Lisboa, Departamento de Conservacao e Restauro, Faculdade de Ciencias e Tecnologia, Caparica (Portugal)

    2014-09-15

    In this work, the thickness of the gold leaf applied in six Japanese folding screens is compared using a nondestructive approach. Four screens belonging to the Momoyama period (∝1573-1603) and two screens belonging to the early Edo period (∝1603-1868) were analyzed in situ using energy dispersive X-ray fluorescence, and the thickness of the applied gold leaf was evaluated using a methodology based on the attenuation of the different characteristic lines of gold in the gold leaf layer. Considering that the leaf may well not be made of pure gold, we established that, for the purpose of comparing the intensity ratios of the Au lines, layers made with gold leaf of high grade can be considered identical. The gold leaf applied in one of the screens from the Edo period was found to be thinner than the gold leaf applied in the other ones. This is consistent with the development of the beating technology to obtain ever more thin gold leafs. (orig.)

  11. Measurement of neutron attenuation through thick shields and comparison with calculation

    Energy Technology Data Exchange (ETDEWEB)

    Bull, J.S.; Donahue, J.B.; Burman, R.L.

    1998-12-31

    The large neutrino experiments conducted over the last several years at the Los Alamos Neutron Science Center (LANSCE) have provided the opportunity to measure the effects of neutron attenuation in very thick shields. These experiments have featured detectors with active masses of 6 to 150 tons and shield thicknesses ranging from 3000 to 5280 g/cm{sup 2}. An absolute measurement of the high-energy neutron flux was made from the beam stop in a neutrino cave at ninety degrees and nine meters from the beam stop. Differential neutron shielding measurements in iron were also performed, resulting in an attenuation length of 148 g/cm{sup 2}. These measurements allow for the testing of radiation shielding codes for deep penetration problems. The measured flux and attenuation length is compared to calculations using the LAHET Code System (LCS). These codes incorporate biasing techniques, allowing for direct calculation of deep penetration shielding problems. Calculations of the neutron current and attenuation length are presented and compared with measured values. Results from the shielding codes show good agreement with the measured values.

  12. Estimation of body fat in Pakistani adult: A comparison of equations based upon skinfold thickness measurements.

    Science.gov (United States)

    Naz, Hafeeza; Mushtaq, Kinza; Butt, Bilal Azeem; Khawaja, Khadija Irfan

    2017-01-01

    To compare three different body fats estimation equations using skin fold measurements with bioelectrical impedance analysis. A total of 130 subjects were included from Department of Endocrinology and Metabolism, Services Hospital, Lahore from 1(st) April 2016 to 30(th) Sep. 2016. The triceps, biceps, subscapular, chest, thigh, abdominal, suprailiac skinfold thickness of the subjects was measured with skin-fold calipers (Harpenden) on non-dominant side. The percentage fat mass (%FM) predicted by using each skin-fold-thickness equations namely Durnin & Womersley, Jackson & Pollock and Sloan was compared with %FM measured using a bioelectrical impedance analyzer (BIA). The mean age of subjects was 48.75±10.7 years, mean BMI was 29.08±6.09 kg/m(2). The mean %FM calculated by Durnin & Womersley (32.408±0.584), Jackson & Pollock (24.658±0.527), Sloan (20.40±0.545). The %FM by BIA was 38.182±0.529. All three equations showed positive correlation but underestimated %FM as compared to BIA. All three BF estimation equations underestimate body fat percentage compared to BIA. Among the three, Durnin & Womersley equation shows best positive correlation and hence it can be used for estimation of percentage fat mass as an alternate to BIA.

  13. A surface based approach for cortical thickness comparison between PiB+ and PiB- healthy control subjects

    Science.gov (United States)

    Doré, Vincent; Bourgeat, Pierrick; Fripp, Jurgen; Acosta, Oscar; Chetelat, Gael; Szoeke, Cassandra; Ellis, Kathryn A.; Martins, Ralph N.; Villemagne, Victor; Masters, Colin L.; Ames, David; Rowe, Christopher C.; Salvado, Olivier

    2012-02-01

    β-amyloid has been shown to play a crucial role in Alzheimer's disease (AD). In vivo β-amyloid imaging using [11C]Pittsburgh compound Β (PiB) positron emission tomography has made it possible to analyze the relationship between β-amyloid deposition and different pathological markers involved in AD. PiB allows us to stratify the population between subjects which are likely to have prodromal AD, and those who don't. The comparison of the cortical thickness in these different groups is important to better understanding and detect the first symptoms of the disease which may lead to an earlier therapeutic care to reduce neurone loss. Several techniques have been developed to compare the cortical volume and/or thickness between AD and HC groups. However due to the noise introduced by the cortical thickness estimation and by the registration, these methods do not allow to unveil any major different when comparing prodromal AD groups with healthy control subjects group. To improve our understanding of where initial Alzheimer neurodegeneration occurs in the cortex we have developed a surface based technique, and have applied it to the discrimination between PIB-positive and PiB-negative HCs. We first identify the regions where AD patients show high cortical atrophy by using an AD/PiB- HC vertex-wise T-test. In each of these discriminating regions, comparison between PiB+ HC, PiB- HC and AD are performed. We found some significant differences between the two HC groups in the hippocampus and in the temporal lobe for both hemisphere and in the precuneus and occipital regions only for the left hemisphere.

  14. Comparison of aerosol optical thickness retrieval from spectroradiometer measurements and from two radiative transfer models

    Energy Technology Data Exchange (ETDEWEB)

    Utrillas, M.P.; Martinez-Lozano, J.A.; Tena, F. [Universitat de Valencia, Dept. de Termodinamica, Valencia (Spain); Cachorro, V.E. [Universidad de Valladolid, Dept. de Fisica Aplicada 1, Valladolid (Spain); Hernandez, S. [Universidad de Valladolid, Dept. de Ingenieria Agricola y Forestal, Valladolid (Spain)

    2000-07-01

    The spectral values of the aerosol optical thickness {tau}{sub a{lambda}} in the 400-670 nm band have been determined from 500 solar direct irradiance spectra at normal incidence registered at Valencia (Spain) in the period from July 1993 to March 1997. The {tau}{sub a{lambda}} values obtained from experimental measurements have been compared with the boundary layer aerosol models implemented in the radiative transfer codes ZD-LOA and LOWTRAN 7. For the ZD-LOA code, the continental and maritime models have been considered and for the LOWTRAN 7 code the rural, maritime, urban and tropospheric models have been used. The obtained results show that the aerosol model that best represents the average turbidity of the boundary layer for the urban area of Valencia (Spain) is the continental model when the ZD-LOA code is used and the urban model when the LOWTRAN 7 code is used. (Author)

  15. Cortical Thickness in Dementia with Lewy Bodies and Alzheimer's Disease: A Comparison of Prodromal and Dementia Stages.

    Directory of Open Access Journals (Sweden)

    Frederic Blanc

    Full Text Available To assess and compare cortical thickness (CTh of patients with prodromal Dementia with Lewy bodies (pro-DLB, prodromal Alzheimer's disease (pro-AD, DLB dementia (DLB-d, AD dementia (AD-d and normal ageing.Study participants(28 pro-DLB, 27 pro-AD, 31 DLB-d, 54 AD-d and 33 elderly controls underwent 3Tesla T1 3D MRI and detailed clinical and cognitive assessments. We used FreeSurfer analysis package to measure CTh and investigate patterns of cortical thinning across groups.Comparison of CTh between pro-DLB and pro-AD (p<0.05, FDR corrected showed more right anterior insula thinning in pro-DLB, and more bilateral parietal lobe and left parahippocampal gyri thinning in pro-AD. Comparison of prodromal patients to healthy elderly controls showed the involvement of the same regions. In DLB-d (p<0.05, FDR corrected cortical thinning was found predominantly in the right temporo-parietal junction, and insula, cingulate, orbitofrontal and lateral occipital cortices. In AD-d(p<0.05, FDR corrected,the most significant areas affected included the entorhinal cortices, parahippocampal gyri and parietal lobes. The comparison of AD-d and DLB-d demonstrated more CTh in AD-d in the left entorhinal cortex (p<0.05, FDR corrected.Cortical thickness is a sensitive measure for characterising patterns of grey matter atrophy in early stages of DLB distinct from AD. Right anterior insula involvement may be a key region at the prodromal stage of DLB and needs further investigation.

  16. Comparison of Central Macular Thickness Measured by Three OCT Models and Study of Interoperator Variability

    Directory of Open Access Journals (Sweden)

    Zaïnab Bentaleb-Machkour

    2012-01-01

    Full Text Available Purpose. To compare central macular thickness (CMT measurement on healthy patient using 3 different OCT devices by two operators. Methods. Prospective, monocentricstudy. Right eye’s central macular thickness (CMT of 30 healthy patients has been measured three times using a time-domain (TD OCT (Stratus OCT, Carl Zeiss Meditec, Dublin, Ca and two spectral domain (SD OCTs (Cirrus HD-OCT, Carl ZeissMeditec, Dublin, Ca and 3D-OCT 1000 (Topcon, Tokyo, Japan by two operators. Six measurements were taken randomly for each patient the same day. Results. No significant difference between measurements obtained by the two operators has been observed, whatever the studied OCT. P value was 0.164, 0.193, and 0.147 for Stratus OCT, Cirrus HD-OCT and 3D-OCT, respectively. Mean CMT significantly differed from instrument to instrument (P<0.001 and was, respectively, 197 μm, 254 μm, and 236 μm using Stratus OCT, Cirrus HD-OCT, and 3D-OCT 1000. Using Cirrus OCT and 3D-OCT 1000, CMT was, respectively, 57 μm and 39 μm thicker than using Stratus OCT (P<0.05. Conclusions. Whatever the OCT device, on healthy patients CMT was not operator dependent. CMT measurements obtained by SD-OCTs are greater than those obtained by TD-OCT. These data imply that the different OCT devices cannot be used interchangeably in clinical monitoring.

  17. Comparison between cryopreserved and glycerol-preserved allografts in a partial-thickness porcine wound model.

    Science.gov (United States)

    Yoon, Cheonjae; Lim, Kihwan; Lee, Sungjun; Choi, Yanghwan; Choi, Youngwhan; Lee, Jungsuk

    2016-03-01

    Human skin allografts are one of the best temporary biological coverings for severely burned patients. Cryopreserved (CPA) and glycerol-preserved (GPA) allografts are the most widely used types. This study compared the allograft efficiency of both preservation methods under the same conditions. To simulate actual clinical conditions, we used a porcine wound model. In addition, we evaluated the macroscopic and microscopic scoring of graft performance for each method. Porcine cadaver skin 1 mm thick was obtained from one pig. Cryopreserved skin cell viability was 20.8 %, glycerol-preserved skin was 9.08 %, and fresh skin was 58.6 %. We made ten partial-thickness wounds each in two pigs. The take rates on day 2 were 96.23 and 82.65 % in the GPA and CPA group (both n = 9), respectively. After 1 week, the take rates of both groups were nearly equal. The removal rate at week 5 was 98.87 and 94.41 % in the GPA and CPA group, respectively. On microscopic findings at week 2, inflammation was greater in the CPA group. Other findings such as fibroblast hyperplasia and neovascularization were not significantly different between both groups. At week 5, the score of collagen fiber synthesis was 2.67 ± 0.47 and 2.33 ± 0.47 in the GPA and CPA group, respectively. The epidermal-dermal junction was 2.22 ± 0.79 and 2.00 ± 0.47 in the GPA and CPA group, respectively. These findings suggest that wound healing takes longer in the CPA group. The preservation method of allografts is not a absolute factor in the wound healing process in this wound model.

  18. Drought-induced increase in water-use efficiency reduces secondary tree growth and tracheid wall thickness in a Mediterranean conifer.

    Science.gov (United States)

    Olano, José Miguel; Linares, Juan Carlos; García-Cervigón, Ana I; Arzac, Alberto; Delgado, Antonio; Rozas, Vicente

    2014-09-01

    In order to understand the impact of drought and intrinsic water-use efficiency (iWUE) on tree growth, we evaluated the relative importance of direct and indirect effects of water availability on secondary growth and xylem anatomy of Juniperus thurifera, a Mediterranean anisohydric conifer. Dendrochronological techniques, quantitative xylem anatomy, and (13)C/(12)C isotopic ratio were combined to develop standardized chronologies for iWUE, BAI (basal area increment), and anatomical variables on a 40-year-long annually resolved series for 20 trees. We tested the relationship between iWUE and secondary growth at short-term (annual) and long-term (decadal) temporal scales to evaluate whether gains in iWUE may lead to increases in secondary growth. We obtained a positive long-term correlation between iWUE and BAI, simultaneously with a negative short-term correlation between them. Furthermore, BAI and iWUE were correlated with anatomical traits related to carbon sink or storage (tracheid wall thickness and ray parenchyma amount), but no significant correlation with conductive traits (tracheid lumen) was found. Water availability during the growing season significantly modulated tree growth at the xylem level, where growth rates and wood anatomical traits were affected by June precipitation. Our results are consistent with a drought-induced limitation of tree growth response to rising CO2, despite the trend of rising iWUE being maintained. We also remark the usefulness of exploring this relationship at different temporal scales to fully understand the actual links between iWUE and secondary growth dynamics.

  19. Simulation of bending stress variation in long buried thick-walled pipes under the earth’s movement using combined linear dynamics and beam theories

    Directory of Open Access Journals (Sweden)

    Salau Tajudeen A.O.

    2014-01-01

    Full Text Available This study reported a simulation approach to the understanding of the interactions between a buried pipe and the soil system by computing the bending stress variation of harmonically-excited buried pipes. The established principles of linear dynamics theory and simple beam theory were utilised in the analysis of the problem of buried pipe bending stress accumulation and its dynamics. With regards to the parameters that influence the bending stress variations, the most important are the isolation factor, uniform external load, and the corresponding limiting conditions. The simulated mathematical expressions, containing static and dynamic parameters of the buried pipe and earth, were coded in Fortran programming language and applied in the simulation experiment. The results obtained showed that harmonically-excited buried thick-walled pipe became stable and effective when the ratio of the natural frequency of vibration to the forced frequency is greater than 2.0, whenever the damped factor is used as the control parameter for the maximum bending stress. The mirror image of the stress variation produces variation in the location of the maximum bending stress in quantitative terms. The acceptable pipe materials for the simulated cases must have yield strength in bending greater than or equal to 13.95 MPa. The results obtained in this work fill a gap in the literature and will be useful to pipeline engineers and designers, as well as to environmental scientists in initialising and controlling environmental issues and policy formulation concerning the influence of buried pipe on the soil and water in the environment.

  20. Comparison of laser-ablation and hot-wall chemical vapour deposition techniques for nanowire fabrication

    Science.gov (United States)

    Stern, E.; Cheng, G.; Guthrie, S.; Turner-Evans, D.; Broomfield, E.; Lei, B.; Li, C.; Zhang, D.; Zhou, C.; Reed, M. A.

    2006-06-01

    A comparison of the transport properties of populations of single-crystal, In2O3 nanowires (NWs) grown by unassisted hot-wall chemical vapour deposition (CVD) versus NWs grown by laser-ablation-assisted chemical vapour deposition (LA-CVD) is presented. For nominally identical growth conditions across the two systems, NWs fabricated at 850 °C with laser-ablation had significantly higher average mobilities at the 99.9% confidence level, 53.3 ± 5.8 cm2 V-1 s-1 versus 10.2 ± 1.9 cm2 V-1 s-1. It is also observed that increasing growth temperature decreases mobility for LA-CVD NWs. Transmission electron microscopy studies of CVD-fabricated samples indicate the presence of an amorphous In2O3 region surrounding the single-crystal core. Further, low-temperature measurements verify the presence of ionized impurity scattering in low-mobility CVD-grown NWs.

  1. Forming Simulation of Thick AFP Laminates and Comparison with Live CT Imaging

    Science.gov (United States)

    Leutz, Daniel; Vermilyea, Mark; Bel, Sylvain; Hinterhölzl, Roland

    2016-08-01

    Automated fiber placement (AFP) process can be used to manufacture laminates by laying up unidirectional slit tapes along a desired path and placing multiple layers on top of each other. Usually, the slit tapes are placed direct onto the tooling to attain the final part geometry. Alternatively, the laminate can be built up on a planar substrate and can be subsequently formed into the final shape. This kind of processing allows manufacturing highly curved parts, which may not be possible with the direct placement. In the present work a forming simulation of thick AFP laminates is developed to predict the tapes' orientations and delamination as well as transverse tape spread-ups and separations during the forming process. The simulation model is built up through the material characterization experiments. Validation is performed comparing the results of the simulation vs. the experimental forming on two generic geometries. An optical inspection is made on the external layers of the laminates. In a second step, live computer tomography (CT) scans are used to inspect the tapes within an AFP laminate during forming of an L- and a Z-flange. Tapes re-orientation, gaps and tapes widening are observed experimentally and compared to the simulation results. The simulation is capable to predict the tows orientation and provides indicators concerning the tows spread-up and separation.

  2. Comparison of skinfold thickness models with DEXA: impact of visceral adipose tissue.

    Science.gov (United States)

    Pineau, Jean C; Frey, Alain

    2016-05-01

    This study was designed to evaluate the impact of visceral adipose tissue (VAT) measured by magnetic resonance imaging (MRI) at the umbilical level on the accuracy of body fat percentage (BF%) measurement using the skinfold thickness method (SFT) in athletes. Dual-energy X- ray absorptiometry (DEXA) was the reference standard method for BF% measurement. We studied 22 female elite judokas recruited at the French national sports institute (Institut National des Sports et de l'Education Physique, INSEP) via coaches and trainers. Single MRI slices at L4-L5 were used for manual measurements of VAT and subcutaneous adipose tissue (SAT). A Bland and Altman analysis showed a wide 95% confidence interval for the limits of agreement between DEXA and SFT [- 1.7; +7.1], with a systematic bias consisting in BF% underestimation by SFT compared to DEXA. The VAT/SAT ratio correlated significantly (r=0.53, P=0.012) with the BF% difference between DEXA and SFT. We used this result to correct the BF% value provided by SFT for VAT. DXA provided higher %BF values than an SFT-based method. Consequently, the SFT method cannot be used interchangeably with DXA for assessing %BF. However, VAT cannot be measured accurately using anthropometry or DEXA, and MRI is therefore required to use our correction.

  3. Comparison of three different instruments measuring central corneal thickness of keratoconus

    Directory of Open Access Journals (Sweden)

    Xu Pang

    2013-10-01

    Full Text Available AIM: To compare the difference in measurements of central corneal thickness(CCTusing A-scan,corneal specular microscopy and Pentacam in keratoconus. METHODS: Between July 2012 and October 2012, the CCT of 31 patients(55 eyeswere measured by A-scan, corneal specular microscopy and Pentacam. The results were analyzed by F-test and Pearson correlation. RESULTS: The values of CCT measured by A-scan(55 eyes, corneal specular microscopy(45 eyesand Pentacam(52 eyeswere 469.87±57.56, 479.00±42.39, and 487.02±44.64μm, respectively; F-test results showed there were no statistical significant differences between CCT measured by three different instruments(P>0.05. The correlation between the measurements was evaluated using Pearson correlation coefficients. The CCT values by these three instruments were positively related by linear correlation analysis, A-scan and Pentacam measurements(r1=0.758, Pr2=0.949, Pr3=0.685, PCONCLUSION: There is a high correlation between these three instruments. A-scan and Pentacam are more precise than corneal specular microscopy. Pentacam system can measure the CCT easily, accurately and without any invasion. It is more suitable for people with keratoconus to monitor the every point of cornea and for people to do more deep research.

  4. TIG Auto-Welding Technology on Heavy Wall Thickness Large Diameter and Narrow Gap Welded Pipe%厚壁大直径管窄间隙TIG自动焊技术

    Institute of Scientific and Technical Information of China (English)

    张相福

    2011-01-01

    Aiming at the disadvantages of the TIG-SMAW for heavy wall thickness and large diameter welded pipe, the narrow gap impulse TIG auto-welding technology was developed; it solved some design difficulties in TIG welding, such as penetration in weld sidewall, bevel design and etc. Through research on penetration technology in weld sidewall for narrow gap heavy wall thickness welding, the bevel combination for TIG welding was developed. It designed specified range welding parameters for heavy wall thickness welded pipe with the said bevel, and its process was validated in welding practice; it successfully solved process difficulties of narrow gap TIG auto-welding with heavy wall thickness and large diameter, and obtained excellent effect%针对厚壁大径管氩电联合焊的缺点,开发了窄间隙脉冲TIG自动焊工艺,解决了厚壁大直径管窄间隙TIG焊中焊缝侧壁熔透、坡口设计等难点,通过研究厚壁管窄间隙焊接焊缝侧壁熔透技术,开发厚壁大直径管窄间隙TIG焊组合坡口,设计焊接该种坡口厚壁管的特定范围的焊接工艺参数,并在焊接实例中进一步验证了该工艺技术的可靠性,成功解决了厚壁大直径管窄间隙TIG自动焊的工艺难点,并取得了良好的生产效果.

  5. Design and Finite Element Analysis On a Large Pond With Varying Wall Thickness%某变壁厚高大水池的设计与有限元分析

    Institute of Scientific and Technical Information of China (English)

    梁峰; 金福青; 王庆海; 颜伟华; 王茜

    2012-01-01

    The finite analysis on large pond with varying wall thickness is made specifically hereinafter by use of MIDAS/Gen, whose calculation is accurate and totally can meet the need of engineering design. Compared to buttressed pond with constantly same wall thickness, the large pond with varying wall thickness is characterized by much more reasonable structural design. Such a structure can both satisfy process requirements and feature beautiful profile and good economy. The calculation analysis method and conclusion can be used for reference for designers.%详细介绍了运用MIDAS/Gen软件,对变壁厚高大水池进行有限元分析的方法和实例.计算结果精确,完全满足工程设计的需要.变壁厚高大水池相比扶壁式等壁厚水池,结构设计更为合理.这种结构型式既满足工艺要求,又经济美观.本文的计算分析方法和结论可供设计人员参考.

  6. Development of automated welding processes for field fabrication of thick-walled pressure vessels: electron beam method. Seventh quarterly report, April 1-June 30, 1979. [8-in. thick 2 1/4 Cr-1 Mo plate

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.M.

    1979-01-01

    A total of 449 experimental welds have been made to date. Partial penetration welding procedures capable of producing defect-free, 4-inch deep welds have been developed in the horizontal position. The travel speed that can be acceptably used for partial penetration welding of 2 1/4 Cr-1 Mo is larger for 6-inch thick plate than for 8-inch thick plate. Although defect-free welds can be made with soft vacuum conditions, hard vacuum conditions produce the most reliable performance. A procedure for welding an 8-inch thick joint has been developed. A small test plate was welded, radiographed, and cross sectioned and found to be acceptable. A large 8-inch thick test plate was welded and found to contain porosity. Difficulties in uniformly moving this large plate appear to be responsible for the porosity encountered. A mechanical modification to the welding equipment is being made and the large plate will be welded again. 3 figures.

  7. International Consultation on Incontinence-Research Society (ICI-RS) Report on Non-Invasive Urodynamics: The Need of Standardization of Ultrasound Bladder and Detrusor Wall Thickness Measurements to Quantify Bladder Wall Hypertrophy

    NARCIS (Netherlands)

    M. Oelke

    2010-01-01

    Introduction: Ultrasonic measurements of urinary bladders are suitable to quantify bladder wall hypertrophy due to bladder outlet obstruction, detrusor overactivity, or neurogenic bladder dysfunction in adult men or women and in children. Quantification of bladder wall hypertrophy seems to be useful

  8. SCALE/MAVRIC calculation of dose rates measured for a gamma radiation source in a thick-walled transport and storage cask of ductile cast iron with lead inserts

    Science.gov (United States)

    Baumgarten, Werner; Thiele, Holger; Ruprecht, Benjamin; Phlippen, Peter-W.; Schlömer, Luc

    2017-09-01

    Dose rate calculations are important for judging the shielding performance of transport casks for radioactive material. Therefore it is important to have reliable calculation tools. We report on measured and calculated dose rates near a thick-walled transport and storage cask of ductile cast iron with lead inserts and a Co-60 source inside. In a series of experiments the thickness of the inserts was varied, and measured dose rates near the cask were compared with SCALE/MAVRIC 6.1.3 and SCALE/MAVRIC 6.2 calculation results. Deviations from the measurements were found to be higher for increased lead thicknesses. Furthermore, it is shown how the shielding material density, air scattering and accounting for the floor influence the quality of the calculation.

  9. A comparison of modelling techniques for computing wall stress in abdominal aortic aneurysms

    Directory of Open Access Journals (Sweden)

    McGloughlin Timothy M

    2007-10-01

    Full Text Available Abstract Background Aneurysms, in particular abdominal aortic aneurysms (AAA, form a significant portion of cardiovascular related deaths. There is much debate as to the most suitable tool for rupture prediction and interventional surgery of AAAs, and currently maximum diameter is used clinically as the determining factor for surgical intervention. Stress analysis techniques, such as finite element analysis (FEA to compute the wall stress in patient-specific AAAs, have been regarded by some authors to be more clinically important than the use of a "one-size-fits-all" maximum diameter criterion, since some small AAAs have been shown to have higher wall stress than larger AAAs and have been known to rupture. Methods A patient-specific AAA was selected from our AAA database and 3D reconstruction was performed. The AAA was then modelled in this study using three different approaches, namely, AAA(SIMP, AAA(MOD and AAA(COMP, with each model examined using linear and non-linear material properties. All models were analysed using the finite element method for wall stress distributions. Results Wall stress results show marked differences in peak wall stress results between the three methods. Peak wall stress was shown to reduce when more realistic parameters were utilised. It was also noted that wall stress was shown to reduce by 59% when modelled using the most accurate non-linear complex approach, compared to the same model without intraluminal thrombus. Conclusion The results here show that using more realistic parameters affect resulting wall stress. The use of simplified computational modelling methods can lead to inaccurate stress distributions. Care should be taken when examining stress results found using simplified techniques, in particular, if the wall stress results are to have clinical importance.

  10. Comparison of hybrid and baseline ELMy H-mode confinement in JET with the carbon wall

    Science.gov (United States)

    Beurskens, M. N. A.; Frassinetti, L.; Challis, C.; Osborne, T.; Snyder, P. B.; Alper, B.; Angioni, C.; Bourdelle, C.; Buratti, P.; Crisanti, F.; Giovannozzi, E.; Giroud, C.; Groebner, R.; Hobirk, J.; Jenkins, I.; Joffrin, E.; Leyland, M. J.; Lomas, P.; Mantica, P.; McDonald, D.; Nunes, I.; Rimini, F.; Saarelma, S.; Voitsekhovitch, I.; de Vries, P.; Zarzoso, D.; Contributors, JET-EFDA

    2013-01-01

    The confinement in JET baseline type I ELMy H-mode plasmas is compared to that in so-called hybrid H-modes in a database study of 112 plasmas in JET with the carbon fibre composite (CFC) wall. The baseline plasmas typically have βN ˜ 1.5-2, H98 ˜ 1, whereas the hybrid plasmas have βN ˜ 2.5-3, H98 contains both low- (δ ˜ 0.2-0.25) and high-triangularity (δ ˜ 0.4) hybrid and baseline H-mode plasmas from the last JET operational campaigns in the CFC wall from the period 2008-2009. Based on a detailed confinement study of the global as well as the pedestal and core confinement, there is no evidence that the hybrid and baseline plasmas form separate confinement groups; it emerges that the transition between the two scenarios is of a gradual kind rather than demonstrating a bifurcation in the confinement. The elevated confinement enhancement factor H98 in the hybrid plasmas may possibly be explained by the density dependence in the τ98 scaling as n0.41 and the fact that the hybrid plasmas operate at low plasma density compared to the baseline ELMy H-mode plasmas. A separate regression on the confinement data in this study shows a reduction in the density dependence as n0.09±0.08. Furthermore, inclusion of the plasma toroidal rotation in the confinement regression provides a scaling with the toroidal Alfvén Mach number as Mach_A^{0.41+/- 0.07} and again a reduced density dependence as n0.15±0.08. The differences in pedestal confinement can be explained on the basis of linear MHD stability through a coupling of the total and pedestal poloidal pressure and the pedestal performance can be improved through plasma shaping as well as high β operation. This has been confirmed in a comparison with the EPED1 predictive pedestal code which shows a good agreement between the predicted and measured pedestal pressure within 20-30% for a wide range of βN ˜ 1.5-3.5. The core profiles show a strong degree of pressure profile consistency. No beneficial effect of core

  11. Measurement of magnetic domain wall width using energy-filtered Fresnel images.

    Science.gov (United States)

    Lloyd, S J; Loudon, J C; Midgley, P A

    2002-08-01

    Magnetic domain walls in Nd2Fe14B have been examined using a series of energy-filtered Fresnel images in the field emission gun transmission electron microscope (FEGTEM). We describe the changes in the intensity distribution of the convergent wall image as a function of defocus, foil thickness and domain wall width. The effect of tilted domain walls and beam convergence on the fringe pattern is also discussed. A comparison of the experimental intensity profile with that from simulations allows the domain wall width to be determined. Measurement of very narrow walls is made possible only by using a relatively thick foil, which necessitates energy-filtering to allow quantitative comparison with simulations. The magnetic domain wall width in Nd2Fe14B was found to be 3 +/- 2 nm.

  12. Comparison on heat flux deposition between carbon and tungsten wall – Investigations on energy recycling

    Energy Technology Data Exchange (ETDEWEB)

    Bufferand, H., E-mail: hugo.bufferand@cea.fr [CEA, IRFM, 13108 St Paul-Lez-Durance (France); Bucalossi, J.; Ciraolo, G.; Fedorczak, N. [CEA, IRFM, 13108 St Paul-Lez-Durance (France); Genesio, P. [PIIM, CNRS, Aix-Marseille Université, 13397 Marseille (France); Ghendrih, Ph.; Gunn, J. [CEA, IRFM, 13108 St Paul-Lez-Durance (France); Marandet, Y.; Martin, C.; Mellet, N. [PIIM, CNRS, Aix-Marseille Université, 13397 Marseille (France); Serre, E. [M2P2, CNRS, Aix-Marseille Université, 13451 Marseille (France); Tamain, P. [CEA, IRFM, 13108 St Paul-Lez-Durance (France)

    2015-08-15

    The influence of the plasma facing components material on the scrape-off layer plasma is investigated. In particular, the energy recycling is found to be more pronounced for tungsten wall compared with carbon wall. Edge plasma simulations performed with the transport code SOLEDGE2D-EIRENE show that this enhanced energy recycling in the tungsten case leads to an increase of the scrape-off layer temperature. Moreover, the energy recycling depends on the ion angle of incidence with the wall. A PIC code has been used to model the ion acceleration in the magnetic pre-sheath and determine the later angle of incidence. These simulations show that ions mostly impact the wall with rather shallow incident angles leading to a further increase of the energy recycling.

  13. A comparison between thermographic and flow-meter methods for the evaluation of thermal transmittance of different wall constructions

    Science.gov (United States)

    Nardi, I.; Ambrosini, D.; de Rubeis, T.; Sfarra, S.; Perilli, S.; Pasqualoni, G.

    2015-11-01

    One of the key parameters that “meter” the energy performance of the whole structure of buildings is the thermal transmittance. This parameter can be evaluated with a theoretical approach, regulated by standard ISO 6946, once the stratigraphy of the envelope and the properties of the constituent materials are known, or by using a heat flow meter (HFM), following the recommendations provided in standard ISO 9869. Recently, the use of quantitative IR Thermography (IRT) has been proposed by several researchers; this method allows to determine the overall transmittance of an envelope in a short time (especially in comparison with HFM method). However, the theoretical or experimental transmittance, measured on real buildings having walls composed by different materials, can be rather distant from those calculated or measured with different procedures. For this reason, for a correct certification of the thermal performance of a building envelope, it is necessary the availability of experimental procedures for a direct and reliable evaluation of the thermal transmittance, suitable for different walls. Research has found that, especially in historical constructions, faults in the building envelope and the age of the materials can greatly affect the HFM measurements. The aim of this work is to analyze in situ the thermal performance of three different walls which have been selected according to: different materials, different age, and different construction. On each envelope, a comparison between U-values, measured by HFM and IRT, and computed according the standard procedure, has been effected.

  14. Colon wall motility: comparison of novel quantitative semi-automatic measurements using cine MRI

    OpenAIRE

    Hoad, Caroline; Menys, A.; Garsed, Klara; Marciani, Luca; Hamy, Valentin; Murray, Kathryn; Costigan, Carolyn; Atkinson, D.; Major, Giles; Spiller, Robin C; Taylor, S.; Gowland, Penny A.

    2016-01-01

    Background\\ud \\ud Recently, cine magnetic resonance imaging (MRI) has shown promise for visualizing movement of the colonic wall, although assessment of data has been subjective and observer dependent. This study aimed to develop an objective and semi-automatic imaging metric of ascending colonic wall movement, using image registration techniques.\\ud Methods\\ud \\ud Cine balanced turbo field echo MRI images of ascending colonic motility were acquired over 2 min from 23 healthy volunteers (HVs)...

  15. Ultrasonographic analysis of dorsal neck muscles thickness changes induced by isometric contraction of shoulder muscles: A comparison between patients with chronic neck pain and healthy controls.

    Science.gov (United States)

    Karimi, Noureddin; Rezasoltani, Asghar; Rahnama, Leila; Noori-Kochi, Farhang; Jaberzadeh, Shapour

    2016-04-01

    Altered pattern of muscle activity is commonly seen with chronic neck pain (CNP). However, limited investigations have been done on dorsal neck muscles' activity pattern while performing upper limb tasks in patients with CNP. To investigate dorsal neck muscles' thickness changes during isometric contraction of shoulder muscles. Case-control study. This study investigated dorsal neck muscles' thickness changes during isometric contraction of shoulder muscles in 20 healthy participants (mean age 27 ± 4.37) and 17 patients with CNP (mean age 29 ± 5.50). Effects of isometric force of shoulder muscles on dorsal neck muscles' thickness changes were also evaluated. Significant muscle × group interaction was observed for the dorsal neck muscles thickness changes (p = 0.008) indicating different pattern of muscle activity in terms of changes in muscle thickness of two groups. Significant main effects of direction was observed (P = 0.003), with the abduction had the greatest impact on changing the dorsal neck muscles thickness. patients with CNP showed altered pattern of muscle thickness changes in comparison to healthy participants. Isometric abduction of shoulder muscles induced the greatest changes of dorsal neck muscles thickness among other force directions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. A comparison of the turbulent entrainment process in line plumes and wall plumes

    Science.gov (United States)

    Parker, David; Burridge, Henry; Partridge, Jamie; Linden, Paul

    2016-11-01

    Flows driven by sources of buoyancy appear in a large number of geophysical and industrial applications. The process of turbulent entrainment in these flows is key to understanding how they evolve and how one might model them. It has been observed that the entrainment is reduced when a line source of buoyancy is positioned immediately adjacent to a wall. To gain insight into the effect of the wall on the entrainment process we perform simultaneous PIV and LIF on both line plumes, in the absence of any boundary, and when the source is adjacent to a vertical boundary forming a wall plume. The experiments are designed to isolate the effect of the wall by using the same experimental setup and parameters for both flows with the addition of the wall and half the buoyancy flux used in the wall plume case. Of particular interest is the effect the large scale eddies, forming at the edge of the plume and engulfing ambient fluid, have on the entrainment process. By using velocity statistics in a coordinate system based on the instantaneous scalar edge of the plume, a technique we have recently used to analyse similar effects in an axisymmetric plume, the significance of this large scale engulfment will be quantified.

  17. Architectural and morphological assessment of rat abdominal wall muscles: comparison for use as a human model.

    Science.gov (United States)

    Brown, Stephen H M; Banuelos, Karina; Ward, Samuel R; Lieber, Richard L

    2010-09-01

    The abdominal wall is a composite of muscles that are important for the mechanical stability of the spine and pelvis. Tremendous clinical attention is given to these muscles, yet little is known about how they function in isolation or how they interact with one another. Given the morphological, vascular, and innervation complexities associated with these muscles and their proximity to the internal organs, an appropriate animal model is important for understanding their physiological and mechanical significance during function. To determine the extent to which the rat abdominal wall resembles that of human, 10 adult male Sprague-Dawley rats were killed and formalin-fixed for architectural and morphological analyses of the four abdominal wall muscles (rectus abdominis, external oblique, internal oblique, and transversus abdominis). Physiological cross-sectional areas and optimal fascicle lengths demonstrated a pattern that was similar to human abdominal wall muscles. In addition, sarcomere lengths measured in the neutral spine posture were similar to human in their relation to optimal sarcomere length. These data indicate that the force-generating and length change capabilities of these muscles, relative to one another, are similar in rat and human. Finally, the fiber lines of action of each abdominal muscle were similar to human over most of the abdominal wall. The main exception was in the lower abdominal region (inferior to the pelvic crest), where the external oblique becomes aponeurotic in human but continues as muscle fibers into its pelvic insertion in the rat. We conclude that, based on the morphology and architecture of the abdominal wall muscles, the adult male Sprague-Dawley rat is a good candidate for a model representation of human, particularly in the middle and upper abdominal wall regions.

  18. Effect of sedentary behaviour and vigorous physical activity on segment-specific carotid wall thickness and its progression in a healthy population.

    LENUS (Irish Health Repository)

    2010-06-01

    This study investigated whether sedentary behaviour and different activity levels have an independent association with carotid intima-media thickness (IMT) and with the 3-year IMT progression in different carotid segments.

  19. Comparative Research on the Thickness of the Body Wall of the Mandibulal Incisor in the Mongolian and Han%蒙汉族人下颌切牙颈部牙体壁厚度对比研究

    Institute of Scientific and Technical Information of China (English)

    昭日格图; 缪羽; 孙婧

    2011-01-01

    Objective! To compare the difference and to provide anatomic basis for treatment and restoration of mandibular incisor in the Inner Mongolia region through measuring thickness of the body wall of the neck of mandib-ular incisor in the Mongolian and Han. Methods: 512 mandibular incisors were collected from 128 patients of Mongolian and Han. All of teeth were filmed, reconstructed and measured the thickness of the body wall of the labial surface, lingual surface, mesial surface, distal surface of the mandibular incisor by Newtom3G cone beam computed tomography-imaging systems and operating software NNT filming. Meanwhile, we analyzed the data with the processing system of image analysis . Results: The average thicknesses of Mongolian were thicker than Han in the body walls of the labial surface, mesial surface and diatal surface. The difference was obvious statistically significant (P<0. 05). There was no significant difference in the thickness of the body wall of lingual surface. Conclusion: There are difference between the Han and the Mongolian in the thickness of mandibular incisor from the 36 to 45 - year- old.%目的:通过对蒙古族和汉族人的下颌切牙颈部牙体壁厚度进行测量,对比其间的差异,为内蒙古地区下颌切牙牙体治疗和修复治疗提供解剖学依据.方法:筛选蒙古族和汉族128人的下颌切牙512颗,利用Newtom3G锥形束CT-三维头颅成像系统和NNT操作软件进行拍摄、重建并分别测量牙体颈部唇侧、舌侧、近中、远中牙体壁厚度,所得数据进行统计分析.结果:唇侧、近中、远中牙体壁的厚度蒙古族均大于汉族,差异具有统计学意义(P<0.05),舌侧壁厚度对比差异无统计学意义.结论:汉族和蒙古族36~45岁人群的下颌切牙颈部牙体壁厚度存在一定的差异,从而为口腔临床治疗提供一定的理论依据.

  20. Numerical Comparison of Active Acoustic and Structural Noise Control in a Stiffened Double Wall Cylinder

    Science.gov (United States)

    Grosveld, Ferdinand W.

    1996-01-01

    The active acoustic and structural noise control characteristics of a double wall cylinder with and without ring stiffeners were numerically evaluated. An exterior monopole was assumed to acoustically excite the outside of the double wall cylinder at an acoustic cavity resonance frequency. Structural modal vibration properties of the inner and outer shells were analyzed by post-processing the results from a finite element analysis. A boundary element approach was used to calculate the acoustic cavity response and the coupled structural-acoustic interaction. In the frequency region of interest, below 500 Hz, all structural resonant modes were found to be acoustically slow and the nonresonant modal response to be dominant. Active sound transmission control was achieved by control forces applied to the inner or outer shell, or acoustic control monopoles placed just outside the inner or outer shell. A least mean square technique was used to minimize the interior sound pressures at the nodes of a data recovery mesh. Results showed that single acoustic control monopoles placed just outside the inner or outer shells resulted in better sound transmission control than six distributed point forces applied to either one of the shells. Adding stiffeners to the double wall structure constrained the modal vibrations of the shells, making the double wall stiffer with associated higher modal frequencies. Active noise control obtained for the stiffened double wall configurations was less than for the unstiffened cylinder. In all cases, the acoustic control monopoles controlled the sound transmission into the interior better than the structural control forces.

  1. Design of a Laboratory Hall Thruster with Magnetically Shielded Channel Walls, Phase III: Comparison of Theory with Experiment

    Science.gov (United States)

    Mikellides, Ioannis G.; Katz, Ira; Hofer, Richard R.; Goebel, Dan M.

    2012-01-01

    A proof-of-principle effort to demonstrate a technique by which erosion of the acceleration channel in Hall thrusters of the magnetic-layer type can be eliminated has been completed. The first principles of the technique, now known as "magnetic shielding," were derived based on the findings of numerical simulations in 2-D axisymmetric geometry. The simulations, in turn, guided the modification of an existing 6-kW laboratory Hall thruster. This magnetically shielded (MS) thruster was then built and tested. Because neither theory nor experiment alone can validate fully the first principles of the technique, the objective of the 2-yr effort was twofold: (1) to demonstrate in the laboratory that the erosion rates can be reduced by >order of magnitude, and (2) to demonstrate that the near-wall plasma properties can be altered according to the theoretical predictions. This paper concludes the demonstration of magnetic shielding by reporting on a wide range of comparisons between results from numerical simulations and laboratory diagnostics. Collectively, we find that the comparisons validate the theory. Near the walls of the MS thruster, theory and experiment agree: (1) the plasma potential has been sustained at values near the discharge voltage, and (2) the electron temperature has been lowered by at least 2.5-3 times compared to the unshielded (US) thruster. Also, based on carbon deposition measurements, the erosion rates at the inner and outer walls of the MS thruster are found to be lower by at least 2300 and 1875 times, respectively. Erosion was so low along these walls that the rates were below the resolution of the profilometer. Using a sputtering yield model with an energy threshold of 25 V, the simulations predict a reduction of 600 at the MS inner wall. At the outer wall ion energies are computed to be below 25 V, for which case we set the erosion to zero in the simulations. When a 50-V threshold is used the computed ion energies are below the threshold at both

  2. Comparison of central corneal thickness: ultrasound pachymetry versus slit-lamp optical coherence tomography, specular microscopy, and Orbscan

    Directory of Open Access Journals (Sweden)

    Khaja WA

    2015-06-01

    Full Text Available Wassia A Khaja, Sandeep Grover, Amy T Kelmenson, Lee R Ferguson, Kumar Sambhav, Kakarla V Chalam Department of Ophthalmology, University of Florida, College of Medicine, Jacksonville, FL, USA Background: Central corneal thickness (CCT can be measured by using contact and non-contact methods. Ultrasound pachymetry (US pachymetry is a contact method for measuring CCT and is perhaps the most commonly used method. However, non-contact methods like scanning slit topography (Orbscan II, slit-lamp optical coherence tomography (SL-OCT, and specular microscopy are also used. Not many studies have correlated the measurement of CCT with all four modalities. The purpose of this study was to compare and correlate the CCT measurements obtained by US pachymetry with SL-OCT, specular microscopy, and Orbscan. Method: This is a prospective, comparative study done in an institutional setting. Thirty-two eyes of 32 subjects with no known ocular disease and best-corrected visual acuity of 20/20 were enrolled. CCT measurements were obtained using SL-OCT, specular microscopy, scanning slit topography (Orbscan, and US pachymetry. Three measurements were made with each instrument by the same operator. Mean, standard deviation, and coefficient of variation were calculated for CCT measurements acquired by the four measurement devices. Bland–Altman plot was constructed to determine the agreements between the CCT measurements obtained by different equipment. Results: The mean CCT was 548.16±48.68 µm by US pachymetry. In comparison, CCT averaged 546.36±44.17 µm by SL-OCT, 557.61±49.92 µm by specular microscopy, and 551.03±48.96 µm by Orbscan for all subjects. Measurements by the various modalities were strongly correlated. Correlations (r2 of CCT, as measured by US pachymetry compared with other modalities, were: SL-OCT (r2=0.98, P<0.0001, specular microscopy (r2=0.98, P<0.0001, and Orbscan (r2=0.96, P<0.0001. All modalities had a linear correlation with US

  3. Contribution of CT Quantified Emphysema, Air Trapping and Airway Wall Thickness on Pulmonary Function in Male Smokers With and Without COPD

    NARCIS (Netherlands)

    Hoesein, Firdaus A. A. Mohamed; de Jong, Pim A.; Lammers, Jan-Willem J.; Mali, Willem P. Th. M.; Mets, Onno M.; Schmidt, Michael; de Koning, Harry J.; van der Aalst, Carlijn; Oudkerk, Matthijs; Vliegenthart, Rozemarijn; van Ginneken, Bram; van Rikxoort, Eva M.; Zanen, Pieter

    Emphysema, airway wall thickening and air trapping are associated with chronic obstructive pulmonary disease (COPD). All three can be quantified by computed tomography (CT) of the chest. The goal of the current study is to determine the relative contribution of CT derived parameters on spirometry,

  4. Imaging the Intracranial Atherosclerotic Vessel Wall Using 7T MRI : Initial Comparison with Histopathology

    NARCIS (Netherlands)

    van der Kolk, A. G.; Zwanenburg, J. J. M.; Denswil, N. P.; Vink, A.; Spliet, W. G. M.; Daemen, M. J. A. P.; Visser, F.; Klomp, D. W. J.; Luijten, P. R.; Hendrikse, J.

    2015-01-01

    In this preliminary study, 7T imaging was capable of identifying not only intracranial wall thickening but different plaque components such as foamy macrophages and collagen. Signal heterogeneity was typical of advanced atherosclerotic disease. BACKGROUND AND PURPOSE: Several studies have attempted

  5. Colon wall motility: comparison of novel quantitative semi-automatic measurements using cine MRI.

    Science.gov (United States)

    Hoad, C L; Menys, A; Garsed, K; Marciani, L; Hamy, V; Murray, K; Costigan, C; Atkinson, D; Major, G; Spiller, R C; Taylor, S A; Gowland, P A

    2016-03-01

    Recently, cine magnetic resonance imaging (MRI) has shown promise for visualizing movement of the colonic wall, although assessment of data has been subjective and observer dependent. This study aimed to develop an objective and semi-automatic imaging metric of ascending colonic wall movement, using image registration techniques. Cine balanced turbo field echo MRI images of ascending colonic motility were acquired over 2 min from 23 healthy volunteers (HVs) at baseline and following two different macrogol stimulus drinks (11 HVs drank 1 L and 12 HVs drank 2 L). Motility metrics derived from large scale geometric and small scale pixel movement parameters following image registration were developed using the post ingestion data and compared to observer grading of wall motion. Inter and intra-observer variability in the highest correlating metric was assessed using Bland-Altman analysis calculated from two separate observations on a subset of data. All the metrics tested showed significant correlation with the observer rating scores. Line analysis (LA) produced the highest correlation coefficient of 0.74 (95% CI: 0.55-0.86), p cine MRI registered data provides a quick, accurate and non-invasive method to detect wall motion within the ascending colon following a colonic stimulus in the form of a macrogol drink. © 2015 John Wiley & Sons Ltd.

  6. The True Portrayed Living World of Yi People in Liangshan Analyzing the Novel DARK STAIN ON THICK WALL%凉山彝人生存世界的真实再现——论《厚墙裂痕》

    Institute of Scientific and Technical Information of China (English)

    罗紫元

    2012-01-01

    马德清的长篇小说《厚墙裂痕》从凉山彝族地区天然景观和凉山彝族民间婚姻、丧葬、礼仪等习俗两个方面再现了凉山彝人生存的真实世界,具有民族志的书写特征。%Ma Deqing's novel" thick wall cracks" portrayed the true living world of Liangshan Yi People from Liangshan natural landscape and the Liangshan Yi Minority,which contains ethnography writing lea- tulles.

  7. Castability of ductile iron in thin walled castings (TWDI

    Directory of Open Access Journals (Sweden)

    M. Górny

    2008-10-01

    Full Text Available In work it has been presented results of influence of pouring temperature (Tp and carbon equivalent (CE on castability of ductile iron in thin walled castings with wall thickness of 1, 2 and 3 mm, respectively. Analysis was done on ductile iron with carbon equivalent ranging from 4.30 to 5.00 and pouring temperature varied from 1400 to 1500 oC. It has been shown that a statistical liner relationship exists between wall thickness and castability. Influence of CE and Tp on castability of cast iron flowing through channel with wall thickness of 2 and 3 mm can be presented by means of correlation equations (L = f(CE, Tp. Statistical analysis shows that pouring temperature has much higher influence on castability in comparison with influence of carbon equivalent.

  8. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry and Orbscan II Corneal Topography and Evaluation of Ultrasonic Pachymetry Repeatability

    Directory of Open Access Journals (Sweden)

    Semra Tiryaki Demir

    2014-08-01

    Full Text Available Objectives: Comparison of central corneal thickness (CCT measurements by ultrasonic pachymetry and Orbscan II corneal topography and evaluation of ultrasonic pachymetry repeatability for same observer. Materials and Methods: The study included 132, 82, and 80 eyes of 66 patients with primary open-angle glaucoma (POAG, 41 patients with ocular hypertension (OHT, and 40 controls, respectively. All subjects were subjected to routine ophthalmic examination. Orbscan II (Bausch&Lomb corneal topography and ultrasonic pachymetry (Nidek Ultrasonic Pachymetry UP-1000 were used for measurement of CCT. ANOVA (Turkey test was used for variable distribution, paired sample t-test was used for repeated measurements, and the analyses were done by SPSS 20.0. Results: Mean CCT was 558.9±37.2 µm by ultrasonic pachymetry and 553.4±37 µm by corneal topography. There was a significant difference between the two measurements (p0.05. CCT was 555±39.2 µm, 564.3±28.4 µm, and 559.7±41.5 µm by ultrasonic pachymetry in POAG, OHT, and control subjects, respectively; CCT was 550.3±38.3 µm, 558.5±28 µm, and 553.2±42.5 µm by Orbscan II corneal topography in POAG, OHT, and control subjects, respectively. There was a significant linear correlation between Orbscan II corneal topography and ultrasonic pachymetry in CCT measurements (r=0.975, p<0.0001. Repeatability of ultrasonic pachymetry for same observer was (ICC value 0.990. Conclusion: There is a significant correlation between Orbscan II corneal topography and ultrasonic pachymetry in CCT measurements. These two methods of measurements should not be substituted for each other, since ultrasonic pachymetry measures CCT greater than Orbscan II corneal topography. Repeatability of ultrasonic pachymetry for same observer is very high. (Turk J Ophthalmol 2014; 44: 263-7

  9. Navier-Stokes solutions of unsteady separation induced by a vortex: Comparison with theory and influence of a moving wall

    Science.gov (United States)

    Obabko, Aleksandr Vladimirovich

    Numerical solutions of the unsteady Navier-Stokes equations are considered for the flow induced by a thick-core vortex convecting along an infinite surface in a two-dimensional incompressible flow. The formulation is considered as a model problem of the dynamic-stall vortex and is relevant to other unsteady separation phenomena including vorticity ejections in juncture flows and the vorticity production mechanism in turbulent boundary-layers. Induced by an adverse streamwise pressure gradient due to the presence of the vortex above the wall, a primary recirculation region forms and evolves toward a singular solution of the unsteady non-interacting boundary-layer equations. The resulting eruptive spike provokes a small-scale viscous-inviscid interaction in the high-Reynolds-number regime. In the moderate-Reynolds-numbers regime, the growing recirculation region initiates a large-scale interaction in the form of local changes in the streamwise pressure gradient accelerating the spike formation and resulting small-scale interaction through development of a region of streamwise compression. It also was found to induce regions of streamwise expansion and "child" recirculation regions that contribute to ejections of near-wall vorticity and splitting of the "parent" region into multiple co-rotating eddies. These eddies later merge into a single amalgamated eddy that is observed to pair with the detaching vortex similar to the low-Reynolds-number regime where the large-scale interaction occurs, but there is no spike or subsequent small-scale interaction. It is also found that increasing the wall speed or vortex convection velocity toward a critical value results in solutions that are indicative of flows at lower Reynolds numbers eventually leading to suppression of unsteady separation and vortex detachment processes.

  10. Desmoid Tumor of the Anterior Abdominal Wall in Female Patients: Comparison with Endometriosis

    Directory of Open Access Journals (Sweden)

    H. Krentel

    2012-01-01

    Full Text Available In female patients presenting a tumor of the lower abdominal wall especially after cesarian section, an endometriotic tumor as well as an aggressive desmoid tumor should be considered. Symptoms in correlation with the monthly period can facilitate the presurgical differentiation between endometriosis and fibromatosis. Ultrasound reveals the typical location of both tumors and its remarkable sonographic appearance. In the clinical practice, the desmoid fibromatosis of the lower abdominal wall is a very rare disease. We present a case of a 25-year-old pregnant and discuss diagnostic and therapeutic options by a PubMed literature review. With the knowledge of the prognosis of the desmoid fibromatosis and the respective treatment options including wait and see, complete surgical resection with macroscopically free margins and adjuvant approaches is essential to avoid further interventions and progression of the locally destructive tumor.

  11. Comparison of scrape-off layer transport in inner and outer wall limited JET plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, C., E-mail: csilva@ipfn.ist.utl.pt [Associação Euratom/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica Lisboa (Portugal); Arnoux, G.; Devaux, S. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Frigione, D. [Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma (Italy); Groth, M. [Aalto University, Association EURATOM-Tekes, Otakaari 4, 02015 Espoo (Finland); Horacek, J. [Institute of Plasma Physics AS CR, v.v.i., Association EURATOM/IPP.CR, Praha 8 (Czech Republic); Lomas, P.J. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Marsen, S. [Max-Planck-Institute for Plasma Physics, EURATOM Association, 17491 Greifswald (Germany); Matthews, G. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Pitts, R.A. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

    2013-07-15

    The JET scrape-off layer has been characterized with a reciprocating probe in inner wall, IW, and outer wall, OW, limited plasmas. Broad SOL profiles are observed for IW limited plasmas with power e-folding length substantially larger (by a factor of ∼5–7.5) than in OW limited plasmas. The properties of the fluctuations in the SOL parameters indicate larger turbulent transport for IW limited plasmas. The striking differences observed between IW and OW limited plasmas on the power e-folding length, parallel flow, turbulent transport as well as the characteristics of the fluctuations support the existence of a poloidally localized region of enhanced radial transport near the outboard midplane. The dependence of the SOL power e-folding length on the main plasma parameters was also investigated for IW limited plasmas and a modest negative dependence on both the plasma current and the line-averaged density found.

  12. Assessment of posterior vaginal wall prolapse: comparison of physical findings to cystodefecoperitoneography.

    Science.gov (United States)

    Altman, Daniel; López, Annika; Kierkegaard, Jonas; Zetterström, Jan; Falconer, Christian; Pollack, Johan; Mellgren, Anders

    2005-01-01

    The aim of the present study was to compare clinical and radiological findings when assessing posterior vaginal wall prolapse. Defecography can be used to complement the clinical evaluation in patients with posterior vaginal wall prolapse. Further development of the defecography technique, using contrast medium in the urinary bladder and intraperitoneally, have resulted in cystodefecoperitoneography (CDP). Thirty-eight women underwent clinical examination using the pelvic organ prolapse quantification system (POP-Q) followed by CDP. All patients answered a standardized bowel function questionnaire. Statistical analysis measuring correlation between POP-Q and CDP using Pearson's correlation coefficient (r) and Spearman's rank order correlation coefficient (rs) demonstrated a poor to moderate correlation, r=0.49 and rs=0.55. Although there was a strong association between large rectoceles (>3 cm) at CDP and symptoms of rectal emptying difficulties (p<0.001), severity and prevalence of bowel dysfunction showed poor coherence with clinical prolapse staging and findings at radiological imaging. Vaginal topography and POP-Q staging predict neither radiological size nor visceral involvement in posterior vaginal wall prolapse. Radiological evaluation may therefore be a useful complement in selected patients.

  13. An Inquiry into the Life Cycle of Systems of Inner Walls: Comparison of Masonry and Drywall

    Directory of Open Access Journals (Sweden)

    Karina Condeixa

    2015-06-01

    Full Text Available Life Cycle Assessment is a methodology that investigates impacts linked to a product or service during its entire life cycle. Life Cycle Assessment studies investigate processes and sub-processes in a fragmented way to ascertain their inputs, outputs and emissions and get an overview of the generating sources of their environmental loads. The lifecycle concept involves all direct and indirect processes of the studied object. This article aims to model the material flows in the masonry and drywall systems and internal walls in a Brazilian scenario, and calculate the climate change impacts generated by the transport of the component materials of the systems. Internal walls of a residential dwelling in Rio de Janeiro are analyzed from a qualitative inventory of all life cycles with an analysis of material flows, based on technical and academic literature. All Life Cycle Impact Assessment of the systems is carried out with international data from the database, and using the IPCC2013 method for climate change impacts. This study disregards the refurbishment and possible extensions within the use phase. Thus, the inventory identifies weaknesses of the systems while the impact assessment validates the results. This study allows us a complete understanding about the inner walls systems in the Brazilian scenario, evidencing its main weaknesses and subsidizes decision-making for the industry and for planning of the new buildings.

  14. Liquid Wall Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  15. NIF Periscope Wall Modal Study Comparison of Results for 2 FEA Models with 2 Modal Tests

    Energy Technology Data Exchange (ETDEWEB)

    Eli, M W; Gerhard, M A; Lee, C L; Sommer, S C; Woehrle, T G

    2000-10-26

    This report summarizes experimentally and numerically determined modal properties for one of the reinforced concrete end walls of the NIF Periscope Support Structure in Laser Bay 1. Two methods were used to determine these modal properties: (1) Computational finite-element analyses (modal extraction process); and (2) Experimental modal analysis based on measured test data. This report also includes experimentally determined modal properties for a prototype LM3/Polarizer line-replaceable unit (LRU) and a prototype PEPC LRU. Two important parameters, used during the design phase, are validated through testing [ref 1]. These parameters are the natural frequencies and modal damping (of the system in question) for the first several global modes of vibration. Experimental modal testing provides these modal values, along with the corresponding mode shapes. Another important parameter, the input excitation (expected during normal operation of the NIF laser system) [ref 1], can be verified by performing a series of ambient vibration measurements in the vicinity of the particular system (or subsystem) of interest. The topic of ambient input excitation will be covered in a separate report. Due to the large mass of the Periscope Pedestal, it is difficult to excite the entire series of Periscope Pedestal Walls all at once. It was decided that the experimental modal tests would be performed on just one Periscope End Wall in Laser Bay 1. Experimental modal properties for the Periscope End Wall have been used to validate and update the FE analyses. Results from the analyses and modal tests support the conclusion that the Periscope Pedestal will not exceed the stability budget, which is described in reference 1. The results of the modal tests for the Periscope End Wall in Laser Bay 1 have provided examples of modal properties that can be derived from future modal tests of the entire Periscope Assembly (excluding the LRU's). This next series of larger modal tests can be

  16. Development of automated welding processes for field fabrication of thick-walled pressure vessels: electron beam method. Sixth quarterly report, January 1-March 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.M.

    1979-01-01

    Research is reported of a project to develop and demonstrate an electron beam welding procedure for welding 8'' thick SA 387 Grade 22 Class 2 (2-1/4 Cr-1 Mo) steel. A total of 414 welds have been made to date. Partial penetration welding procedures capable of producing defect-free, 4'' welds have been developed in the horizontal position. Beam oscillation conditions strongly influence welding performance. Defect-free, partial penetration welds have been made at vacuum pressures of up to 30 microns. Several 8'' thick, defect-free welds have been made in the horizontal position. Attempts to produce defect-free, partial penetration welds in the vertical position have been unsuccessful.

  17. Comparison between muscle activation measured by electromyography and muscle thickness measured using ultrasonography for effective muscle assessment.

    Science.gov (United States)

    Kim, Chang-Yong; Choi, Jong-Duk; Kim, Suhn-Yeop; Oh, Duck-Won; Kim, Jin-Kyung; Park, Ji-Whan

    2014-10-01

    In this study, we aimed to compare the intrarater reliability and validity of muscle thickness measured using ultrasonography (US) and muscle activity via electromyography (EMG) during manual muscle testing (MMT) of the external oblique (EO) and lumbar multifidus (MF) muscles. The study subjects were 30 healthy individuals who underwent MMT at different grades. EMG was used to measure the muscle activity in terms of ratio to maximum voluntary contraction (MVC) and root mean square (RMS) metrics. US was used to measure the raw muscle thickness, the ratio of muscle thickness at MVC, and the ratio of muscle thickness at rest. One examiner performed measurements on each subject in 3 trials. The intrarater reliabilities of the % MVC RMS and raw RMS metrics for EMG and the % MVC thickness metrics for US were excellent (ICC=0.81-0.98). There was a significant difference between all the grades measured using the % MVC thickness metric (pEMG measurement methods than with the others (r=0.51-0.61). Our findings suggest that the % MVC thickness determined by US was the most sensitive of all methods for assessing the MMT grade.

  18. Comparison of the changes of alveolar bone thickness in maxillary incisor area in extraction and non-extraction cases: computerized tomography evaluation

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Barroso Picanço

    2013-10-01

    Full Text Available OBJECTIVE: To compare, through computed tomography, alveolar bone thickness changes at the maxillary incisors area during orthodontic treatment with and without tooth extraction. METHODS: Twelve patients were evaluated. They were divided into 2 groups: G1 - 6 patients treated with extraction of right and left maxillary first premolars, with mean initial age of 15.83 years and mean treatment length of 2.53 years; G2 - 6 patients treated without extraction, with mean initial age of 18.26 years and mean treatment length of 2.39 years. Computed tomographies, lateral cephalograms and periapical radiographs were used at the beginning of the treatment (T1 and 18 months after the treatment had started (T2. Extraction space closure occurred in the extraction cases. Intragroup and intergroup comparisons were performed by dependent and independent t test, respectively. RESULTS: In G1, the central incisor was retracted and uprighted, while in G2 this tooth showed vestibularization. Additionally, G1 presented a higher increase of labial alveolar bone thickness at the cervical third in comparison with G2. The incidence of root resorption did not present significant differences between groups. CONCLUSION: There were no changes in alveolar bone thickness when extraction and nonextraction cases were compared, except for the labial alveolar bone thickness at the cervical third of maxillary incisors.

  19. Wall relaxation in growing stems: comparison of four species and assessment of measurement techniques

    Science.gov (United States)

    Cosgrove, D. J.

    1987-01-01

    This study was carried out to develop improved methods for measuring in-vivo stress relaxation of growing tissues and to compare relaxation in the stems of four different species. When water uptake by growing tissue is prevented, in-vivo stress relaxation occurs because continued wall loosening reduces wall stress and cell turgor pressure. With this procedure one may measure the yield threshold for growth (Y), the turgor pressure in excess of the yield threshold (P-Y), and the physiological wall extensibility (phi). Three relaxation techniques proved useful: "turgor-relaxation", "balance-pressure" and "pressure-block". In the turgor-relaxation method, water is withheld from growing tissue and the reduction in turgor is measured directly with the pressure probe. This technique gives absolute values for P and Y, but requires tissue excision. In the balance-pressure technique, the excised growing region is sealed in a pressure chamber, and the subsequent reduction in water potential is measured as the applied pressure needed to return xylem sap to the cut surface. This method is simple, but only measures (P-Y), not the individual values of P and Y. In the pressure-block technique, the growing tissue is sealed into a pressure chamber, growth is monitored continuously, and just sufficient pressure is applied to the chamber to block growth. The method gives high-resolution kinetics of relaxation and does not require tissue excision, but only measures (P-Y). The three methods gave similar results when applied to the growing stems of pea (Pisum sativum L.), cucumber (Cucumis sativus L.), soybean (Glycine max (L.) Merr.) and zucchini (Curcubita pepo L.) seedlings. Values for (P-Y) averaged between 1.4 and 2.7 bar, depending on species. Yield thresholds averaged between 1.3 and 3.0 bar. Compared with the other methods, relaxation by pressure-block was faster and exhibited dynamic changes in wall-yielding properties. The two pressure-chamber methods were also used to measure

  20. Wall relaxation in growing stems: comparison of four species and assessment of measurement techniques

    Science.gov (United States)

    Cosgrove, D. J.

    1987-01-01

    This study was carried out to develop improved methods for measuring in-vivo stress relaxation of growing tissues and to compare relaxation in the stems of four different species. When water uptake by growing tissue is prevented, in-vivo stress relaxation occurs because continued wall loosening reduces wall stress and cell turgor pressure. With this procedure one may measure the yield threshold for growth (Y), the turgor pressure in excess of the yield threshold (P-Y), and the physiological wall extensibility (phi). Three relaxation techniques proved useful: "turgor-relaxation", "balance-pressure" and "pressure-block". In the turgor-relaxation method, water is withheld from growing tissue and the reduction in turgor is measured directly with the pressure probe. This technique gives absolute values for P and Y, but requires tissue excision. In the balance-pressure technique, the excised growing region is sealed in a pressure chamber, and the subsequent reduction in water potential is measured as the applied pressure needed to return xylem sap to the cut surface. This method is simple, but only measures (P-Y), not the individual values of P and Y. In the pressure-block technique, the growing tissue is sealed into a pressure chamber, growth is monitored continuously, and just sufficient pressure is applied to the chamber to block growth. The method gives high-resolution kinetics of relaxation and does not require tissue excision, but only measures (P-Y). The three methods gave similar results when applied to the growing stems of pea (Pisum sativum L.), cucumber (Cucumis sativus L.), soybean (Glycine max (L.) Merr.) and zucchini (Curcubita pepo L.) seedlings. Values for (P-Y) averaged between 1.4 and 2.7 bar, depending on species. Yield thresholds averaged between 1.3 and 3.0 bar. Compared with the other methods, relaxation by pressure-block was faster and exhibited dynamic changes in wall-yielding properties. The two pressure-chamber methods were also used to measure

  1. Biomechanical comparison of different stabilization constructs for unstable posterior wall fractures of acetabulum. A cadaveric study.

    Directory of Open Access Journals (Sweden)

    Yuntong Zhang

    Full Text Available PURPOSE: Operative treatment of unstable posterior wall fractures of acetabulum has been widely recommended. This laboratory study was undertaken to evaluate static fixation strength of three common fixation constructs: interfragmentary screws alone, in combination with conventional reconstruction plate, or locking reconstruction plate. METHODS: Six formalin-preserved cadaveric pelvises were used for this investigation. A posterior wall fracture was created along an arc of 40-90 degree about the acetabular rim. Three groups of different fixation constructs (two interfragmentary screws alone; two interfragmentary screws and a conventional reconstruction plate; two interfragmentary screws and a locking reconstruction were compared. Pelvises were axial loaded with six cycles of 1500 N. Dislocation of superior and inferior fracture site was analysed with a multidirectional ultrasonic measuring system. RESULTS: No statistically significant difference was found at each of the superior and inferior fracture sites between the three types of fixation. In each group, the vector dislocation at superior fracture site was significantly larger than inferior one. CONCLUSIONS: All those three described fixation constructs can provide sufficient stability for posterior acetabular fractures and allow early mobilization under experimental conditions. Higher posterior acetabular fracture line, transecting the weight-bearing surface, may indicate a substantial increase in instability, and need more stable pattern of fixation.

  2. Assessment of left ventricular regional wall motion by color kinesis technique: comparison with angiographic findings.

    Science.gov (United States)

    Vermes, E; Guyon, P; Weingrod, M; Otmani, A; Soussana, C; Halphen, C; Leroy, G; Haïat, R

    2000-08-01

    The analysis of segmental wall motion using two-dimensional (2-D) echocardiography is subjective with high interobserver variability. Color kinesis is a new technique providing a color-encoded map of endocardial motion. We evaluated the accuracy of color kinesis and 2-D for assessment of regional asynergy compared with left ventricular angiography as a reference method. Fifteen patients admitted for myocardial infarction were studied by echocardiography the day before left ventricular angiography. The left ventricle was divided into seven segments. Each segment was classified by two independent observers as normal or abnormal in 2-D and color kinesis. Accuracy of color kinesis and 2-D was evaluated and compared to left ventricular angiography. Color kinesis is significantly superior to 2-D for all seven segments (mean 0.80/0.68, P = 0.05), except for the septum (0.67/0.60, P = NS). Interobserver variability studied by chi-square statistic is lower with color kinesis (0.70) than with 2-D (0.57). We conclude that these data suggest that color kinesis is a useful method for assessing systolic wall motion in all segments, except the septum and for improving the accuracy of segmental ventricular function and interobserver variability.

  3. Comparison of wall thickening and perfusion analysis in cardiomyopathy by gated Tc-99m MIBI

    Energy Technology Data Exchange (ETDEWEB)

    Cho, I.; Chun, K.; Won, K.; Lee, H.; Park, J.; Shin, D.; Kim, Y.; Shim, B [Yeungnam University Hospital, Taegu (Korea, Republic of)

    2002-07-01

    The objective of this study was to clarify the relationship between left ventriculr (LV) function, wall thickening (WT) and perfusion in cardiomyopathy. Twenty-six cases (15 males, 11 females: mean age, 58 y), consisting of 10 healthy control subjects, 10 patients with hypertrophic cardiomyopathy (HCM) and 6 patients with idiopathic dilated cardiomyopathy (DCM) was studied with gated Tc-99m MIBI SPECT. LV WT, LV perfusion and function (LV wall motion, LVEDV, LVESV and LVEF) by using gated SPECT quantification and CEqual software were analysed. In HCM and DCM group, mean WT was significantly decreased. (HCM: 15.2{+-}6.7%, DCM: 4.9%, control: 34.1{+-}4.9% (p<0.01). Adenosine stress test didn't show any reversible or fixed perfusion defects in all HCM patients, controls and five DCM patients except one patient (but, no coronary artery stenosis in coronary angiography). LVEF for HCM, DCM and control was 48.4{+-}13.2%, 28.7{+-}8.8%, 62.7{+-}9.5%, respectively (p<0.05)). LVEDV and LVESV didn't show a significant differences between HCM and control group, not DCM group. In HCM, WT was decreased as like DCM even though LV myocardial perfusion and function was reserved.

  4. Detection of coronary plaques using MR coronary vessel wall imaging: validation of findings with intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Gerretsen, Suzanne; Engelshoven, Jos M.A. van; Kooi, M.E. [Maastricht University Medical Centre, Department of Radiology, Maastricht (Netherlands); Maastricht University, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); Kessels, Alfons G. [Maastricht University Medical Centre, Department of Clinical Epidemiology and Medical Technical Assessment, Maastricht (Netherlands); Nelemans, Patty J. [Maastricht University, Department of Epidemiology, Maastricht (Netherlands); Dijkstra, Jouke; Reiber, Johan H.C.; Geest, Rob J. van der [Leiden University Medical Centre, Department of Radiology, Division of image processing (LKEB), Leiden (Netherlands); Katoh, Marcus [HELIOS Clinic, Department of Diagnostic and Interventional Radiology, Krefeld (Germany); Waltenberger, Johannes [University of Muenster, Department of Cardiology and Angiology, Muenster (Germany); Botnar, Rene M. [King' s College, Imaging Sciences Division, London (United Kingdom); Leiner, Tim [Maastricht University Medical Centre, Department of Radiology, Maastricht (Netherlands); Maastricht University, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); Utrecht University Medical Centre, Department of Radiology, Utrecht (Netherlands)

    2013-01-15

    Compared with X-ray coronary angiography (CAG), magnetic resonance imaging of the coronary vessel wall (MR-CVW) may provide more information about plaque burden and coronary remodelling. We compared MR-CVW with intravascular ultrasound (IVUS), the standard of reference for coronary vessel wall imaging, with regard to plaque detection and wall thickness measurements. In this study 17 patients with chest pain, who had been referred for CAG, were included. Patients underwent IVUS and MR-CVW imaging of the right coronary artery (RCA). Subsequently, the coronary vessel wall was analysed for the presence and location of coronary plaques. Fifty-two matching RCA regions of interest were available for comparison. There was good agreement between IVUS and MR-CVW for qualitative assessment of presence of disease, with a sensitivity of 94% and specificity of 76%. Wall thickness measurements demonstrated a significant difference between mean wall thickness on IVUS and MR-CVW (0.48 vs 1.24 mm, P < 0.001), but great heterogeneity between wall thickness measurements, resulting in a low correlation between IVUS and MR-CVW. MR-CVW has high sensitivity for the detection of coronary vessel wall thickening in the RCA compared with IVUS. However, the use of MRI for accurate absolute wall thickness measurements is not supported when a longitudinal acquisition orientation is used. (orig.)

  5. Development of automated welding processes for field fabrication of thick-walled pressure vessels: electron beam method. Fifth quarterly report, October 1--December 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.M.

    1978-01-01

    This is the fifth quarterly report of a project to develop and demonstrate an electron beam welding procedure for welding 8'' thick SA 387 Grade 22 Class 2 (2-1/4 Cr--1 Mo) steel. A total of 324 welds have been made to date. Much difficulty has been encountered in the past in attempts to make partial penetration welds (4-1/2'' deep) which do not have a necklace defect. However, a beam oscillation pattern, the horseshoe pattern, has been successfully used to make defect-free, partial penetration welds in the horizontal position. An 8'' thick, defect-free weld was made. Determination of the optimum welding procedure has not yet been made though. For welding in the vertical position, a shoe was designed and used to make void-free, partial penetration welds. A welding procedure which produces defect-free welds in the vertical position has not yet been developed.

  6. Comparison of cellular toxicity between multi-walled carbon nanotubes and onion-like shell-shaped carbon nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Seunghyon [Seoul National University, School of Mechanical and Aerospace Engineering (Korea, Republic of); Kim, Ji-Eun [Korea Research Institute of Standard and Science, Center for NanoSafety Metrology, Division of Convergence Technology (Korea, Republic of); Kim, Daegyu [LG Electronics (Korea, Republic of); Woo, Chang Gyu [Korea Institute of Machinery and Materials, Environmental and Energy Systems Research Division (Korea, Republic of); Pikhitsa, Peter V. [Seoul National University, School of Mechanical and Aerospace Engineering (Korea, Republic of); Cho, Myung-Haing, E-mail: mchotox@snu.ac.kr [Seoul National University, Laboratory of Toxicology, College of Veterinary Medicine (Korea, Republic of); Choi, Mansoo, E-mail: mchoi@snu.ac.kr [Seoul National University, School of Mechanical and Aerospace Engineering (Korea, Republic of)

    2015-09-15

    The cellular toxicity of multi-walled carbon nanotubes (MWCNTs) and onion-like shell-shaped carbon nanoparticles (SCNPs) was investigated by analyzing the comparative cell viability. For the reasonable comparison, physicochemical characteristics were controlled thoroughly such as crystallinity, carbon bonding characteristic, hydrodynamic diameter, and metal contents of the particles. To understand relation between cellular toxicity of the particles and generation of reactive oxygen species (ROS), we measured unpaired singlet electrons of the particles and intracellular ROS, and analyzed cellular toxicity with/without the antioxidant N-acetylcysteine (NAC). Regardless of the presence of NAC, the cellular toxicity of SCNPs was found to be lower than that of MWCNTs. Since both particles show similar crystallinity, hydrodynamic size, and Raman signal with negligible contribution of remnant metal particles, the difference in cell viability would be ascribed to the difference in morphology, i.e., spherical shape (aspect ratio of one) for SCNP and elongated shape (high aspect ratio) for MWCNT.

  7. In vitro, time-resolved PIV comparison of the effect of stent design on wall shear stress.

    Science.gov (United States)

    Charonko, John; Karri, Satyaprakash; Schmieg, Jaime; Prabhu, Santosh; Vlachos, Pavlos

    2009-07-01

    The effect of stent design on wall shear stress (WSS) and oscillatory shear index (OSI) was studied in vitro using time-resolved digital particle image velocimetry (DPIV). Four drug-eluting stents [XIENCE V (Abbott Vascular), TAXUS Liberté (Boston Scientific), Endeavor (Medtronic), and Cypher (J&J Cordis)] and a bare-metal stent [VISION (Abbott Vascular)] were implanted into compliant vessel models, and the flow was measured in physiologically accurate coronary conditions featuring reversal and realistic offsets between pressure and flowrate. DPIV measurements were made at three locations under two different flow rates (resting: Re = 160, f = 70 bpm and exercise: Re = 300, f = 120 bpm). It was observed that design substantially affected the WSS experienced at the vessel walls. Averaged values between struts ranged from 2.05 dynes/cm(2) (Cypher) to 8.52 dynes/cm(2) (XIENCE V) in resting conditions, and from 3.72 dynes/cm(2) (Cypher) to 14.66 dynes/cm(2) (VISION) for the exercise state. Within the stent, the WSS dropped and the OSI increased immediately distal to each strut. In addition, an inverse correlation between average WSS and OSI existed. Comparisons with recently published results from animal studies show strong correlation between the measured WSS and observed endothelial cell coverage. These results suggest the importance of stent design on the WSS experienced by endothelial cells in coronary arteries.

  8. THE COMPARISON OF STRENGTH PROPERTY BETWWEEN KRAFT PULP AND ALKALINE SULFITE-ANTHRAQUINONE PULP FOR THICKER CELL WALL FIBER MATERIALS

    Institute of Scientific and Technical Information of China (English)

    Li Li; Feifei Wang; Yunzhan Zhang

    2004-01-01

    The comparison of strength property between kraft pulp ( KP ) and Alkaline Sulfite-Anthraquinone (AS-AQ) pulp for thicker cell wall fiber materials Larch and Quercus as examples was studied. The average coefficient of flexibility of Larch and Quercus are 0.6-0.7 and 0.45-0.50, respectively. The results showed that the strength property of thicker cell wall pulp is some what different from those reported earlier. The strengths of AS-AQ are all higher than those of KP for Larch and Quercus. For Larch, under same beating degree the breaking length of AS-AQ is 8-16% higher than that of KP, burst index 3-14% higher, folding endurance 30% higher,tear index slightly higher. For Quercus, the breaking length of AS-AQ is 5-10% higher then that of KP,burst index 10-15% higher, folding endurance 30-50% higher, tear index 5-15% higher. Under the same breaking length the tear index of AS-AQ pulp is significantly higher than that of KP for both Larch and Quercus.

  9. THE COMPARISON OF STRENGTH PROPERTY BETWWEEN KRAFT PULP AND ALKALINE SULFITE-ANTHRAQUINONE PULP FOR THICKER CELL WALL FIBER MATERIALS

    Institute of Scientific and Technical Information of China (English)

    LiLi; FeifeiWang; YunzhanZhang

    2004-01-01

    The comparison of strength property between kraftpulp ( KP ) and Alkaline Sulfite-Anthraquinone(AS-AQ) pulp for thicker cell wall fiber materialsLarch and Quercus as examples was studied. Theaverage coefficient of flexibility of Larch andQuercus are 0.6-0.7 and 0.45-0.50, respectively. Theresults showed that the strength property of thickercell wall pulp is some what different from thosereported earlier. The strengths of AS-AQ are allhigher than those of KP for Larch and Quercus. ForLarch, under same beating degree the breaking lengthof AS-AQ is 8-16% higher than that of KP, burstindex 3-14% higher, folding endurance 30% higher,tear index slightly higher. For Quercus, the breakinglength of AS-AQ is 5-10% higher then that of KP,burst index 10-15% higher, folding endurance30-50% higher, tear index 5-15% higher. Under thesame breaking length the tear index of AS-AQ pulpis significantly higher than that of KP for both Larchand Quercus.

  10. Nonlinear incompressible finite element for simulating loading of cardiac tissue--Part II: Three dimensional formulation for thick ventricular wall segments.

    Science.gov (United States)

    Horowitz, A; Sheinman, I; Lanir, Y

    1988-02-01

    A three dimensional incompressible and geometrically as well as materially nonlinear finite element is formulated for future implementation in models of cardiac mechanics. The stress-strain relations in the finite element are derived from a recently proposed constitutive law which is based on the histological composition of the myocardium. The finite element is formulated for large deformations and considers incompressibility by introducing the hydrostatic pressure as an additional variable. The results of passive loading cases simulated by this element allow to analyze the mechanical properties of ventricular wall segments, the main of which are that the circumferential direction is stiffer than the longitudinal one, that its shear stiffness is considerably lower than its tensile and compressive stiffness and that, due to its mechanically prominent role, the collagenous matrix may affect the myocardial perfusion.

  11. Comparison between laboratory measurements, simulations, and analytical predictions of the transverse wall impedance at low frequencies

    CERN Document Server

    Roncarolo, F; Kroyer, T; Metral, E; Mounet, N; Salvant, B; Zotter, B

    2009-01-01

    The prediction of the transverse wall beam impedance at the first unstable betatron line (8 kHz) of the CERN Large Hadron Collider (LHC) is of paramount importance for understanding and controlling the related coupled-bunch instabilities. Until now only novel analytical formulas were available at this frequency. Recently, laboratory measurements and numerical simulations were performed to cross-check the analytical predictions. The experimental results based on the measurement of the variation of a probe coil inductance in the presence of (i) sample graphite plates, (ii) stand-alone LHC collimator jaws, and (iii) a full LHC collimator assembly are presented in detail. The measurement results are compared to both analytical theories and simulations. In addition, the consequences for the understanding of the LHC impedance are discussed.

  12. Comparison of canal wall incisions for tympanoplasty for large central perforations

    Directory of Open Access Journals (Sweden)

    Sohil I Vadiya

    2015-01-01

    Full Text Available Aim and Objective: To compare surgical outcomes with different canal wall incisions used in common practice for tympanoplasty for large perforations. Materials and Methods: Totally 88 patients included in the study and three groups formed. Group A consisted of 35 patients and the vascular strip incision with anterior tucking (VSAT technique used in these patients. Group B consisted of 31 patients and the tympanometal flap with anterior tucking (TMFAT technique used in these patients. Group C had 22 patients and the near full cuff (NFC technique used in them. Results: Success rate of 97.15% observed for Group A, 93.55% observed for Group B and 86.36% observed for Group C patients. Most of the patients in Group A had healing time <4 weeks, whereas most patients in Group C had more than 5 weeks of healing time. Granulations were not seen in Group A, whereas 3 among Group B and 4 among Group C patients developed granulations. Canal wall sagging was seen in 1 among Group A, 2 among Group B and 4 among Group C patients. The average hearing gain in terms of improvement in air-bone gap for Groups A, B and C have been 19.62, 19.25 and 17.35 db, respectively. Conclusion: The VSAT is the method of choice in terms of better success rates and minimum canal skin related complications in postoperative period. The VSAT also provides good exposure during surgery. Hearing gain in Group A is significantly better than Group C (P = 0.023.

  13. Residual and Dynamic Range of Retinal Nerve Fiber Layer Thickness in Glaucoma: Comparison of Three OCT Platforms

    Science.gov (United States)

    Mwanza, Jean-Claude; Kim, Hanna Y.; Budenz, Donald L.; Warren, Joshua L.; Margolis, Michael; Lawrence, Scott D.; Jani, Pooja D.; Thompson, Garrett S.; Lee, Richard K.

    2015-01-01

    Purpose To estimate visual field (VF) sensitivity at which retinal nerve fiber layer (RNFL) thinning reaches the measurement floor and at which RNFL stops thinning (change points), the dynamic range of RNFL thickness, and the number of steps from normal to RNFL floor among three optical coherence tomography (OCT) devices. Methods Glaucomatous patients (n = 58) and healthy subjects (n = 55–60) prospectively underwent VF testing and RNFL thickness measurement with Cirrus, Spectralis, and RTVue. Change points and corresponding RNFL thicknesses were estimated with simple linear regression (SLR) and Bayesian change point (BCP) analyses. The dynamic range and number of steps to RNFL floor were determined. Results The average VF change points and corresponding residual thickness at the time RNFL stopped thinning were −22.2 dB and 57.0 μm (Cirrus), −25.3 dB and 49.2 μm (Spectralis), and −24.6 dB and 64.7 μm (RTVue). The RNFL dynamic ranges derived from SLR values were wider on Spectralis (52.6 μm) than on Cirrus (35.4 μm) and RTVue (35.5 μm); the corresponding number of steps to reach the RNFL floor were 9.0 on Cirrus, 10.6 on Spectralis, and 8.3 on RTVue. Conclusions The relative VF sensitivity at which average RNFL thickness reaches the measurement floor, the residual layer thickness, and RNFL dynamic measurement range differ among the three devices. However, the number of steps from normal to the RNFL thickness floor is comparable. PMID:26436887

  14. Development of an instrument for wall thickness measurement for stability testing of suspended API tubes in mineshafts; Entwicklung eines Wanddicken-Messgeraetes zum Pruefen der Standsicherheit von im Schacht freihaengenden API-Rohrleitungen

    Energy Technology Data Exchange (ETDEWEB)

    Hufendiek, H.W.; Gronau, O. [Deutsche Montan Technologie GmbH, Bochum (Germany). Car Synergies Division

    2001-07-01

    As suspended tubes in mineshafts are getting more common, corrosion and wear will reduce wall thickness of tubes and tube joints and affect their operating characteristics. In the context of a R + D project funded by the state of Nordrhein-Westfalen from 1992 through 1994, the TesTec Department carried out measurements on suspended tubes in coal mines. It was found that suspended tubes will still function without problems with a 25% wall thickness reduction. So far, there was no satisfactory method of measuring the real wall thickness of the tube joints. In the case of the tubes themselves, there are several options, e.g. US point measurements from outside, indirect measurements using mechanical probes, and ultrasonic measurements of fluids from inside. The TesTec Department proved that magnetic induction sensors commonly used in steel cable testing can be used for measuring corrosion damage and cross section reductions. Preliminary tests were carried out on tubes and plates for this purpose. The TesTec instrument will be modified into a test pig for monitoring suspended tubes in mineshafts. [German] Rohrleitungen in Schaechten des Ruhrbergbaus werden immer haeufiger als freihaengende Leitungen ausgefuehrt. Korrosion und Verschleiss fuehren zu Minderungen der Wandstaerken in den Rohrleitungen und deren Muffenverbindungen und damit zu einer Verminderung der Tragfaehigkeit. Untersuchungen des Geschaeftsbereiches TesTec im Rahmen eines vom Land Nordrhein-Westfalen bezuschussten Untersuchungs- und Entwicklungsvorhabens in der Zeit von 1992 bis 1994 haben gezeigt, dass unter Beruecksichtigung statischer und dynamischer Belastungen des Rohrleitungssystems eine bis zu 25%-ige Querschnittsminderung noch einen sicheren Betrieb gewaehrleistet. Fuer die Bestimmung des tatsaechlichen Restquerschnitts, insbesondere im Muffenbereich, gibt es bisher keine zufriedenstellende Messmethode. Die Erfassung der tatsaechlichen Wanddicke der Rohre is von aussen z.B. durch punktuelle US

  15. A comparison of brain volume and cortical thickness in excoriation (skin picking) disorder and trichotillomania (hair pulling disorder) in women.

    Science.gov (United States)

    Roos, Annerine; Grant, Jon E; Fouche, Jean-Paul; Stein, Dan J; Lochner, Christine

    2015-02-15

    Skin picking disorder (SPD) and trichotillomania (hair pulling disorder, or HPD) significantly overlap in terms of clinical features. However, few studies have directly compared structural brain data in these disorders. The aim of this study was to compare volumes of brain structures and cortical thickness in patients with SPD and HPD, and determine involvement of fronto-striatal pathways. Seventeen female SPD, 17 HPD and 15 healthy age-matched controls underwent clinical assessment and structural MRI imaging. Group differences were determined in brain volume and cortical thickness, controlling for illness severity. Participants with SPD had greater volume of the ventral striatum bilaterally; and reduced cortical thickness in right hemisphere frontal areas, and greater thickness of the cuneus bilaterally compared to HPD and control participants. HPD participants demonstrated reduced thickness of the right parahippocampal gyrus compared to SPD and control participants. The findings here are partially consistent with previous structural work in SPD, and suggest some differences in the neurobiology of SPD and HPD. The more extensive involvement of the ventral striatum in SPD may suggest greater involvement of the reward system, while the more extensive involvement of the parahippocampal gyrus in HPD may be consistent with the dissociative symptoms often seen in these patients.

  16. Comparison of phacoemulsification parameters effect on macular thickness changes after uneventful phacoemulsification in diabetic and non-diabetic patients

    Directory of Open Access Journals (Sweden)

    Ayse Gul Kocak Altintas

    2016-02-01

    Full Text Available AIM: To evaluate the effect of phacoemulsification(phacoparameters in micropulse phaco-tecnology with chamber stabilization environment(CASEand increased control and efficiency(ICEmode on central foveal thickness(CFTchanges after uneventful cataract surgery in normal and diabetic patients without retinopathy.METHODS: In this prospective study a total of 120 patients consist of 60 patients with type 2 diabetes mellitus as a diabetic group(DGwithout retinopathy and 60 normal subjects as a control group(CGwho underwent uneventful phaco were evaluated. Intraoperative phacoemulsification parameters including phaco time(PT, and effective phaco time(EPTwere recorded. The CFT measurements were performed preoperatively, at 1 and 3mo postoperatively. The CFT differences were calculated in each exam.RESULTS:The mean PT in DG was 1.40±0.43min and it was 1.44±0.32min in CG, the difference was not significant(P=0.85. The mean EPT was 20.12±8.82s and 19.24±9.02s in DG and CG respectively which was statistically insignificant(P=0.964. The mean preoperative CFT was 218.4±12.0 μm in DG and 222.1±16.6 μm in CG which was not statistically different(P=0.168. The mean increment of CFT in DG was 30.3±37.2 μm at 1mo postoperatively, while it was 13.1±12.5 μm in CG. Even the CFT increments were significant in both groups at 1mo postoperatively, it was statistically higher in DG than that of CG(P=0.001. The average CFT increment at 3mo postoperatively comparing to preoperative level was 12.5±12.4 μm and 4.6±9.7 μm in DG and CG respectively. The increment of CFT was significantly higher in DG than that of CG(P=0.00. But the comparison of the mean CFTs changes from postoperative 1mo and 3mo in both DG and CG, significant decrements were observed in each group(P=0.00 and P=0.03 respectively.CONCLUSION: The significant increment of CFT following uneventful phaco. With the similar phaco parameters were observed in both normal and diabetic subjects. The CFT

  17. Acute Toxicity Comparison of Single-Walled Carbon Nanotubes in Various Freshwater Organisms

    Directory of Open Access Journals (Sweden)

    Eun Kyung Sohn

    2015-01-01

    Full Text Available While the commercialization of single-walled carbon nanotubes (SWCNTs is rapidly expanding, the environmental impact of this nanomaterial is not well understood. Therefore, the present study evaluates the acute aquatic toxicity of SWCNTs towards two freshwater microalgae (Raphidocelis subcapitata and Chlorella vulgaris, a microcrustacean (Daphnia magna, and a fish (Oryzias latipes based on OECD test guidelines (201, 202, and 203. According to the results, the SWCNTs inhibited the growth of the algae R. subcapitata and C. vulgaris with a median effective concentration (EC50 of 29.99 and 30.96 mg/L, respectively, representing “acute category 3” in the Globally Harmonized System (GHS of classification and labeling of chemicals. Meanwhile, the acute toxicity test using O. latipes and D. magna did not show any mortality/immobilizing effects up to a concentration of 100.00 mg/L SWCNTs, indicating no hazard category in the GHS classification. In conclusion, SWCNTs were found to induce acute ecotoxicity in freshwater microalgae, yet not in D. magna and medaka fish.

  18. [Design Method Analysis and Performance Comparison of Wall Filter for Ultrasound Color Flow Imaging].

    Science.gov (United States)

    Wang, Lutao; Xiao, Jun; Chai, Hua

    2015-08-01

    The successful suppression of clutter arising from stationary or slowly moving tissue is one of the key issues in medical ultrasound color blood imaging. Remaining clutter may cause bias in the mean blood frequency estimation and results in a potentially misleading description of blood-flow. In this paper, based on the principle of general wall-filter, the design process of three classes of filters, infinitely impulse response with projection initialization (Prj-IIR), polynomials regression (Pol-Reg), and eigen-based filters are previewed and analyzed. The performance of the filters was assessed by calculating the bias and variance of a mean blood velocity using a standard autocorrelation estimator. Simulation results show that the performance of Pol-Reg filter is similar to Prj-IIR filters. Both of them can offer accurate estimation of mean blood flow speed under steady clutter conditions, and the clutter rejection ability can be enhanced by increasing the ensemble size of Doppler vector. Eigen-based filters can effectively remove the non-stationary clutter component, and further improve the estimation accuracy for low speed blood flow signals. There is also no significant increase in computation complexity for eigen-based filters when the ensemble size is less than 10.

  19. Comparison of complex permittivities of isotonic colloids containing single-wall carbon nanotubes of varying chirality.

    Science.gov (United States)

    Nair, Tejas; Symanowski, James T; Gach, H Michael

    2012-02-01

    The application of bio-compatible, conductive nanoparticles in combination with radiofrequency (RF) irradiation to raise tissue temperatures between 40 and 60 °C for hyperthermia and ablation spurred interest in the complex permittivities of isotonic nanoparticle-based colloids. Nanoparticles with large aspect ratios and high permittivities increase the bulk permittivity of the colloid and RF losses at the macroscopic scale. The complex permittivities of isotonic colloids with and without single-wall carbon nanotubes (SWCNTs) containing either metallic, semiconducting, or mixed chiralities were measured from 20 MHz to 1 GHz at room temperature. The colloids were made with one of three different isotonic solvents: phosphate buffered saline (PBS), and Dulbecco's modified eagle medium (DMEM) with and without 0.5% weight/volume bovine serum albumin to simulate cytosol and blood, respectively. The concentration of elemental carbon from the SWCNTs in the colloids ranged from 16 to 17 mM. The permittivities were corrected for electrode polarization effects by fitting the data to the Cole-Cole relaxation model with a constant phase angle element. The presence of SWCNTs increased both the real and imaginary components of the permittivities of the colloids. For all three solvents, the direct current (DC) components of the real and imaginary permittivities were greatest for the colloids containing the mixed chirality SWCNTs, followed by the colloids with semiconducting SWCNTs, and then metallic SWCNTs. Copyright © 2011 Wiley Periodicals, Inc.

  20. Comparison of analytical techniques for purity evaluation of single-walled carbon nanotubes.

    Science.gov (United States)

    Itkis, Mikhail E; Perea, Daniel E; Jung, Richard; Niyogi, Sandip; Haddon, Robert C

    2005-03-16

    We compare popular analytical techniques, including scanning and transmission electron microscopy (SEM and TEM), thermogravimetric analysis (TGA), and Raman and near-infrared (NIR) spectroscopy, for the evaluation of the purity of bulk quantities of single-walled carbon nanotubes (SWNTs). Despite their importance as imaging techniques, SEM and TEM are not capable of quantitatively evaluating the purity of typical inhomogeneous bulk SWNT samples because the image frame visualizes less than 1 pg of SWNT material; furthermore, there is no published algorithm to convert such images into numerical data. The TGA technique is capable of measuring the amount of metal catalyst in an SWNT sample, but does not provide an unambiguous separation between the content of SWNTs and carbonaceous impurities. We discuss the utilization of solution-phase near-infrared spectroscopy and solution-phase Raman spectroscopy to quantitatively compare arbitrary samples of bulk SWNT materials of different purities. The primary goal of this paper is to provide the chemical community with a realistic evaluation of current analytical tools for the purity evaluation of a bulk sample of SWNTs. The secondary goal is to draw attention to the growing crisis in the SWNT industry as a result of the lack of quality control and the misleading advertising by suppliers of this material.

  1. Acute toxicity comparison of single-walled carbon nanotubes in various freshwater organisms.

    Science.gov (United States)

    Sohn, Eun Kyung; Chung, Young Shin; Johari, Seyed Ali; Kim, Tae Gyu; Kim, Jin Kwon; Lee, Ji Hyun; Lee, Yong Hwa; Kang, Sung Wook; Yu, Il Je

    2015-01-01

    While the commercialization of single-walled carbon nanotubes (SWCNTs) is rapidly expanding, the environmental impact of this nanomaterial is not well understood. Therefore, the present study evaluates the acute aquatic toxicity of SWCNTs towards two freshwater microalgae (Raphidocelis subcapitata and Chlorella vulgaris), a microcrustacean (Daphnia magna), and a fish (Oryzias latipes) based on OECD test guidelines (201, 202, and 203). According to the results, the SWCNTs inhibited the growth of the algae R. subcapitata and C. vulgaris with a median effective concentration (EC50) of 29.99 and 30.96 mg/L, respectively, representing "acute category 3" in the Globally Harmonized System (GHS) of classification and labeling of chemicals. Meanwhile, the acute toxicity test using O. latipes and D. magna did not show any mortality/immobilizing effects up to a concentration of 100.00 mg/L SWCNTs, indicating no hazard category in the GHS classification. In conclusion, SWCNTs were found to induce acute ecotoxicity in freshwater microalgae, yet not in D. magna and medaka fish.

  2. Comparison of different lasers in terms of thrombogenicity of the laser-treated vascular wall.

    Science.gov (United States)

    Ragimov, S E; Belyaev, A A; Vertepa, I A; Dolgov, V V; Furzikov, N P; Akchurin, R S; Repin, V S; Trubetskoy, A V

    1988-01-01

    The thrombogenic properties of the laser-treated vascular wall are reported as quantitatively assessed on the basis of 33 experiments with peripheral canine vessel segments. Three types of surfaces, namely, 1) intact, 2) mechanically de-endothelized, and 3) postlaser, have been simultaneously exposed to platelet-enriched plasma in a sequentially organized artificial circulation system. Then the adherent platelets have been counted on the treated surfaces, and the relative thrombogenicity index has been calculated according to the equation T = (A1 - Aint)/(Ad - Aint), where Aint, Ad, A1 = the adherent platelet counts on intact, mechanically de-endothelized, and laser-treated surfaces, respectively. The following lasers have been evaluated: 1) Nd-YAG, 1,060 nm, continuous wave, 4W; 2) argon-ion, 480 and 514 nm and argon-ion, 350 nm, continuous-wave, 1 W and 400 mW [corrected], respectively; 3) excimer XeCl, 308 nm, pulsed, 30 mJ per pulse, repetition rate 10 Hz [corrected]; and also 4) the laser-heated metal probe (2 mm diameter, Trimedyne, Nd-YAG) 1,060 nm, 8 W. The thrombogenicity index values obtained were 83 +/- 7, 72 +/- 8, 57 +/- 9, 63 +/- 7, and 82 +/- 9%, respectively. The differences between these values were statistically insignificant. The data are suggestive of the essential requirement of, at least, anticoagulant therapy after laser angioplasty irrespective of the laser type.

  3. Comparison of fetal toxicity of various multi-wall carbon nanotubes in mice

    Directory of Open Access Journals (Sweden)

    Tomoko Fujitani

    2015-01-01

    Full Text Available The fetal toxicities of multi-wall carbon nanotubes (MWCNTs with various sizes were compared in CD1(ICR mice. MWCNTs were suspended in 2% sodium carboxymethyl cellulose solution in phosphate-buffered saline. On day 9 of gestation, dams were administered a single intraperitoneal dose of MWCNTs (4 mg/kg body weight, while dams in the control group were administered vehicle (10 mL/kg body weight. The rectal temperatures of the dams were monitored 2 h after administaration to asses statuses of the dams. The dams and fetuses were examined on day 18 of gestation. The number of live fetus per dam decreased in some MWCNTs-administered groups. The mean percentages of live fetuses in total implantations in the MWCNTs-administered groups markedly varied from 0% to 95%, and the highest mean percentage of live fetuses in the MWCNTs-administered group was equivalent to that of the control group. The decrease in live fetuses depended on an increased number of early dead fetuses. In the groups with markedly lowered rectal temperature after administration, the fetal loss were evident. The blood levels of interleukin-6 and/or monocyte chemoattractant protein-1 in dam 2 h after administration of MWCNTs markedlyr increased, especially in the goups with significant decrease in live fetuses. These results indicated a relationship between inflammation in the dam, which probabely depended on the particular length of the MWCNTs, and the fetal toxicioty of MWCNTs in mice.

  4. Heat-Induced, Pressure-Induced and Centrifugal-Force-Induced Exact Axisymmetric Thermo-Mechanical Analyses in a Thick-Walled Spherical Vessel, an Infinite Cylindrical Vessel, and a Uniform Disk Made of an Isotropic and Homogeneous Material

    Directory of Open Access Journals (Sweden)

    Vebil Yıldırım

    2017-07-01

    Full Text Available Heat-induced, pressure-induced, and centrifugal force-induced axisymmetric exact deformation and stresses in a thick-walled spherical vessel, a cylindrical vessel, and a uniform disk are all determined analytically at a specified constant surface temperature and at a constant angular velocity. The inner and outer pressures are both included in the formulation of annular structures made of an isotropic and homogeneous linear elastic material. Governing equations in the form of Euler-Cauchy differential equation with constant coefficients are solved and results are presented in compact forms. For disks, three different boundary conditions are taken into account to consider mechanical engineering applications. The present study is also peppered with numerical results in graphical forms.

  5. Calculation of the thicknesses of the walls of the radiographic inspection building of the NKS enterprise; Calculo de los espesores de los muros del edificio de inspeccion radiografica de la empresa NKS

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez A, G.; Gutierrez R, C

    1983-07-15

    During the month of February, 1983, the Structural Civil Department of the Latin American of Engineering, S.A. de C.V. company (LATISA), outline to the Engineering and Industry Applications Management of the ININ that the industrial group NKS had taken charge them the design of a building where it would lodge a linear electron accelerator of 4 MeV, one source of Co-60 of 30 Ci and an X-ray equipment, tube type, of range of 60 to 300 KV and that to make the design they required to know the necessary thickness of the walls, doors and roof to protect to the workers, outside of the building, of the X and gamma radiations generated by the sources mentioned during the radiographic inspections of metal-mechanical pieces. (Author)

  6. 厚壁压力容器近表面 TOFD 检测研究%Research on TOFD Detection of the Near-surface of Thick-walled Pressure Vessel

    Institute of Scientific and Technical Information of China (English)

    刘畅; 张国福

    2015-01-01

    From perspective of thick-walled pressure vessel near-surface defect detection rate and accuracy of defect size positioning and quantifying,upper tier detection experiment on 205mm thick-walled test block was carried out by using time of flight diffraction (TOFD) technology. The reliability of methods of changing probe centre separation and angle of incidence to decrease the dead zone in the upper surface was verified combined with whole-body imaging result of the upper tier. The experimental result shows that TOFD has strong ability to independently detect the defect in the upper surface dead zone, but it can not accurately determine flaw depth and height. However combined with the phased array technique, its near-surface detection effect can be effectively improved.%从厚壁压力容器近表面缺陷的检出率和缺陷尺寸定位定量的精准性角度出发,开展205 mm 厚壁试块超声波衍射时差法(TOFD)上分区检测实验,结合上分区的整体成像结果,验证理论计算得出的通过改变探头间距和入射角来减小上表面盲区的方法是否可靠。实验结果表明,TOFD 具有很强的独立发现上表面盲区内缺陷的能力,但无法获得缺陷自身深度和高度的精确定量,结合相控阵技术则可以有效提高近表面检测效果。

  7. Comparison of central corneal thickness measured by hand-held and desk-mounted ultrasound pachymeters in glaucoma patients.

    Science.gov (United States)

    Salim, Sarwat; Du, Haiming; Wan, Jim

    2015-07-01

    The purpose of this study was to compare the accuracy and reproducibility of central corneal thickness measured by hand-held and desk-mounted ultrasound pachymeter in glaucoma patients under treatment. Prospective study of 65 glaucoma patients. Central corneal thickness was measured by two ultrasound pachymeters: the hand-held, portable PachPen (Accutome, Lynwood, WA), and the desk-mounted PacScan 300 (Sonomed, Lake Success, NY). The mean ± SD central corneal thickness was 526.5 ± 44.8 µm and 530.0 ± 44.7 µm for the hand-held and desk-mounted pachymeters, respectively (p = 0.15). Linear regression analysis revealed a slope of 0.97 with Pearson correlation coefficient of 0.96. Bland-Altman analysis showed a mean difference of measurements by both pachymeters of 3.22 µm with two standard deviations = 9.51. Both instruments showed high intraobserver correlation: 0.972 for the hand-held pachymeter and 0.993 for the desk-mounted pachymeter. Central corneal thickness measurements were comparable with the use of hand-held and desk-mounted ultrasound units in glaucoma patients with good intraobserver reproducibility.

  8. Development of automated welding processes for field fabrication of thick-walled pressure vessels: electron beam method. Fourth quarterly report, July 1--September 30, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.M.

    1978-01-01

    This report is the fourth quarterly report of a project to develop and demonstrate an electron beam welding procedure for welding 8'' thick SA 387 Grade 22 Class 2 (2-1/4 Cr--1 Mo) steel. Due to the late arrival of the steel to be used in this project, a six month extension in the completion date has been made. Work is in progress for developing 4-1/2'' deep partial penetration electron beam welding procedures. A total of 257 welds have been made to date. Several defects have been encountered and successfully eliminated. The occurrence of a necklace defect, which has been shown to be a cold shut resulting from improper solidification, has not yet been eliminated. It has been observed that the beam oscillation pattern is influential on the behavior of the weld cavity during welding. In the vertical welding position, it has been determined that the use of a welding shoe is required.

  9. 下颌第二恒磨牙C型根根管壁厚度的显微CT分析%A micro-CT analysis of the wall thickness of C-shaped canals in permanent mandibular second molars

    Institute of Scientific and Technical Information of China (English)

    顾永春; 朱琦; 张燕萍; 周培刚; 丁月峰; 陈花花; 周涛

    2014-01-01

    Objective:To analyze the wall thickness of C-shaped canals in permanent mandibular second molars.Methods:40 ex-tracted permanent mandibular second molars with C-shaped root were collected from native Chinese and were scanned by micro-CT scan-ner.The specimens were reconstructed three-dimensionally by software Mimics 10.01.The roots were sliced from cemento-enamel junc-tion (CEJ)to apex with 1 mm intervals.The cross-sectional root canal configurations were classified into 5 types according to the Fan's Classification.The minimum buccal wall thickness (MBWT),minimum lingual wall thickness(MLWT)and their locations,as well as the wall thickness at the mesial and distal reference sites were detected.Two-way ANOVA and post hoc LSD-t tests were used to com-pare the mean thickness at 4 sides.Results:Among 370 cross-sections of 40 C-shaped roots,C1,C2 and C3 canals were observed on 126(34.1%),46 (12.4%)and 160 (43.2%)sections respectively.Except at the 10 mm level,the mean MLWT was always lower than MBWT;and the MLWT and MBWT were always lower than the wall thickness at the mesial and distal reference sites.The differ-ence was statistically significant (P <0.05)along the root length above the 12 mm level.The MBWT of the C2 and C3 canals was more likely located at the mesial region,and the MBWT of the C1 and the MLWT of C1,C2 and C3 was more frequently located at the center region.Conclusion:The lingual wall of C-shaped canal in mandibualr second molars was the thinnest zone among four sides,and care should be taken during root canal instrumentation and post space preparation to avoid perforation.%目的:测量下颌第二恒磨牙 C 型根的根管壁厚度。方法:采集到中国汉族患者拔除的 C 形根下颌第二恒磨牙40颗。显微 CT 扫描后采用 Mimics 10.01软件进行三维重建;沿着牙体长轴从釉牙骨质界(CEJ)到根尖顶每隔1 mm 连续虚拟横切牙根模型,观测牙根横截面上 C 形根管的类型(范兵分型)

  10. Prediction of UHPFRC panels thickness subjected to aircraft engine impact

    Directory of Open Access Journals (Sweden)

    Duc-Kien Thai

    2016-06-01

    Full Text Available 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 wall caused by the impact of aircraft engine missile is investigated using a finite element program LS-DYNA. The structural components of the UHPFRC panel, aircraft engine model, and their contacts are fully modeled. The analysis results are verified with the test results. A parametric study with varying panel thickness, fiber type and content, and impact velocity is performed to investigate the local damage of the UHPFRC panel. Based on a comparison with the given formulas, the modified equations of Chang and Degen are proposed to predict the minimum wall thickness to prevent scabbing and perforation in the case in which the UHPFRC structure is used.

  11. Analysis on heat storage layer and thickness of soil wall in solar greenhouse based on theory of temperature-wave transfer%基于温波传递理论的日光温室土墙体蓄热层及墙体厚度分析

    Institute of Scientific and Technical Information of China (English)

    白青; 张亚红; 孙利鑫

    2016-01-01

    The wall plays an important role in the study of the greenhouse. Heat storage layer and thickness of the wall are 2 key factors for studying wall thermal environment and optimizing the structure. As widely used wall in solar greenhouse, soil wall is typical and representative, and it is significant to study heat storage layer and thickness of soil wall. To study the varying rule of the heat storage layer and to find the optimum thickness of the wall, an experiment was performed in Yanghe County, Yinchuan, Ningxia, China in 2011. The fifth generation greenhouse with soil wall from Shouguang City, Shandong Province was used. The CR10X-2M and CR3000 data collectors from America were adopted, and 18 T-types thermocouple temperature probes were also used to test inner wall temperature at the positions of 0, 10, 20, 30, 40, 50, 60, 80, 100, 150, 200, 230, 250, 280 and 330 cm thickness (along horizontal direction of wall body). The temperature variation was analyzed in the horizontal direction. Indoor temperature and wall temperature were used to determine the thickness of heat storage layer. Besides, a method for calculating wall thickness was pointed out, which was based on wall temperature spreading speed. The results showed with the increase of wall depth, the variation of bilateral temperature-wave of the wall became less obvious. However, the temperatures were gradually decreased from wall surface to exterior surface. Temperature-wave amplitude approached zero at 50-230 cm depth of the wall surface, which was in a stable state. The thickness of heat storage layer was got by using the lowest temperature of inner greenhouse and inner wall. The temperature changed obviously in 0-50 cm and 280-330 cm depth of the wall, which showed wave layer, stable layer and insulation layer existing in the north wall of solar greenhouse, and the thickness of heat storage layer was various. In January, the amplitude of temperature within a month at wave layer ranged from 10.01 to 0

  12. A Comparison of the Deep Cervical Flexor Muscle Thicknesses in Subjects with and without Neck Pain during Craniocervical Flexion Exercises.

    Science.gov (United States)

    Jun, Ilsub; Kim, Kyoung

    2013-11-01

    [Purpose] The purpose of the present study was to examine the amount of change in the thicknesses of the deep cervical flexor (DCF) and sternocleidomastoid (SCM) muscles in subjects with neck pain and subjects without neck pain during craniocervical flexion exercise (CCFE). [Subjects] The total number of subjects was 40, comprising 20 in the no-pain group (males 11, females 9) and 20 in the pain group (males 8, females 12). [Methods] Muscle images were obtained using ultrasound, and the thicknesses of the individual muscles were measured using the NIH ImageJ software. [Results] During CCFE, as pressure increased, the no-pain group recruited the DCF more than the pain group, while the pain group recruited the SCM more. [Conclusion] Selective DCF contraction exercises are considered very useful in the treatment of patients with neck pain.

  13. Do different spectral domain OCT hardwares measure the same? Comparison of retinal thickness using third-party software

    DEFF Research Database (Denmark)

    Sander, Birgit; Ahmad Al-Abiji, Hajer; Kofod, Mads

    2015-01-01

    ,or if they are caused by the segmentation algorithms. Methods Thirty-seven healthy eyes were examined within the same session with a Cirrus OCT and a Spectralis OCT, the latter using averaged B-scans. Scans from similar positions and passing the fovea were analyzed by custom-made software. Thickness was analyzed...... at the fovea, the central 1-mmline and the 6-mm line. Results When Cirrus and Spectralis scans were analyzed with the same software, the retinal thickness at the foveal center was 225.92 μm (SD 17.0) using the Cirrus and 228.70 μm(SD 18.4) using the Spectralis; the difference of 2.78 μm wasnot significant (p=0...... did Cirrus, with a mean of3.32 μm (psoftware of the instruments, and by less than 3 μm when analyzed with the same custom-made software, indicating that the major...

  14. Comparison of Two Cap Thickness in Small Incision Lenticule Extraction: 100μm versus 160μm.

    Science.gov (United States)

    He, Miao; Wang, Wei; Ding, Hui; Zhong, Xingwu

    To compare the changes of biomechanical properties, endothelial cell density (ECD), and posterior corneal elevation (PCE) after femtosecond small incision lenticule extractions (SMILEs) with 100μm versus 160μm cap thicknesses. A total of 12 rabbits were randomly assigned into two groups of 6 each. SMILE was performed at a depth of either 160μm (160-cap group) or 100μm (100-cap group). Corneal biomechanics, PCE, ECD were evaluated pre-operatively, 1week, 1 month, 2 months, 3 months, and 4 months post-operatively by Pentacam, Corvis ST, in vivo confocal microscopy (IVCM) respectively. The Young's modulus was obtained by strip-extensometry test 4 months after surgery. At each time point, the second applanation time (A2T) was similar between the groups with the exception of 4 months after surgery (22.66±0.16 ms in the 160-cap group versus 21.75±0.29 ms in the 100-cap group, p = 0.004). Neither deformation amplitude (DA) nor the first applanationtime (A1T) were significantly different between the two groups. The postoperative posterior surface did not shift forward, the changes of PCE and ECD were not significantly different between the two groups at any observation time. Young's modulus was higher in the 160-cap group than that in the 100-cap group with no statistical significance (P>0.05). Regression analyses showed that the PCE changes and Young's modulus were not affected by cap thickness (CT) or residual stromal bed thickness (RBT) (All P>0.05). The differences of corneal biomechanics, posterior surface elevation, or ECD changes were quite small when using 100μm or 160μm cap thicknesses in SMILE.

  15. Body fat measurement in adolescents: comparison of skinfold thickness equations with dual-energy X-ray absorptiometry.

    Science.gov (United States)

    Rodríguez, G; Moreno, L A; Blay, M G; Blay, V A; Fleta, J; Sarría, A; Bueno, M

    2005-10-01

    To compare the most commonly used equations to predict body fatness from skinfold thickness, in male and female adolescents, with dual-energy X-ray absorptiometry (DXA) as a reference method of fatness measurement. Cross-sectional nutrition survey. General adolescent population from Zaragoza (Spain). A total of 238 Caucasian adolescents (167 females and 113 males), aged 13.0-17.9 y, were recruited from 15 school groups in 11 public and private schools. The percentage fat mass (%FM) was calculated by using skinfold-thickness equations. Predicted %FM was compared with the reference %FM values, measured by DXA. The lack of agreement between methods was assessed by calculating the bias and its 95% limits of agreement. Most equations did not demonstrate good agreement compared with DXA. However, in male adolescents, Slaughter et al equations showed relative biases that were not dependent on body fatness and the limits of agreement were narrower than those obtained from the rest of equations. In females, Brook's equation showed nonsignificant differences against DXA and the narrowest 95% limits of agreement. Only biases from Brook and Slaughter et al equations were not dependent on body fatness in female adolescents. Accuracy of most of the skinfold-thickness equations for assessment of %FM in adolescents was poor at the individual level. Nevertheless, to predict %FM when a relative index of fatness is required in field or clinical studies, Slaughter et al equations may be used in adolescents from both sexes and the Brook equation in female adolescents.

  16. Dose comparison according to Smooth Thickness application of Range compensator during proton therapy for brain tumor patient

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tase Woan; Kim, Dae Woong; Kim, Jae Weon; Jeong, Kyeong Sik [Proton Therapy Center, National Cancer Center, Goyang (Korea, Republic of)

    2016-12-15

    Range Compensator used for proton therapy compensates the proton beam dose which delivers to the normal tissues according to the Target's Distal Margin dose. We are going to check the improvement of dose on the target part by comparing the dose of PTV and OAR according to applying in different method of Smooth Thickness of Range Compensator which is used in brain tumor therapy. For 10 brain tumor patients taking proton therapy in National Cancer Center, Apply Smooth Thickness applied in Range Compensator in order from one to five by using Compensator Editor of Eclipse Proton Planning System(Version 10.0, Varian, USA). The therapy plan algorithm used Proton Convolution Superposition(version 8.1.20 or 10.0.28), and we compared Dmax, Dmin, Homogeneity Index, Conformity Index and OAR dose around tumor by applying Smooth Thickness in phase. When Smooth Thickness was applied from one to five, the Dmax of PTV was decreased max 4.3%, minimum at 0.8 and average of 1.81%. Dmin increased max 1.8%, min 1.8% and average. Difference between max dose and minimum dose decreased at max 5.9% min 1.4% and average 2.6%. Homogeneity Index decreased average of 0.018 and Conformity Index didn't had a meaningful change. OAR dose decreased in Brain Stem at max 1.6%, min 0.1% and average 0.6% and in Optic Chiasm max 1.3%, min 0.3%, and average 0.5%. However, patient C and patient E had an increase each 0.3% and 0.6%. Additionally, in Rt. Optic Nerve, there was a decrease at max 1.5%, min 0.3%, and average 0.8%, however, patient B had 0.1% increase. In Lt. Optic Nerve, there was a decrease at max 1.8%, min 0.3%, and average 0.7%, however, patient H had 0.4 increase. As Smooth Thickness of Range Compensator which is used as the proton treatment for brain tumor patients is applied in stages, the resolution of Compensator increased and as a result the most optimized amount of proton beam dose can be delivered. This is considered to be able to irradiate the equal amount at PTV and

  17. Thin Wall Iron Castings

    Energy Technology Data Exchange (ETDEWEB)

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  18. 深埋黏土层冻结壁厚度的有限段高计算模型研究%Research on finite-length computational model of deep-buried frozen soil wall thickness

    Institute of Scientific and Technical Information of China (English)

    黄俐; 宋常军

    2016-01-01

    冻结壁设计理论关系到冻结法施工的成败,常规的弹塑性力学冻结壁厚度模型已不适用于深厚冲积层中冻结壁的设计。考虑卸载状态下冻结壁-周围未冻土的共同作用,基于三向应力状态下的冻土流变理论及偏张量虎克定律,建立了深埋黏土层有限段高冻结壁的变形及厚度计算模型。结合立井冻结工程,探讨了该计算模型对不同开挖因素的响应程度。结果表明:合理的降低段高、控制施工速度对冻结法凿井安全至关重要。该计算模型对深埋黏土层冻结壁设计有重要的理论意义。%As the design theory of frozen wall is the key of artificially ground freezing construction, and the conventional elastic-plastic mechanical models are not suitable for frozen wall design in deep alluvium. Considering the effect of excavation length and the interaction between frozen soil wall and its surrounding earth mass, the calculation models of deformation and thickness of finite-length frozen soil wall are developed based on the rheological theory of frozen soil and Hooke′s law of deviatoric tensor of equivalent stress-equivalent strain under tri-axial stress state. Combined with a shaft freezing engineering case, the influences of excavation length and duration of exposure on the calculation models are discussed. The results show that reducing the excavation section appropriately and controlling the construction speed reasonable is crucial to the safety of artificial freezing shaft sinking project.

  19. 大口径厚壁钢管热模法离心铸造机的设计与应用%Design and Application of A Centrifugal Casting Machine with Hot Die for Large Caliber Steel Pipt with Thick Wall

    Institute of Scientific and Technical Information of China (English)

    习杰

    2011-01-01

    详细介绍了采用热模法离心铸造厚壁钢管坯的设计思路,以及该机主要机构(等量浇注装置、主机、推管机构等)的设计.%Design idea of a centrifugal casting machine with hot die for large caliber steel pipt with thick wall has been introduced in details with design of the main equipment such as pouring device with dosing device, main machine and pipe ejector etc., hence a typical instance of application of centrifugal casting technology on forming of pipe with thick wall.

  20. Dosimetric comparisons of carbon ion treatment plans for 1D and 2D ripple filters with variable thicknesses

    Science.gov (United States)

    Printz Ringbæk, Toke; Weber, Uli; Santiago, Alina; Simeonov, Yuri; Fritz, Peter; Krämer, Michael; Wittig, Andrea; Bassler, Niels; Engenhart-Cabillic, Rita; Zink, Klemens

    2016-06-01

    A ripple filter (RiFi)—also called mini-ridge filter—is a passive energy modulator used in particle beam treatments that broadens the Bragg peak (BP) as a function of its maximum thickness. The number of different energies requested from the accelerator can thus be reduced, which significantly reduces the treatment time. A new second generation RiFi with 2D groove shapes was developed using rapid prototyping, which optimizes the beam-modulating material and enables RiFi thicknesses of up to 6 mm. Carbon ion treatment plans were calculated using the standard 1D 3 mm thick RiFi and the new 4 and 6 mm 2D RiFis for spherical planning target volumes (PTVs) in water, eight stage I non-small cell lung cancer cases, four skull base chordoma cases and three prostate cancer cases. TRiP98 was used for treatment planning with facility-specific base data calculated with the Monte Carlo code SHIELD-HIT12A. Dose-volume-histograms, spatial dose distributions and dosimetric indexes were used for plan evaluation. Plan homogeneity and conformity of thinner RiFis were slightly superior to thicker RiFis but satisfactory results were obtained for all RiFis investigated. For the 6 mm RiFi, fine structures in the dose distribution caused by the larger energy steps were observed at the PTV edges, in particular for superficial and/or very small PTVs but performances for all RiFis increased with penetration depth due to straggling and scattering effects. Plans with the new RiFi design yielded for the studied cases comparable dosimetric results to the standard RiFi while the 4 and 6 mm RiFis lowered the irradiation time by 25-30% and 45-49%, respectively.

  1. Dosimetric comparisons of carbon ion treatment plans for 1D and 2D ripple filters with variable thicknesses.

    Science.gov (United States)

    Ringbæk, Toke Printz; Weber, Uli; Santiago, Alina; Simeonov, Yuri; Fritz, Peter; Krämer, Michael; Wittig, Andrea; Bassler, Niels; Engenhart-Cabillic, Rita; Zink, Klemens

    2016-06-01

    A ripple filter (RiFi)-also called mini-ridge filter-is a passive energy modulator used in particle beam treatments that broadens the Bragg peak (BP) as a function of its maximum thickness. The number of different energies requested from the accelerator can thus be reduced, which significantly reduces the treatment time. A new second generation RiFi with 2D groove shapes was developed using rapid prototyping, which optimizes the beam-modulating material and enables RiFi thicknesses of up to 6 mm. Carbon ion treatment plans were calculated using the standard 1D 3 mm thick RiFi and the new 4 and 6 mm 2D RiFis for spherical planning target volumes (PTVs) in water, eight stage I non-small cell lung cancer cases, four skull base chordoma cases and three prostate cancer cases. TRiP98 was used for treatment planning with facility-specific base data calculated with the Monte Carlo code SHIELD-HIT12A. Dose-volume-histograms, spatial dose distributions and dosimetric indexes were used for plan evaluation. Plan homogeneity and conformity of thinner RiFis were slightly superior to thicker RiFis but satisfactory results were obtained for all RiFis investigated. For the 6 mm RiFi, fine structures in the dose distribution caused by the larger energy steps were observed at the PTV edges, in particular for superficial and/or very small PTVs but performances for all RiFis increased with penetration depth due to straggling and scattering effects. Plans with the new RiFi design yielded for the studied cases comparable dosimetric results to the standard RiFi while the 4 and 6 mm RiFis lowered the irradiation time by 25-30% and 45-49%, respectively.

  2. A Comparison of Vibroacoustic Response of Isotropic Plate with Attached Discrete Patches and Point Masses Having Different Thickness Variation with Different Taper Ratios

    Directory of Open Access Journals (Sweden)

    Bipin Kumar

    2016-01-01

    Full Text Available A comparison of sound radiation behavior of plate in air medium with attached discrete patches/point masses having different thickness variations with different taper ratio of 0.3, 0.6, and 0.9 is analysed. Finite element method is used to find the vibration characteristics while Rayleigh integral is used to predict the sound radiation characteristics. Minimum peak sound power level obtained is at a taper ratio of 0.6 with parabolic increasing-decreasing thickness variation for plate with four discrete patches. At higher taper ratio, linearly increasing-decreasing thickness variation is another alternative for minimum peak sound power level suppression with discrete patches. It is found that, in low frequency range, average radiation efficiency remains almost the same, but near first peak, four patches or four point masses cause increase in average radiation efficiency; that is, redistribution of point masses/patches does have effect on average radiation efficiency at a given taper ratio.

  3. 开口冷弯厚壁型钢轴压构件抗震性能研究%Research on the seismic behaviors of opening cold-formed thick-walled steel under the axial cyclic loading

    Institute of Scientific and Technical Information of China (English)

    付小超; 李元齐; 沈祖炎

    2016-01-01

    为研究开口冷弯厚壁型钢构件在轴向滞回荷载作用下的抗震性能,首先选取了3根壁厚t>6 mm的冷弯内卷边槽钢进行轴向滞回试验,然后建立相关的ANSYS有限元模型进行模拟计算,在与试验结果对比的基础上,选取了不同的腹板宽厚比(h/t=25~90)、绕弱轴长细比(λy=30~90)的构件进行参数化分析计算.研究结果表明:宽厚比、长细比是影响冷弯型钢抗震性能的两个主要因素,宽厚比(h/t)越大抗震性能越差,长细比(λy)越大抗震性能同样也越差,设计时应尽量避免选择长细比和宽厚比均较大的构件.%In order to investigate the hysteretic behaviors of opening cold-formed thick-walled steel members under the axial cyclic loading, three cold-formed steel columns were tested. On the basis of compared with the test results, a finite element method ( FEM) in ANSYS was established. The in-fluence of width-thickness ratio ( h/t) rang from 25 to 90 for web and slenderness ratio about the weak axis y (λy ) rang from 30 to 90 of such members were investigated by FEM. Analysis results in-dicated that the width-thickness ratio and the slenderness ratio about the weak axis y are the most important factors to affect the hysteretic behaviors. So, the cold-formed steels which with great width-thickness ratio ( h/t) and great slenderness ratio (λy ) should be avoided in designing, because they will lead to poor seismic performance.

  4. Thick Tori around Active Galactic Nuclei - a Comparison of Model Predictions with Observations of the Infrared Continuum and Silicate Features

    Science.gov (United States)

    Granato, G. L.; Danese, L.

    1994-05-01

    The continuum expected from active galactic nuclei (AGN) surrounded by thick tori is compared to the data available for a sample of optically selected Seyfert 1 galaxies. The optical and near-IR nuclear fluxes have previously been derived for these objects, and hence the spectral energy distributions (SEDs) of their active nuclei can be analysed. We perform detailed calculations of the 0.1 to 1000 micron SEDs for AGN surrounded by dust tori with different opening angles. The dust mixture is mimicked by using three silicate and three graphite grains of different sizes. The radiative transfer equation for a cloud having azimuthal symmetry and containing a mixture of dust grains is solved by means of a numerical code that takes absorption, emission and scattering into account. We discuss the optimization of the free parameters by comparing the spectra predicted by the code to available data. The general absence of the silicate emission feature at about 10 microns in the spectra of broad- line AGN and the general presence of the 10 micron silicate absorption feature in narrow-line AGN are addressed. The ensuing constraints are discussed. We show that models of thick tori extending up to a few hundred parsecs in which physical processes such as shocks significantly reduce the silicate grain abundance within the first few tens of parsecs are fully consistent with available broad-band data and high-resolution IR spectra of Seyfert 1 and 2 nuclei.

  5. The retinal nerve fibre layer thickness in glaucomatous hydrophthalmic eyes assessed by scanning laser polarimetry with variable corneal compensation in comparison with age-matched healthy children.

    Science.gov (United States)

    Hložánek, Martin; Ošmera, Jakub; Ležatková, Pavlína; Sedláčková, Petra; Filouš, Aleš

    2012-12-01

    To compare the thickness of the retinal nerve fibre layer (RNFL) in hydrophthalmic glaucomatous eyes in children with age-matched healthy controls using scanning laser polarimetry with variable corneal compensation (GDxVCC). Twenty hydrophthalmic eyes of 20 patients with the mean age of 10.64 ± 3.02 years being treated for congenital or infantile glaucoma were included in the analysis. Evaluation of RNFL thickness measured by GDxVCC in standard Temporal-Superior-Nasal-Inferior-Temporal (TSNIT) parameters was performed. The results were compared to TSNIT values of an age-matched control group of 120 healthy children published recently as referential values. The correlation between horizontal corneal diameter and RNFL thickness in hydrophthalmic eyes was also investigated. The mean ± SD values in TSNIT Average, Superior Average, Inferior Average and TSNIT SD in hydrophthalmic eyes were 52.3 ± 11.4, 59.7 ± 17.1, 62.0 ± 15.6 and 20.0 ± 7.8 μm, respectively. All these values were significantly lower compared to referential TSNIT parameters of age-matched healthy eyes (p = 0.021, p = 0.001, p = 0.003 and p = 0.018, respectively). A substantial number of hydrophthalmic eyes laid below the level of 5% probability of normality in respective TSNIT parameters: 30% of the eyes in TSNIT average, 50% of the eyes in superior average, 30% of the eyes in inferior average and 45% of the eyes in TSNIT SD. No significant correlation between enlarged corneal diameter and RNFL thickness was found. The mean values of all standard TSNIT parameters assessed using GDxVCC in hydrophthalmic glaucomatous eyes in children were significantly lower in comparison with referential values of healthy age-matched children. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

  6. Design of reinforced concrete walls casted in place for the maximum normal stress of compression

    Directory of Open Access Journals (Sweden)

    T. C. Braguim

    Full Text Available It is important to evaluate which designing models are safe and appropriate to structural analysis of buildings constructed in Concrete Wall system. In this work it is evaluated, through comparison of maximum normal stress of compression, a simple numerical model, which represents the walls with frame elements, with another much more robust and refined, which represents the walls with shells elements. The designing of the normal stress of compression it is done for both cases, based on NBR 16055, to conclude if the wall thickness initially adopted, it is enough or not.

  7. A New Method for Calculating Plastic Radius of Swage Autofrettage Thick-walled Cylinder%一种新的机械自紧厚壁圆筒塑性半径计算方法

    Institute of Scientific and Technical Information of China (English)

    常列珍; 潘玉田; 马新谋

    2011-01-01

    为推导一种新的机械自紧厚壁圆筒塑性半径的计算公式,首先采用ANSYS对不同摩擦系数的机械自紧进行数值模拟,发现摩擦系数对残余应力和塑性半径无影响,因此在推导塑性半径计算公式时可不考虑摩擦系数的影响;其次根据机械自紧过程中冲头圆柱段和厚壁圆筒接触处径向应力相等推导出了塑性半径的计算公式.利用该公式计算了9个不同模拟管的塑性半径,结果表明理论值与实验值吻合良好.该公式可根据过盈量求出塑性半径和自紧度,或者在已知自紧度的情况下确定过盈量.%To derive a new formula to calculate the plastic radius of autofrettaged thick-walled cylinder, some simulations were run for different friction coefficients. It was found that the friction coefficient did not influence the residual stress and plastic radius. Thus, it is unnecessary to consider the effect of the friction coefficient in deriving the new formula of plastic radius. Also, considered that the radial stress in contact section of swage and thick-walled cylinder are equal during the swage procedure, the formula of plastic radius was derived. By using the formula, the plastic radius of nine different tubes were calculated. It is shown that the theoretical values of plastic radius coincide with the experiment results better. This formula can be used to calculate the plastic radius and over strain according to the excess, or determine the excess according to the overstrain.

  8. 大型厚壁封头热锻成形中降低成型载荷的策略%Strategy of Decreasing Forming Load in Hot Forging of Heavy Thick-wall Sealing Head

    Institute of Scientific and Technical Information of China (English)

    徐戊矫; 丁永峰; 邹明平; 王凯庆

    2011-01-01

    The forging process for the heavy thick-wall saling head is required to neet the severe condition,whereas the forging factories often face eith the insufficient forging capacity to execute the foring process. Based on the rigid-viscoplastic FEM platform DEFORM-3D, the upper anvil swaging foring process was simulatde to ana1yze the cause of the fold defer and much higher forming load. The configuration of the upper anvil was optimized in the shape of saddle,meanwhile, the reduction of per revolution was deternined as 100 mm and the rotary anglc of per reduction of the upper anvil was decided as 24°. The optimized process was numerically simulated The results show that the forming load to execute the forging process is decreased to available range and the fold is avoided in the finished forgings The research is very helpful to improve the feasibility of forging proccss and forming quality of heavy thick-wall sealing head.%大型厚壁封头严苛的使用性能要求其采用整体锻造方法生产,但锻造企业通常不具备足够的设备能力以满足封头整体锻造超高的力能需求.基于刚粘塑性有限元模拟平台DEFORM-3D,对大型厚壁封头上砧旋转锻造成形原有的工艺方案进行了模拟仿真,分析了产生折迭缺陷和锻造载荷超限的原因.优化上砧形状为马鞍型,并确定上砧的运动轨迹为单周压下量为100mm,每压下一次后上砧旋转角度为24°.对优化后的工艺方案进行仿真计算.结果表明,工艺优化有效地将所需的成形载荷降到了设备能力允许的范围之内,并使整体锻造的封头无折迭缺陷.研究结果对提高封头整体锻造的可行性及改善大型厚壁封头的成形质量具有重要的指导意义.

  9. X70M大壁厚螺旋埋弧焊管丁字焊缝工艺性能研究%Investigation on the Technological Properties of X70M Thick Wall SAWH Pipe T-shape Weld

    Institute of Scientific and Technical Information of China (English)

    蒋永峰; 王伟; 冯宗泽; 陆建刚; 任超

    2016-01-01

    X70M大壁厚螺旋埋弧焊管丁字焊缝焊接接头强度过高,经过成型器反变形易产生层状撕裂,焊缝热影响区温度过高易使焊缝组织产生脆化现象,为了确保X70M大壁厚螺旋埋弧焊管丁字焊缝焊接接头的各项性能指标,采用H08D焊丝与SJ101G焊剂匹配进行工艺试验,焊接过程中严格控制层间温度、减小焊接热输入及焊后热处理形式,通过试验得出了合理的焊接工艺。试验结果表明,按该工艺所焊试件的各项性能指标均达到API SPEC 5L PSL2标准及客户技术条件,采用此工艺已成功地生产了数万吨尼日利亚输油管线用管,效果良好。%If the welded joint strength of X70M thick wall SAWH pipe is too high, it is easy to generate backward deformation and lamellar tearing when pass through the forming machine, embrittlement phenomenon easily happen caused by too high HAZ temperature. In order to ensure the performance index of X70M thick wall SAWH pipe T-shape weld welded joints, using H08D welding wire matching with SJ101G flux to carry out process test, during the welding process strictly controlled interpass temperature, reduced the welding heat input and the form of heat treatment after welding, the reasonable welding process was obtained through experiments. The test result showed that all performance indexes of specimen by adopting the above process reach the standard API SPEC 5L PSL2 and customer technical conditions, it successfully produced tens of thousands of oil pipeline in Nigeria by adopting this technology, and the effect is good.

  10. 厚壁圆筒悬臂梁模糊PID振动控制仿真%Simulation of Fuzzy PID Control Used in Vibration of the Thick Wall Cylinder Cantilever Beam

    Institute of Scientific and Technical Information of China (English)

    孙海涛; 郭保全; 张延平; 柴刚

    2016-01-01

    针对厚壁圆筒悬臂梁的振动情况进行了分析和振动控制系统仿真,旨在为火炮身管振动控制研究提供理论指导。首先运用模态分析法对悬臂梁结构进行振动动力学分析,并建立了传感方程和压电作动方程。根据模糊控制理论,以压电传感器的输出电压V(t)和V(t)的变化率Vc(t)作为模糊PID控制器的输入变量,利用模糊控制规则在线对PID参数进行整定。通过Simulink建立了基于模糊PID控制器的悬臂梁振动控制模型,继而进行仿真。仿真结果表明,基于压电材料的模糊PID控制方法对厚壁圆筒悬臂梁的振动抑制作用非常有效。%In order to provide theoretical guidance for the study of the cannon gun tube vibration control, this paper analyzes the vibration of the thick wall cylinder cantilever beam and the simulation of vibration control system. Firstly, modal analysis is carried out on the cantilever beam structure vibration dynamics analysis, and the sensing equation and piezoelectric actuator equation is established. According to the theory of fuzzy control, with piezoelectric sensor output voltageV(t) andVc(t) which is the rate of change ofV(t) as the input variable of fuzzy PID controller, we set the PID parameter online through the fuzzy control rule. The dynamic control model based on the fuzzy PID controller is established based on Simulink. The sim-ulation results show that the method of the fuzzy PID controller based on the piezoelectric material is very effective when it is used in the suppression of the vibration of the thick wall cylinder cantilever beam.

  11. A comparison of two methods to measure choroidal thickness by enhanced depth imaging optical coherence tomography -Letter to the Editor

    DEFF Research Database (Denmark)

    Lundberg, Kristian; Vergmann, Anna Stage; Vestergaard, Anders Højslet;

    2016-01-01

    -domain optical coherence tomography (EDI-SD OCT) has made it possible to visualize the choroid, and it is generally accepted that Heidelberg Spectralis OCT provides valid measurements of choroidal thickness (CT) (Li et al. 2014), although no fully automated software is commercially available. In the literature...... different approaches and software programs are described for manual measurement of the CT. Unfortunately many investigators do not report in details which method they use. Two methods for CT-measurement are available in the Heidelberg software, but to our knowledge these methods have not been compared....... Hence, the purpose of this study was to evaluate and validate the Segmentation method and the Ruler method for CT-measurement. We obtained data from 10 healthy subjects, aged 15 to 17 years (mean 16.3) and 10 patients with macular pathology, aged 59 to 79 years (mean 71.8). The diseases included wet age...

  12. The validation and comparison of the GOCI aerosol optical thickness products: a case study of Tianjin 8.12

    Science.gov (United States)

    Yao, Lingling; Zhang, Xiaoyu; Yu, Hui; Jiang, Binbin

    2016-01-01

    COMSGOCI (Geostationary Ocean Color Imager) is the first geostationary ocean color satellite in the world launched by South Korea in June 2010, which includes eight bands from the visible to the infrared band. GOCI aerosol optical thickness (AOT) at 555nm was retrieved by atmospheric radiative transfer model based on two-stream approximation algorithm. Due to GOCI without near infrared band and has a high solar elevation angle, solar zenith angle must be recalibrated to solve the earth system albedo, and the surface reflectance solved by quack atmospheric correction and recalculated backward scatter coefficient. Evaluation of GOCIAOT with AERONET measurements showed that the average error becomes 0.107 from the original 0.393, that means GOCI aerosol optical thickness can be more accurately with the advanced two-stream approximation. Taking the eastern China in 3 and 4 December 2013 for example, comparing the GOCIAOT at 555nm, MODISAOT retrievals at 550nm, NPPAOT at 550nm and AERONET data products indicated that: take the AERONET data as reference, the error of three kinds of satellite data can be ordered as following: MODISAOT< GOCIAOT< NPPAOT and the GOCI-MODIS shows a bias of 0.02917 with the GOCI-NPP. GOCIAOT is 0.05714 generally bigger than that of MODISAOT. NPP-GOCI deviation is 0.10253. The deficiency of MODIS is its low spatial resolution and the high concentration of AOT will be mistaken for a cloud area. However, GOCI can well reflect the concentration and distribution of aerosols. Therefore, GOGI can provide real-time dynamic monitoring on China Eastern atmospheric environment and the accurate time event information of haze for each process can be obtained. Finally, applied GOCI to the "8.12 Tianjin bombings" and to monitor the migration and dispersion of pollutant.

  13. Body fat measurement in elite sport climbers: comparison of skinfold thickness equations with dual energy X-ray absorptiometry.

    Science.gov (United States)

    Espana Romero, Vanesa; Ruiz, Jonatan R; Ortega, Francisco B; Artero, Enrique G; Vicente-Rodriguez, German; Moreno, Luis A; Castillo, Manuel J; Gutierrez, Angel

    2009-03-01

    The aim of this study was to compare equations for estimating percentage body fat from skinfold thickness in elite sport climbers by assessing their agreement with percentage body fat measured using dual-energy X-ray absorptiometry (DXA). Skinfold thickness was measured in a convenience sample of 19 elite sport climbers [9 women and 10 men; mean age 31.2 years (s = 5.0) and 28.6 years (s = 3.6), respectively]. Percentage body fat was estimated using 17 different equations, and it was also measured by DXA. A significant inter-methods difference was observed for all equations, except for Durnin's equation in men (inter-methods difference: -0.57% and -0.29%; 1.96 s: 5.56 and 5.23 for Siri's and Brozek's equation, respectively) and women (inter-methods difference: -0.67% and -1.29% for Siri's and Brozek's equation, respectively), and for Wilmore's equation using Siri's body fat equation in women (inter-methods difference: -1.86%). In women, the limits of agreement were lower when using Durnin's equation compared with Wilmore's equation (1.96 s: 3.86% and 5.13%, respectively). In conclusion, of the 17 studied equations, Durnin's equation was the most accurate in estimating percentage body fat in both male and female elite climbers. Therefore, Durnin's equation could be used to assess percentage body fat in elite sport climbers if more accurate methods are not available. The generalizability of the results is limited by the fact that the sample was not selected at random.

  14. Four-spacecraft determination of magnetopause orientation, motion and thickness: comparison with results from single-spacecraft methods

    Directory of Open Access Journals (Sweden)

    S. E. Haaland

    2004-04-01

    Full Text Available In this paper, we use Cluster data from one magnetopause event on 5 July 2001 to compare predictions from various methods for determination of the velocity, orientation, and thickness of the magnetopause current layer. We employ established as well as new multi-spacecraft techniques, in which time differences between the crossings by the four spacecraft, along with the duration of each crossing, are used to calculate magnetopause speed, normal vector, and width. The timing is based on data from either the Cluster Magnetic Field Experiment (FGM or the Electric Field Experiment (EFW instruments. The multi-spacecraft results are compared with those derived from various single-spacecraft techniques, including minimum-variance analysis of the magnetic field and deHoffmann-Teller, as well as Minimum-Faraday-Residue analysis of plasma velocities and magnetic fields measured during the crossings. In order to improve the overall consistency between multi- and single-spacecraft results, we have also explored the use of hybrid techniques, in which timing information from the four spacecraft is combined with certain limited results from single-spacecraft methods, the remaining results being left for consistency checks. The results show good agreement between magnetopause orientations derived from appropriately chosen single-spacecraft techniques and those obtained from multi-spacecraft timing. The agreement between magnetopause speeds derived from single- and multi-spacecraft methods is quantitatively somewhat less good but it is evident that the speed can change substantially from one crossing to the next within an event. The magnetopause thickness varied substantially from one crossing to the next, within an event. It ranged from 5 to 10 ion gyroradii. The density profile was sharper than the magnetic profile: most of the density change occured in the earthward half of the magnetopause.

    Key words. Magnetospheric physics (magnetopause, cusp and

  15. 超厚粘土层冻结壁与井壁温度场实测研究%Site Measurement Study on Temperature Filed of Freezing Wall and Mine Shaft Liner in Ultra Thick Clay Stratum

    Institute of Scientific and Technical Information of China (English)

    杨国强; 姜国静; 高伟; 马冠超

    2014-01-01

    张集煤矿副井井深280.52~449.69m段有一单层厚度达169m的超厚粘土层,以膨胀性厚粘土为主,为目前国内穿越单层粘土最厚的立井。根据该井筒内、外层井壁厚度及混凝土强度等级的不同,共布置6个监测水平,对粘土层冻结壁与井壁温度场进行了实测研究。结果表明,受混凝土初期水化放热与冻结管冷量供应的影响,外壁温度变化曲线明显呈现3个阶段,即线性快速增长阶段、非线性快速下降阶段和趋于稳定阶段。冻结壁内部温度变化趋势相对较平缓,始终处于负温状态。邻近井帮冻土在外壁混凝土浇筑后的2d内,达到最大融化距离,为200mm左右。邻近井帮融土在外壁混凝土浇筑后的12~14d内,首先进入负温状态,即产生回冻现象。在冻结壁与外壁间铺设泡沫塑料板,可在一定程度上减小混凝土水化放热与冻结管冷量供应间的相互影响。%An auxiliary shaft of Zhangji Mine was a deep mine shaft.There was an ultra thick clay stra-tum with a thickness of 169m located in the mine shaft at a depth section from 280.52~449.69m.The ultra thick clay stratum was swelling thick clay mainly and was a single highest thick clay stratum pas-sed by a mine shaft in China.According to the thickness of the mine internal and external shaft liners and the different grade of the concrete strength ,there were 6 monitoring and measuring levels set in the mine shaft and a site measurement study was conducted on the temperatures fields of the freezing wall and the mine shaft liner in the clay stratum.The results showed that due to influenced by the ini-tial hydration heat emission of the concrete and the refrigeration supply of the freezing pipe ,a tempera-ture variation curve of the external shaft liner would have three stages obviously and they were a linear rapid increasing stage ,nonlinear rapid decreasing stage and stable stage.An inner temperature varia

  16. Cigarette smoking in military pilots and intima-media thickness of the carotid arteries

    Directory of Open Access Journals (Sweden)

    Jovelić Stojan

    2005-01-01

    Full Text Available Background. It is well known that smoking is associated with an increase in arterial wall thickness. However, most studies of this problem have been undertaken in age and sex heterogeneous groups, as well as in patients with already present other conventional risk factors. The aim of this study was to assess the effect of cigarette smoking on arterial wall thickness of the common carotid artery in asymptomatic pilots. Methods. The imaging of intima−media thickness of the posterior wall of the distal 1 cm of both common carotid arteries was performed using a B mode ultrasound device, in 39 pilots (37.05 ± 6.66 years, for whom smoking was the single cardiovascular risk factor. Comparisons were made with 49 non-smokers (35.12 ± 7.39 years. Results. The posterior walls of both common carotid arteries were thicker in smokers (left, p < 0.05; right, p > 0,05. Intima-media thickness was significantly lower on the right side than on the left side in both smokers and nonsmokers (p < 0.01. Conclusion. Cigarette smoking as the single cardiovascular risk factor was associated with the wall thickness of the carotid arteries in our study. This finding indicated that early atherosclerosis was already present in pilots - smokers entering middle age.

  17. Bubble Impact with a Solid Wall

    Science.gov (United States)

    Garg, Vishrut; Thete, Sumeet; Basaran, Osman

    2016-11-01

    In diverse natural and industrial processes, and in particular in process equipment widely used in oil and gas production, bubbles and drops that are immersed in a continuous liquid phase frequently collide with solid walls. In this talk, the impact with a solid wall of a gas bubble that is surrounded by a liquid that is either a Newtonian or a non-Newtonian fluid is analyzed by numerical simulation. Special attention is paid to the thin film that forms between the approaching bubble and the solid wall. Flow regimes that arise as the film thickness decreases are scrutinized and rationalized by comparison of the computational predictions to well-known and new analytical results from lubrication theory based thin film literature. Finally, flow transitions that occur as the lubrication theory breaks down and inertia becomes significant are investigated.

  18. High-resolution intracranial vessel wall MRI in an elderly asymptomatic population: comparison of 3T and 7T

    Energy Technology Data Exchange (ETDEWEB)

    Harteveld, Anita A.; Kolk, Anja G. van der; Dieleman, Nikki; Siero, Jeroen C.W.; Luijten, Peter R.; Zwanenburg, Jaco J.M.; Hendrikse, Jeroen [University Medical Center Utrecht, Department of Radiology, Postbox 85500, Utrecht (Netherlands); Worp, H.B. van der; Frijns, Catharina J.M. [University Medical Center Utrecht, Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, Utrecht (Netherlands); Kuijf, Hugo J. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands)

    2017-04-15

    Several intracranial vessel wall sequences have been described in recent literature, with either 3-T or 7-T magnetic resonance imaging (MRI). In the current study, we compared 3-T and 7-T MRI in visualising both the intracranial arterial vessel wall and vessel wall lesions. Twenty-one elderly asymptomatic volunteers were scanned by 3-T and 7-T MRI with an intracranial vessel wall sequence, both before and after contrast administration. Two raters scored image quality, and presence and characteristics of vessel wall lesions. Vessel wall visibility was equal or significantly better at 7 T for the studied arterial segments, even though there were more artefacts hampering assessment. The better visualisation of the vessel wall at 7 T was most prominent in the proximal anterior cerebral circulation and the posterior cerebral artery. In the studied elderly asymptomatic population, 48 vessel-wall lesions were identified at 3 T, of which 7 showed enhancement. At 7 T, 79 lesions were identified, of which 29 showed enhancement. Seventy-one percent of all 3-T lesions and 59 % of all 7-T lesions were also seen at the other field strength. Despite the large variability in detected lesions at both field strengths, we believe 7-T MRI has the highest potential to identify the total burden of intracranial vessel wall lesions. (orig.)

  19. 超声TOFD技术在小径厚壁管检测中的应用%Application of Ultrasonic TOFD Technique on Small Diameter Thick-Wall Pipe

    Institute of Scientific and Technical Information of China (English)

    齐向前

    2011-01-01

    Abstract: Ultrasonic TOFD technique was used to detect the pipe for specification of Ф 80 mm×19 mm. Regulation means of instrument parameters were explained for the wedge block after grinding and sensitivity comparison test was operated on the same thickness steel plate. The experimental result showed that the defect could be detected effectively after the wedge block being worn to the curvature as the pipe to be tested. Compared to the same thickness steel plate, no obvious change was observed for the test sensitivity.%应用超声TOFD技术对规格为Ф80mm×19mm的小径厚壁管进行了检测。阐述了TOFD探头楔块修磨后仪器相关参数的调整方法,并与相同厚度钢板进行了检测灵敏度对比。试验结果表明,TOFD探头楔块修磨至与被检管材相同曲率后,能够对焊缝内缺陷有效检出,且楔块修磨后检测灵敏度与相同厚度板材检测灵敏度相比,没有明显变化。

  20. Comparison of papilla healing following sulcular full-thickness flap and papilla base flap in endodontic surgery.

    Science.gov (United States)

    Velvart, P; Ebner-Zimmermann, U; Ebner, J P

    2003-10-01

    To compare the loss of papilla height when using the papilla base incision (PBI) or the standard papilla mobilization incision in marginal full-thickness flap in cases with no evidence of marginal periodontitis. Twelve healthy patients referred for surgical treatment of persisting apical periodontitis, who were free from periodontal disease and had intact interdental papillae, were included in the study. The preoperative papilla height was recorded by measuring the distance between a reproducible coronal point on the tooth and the most coronal point of the papilla. The flap design consisted of two releasing incisions connected by a horizontal incision. The marginal incision involved the complete mobilization of the entire papilla in one interproximal space, and the PBI in the other interproximal space. The PBI consisted of a shallow first incision at the base of the papilla and a second incision directed to the crestal bone creating a split thickness flap in the area of the papilla base. Further, apically, a full-thickness flap was raised. In the other interproximal space, the buccal papilla was carefully incised and elevated completely. Following flap retraction, standard root-end resection and root-end filling were performed. Flap closure was achieved with microsurgical sutures. The PBI was sutured with two to three interrupted sutures (size 7/0) and the elevated papilla was reapproximated with vertical mattress sutures, which were removed 3-5 days after the surgery. The height of the interdental papilla was evaluated preoperatively and postoperatively after 1 month and at the 3-month recall, using plaster replicas. The loss of papilla height was measured using a laser scanner. Twelve papilla-paired sites were evaluated. The results were statistically analysed using the t-test. Complete closure of the wound was achieved in all treated sites followed by uneventful healing in all patients. The total mobilization of the papilla resulted in loss of papilla height of

  1. Comparison of carotid artery intima - media thickness and risk factors of atherosclerosis in lacunar versus non-lacunar cerebral infarcts

    Directory of Open Access Journals (Sweden)

    Seyed Ali Mousavi

    2007-07-01

    Full Text Available

    BACKGROUND: Increases in the thickness of the intima-media of the carotid artery have been associated with an increased risk of myocardial infarction and stroke in subjects without a history of cardiovascular disease. Lacunar infarcts, one of the most common subtypes of ischemic stroke, show unique pathological and clinicoradiological characteristics. The present study examined the relationship between the vascular risk factors, including carotid artery intimamedia thickness (IMT, and lacunar versus non-lacunar infarcts.
    METHODS: We collected data from patients admitted to hospital with acute ischemic stroke. 195 Patients and 96 control subjects underwent B-mode ultrasonographic measurements of IMT of the common carotid artery. We examined the association of lacunar and non-lacunar infarcts with age, sex, and potential vascular risk factors.
    RESULTS: Of 195 adult patients with acute ischemic stroke, 87 were considered lacunar and 108 were considered nonlacunar strokes. Between these two groups of patients, we did not find a significantly different percentage of diabetes,
    smoking, hypertension, dyslipidemia, myocardial infarction, or previous history of ischemic stroke, alcohol, obesity,
    atherogen diet, exercise, and IMT. However, patients with lacunar infarct, diabetes mellitus (P = 0.02, and hypertension
    (P = 0.02 had a significantly higher percentage of history of prior CVA (P = 0.03 and a significantly higher percentage
    of non-lacunar infarct.
    CONCLUSIONS: The present results indicated that diabetes mellitus and hypertension are more common in patients with lacunar infarcts, and history of CVA is more common in patients with non–lacunar infarcts. We further concluded that IMT cannot differentiate subtypes of ischemic stroke. Because risk factors and clinical presentation of ischemic stroke differ among races, more national studies

  2. Comparison of long-term papilla healing following sulcular full thickness flap and papilla base flap in endodontic surgery.

    Science.gov (United States)

    Velvart, P; Ebner-Zimmermann, U; Ebner, J P

    2004-10-01

    To compare long-term loss of papilla height when using either the papilla base incision (PBI) or the standard papilla mobilization incision in marginal full thickness flap procedures in cases with no evidence of marginal periodontitis. Twelve healthy patients, free of periodontal disease, who had intact interdental papillae were referred for surgical treatment of persisting apical periodontitis and included in the study. The flap design consisted of two releasing incisions connected by a horizontal incision. The marginal incision involved the complete mobilization of the entire papilla in one interproximal space but in the other interproximal space the PBI was performed. Further apically a full thickness flap was raised. Following flap retraction, standard apical root-end resection and root-end filling was performed. Flap closure was achieved with microsurgical sutures. The PBI was sutured with two to three interrupted sutures (size 7/0), the elevated papilla was reapproximated with vertical mattress sutures (size 7/0), which were removed 3-5 days after the surgery. The height of the interdental papilla was evaluated preoperatively and postoperatively after 1-, 3- and 12-month recall using plaster replicas. The loss of papilla height was measured using a laser scanner. Papilla paired sites were evaluated and statistically analysed. Most papilla recession took place within the first month after the surgery in the complete elevation of the papilla. Further small increase in loss of papilla height resulted at 3 months. After 1 year the loss of height diminished to 0.98 +/- 0.75 mm, but there was no statistical difference between the various recall intervals. In contrast, after PBI only minor changes could be detected at all times. There was a highly significant difference between the two incision techniques for all recall appointments (P < 0.001). In the short as well as long-term the PBI allows predictable recession-free healing of the interdental papilla. In

  3. Kinetic and analytical comparison of horseradish peroxidase on bare- and redox-modified single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Palangsuntikul, Rungtiva [Biological Engineering Program, King Mongkut' s University of Technology Thonburi, Bangmod Campus, Pracha-utit Rd., Bangkok 10140 (Thailand); Somasundrum, Mithran, E-mail: mithran.somasundrum@gmail.co [Biochemical Engineering and Pilot Plant Research and Development Unit, National Center for Genetic Engineering and Biotechnology, Phahonyothin Rd., Prathumthani 12120 (Thailand); Surareungchai, Werasak, E-mail: werasak.sur@kmutt.ac.t [Biological Engineering Program, King Mongkut' s University of Technology Thonburi, Bangmod Campus, Pracha-utit Rd., Bangkok 10140 (Thailand); School of Bioresources and Technology, King Mongkut' s University of Technology Thonburi, Bangkhuntien Campus, Bangkhuntien-Chaitalay Rd., Bangkok 10150 (Thailand)

    2010-12-15

    Single-walled carbon nanotubes (SWNTs) were coated first with methylene blue (MB) by noncovalent adsorption and then by horseradish peroxidase (HRP) by cross-linking with glutaraldehyde. The MB-SWNT/HRP composites formed stable films on glassy carbon electrodes. MB was probably present with a coverage of a monolayer or less. The MB voltammetry was consistent with fast electron transfer to a surface-confined species. The presence of HRP did not significantly affect the MB electrochemistry. MB could mediate electron transfer from HRP in the presence of H{sub 2}O{sub 2}. Cyclic voltammograms of this process were used to determine the rate constants for the reactions of the native ferriperoxidase with H{sub 2}O{sub 2} and of the oxyferryl Compound II with the reduced form of MB. For comparison purposes, the rate constant for the direct electrode reduction of the HRP oxyferryl {pi}-cation radical Compound I was determined in MB-free SWNTs. The results indicate a considerably faster regeneration rate for native ferriperoxidase by the mediated reaction than by direct electrochemistry. Using the MB-SWNT/HRP composites, H{sub 2}O{sub 2} could be calibrated by amperometry at -0.3 V vs. SCE. The optimized response (at pH 7.0) had a sensitivity of 661.0 {mu}A mM{sup -1} cm{sup -2} and a limit of detection (3 x S/N) of 0.1 {mu}M.

  4. Progress in steel used for large-calibre thick-wall gun barrel%大口径厚壁火炮身管用钢的性能与发展

    Institute of Scientific and Technical Information of China (English)

    吕彦; 胡俊; 任泽宁; 黄建文; 李绵

    2013-01-01

    以炮钢标准为依据,综述了厚壁炮钢材料的现状及炮钢性能的发展,论述了炮钢材料的特殊要求和炮钢的发展方向以及炮钢发展的技术途径.新型高强韧炮钢的研发要结合新工艺新技术的应用,开展精细组织的控制、晶粒细化等技术的研究,提高钢的综合性能.%Current status and progress of the mechanical properties of thick-wall gun steel are reviewed on the basis of gun steel standards.Special requirements and development direction as well as technical approaches of gun steel material are discussed. The development of new high strength and high toughness gun steel should be focused on improving the comprehensive properties by application of advanced techniques and processes, such as microstructure controlling, grain refinement and so on.

  5. Comparison of central corneal thickness measurements using optical low-coherence reflectometry, Fourier domain optical coherence tomography, and Scheimpflug camera

    Directory of Open Access Journals (Sweden)

    Saban Gonul

    2014-12-01

    Full Text Available Purpose: To compare the results of central corneal thickness (CCT measurements obtained using optical low-coherence reflectometry (OLCR, Fourier domain optical coherence tomography (FD-OCT, and a Scheimpflug camera (SC, combined with Placido corneal topography. Methods: A total of 25 healthy subjects were enrolled in the present study, and one eye of each subject was included. A detailed ophthalmic examination was performed in all cases following CCT measurements with OLCR, FD-OCT, and SC. The results were compared using an ANOVA test. Bland-Altman analysis was used to demonstrate agreement between methods. Intra-examiner repeatability was assessed by using intraclass correlation coefficients (ICCs. Results: Statistically significant differences were observed between the results of the CCT measurements obtained using the three different devices (p=0.009. Significant correlations were found between OLCR and FD-OCT (r=0.97; p0.98. Conclusion: Although the results of CCT measurements obtained from these three devices were highly correlated with one another and the mean differences between instruments were comparable with the reported diurnal CCT fluctuation, the measurements are not directly interchangeable in clinical practice because of the wide LOA values.

  6. A Comparison of Healing Effects of Propolis and Silver Sulfadiazine on Full Thickness Skin Wounds in Rats

    Directory of Open Access Journals (Sweden)

    E. Moghtaday Khorasgani*, A. H. Karimi and M. R. Nazem

    2010-04-01

    Full Text Available Healing effects of propolis and silver sulfadiazine (SS on skin wounds in rats were compared using qualitative and quantitative parameters and histopathological findings. A total of 30 full thickness skin wounds were created on dorsal aspects of 10 rats; i.e., three wounds on each rat. Of these wounds, 10 each were allocated to group A (propolis, group B (SS and group C (control. The skin wounds in the rats of groups A, B and C were covered daily for 14 days with 50% propolis cream, SS skin cream and bepanthane cream (control, respectively. Postoperatively, the wound surfaces were examined macroscopically and the healing process and the rates of wound expansion, contraction and epithelialization processes were quantitatively analyzed. As a result, propolis was found in general to have a better wound healing effect than others. At the 10th day of experiment histopathologically, there was inflammatory reaction with infiltration of lymphocytes, macrophages and neutrophils and proliferation of fibroblastic loose connective tissue in dermis of rats of all groups. The severity of these changes was lower in propolis treated group compared to other two groups.

  7. Thick-walled carbon composite multifunctional structures

    Science.gov (United States)

    Haake, John M.; Jacobs, Jack H.; McIlroy, Bruce E.

    1997-06-01

    Satellite programs are moving in the direction of smaller and lighter structures. Technological advances have permitted more sophisticated equipment to be consolidated into compact spaces. Micro-satellites, between 10 and 100 kg, will incorporate micro-electric devices into the lay-up of the satellite structure. These structures will be designed to carry load, provide thermal control, enhance damping, and include integrated passive electronics. These multifunctional structures offer lighter weight, reduced volume, and a 'smarter' overall package for incorporation of sensors, electronics, fiber optics, powered appendages or active components. McDonnell Douglas Corporation (MDC) has applied technology from the synthesis and processing of intelligent cost effective structures (SPICES) and independent research and development (IRAD) programs to the modular instrument support system (MISS) for multifunctional space structures and micro-satellites. The SPICES program was funded by the Defense Advanced Research Projects Agency (DARPA) to develop affordable manufacturing processes for smart materials to be used in vibration control, and the MISS program was funded by NASA-Langley. The MISS program was conceived to develop concepts and techniques to make connections between different multifunctional structures. MDA fabricated a trapezoidal carbon composite structure out of IM7/977-3 tape prepreg. Flex circuits, thermal and optical conduits were embedded to realize a utility modular connector. These provide electrical, thermal, optical and mechanical connections between micro- satellite components. A quick disconnect mount was also developed to accommodate a variety of devices such as solar arrays, power sources, thermal transfer and vibration control modules.

  8. Comparison of choroidal thickness measurements between spectral-domain OCT and swept-source OCT in normal and diseased eyes

    Directory of Open Access Journals (Sweden)

    Zafar S

    2016-11-01

    Full Text Available Sidra Zafar,1 MA Rehman Siddiqui,2,3 Rida Shahzad1 1Medical College, Aga Khan University Hospital, 2Department of Ophthalmology, Shahzad Eye Hospital, 3South City Hospital, Karachi, Pakistan Purpose: Sub-foveal choroidal thickness (SFCT is affected in many ocular diseases. The aim of this study was to compare SFCT measurements between Topcon 3D 2000 spectral-domain optical coherence tomography (SD-OCT and Topcon swept-source OCT (SS-OCT, with different laser wavelengths, in normal and diseased populations. Materials and methods: This was a prospective, cross-sectional, noninterventional study including 27 normal volunteers and 27 participants with retinal disease. OCT scans were performed sequentially and under standardized conditions using both SD-OCT and SS-OCT. The OCT scans were evaluated by two independent graders. Paired t-tests and intraclass correlation coefficients (ICCs were used to assess the statistically significant difference between SFCT measurements as measured by the two devices. Results: Mean SFCT measurements for all 54 participants were 264.9±103.1 µm using SD-OCT (range: 47–470 µm and 278.5±110.5 µm using SS-OCT (range: 56–502 µm, with an inter-device ICC of 0.850. Greater variability was noted in the diseased eyes. Inter-device ICCs were 0.870 (95% CI; 0.760–0.924 and 0.840 (95% CI; 0.654–0.930 for normal and diseased eyes, respectively. However, the difference was not statistically significant (P=0.132. Conclusion: Both machines reliably measure SFCT. Larger studies are needed to confirm these findings. Keywords: choroidal imaging, diseased, normal, SD-OCT, SS-OCT

  9. Comparison of intima-media thickness of common and internal carotid arteries of patients with ischemic stroke and intracerebral hemorrhage.

    Directory of Open Access Journals (Sweden)

    Ali Moghtaderi

    2014-12-01

    Full Text Available Role of atherosclerosis in the pathogenesis of ischemic and hemorrhagic infarctions is still matter of debate. Intima-media thickness (IMT of the common carotid artery (CCA and internal carotid artery (ICA are markers of atherosclerosis. The aim of this study was to compare CCA IMT and ICA IMT of patients with ischemic and hemorrhagic infarction.Two equal groups of 80 patients with small and large vessel ischemic stroke and 80 patients with non-traumatic intracerebral hemorrhage (ICH who referred to our central teaching hospital of Zahedan were assessed in this descriptive study. IMT of four arteries (right and left CCA and ICA were measured, and collected data were analysis using Student's t-test.There were 137 males (57.1% and 103 (42.9% female with mean age of 62.7 ± 11.7. Mean right CCA IMT of patients with small vessel diseases (SVD, large vessel diseases (LVD, and ICH were 0.564 ± 0.130, 0.623 ± 0.150, and 0.580 ± 0.140 mm, respectively (P = 0.032. Mean left CCA IMT of patients with SVD, LVD, and ICH were 0.569 ± 0.120, 0.618 ± 0.120, and 0.573 ± 0.130 mm, respectively (P = 0.039. The above findings for right ICA were 0.572 ± 0.120, 0.569 ± 0.140, and 0.522 ± 0.130 mm, respectively (P = 0.145. Those findings for left ICA IMT were 0.525 ± 0.110, 0.554 ± 0.120, and 0.527 ± 0.120 mm, respectively (P = 0.257.Our findings showed that by using CCA IMT, differentiation between small and large vessel infarctions and hemorrhagic infarctions can be made.

  10. Comparison of the effects of surgical and natural menopause on carotid intima media thickness, osteoporosis, and homocysteine levels.

    Science.gov (United States)

    Özkaya, Enis; Cakir, Evrim; Okuyan, Erhan; Cakir, Caner; Ustün, Gülnihal; Küçüközkan, Tuncay

    2011-01-01

    Menopause is associated with increased cardiovascular risk factors. We designed this study to compare common carotid artery intima media thickness (IMT) and homocysteine level between women who had natural menopause and those who had surgical menopause and to correlate IMT, bone mineral density (BMD), and homocysteine level with time since menopause. Ninety healthy postmenopausal women aged 50 to 78 years who were not on hormone therapy (45 women who did not have a prior hysterectomy or oophorectomy and 45 women who had undergone hysterectomy with bilateral oophorectomy) were included in the study. B-mode ultrasonography of the carotid artery, BMD, and serum homocysteine level analysis were completed to evaluate the relationship between type of menopause, time since menopause, and subclinical atherosclerosis. Mean ± SD carotid artery IMT measurements were 0.72 ± 0.002 mm among women experiencing natural menopause and 0.88 ± 0.003 mm among women having bilateral oophorectomy (P = 0.002). After adjusting for time since menopause and age, the mean IMT also differed between the two groups: 0.76 ± 0.003 mm in the natural menopause group and 0.84 ± 0.003 mm in the bilateral oophorectomy group (P = 0.038). The age-adjusted carotid IMT was significantly positively associated with years since menopause (P = 0.001). Mean homocysteine measurements were 10.3 ± 5 μmol/L among women experiencing natural menopause and 9.1 ± 4 μmol/L among women who had bilateral oophorectomy (P = 0.216). Age-adjusted femur total, trochanter, and shaft BMDs were significantly lower in the surgical menopause group (P = 0.041, P = 0.034, and P = 0.046, respectively). Oophorectomy before natural menopause increases IMT but not homocysteine levels independent of age and time since menopause and is associated with lower BMD values after adjustment for age.

  11. Comparison of Carotid Intima-Media Thickness in Pediatric Patients with Metabolic Syndrome, Heterozygous Familial Hyperlipidemia and Normals

    Directory of Open Access Journals (Sweden)

    Arvind Vijayasarathi

    2014-01-01

    Full Text Available Background. Our goal was to compare the carotid intimal-medial thickness (CIMT of untreated pediatric patients with metabolic syndrome (MS, heterozygous familial hyperlipidemia (heFH, and MS+heFH against one another and against a control group consisting of healthy, normal body habitus children. Methods. Our population consisted of untreated pediatric patients (ages 5–20 yrs who had CIMT measured in a standardized manner. Results. Our population included 57 with MS, 23 with heFH, and 10 with MS+heFH. The control group consisted of 84 children of the same age range. Mean CIMT for the MS group was 469.8 μm (SD = 67, 443.8 μm (SD = 61 for the heFH group, 478.3 μm (SD = 70 for the MS+heFH group, and 423.2 μm (SD = 45 for the normal control group. Significance differences between groups occurred for heFH versus MS (P=0.022, heFH versus control (P=0.038, MS versus control (P=9.0E-10, and MS+heFH versus control (P=0.003. Analysis showed significant negative correlation between HDL and CIMT (r=-0.32,  P=0.03 but not for LDL, triglycerides, BP, waist circumference, or BMI. Conclusion. For pediatric patients, the thickest CIMT occurred for patients with MS alone or for those with MS+heFH. This indicates that MS, rather than just elevated LDL, accounts for more rapid thickening of CIMT in this population.

  12. Comparison of survival time and comfort between 2 clear overlay retainers with different thicknesses: A pilot randomized controlled trial.

    Science.gov (United States)

    Zhu, Yafen; Lin, Jianchang; Long, Hu; Ye, Niansong; Huang, Renhuan; Yang, Xin; Jian, Fan; Lai, Wenli

    2017-03-01

    The objective of this 2-arm parallel trial was to compare the survival times, failure rates, and comfort of 2 clear overlay retainers with different thicknesses (0.75 and 1.00 mm). Eighty eligible participants who had undergone orthodontic treatment at West China Stomatology Hospital of Sichuan University were recruited and randomly assigned to either the 0.75-mm group or the 1.00-mm group. Eligibility criteria included patients with central incisors, canines, and first molars and no systemic or oral disease. The main outcomes were survival time and total failure rate; the secondary outcomes were rates of different types of failure (fracture, loss, nonfitting, and abrasion); tertiary outcomes included patients' comfort levels assessed with a visual analog scale and a health survey. Randomization was accomplished by tossing a coin, with the allocations concealed in sequentially numbered, opaque, sealed envelopes, and blinding implemented among practitioners, patients, and analysts. Patients were evaluated at 1, 3, 6, and 12 months of follow-up. A total of 80 patients were initially recruited and randomized (42 in the 0.75-mm group, 38 in the 1.00-mm group); 72 patients completed the study and were analyzed (37 in the 0.75-mm group, 35 in the 1.00-mm group); there were 8 dropouts. Baseline characteristics were similar between the groups. At the end of the 1-year follow-up, survival time did not differ significantly between the groups (46.5 days; 95% confidence interval [CI], -10.3 -103.2; P = 0.111). The hazard ratio was 0.77 (95% CI, 0.48-1.24; P = 0.281). With regard to total failure rate, no statistical difference (P = 0.118) existed between the 0.75-mm group (43.2%) and the 1.00-mm group (25.7%) (risk difference, 17.5%; 95% CI, -4.0%-39.1%). Among the different failure types, we found that fracture rates were significantly higher in the 0.75-mm group than in the 1.00-mm group (P = 0.028), whereas other failure types were similar between the groups

  13. LSER model for organic compounds adsorption by single-walled carbon nanotubes: Comparison with multi-walled carbon nanotubes and activated carbon.

    Science.gov (United States)

    Yu, Xiangquan; Sun, Weiling; Ni, Jinren

    2015-11-01

    LSER models for organic compounds adsorption by single and multi-walled carbon nanotubes and activated carbon were successfully developed. The cavity formation and dispersion interactions (vV), hydrogen bond acidity interactions (bB) and π-/n-electron interactions (eE) are the most influential adsorption mechanisms. SWCNTs is more polarizable, less polar, more hydrophobic, and has weaker hydrogen bond accepting and donating abilities than MWCNTs and AC. Compared with SWCNTs and MWCNTs, AC has much less hydrophobic and less hydrophilic adsorption sites. The regression coefficients (e, s, a, b, v) vary in different ways with increasing chemical saturation. Nonspecific interactions (represented by eE and vV) have great positive contribution to organic compounds adsorption, and follow the order of SWCNTs > MWCNTs > AC, while hydrogen bond interactions (represented by aA and bB) demonstrate negative contribution. These models will be valuable for understanding adsorption mechanisms, comparing adsorbent characteristics, and selecting the proper adsorbents for certain organic compounds.

  14. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Lois [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Mantha, Pallavi [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2013-05-01

    In this project, the Consortium for Advanced Residential Buildings (CARB) team evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls. Wall assemblies evaluated included code minimum walls using spray foam insulation and fiberglass batts, high R-value walls at least 12 in. thick (R-40 and R-60 assemblies), and brick walls with interior insulation.

  15. 超声波穿金属厚壁通信电路系统设计与实现%Design and Implementation of Ultrasonic Through-metal-thick-wall Communication Circuit System

    Institute of Scientific and Technical Information of China (English)

    李海廷; 杨涛

    2013-01-01

    A novel ultrasonic high voltage pulse transmitting circuit based on a energy storage inductance was presented after analyzing ultrasonic through-metal-thick-wall communication system that needs high frequency and high voltage. The control signal based on FPGA drived IGBT switch component with high precision and frequency. The receiving signal amplifier and bandpass filtering circuit were designed to achieve the stability of the ultrasonic receiving signal after analyzing the ultrasonic transmission condition in the medium interface. Data flows were restored based on FPGA after ultrasonic signal envelope detection and A/D sampling. The design scheme has important potential applications which realizes the information collection and transmission with high speed in sealed containers.%在分析超声波穿金属厚壁通信系统需要高频高压的基础上,设计了一种利用电感储能产生高压脉冲的发射电路.采用FPGA产生高精度高频控制信号,驱动IGBT开关元件.同时在对介质表面声波透射状况分析后,设计了接收信号放大和带通滤波电路,实现了超声信号的稳定接收.在接收信号包络检波和A/D采样转换后,通过FPGA处理实现了数据流的还原.该设计方案可实现密闭容器内信息的采集与高速传输,具有重要的应用前景.

  16. 厚壁T92钢焊接接头射线探伤工艺%X-ray Inspection Techniques of Thick Walled T92 Steel Welding Joint

    Institute of Scientific and Technical Information of China (English)

    张斌

    2013-01-01

    在1 000 MW超超临界机组锅炉受热面中引进了新型马氏体耐热钢T92,这种钢的合金元素含量较以前的锅炉用钢更高,但具有焊接冷裂纹倾向,裂纹缺陷对机组运行的危害性严重,因此对射线探伤裂纹的检出率要求更高.针对裂纹检出率问题对射线探伤工艺进行了试验,制定出了厚壁T92钢焊接接头射线探伤工艺,并在现场射线检验过程中证实了探伤工艺符合要求.%A new type of martensite heat-resisting steel T92 was introduced in 1 000 MW ultra-supercritical units, whose alloy element content was higher than former boiler steel.T92 steel is susceptible to welding cold cracks, imposing serious harmfulness on the unit operation.Therefore, the higher detection rate of crack is requested for X-ray testing technology.This paper showed some test results for satisfying a higher demand for radiation detection of cracks, put forward X-ray inspection technology for thick walled T92 steel welding joint.Field inspection confirmed that the technology met the requirement.

  17. Anti-TNF-Alpha-Adalimumab Therapy Is Associated with Persistent Improvement of Endothelial Function without Progression of Carotid Intima-Media Wall Thickness in Patients with Rheumatoid Arthritis Refractory to Conventional Therapy

    Directory of Open Access Journals (Sweden)

    Carlos Gonzalez-Juanatey

    2012-01-01

    Full Text Available To determine whether treatment with the anti-TNF-alpha blocker adalimumab yields persistent improvement of endothelial function and prevents from morphological progression of subclinical atherosclerosis in patients with rheumatoid arthritis (RA refractory to conventional therapy, a series of 34 consecutive RA patients, attending hospital outpatient clinics and who were switched from disease modifying antirheumatic drug therapy to anti-TNF-alpha-adalimumab treatment because of severe disease, were assessed by ultrasonography techniques before the onset of adalimumab therapy (at day 0 and then at day 14 and at month 12. Values of flow-mediated endothelium-dependent vasodilatation at day 14 and at month 12 were significantly higher (mean ± standard deviation (SD: 6.1±3.9%; median: 5.7% at day 14, and mean ± SD: 7.4±2.8%; median: 6.9% at month 12 than those obtained at day 0 (mean: 4.5±4.0%; median: 3.6%; P=0.03 and P<0.001, resp.. Endothelium-independent vasodilatation results did not significantly change compared with those obtained at day 0. No significant differences were observed when carotid artery intima-media wall thickness values obtained at month 12 (mean ± SD: 0.69±0.21 mm were compared with those found at day 0 (0.65±0.16 mm (P=0.3. In conclusion, anti-TNF-alpha-adalimumab therapy has beneficial effects on the development of the subclinical atherosclerosis disease in RA.

  18. 超声测量膀胱壁厚度预测脊柱裂患儿上尿路损害%Ultrasound-estimation of the bladder wall thickness in children with spina bifida occulta

    Institute of Scientific and Technical Information of China (English)

    邢璐; 胡金华; 王亚仑; 文建国; 夏慧敏; 温英泉; 李忠民

    2010-01-01

    Objective The objective of the study was to correlate ultrasonographic bladder wall thickness measurement(BWT) with urodynamic studies in children with spina bifida occulta. Methods The study included 22 spina bifida occulta (SBO) patients (aged 8. 8 ± 4. 9 years)with upper urinary tract dilation (UUTD) and 29 SBO patients (aged 9. 3 ± 5.3 years) without UUTD. Urodynamic studies were performed. Maximal detrusor pressure during filling or at leak, maximal amplitude detrusor overactivity and detrusor leak point pressure were recorded. After filling of 60% of expected bladder capacity(EBC), the BWT was measured via suprapubic ultrasound. UUTD was diagnosed with ultrasound. The differences in BWT between the 2 groups were analyzed. The correlation between BWT and urodynamic parameters was studied. The receiver operator characteristic (ROC) curve was used to find the association between the urodynamic parameters and BWT. Results There was a significant difference between bladder wall thickness in children with and without UUTD (3. 4 ± 0. 25 mm vs. 2. 5± 0. 45) mm, P<0. 05). The bladder wall thickness significantly correlated with the maximal amplitude detrusor overactivity, the detrusor leak point pressure and the maximal detrusor pressure during filling(r = 0. 85、0. 87 and 0. 91 ). As a prediction of UUTD, BWT greater than 3. 0 mm had specificity of 79. 4% and sensitivity of 90. 9%, a positive predictive value of 76. 9%, a negative predictive value of 92.0%. ROC analysis revealed that BWT had a high predictive value for unfavorable urodynamic patterns, with an area under the curve of 0. 929. Conclusions BWT can be used to predict UUTD. BWT >3. 0 mm appears to be a useful predictor of UUTD in children with spina bifida occulta.%目的 通过超声测定膀胱壁厚度和尿动力学检查测定膀胱功能,评价隐形脊柱裂患儿膀胱厚度和功能及上尿路损害的相关性,探讨用膀胱壁厚度评估隐性脊柱裂患儿上

  19. Reconstrucción de defectos torácicos de espesor total: Presentación de 8 casos de especial complejidad Reconstruction of full thickness defects on the chest wall: Presentation of 8 complex cases

    Directory of Open Access Journals (Sweden)

    J.M. Lasso

    2009-12-01

    Full Text Available Las lesiones de gran tamaño en el tórax, requieren casi siempre para su reparación plastias complejas, que en algunos casos han de combinar el uso de tejidos autólogos y/o materiales sintéticos. Por tanto, la reconstrucción de la pared torácica supone un desafío desde el punto de vista reconstructivo en el que es fundamental el papel de los cirujanos plásticos. Los grandes defectos torácicos suelen ser secundarios a exéresis tumoral (tumores parietales de origen primario o secundario, infecciones, radionecrosis, traumatismos y malformaciones congénitas. Si bien los principios de la reconstrucción del tórax exigen una escisión amplia de la lesión, desbridamiento de los tejidos desvitalizados o irradiados y control de la infección local, dichas actuaciones no podrían abordarse con seguridad si no dispusiéramos de un amplio arsenal de técnicas reconstructivas, capaces de aportar tejidos sanos y bien vascularizados o voluminosos y amplios en superficie, junto con soportes rígidos mediante materiales aloplásticos. Gracias a estos avances, en la mayoría de los casos conseguimos el objetivo con sólo una intervención, cuando hace unos años necesitábamos varios procedimientos quirúrgicos. Presentamos una muestra variada de la experiencia de nuestro Servicio en el tratamiento de grandes defectos del tórax, en el que resumimos las distintas posibilidades que podemos encontrar en la práctica clínica diaria, y las soluciones que mejor se adaptan a las mismas.Reconstruction of full thickness defects on the chest wall is controversial and require the use of complex techniques that combine autologous tissue and/or alloplastic materials. Thus it is a challenge for plastic surgeons since it needs a suitable and functional reconstruction. The aethiology for these defects include tumoral surgery (primary wall tumors, or recurrences or metastasis, infections, radiation injury, trauma and congenital defects. Otherwise, first surgical

  20. Nano-metrology of porous structures — I Comparison of measured neutron scattering with calculated scattering to access pore lattice, diameter, and wall parameters, using models of extended arrays of regular or randomised pores

    Energy Technology Data Exchange (ETDEWEB)

    Webber, J. Beau W., E-mail: J.B.W.Webber@kent.ac.uk

    2013-05-15

    Neutron scattering offers a length-scale-independent method of probing structured matter on an atomic scale through nano-scale to meso-scale. A protocol is presented that provides a versatile method of determining structure, by comparison of measured and calculated neutron scattering, for any structural distribution that can be described algebraically or numerically, requiring no particular model other than the model of the structure, and needing no adjustable parameters other than the scale and other parameters describing the physical model. The method enables the direct comparison of measured and calculated scattering from structured matter: from simple finite and infinite bodies, from extended regular array of pores, or from extended arrays of pores with a partially randomised character. Examples are given for the radial distributions of a range of regular bodies, of large arrays of highly ordered porous materials such as templated SBA-15 and MCM-41 silicas, as well as for more disordered materials such as sol–gel silicas. Monte Carlo integration of the calculated scattering for ensembles of up to about 100,000 pores has been studied using these techniques. The method enables the calculation of the solid–solid density correlation function G(r) for model systems, and hence, by Fourier transformation, the expected scattering. Example measured scattering is compared with the calculated scattering, with further data presented in a related paper. The technique allows the direct calculation and comparison with measurement of all three of the main pore structural parameters: lattice spacing, pore diameter, and pore-wall thickness. Example SBA-15 wide and small angle neutron scattering (SANS) data, measured on NIMROD (the Near and InterMediate Range Order Diffractometer at ISIS), is used as an initial evaluation of the applicability of the techniques. The method is also applicable to determining structure by comparing calculating with measured diffraction broadening

  1. Comparison of the effect of grounding the column wall in gas-solid fluidized beds on electrostatic charge generation

    Energy Technology Data Exchange (ETDEWEB)

    Sowinski, Andrew; Mayne, Antonio; Javed, Bassam; Mehrani, Poupak, E-mail: poupak.mehrani@uottawa.ca [University of Ottawa, Chemical and Biological Engineering Department, 161 Louis Pasteur St., Ottawa, Ontario, K1N 6N5 (Canada)

    2011-06-23

    In gas-solid fluidized beds as particles are fluidized, they continuously come into contact with other particles, as well as the fluidization column wall. This generates electrostatic charges by means of triboelectrification and frictional charging, leading to particle agglomeration, reactor wall fouling, and eventually process downtime and large financial losses. Grounding the fluidization column has been considered as a means of helping electrostatic charge dissipation within fluidized beds; however, in industrial applications despite the process vessels being grounded, the electrostatic problem still persists. This work focused on the effect of fluidization column grounding on particle wall fouling. Experiments were conducted in an atmospheric system consist of a 0.1 m in diameter carbon steel fluidization column. The mass and charge-to-mass ratio (q/m) of the particles that remained adhered to the column wall upon the completion of one hour fluidization period were measured in an electrically isolated and grounded columns to quantitatively determine the amount of reactor wall fouling. Polyethylene particles with different particle size ranges (300- 1000 {mu}m) were fluidized with extra dry air at 1.5 times their respective minimum fluidization velocity (u{sub mf}). Results obtained in the grounded fluidization column were not significantly different from those in the isolated column for all particle size ranges tested where the particles mass collected and q/m and were found to be generally similar.

  2. Erosion at the inner wall of JET during the discharge campaign 2011–2012 in comparison with previous campaigns

    Energy Technology Data Exchange (ETDEWEB)

    Krat, S. [National Research Nuclear University “MEPhI”, Moscow Kashirskoe shosse 31, 115409 (Russian Federation); Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Gasparyan, Yu; Pisarev, A. [National Research Nuclear University “MEPhI”, Moscow Kashirskoe shosse 31, 115409 (Russian Federation); Bykov, I. [Fusion Plasma Physics, Royal Institute of Technology (KTH), Teknikringen 31, Stockholm 10044 (Sweden); Mayer, M., E-mail: matej.mayer@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Saint Aubin, G. de; Balden, M. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Lungu, C.P. [NILPRP, Association EURATOM-MEdC, Bucharest (Romania); Widdowson, A. [Culham Science Centre, EURATOM/UKAEA – Fusion Association, Abingdon, Oxfordshire OX14 3DB (United Kingdom)

    2015-01-15

    The erosion of Be and W marker layers was investigated using long-term samples during the first ITER-like wall discharge campaign 2011–2012. The markers were mounted in Be coated Inconel tiles between the inner wall guard limiters (IWGL). They were analyzed using Rutherford backscattering (RBS) before and after exposure. All samples showed strong erosion. The results were compared to the data for Be and W erosion rates for the 2005–2009 and the 2001–2004 campaigns, respectively, when JET was operated with a carbon wall. In 2005–2009 Be and C samples were used, and W samples were used in 2001–2004. The mean W erosion rates and the toroidal and poloidal distributions of the W erosion were the same for the 2001–2004 and the 2011–2012 campaigns. The mean erosion rate of Be during the 2011–2012 campaign was smaller by a factor of about two compared to the 2005–2009 campaign and showed a different poloidal distribution. The mean erosion rate of the inner JET ITER-like wall was about 4–5 times smaller than the mean erosion rate of the carbon wall.

  3. Comparison of epicardial adipose tissue (EAT) thickness and anthropometric measurements in metabolic syndrome (MS) cases above and under the age of 65.

    Science.gov (United States)

    Karadag, Berrin; Ozulu, Banu; Ozturk, Feyza Yener; Oztekin, Erkan; Sener, Nur; Altuntas, Yuksel

    2011-01-01

    EAT is a new index of cardiac and visceral obesity. Waist circumference (WC) measurement is not fully reliable in the determination of visceral adipose tissue (VAT), especially in elderly individuals. Studies on the reflection of the intra-abdominal fat mass by the EAT mass surrounding the heart were performed. Our purpose in this study was to determine the relation between the MS criteria and EAT in MS cases and especially to compare anthropometric measures between non-geriatric patients under the age of 65, and geriatric ones over the age of 65 years. The study was performed during the years 2008 and 2009 on 120 cases; 66.7% of them were under the age of 65 and 33.3% of the cases were 65-year old or older. All of the patients were diagnosed as MS by the International Diabetes Federation (IDF) criteria. They were randomized as per the application order and included to the study. Each subject underwent transthoracic two-dimensional (2D) guided M-mode echocardiogram. We measured epicardial fat thickness on the 1/3 section close to the ventricle basis adjacent to the free wall of right ventricle from both the parasternal long axis (LA) and parasternal short axis (SA) views. Multiple regression analysis showed that WC, systolic blood pressure (SBP) and age were the strongest independent variables correlated with EAT (pEAT (pEAT-measurement by echocardiography is an efficient method in determination of visceral adiposity and shall be taken into consideration especially when advanced age groups are in question.

  4. A comparison between powders and thin films of single-walled carbon nanotubes for the adsorption behaviors of phenylalanine and glycine by XANES study

    Institute of Scientific and Technical Information of China (English)

    IBRAHIM; Kurash

    2010-01-01

    We have compared the adsorption behaviors between single-walled carbon nanotube (SWCNT) powders and thin films with amino acids such as phenylalanine and glycine by using the X-ray absorption near edge structure (XANES) spectroscopy. On SWCNT powders very weak adsorption occurs as confirmed also by studies at high solution concentrations. The comparison of the adsorption behaviors with previous reports for thin films of SWCNTs shows that, due to their compact structure, thin films favor the adsorption of amino acids and represent themselves good candidate for a reliable evaluation of the interaction among amino acids and SWCNTs.

  5. Postmastectomy radiotherapy of the chest wall. Comparison of electron-rotation technique and common tangential photon fields

    Energy Technology Data Exchange (ETDEWEB)

    Hehr, T.; Classen, J.; Huth, M.; Durst, I.; Bamberg, M.; Budach, W. [Dept. of Radiation Oncology, Univ. of Tuebingen, Tuebingen (Germany); Christ, G. [Dept. of Medical Physics, Univ. of Tuebingen, Tuebingen (Germany)

    2004-10-01

    Background and purpose: different radiotherapy techniques are being used for postmastectomy irradiation. A retrospective analysis of patterns of locoregional failure (LRF) after modified radical mastectomy and axillary lymph node dissection followed by locoregional radiotherapy with or without systemic treatment was performed. Main emphasis was focused on the comparison of two postmastectomy radiotherapy techniques. Patients and methods: 287 evaluable patients with locally advanced disease and/or adverse pathologic features (pT3 17% of patients, pT4 35%, multicentricity 25%, pN more than three positive nodes and/or pN1biii 70%, ''close margins'' 29%, infiltration of pectoral fascia 20%) with or without adjuvant chemo-hormonal treatment were included between 1989 and 2000. Median age was 61 years (range 24-88 years). All patients had modified radical mastectomy and axillary lymphonodectomy level I-II(III) for primary breast cancer. Median total dose of conventionally fractionated radiotherapy to the chest wall was 50 Gy (range 46-56 Gy). A local boost to the tumor bed of 10 Gy was applied in 72 patients. 80% of the patients received supraclavicular and 60% ipsilateral internal mammary lymph node irradiation of 50 Gy. 19% of the patients received adjuvant chemo-hormonal therapy, 38% hormonal therapy, and 27% chemotherapy. The median follow-up of patients at risk was 43 months (average 54 months). Results: the 5-year locoregional tumor control (LRC), LRC first event, disease-free, and overall survival were 85%, 91%, 61%, and 70% (Kaplan-Meier analysis), respectively. Cox regression analysis showed that stage III (relative risk [RR] 1.7), more than three involved axillary lymph nodes (RR 5.1), and infiltration of the pectoral fascia (RR 3.2) increased the risk of locoregional failure, while positive estrogen receptor status (RR 0.3) was associated with a reduced risk. No statistically significant differences in LRC were observed for patients treated

  6. Thin Wall Austempered Ductile Iron (TWADI

    Directory of Open Access Journals (Sweden)

    M. Górny

    2009-07-01

    Full Text Available In this paper the analysis of thin walled castings made of ductile iron is considered. It is shown that thin wall austempered ductile iron can be obtained by means of short-term heat treatment of thin wall castings without addition of alloying elements. Metallographic examinations of 2 mm thin walled castings along with casting with thicker wall thickness (20x28 mm after different austempring conditions are presented. It has been proved that short-term heat treatment amounted 20 minutes of austenitizing at 880 oC followed by holding at 400 oC for 5 minutes causes ausferrite matrix in 2 mm wall thickness castings, while casting with thicker wall thickness remain untransformed and martensite is still present in a matrix. Finally there are shown that thin wall ductile iron is an excellent base material for austempering heat treatments. As a result high mechanical properties received in thin wall plates made of austempered ductile iron.

  7. Modelling of URM Walls Retrofitted with Cable:A Comparison Between a Basic Mechanical Model and Distinct Element Method

    Institute of Scientific and Technical Information of China (English)

    ZHUGE Yan; CHUANG Shihwei

    2006-01-01

    The Australian love of "heritage" buildings (most of them are unreinforced masonry (URM)) means that greater attention is required to secure their performance under seismic or impact loading in the future.A research project has been carried out to develop a new,economic and high strength retrofitting technique for masonry structures.A series of experimental testing on URM walls retrofitted with an innovative technique by cable system have been conducted.In this paper,an analytical model which is based on distinct element method(DEM) is developed to simulate the behaviour of retrofitted walls.In DEM,a solid is represented as an assembly of discrete blocks.Joints are modelled as interface between distinct bodies.It is a dynamic process and specially designed to model the behaviour of discontinuities.In order to assist the practising engineers to design this new retrofitted wall system,a simple mechanical model was also developed to predict the strength of the retrofitted walls.The results obtained from this simple mechanical model are compared with those from both experiments and distinct element model.

  8. Haemodynamics of giant cerebral aneurysm: A comparison between the rigid-wall, one-way and two-way FSI models

    Science.gov (United States)

    Khe, A. K.; Cherevko, A. A.; Chupakhin, A. P.; Bobkova, M. S.; Krivoshapkin, A. L.; Orlov, K. Yu

    2016-06-01

    In this paper a computer simulation of a blood flow in cerebral vessels with a giant saccular aneurysm at the bifurcation of the basilar artery is performed. The modelling is based on patient-specific clinical data (both flow domain geometry and boundary conditions for the inlets and outlets). The hydrodynamic and mechanical parameters are calculated in the frameworks of three models: rigid-wall assumption, one-way FSI approach, and full (two-way) hydroelastic model. A comparison of the numerical solutions shows that mutual fluid- solid interaction can result in qualitative changes in the structure of the fluid flow. Other characteristics of the flow (pressure, stress, strain and displacement) qualitatively agree with each other in different approaches. However, the quantitative comparison shows that accounting for the flow-vessel interaction, in general, decreases the absolute values of these parameters. Solving of the hydroelasticity problem gives a more detailed solution at a cost of highly increased computational time.

  9. The comparison of GEANT 4.8.2 and 4.9.2 results for the 25MeV protons in thick polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Yevseyeva, Olga; Assis, Joaquim T. de; Ievsieieva, Ievgeniia [Universidade Estadual do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Instituto Politecnico; Evseev, Ivan G.; Schelin, Hugo R.; Ahmann, Francielle; Paschuk, Sergei A.; Milhoretto, Edney [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Diaz, Katherin S. [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear, Havana (Cuba); Hormaza, Joel M. [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Instituto de Biociencias; Lopes, Ricardo T. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear

    2011-07-01

    Full text: The fidelity of Monte Carlo simulations is crucial, especially if for medical applications. Our earlier study has shown that the GEANT4 simulations of proton energy spectra after thick absorbers do not agree well with existing experimental data. Moreover, the spectra simulated for the Bethe-Bloch domain were showing an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 up to version 8.2 during our previous simulations for proton Computerized Tomography (pCT). As one of the probable reasons for these effects could be some specific feature in the code, or some specific implicit parameters in the GEANT4 manual, we have decided to continue our observations, but this time - with version 4.9.2 of the GEANT. This work describes in details the new simulations for 25 MeV protons passing through 6mm polyethylene absorber. As in our previous simulations, we have started from the Hadron therapy Example of GEANT4 official release by adjusting the geometry only. We have tested all available choices of the Electromagnetic Physics Models. The results are compared with our previous GEANT4, TRIM/SRIM and MCNPX simulations, with theoretical predictions and with experimental data. Some variations in comparison with our previous results were obtained. (author)

  10. Comparison between results of detailed tectonic studies on borehole core vs microresistivity images of borehole wall from gas-bearing shale complexes, Baltic Basin, Poland.

    Science.gov (United States)

    Bobek, Kinga; Jarosiński, Marek; Pachytel, Radomir

    2017-04-01

    , cemented with calcite, were clearly visible in scanner image. We have also observed significantly lower density of veins in core than in the XRMI that occurs systematically in one formation enriched with carbonate and dolomite. In this case, veins are not fractured in core and obliterated for bare eye by dolomitization, but are still contrastive in respect of electric resistance. Calculated density of bedding planes per 1 meter reveals systematically higher density of fractures observed on core than in the XRMI (depicted automatically by interpretation program). This difference may come from additional fracking due to relaxation of borehole core while recovery. Comparison of vertical joint fractures density with thickness of mechanical beds shows either lack of significant trends or a negative correlation (greater density of bedding fractures correspond to lower density of joints). This result, obtained for shale complexes contradict that derived for sandstone or limestone. Boundary between CLUs are visible on both: joint and bedding fracture density profiles. Considering small-scale faults and slickensides we have obtained good agreement between results of core and scanner interpretation. This study in the frame of ShaleMech Project funded by Polish Committee for Scientific Research is in progress and the results are preliminary.

  11. Application and comparison of four selected procedures for the isolation of cell-wall material from the skin of grapes cv. Monastrell

    Energy Technology Data Exchange (ETDEWEB)

    Apolinar-Valiente, R., E-mail: tokay04@hotmail.com [Departamento de Tecnologia de Alimentos, Nutricion y Bromatologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Romero-Cascales, I., E-mail: miromero@um.es [Departamento de Tecnologia de Alimentos, Nutricion y Bromatologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Lopez-Roca, J.M., E-mail: jmlroca@um.es [Departamento de Tecnologia de Alimentos, Nutricion y Bromatologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Gomez-Plaza, E., E-mail: encarnag@um.es [Departamento de Tecnologia de Alimentos, Nutricion y Bromatologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Ros-Garcia, J.M., E-mail: jmros@um.es [Departamento de Tecnologia de Alimentos, Nutricion y Bromatologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain)

    2010-02-15

    In order to choose an appropriate cell-wall material (CWM) isolation procedure in grapes cv. Monastrell, four different standard procedures have been tested, and a comparison made of the amount of cell-wall material obtained, its composition and morphology. The CWM was isolated as the 70% ethanol insoluble residue (de Vries method), as the absolute ethanol insoluble residue filtered sequentially through nylon mesh (Nunan method), as the insoluble residue in sodium deoxycholate-phenol-acetic acid-water (Selvendran method) and as the N-[2-hydroxyethyl]-piperazine-N'-2-ethanesulfonic acid (HEPES) insoluble residue (Vidal method). All extractions were done in triplicate and the efficiency of the extractive procedure established. Carbohydrates, proteins, and phenolic compounds were analysed, as the main constituents of CWM. The morphology of the isolated CWM was visualized by scanning electron microscopy (SEM). The Selvendran method had the highest efficiency, while the Nunan method had the lower one. Regarding the carbohydrates composition, the four different CWM were rich in uronic acids and glucose, together with varying amounts of arabinose, xylose, mannose and galactose. The Selvendran method had the lower value of total carbohydrates and the CWM shows more plasmatic membrane impurities in SEM images. The chemical results of the Vidal and de Vries methods were quite similar, but the Vidal method was more time consuming than the de Vries method. According to the results, the de Vries method was chosen to produce a representative cell-wall material fraction from Monastrell grapes skin.

  12. Numerical Simulation of Non-isothermal Jetinto Crossflow for T-junction Pipe with Thick Wall%厚壁三通管件非等温横向射流的数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    吴海玲; 陈听宽; 罗毓珊; 毛庆; 张毅雄

    2001-01-01

    为了研究压水堆核电站冷却剂系统中厚壁三通管件的热应力问题,模拟了速度比分别为0.05和0.5条件下的非等温横向射流,并通过固体区域与流体区域的耦合传热计算,获得了厚壁管件的温度分布。计算基于有限容积法,采用k-ε紊流模型,计算结果与实验吻合良好。通过研究低流速比横向射流的流动和传热特性,从流动机理上考察了流动结构对构件温度分布及热应力的影响,指出在实际运行中可能对厚壁三通管件产生热冲击,从而引起构件热疲劳破坏的主要因素。定性地讨论了不同流速比下构件承受的热冲击状况,为运行参数及构件的优化设计提供了理论依据。%The present work is to investigate the three-dimensional non-isothermal turbulent jet into crossflow in a thick-wall T-junction pipe, which is commonly subject to the greatest thermal stress in the pressurized water reactor (PWR) cooling system. Two cases with low jet-to-crossflow velocity ratios of 0.05 and 0. 5 are computed, with a finite-volume numerical procedure utilizing k-ε turbulent model. Temperature of the pipe is acquired by thermally coupling with the fluid. Compariso of the computations with measured data shows good qualitative agreement. Via analysis of the flow and thermal characteristics, influence of the flow structure on the temperature distribution and thermal stress of the component is studied. Major factors causing instantaneous thermal shock of the component are explored. Optimal flow rates are discussed to reduce the thermal stress.

  13. Consistence study of carotid artery wall thickness by MDCTA and high-frequency ultrasound%MDCTA与高频超声检测颈动脉壁厚度的一致性研究

    Institute of Scientific and Technical Information of China (English)

    洪玮; 赵刚; 王弘; 邱晓明; 王珍

    2012-01-01

    Objective To explore the relevance and consistence between multi-detector row computed tomography angi-ography (MDCTA) and high-frequency ultrasound in measuring carotid artery wall thickness (CAWT) and the intima-media thickness (IMT). Methods Altogether, 64 subjects were prospectively analysed using a 64-detector row CT and high-frequency ultrasound. And they were classified as non-plaque group and plaque group. CAWT and IMT were measured in each patient using MDCTA and ultrasound, respectively. CAWT and IMT were compared and dependency analysed. Bland-Altman statistics was employed to measure the consistency between MDCTA and ultrasound. Results There was not significant difference between CAWT and IMT in the same group ( P > 0. 05). There was a high degree of correlation between all the common carotid artery CAWT and IMT, correlation coefficient was 0. 912 ( P <0. 01). By analysing the Bland-Altman plot, we observed a good consistence between CAWT and IMT with a bias between methods of 0. 029 mm and limit of consistence from 0. 187 mm to 0. 244 mm. Conclusion There was a good consistency between MDCTA and high-frequency ultrasound in the measurement of CAWT and IMT. CAWT can be used as an evaluating indicator of carotid atherosclerosis by MDCTA.%目的 探讨多层螺旋CT血管造影(MDCTA)检测颈总动脉壁厚度(CAWT)与高频超声检测颈总动脉内-中膜层厚度(IMT)的相关性和一致性.方法 应用MDCTA和高频超声对64例患者颈总动脉CAWT和IMT分别进行扫描,分为无斑块组和有斑块组,统计学比较CAWT与IMT的差异性和相关性,用Bland-Altman分析比较两者的一致性.结果 两组患者颈总动脉CAWT与IMT比较无统计学差异(P>0.05),相关性分析呈高度正相关,相关系数为0.912(P<0.O1),Bland-Altman分析存在较好一致性,偏倚为0.029mm,一致性界限为0.187~0.244mm.结论 MDCTA测量颈总动脉CAWT与高频超声测量颈总动脉IMT之间存在高度相关性和较好一致

  14. Numerical Simulation of Residual Stress Distributions in Plasma-Sprayed Coating on Thick Wall Component%基于Nastran等离子喷涂厚壁零件涂层中残余应力分析

    Institute of Scientific and Technical Information of China (English)

    牛丽萍; 张延安; 史冠勇; 赫冀成

    2012-01-01

    The residual stress distributions in the plasma sprayed coatings on thick wall component were modeled and numerically simulated in finite element method, based on the software package Nastran. The impacts of the coating conditions, including the species of the coating and substrate, I. E. Ceramic or metal, on the residual stress were evaluated. The simulated results show that the strongest stress distribution exists at the coating/substrate interface, increasing in the radial direction and peaking at the edges; and that the normal stress in the central area of the substrate decreases with an increase in substrate depth, and linearly distributes in the coating. Various key factors, including the dimensionless equation of radial stress, shear stress, maximum stain and immersion depth of the residual stress in the coating, were determined . The results, calculated with the dimensionless equation, agree fairly well with the simulated ones in all the coating/ substrate systems of interest. The influence of various factors, such as the thickness and elastic modulus of the coating, and the radius and modulus of the substrates, on the variations in the residual stress distributions was also tentatively discussed.%基于有限元数值分析对等离子喷涂不同的基体上的喷涂陶瓷涂层和金属涂层中残余应力进行了分析,结果表明:涂层与基体体系的最大应力分布在接触界面附近,由中心线向外依次递增,在边缘处达到最大值.在体系中心区域正应力沿厚度方向逐渐减小,而在涂层中应力分布则趋于线性;建立了涂层中各残余应力分量的准数方程式,准数方程式与数值计算结果显示了较好的吻合,而且对于不同基体-涂层体系均是适用的.无因次最大径向应变、无因次剪应力侵入深度和无因次最大径向应力的大小均取决于涂层厚度与弹性模量的积和基体半径与基体弹性模量积之间比值,而影响无因次径向最大剪应

  15. Left ventricular wall stress compendium.

    Science.gov (United States)

    Zhong, L; Ghista, D N; Tan, R S

    2012-01-01

    Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models.

  16. Comparison of conventional inserts and an add-on electron MLC for chest wall irradiation of left-sided breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Vatanen, Tero; Lahtinen, Tapani (Dept. of Oncology, Kuopio Univ. Hospital, Kuopio (Finland)); Traneus, Erik (Nucletron Scandinavia AB, Uppsala (Sweden))

    2009-04-15

    Background. Collimation of irregularly shaped clinical electron beams is currently based on electron inserts made of low melting point alloys. The present investigation compares a conventional electron applicator with insert and add-on eMLC-based dose distributions in the postoperative chest wall irradiation of left-sided breast cancer. Material and methods. Voxel Monte Carlo++ (VMC++) calculated dose distributions related to electron fields were compared with 10 left-sided breast cancer patients after radical mastectomy. The prescription dose was 50 Gy at a build-up maximum. The same dose was prescribed for the ipsilateral axillary, parasternal and supraclavicular lymph nodes that were treated with photons and calculated with a pencil beam algorithm. The insert beams were shaped with 1.5 cm thick Wood's metal electron inserts in an electron applicator of a Varian 2100 C/D linac. Doses for the eMLC-shaped beams were calculated for an eMLC prototype with 2 cm thick and 5 mm wide steel leaves. The same collimator-to-surface distance (CSD) of 5.8 cm was used for both collimators. Results. The mean PTV dose was slightly higher for the eMLC plans (50.7 vs 49.5 Gy, p<0.001, respectively). The maximum doses assessed by D5% for the eMLC and insert were 60.9 and 59.1 Gy (p<0.001). The difference was due to the slightly higher doses near the field edges for the eMLC. The left lung V20 volumes were 34.5% and 34.0% (p<0.001). There was only a marginal difference in heart doses. Discussion: Despite a slight increase of maximum dose in PTV the add-on electron MLC for chest wall irradiation results in practically no differences in dose distributions compared with the present insert-based collimation.

  17. Analytical 1D models of the wall thermal resistance of rectangular minichannels applied in heat exchangers

    Directory of Open Access Journals (Sweden)

    Rybiński Witold

    2016-09-01

    Full Text Available The paper presents four 1-dimensional models of thermal resistance of walls in a heat exchanger with rectangular minichannels. The first model is the simplest one, with a single wall separating two fluids. The second model of the so called equivalent wall takes into account total volume of intermediate walls between layers of minichannels and of side walls of minichannels. The next two more complicated models take separately into account thermal resistance of these walls. In these two models side walls are treated as fins. The results of models comparison are presented. It is shown that thermal resistance may be neglected for metal walls but it should be taken into account for the walls made of plastics. For the case of non-neglected wall thermal resistance the optimum wall thickness was derived. Minichannel heat exchangers made of plastic are larger than those built of metal, but are significantly cheaper. It makes possible to use of such exchangers in inexpensive microscale ORC installations.

  18. SU-E-T-18: A Comparison of Planning Techniques for Bilateral Reconstructed Chest Wall Patients Undergoing Whole Breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Volpe, T; Margiasso, R; Saleh, Z; Kuo, L; Hong, L; Ballangrud, A; Gelblum, D; Zinovoy, M; Deasy, J; Tang, X [Memorial Sloan Kettering Cancer Center, New York, NY (United States)

    2015-06-15

    Purpose: As we continuously see more bilateral reconstructed chest wall cases, new challenges are being presented to deliver left-sided breast irradiation. We herein compare three Deep Inspiration Breath Hold (DIBH) planning techniques (tangents, VMAT, and IMRT) and two free breathing techniques (VMAT and IMRT). Methods: Three left-sided chest wall patients with bilateral implants were studied. Tangents, VMAT, and IMRT plans were created for DIBH scans. VMAT and IMRT plans were created for free breathing scans. All plans were normalized so that 95% of the prescription dose was delivered to 95% of the planning target volume (PTV). The maximum point dose was constrained to less than 120% of the prescription dose. Since the success of DIBH delivery largely depends on patient’s ability to perform consistent breath hold during beam on time, smaller number of Monitor Units (MU) is in general desired. For each patient, the following information was collected to compare the planning techniques: heart mean dose, left and right lung V20 Gy, contra-lateral (right) breast mean dose, cord max dose, and MU. Results: The average heart mean dose over all patients are 1561, 692, 985, 1245, and 1121 cGy, for DIBH tangents, VMAT, IMRT, free breathing VMAT and IMRT, respectively. For left lung V20 are 60%, 28%, 26%, 30%, and 29%. For contra-lateral breast mean dose are 244, 687, 616, 783, 438 cGy. MU are 253, 853, 2048, 1035, and 1874 MUs. Conclusion: In the setting of bilateral chest wall reconstruction, opposed tangent beams cannot consistently achieve desired heart and left lung sparing. DIBH consistently achieves better healthy tissue sparing. VMAT appears to be preferential to IMRT for planning and delivering radiation to patients with bilaterally reconstructed chest walls being treated with DIBH.

  19. Comparison between methods using copper, lanthanum, and colorimetry for the determination of the cation exchange capacity of plant cell walls.

    Science.gov (United States)

    Wehr, J Bernhard; Blamey, F Pax C; Menzies, Neal W

    2010-04-28

    The determination of the cation exchange capacity (CEC) of plant cell walls is important for many physiological studies. We describe the determination of cell wall CEC by cation binding, using either copper (Cu) or lanthanum (La) ions, and by colorimetry. Both cations are strongly bound by cell walls, permitting fast and reproducible determinations of the CEC of small samples. However, the dye binding methods using two cationic dyes, Methylene Blue and Toluidine Blue, overestimated the CEC several-fold. Column and centrifugation methods are proposed for CEC determination by Cu or La binding; both provide similar results. The column method involves packing plant material (2-10 mg dry mass) in a chromatography column (10 mL) and percolating with 20 bed volumes of 1 mM La or Cu solution, followed by washing with deionized water. The centrifugation method uses a suspension of plant material (1-2 mL) that is centrifuged, and the pellet is mixed three times with 10 pellet volumes of 1 mM La or Cu solution followed by centrifugation and final washing with deionized water. In both methods the amount of La or Cu bound to the material was determined by spectroscopic methods.

  20. Patients with Cushing's syndrome have increased intimal media thickness at different vascular levels: comparison with a population matched for similar cardiovascular risk factors.

    Science.gov (United States)

    Albiger, N; Testa, R M; Almoto, B; Ferrari, M; Bilora, F; Petrobelli, F; Pagnan, A; Mantero, F; Scaroni, C

    2006-06-01

    Cushing's syndrome (CS) is associated with high cardiovascular risk. The aim of this study was to analyze intimal media thickness (IMT) in patients with CS and compare them with subjects matched for similar conventional and independent cardiovascular risk factors. Twenty eight patients with CS (mean age: 40.7 +/- 2.5 y) and 28 subjects (mean age: 41.1 +/- 14 y) matched for sex, age, smoking habit, body mass index, blood pressure levels, glucose and lipid metabolism were evaluated. IMT was measured at right and left common carotid (CC), carotid bulb (BC), aorta (Ao) and femoral (F) levels by B-echo-Doppler ultrasonography. Although parameters of cardiovascular risk factors did not differ statistically between patients and controls, IMT was significantly increased (right and left CC-IMT, p < 0.05; right and left BC-IMT, p < 0.01, Ao-IMT p < 0.05) and wall plaques were more common (14.2 % VS. 7.1 %) in patients. In CS patients, CC-IMT and F-IMT correlated positively and significantly with fasting glucose (right CC-IMT: r (2) = 0.37, p = 0.05; left CC-IMT: r (2) = 0.43, p = 0.02; right F-IMT: r (2) = 0.57; p < 0.01; left F-IMT: r (2) = 0.47, p = 0.01) and HOMA index (left CC-IMT: r (2) = 0.64, p < 0.01 and left F-IMT: r (2) = 0.48, p < 0.05). The CS patients' waist-to-hip ratio (WHR) was evaluated and correlated positively and significantly with CC-IMT (right: r (2) = 0.53, p = 0.01 and left: r (2) = 0.44, p = 0.05). No correlation was found between IMT and cortisol levels, however. In conclusion, patients with CS have more severe atherosclerotic damage than a population matched for similar cardiovascular risk factors. Multiple events related to long-term cortisol effects on metabolism and at vascular and endothelial sites may increase the risk of cardiovascular damage in patients with CS.

  1. CFD-DEM study of effect of bed thickness for bubbling fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Tingwen, Li; Gopalakrishnan, Pradeep; Garg, Rahul; Shahnam, Mehrdad

    2011-10-01

    The effect of bed thickness in rectangular fluidized beds is investigated through the CFD–DEM simulations of small-scale systems. Numerical results are compared for bubbling fluidized beds of various bed thicknesses with respect to particle packing, bed expansion, bubble behavior, solids velocities, and particle kinetic energy. Good two-dimensional (2D) flow behavior is observed in the bed having a thickness of up to 20 particle diameters. However, a strong three-dimensional (3D) flow behavior is observed in beds with a thickness of 40 particle diameters, indicating the transition from 2D flow to 3D flow within the range of 20–40 particle diameters. Comparison of velocity profiles near the walls and at the center of the bed shows significant impact of the front and back walls on the flow hydrodynamics of pseudo-2D fluidized beds. Hence, for quantitative comparison with experiments in pseudo-2D columns, the effect of walls has to be accounted for in numerical simulations.

  2. Relation between QT dispersion and regional wall thickness abnormality of ventricle in patients with acute myocardial infarction%急性心肌梗死患者QT离散度变化 与室壁厚度异常的关系

    Institute of Scientific and Technical Information of China (English)

    王兴德; 赵绮芳; 刘珂

    2001-01-01

    目的 观察急性心肌梗死(AMI)患者QT间期离散度变化与室壁厚度异常的关系。方法 观察35例AMI患者和31例劳力型心绞痛患者QT离散度与室壁收缩厚度改变百分率的变化。结果 (1)AMI后第1天、第4周的QTd值较对照组明显延长。对照组和AMI组区域性收缩厚度改变百分率之间差异有显著性(t=6.77,P<0.01)。(2)AMI后第1天和第4周QTd值与区域性收缩厚度改变百分率呈显著负相关(r=-0.85,r=-0.72,P值均<0.01)。结论 AMI后QTcd显著延长,并与收缩时室壁厚度改变密切相关。%Objective To explore the relation between increased QT dispersion (QTcd) and regional wall thickness change abnormality in patients with acute myocardial infarction(AMI).Methods The QTcd and the wall thickness change in systole in 35 patients of early AMI and in 31 cases of exertional angina(control group) were measured.Results 1.The QTcd in AMI group was longer than those in control group.There had significant difference of regional wall thickness change percent in systole between AMI group and the control group(P<0.01). 2. The QTcd of AMI group had significantly negative correlation with the region wall thickness change percent in systole(P<0.01).Conclusion The results showed that the QTcd in early AMI is longer than in exertional angina and the QTcd change is closely correlation with the wall thickness change in systole.

  3. Thermal transmittance of reed-insulated walls in a purpose-built test house

    Directory of Open Access Journals (Sweden)

    M. Miljan

    2014-03-01

    Full Text Available We studied the construction and thermal properties of walls insulated with reed, to enable comparisons with other wall structures that are widely used in building. In 2010 we built a test house insulated with reed adjacent to the Estonian University of Life Sciences in Tartu. The load-bearing structure of the house was a timber frame, and four different technologies were used to place reed insulation in its external walls. The thickness of the reed layer was 450 mm in all cases, and both sides (inside and outside of the walls were rendered with clay plaster. Records were kept of time spent and materials used in construction of the different types of walls, and these data were used to calculate unit (m-2 requirements of time and materials for each wall type to enable direct comparisons. From October 2010 to March 2012, heat flow plates were used to measure the thermal transmittance of the walls of the completed house and the results were compared with the thermal transmittance requirements set by Estonian legislation. Only one of the test walls met the Estonian standard. This was insulated with compressed loose reed, placed horizontally in the wall.

  4. Falling parts of external walls claddings in case of fire – ITB test method – results comparison

    Directory of Open Access Journals (Sweden)

    Kinowski Jacek

    2016-01-01

    Full Text Available Paper presents ITB methodology of testing and assessment of buildings with regard to falling of external walls claddings in case of fire. In the ITB methodology of impact on the facade (external claddings was assumed in form of flames, generated from a specially designed propane, sand burner with a defined fuel flow rate and laminar airflow from the inside of the furnace resulting in determined temperature and height of the flame. Evaluated criterion is also discussed. Test results of several different types of claddings is analysed and presented in relation to the national Polish regulation along with some technical assessment regarding individual.

  5. Comparison of retinal nerve fiber layer and macular thickness measurements with Stratus OCT and OPKO/OTI OCT devices in healthy subjects

    Institute of Scientific and Technical Information of China (English)

    Ahmet; Ozkok; Julide; Canan; Umurhan; Akkan; Nevbahar; Tamcelik; Mehmet; Erdogan; Didar; Ucar; Comlekoglu; Rengin; Yildirim

    2015-01-01

    AIM: To compare retinal nerve fiber layer(RNFL) and macular thickness measurements obtained with the Stratus optical coherence tomography(OCT) and OPKO/OTI OCT devices.METHODS: Included in the study were 59 eyes of 30 participants. All measurements for each eye were done on the same day with both devices. Student’s paired t-tests were used to compare the central macular thickness and RNFL measurements of the Stratus OCT and OPKO/OTI OCT. Pearson correlation was used to assess the relationship between the devices. Coefficient of variation(COV) was calculated to assess intersession repeatability.RESULTS: Using both the Stratus OCT and OPKO/OTI OCT, respectively, the measured mean average RNFL thicknesses were 98.9±11.1 μm and 115.1±9.6 μm(P =0.001),and the measured mean central retinal thicknesses(CRT)were 196.2 ±18.8 μm and 204.5 ±21.1 μm(P <0.001).Measured by the two devices, the RNFL thickness values were correlated in all quadrants, as were the retinal thickness values except the inferior outer sector. COV for average RNFL and CRT thickness were 2.9% and 4.6%for Stratus OCT, and 2.1% and 4.2% for OPKO/OTI OCT,respectively.CONCLUSION: We found good reproducibility of RNFL and retina thickness measurements for both Stratus OCT and OPKO/OTI OCT devices. However, even though the two OCT systems provided statistically correlated results,the values for both RNFL and macular thickness were statistically different. RNFL and macular thickness measurements with the OPKO/OTI OCT were higher than that of the Stratus OCT; there