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Sample records for sand-silicone thickness ratio

  1. Formability of Friction Stir-Welded Blanks with Different Thickness Ratios

    Science.gov (United States)

    Kolahgar, Sina; Ghaffarpour, Morteza; Habibi, Niloufar; Kokabi, Amir Hossein; Akbarzadeh, Abbas

    2016-05-01

    Welded sheets with different thicknesses are one of the interesting types of tailor-welded blanks (TWBs) that are widely used in metal-forming industries. In the present work, the formability behavior of different 1100-aluminum TWBs was studied. In this regard, the TWBs were made with different thickness ratios by using friction stir welding (FSW) at different welding rotational speeds ( ω). The thickness ratios of 1.0, 1.3, and 1.7 were investigated where the thinner sheets had 1.5 mm thick for all conditions; i.e., the volume of welded material increased when the thickness ratio increased. Macrostructural observations, mechanical investigations, and sheet-forming limit tests were conducted. The results indicate that increasing ω leads to increasing the weld nugget size up to a maximum level and welding became impossible at higher ω. Furthermore, increasing heat input during FSW, the ultimate tensile strength of welds reduced in comparison with the initial cold-worked base metal. However, the ductility improved by increasing the heat input, which produced the sound welds. Formability studies of the friction stir-welded blanks with equal thicknesses have shown that the forming ratio improves up to 2.8 times the base metal. Forming limit curves also illustrate that increasing the thickness ratio of TWB causes the formability ratio to decrease steadily. Thus, when the thickness ratio becomes 1.7, the formability of TWB decreases approximately to the thinnest base metal.

  2. Thickness ratio and d 33 effects on flexible piezoelectric unimorph energy conversion

    Science.gov (United States)

    Ha, Taewoo; Zhang, John X. J.; Lu, Nanshu

    2016-03-01

    Piezoelectric unimorphs are bilayer structures where a blanket piezoelectric film (with top and bottom electrodes) is uniformly laminated on an inactive but flexible substrate. Because of their simple construction and flexibility, unimorphs are widely used as a key element in flexible sensors and actuators. The response of a unimorph is governed by the material properties of the film and the substrate as well as their geometric parameters. For low frequency biological energy harvesting, structural optimization is critical due to the dimensional confinement imposed by curvilinear and deformable bio-tissues. Here we report a comprehensive theoretical framework to investigate the effects of the film-to-substrate thickness ratio on voltage, charge, and energy outputs when the unimorph is subjected to eight different boundary/loading conditions. A broad class of power generators can be designed using such a framework under the assumption that the unimorph length is very large compared to its thickness, where the only dimensionless variable is the film-to-substrate thickness ratio. We show that the analytical and finite element modeling results are in excellent agreement. For not so thin unimorphs, there is non-zero normal stress in the thickness direction (σ 3) and d 33 can play a significant role in this case. Non-monotonic dependence of voltage and energy generation on thickness ratio has been found in some cases and optimum thickness ratio for unimorph generator can be predicted. When the unimorph is actuated by voltage applied across the piezo-film thickness, non-monotonic maximum deflection versus thickness ratio is also found. This work provides new physical insights on unimorphs and analytical solutions that can be used for the structural design and optimization of unimorphs under different boundary/loading conditions.

  3. Nasal bone length, prenasal thickness, prenasal thickness-to-nasal bone length ratio and prefrontal space ratio in second- and third-trimester fetuses with Down syndrome.

    Science.gov (United States)

    Vos, F I; De Jong-Pleij, E A P; Bakker, M; Tromp, E; Pajkrt, E; Kagan, K O; Bilardo, C M

    2015-02-01

    To evaluate nasal bone length (NBL), prenasal thickness (PT), prenasal thickness-to-nasal bone length (PT-NBL) ratio and prefrontal space ratio (PFSR) as markers for Down syndrome in the second and third trimesters. NBL, PT, PT-NBL ratio and PFSR were measured retrospectively in stored two-dimensional images or three-dimensional volumes (corrected to the mid-sagittal plane) of fetuses with Down syndrome, which were retrieved from the digital databases of participating units. Measurements were performed on the stored images and volumes by two experienced operators, and the values obtained were compared to our previously reported normal ranges for euploid fetuses in order to assess the detection rates for Down syndrome. A total of 159 fetuses with Down syndrome were included in the analysis, six of which were excluded because of inadequate available images. Median maternal age was 36.0 years and median gestational age was 23 + 1 weeks. NBL and PT were correlated with gestational age (P Down syndrome, the PT-NBL ratio yielded the highest detection rate (86.2%), followed by PFSR (79.7%), PT (63.4%) and NBL (61.9%). All markers were abnormal in 33.6% of cases, whilst all were normal in 4.7%. At least one of the four markers was abnormal in 95.3%, and either the PT-NBL ratio or PFSR was abnormal in 93.8%. Detection rates were not related to gestational age. The PT-NBL ratio and PFSR are robust second- and third-trimester markers for Down syndrome. Both provide high detection rates and are easy to use, as the cut-off for normality is constant throughout gestation. Ltd. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

  4. Chloride accelerated test: influence of silica fume, water/binder ratio and concrete cover thickness

    Directory of Open Access Journals (Sweden)

    E. Pereira

    Full Text Available In developed countries like the UK, France, Italy and Germany, it is estimated that spending on maintenance and repair is practically the same as investment in new constructions. Therefore, this paper aims to study different ways of interfering in the corrosion kinetic using an accelerated corrosion test - CAIM, that simulates the chloride attack. The three variables are: concrete cover thickness, use of silica fume and the water/binder ratio. It was found, by analysis of variance of the weight loss of the steel bars and chloride content in the concrete cover thickness, there is significant influence of the three variables. Also, the results indicate that the addition of silica fume is the path to improve the corrosion protection of low water/binder ratio concretes (like 0.4 and elevation of the concrete cover thickness is the most effective solution to increase protection of high water/binder ratio concrete (above 0.5.

  5. [The thickness/radius ratio (t/r) in patients with dilated and hypertrophic cardiomyopathy].

    Science.gov (United States)

    Guadalajara, J F; Valenzuela, F; Martínez Sánchez, C; Huerta, D

    1990-01-01

    We studied 17 patients with cardiomyopathy (10 hypertrophic and 7 dilated). With two-dimensional echocardiography, we obtained a short axis view at the level of papillary muscle. We calculated the ratio between thickness (h), of ventricular wall and cavity's radius (r) in diastole and systole (h/r ratio). Hypertrophic cardiomyopathy has a high h/r ratio in diastole (inappropriate hypertrophy), hypercontractility and low and systolic wall stress. Dilated cardiomyopathy has a low diastolic h/r ratio (inadequate hypertrophy) with low contractility and elevated end-systolic, wall stress. We discuss the mechanisms and consequences of different patterns of hypertrophy on the ventricular performance.

  6. Contrast ratio of veneering and core ceramics as a function of thickness.

    Science.gov (United States)

    Antonson, S A; Anusavice, K J

    2001-01-01

    The recent development of several dental ceramic products has raised questions concerning the relative translucency potential of these materials. The objective of this study was to test the hypothesis that the contrast ratio of dental core and veneering ceramics is a linear function of ceramic thickness. Four groups of disk-shaped core ceramic specimens and four groups of veneering ceramic specimens (15 mm in diameter and 0.70, 1.10, 1.25, or 1.50 mm in thickness) were prepared for analysis. Five disks were randomly assigned to each of the eight groups. Four core ceramics were selected for study: (1) tetrasilicic fluormica glass ceramic, (2) quadruple-chain silicate glass ceramic, (3) barium silicate glass ceramic, and (4) sintered alumina. The four veneering ceramics included two feldspathic body porcelains, one fine-grained veneering porcelain, and one ultralow-fusing porcelain. There were significant differences among the mean contrast ratio values of these materials. The most translucent group of the core materials was tetrasilicic fluormica glass ceramic, and the least translucent material was sintered alumina. The most translucent group among the veneering ceramics was one of the feldspathic ceramics (Ceramco), and the least translucent material for all thicknesses was the ultralow-fusing veneering ceramic (Duceram LFC). The mean contrast ratio values were significantly different at a thickness of 1.50 mm of the four core ceramic groups and among the four veneering ceramic groups. The results of this study indicate that the tetrasilicic fluormica glass ceramic is generally the most translucent core ceramic for thicknesses of 0.70, 1.10, and 1.25 mm, and Ceramco porcelain is the most translucent veneering ceramic. However, for a thickness of 1.50 mm, the quadruple-chain silicate glass ceramic was the most translucent core ceramic. The relationship between contrast ratio and thickness was linear for all ceramics except Vita VMK 68.

  7. Increased Hs-CRP/adiponectin ratio is associated with increase carotid intima-media thickness

    OpenAIRE

    Liao, Huocheng; Li, Zhiming; Zheng, Dongdan; Liu, Jianping; Liu, Yan; Xiao, Chun; Wang, Hongguang

    2014-01-01

    Background High sensitivity C-reactive protein (Hs-CRP) and adiponectin (APN) are two critical cytokines and exert inverse effects on atherosclerosis initiation and progression. The purpose of our study was to investigate the value of Hs-CRP and ANP ratio (Hs-CRP/APN ratio) on evaluating atherosclerosis progression. Method One hundred sixty consecutive participants underwent carotid intima-media thickness (CIMT) measured by ultrasound were enrolled and drawn fasting blood samples for plasma l...

  8. Correlation of Gear Surface Fatigue Lives to Lambda Ratio (Specific Film Thickness)

    Science.gov (United States)

    Krantz, Timothy Lewis

    2013-01-01

    The effect of the lubrication regime on gear performance has been recognized, qualitatively, for decades. Often the lubrication regime is characterized by the specific film thickness being the ratio of lubricant film thickness to the composite surface roughness. Three studies done at NASA to investigate gearing pitting life are revisited in this work. All tests were done at a common load. In one study, ground gears were tested using a variety of lubricants that included a range of viscosities, and therefore the gears operated with differing film thicknesses. In a second and third study, the performance of gears with ground teeth and superfinished teeth were assessed. Thicker oil films provided longer lives as did improved surface finish. These datasets were combined into a common dataset using the concept of specific film thickness. This unique dataset of more 258 tests provides gear designers with some qualitative information to make gear design decisions.

  9. Thickness dependence of the L{sub 2,3} branching ratio of Cr thin films

    Energy Technology Data Exchange (ETDEWEB)

    Aksoy, F. [Physics Department, University of Cukurova, 01330 Adana (Turkey); Physics Department, University of Nigde, 51100 Nigde (Turkey); Akguel, G. [Physics Department, University of Cukurova, 01330 Adana (Turkey); Ufuktepe, Y., E-mail: ufuk@cu.edu.t [Physics Department, University of Cukurova, 01330 Adana (Turkey); Nordlund, D. [Stanford Synchrotron Radiation Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2010-10-22

    We report the electronic structure of chromium (Cr) thin films depending on its thickness using two measures, total electron yield (TEY) and transmission yield mode. The Cr L edge X-ray absorption spectroscopy (XAS) spectrum shows strong thickness dependence with broader line widths observed for L{sub 2,3} edge peaks for thinner films. The white line ratio (L{sub 3}/L{sub 2}) was found to be 1.25 from the integrated area under each L{sub 3} and L{sub 2} peak and 1.36 from the ratio of the amplitudes of each L{sub 3} and L{sub 2} peak after the deconvolution. Additionally, we show that full-width at half-maximum (FWHM) at the L{sub 2} and L{sub 3} edges and the branching ratio of Cr change as a function of film thickness and these are discussed in detail. Using L{sub 2,3} resonance intensity variation as a function of film thickness we calculated the electron escape depth and X-ray attenuation length in Cr. Comparing our results with the literature, there was good agreement for the L{sub 3}-L{sub 2} ratio although the detailed shape can show additional solid state and atomic effects.

  10. Optimizing rib width to height and rib spacing to deck plate thickness ratios in orthotropic decks

    Directory of Open Access Journals (Sweden)

    Abdullah Fettahoglu

    2016-12-01

    Full Text Available Orthotropic decks are composed of deck plate, ribs, and cross-beams and are frequently used in industry to span long distances, due to their light structures and load carrying capacities. Trapezoidal ribs are broadly preferred as longitudinal stiffeners in design of orthotropic decks. They supply the required stiffness to the orthotropic deck in traffic direction. Trapezoidal ribs are chosen in industrial applications because of their high torsional and buckling rigidity, less material and welding needs. Rib width, height, spacing, thickness of deck plate are important parameters for designing of orthotropic decks. In the scope of this study, rib width to height and rib spacing to deck plate thickness ratios are assessed by means of the stresses developed under different ratios of these parameters. For this purpose a FE-model of orthotropic bridge is generated, which encompasses the entire bridge geometry and conforms to recommendations given in Eurocode 3 Part 2. Afterwards necessary FE-analyses are performed to reveal the stresses developed under different rib width to height and rib spacing to deck plate thickness ratios. Based on the results obtained in this study, recommendations regarding these ratios are provided for orthotropic steel decks occupying trapezoidal ribs.

  11. On the determination of Poisson's ratio of stressed monolayer and bilayer submicron thick films

    CERN Document Server

    Martins, P; Brida, S; Barbier, D

    2008-01-01

    In this paper, the bulge test is used to determine the mechanical properties of very thin dielectric membranes. Commonly, this experimental method permits to determine the residual stress (s0) and biaxial Young's modulus (E/(1-u)). Associating square and rectangular membranes with different length to width ratios, the Poisson's ratio (u) can also be determined. LPCVD Si3N4 monolayer and Si3N4/SiO2 bilayer membranes, with thicknesses down to 100 nm, have been characterized giving results in agreement with literature for Si3N4, E = 212 $\\pm$ 14 GPa, s0 = 420 $\\pm$ 8 and u = 0.29.

  12. The Effects of Smoking on Ultrasonographic Thickness and Elastosonographic Strain Ratio Measurements of Distal Femoral Cartilage.

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    Gungor, Harun R; Agladioglu, Kadir; Akkaya, Nuray; Akkaya, Semih; Ok, Nusret; Ozçakar, Levent

    2016-04-21

    Although adverse effects of smoking on bone health are all well known, data on how smoking interacts with cartilage structure in otherwise healthy individuals remains conflicting. Here, we ascertain the effects of cigarette smoking on sonoelastographic properties of distal femoral cartilage in asymptomatic adults. Demographic characteristics and smoking habits (packets/year) of healthy volunteers were recorded. Medial, intercondylar, and lateral distal femoral cartilage thicknesses and strain ratios on the dominant extremity were measured with ultrasonography (US) and real time US elastography. A total of 88 subjects (71 M, 17 F; aged 18-56 years, N = 43 smokers and N = 45 nonsmokers) were evaluated. Mean amount of cigarette smoking was 10.3 ± 8.9 (1-45) packets/year. Medial, intercondylar and lateral cartilage were thicker in smokers than nonsmokers (p = 0.002, p = 0.017, and p = 0.004, respectively). Medial distal femoral cartilage strain ratio was lower in smokers (p = 0.003). The amount of smoking was positively correlated with cartilage thicknesses and negatively correlated with medial cartilage strain ratios (p < 0.05). Femoral cartilage is thicker in smokers but has less strain ratio representing harder cartilage on the medial side. Future studies are needed to understand how these structural changes in the knee cartilage should be interpreted with regard to the development of knee osteoarthritis in smokers.

  13. Fatigue strength of bilayered ceramics under cyclic loading as a function of core veneer thickness ratios.

    Science.gov (United States)

    Dibner, Aurora Clark; Kelly, J Robert

    2016-03-01

    Minimal evidence is available concerning the appropriate thickness of each layer in bilayered ceramic systems. The purpose of this in vitro study was to examine the effect of core-veneer thickness ratios on the fatigue strength of a bonded bilayered ceramic system. Specimens of Ivoclar Porcelain System (IPS) e.max lithium disilicate were fabricated with core/veneer thicknesses of 0.5/1.0 mm, 0.75/0.75 mm, 1.0/0.5 mm, and 1.5/0.0 mm. All specimens were cemented to bases of a dentin-like material. Each specimen was cyclically loaded by a 2-mm-diameter G10 piston in water. Loads ranging from 10 N to the target load were applied at a frequency of 20 Hertz for 500,000 cycles. If cracked, the next specimen was cycled at a lower load; if not cracked, at a higher load (step size of 25 N). Mean and standard deviations of fatigue loads for the different core thicknesses were 0.5-mm core 610.94 N ±130.11; 0.75-mm core 600.0 N ±132.80; 1.0-mm core 537.50 N ±41.67; a Nd 1.5-mm core 501.14 N ±70.12. All veneered groups were significantly stronger than the full thickness group (ANOVA, Pcore groups (χ(2) test, Pcores increases the fatigue strength of the biceramic system. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  14. High-aspect-ratio photoresist processing for fabrication of high resolution and thick micro-windings

    Science.gov (United States)

    Anthony, Ricky; Laforge, Elias; Casey, Declan P.; Rohan, James F.; O'Mathuna, Cian

    2016-10-01

    DC winding losses remain a major roadblock in realizing high efficiency micro-magnetic components (inductors/transformers). This paper reports an optimized photoresist process using negative tone and acrylic based THB-151N (from JSR Micro), to achieve one of the highest aspect ratio (17:1) and resolution (~5 µm) resist patterns for fabrication of thick (~80 µm) micro-winding using UV lithography. The process was optimized to achieve photoresist widths from 5 µm to 20 µm with resist thickness of ~85 µm in a single spin step. Unlike SU-8, this resist can be readily removed and shows a near-vertical (~91°) electroplated Cu side-wall profile. Moreover, the high resolution compared to available resist processes enables a further reduction in the footprint area and can potentially increase the number of winding thereby increasing the inductance density for micro-magnetic components. Resistance measurements of electroplated copper winding of air-core micro-inductors within the standard 0402 size (0.45 mm2 footprint area) suggested a 42% decrease in resistance (273 mΩ-159 mΩ) with the increase in electroplated Cu thickness (from 50 µm to 80 µm). Reduction of the spacings (from 10 µm to 5 µm) enabled further miniaturisation of the device footprint area (from 0.60 mm2 to 0.45 mm2) without significant increase in resistance.

  15. [The thickness/radius ratio (h/r) of the left ventricle in pure mitral insufficiency].

    Science.gov (United States)

    Guadalajara, J F; Alexánderson, E; Monobe, F; Nieto, S; Huerta, D

    1992-01-01

    We studied 11 patients with severe mitral regurgitation (MR). With 2-D echocardiogram we could obtain the septal and posterior wall thickness, left ventricular internal dimensions and ventricular function. With parasternal short axis view we calculate the h/r ratio (left ventricular thickness/radius). The results were compared with normal values: we found important left atrial and ventricle dilatation with significative difference from the normal values (P < 0.001), the diastolic and systolic h/r ratio was significative lower than the normal values (P < 0.005): the systolic wall stress was significative higher in relation to normal values (P < 0.001). We conclude that patients with severe (MR) initially have an important ventricular dilatation but no hypertrophy despite volume overload. The possible explanation is that in early stages of the disease, the afterload of the left ventricle is low and does not trigger the development of hypertrophy. The hypertrophy appears only when the systolic stress is high secondary to myocardial failure. The excessive dilatation of the left ventricle probably damages the myocardial fibers by excessive stretch. This mechanism probably explains the poor late surgical evolution of patients with mitral prosthesis. This we propose that the optimal surgical timing for such patients is when the systolic wall stress elevates over the normal limits, because this is an early sign of myocardial failure.

  16. Carotid intima media thickness is associated with plasma adiponectin but not with the leptin : adiponectin ratio independently of metabolic syndrome

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; Kappelle, Paul J.W.H.; Dallinga-Thie, Geesje M.

    2010-01-01

    Purpose: A recent report showed no benefit of the leptin: adiponectin ratio (L: A ratio) over individual adipokine levels in CHD prediction [ 8]. We determined associations of carotid intima media thickness (IMT) with the L: A ratio taking account of cardiovascular risk factors in a high risk popula

  17. Carotid intima media thickness is associated with plasma adiponectin but not with the leptin : adiponectin ratio independently of metabolic syndrome

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; Kappelle, Paul J.W.H.; Dallinga-Thie, Geesje M.

    Purpose: A recent report showed no benefit of the leptin: adiponectin ratio (L: A ratio) over individual adipokine levels in CHD prediction [ 8]. We determined associations of carotid intima media thickness (IMT) with the L: A ratio taking account of cardiovascular risk factors in a high risk

  18. Human intraretinal myelination: Axon diameters and axon/myelin thickness ratios

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    Thomas FitzGibbon

    2013-01-01

    Full Text Available Purpose: Human intraretinal myelination of ganglion cell axons occurs in about 1% of the population. We examined myelin thickness and axon diameter in human retinal specimens containing myelinated retinal ganglion cell axons. Materials and Methods: Two eyes containing myelinated patches were prepared for electron microscopy. Two areas were examined in one retina and five in the second retina. Measurements were compared to normal retinal and optic nerve samples and the rabbit retina, which normally contains myelinated axons. Measurements were made using a graphics tablet. Results: Mean axon diameter of myelinated axons at all locations were significantly larger than unmyelinated axons (P ≤ 0.01. Myelinated axons within the patches were significantly larger than axons within the optic nerve (P < 0.01. The relationship between axon diameter/fiber diameter (the G-ratio seen in the retinal sites differed from that in the nerve. G-ratios were higher and myelin thickness was positively correlated to axon diameter (P < 0.01 in the retina but negatively correlated to axon diameter in the nerve (P < 0.001. Conclusion: Intraretinally myelinated axons are larger than non-myelinated axons from the same population and suggests that glial cells can induce diameter changes in retinal axons that are not normally myelinated. This effect is more dramatic on intraretinal axons compared with the normal transition zone as axons enter the optic nerve and these changes are abnormal. Whether intraretinal myelin alters axonal conduction velocity or blocks axonal conduction remains to be clarified and these issues may have different clinical outcomes.

  19. Effect of annealing, thickness ratio and bend angle on springback of AA6061-T6 with non-uniform thickness section

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    Adnan M.F.

    2017-01-01

    Full Text Available Non-uniform thickness section section is considered one of the most effective approaches to reduce automotive part weight. Reduction in term of mass and size result in less fuel consumption and greenhouse gases. Thickness is the most significant parameter to formability, therefore forming a section with non-uniform thickness becomes a great challenge. Improper process and incorrect decision may lead to severe defect and one of the main concerns is the springback. This study will focus on springback behaviour of non-uniform thickness AA6061 strip with complex profile using Taguchi Method. Profile projector (PC 3000 is used to measure the spring back and two-line technique is applied to measure angles (after loading between two lines. Three parameters (i.e. annealing temperature, thickness ratio and bend angle are studied, and results determine that the most significant parameter is bend angle, followed by thickness ratio, and then by the annealing temperature of the specimen during bending process.

  20. Effect of stiffness and thickness ratio of host plate and piezoelectric patches on reduction of the stress concentration factor

    Science.gov (United States)

    Fesharaki, Javad Jafari; Madani, Seyed Ghasem; Golabi, Sa'id

    2016-09-01

    This paper focuses on the effects of stiffness ratio and thickness ratio on reducing stress concentration factor using piezoelectric patches in a rectangular plate with a hole, as a classical shape. Various locations of actuators and induction of positive/negative strains into the host plate are investigated and the best location of patches is presented. The study investigated the ratio effects and piezoelectric patches bounded on a rectangular host plate having various thicknesses and materials. Results show that the best position of actuators varies based on values of thickness and stiffness ratios of the host plate and piezoelectric patches. Also, the location of maximum stress concentration is transmitted from top and bottom of the hole to another point around the edge by changing the location of the piezoelectric actuators. To verify the results, some experimental tests are applied. The results show good agreement between the finite element analysis and experimental tests.

  1. [The effect of core veneer thickness ratio on the flexural strength of diatomite-based dental ceramic].

    Science.gov (United States)

    Jiang, Jie; Zhang, Xin; Gao, Mei-qin; Zhang, Fei-min; Lu, Xiao-li

    2015-06-01

    To evaluate the effect of different core veneer thickness ratios on the flexural strength and failure mode of bilayered diatomite-based dental ceramics. Diatomite-based dental ceramics blocks (16 mm×5.4 mm×1 mm) were sintered with different thickness of veneer porcelains: 0 mm (group A), 0.6 mm (group B), 0.8 mm (group C) and 1.0 mm (group D). Flexural strength was detected and scanning electron microscope was used to observe the interface microstructure. Statistical analysis was performed using SPSS 17.0 software package. With the increase of the thickness of the veneer porcelain, flexural strength of group C showed highest flexural strength up to (277.24±5.47) MPa. Different core veneer thickness ratios can significantly influence the flexural strength of bilayered diatomite-based dental ceramics. Supported by Science and Technology Projects of Nantong City (HS2013010).

  2. Experimental Investigation of a High-Speed Hydrofoil with Parabolic Thickness Distribution and an Aspect Ratio of 3

    Science.gov (United States)

    Christopher, Kenneth W.

    1961-01-01

    An experimental investigation has been made to determine the hydro-dynamic characteristics of a 10-percent-thick hydrofoil with an aspect ratio of 3 designed to operate with acceptable efficiency at speeds in the neighborhood of 100 knots (169 fps). A cambered hydrofoil model with parabolic thickness distribution was investigated at a depth of chord over a range of angles of attack from -0.5 deg to 4.0 deg and at speeds from 120 to 210 fps. substantially wider range of operation at acceptable lift-drag ratios as well as higher maximum lift-drag-ratio values than did a hydrofoil of similar design with an aspect ratio of 1.

  3. Structural, magnetic and microwave properties of barium hexaferrite thick films with different Fe/Ba mole ratio

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Samiksha [School of Physics and Materials Science, Thapar University, Patiala 147004 (India); Dhawan, S.K. [Polymeric & Soft Materials Section, National Physical laboratory, New Delhi 119912 (India); Paesano, Andrea [Departamento de Fisica, Universidade Estadual de Maringá, Av. Colombo 5790, Maringá (Brazil); Pandey, O.P. [School of Physics and Materials Science, Thapar University, Patiala 147004 (India); Sharma, Puneet, E-mail: puneet.sharma@thapar.edu [School of Physics and Materials Science, Thapar University, Patiala 147004 (India)

    2015-12-15

    Barium hexaferrite (BaFe{sub 12}O{sub 19}) thick films (∼60 µm) with different BaO·xFe{sub 2}O{sub 3} mole ratio (x=5.0–6.0) were prepared by screen printing method. X-ray diffraction analysis confirmed the formation of single phase BaFe{sub 12}O{sub 19} (BaM). Preferential site occupation of Fe{sup 3+} ion at five different crystallographic sites, with varied mole ratio was measured by Mössbauer spectroscopy. Vacancy fraction found to be higher at 4f{sub 1}, 4f{sub 2} and 2b sites for mole ratio 5.5 and 5.0 respectively. Magnetic measurement shows that the magnetization (M) and magnetocrystalline anisotropy field (H{sub a}) depends upon mole ratio. M and H{sub a} are found to be maximum for mole ratio 5.5, while the coercivity (H{sub c}) remains constant. Reflection losses (R{sub L}) in the frequency range of 12–18 GHz were also studied. Present investigation demonstrates the effect of mole ratio on structural, magnetic and microwave absorption properties of BaM thick films for microwave device applications. - Highlights: • Single phase BaM thick films with different Fe/Ba mole ratio are prepared. • Site preference of Fe ion is estimated by Mössbauer spectroscopy. • Magnetization and magnetocrystalline ansisotropy is found maximum for 5.5 mole ratio. • Absorption frequency found to vary with the mole ratio.

  4. Study of coercive fields and Kβ/Kα X-ray intensity ratios of nickel films in the thickness range of 5-2000 nm

    Science.gov (United States)

    Prajapat, C. L.; Singh, M. R.; Ravikumar, G.; Gupta, S. K.; Joseph, D.; Nayak, B. K.; Saxena, A.

    2012-06-01

    Coercive fields and X-Ray intensity ratios of the K-series lines of Ni films in the thickness range of 5-2000 nm deposited onto Si (111) substrate have been studied. The Coercive field is observed to increase with thickness and follows power law for the thickness range ≥ 50 nm. For lower thickness, there is a deviation from power law. A correlated change is also observed in the Kβ/Kα X-ray intensity ratios.

  5. Assessment of relation between neutrophil lympocyte, platelet lympocyte ratios and epicardial fat thickness in patients with ankylosing spondylitis.

    Science.gov (United States)

    Boyraz, Ismail; Onur Caglar, Sabri; Erdem, Fatma; Yazici, Mehmet; Yazici, Selma; Koc, Bunyamin; Gunduz, Ramazan; Karakoyun, Ahmet

    2016-02-01

    To investigate whether there is a relation between neutrophillymphocyte (N/L) and platelet- lymphocyte (P/L) ratios and epicardial adipose tissue (EAT) thickness in patients with ankylosing spondylitis (AS). Thirty patients diagnosed with ankylosing spondylitis and 25 healthy people (controls) were included in the study. Age, gender, body mass index (BMI), height, hemogram, sedimentation, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, CRP, hepatic and renal function tests, lipid profile of the all patients were recorded. Data related to duration of the disease, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) values of the cases in the patient group were obtained. A cardiologist measured EAT thickness by ECHO in both patient and control groups. In the patient group, mean BASDAI and BASFI scores were 2.48±2.21 and 1.5±2.07, respectively. Age, gender, BMI values did not show statistically significant difference between the patient and the control groups. N/L and P/L ratios did not change significantly in the patient group having higher EAT, BASFI values and taking anti-TNF compared to the control group. In patients with AS, EAT measurements, which are related to inflammatory response increase, can be used for monitoring of the risk of development of cardiac disease. We could not find the relation between EAT and N/L, P/L ratios in terms of evaluation of inflammatory response. Copyright© by the Medical Assotiation of Zenica-Doboj Canton.

  6. Sagittal abdominal diameter to triceps skinfold thickness ratio: a novel anthropometric index to predict premature coronary atherosclerosis.

    Science.gov (United States)

    Vasheghani-Farahani, Ali; Majidzadeh-A, Keivan; Masoudkabir, Farzad; Karbalai, Shahrokh; Koleini, Maryam; Aiatollahzade-Esfahani, Farah; Pashang, Mina; Hakki, Elham

    2013-04-01

    We aimed to compare the accuracy of a novel index defined by us, as a ratio of Sagittal abdominal diameter (SAD) and triceps skinfold thickness (TSF) with other indices of adiposity for prediction of presence, severity and extension of premature coronary artery disease (CAD). A cross-sectional study was conducted on 238 younger patients (females <55 years; males <45 years) who underwent coronary angiography. Anthropometric indices including TSF, SAD, waist circumference, and hip circumference were measured before catheterization and body mass index, waist-to-hip ratio, abdominal diameter index, index of central obesity as well as our proposed index, SAD-to-TSF ratio, were calculated accordingly. Evaluation of severity and extension of coronary stenosis was by Gensini score and extent score, respectively. After adjustment for age and sex in multivariate regression models, the SAD-to-TSF ratio was the best predictor for the presence (OR = 2.49, 95% CI = 1.44-4.30; p = 0.001) and extension (β = 1.10, p = 0.004) of premature CAD. TSF and the SAD-to-TSF ratio were the only indices that significantly predicted the Gensini score and the correlation remained significant even after adjustment for age and sex (β = -7.28, p < 0.0001 and β = 3.76, p < 0.0001, respectively). We showed that our proposed index, SAD-to-TSF ratio, has a substantially better accuracy than do the known indices of obesity like body mass index, waist circumference, and waist-to-hip ratio for the prediction of premature CAD. Furthermore, our index was the only index that positively correlated with the severity of premature CAD. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Modelling Sediment Thickness for Site-Effect Characterisation using H/V Spectral Ratio Analysis and Electrical Resistivity Tomography

    Science.gov (United States)

    Van Noten, Koen; Lecocq, Thomas; Watlet, Arnaud; Camelbeeck, Thierry

    2014-05-01

    The H/V Spectral Ratio (HVSR) analysis of ambient seismic noise has been widely used to estimate the fundamental site resonance frequency in the context of site-effect characterisation. In regions of unknown subsurface structure, in which there is a significant acoustic impedance contrast between sediments and the underlying bedrock, HVSR can be a very powerful tool to map bedrock morphology and sediment thickness. Calibrating the power-law relationship between the variation in fundamental frequency and sediment thickness around these unknown sites is crucial for sediment thickness mapping. This empirical relationship can be easily calculated by conducting HVSR analysis of ambient noise measurements above boreholes with known bedrock depth. Additional local H/V measurements above near-surface geophysical profiles, for instance created by Electrical Resistivity Tomography (ERT), allow training and improving the power-law relationship for sites with a shallow bedrock depth. As the compaction of sediments influences the Vs, one has however to take into account that this empirical relationship can only be applied in relative small areas with a similar local geology. Between 2008 and 2010, a seismic swarm (MLmax = 3.2) occurred in a hilly area, 20 km SE of Brussels (Belgium). 60 of the 300 recorded events were felt/heard by the local residents and were reported in the corresponding 'Did You Feel It' internet inquiries held by Royal Observatory of Belgium. Several low-magnitude events show a distinct macroseismic intensity variation that can be explained by the geological site effect, i.e. the local sediment thickness, affecting the human perception of these earthquake-induced ground motions. In this presentation, we apply the above described methodology and discuss the results of a geophysical survey including ERT-profiling, ambient noise recording, HVSR analysis in Geopsy and DEM-modelling to characterise the local site effects. The resulting sediment thickness model

  8. An enhanced VIIRS aerosol optical thickness (AOT) retrieval algorithm over land using a global surface reflectance ratio database

    Science.gov (United States)

    Zhang, Hai; Kondragunta, Shobha; Laszlo, Istvan; Liu, Hongqing; Remer, Lorraine A.; Huang, Jingfeng; Superczynski, Stephen; Ciren, Pubu

    2016-09-01

    The Visible/Infrared Imager Radiometer Suite (VIIRS) on board the Suomi National Polar-orbiting Partnership (S-NPP) satellite has been retrieving aerosol optical thickness (AOT), operationally and globally, over ocean and land since shortly after S-NPP launch in 2011. However, the current operational VIIRS AOT retrieval algorithm over land has two limitations in its assumptions for land surfaces: (1) it only retrieves AOT over the dark surfaces and (2) it assumes that the global surface reflectance ratios between VIIRS bands are constants. In this work, we develop a surface reflectance ratio database over land with a spatial resolution 0.1° × 0.1° using 2 years of VIIRS top of atmosphere reflectances. We enhance the current operational VIIRS AOT retrieval algorithm by applying the surface reflectance ratio database in the algorithm. The enhanced algorithm is able to retrieve AOT over both dark and bright surfaces. Over bright surfaces, the VIIRS AOT retrievals from the enhanced algorithm have a correlation of 0.79, mean bias of -0.008, and standard deviation (STD) of error of 0.139 when compared against the ground-based observations at the global AERONET (Aerosol Robotic Network) sites. Over dark surfaces, the VIIRS AOT retrievals using the surface reflectance ratio database improve the root-mean-square error from 0.150 to 0.123. The use of the surface reflectance ratio database also increases the data coverage of more than 20% over dark surfaces. The AOT retrievals over bright surfaces are comparable to MODIS Deep Blue AOT retrievals.

  9. Optimization of laser energy deposition for single-shot high aspect-ratio microstructuring of thick BK7 glass

    Energy Technology Data Exchange (ETDEWEB)

    Garzillo, Valerio; Grigutis, Robertas [Dipartimento di Scienza e Alta Tecnologia, University of Insubria, Via Valleggio 11, I-22100 Como (Italy); Jukna, Vytautas [Centre de Physique Theorique, CNRS, Ecole Polytechnique, Université Paris-Saclay, F-91128 Palaiseau (France); LOA, ENSTA-ParisTech, CNRS, Ecole Polytechnique, Université Paris Saclay, F-91762 Palaiseau (France); Couairon, Arnaud [Centre de Physique Theorique, CNRS, Ecole Polytechnique, Université Paris-Saclay, F-91128 Palaiseau (France); Di Trapani, Paolo [Dipartimento di Scienza e Alta Tecnologia, University of Insubria and CNISM UdR Como, Via Valleggio 11, I-22100 Como (Italy); Jedrkiewicz, Ottavia, E-mail: ottavia.jedrkiewicz@ifn.cnr.it [Istituto di Fotonica e Nanotecnologie, CNR and CNISM UdR Como, Via Valleggio 11, I-22100 Como (Italy)

    2016-07-07

    We investigate the generation of high aspect ratio microstructures across 0.7 mm thick glass by means of single shot Bessel beam laser direct writing. We study the effect on the photoinscription of the cone angle, as well as of the energy and duration of the ultrashort laser pulse. The aim of the study is to optimize the parameters for the writing of a regular microstructure due to index modification along the whole sample thickness. By using a spectrally resolved single pulse transmission diagnostics at the output surface of the glass, we correlate the single shot material modification with observations of the absorption in different portions of the retrieved spectra, and with the absence or presence of spectral modulation. Numerical simulations of the evolution of the Bessel pulse intensity and of the energy deposition inside the sample help us interpret the experimental results that suggest to use picosecond pulses for an efficient and more regular energy deposition. Picosecond pulses take advantage of nonlinear plasma absorption and avoid temporal dynamics effects which can compromise the stationarity of the Bessel beam propagation.

  10. Optimization of laser energy deposition for single-shot high aspect-ratio microstructuring of thick BK7 glass

    Science.gov (United States)

    Garzillo, Valerio; Jukna, Vytautas; Couairon, Arnaud; Grigutis, Robertas; Di Trapani, Paolo; Jedrkiewicz, Ottavia

    2016-07-01

    We investigate the generation of high aspect ratio microstructures across 0.7 mm thick glass by means of single shot Bessel beam laser direct writing. We study the effect on the photoinscription of the cone angle, as well as of the energy and duration of the ultrashort laser pulse. The aim of the study is to optimize the parameters for the writing of a regular microstructure due to index modification along the whole sample thickness. By using a spectrally resolved single pulse transmission diagnostics at the output surface of the glass, we correlate the single shot material modification with observations of the absorption in different portions of the retrieved spectra, and with the absence or presence of spectral modulation. Numerical simulations of the evolution of the Bessel pulse intensity and of the energy deposition inside the sample help us interpret the experimental results that suggest to use picosecond pulses for an efficient and more regular energy deposition. Picosecond pulses take advantage of nonlinear plasma absorption and avoid temporal dynamics effects which can compromise the stationarity of the Bessel beam propagation.

  11. It is unclear if adjusting cortical thickness for changes in gray/white matter intensity ratio improves discrimination between normal aging, MCI, and AD.

    Science.gov (United States)

    Bauer, Corinna M; Cabral, Howard J; Killiany, Ronald J

    2014-03-01

    The contrast between gray and white matter in MRI is critical for accurately measuring cortical thickness. The gray/white matter intensity ratio (GWIR) has been proposed to be an important adjustment factor for cortical thickness measures in Alzheimer's disease (AD) and mild cognitive impairment (MCI). This study examined the GWIR and its influence on cortical thickness in normal aging, mild cognitive impairment (MCI), and AD. The ability for GWIR to discriminate between these groups was assessed on its own and as an adjustment factor for cortical thickness. Minimal age- and AD-related changes in GWIR were observed. GWIR was not able to differentiate between normal aging, MCI, and AD. However, adjusting cortical thickness for GWIR slightly improved the ability to discriminate between groups and the effect size of cortical thickness increased after adjusting for GWIR. This work demonstrates the ambiguity in adjusting cortical thickness measures for GWIR, particularly when attempting to discriminate between normal aging, MCI, and AD groups.

  12. Carotid intima-media thickness and neutrophils/lymphocytes ratio in patients with overt and subclinical hypothyroidism

    Directory of Open Access Journals (Sweden)

    Fahri Güneş

    2013-12-01

    Full Text Available Objective: Hypothyroidism, whether overt or subclinical, has multiple effects on the cardiovascular system. Neutrophil-lymphocyte (N/L rate is closely related to cardiovascular disorders and atherosclerosis. Our study aimed to assess N/L rate and carotid artery intima-media thickness (CIMT in patients with overt and subclinical hypothyroidism (SCH. Methods: The study included 36 patients with SCH and 28 patients with overt hypothyroidism (OH as well as 30 healthy controls. CIMT, thyroid hormone levels, complete blood count and lipid parameters were measured in all subjects. Correlation analysis and linear regression analysis were performed for N/L rate. Results: Mean CIMT was 0.51 ± 0.15, 0.58 ± 0.16, 0.67 ± 0.24 mm in control, SCH, and OH groups, respectively. CIMT of OH patients was high compared with control subjects (P 0.05. It was no correlation that CIMT between N/L ratio (p > 0.05. Conclusion: Neutrophil-lymphocyte rate was not found to be useful indicator of early atherosclerosis in SCH and OH patients. J Clin Exp Invest 2013; 4 (4: 463-446

  13. [Effect of core: dentin thickness ratio on the flexure strength of IPS Empress II heat-pressed all-ceramic restorative material].

    Science.gov (United States)

    Liu, Yi-hong; Feng, Hai-lan; Bao, Yi-wang; Qiu, Yan

    2007-02-18

    To evaluate the effect of core:dentin thickness ratio on the flexure strength, fracture mode and origin of bilayered IPS Empress II ceramic composite specimens. IPS Empress II core ceramic, dentin porcelain and bilayered composite specimens with core:dentin thickness ratio of 2:1 and 1:1 were tested in three-point flexure strength. Mean strengths and standard deviations were determined. The optical microscopy was employed for identification of the fracture mode and origin. The flexure strength of dentin porcelain was the smallest(62.7 MPa), and the strength of bilayered composite specimens was smaller than single-layered core ceramic(190.2 MPa). The core: dentin ratio did not influence the strength of bilayered composite specimens. The frequency of occurrence of bilayered specimen delaminations was higher in the group of core: dentin thickness ratio of 1:1 than in the group of 2:1. IPS Empress II core ceramic was significantly stronger than veneering dentin porcelain. Core:dentin thickness ratio could significantly influence the fracture mode and origin, and bilayered IPS Empress II ceramic composite specimens showed little influence in the fracture strength.

  14. Dependency of Tunneling-Magnetoresistance Ratio on Nanoscale Spacer Thickness and Material for Double MgO Based Perpendicular-Magnetic-Tunneling-Junction.

    Science.gov (United States)

    Lee, Du-Yeong; Hong, Song-Hwa; Lee, Seung-Eun; Park, Jea-Gun

    2016-12-08

    It was found that in double MgO based perpendicular magnetic tunneling junction spin-valves ex-situ annealed at 400 °C, the tunneling magnetoresistance ratio was extremely sensitive to the material and thickness of the nanoscale spacer: it peaked at a specific thickness (0.40~0.53 nm), and the TMR ratio for W spacers (~134%) was higher than that for Ta spacers (~98%). This dependency on the spacer material and thickness was associated with the (100) body-centered-cubic crystallinity of the MgO layers: the strain enhanced diffusion length in the MgO layers of W atoms (~1.40 nm) was much shorter than that of Ta atoms (~2.85 nm) and the shorter diffusion length led to the MgO layers having better (100) body-centered-cubic crystallinity.

  15. Time-dependent fracture probability of bilayer, lithium-disilicate-based, glass-ceramic, molar crowns as a function of core/veneer thickness ratio and load orientation.

    Science.gov (United States)

    Anusavice, Kenneth J; Jadaan, Osama M; Esquivel-Upshaw, Josephine F

    2013-11-01

    Recent reports on bilayer ceramic crown prostheses suggest that fractures of the veneering ceramic represent the most common reason for prosthesis failure. The aims of this study were to test the hypotheses that: (1) an increase in core ceramic/veneer ceramic thickness ratio for a crown thickness of 1.6mm reduces the time-dependent fracture probability (Pf) of bilayer crowns with a lithium-disilicate-based glass-ceramic core, and (2) oblique loading, within the central fossa, increases Pf for 1.6-mm-thick crowns compared with vertical loading. Time-dependent fracture probabilities were calculated for 1.6-mm-thick, veneered lithium-disilicate-based glass-ceramic molar crowns as a function of core/veneer thickness ratio and load orientation in the central fossa area. Time-dependent fracture probability analyses were computed by CARES/Life software and finite element analysis, using dynamic fatigue strength data for monolithic discs of a lithium-disilicate glass-ceramic core (Empress 2), and ceramic veneer (Empress 2 Veneer Ceramic). Predicted fracture probabilities (Pf) for centrally loaded 1.6-mm-thick bilayer crowns over periods of 1, 5, and 10 years are 1.2%, 2.7%, and 3.5%, respectively, for a core/veneer thickness ratio of 1.0 (0.8mm/0.8mm), and 2.5%, 5.1%, and 7.0%, respectively, for a core/veneer thickness ratio of 0.33 (0.4mm/1.2mm). CARES/Life results support the proposed crown design and load orientation hypotheses. The application of dynamic fatigue data, finite element stress analysis, and CARES/Life analysis represent an optimal approach to optimize fixed dental prosthesis designs produced from dental ceramics and to predict time-dependent fracture probabilities of ceramic-based fixed dental prostheses that can minimize the risk for clinical failures. Copyright © 2013 Academy of Dental Materials. All rights reserved.

  16. Impact of P/In flux ratio and epilayer thickness on faceting for nanoscale selective area growth of InP by molecular beam epitaxy.

    Science.gov (United States)

    Fahed, M; Desplanque, L; Coinon, C; Troadec, D; Wallart, X

    2015-07-24

    The impact of the P/In flux ratio and the deposited thickness on the faceting of InP nanostructures selectively grown by molecular beam epitaxy (MBE) is reported. Homoepitaxial growth of InP is performed inside 200 nm wide stripe openings oriented either along a [110] or [1-10] azimuth in a 10 nm thick SiO2 film deposited on an InP(001) substrate. When varying the P/In flux ratio, no major shape differences are observed for [1-10]-oriented apertures. On the other hand, the InP nanostructure cross sections strongly evolve for [110]-oriented apertures for which (111)B facets are more prominent and (001) ones shrink for large P/In flux ratio values. These results show that the growth conditions allow tailoring the nanocrystal shape. They are discussed in the framework of the equilibrium crystal shape model using existing theoretical calculations of the surface energies of different low-index InP surfaces as a function of the phosphorus chemical potential, directly related to the P/In ratio. Experimental observations strongly suggest that the relative (111)A surface energy is probably smaller than the calculated value. We also discuss the evolution of the nanostructure shape with the InP-deposited thickness.

  17. 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.

  18. Horizontal-vertical Spectral Ratio Method in Microtremor to Estimate Engineering Bedrock Thickness at Sedati Mud Volcano

    Science.gov (United States)

    Prabawa Arwananda, Alif; Aryaseta, Bagas; Dezulfakar, Hafidz; Fatahillah, Yosar; Pandu Gya Nur Rochman, Juan

    2017-04-01

    Based on field study, Sedati Mud Volcano located in a line with Gunung Anyar Mud Volcano and occurred by increased pressure in the compression area and rapid loss of gas. The combination of both fast-growing constructions of infrastructures and the presence of the mud volcanoes brings new challenges in Sidoarjo city. The purpose of this scientific research is to determine the sedimentary thickness around Sedati mud volcano. Only a few data show real amplitude spectrum, which represent high contrast impedance. At some point, there are several peaks indicating the presence of contrast impedance between layers. Based on 20 processed data, Sedati Mud Volcano has a 30 - 70m engineering bedrock thickness and natural frequency between 0.5 until 14.4 Hz. The enhancement of natural frequency tends to occur along decrement of layer thickness in the upper basement layer. The result shows the natural frequency parameter and its amplification is slightly variated around Sedati Mud Volcano, as caused by sedimentary lateral depth variation and/or the presence of variation on existing rock. Further analysis indicates a fault inside the area of mud volcano as possible reason behind the occurring mudflow.

  19. The Effect of Blade-Section Thickness Ratio on the Aerodynamic Characteristics of Related Full-Scale Propellers at Mach Numbers up to 0.65

    Science.gov (United States)

    Maynard, Julian D; Steinberg, Seymour

    1953-01-01

    The results of an investigation of two 10-foot-diameter, two-blade NACA propellers are presented for a range of blade angles from 20 degrees to 55 degrees at airspeeds up to 500 miles per hour. These results are compared with those from previous investigations of five related NACA propellers in order to evaluate the effects of blade-section thickness ratios on propeller aerodynamic characteristics.

  20. Evaluation of the horizontal-to-vertical spectral ratio (HVSR) seismic method to determine sediment thickness in the vicinity of the south well field, Franklin county, OH

    Science.gov (United States)

    Haefner, R.J.; Sheets, R.A.; Andrews, R.E.

    2010-01-01

    The horizontal-to-vertical spectral ratio (HVSR) seismic method involves analyzing measurements of ambient seismic noise in three dimensions to determine the fundamental site resonance frequency. Resonance is excited by the interaction of surface waves (Rayleigh and Love) and body waves (vertically incident shear) with the high-contrast acoustic impedance boundary at the bedrock-sediment interface. Measurements were made to determine the method's utility for estimating thickness of unconsolidated glacial sediments at 18 locations at the South Well Field, Franklin County, OH, and at six locations in Pickaway County where sediment thickness was already known. Measurements also were made near a high-capacity production well (with pumping on and off ) and near a highway and a limestone quarry to examine changes in resonance frequencies over a 20-hour period. Although the regression relation for resonance frequency and sediment thickness had a relatively low r 2(0.322), estimates of sediment thickness were, on average, within 14 percent of known thicknesses. Resonance frequencies for pumping on and pumping off were identical, although the amplitude of the peak was nearly double under pumping conditions. Resonance frequency for the 20-hour period did not change, but the amplitude of the peak changed considerably, with a maximum amplitude in the early afternoon and minimum in the very early morning hours. Clay layers within unconsolidated sediments may influence resonance frequency and the resulting regression equation, resulting in underestimation of sediment thickness; however, despite this and other complicating factors, hydrogeologists should consider this method when thickness data are needed for unconsolidated sediments. ?? 2011 by The Ohio Academy of Science. All Rights Reserved.

  1. The Development of High Frequency Welded Pipe with Large Radius-thickness Ratio%大径厚比高频焊管的开发

    Institute of Scientific and Technical Information of China (English)

    李烨; 陈浮; 冷洪刚; 张毅; 孙广东

    2015-01-01

    根据大径厚比圆管的特点 ,选用高效、低成本的高频焊接生产方式 ,采用线性排辊成型工艺 ,并通过对大径厚比高频焊管的铣边、成型、焊接、定径等工艺的研究 ,成功地开发出径厚比≥100的高频焊接圆管 Φ508 × 5 ,该焊管成功地应用于太阳能光伏发电装置.%Based on the characteristics of high frequency welded pipes with large radius-thickness ratio , a highly efficient welding production mode with low cost was applied in this project .Adopting linear cage roll forming process ,and through research of milling ,molding ,welding ,sizing process of making the large diameter-thick ratio of high frequency welded pipe ,the researchers successfully developed the high frequency welded pipe 508 x 5 with a diameter thickness ratio of 100 or more 5 ,the welded tube was suc-cessfully applied to solar energy photovoltaic devices.

  2. Metal location and thickness in a multilayered sheet by measuring Kα/ Kβ, Lα/ Lβ and Lα/ Lγ X-ray ratios

    Science.gov (United States)

    Cesareo, Roberto; Rizzutto, Marcia A.; Brunetti, Antonio; Rao, Donepudi V.

    2009-09-01

    When a multilayered material is analyzed by means of energy-dispersive X-ray fluorescence analysis, then the X-ray ratios of Kα/ Kβ, or Lα/ Lβ and Lα/ Lγ, for an element in the multilayered material, depend on the composition and thickness of the layer in which the element is situated, and on the composition and thickness of the superimposed layer (or layers). Multilayered samples are common in archaeometry, for example, in the case of pigment layers in paintings, or in the case of gilded or silvered alloys. The latter situation is examined in detail in the present paper, with a specific reference to pre-Columbian alloys from various museums in the north of Peru.

  3. Sedimentary and crustal thicknesses and Poisson's ratios for the NE Tibetan Plateau and its adjacent regions based on dense seismic arrays

    Science.gov (United States)

    Wang, Weilai; Wu, Jianping; Fang, Lihua; Lai, Guijuan; Cai, Yan

    2017-03-01

    The sedimentary and crustal thicknesses and Poisson's ratios of the NE Tibetan Plateau and its adjacent regions are estimated by the h- κ stacking and CCP image of receiver functions from the data of 1,317 stations. The horizontal resolution of the obtained results is as high as 0.5° × 0.5°, which can be used for further high resolution model construction in the region. The crustal thicknesses from Airy's equilibrium are smaller than our results in the Sichuan Basin, Qilian tectonic belt, northern Alxa block and Qaidam Basin, which is consistent with the high densities in the mantle lithosphere and may indicate that the high-density lithosphere drags crust down overall. High Poisson's ratios and low velocity zones are found in the mid- and lower crust beneath eastern Qilian tectonic belt and the boundary areas of the Ordos block, indicating that partial melting may exist in these regions. Low Poisson's ratios and low-velocity anomalies are observed in the crust in the NE Tibetan Plateau, implying that the mafic lower crust is thinning or missing and that the mid- and lower crust does not exhibit melting or partial melting in the NE Tibetan Plateau, and weak flow layers are not likely to exist in this region.

  4. [Study of ventricular function by means of echocardiographic quantification of the thickness/radius (h/r) ratio of the left ventricle in healthy subjects].

    Science.gov (United States)

    Guadalajara, J F; Martínez, C; Gutiérrez, E; Zamora, C; Huerta, D

    1989-01-01

    We studied 72 healthy subjects; 31 of them were adults and 41 children. By means of two-dimensional echocardiography we obtained a short axis view at the papillary muscle level of the ratio of the thickness (h) of the ventricular wall and the radius (r) of the cavity. We analysed ventricular performance determinants (pre-load, after-load and contractility). This non-invasive method gives information similar to pressure-volume curves. Thus, we propose it for the study of left ventricular overloads.

  5. Crack initiation modes in bilayered alumina/porcelain disks as a function of core/veneer thickness ratio and supporting substrate stiffness.

    Science.gov (United States)

    Wakabayashi, N; Anusavice, K J

    2000-06-01

    We hypothesize that the fracture resistance of alumina core/porcelain veneer disks increases and that crack initiation shifts from veneer to core as the core/veneer thickness ratio (t(C)/t(V)) increases from 0.5/1.0 to 1.3/0.2, or as the elastic modulus of the supporting substrate (E(S)) to which it is resin-bonded increases from 5.1 to 226 GPa. When supported by a low-modulus substrate, disks with low t(C)/t(V) ratios exhibited cracks in the veneer and within the core, while those with high t(C)/t(V) ratios demonstrated core cracks, but not veneer cracks. None of the disks supported by Ni-Cr alloy (E = 226 GPa) exhibited core cracks. These results support the hypothesis that the crack initiation site shifts as the t(C)/t(V) ratio increases, but the increase in E(S) did not affect the crack initiation site. This study suggests that the t(C)/t(V) ratio is the dominant factor that controls the failure initiation site in bilayered ceramic disks.

  6. Using H/V Spectral Ratio Analysis to Map Sediment Thickness and to Explain Macroseismic Intensity Variation of a Low-Magnitude Seismic Swarm in Central Belgium

    Science.gov (United States)

    Van Noten, K.; Lecocq, T.; Camelbeeck, T.

    2013-12-01

    Between 2008 and 2010, the Royal Observatory of Belgium received numerous ';Did You Feel It'-reports related to a 2-year lasting earthquake swarm at Court-Saint-Etienne, a small town in a hilly area 20 km SE of Brussels, Belgium. These small-magnitude events (-0.7 ≤ ML ≤ 3.2, n = c. 300 events) were recorded both by the permanent seismometer network in Belgium and by a locally installed temporary seismic network deployed in the epicentral area. Relocation of the hypocenters revealed that the seismic swarm can be related to the reactivation of a NW-SE strike-slip fault at 3 to 6 km depth in the basement rocks of the Lower Palaeozoic London-Brabant Massif. This sequence caused a lot of emotion in the region because more than 60 events were felt by the local population. Given the small magnitudes of the seismic swarm, most events were more often heard than felt by the respondents, which is indicative of a local high-frequency earthquake source. At places where the bedrock is at the surface or where it is covered by thin alluvial sediments ( 30 m). In those river valleys that have a considerable alluvial sedimentary cover, macroseismic intensities are again lower. To explain this variation in macroseismic intensity we present a macroseismic analysis of all DYFI-reports related to the 2008-2010 seismic swarm and a pervasive H/V spectral ratio (HVSR) analysis of ambient noise measurements to model the thickness of sediments covering the London-Brabant Massif. The HVSR method is a very powerful tool to map the basement morphology, particularly in regions of unknown subsurface structure. By calculating the soil's fundamental frequency above boreholes, we calibrated the power-law relationship between the fundamental frequency, shear wave velocity and the thickness of sediments. This relationship is useful for places where the sediment thickness is unknown and where the fundamental frequency can be calculated by H/V spectral ratio analysis of ambient noise. In a

  7. Novel markers of endothelial dysfunction and inflammation in Behçet's disease patients with ocular involvement: epicardial fat thickness, carotid intima media thickness, serum ADMA level, and neutrophil-to-lymphocyte ratio.

    Science.gov (United States)

    Yuksel, Murat; Yildiz, Abdulkadir; Oylumlu, Mustafa; Turkcu, Fatih Mehmet; Bilik, Mehmet Zihni; Ekinci, Aysun; Elbey, Bilal; Tekbas, Ebru; Alan, Sait

    2016-03-01

    The etiology of Behçet's disease (BD) has not been fully elucidated. However, immunological and environmental factors, endothelial dysfunction (ED), and genetic susceptibility have been proposed to play a role. In this study, we aimed to evaluate epicardial fat thickness (EFT) together with serum asymmetric dimethylarginine (ADMA), carotid intima media thickness (CIMT), and neutrophil-to-lymphocyte ratio (NLR) in BD patients with ocular involvement. Thirty-six ocular BD patients (17 active and 19 inactive ocular involvement), and 35 age and sex-matched healthy controls were enrolled to this cross-sectional study. All patients underwent examinations with transthoracic echocardiography and carotid Doppler ultrasound. Serum ADMA levels, CIMT, EFT, and NLR were compared between groups, and their association with disease activity was evaluated. Behçet's disease patients had higher WBC counts, neutrophil counts, NLR, CIMT, EFT values, and serum ADMA levels than do healthy controls. The other biochemical, hematological, and echocardiographic parameters were comparable between the two groups. Behçet's disease duration was positively correlated with EFT and CIMT. Multivariate logistic regression analysis revealed that increased serum ADMA concentration and CIMT are independently associated with BD. Neutrophil counts, NLR, and serum ADMA level were higher, and lymphocyte count was lower in patients with active ocular BD compared to those of inactive ocular BD group. Carotid intima media thickness, serum ADMA level, EFT, and NLR were increased in ocular BD patients compared to healthy subjects. In addition, both serum ADMA level and NLR were associated with disease activity of ocular involvement. Increase in disease duration was associated with increase in CIMT and EFT which suggests that anatomical changes occur in time during the disease course. Increased CIMT, serum ADMA level, EFT, and NLR may provide new clues about the role of ED and inflammation in the

  8. Association of serum triglyceride-to-HDL cholesterol ratio with carotid artery intima-media thickness, insulin resistance and nonalcoholic fatty liver disease in children and adolescents.

    Science.gov (United States)

    Pacifico, L; Bonci, E; Andreoli, G; Romaggioli, S; Di Miscio, R; Lombardo, C V; Chiesa, C

    2014-07-01

    The triglyceride (TG)/high-density lipoprotein-cholesterol (HDL-C) ratio has been reported as a useful marker of atherogenic lipid abnormalities, insulin resistance, and cardiovascular disease. We evaluated in a large sample of children and adolescents the association of TG/HDL-C ratio with early signs of morphological vascular changes and cardiometabolic risk factors including nonalcoholic fatty liver disease (NAFLD). The study population, including 548 children (aged 6-16 years), of whom 157 were normal-weight, 118 overweight, and 273 obese, had anthropometric, laboratory, liver and carotid ultrasonography (carotid artery intima-media thickness-cIMT) data collected. Subjects were stratified into tertiles of TG/HDL-C. There was a progressive increase in body mass index (BMI), BMI-SD score (SDS), waist circumference, blood pressure (BP), liver enzymes, glucose, insulin, homeostasis model assessment of insulin resistance, high-sensitivity C-reactive protein (hsCRP), and cIMT values across TG/HDL-C tertiles. The odds ratios for central obesity, insulin resistance, high hsCRP, NAFLD, metabolic syndrome, and elevated cIMT increased significantly with the increasing tertile of TG/HDL-C ratio, after adjustment for age, gender, pubertal status, and BMI-SDS. In a stepwise multivariate logistic regression analysis, increased cIMT was associated with high TG/HDL-C ratio [OR, 1.81 (95% CI, 1.08-3.04); P < 0.05], elevated BP [5.13 (95% CI, 1.03-15.08); P < 0.05], insulin resistance [2.16 (95% CI, 1.30-3.39); P < 0.01], and NAFLD [2.70 (95% CI, 1.62-4.56); P < 0.01]. TG/HDL-C ratio may help identify children and adolescents at high risk for structural vascular changes and metabolic derangement. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Both serum apolipoprotein B and the apolipoprotein B/apolipoprotein A-I ratio are associated with carotid intima-media thickness.

    Directory of Open Access Journals (Sweden)

    Fei Huang

    Full Text Available BACKGROUND: Previous studies indicated that apolipoprotein measurements predicted cardiovascular disease (CVD risk; however, associations between apolipoproteins and carotid intima-media thickness (CIMT were less explored. METHODOLOGY AND PRINCIPAL FINDINGS: The cross-sectional study included 6069 participants aged 40 years or older with NGT from Shanghai, China. Serum fasting traditional lipids (total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C] and triglycerides [TG], apoA-I and apoB were assessed. A high-resolution B-mode ultrasonography was performed to measure CIMT. We found CIMT increased progressively across the quartiles of serum apoB (p for trend <0.0001. In logistic regression, concentrations of apoB (odds ratio [OR] 1.27, 95% confidence interval [CI] 1.18-1.36, TC (OR 1.23, 95% CI 1.14-1.32, LDL-C (OR 1.25, 95% CI 1.16-1.34 and TG (OR 1.11, 95% CI 1.04-1.20 were significantly related to elevated CIMT after adjusted for age and sex. Meanwhile, the apoB/apoA-I ratio (OR 1.25, 95% CI 1.17-1.34 related to elevated CIMT. ApoB (OR 1.23, 95% CI 1.00-1.51 and the apoB/apoA-I ratio (OR 1.19, 95% CI 1.04-1.36 remained significantly associated with elevated CIMT, after adjusted for the traditional CVD risk factors including traditional lipids. CONCLUSIONS AND SIGNIFICANCE: There were significant associations between serum apoB, the apoB/apoA-I ratio and elevated CIMT. Serum apoB and the apoB/apoA-I ratio might be independent predictors of early atherosclerosis in NGT.

  10. Research on sub-surface damage and its stress deformation in the process of large aperture and high diameter-to-thickness ratio TMT M3MP

    Science.gov (United States)

    Hu, Hai-xiang; Qi, Erhui; Cole, Glen; Hu, Hai-fei; Luo, Xiao; Zhang, Xue-jun

    2016-10-01

    Large flat mirrors play important roles in large aperture telescopes. However, they also introduce unpredictable problems. The surface errors created during manufacturing, testing, and supporting are all combined during measurement, thus making understanding difficult for diagnosis and treatment. Examining a high diameter-to-thickness ratio flat mirror, TMT M3MP, and its unexpected deformation during processing, we proposed a strain model of subsurface damage to explain the observed phenomenon. We designed a set of experiment, and checked the validity of our diagnosis. On that basis, we theoretical predicted the trend of this strain and its scale effect on Zerodur®, and checked the validity on another piece experimentally. This work guided the grinding-polishing process of M3MP, and will be used as reference for M3M processing as well.

  11. Triglyceride to high-density lipoprotein cholesterol ratio and carotid intima-medial thickness in Chinese adolescents with newly diagnosed type 2 diabetes mellitus.

    Science.gov (United States)

    Li, Xin; Deng, You-Ping; Yang, Miao; Wu, Yu-Wen; Sun, Su-Xin; Sun, Jia-Zhong

    2016-03-01

    To investigate the relationship between triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio and carotid intima-medial thickness (CIMT) in Chinese youth and adolescents with newly diagnosed type 2 diabetes mellitus (T2DM). Ninety-eight subjects aged 10-24 yr with newly-diagnosed T2DM had general inflammation, anthropometric, laboratory and CIMT data collected, and were divided into three groups based on TG/HDL-C tertiles. There were no significant differences in gender, age, fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), and carotid arterial diameter (CAD) among the groups based on TG/HDL-C tertiles. Across TG/HDL-C tertiles, there was a significant progressive increase in body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), homeostasis model assessment-estimated insulin resistance (HOMA-IR), TG, total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and CIMT (all P < 0.01 or P < 0.05), while HDL-C was decreased significantly across the groups (P < 0.01). In general linear regression model, TG/HDL-C was an independent determinant of CIMT even after adjusting for BMI, SBP, DBP, TG, TC, LDL-C, HDL-C, HbA1c and HOMA-IR. TG/HDL-C ratio, the marker of small dense LDL particles, is an independent determinant of CIMT in Chinese youth and adolescents with newly diagnosed T2DM, and may be a simple and helpful tool in predicting the increased CIMT in such patients. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Q460高强钢管径厚比限值试验研究%Experimental Study on Diameter-Thickness Ratio Limitation of Q460 High-Strength Steel Tubes

    Institute of Scientific and Technical Information of China (English)

    邢海军; 高渊; 朱彬荣

    2012-01-01

    If the diameter-thickness ratio of steel lubes exceeds a certain limit, local buckling will occur before overall buckling in steel components under pressure, which makes the steel components loose the whole-area weight bearing capability and accelerates the overall instability process. The application of sled tubes with large diameter-thickness ratio in transmission lines is mainly limited by the diameter-thickness ratio. By comparison between domestic and international standards, compression tests on 18 sets of steel axial components and theoretical analysis, the internal relationships between the diameter-thickness ratio, the slendemess ratio and the weight bearing capacity are analyzed in detail. The limitation of diameter-thickness ratio for Q460 steel lubes is put forward, which could provide guidance fur the current design of transmission line steel lowers.%当钢管的径厚比超过一定限值时,钢管构件受压时局部屈曲先于整体稳定破坏,使构件不能全面积承载,从而会加速构件整体失稳而丧失承载能力.输电线路中对于大径厚比钢管使用的限制主要以径厚比限值来实现.通过国内外规范对比、18组钢管构件轴心受压试验和理论分析相结合的方法,研究分析了Q460钢管径厚比及其长细比与钢管承载力的内在关系,并得到Q460钢管径厚比限值,该限值的试验验证对目前输电线路钢管塔设计具有指导意义.

  13. Highly Enhanced TMR Ratio and Δ for Double MgO-based p-MTJ Spin-Valves with Top Co2Fe6B2 Free Layer by Nanoscale-thick Iron Diffusion-barrier.

    Science.gov (United States)

    Lee, Seung-Eun; Baek, Jong-Ung; Park, Jea-Gun

    2017-09-19

    For double MgO-based p-MTJ spin-valves with a top Co2Fe6B2 free layer ex-situ annealed at 400 °C, the insertion of a nanoscale-thickness Fe diffusion barrier between the tungsten (W) capping layer and MgO capping layer improved the face-centered-cubic (f.c.c.) crystallinity of both the MgO capping layer and tunneling barrier by dramatically reducing diffusion of W atoms from the W capping layer into the MgO capping layer and tunneling barrier, thereby enhancing the TMR ratio and thermal stability (Δ). In particular, the TMR ratio was extremely sensitive to the thickness of the Fe barrier; it peaked (154%) at about 0.3 nm (the thickness of only two atomic Fe layers). The effect of the diffusion barrier originated from interface strain.

  14. Thermal stability dependence on the stacking order and thickness ratio of the CoPt -TiO2/CoCrPt-SiO2 stacked media

    Science.gov (United States)

    Park, S. H.; Lee, T. D.; Kong, S. H.; Yoon, S. Y.; Lee, H. S.; Kim, H. J.; Oh, H. S.

    2008-04-01

    Thermal stability of the present CoCrPt -SiO2 media becomes a more critical issue as recording density steadily increases. In the present study, thermal stability of the stacked media composed of high Ku CoPt -TiO2 and normal Ku CoCrPt -SiO2 was studied by changing stacking order and thickness of each layer while keeping a constant total thickness. When the CoPt -TiO2 layer was placed under the CoCrPt -SiO2 layer, negative nucleation field and coercivity increased much more than those of the reverse stacking case. Thermal stability of the CoPt -TiO2 bottom group was superior to that of the CoCrPt -SiO2 bottom group when measured by a spin stand.

  15. The ratio of change in muscle thickness between superficial and deep cervical flexor muscles during the craniocervical flexion test and a suggestion regarding clinical treatment of patients with musculoskeletal neck pain.

    Science.gov (United States)

    Goo, Miran; Kim, Seong-Gil; Jun, Deokhoon

    2015-08-01

    [Purpose] The purpose of this study was to identify the imbalance of muscle recruitment in cervical flexor muscles during the craniocervical flexion test by using ultrasonography and to propose the optimal level of pressure in clinical craniocervical flexion exercise for people with neck pain. [Subjects and Methods] A total of 18 students (9 males and 9 females) with neck pain at D University in Gyeongsangbuk-do, South Korea, participated in this study. The change in muscle thickness in superficial and deep cervical flexor muscles during the craniocervical flexion test was measured using ultrasonography. The ratio of muscle thickness changes between superficial and deep muscles during the test were obtained to interpret the imbalance of muscle recruitment in cervical flexor muscles. [Results] The muscle thickness ratio of the sternocleidomastoid muscle/deep cervical flexor muscles according to the incremental pressure showed significant differences between 22 mmHg and 24 mmHg, between 24 mmHg and 28 mmHg, between 24 mmHg and 30 mmHg, and between 26 mmHg and 28 mmHg. [Conclusion] Ultrasonography can be applied for examination of cervical flexor muscles in clinical environment, and practical suggestion for intervention exercise of craniocervical flexors can be expected on the pressure level between 24 mmHg and 26 mmHg enabling the smallest activation of the sternocleidomastoid muscle.

  16. Effects of caving-mining ratio on the coal and waste rocks gangue flows and the amount of cyclically caved coal in fully mechanized mining of super-thick coal seams

    Institute of Scientific and Technical Information of China (English)

    Zhang Ningbo; Liu Changyou; Pei Mengsong

    2015-01-01

    Aimed at determining the appropriate caving–mining ratio for fully mechanized mining of 20 m thick coal seam, this research investigated the effects of caving–mining ratio on the flow fields of coal and waste rocks, amount of cyclically caved coal and top coal loss by means of numerical modeling. The research was based on the geological conditions of panel 8102 in Tashan coal mine. The results indicated the loose coal and waste rocks formed an elliptical zone around the drawpoint. The ellipse enlarged with decreasing caving–mining ratio. And its long axis inclined to the gob gradually became vertical and facil-itating the caving and recovery of top coal. The top coal loss showed a cyclical variation;and the loss cycle was shortened with the decreasing in caving–mining ratio. Moreover, the mean squared error (MSE) of the amount of cyclically caved coal went up with increasing caving–mining ratio, indicating a growing imbalance of amount of cyclically caved coal, which could impede the coordinated mining and caving operations. Finally it was found that a caving–mining ratio of 1:2.51 should be reasonable for the conditions.

  17. Metal location and thickness in a multilayered sheet by measuring K{alpha}/K{beta}, L{alpha}/L{beta} and L{alpha}/L{gamma} X-ray ratios

    Energy Technology Data Exchange (ETDEWEB)

    Cesareo, Roberto [Dip. di Matematica e Fisica, Universita di Sassari, via Vienna 2, 07100 Sassari (Italy)], E-mail: cesareo@uniss.it; Rizzutto, Marcia A. [Instituto de Fisica, Universidade de Sao Paulo, CEP 0558-090, Sao Paulo (Brazil)], E-mail: rizzutto@dfn.if.usp.br; Brunetti, Antonio [Dip. di Matematica e Fisica, Universita di Sassari, via Vienna 2, 07100 Sassari (Italy)], E-mail: brunetti@uniss.it; Rao, Donepudi V. [Dip. di Matematica e Fisica, Universita di Sassari, via Vienna 2, 07100 Sassari (Italy); Dept. of Physics, SIR CRR Autonomous College, Eluru, AP (India)], E-mail: donepudi_venkateswararao@rediffmail.com

    2009-09-01

    When a multilayered material is analyzed by means of energy-dispersive X-ray fluorescence analysis, then the X-ray ratios of K{alpha}/K{beta}, or L{alpha}/L{beta} and L{alpha}/L{gamma}, for an element in the multilayered material, depend on the composition and thickness of the layer in which the element is situated, and on the composition and thickness of the superimposed layer (or layers). Multilayered samples are common in archaeometry, for example, in the case of pigment layers in paintings, or in the case of gilded or silvered alloys. The latter situation is examined in detail in the present paper, with a specific reference to pre-Columbian alloys from various museums in the north of Peru.

  18. Comparison of Limiting Width-Thickness Ratios of Steel Columns in Sino-foreign Seismic Design Codes%中外抗震设计规范关于钢柱板件宽厚比限值的比较

    Institute of Scientific and Technical Information of China (English)

    邓椿森; 施刚; 张勇; 王元清; 石永久

    2011-01-01

    板件宽厚比对钢结构的抗震性能有着重要影响,同时也是影响钢结构用钢量的一项重要指标,对钢结构的安全性和经济性均有着很重要的意义.目前国内已有不少文献认为我国现行抗震设计规范对梁柱截面板件宽厚比限值的规定尚不够严谨和完善,并对此提出了设计建议.结合中国抗震规范GB50011—2001、美国钢结构抗震规范ANSI/AISC 341—05、日本抗震规范BCJ和欧洲抗震规范Eurocode 8的相关规定,比较研究了中外抗震设计规范对工形截面和箱形截面钢柱板件宽厚比限值规定的异同,分析了中国抗震规范GB50011—2001关于钢柱板件宽厚比限值的合理性,为相关设计和研究提供了参考.%The limiting width-thickness ratio plays an important role in steel structures' safety and economy,as it not only has a significant influence on steel structures' seismic performance,but also is an important index of steel consumption for steel structures.At present,many domestic research results show that the limiting width-thickness ratios in our country's seismic design code are not adequate or reasonable and have presented corresponding design recommendation.The limiting width-thickness ratios in the related Chinese code GB50011—2001,American code ANSI/AISC 341—05,Japanese code BCJ and European code Eurocode 8 are compared and analyzed,which provides a reference for the relevant steel structure design and research.

  19. Wind-tunnel investigation of longitudinal and lateral-directional stability and control characteristics of a 0.237-scale model of a remotely piloted research vehicle with a thick, high-aspect-ratio supercritical wing

    Science.gov (United States)

    Byrdsong, T. A.; Brooks, C. W., Jr.

    1980-01-01

    A 0.237-scale model of a remotely piloted research vehicle equipped with a thick, high-aspect-ratio supercritical wing was tested in the Langley 8-foot transonic tunnel to provide experimental data for a prediction of the static stability and control characteristics of the research vehicle as well as to provide an estimate of vehicle flight characteristics for a computer simulation program used in the planning and execution of specific flight-research mission. Data were obtained at a Reynolds number of 16.5 x 10 to the 6th power per meter for Mach numbers up to 0.92. The results indicate regions of longitudinal instability; however, an adequate margin of longitudinal stability exists at a selected cruise condition. Satisfactory effectiveness of pitch, roll, and yaw control was also demonstrated.

  20. Influence of the Shell Thickness and Ratio Between Core Elements on Photostability of the CdTe/CdS Core/Shell Quantum Dots Embedded in a Polymer Matrix.

    Science.gov (United States)

    Doskaliuk, Nataliia; Khalavka, Yuriy; Fochuk, Petro

    2016-12-01

    This paper reports a study of photooxidation and photomodification processes of the CdTe/CdS quantum dots embedded in a polymer matrix under ambient condition. During the first few minutes of irradiation, the quasi-inverse increase in photoluminescence intensity has been observed indicating the passivation of the nanocrystal surface traps by water molecules. A prolonged irradiation of the polymer film containing CdTe/CdS quantum dots leads to a significant decrease in the photoluminescence intensity together with the "blue shift" of the photoluminescence peak energy associated with quantum dot photooxidation. The mechanisms of the CdTe/CdS core/shell quantum dot photooxidation and photomodification in a polymer matrix are discussed. We have found a correlation between the photostability of the quantum dots and the CdS shell thickness as well as the ratio of core elements.

  1. Effects of core-to-dentin thickness ratio on the biaxial flexural strength, reliability, and fracture mode of bilayered materials of zirconia core (Y-TZP) and veneer indirect composite resins.

    Science.gov (United States)

    Su, Naichuan; Liao, Yunmao; Zhang, Hai; Yue, Li; Lu, Xiaowen; Shen, Jiefei; Wang, Hang

    2017-01-01

    Indirect composite resins (ICR) are promising alternatives as veneering materials for zirconia frameworks. The effects of core-to-dentin thickness ratio (C/Dtr) on the mechanical property of bilayered veneer ICR/yttria-tetragonal zirconia polycrystalline (Y-TZP) core disks have not been previously studied. The purpose of this in vitro study was to assess the effects of C/Dtr on the biaxial flexural strength, reliability, and fracture mode of bilayered veneer ICR/ Y-TZP core disks. A total of 180 bilayered 0.6-mm-thick composite resin disks in core material and C/Dtr of 2:1, 1:1, and 1:2 were tested with either core material placed up or placed down for piston-on-3-ball biaxial flexural strength. The mean biaxial flexural strength, Weibull modulus, and fracture mode were measured to evaluate the variation trend of the biaxial flexural strength, reliability, and fracture mode of the bilayered disks with various C/Dtr. One-way analysis of variance (ANOVA) and chi-square tests were used to evaluate the variation tendency of fracture mode with the C/Dtr or material placed down during testing (α=.05). Light microscopy was used to identify the fracture mode. The mean biaxial flexural strength and reliability improved with the increase in C/Dtr when specimens were tested with the core material either up and down, and depended on the materials that were placed down during testing. The rates of delamination, Hertzian cone cracks, subcritical radial cracks, and number of fracture fragments partially depended on the C/Dtr and the materials that were placed down during testing. The biaxial flexural strength, reliability, and fracture mode in bilayered structures of Y-TZP core and veneer ICR depend on both the C/Dtr and the material that was placed down during testing. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  2. 步宽/骨盆宽度比值和步长/骨盆厚度比值在脑瘫患儿步行康复中的作用研究%Study on the effect of the ratio of step width/pelvis width ratio and length/thickness ratio on walking rehabilitation of children with cerebral palsy

    Institute of Scientific and Technical Information of China (English)

    林国良

    2016-01-01

    目的:探讨步宽/骨盆宽度比值和步长/骨盆厚度比值在脑瘫患儿步行康复中的定量分析价值。方法选择2013年9月~2015年7月收治的脑瘫患儿50例作为研究对象,随机将其分为治疗组和对照组,各25例。均进行测量步宽/骨盆宽度和步长/骨盆厚度,治疗组以测量数据为基础,采用以跪位姿势结合踝足控制训练为主的综合康复治疗,对照组采用常规康复。步行功能评估采用粗大运动功能量表(gross motor function measure,GMFM)的E区评定,平衡能力评估采用Berg平衡功能量表(Berg balance scale,BBS)评定。结果步宽/骨盆宽度与GMFM E区评分呈高度负相关,差异有统计学意义(P<0.05);在控制步宽/骨盆宽度的影响后,步长/骨盆厚度与GMFM E区评分呈高度正相关,差异有统计学意义(P<0.05)。治疗组GMFM E区评分显著高于治疗前,差异有统计学意义(P<0.05),且显著优于对照组,差异有统计学意义(P<0.05)。结论步宽/骨盆宽度和步长/骨盆厚度在脑瘫患儿步行康复训练体系中具有良好的应用价值,值得推广。%Objective To investigate the step width/thickness of pelvis and step length/width pelvic in children with cerebral palsy rehabilitation in the quantitative analysis of the value on foot.Methods Selection of 50 cases of children with cerebral palsy were 2013.9 2015.7,were randomly divided into treatment group and control group, both for step width/thickness of the pelvis and step length/width pelvic measurement, quantitative analysis of the pelvis , adopt to kneel a pose with ankle foot control training comprehensive rehabilitation treatment method. Walking function evaluation using GMFM E zone evaluation, balance capability assessment using function of BBS. Results All children into the result analysis.Showed that the step width/pelvis width and GMFM E score is highly negative correlation(P<0.05);In

  3. Optimum thickness of Mossbauer absorber

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    If recoilless fraction fa is available, the optimum absorber thickness dopt can be calculated by maximizing the signal to noise ratio or Q factor. In this work,an approach presented is to get experimental Qexp as a function of the thickness, and then fitting Qexp by its theoretical expression gives fa value. At last the dopt value is deduced from a maximum on the fitted curve. In such a way, thicknesses of six specimens with quadrupole or magnetic hyperfine splitting were optimized.

  4. High Plasma Glucagon Levels Correlate with Waist-to-Hip Ratio, Suprailiac Skinfold Thickness, and Deep Subcutaneous Abdominal and Intraperitoneal Adipose Tissue Depots in Nonobese Asian Indian Males with Type 2 Diabetes in North India.

    Science.gov (United States)

    Anoop, Shajith; Misra, Anoop; Bhatt, Surya Prakash; Gulati, Seema; Mahajan, Harsh; Prabakaran, Gokulraj

    2017-01-01

    We aimed to correlate plasma glucagon levels with anthropometric measures and abdominal adipose tissue depots. Nonobese males (n = 81; BMI skinfolds), whole-body DEXA (for body fat and fat-free mass), and MRI scan (for volumes of subcutaneous abdominal adipose tissue (SCAT) including superficial and deep, intra-abdominal visceral adipose tissue (including intraperitoneal adipose tissue (IPAT), retroperitoneal adipose tissue, liver span and fatty liver, and pancreatic volume)). Plasma glucose and glucagon, serum insulin, hepatic transaminases, and lipid profile were measured. Significantly higher levels of fasting and postprandial glucagon (p skinfold thickness, IPAT, and deep SCAT (p < 0.05; r(2) = 0.84). These observations in Asian Indians may have significance for diabetes therapies which impact glucagon levels.

  5. Dependency of tunneling magnetoresistance ratio on Pt seed-layer thickness for double MgO perpendicular magnetic tunneling junction spin-valves with a top Co2Fe6B2 free layer ex-situ annealed at 400 °C

    Science.gov (United States)

    Takemura, Yasutaka; Lee, Du-Yeong; Lee, Seung-Eun; Park, Jea-Gun

    2016-12-01

    For the double MgO based perpendicular magnetic tunneling junction (p-MTJ) spin-valves with a top Co2Fe6B2 free layer ex situ annealed at 400 °C, the tunneling-magnetoresistance ratio (TMR) strongly depended on the platinum (Pt) seed layer thickness (t Pt): it peaked (˜134%) at a specific t Pt (3.3 nm). The TMR ratio was initially and slightly increased from 113%-134% by the enhancement of the magnetic moment of the Co2Fe6B2 pinned layer when t Pt increased from 2.0-3.3 nm, and then rapidly decreased from 134%-38.6% by the degrading face-centered-cubic crystallinity of the MgO tunneling barrier when t Pt increased from 3.3-14.3 nm.

  6. The thickness of glaciers

    Science.gov (United States)

    Faraoni, Valerio; Vokey, Marshall W.

    2015-09-01

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

  7. Education and "Thick" Epistemology

    Science.gov (United States)

    Kotzee, Ben

    2011-01-01

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

  8. Thick film hydrogen sensor

    Science.gov (United States)

    Hoffheins, Barbara S.; Lauf, Robert J.

    1995-01-01

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  9. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  10. Origami of thick panels

    Science.gov (United States)

    Chen, Yan; Peng, Rui; You, Zhong

    2015-07-01

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

  11. Small-scale models of multiring basins

    Science.gov (United States)

    Allemand, Pascal; Thomas, Pierre

    1999-07-01

    Small-scale sand-silicone simulations of multiring impact structures have been undertaken in order to understand the effects of the rheology of the lithosphere on the variability of natural multiring structures. For low sand-silicone thickness ratio (1:3), brittle strain is accommodated by spiral strike-slip faults. For higher sand-silicone ratios (1:1 or 2:1), an inner concentric ring affected by strike-slip faults is relayed by an external ring affected by concentric normal faults. The diameter of the inner ring decreases with the increase of the sand-silicone thickness ratio. It is suggested that the flexure of the brittle layer due to the silicone flow is responsible for the brittle strain field which is enhanced by the channel flow of the lower crust. The characteristic geometry of the intersection of conjugated strike-slip faults can be observed around large multiring basins on silicate crust such as Orientale on the Moon and on icy crust, such as Valhalla on Callisto and Gilgamesh on Ganymede. The strain field around these large craters is discussed in terms of mechanical properties of the lithospheres. On the Moon, large craters without relaxation faults, such as Imbrium are located on thin crust regions. The crust was too thin to have a ductile lower layer at the time of impact. Gilgamesh on Ganymede is surrounded mainly by strike-slip faults. Asgard on Callisto has the same diameter as Gilgamesh but is surrounded by concentric normal faults. The brittle-ductile thickness ratio is thus higher on Callisto than on Ganymede.

  12. Through-thickness inhomogeneity of localized corrosion in 7050-T7451 Al alloy thick plate

    Institute of Scientific and Technical Information of China (English)

    丰雷; 潘清林; 韦莉莉; 黄志其; 刘志铭

    2015-01-01

    The through-thickness corrosion inhomogeneity of 7050-T7451 Al alloy thick plate was studied using immersion tests, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), slow strain rate testing (SSRT) technique combined with optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the through-thickness corrosion resistance is ranked in the order of T/2>surface>T/4. And the 75 mm-thick 7050 alloy plate presents better corrosion resistance than the 35 mm-thick plate. The results are discussed in terms of the combined effect of recrystallization and cooling rate in quenching. Alloy with lower volume fraction of recrystallization and smaller grain aspect ratio displays better corrosion resistance. The lower corrosion resistance caused by the slower cooling rate results from the higher coverage rate of grain boundary precipitates and larger width of precipitate free zone.

  13. Mechanical Properties of Additively Manufactured Thick Honeycombs

    Directory of Open Access Journals (Sweden)

    Reza Hedayati

    2016-07-01

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

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

    Science.gov (United States)

    Henderson, Brenda; Kinzie, Kevin; Haskin, Henry

    2004-01-01

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

  15. How thick is the lithosphere?

    Science.gov (United States)

    Kanamori, H; Press, F

    1970-04-25

    A rapid decrease in shear velocity in the suboceanic mantle is used to infer the thickness of the lithosphere. It is proposed that new and highly precise group velocity data constrain the solutions and imply a thickness near 70 km.

  16. Free vibration analysis of Mindlin plates with linearly varying thickness

    Science.gov (United States)

    Aksu, G.; Al-Kaabi, S. A.

    1987-12-01

    A method based on the variational principles in conjunction with the finite difference technique is applied to examine the free vibration characteristics of isotropic rectangular plates of linearly varying thickness by including the effects of transverse shear deformation and rotary inertia. The validity of the present approach is demonstrated by comparing the results with other solutions proposed for plates with uniform and linearly varying thickness. Natural frequencies and mode shapes of Mindlin plates with simply supported and clamped edges are determined for various values of relative thickness ratio and the taper thickness constant.

  17. Thick-Big Descriptions

    DEFF Research Database (Denmark)

    Lai, Signe Sophus

    The paper discusses the rewards and challenges of employing commercial audience measurements data – gathered by media industries for profitmaking purposes – in ethnographic research on the Internet in everyday life. It questions claims to the objectivity of big data (Anderson 2008), the assumption...... communication systems, language and behavior appear as texts, outputs, and discourses (data to be ‘found’) – big data then documents things that in earlier research required interviews and observations (data to be ‘made’) (Jensen 2014). However, web-measurement enterprises build audiences according...... to a commercial logic (boyd & Crawford 2011) and is as such directed by motives that call for specific types of sellable user data and specific segmentation strategies. In combining big data and ‘thick descriptions’ (Geertz 1973) scholars need to question how ethnographic fieldwork might map the ‘data not seen...

  18. Disentangling The Thick Concept Argument

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2007-01-01

    Critics argue that non-cognitivism cannot adequately account for the existence and nature of some thick moral concepts. They use the existence of thick concepts as a lever in an argument against non-cognitivism, here called the Thick Concept Argument (TCA). While TCA is frequently invoked...

  19. Disentangling The Thick Concept Argument

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2007-01-01

    Critics argue that non-cognitivism cannot adequately account for the existence and nature of some thick moral concepts. They use the existence of thick concepts as a lever in an argument against non-cognitivism, here called the Thick Concept Argument (TCA). While TCA is frequently invoked...

  20. Grado de acuerdo entre los índices adiposo-musculares obtenidos a partir de medidas antropométricas del brazo, pliegues cutáneos e impedancia bioeléctrica Interchangeability of the fat-to-fat-free mass ratios obtained by arm anthropometric measures, skinfold thickness and bioelectrical impedance

    Directory of Open Access Journals (Sweden)

    V. Martín Moreno

    2003-04-01

    agreement among the fat-to-fat-free mass ratios obtained by arm anthropometric measures (fat-muscle index, FMI, Siri equation for the sum of four skinfold thickness (body fat-muscle index, BFMI Siri and triceps skinfold (BFMItriceps and bioelectrical impedance (BFMI Omron methods. Methods: This is a cross-sectional study. A total of 145 patients were evaluated by anthropometry and bioelectrical impedance (Omron BF 300(, being estimated the agreement through the Intraclass Correlation Coefficient (ICC and Bland-Altman method. The reference method was BFMI Siri. Results: The ICC between BFMI Siri - BFMItriceps were 0,9304 (0,9035; 0,9498, between BFMI Siri - FMI of 0,7726 (0,6846; 0,8361 and between BFMI Siri - BFMI Omron of 0,9114 (0,8771; 0,9361. BFMItriceps (limits of agreement -0,171 to 0,117 show the best agreement according to Bland-Altman analysis with BFMI Siri, followed by BMFI Siri - BFMI Omron (-0,186; 0,178. The agreement limits between FMI and BFMI Siri (-0,2; 0,42, BFMItriceps (-0,26; 0,42 or BFMI Omron (-0,292; 0,504 were beyond of the established cut-off points (-0,2; 0,2. Conclusions: Due to the nature of the statistical agreement BFMItriceps and BFMI Omron are methods interchangeable methods between them and with BFMI Siri. FMI is not interchangeable with BFMI Siri, BFMI Omron or BFMItriceps. These results suggest that FMI cannot estimate properly the body composition. BFMItriceps and BFMI Omron are valid alternative methods to be used instead BFMI Siri in the fat-to-fat-free mass ratio assessment.

  1. ON THE FORMATION OF GALACTIC THICK DISKS

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-01

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

  2. Effects of Neutron Skin Thickness in Peripheral Nuclear Reactions

    Institute of Scientific and Technical Information of China (English)

    FANG De-Qing; MA Yu-Gang; CAI Xiang-Zhou; TIAN Wen-Dong; WANG Hong-Wei

    2011-01-01

    Effects of neutron skin thickness in peripheral nuclear collisions are investigated using the statistical abrasion ablation (SAA) model. The reaction cross section, neutron (proton) removal cross section, one-neutron (proton) removal cross section as well as their ratios for nuclei with different neutron skin thickness are studied. It is demonstrated that there are good linear correlations between these observables and the neutron skin thickness for neutron-rich nuclei. The ratio between the (one-)neutron and proton removal cross section is found to be the most sensitive observable of neutron skin thickness. Analysis shows that the relative increase of this ratio could be used to determine the neutron skin size in neutron-rich nuclei.%Effects of neutron skin thickness in peripheral nuclear collisions are investigated using the statistical abrasion ablation (SAA ) model.The reaction cross section,neutron (proton) removal cross section,one-neutron (proton) removal cross section as well as their ratios for nuclei with different neutron skin thickness are studied.It is demonstrated that there are good linear correlations between these observables and the neutron skin thickness for neutron-rich nuclei.The ratio between the (one-)neutron and proton removal cross section is found to be the most sensitive observable of neutron skin thickness.Analysis shows that the relative increase of this ratio could be used to determine the neutron skin size in neutron-rich nuclei.Determining the size and shape of a nucleus is one of the most important subjects since the discovery of atomic nuclei.The rms radii of the neutron (rn) and proton (rp) density distributions are among the most prominent observables for this purpose.Studies for stable nuclei have shown that the nuclear radii are proportional to A1/3,with A being the nuclear mass number.Meanwhile,the density distributions of neutrons and protons in stable nuclei are very similar.

  3. Finite element analysis on stresses field of normalized layer thickness within ceramic coating on aluminized steel

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Multilayer ceramic coatings were fabricated on steel substrate using a combined technique of hot dipping aluminum(HDA)and plasma electrolytic oxidation(PEO). A triangle of normalized layer thickness was created for describing thickness ratios of HDA/PEO coatings. Then, the effect of thickness ratio on stresses field of HDA/PEO coatings subjected to uniform normal contact load was investigated by finite element method. Results show that the surface tensile stress is mainly affected by the thickness ratio of Al layer when the total thickness of coating is unchanged. With the increase of Al layer thickness, the surface tensile stress rises quickly. When Al2O3 layer thickness increases, surface tensile stress is diminished. Meanwhile, the maximum shear stress moves rapidly towards internal part of HDA/PEO coatings. Shear stress at the Al2O3/Al interface is minimal when Al2O3 layer and Al layer have the same thickness.

  4. Interfacial contribution to thickness dependent in-plane anisotropic magnetoresistance

    Directory of Open Access Journals (Sweden)

    M. Tokaç

    2015-12-01

    Full Text Available We have studied in-plane anisotropic magnetoresistance (AMR in cobalt films with overlayers having designed electrically interface transparency. With an electrically opaque cobalt/overlayer interface, the AMR ratio is shown to vary in inverse proportion to the cobalt film thickness; an indication that in-plane AMR is a consequence of anisotropic scattering with both volume and interfacial contributions. The interface scattering anisotropy opposes the volume scattering contribution, causing the AMR ratio to diminish as the cobalt film thickness is reduced. An intrinsic interface effect explains the significantly reduced AMR ratio in ultra-thin films.

  5. Static and dynamic through thickness lamina properties of thick laminates

    NARCIS (Netherlands)

    Lahuerta, F.; Nijssen, R.P.L.; Van der Meer, F.P.; Sluys, L.J.

    2015-01-01

    Thick laminates are increasingly present in large composites structures such as wind turbine blades. Different factors are suspected to be involved in the decreased static and dynamic performance of thick laminates. These include the effect of self-heating, the scaling effect, and the manufacturing

  6. A new probe of neutron skin thickness

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-Yan; ZHOU Pei; FANG De-Qing; MA Yu-Gang; CAI Xiang-Zhou; CHEN Jin-Gen; GUO Wei; TIAN Wen-Dong; WANG Hong-Wei; ZHANG Guo-Qiang

    2011-01-01

    The correlation between neutron-to-proton yield ratio (R) and neutron skin thickness (δ) in neutron-rich projectile induced reactions is investigated within the framework of the Isospin-Dependent Quantum Molecular Dynamics (IQMD) model. The density distribution of the Droplet model is embedded in the initialization of the neutron and proton densities in the present IQMD model. By adjusting the diffuseness parameter of neutron density in the Droplet model for the projectile, the relationship between the neutron skin thickness and the corresponding R is obtained. The results show strong linear correlation between R and δ for neutron-rich Ca and Ni isotopes. It is suggested that R may be used as an experimental observable to extract δ for neutron-rich nuclei, which is very interesting in the study of the nuclear structure of exotic nuclei, the equation of state (EOS) of asymmetric nuclear matter and neutron-rich matter in astrophysics, etc.

  7. Hybrid Optimization for Wind Turbine Thick Airfoils

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-15

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

  8. Validation of Cooper's ligament thickness in software breast phantoms

    Science.gov (United States)

    Kuperavage, Adam J.; Imran, Abdullah-Al-Zubaer; Bakic, Predrag R.; Maidment, Andrew; Pokrajac, David D.

    2017-03-01

    Anthropomorphic breast phantoms are important tools for a wide range of tasks including pre-clinical validation of novel imaging techniques. In order to improve the realism in the phantoms, assessment of simulated anatomical structures is crucial. Thickness of simulated Cooper's ligaments influences the percentage of dense tissue, as well as qualitative and quantitative properties of simulated images. We introduce three methods (2-dimensional watershed, 3-dimensional watershed, and facet counting) to assess the thickness of the simulated Cooper's ligaments in the breast phantoms. For the validation of simulated phantoms, the thickness of ligaments has been measured and compared with the input thickness values. These included a total of 64 phantoms with nominal ligament thicknesses of 200, 400, 600, and 800 μm. The 2-dimensional and 3-dimensional watershed transformations were performed to obtain the median skeleton of the ligaments. In the 2-dimensional watershed, the median skeleton was found cross-section by cross-section, while the skeleton was found for the entire 3-dimensional space in the 3-dimensional watershed. The thickness was calculated by taking the ratio of the total volume of ligaments and the volume of median skeleton. In the facet counting method, the ligament thickness was estimated as a ratio between estimated ligaments' volume and average ligaments' surface area. We demonstrated that the 2-dimensional watershed technique overestimates the ligament thickness. Good agreement was found between the facet counting technique and the 3-dimensional watershed for assessing thickness. The proposed techniques are applicable for ligaments' thickness estimation on clinical breast images, provided segmentation of Cooper's ligaments has been performed.

  9. Huge thick conglomerate movement induced by full thick longwall mining huge thick coal seam

    Institute of Scientific and Technical Information of China (English)

    Ma Liqiang; Qiu Xiaoxiang; Dong Tao; Zhang Jixiong; Huang Yanli

    2012-01-01

    A discrete elemental method was used to study the thickness of conglomerate layer in a full thick seam mining activities under the influence of the law,pointing out the thickness of the conglomerate at different seam mining,and during the destruction and instability of existing state of laws.At 21141 thick seam mining,the face toward the direction of separation between the thick layer of conglomerate rock and the next bit after reaching its maximum capacity due to pull from the bottom of the plastic zone,formed a stratified and hierarchical down collapse.The shape of caving area is a "triangular block",the length of the plastic zone and face advancement from the linear fit between the height of the plastic zone and the advancing face is a quadratic function of distance,while the top layer of thick gravel layer is the overall bending subsidence trend.Tilting the direction of the face,a thick gob of collapsed conglomerate layer is formed in the coal gob entity on both sides of the thick conglomerate at the top of the overall fracture morphology performance,thus forming a mutual extrusion of articulated block structure.The instability,separation and balance of the thick conglomerate layer in the hinged block stope stress leads to abnormal occurrence of rock burst induced by face as the major factor in the accident.This research reveals the form of stress distribution in the destroyed layer of the thick conglomerate rock,analyzes the stope law of coupling for the pressure burst behavior law for the mining work face,and the choice of preventive measures to provide a theoretical basis and implementation.

  10. 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.

  11. Origami-Inspired Folding of Thick, Rigid Panels

    Science.gov (United States)

    Trease, Brian P.; Thomson, Mark W.; Sigel, Deborah A.; Walkemeyer, Phillip E.; Zirbel, Shannon; Howell, Larry; Lang, Robert

    2014-01-01

    To achieve power of 250 kW or greater, a large compression ratio of stowed-to-deployed area is needed. Origami folding patterns were used to inspire the folding of a solar array to achieve synchronous deployment; however, origami models are generally created for near-zero-thickness material. Panel thickness is one of the main challenges of origami-inspired design. Three origami-inspired folding techniques (flasher, square twist, and map fold) were created with rigid panels and hinges. Hinge components are added to the model to enable folding of thick, rigid materials. Origami models are created assuming zero (or near zero) thickness. When a material with finite thickness is used, the panels are required to bend around an increasingly thick fold as they move away from the center of the model. The two approaches for dealing with material thickness are to use membrane hinges to connect the panels, or to add panel hinges, or hinges of the same thickness, at an appropriate width to enable folding.

  12. Peripapillary choroidal thickness in childhood.

    Science.gov (United States)

    Read, Scott A; Alonso-Caneiro, David; Vincent, Stephen J; Collins, Michael J

    2015-06-01

    Changes in the thickness of the invivo peripapillary choroid have been documented in a range of ocular conditions in adults; however, choroidal thickness in the peripapillary region of children has not been examined in detail. This study therefore aimed to investigate the thickness of the peripapillary choroid and the overlying retinal nerve fibre layer (RNFL) in a population of normal children with a range of refractive errors. Ninety-three children (37 myopes and 56 non-myopes) aged between 11 and 16 years, had measurements of peripapillary choroidal and RNFL thickness derived from enhanced depth imaging optical coherence tomography images (EDI-OCT, Heidelberg Spectralis). The average thickness was determined in a series of five 0.25 mm width concentric annuli (each divided into 8 equal sized 45° sectors) centred on the optic nerve head boundary, accounting for individual ocular magnification factors and the disc-fovea angle. Significant variations in peripapillary choroidal thickness were found to occur with both annulus location (p choroid (mean 77 ± 16 μm) and the outermost annulus, the thickest choroid (191 ± 52 μm). The choroid was thinnest inferior to the optic nerve head (139 ± 38 μm) and was thickest in the superior temporal sector (157 ± 40 μm). Significant differences in the distribution of choroidal thickness were also associated with myopia, with myopic children having significantly thinner choroids in the inner and outer annuli of the nasal and temporal sectors respectively (p thickness also varied significantly with annulus location and sector (p thickness distribution associated with refractive error. This study establishes the normal variations in the thickness of the peripapillary choroid with radial distance and azimuthal angle from the optic nerve head boundary. A significant thinning of the peripapillary choroid associated with myopia in childhood was also observed in both nasal and temporal regions. The changes in peripapillary RNFL

  13. 不同组分厚度比的LaMnO3/SrTiO3异质界面电子结构和磁性的第一性原理研究∗%First-principles study of the electronic prop erties and magnetism of LaMnO3/SrTiO3 heterointerface with the different comp onent thickness ratios

    Institute of Scientific and Technical Information of China (English)

    颜送灵; 唐黎明; 赵宇清

    2016-01-01

    基于密度泛函理论的第一性原理计算,研究了(LaMnO3)n/(SrTiO3)m(LMO/STO)异质界面的离子弛豫、电子结构和磁性质。研究表明,不同组分厚度比及界面类型时,离子弛豫程度各不相同,并且界面处的电子性质受此影响较大。对于n型界面,当LMO的厚度达到6个单胞层后,电子会从LMO转移到STO,转移的电子占据界面层Ti原子的3d电子轨道,界面处出现二维电子气。对于n型界面(LMO)n/(STO)2,随着LMO厚度数n的增加,由离子弛豫造成的结构畸变减小,而界面处Ti原子周围电子的态密度和自旋极化却增大,表明高厚度比的n型界面有利于产生高迁移率的二维电子气和自旋极化。而对于p型(LMO)2/(STO)8界面,在STO一侧基本没有结构畸变,界面处无电子转移和自旋极化现象。通过计算平均静电势发现n型和p型界面处的势差大小相差2 eV,解释了p型界面不容易发生电荷转移的原因。%Using first-principles calculations based on density functional theory and projector augmented wave method, we investigate the thickness ratio dependences of the ionic relaxation, electronic structure, and magnetism of (LaMnO3)n/(SrTiO3)m heterostructure. Polar and nonpolar oxide interfaces have become a hot point of research in con-densed matter physics;in this system, polar discontinuity at the interface may cause charge transfer to occur at interfaces between Mott and band insulating perovskites. Here, we consider two types of interfaces, namely n-type (LaO)+/(TiO2)0 and p-type (MnO2)−/(SrO)0 interfaces. The results show that the different thickness ratios and interface-types lead to different degrees of ionic relaxation, inducing charges of different concentrations to transfer. The distortions of the oxygen octahedra are found to vary distinctly with the component thickness ratio (n : m), which is consistent with recent experimental results. Furthermore, both n and m are found to strongly affect the charge

  14. Continuous image distortion by astrophysical thick lenses

    CERN Document Server

    Kling, Thomas P

    2011-01-01

    Image distortion due to weak gravitational lensing is examined using a non-perturbative method of integrating the geodesic deviation and optical scalar equations along the null geodesics connecting the observer to a distant source. The method we develop continuously changes the shape of the pencil of rays from the source to the observer with no reference to lens planes in astrophysically relevant scenarios. We compare the projected area and the ratio of semi-major to semi-minor axes of the observed elliptical image shape for circular sources from the continuous, thick-lens method with the commonly assumed thin-lens approximation. We find that for truncated singular isothermal sphere and NFW models of realistic galaxy clusters, the commonly used thin-lens approximation is accurate to better than 1 part in 10^4 in predicting the image area and axes ratios. For asymmetric thick lenses consisting of two massive clusters separated along the line of sight in redshift up to \\Delta z = 0.2, we find that modeling the ...

  15. Star Counts and Nature of the Galactic Thick Disk

    Science.gov (United States)

    Yoshii, Yuzuru

    Modern star counts at high Galactic latitudes played a major role in revealing the existence of a thick disk as the third stellar component of the Milky Way Galaxy in addition to the old thin disk and halo. A number of star count observations and models showed that the thick disk is represented well by a double exponential density law in the vertical and radial directions. The thick-disk structural parameters determined to date from star count analysis are reviewed, and their limitations are described in terms of the correlation among the derived parameters. The recent preference for h Z ˜ 0. 7 kpc for the scale height of the thick disk, associated with f thick ˜ 0. 1 for its normalization relative to the thin disk, is likely a consequence of the recent popularity of the flattened inner halo with an axial ratio of q ˜ 0. 6 prescribed in star-count modeling. This value of h Z for the thick disk is supported by the kinematic constraint of ˜ 40 km s- 1 for the measured vertical velocity dispersion of candidate thick-disk stars more than 1 kpc from the disk plane. Furthermore, star counts in multiple directions and from all-sky near-infrared surveys have arrived at a convergent result, indicating that the thick disk has a scale length h R ˜ 3. 5 kpc and has a greater radial extension compared to the thin disk, with h R ˜ 2. 5 kpc. Other constraints have arisen from high-resolution spectroscopic observations of the kinematics, chemical abundances, and ages of candidate thick-disk stars, confirming the rotational lag of ˜ 40 km s- 1 as well as the vertical gradients of the mean rotation and velocity dispersions in three directions, the constant ratio of alpha to the iron abundances [α/Fe] of ˜ +0.4 dex up to [Fe/H] ˜ - 0.4 dex, a large scatter of metallicity around the mean [Fe/H] ˜ - 0.8 dex with little or no spatial gradient, and a fairly old thick-disk age of ˜ 10 Gyr. The star counts and other constraints together indicate dissipational contraction and

  16. 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.

  17. 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.

  18. 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.

  19. Pumping slots and thickness of the LHC beam screen

    CERN Document Server

    Mostacci, A

    1999-01-01

    RF losses through the pumping slots in the LCH beam screen scale exponentially with the ratio of screen thickness to slot width. We present numeric results in graphic form and a simplified analytic fit that can be useful to further optimise the beam screen design. This note is based on a minor revision of CERN LHC Project Report 199

  20. Electrophoretic deposition and constrained sintering of strontium titanate thick films

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Luís; Vilarinho, Paula M., E-mail: paula.vilarinho@ua.pt; Senos, Ana M.R.

    2015-01-15

    Thick films of functional oxides are currently substituting counterparts bulk ceramics, as in the case of low loss dielectrics. For SrTiO{sub 3} (ST) based compositions it is demonstrated that electrophoretic deposition (EPD), using acetone as a suspension media with iodine addition, is a suitable technology to fabricate 12 μm thick films. The microstructural analysis of the films sintered at 1500 °C shows that highly densified microstructures can be obtained and, by slightly varying the Sr/Ti stoichiometry in the powder composition, increased densification and grain size and enlargement of the distribution with decreasing Sr/Ti ratio can be observed. In spite of the high densification of the films, it is also demonstrated that due to the constraint imposed by the substrate a smaller grain size is observed in thick films as compared to equivalent bulk ceramics. In addition, a preferential vertical pore orientation is observed in ST thick films. These results may have broad implications if one considers that the dielectric losses and dielectric tunability is affected by pore orientation, since it affects the electric field distribution. - Highlights: • Nonstoichiometry effect on microstructure of constrained sintered thick films and bulk is similar. • Increased densification and grain size and enlargement of distribution with decreasing Sr/Ti ratio. • Independent of Sr/Ti ratio smaller grain size for thick films compared to ceramics. • Preferential vertical pore orientation for constrained sintering of thick films. • Anisotropic porosity as tailoring factor to engineer permittivity and tunability.

  1. Financial Key Ratios

    Directory of Open Access Journals (Sweden)

    Tănase Alin-Eliodor

    2014-08-01

    Full Text Available This article focuses on computing techniques starting from trial balance data regarding financial key ratios. There are presented activity, liquidity, solvency and profitability financial key ratios. It is presented a computing methodology in three steps based on a trial balance.

  2. Offer/Acceptance Ratio.

    Science.gov (United States)

    Collins, Mimi

    1997-01-01

    Explores how human resource professionals, with above average offer/acceptance ratios, streamline their recruitment efforts. Profiles company strategies with internships, internal promotion, cooperative education programs, and how to get candidates to accept offers. Also discusses how to use the offer/acceptance ratio as a measure of program…

  3. Compression Ratio Adjuster

    Science.gov (United States)

    Akkerman, J. W.

    1982-01-01

    New mechanism alters compression ratio of internal-combustion engine according to load so that engine operates at top fuel efficiency. Ordinary gasoline, diesel and gas engines with their fixed compression ratios are inefficient at partial load and at low-speed full load. Mechanism ensures engines operate as efficiently under these conditions as they do at highload and high speed.

  4. Specialized ratio analysis.

    Science.gov (United States)

    Wyer, J C; Salzinger, F H

    1983-01-01

    Many common management techniques have little use in managing a medical group practice. Ratio analysis, however, can easily be adapted to the group practice setting. Acting as broad-gauge indicators, financial ratios provide an early warning of potential problems and can be very useful in planning for future operations. The author has gathered a collection of financial ratios which were developed by participants at an education seminar presented for the Virginia Medical Group Management Association. Classified according to the human element, system component, and financial factor, the ratios provide a good sampling of measurements relevant to medical group practices and can serve as an example for custom-tailoring a ratio analysis system for your medical group.

  5. Eddy current thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, Gary J.; Sinclair, Frank; Soskov, Alexander; Buff, James S.

    2015-06-16

    A sheet of a material is disposed in a melt of the material. The sheet is formed using a cooling plate in one instance. An exciting coil and sensing coil are positioned downstream of the cooling plate. The exciting coil and sensing coil use eddy currents to determine a thickness of the solid sheet on top of the melt.

  6. Fabrication of high-aspect ratio SU-8 micropillar arrays

    DEFF Research Database (Denmark)

    Amato, Letizia; Keller, Stephan S.; Heiskanen, Arto

    2012-01-01

    SU-8 is the preferred photoresist for development and fabrication of high aspect ratio (HAR) three dimensional patterns. However, processing of SU-8 is a challenging task, especially when the film thickness as well as the aspect ratio is increasing and the size of the features is close to the res...

  7. 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.

  8. Applicability of spectral indices on thickness identification of oil slick

    Science.gov (United States)

    Niu, Yanfei; Shen, Yonglin; Chen, Qihao; Liu, Xiuguo

    2016-10-01

    Hyperspectral remote sensing technology has played a vital role in the identification and monitoring of oil spill events, and amount of spectral indices have been developed. In this paper, the applicability of six frequently-used indices is analyzed, and a combination of spectral indices in aids of support vector machine (SVM) algorithm is used to identify the oil slicks and corresponding thickness. The six spectral indices are spectral rotation (SR), spectral absorption depth (HI), band ratio of blue and green (BG), band ratio of BG and shortwave infrared index (BGN), 555nm and 645nm normalized by the blue band index (NB) and spectral slope (ND). The experimental study is conducted in the Gulf of Mexico oil spill zone, with Airborne Visible Infrared Imaging Spectrometer (AVIRIS) hyperspectral imagery captured in May 17, 2010. The results show that SR index is the best in all six indices, which can effectively distinguish the thickness of the oil slick and identify it from seawater; HI index and ND index can obviously distinguish oil slick thickness; BG, BGN and NB are more suitable to identify oil slick from seawater. With the comparison among different kernel functions of SVM, the classify accuracy show that the polynomial and RBF kernel functions have the best effect on the separation of oil slick thickness and the relatively pure seawater. The applicability of spectral indices of oil slick and the method of oil film thickness identification will in aids of oil/gas exploration and oil spill monitoring.

  9. Difference and ratio plots

    DEFF Research Database (Denmark)

    Svendsen, Anders Jørgen; Holmskov, U; Bro, Peter

    1995-01-01

    hitherto unnoted differences between controls and patients with either rheumatoid arthritis or systemic lupus erythematosus. For this we use simple, but unconventional, graphic representations of the data, based on difference plots and ratio plots. Differences between patients with Burkitt's lymphoma...... and systemic lupus erythematosus from another previously published study (Macanovic, M. and Lachmann, P.J. (1979) Clin. Exp. Immunol. 38, 274) are also represented using ratio plots. Our observations indicate that analysis by regression analysis may often be misleading....

  10. Effects of thickness on electronic structure of titanium thin films

    Indian Academy of Sciences (India)

    Güvenç Akgül

    2014-02-01

    Effects of thickness on the electronic structure of e-beam evaporated thin titanium films were studied using near-edge X-ray absorption fine structure (NEXAFS) technique at titanium 2,3 edge in total electron yield (TEY) mode and transmission yield mode. Thickness dependence of 2,3 branching ratio (BR) of titanium was investigated and it was found that BR below 3.5 nm shows a strong dependence on film thickness. Mean electron escape depth () in titanium, an important parameter for surface applications, was determined to be = 2.6 ± 0.1 nm using 2,3 resonance intensity variation as a function of film thickness. The average 3/2 white line intensity ratio of titanium was obtained as 0.89 from the ratio of amplitudes of each 3 and 2 peaks and 0.66 from the integrated area under each 3 and 2 peaks. In addition, a theoretical calculation for pure titanium was presented for comparison with experimental data.

  11. Accurate thickness measurement of graphene

    Science.gov (United States)

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

    2016-03-01

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

  12. Minimum thickness anterior porcelain restorations.

    Science.gov (United States)

    Radz, Gary M

    2011-04-01

    Porcelain laminate veneers (PLVs) provide the dentist and the patient with an opportunity to enhance the patient's smile in a minimally to virtually noninvasive manner. Today's PLV demonstrates excellent clinical performance and as materials and techniques have evolved, the PLV has become one of the most predictable, most esthetic, and least invasive modalities of treatment. This article explores the latest porcelain materials and their use in minimum thickness restoration.

  13. Accurate thickness measurement of graphene.

    Science.gov (United States)

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

    2016-03-29

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

  14. Soliton models for thick branes

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-15

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

  15. Layer thickness evaluation for transuranic transmutation in a fusion–fission system

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez, Carlos E., E-mail: carlosvelcab@eng-nucl.mest.ufmg.br [Departamento de Engenharia Nuclear—Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627 Campus UFMG, 31.270-90, Belo Horizonte, MG (Brazil); Instituto Nacional de Ciência e Tecnologia de Reatores Nucleares Inovadores/CNPq, Rio de Janeiro, RJ (Brazil); Rede Nacional de Fusão (FINEP/CNPq), Rio de Janeiro, RJ (Brazil); Pereira, Claubia, E-mail: claubia@nuclear.ufmg.br [Departamento de Engenharia Nuclear—Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627 Campus UFMG, 31.270-90, Belo Horizonte, MG (Brazil); Instituto Nacional de Ciência e Tecnologia de Reatores Nucleares Inovadores/CNPq, Rio de Janeiro, RJ (Brazil); Rede Nacional de Fusão (FINEP/CNPq), Rio de Janeiro, RJ (Brazil); Veloso, Maria Auxiliadora F., E-mail: dora@nuclear.ufmg.br [Departamento de Engenharia Nuclear—Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627 Campus UFMG, 31.270-90, Belo Horizonte, MG (Brazil); Instituto Nacional de Ciência e Tecnologia de Reatores Nucleares Inovadores/CNPq, Rio de Janeiro, RJ (Brazil); Rede Nacional de Fusão (FINEP/CNPq), Rio de Janeiro, RJ (Brazil); Costa, Antonella L., E-mail: antonella@nuclear.ufmg.br [Departamento de Engenharia Nuclear—Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627 Campus UFMG, 31.270-90, Belo Horizonte, MG (Brazil); Instituto Nacional de Ciência e Tecnologia de Reatores Nucleares Inovadores/CNPq, Rio de Janeiro, RJ (Brazil); Rede Nacional de Fusão (FINEP/CNPq), Rio de Janeiro, RJ (Brazil)

    2015-05-15

    Highlights: • Layer thickness for transmutation in a fusion–fission system was evaluated. • The calculations were performed using MONTEBURNS code. • The results indicate the best thickness and volume ratio to induce transmutation. - Abstract: Layer thickness for transuranic transmutation in a fusion–fission system was evaluated using two different ways. In the first one, transmutation layer thicknesses were designed maintaining the fuel rod radius constant; in the second part, while the transmutation layer thickness increases, the fuel rod radius decreases maintaining k{sub s} (source-multiplication factor) ≈0.95. Spent fuel reprocessed by UREX+ method and then spiked with thorium and uranium composes the transmutation layer. The calculations were performed using MONTEBURNS code (MCNP5 and ORIGEN 2.1). The results indicate the best thickness and the volume ratio between the coolant and the fuel composition to induce transmutation.

  16. Ratios of Normal Variables

    Directory of Open Access Journals (Sweden)

    George Marsaglia

    2006-05-01

    Full Text Available This article extends and amplifies on results from a paper of over forty years ago. It provides software for evaluating the density and distribution functions of the ratio z/w for any two jointly normal variates z,w, and provides details on methods for transforming a general ratio z/w into a standard form, (a+x/(b+y , with x and y independent standard normal and a, b non-negative constants. It discusses handling general ratios when, in theory, none of the moments exist yet practical considerations suggest there should be approximations whose adequacy can be verified by means of the included software. These approximations show that many of the ratios of normal variates encountered in practice can themselves be taken as normally distributed. A practical rule is developed: If a < 2.256 and 4 < b then the ratio (a+x/(b+y is itself approximately normally distributed with mean μ = a/(1.01b − .2713 and variance 2 = (a2 + 1/(b2 + .108b − 3.795 − μ2.

  17. Ratios of Normal Variables

    Directory of Open Access Journals (Sweden)

    George Marsaglia

    2006-05-01

    Full Text Available This article extends and amplifies on results from a paper of over forty years ago. It provides software for evaluating the density and distribution functions of the ratio z/w for any two jointly normal variates z,w, and provides details on methods for transforming a general ratio z/w into a standard form, (a+x/(b+y , with x and y independent standard normal and a, b non-negative constants. It discusses handling general ratios when, in theory, none of the moments exist yet practical considerations suggest there should be approximations whose adequacy can be verified by means of the included software. These approximations show that many of the ratios of normal variates encountered in practice can themselves be taken as normally distributed. A practical rule is developed: If a < 2.256 and 4 < b then the ratio (a+x/(b+y is itself approximately normally distributed with mean μ = a/(1.01b - .2713 and variance σ2 = (a2 + 1/(b2 + .108b - 3.795 μ2.

  18. Potential support ratios

    DEFF Research Database (Denmark)

    Kjærgaard, Søren; Canudas-Romo, Vladimir

    2017-01-01

    , the prospective potential support ratio usually focuses on the current mortality schedule, or period life expectancy. Instead, in this paper we look at the actual mortality experienced by cohorts in a population, using cohort life tables. We analyse differences between the two perspectives using mortality models......, historical data, and forecasted data. Cohort life expectancy takes future mortality improvements into account, unlike period life expectancy, leading to a higher prospective potential support ratio. Our results indicate that using cohort instead of period life expectancy returns around 0.5 extra younger...

  19. Mastectomy Flap Thickness and Complications in Nipple-Sparing Mastectomy: Objective Evaluation using Magnetic Resonance Imaging.

    Science.gov (United States)

    Frey, Jordan D; Salibian, Ara A; Choi, Mihye; Karp, Nolan S

    2017-08-01

    Ischemic complications after nipple-sparing mastectomy (NSM) have been associated with numerous variables. However, the impact of NSM flap thickness has been incompletely evaluated. NSM flap thickness was determined for all NSMs from 2006 to 2016 with available pre- or postoperative breast magnetic resonance imaging (MRIs). Demographics and outcomes were stratified by those with and without ischemic complications. Of 1,037 NSM reconstructions, 420 NSMs had MRI data available, which included 379 preoperative MRIs and 60 postoperative MRIs. Average total preoperative skin/subcutaneous tissue NSM flap thickness was 11.4 mm. Average total postoperative NSM flap thickness was 8.7 mm. NSMs with ischemic complications were found to have significantly thinner overall postoperative NSM flap thickness compared with those without ischemic complications (P = 0.0280). Average overall postoperative NSM flap thickness less than 8.0 mm was found to be an independent predictor of ischemic complications (odds ratio, 6.5263; P = 0.026). In NSMs with both pre- and postoperative MRIs, the overall average postoperative NSM flap thickness was 68.2% of preoperative measurements. Average overall postoperative NSM flap thickness was significantly less than average overall preoperative NSM flap thickness (P < 0.0001). NSMs with ischemic complications were found to have a significantly lower ratio of overall postoperative to preoperative flap thickness (52.0% versus 74.0%; P < 0.0001). Ischemic complications after NSM are significantly associated with thinner postoperative NSM flap thickness. Particularly, NSM flap thickness less than 8.0 mm is a positive independent predictor of ischemic complications. The ratio of postoperative to preoperative NSM flap thickness was significantly lower in reconstructions with ischemic complications.

  20. Simulations of minor mergers - II. The phase-space structure of thick discs

    NARCIS (Netherlands)

    Villalobos, Alvaro; Helmi, Amina

    2009-01-01

    We analyse the phase-space structure of simulated thick discs that are the result of a 5:1 mass-ratio merger between a disc galaxy and a satellite. Our main goal is to establish what would be the imprints of a merger origin for the Galactic thick disc. We find that the spatial distribution predicted

  1. Gender Ratio in Dyslexia.

    Science.gov (United States)

    Miles, T. R.; Haslum, M. N.; Wheeler, T. J.

    1998-01-01

    A study involving 11,804 British children (age 10) found that when specified criteria for dyslexia were used, 269 children qualified as dyslexic. These included 223 boys and 46 girls, for a ratio of 4.51 to 1. Difficulties in interpreting these data are discussed and a defense of the criteria is provided. (Author/CR)

  2. The rectilinear Steiner ratio

    Directory of Open Access Journals (Sweden)

    PO de Wet

    2005-06-01

    Full Text Available The rectilinear Steiner ratio was shown to be 3/2 by Hwang [Hwang FK, 1976, On Steiner minimal trees with rectilinear distance, SIAM Journal on Applied Mathematics, 30, pp. 104– 114.]. We use continuity and introduce restricted point sets to obtain an alternative, short and self-contained proof of this result.

  3. Accommodating Thickness in Origami-Based Deployable Arrays

    Science.gov (United States)

    Zirbel, Shannon A.; Magleby, Spencer P.; Howell, Larry L.; Lang, Robert J.; Thomson, Mark W.; Sigel, Deborah A.; Walkemeyer, Phillip E.; Trease, Brian P.

    2013-01-01

    The purpose of this work is to create deployment systems with a large ratio of stowed-to-deployed diameter. Deployment from a compact form to a final flat state can be achieved through origami-inspired folding of panels. There are many models capable of this motion when folded in a material with negligible thickness; however, when the application requires the folding of thick, rigid panels, attention must be paid to the effect of material thickness not only on the final folded state, but also during the folding motion (i.e., the panels must not be required to flex to attain the final folded form). The objective is to develop new methods for deployment from a compact folded form to a large circular array (or other final form). This paper describes a mathematical model for modifying the pattern to accommodate material thickness in the context of the design, modeling, and testing of a deployable system inspired by an origami six-sided flasher model. The model is demonstrated in hardware as a 1/20th scale prototype of a deployable solar array for space applications. The resulting prototype has a ratio of stowed-to-deployed diameter of 9.2 (or 1.25 m deployed outer diameter to 0.136 m stowed outer diameter).

  4. Increased brain cortical thickness associated with visceral fat in adolescents.

    Science.gov (United States)

    Saute, R L; Soder, R B; Alves Filho, J O; Baldisserotto, M; Franco, A R

    2016-10-27

    There has been a growing amount of evidence indicating that excess visceral fat is associated with alterations in brain structure and function, including brain cortical thinning in adults. This study aims to investigate the relationship between brain cortical thickness with obesity assessments, in adolescents. In this study, we measured three different obesity assessments within an adolescent population (aged 15 - 18 years): body mass index (BMI), visceral fat ratio measured with an MRI and hepatorenal gradient measured with an ultrasound. Volunteers also underwent an MRI scan to measure brain structure. Results indicated that there was no relationship of BMI or hepatorenal gradient with brain cortical dimensions. However, there was a significant association between visceral fat ratio and an increase of cortical thickness throughout the brain. These results suggest that visceral fat, but not BMI, is correlated with cortical thickening in adolescence. © 2016 World Obesity Federation.

  5. Beam Test Results for MSGC's with Thick Metal Strips.

    CERN Document Server

    Beaumont, W; Bernier, K; Bouhali, O; Boulogne, I; Daubie, Evelyne; De Troy, J G; Delentdecker, G; Devroede, O; Gregoire,,; Iacopi, F; Udo, Fred; Van Doninck, W K; Van Dyck, C; Van Lancker, L; Van der Velde, C; Verbeure, F; Zhukov, V

    1999-01-01

    Micro Strip Gas Counters with robust gold strips have been developed at IMEC, the Interuniversity Microelectronics Center at Leuven, in Belgium. The electroless plating technology was used, allowing to achieve a strip thickness of up to 1.6 mu m on 10 X 10 cm**2 substrates. Results on signal to noise ratio, spark rate, resulting damages and detector occupancy are presented for counters exposed to various intensities of heavily ionizing particles.

  6. Spreading of oil and the concept of average oil thickness

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, R. [Innovative Ventures Ltd., Cochrane, AB (Canada); Quintero-Marmol, A.M. [Pemex E and P, Campeche (Mexico); Bannerman, K. [Radarsat International, Vancouver, BC (Canada); Stevenson, G. [Calgary Univ., AB (Canada)

    2004-07-01

    The area of on oil slick on water can be readily measured using simple techniques ranging from visual observations to satellite-based radar systems. However, it is necessary to know the volume of spilled oil in order to determine the environmental impacts and best response strategy. The volume of oil must be known to determine spill quantity, response effectiveness and weathering rates. The relationship between volume and area is the average thickness of the oil over the spill area. This paper presents the results of several experiments conducted in the Gulf of Mexico that determined if average thickness of the oil is a characteristic of a specific crude oil, independent of spill size. In order to calculate the amount of oil on water from the area of slick requires information on the oil thickness, the inhomogeneity of the oil thickness and the oil-to-water ratio in the slick if it is emulsified. Experimental data revealed that an oil slick stops spreading very quickly after the application of oil. After the equilibrium thickness has been established, the slick is very sensitive to disturbances on the water surface, such as wave action, which causes the oil circle to dissipate into several small irregular shapes. It was noted that the spill source and oceanographic conditions are both critical to the final shape of the spill. 31 refs., 2 tabs., 8 figs.

  7. New layer thickness parameterization of diffusive convection in the ocean

    Science.gov (United States)

    Zhou, Sheng-Qi; Lu, Yuan-Zheng; Song, Xue-Long; Fer, Ilker

    2016-03-01

    In the present study, a new parameterization is proposed to describe the convecting layer thickness in diffusive convection. By using in situ observational data of diffusive convection in the lakes and oceans, a wide range of stratification and buoyancy flux is obtained, where the buoyancy frequency N varies between 10-4 and 0.1 s-1 and the heat-related buoyancy flux qT varies between 10-12 and 10-7 m2 s-3. We construct an intrinsic thickness scale, H0 =[qT3 / (κTN8) ] 1 / 4, here κT is the thermal diffusivity. H0 is suggested to be the scale of an energy-containing eddy and it can be alternatively represented as H0 = ηRebPr1/4, here η is the dissipation length scale, Reb is the buoyant Reynolds number, and Pr is the Prandtl number. It is found that the convective layer thickness H is directly linked to the stability ratio Rρ and H0 with the form of H ∼ (Rρ - 1)2H0. The layer thickness can be explained by the convective instability mechanism. To each convective layer, its thickness H reaches a stable value when its thermal boundary layer develops to be a new convecting layer.

  8. 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.

  9. Effect of Film Thickness on Properties of a-Si∶H Films

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The a-Si∶H films with different thickness smaller than 1μm were deposited by plasma enhanced chemical vapor deposition (PECVD) under the optimum deposition conditions. The effect of different thickness on film properties is analyzed.The results show that,with the increase of the film thickness,the dark conductivity, photoconductivity and threshold voltage increase, the optical gap and peak ratio of TA to TO in the Raman spectra decrease, the refractive index keeps almost constant, and the optical absorption coefficient and current ratio of on/off state first maximize and then reduce.

  10. Thickness measurement of GaN epilayer using high resolution X-ray diffraction technique

    Institute of Scientific and Technical Information of China (English)

    冯淦; 朱建军; 沈晓明; 张宝顺; 赵德刚; 王玉田; 杨辉; 梁骏吾

    2003-01-01

    In this paper we propose a new method for measuring the thickness of the GaN epilayer, by using the ratio of the integrated intensity of the GaN epilayer X-ray diffraction peaks to that of the sapphire substrate ones. This ratio shows a linear dependence on the GaN epilayer thickness up to 2 μm. The new method is more accurate and convenient than those of using the relationship between the integrated intensity of GaN epilayer diffraction peaks and the GaN thickness. Besides, it can eliminate the absorption effect of the GaN epilayer.

  11. Effects of Thickness Deviation of Elastic Plates in Multi-Layered Resonance Systems on Frequency Spectra

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui; ZHANG Shu-Yi; FAN Li

    2009-01-01

    A model of high-overtone bulk acoustic resonators is used to study the effects of thickness deviation of elastic plates on resonance frequency spectra in planar multi-layered systems. The resonance frequency shifts induced by the thickness deviations of the elastic plates periodically vary with the resonance order, which depends on the acoustic impedance ratios of the elastic plates to piezoelectric patches. Additionally, the center lines of the frequency shift oscillations Hnearly change with the orders of the resonance modes, and their slopes are sensitive to the thickness deviations of the plates, which can be used to quantitatively evaluate the thickness deviations.

  12. Thick Presentism and Newtonian Mechanics

    CERN Document Server

    Lubashevsky, Ihor

    2016-01-01

    In the present paper I argue that the formalism of Newtonian mechanics stems directly from the general principle to be called the principle of microlevel reducibility which physical systems obey in the realm of classical physics. This principle assumes, first, that all the properties of physical systems must be determined by their states at the current moment of time, in a slogan form it is "only the present matters to physics." Second, it postulates that any physical system is nothing but an ensemble of structureless particles arranged in some whose interaction obeys the superposition principle. I substantiate this statement and demonstrate directly how the formalism of differential equations, the notion of forces in Newtonian mechanics, the concept of phase space and initial conditions, the principle of least actions, etc. result from the principle of microlevel reducibility. The philosophical concept of thick presentism and the introduction of two dimensional time---physical time and meta-time that are mut...

  13. 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.

  14. 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.

  15. Macular thickness and volume in the elderly

    DEFF Research Database (Denmark)

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

    2016-01-01

    manifests in the macula of the elderly focusing on clinical relevant measures that are thicknesses and volumes of different macular areas. Ageing seems to increase center point foveal thickness. Ageing does not seem to change the center subfield thickness significantly. Ageing decreases the inner and outer...

  16. [The thickness/radius ratio of the left ventricle in aortic stenosis. Prognostic and therapeutic implications].

    Science.gov (United States)

    Guadalajara, J F; Martínez, C; Huerta, D

    1990-01-01

    Using two-D echocardiography and cardiac catheterization we studied the performance of left ventricle in severe aortic stenosis with normal ventricular function (10 patients), and with heart failure (11 patients). With appropriate hypertrophy increased ventricular function, is found resulting in systolic wall stress normalization. When hypertrophic mechanism is unable to normalize the systolic wall stress; afterload increases with ensuing heart failure (inadequate hypertrophy). Surgical treatment in those cases reduces the afterload and increases de ventricular function. Normalization of systolic wall stress in patients with severe aortic stenosis and heart failure means irreversible myocardial damage.

  17. 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.

  18. Non-linear dynamics of inlet film thickness during unsteady rolling process

    Science.gov (United States)

    Fu, Kuo; Zang, Yong; Gao, Zhiying; Qin, Qin; Wu, Diping

    2016-05-01

    The inlet film thickness directly affects film and stress distribution of rolling interfaces. Unsteady factors, such as unsteady back tension, may disturb the inlet film thickness. However, the current models of unsteady inlet film thickness lack unsteady disturbance factors and do not take surface topography into consideration. In this paper, based on the hydrodynamic analysis of inlet zone an unsteady rolling film model which concerns the direction of surface topography is built up. Considering the small fluctuation of inlet angle, absolute reduction, reduction ratio, inlet strip thickness and roll radius as the input variables and the fluctuation of inlet film thickness as the output variable, the non-linear relationship between the input and output is discussed. The discussion results show that there is 180° phase difference between the inlet film thickness and the input variables, such as the fluctuant absolute reduction, the fluctuant reduction ratio and non-uniform inlet strip thickness, but there is no phase difference between unsteady roll radius and the output. The inlet angle, the steady roll radius and the direction of surface topography have significant influence on the fluctuant amplitude of unsteady inlet film thickness. This study proposes an analysis method for unsteady inlet film thickness which takes surface topography and new disturbance factors into consideration.

  19. Tau hadronic branching ratios

    CERN Document Server

    Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Ariztizabal, F; Chmeissani, M; Crespo, J M; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Gaitan, V; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Engelhardt, A; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Markou, C; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wiedenmann, W; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Bardadin-Otwinowska, Maria; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Saadi, F; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Kyriakis, A; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Passalacqua, L; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Delfino, M C; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Pepé-Altarelli, M; Dorris, S J; Halley, A W; ten Have, I; Knowles, I G; Lynch, J G; Morton, W T; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Smith, M G; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Braun, O; Geweniger, C; Graefe, G; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Colling, D J; Dornan, Peter J; Konstantinidis, N P; Moneta, L; Moutoussi, A; Nash, J; San Martin, G; Sedgbeer, J K; Stacey, A M; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Raab, J; Renk, B; Sander, H G; Wanke, R; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Thulasidas, M; Nicod, D; Payre, P; Rousseau, D; Talby, M; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Brown, D; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wolf, G; Alemany, R; Boucrot, J; Callot, O; Cordier, A; Courault, F; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Musolino, G; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Abbaneo, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Triggiani, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Mir, L M; Perrodo, P; Strong, J A; Bertin, V; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Edwards, M; Maley, P; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Cartwright, S L; Combley, F; Dawson, I; Köksal, A; Letho, M; Newton, W M; Rankin, C; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

    1996-01-01

    From 64492 selected \\tau-pair events, produced at the Z^0 resonance, the measurement of the tau decays into hadrons from a global analysis using 1991, 1992 and 1993 ALEPH data is presented. Special emphasis is given to the reconstruction of photons and \\pi^0's, and the removal of fake photons. A detailed study of the systematics entering the \\pi^0 reconstruction is also given. A complete and consistent set of tau hadronic branching ratios is presented for 18 exclusive modes. Most measurements are more precise than the present world average. The new level of precision reached allows a stringent test of \\tau-\\mu universality in hadronic decays, g_\\tau/g_\\mu \\ = \\ 1.0013 \\ \\pm \\ 0.0095, and the first measurement of the vector and axial-vector contributions to the non-strange hadronic \\tau decay width: R_{\\tau ,V} \\ = \\ 1.788 \\ \\pm \\ 0.025 and R_{\\tau ,A} \\ = \\ 1.694 \\ \\pm \\ 0.027. The ratio (R_{\\tau ,V} - R_{\\tau ,A}) / (R_{\\tau ,V} + R_{\\tau ,A}), equal to (2.7 \\pm 1.3) \\ \\%, is a measure of the importance of Q...

  20. Effects of mode coupling on the admittance of an AT-cut quartz thickness-shear resonator

    Institute of Scientific and Technical Information of China (English)

    He Hui-Jing; Yang Jia-Shi; Zhang Wei-Ping; Wang Ji

    2013-01-01

    We study the effects of couplings to flexure and face-shear modes on the admittance of an AT-cut quartz plate thickness-shear mode resonator.Mindlin's two-dimensional equations for piezoelectric plates are employed.Electrically forced vibration solutions are obtained for three cases:pure thickness-shear mode alone; two coupled modes of thickness shear and flexure; and three coupled modes of thickness shear,flexure,and face shear.Admittance is calculated and its dependence on the driving frequency and the length/thickness ratio of the resonator is examined.Results show that near the thickness-shear resonance,admittance assumes maxima,and that for certain values of the length/thickness ratio,the coupling to flexure causes severe admittance drops,while the coupling to the face-shear mode causes additional admittance changes that were previously unknown and hence are not considered in current resonator design practice.

  1. Peripapillary choroidal thickness in healthy Chinese subjects

    Science.gov (United States)

    2013-01-01

    Background To evaluate the peripapillary choroidal thickness of a healthy Chinese population, and to determine its influencing factors. Methods A total of 76 healthy volunteers (76 eyes) without ophthalmic or systemic symptoms were enrolled. Choroidal scans (360-degree 3.4 mm diameter peripapillary circle scans) were obtained for all eyes using enhanced depth imaging spectral-domain optical coherence tomography. Choroid thickness was measured at the temporal, superotemporal, superior, superonasal, nasal, inferonasal, inferior, and inferotemporal segments. Results The average peripapillary choroidal thicknesses were 165.03 ± 40.37 μm. Inferonasal, inferior, and inferotemporal thicknesses were significantly thinner than temporal, superotemporal, superior, superonasal, nasal thicknesses (p thicknesses. The average peripapillary choroidal thickness decreased linearly with age (β = −1.33, 95% CI −1.98, -0.68, P choroidal thickness and other factors (gender, refractive error, axial length, average retinal nerve fiber layer thickness, intraocular pressure, diastolic blood pressure, systolic blood pressure, mean blood pressure, diastolic ocular perfusion pressure, systolic ocular perfusion pressure, and mean ocular perfusion pressure). Conclusions The inferonasal, inferior, inferotemporal peripapillary choroidal thicknesses were significantly thinner than temporal, superotemporal, superior, superonasal, and nasal thicknesses. A thinner peripapillary choroid is associated with increasing age. PMID:23758729

  2. Investigation of high thickness holographic gratings in acrylamide-based photopolymer

    Science.gov (United States)

    Wang, Heng; Xu, Shifeng; Ma, Jia; Wang, Zhaoyang; Hou, Enzhu

    2016-11-01

    We studied the holographic characteristics of acrylamide-based photopolymer layers ranging in thickness from 300 μm to 1000 μm. Scattering patterns of various materials were presented, and both transmittance and scattering ratio were measured. Then, theoretical and experimental Bragg selectivity curves of two samples with thicknesses of 300 μm and 510 μm were analyzed, demonstrating the effective optical thickness inside photopolymer, which was responsible for the width of Bragg selectivity curve. Through the simulation for the spatial dynamics of refractive index distribution inside materials with different thicknesses, the attenuation of grating along the direction of thickness inside photopolymer was presented. Moreover, the photo-induced polymer chain length was evaluated, and a growing tendency of polymer chain length as increasing depth of material thickness was presented for the first time, in other words, there were polymers with longer chain length in deeper layer of material.

  3. Thickness monitor for floated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Ricketts, J.; Grecu, G.M.

    1989-10-31

    This patent describes apparatus for determining the thickness of a layer of aerated sludge floating on a layer of a heavier liquid in a tank. It comprises: a frame means which can be positioned to extend vertically into the tank; horizontally-extending indicator means supported by and moveable vertically with respect to a portion of the frame means extending vertically into the tank. The indicator means being selectively positionable at the highest level of sludge in the tank; horizontally-extending lower base means attached to the frame means at or near the bottom thereof; horizontally-extending upper base means attached to the frame means at or near the top thereof; and a line carrying a float means. The line being movable secured at the upper base means and the lower base means. The float means being floatable on the liquid and including a horizontally-extending portion presenting an upwardly directed generally planar surface, which surface will be parallel to the interface of the sludge and liquid.

  4. Research on New Method of Full-Seam Mining for Gently Inclined Thick Coal Seams

    Institute of Scientific and Technical Information of China (English)

    赵景礼; 郭志飙; 柳慧鹏; 赵立军

    2002-01-01

    The recovery ratio of top-coal caving mining plays a key role in the development of this mining method. For the proposes to raise the recovery ratio and considering heading advance and roadway maintenance, a new method of full - seam mining for gently inclined thick coal seams is put forward on the basis of a theoretic research and engineering practice.

  5. Study of the effect of membrane thickness on microcapsule strength, permeability, and cell proliferation.

    Science.gov (United States)

    Ma, Ying; Zhang, Ying; Wang, Yu; Wang, Qiuyan; Tan, Mingqian; Liu, Yang; Chen, Li; Li, Na; Yu, Weiting; Ma, Xiaojun

    2013-04-01

    Cell microencapsulation is one of the promising strategies for in vitro production of proteins or in vivo delivery of therapeutic products. Membrane thickness controls microcapsule strength and permeability, which may in return affect cell growth and metabolism. In this study, the strength, permeability, and encapsulated Chinese hamster ovary cell proliferation and metabolism of four groups of microcapsules with different membrane thicknesses were investigated. It was found that increasing membrane thickness increases microcapsule strength, whereas decreases membrane permeability. During the first 6 days, cells within microcapsules with 10 μm thickness membrane proliferated fast and could reach a cell density of 1.9 × 10(7) cells/mL microcapsule with 92% cell density. A cell density of 5.5 × 10(7) cells/mL microcapsule with >85% cell density was achieved within microcapsules with 15 μm membrane thickness and these microcapsules kept over 88% integrity ratio after 11 days, which was much higher than that of microcapsules with 10 μm membrane thickness. Membrane with more than 20 μm thickness was not suited for encapsulated cell culture owing to low-protein diffusion rate. These results indicated that cells survived shortly within the thinnest membrane thickness. There was a specific membrane thickness more suitable for cell growth for a long-time culture. These findings will be useful for preparing microcapsules with the desired membrane thickness for microencapsulated cell culture dependent on various purposes.

  6. Oceanic Double-Diffusive Layer Thicknesses in the Presence of Turbulence

    Science.gov (United States)

    Shibley, Nicole; Timmermans, Mary-Louise

    2016-11-01

    Double-diffusive stratification in the ocean is characterized by staircase structures consisting of mixed layers separated by high-gradient interfaces in temperature and salinity. Several past studies have examined mechanisms that govern the observed thicknesses of staircase mixed layers. In one formalism, the mixed-layer thickness is set by layer formation that arises when a heat source is applied at the base of water that is stably-stratified in salinity; in another, the equilibrium thickness of mixed layers has been explained as the product of "merging," where thin layers continue to grow until they reach a thickness determined by a criterion relating the ratio of heat flux to salt flux and the density ratio. We extend the above two theories to consider the influence of turbulence on mixed-layer thicknesses. The study has implications for the Arctic Ocean where double-diffusive staircases are widely present, and mixed-layer thicknesses are well-resolved by ocean measurements. Our theoretical framework provides a means to determine turbulent diffusivities (in regions where microstructure measurements are not available) by considering only observations of density ratio, stratification, and layer thicknesses.

  7. CHOROIDAL MORPHOLOGY IN EYES WITH POLYPOIDAL CHOROIDAL VASCULOPATHY AND NORMAL OR SUBNORMAL SUBFOVEAL CHOROIDAL THICKNESS.

    Science.gov (United States)

    Lee, Won Ki; Baek, Jiwon; Dansingani, Kunal K; Lee, Jae Hyung; Freund, K Bailey

    2016-12-01

    To subsegment the choroid in patients with polypoidal choroidal vasculopathy and to determine whether the ratio of choriocapillaris/Sattler layer thickness to total choroidal thickness is decreased at sites of polypoidal pathology. Retrospective, observational, cross-sectional study. A total of 320 eyes of 305 patients with polypoidal choroidal vasculopathy were studied with optical coherence tomography and dye angiography. The ratio of choriocapillaris/Sattler layer thickness to total choroidal thickness was calculated at polypoidal lesion sites in eyes with subfoveal choroidal thickness (SFCT) ≤200 μm. Mean SFCT was 267.7 ± 118.5 μm for the entire cohort. Mean SFCT was 151.2 ± 35.0 μm in eyes with SFCT ≤200 μm (n = 124, 39%). In this subgroup, dilated Haller vessels (pachyvessels) were identified under the site of neovascular ingrowth in 117 eyes (94%). Choroidal thickness in the pachyvessel zone was greater (213.3 ± 52.2 μm) than SFCT (P thickness ratio (P choroidal thickening at sites of polypoidal disease. The choriocapillaris and Sattler layers were attenuated at these locations, but Haller vessels were markedly dilated. These changes were topographically associated with sites of neovascular ingrowth and support the classification of polypoidal choroidal vasculopathy as a pachychoroid disorder.

  8. High-Ratio Gear Train

    Science.gov (United States)

    Lefever, A. E.

    1982-01-01

    Proposed arrangement of two connected planetary differentials results in gear ratio many times that obtainable in conventional series gear assembly of comparable size. Ratios of several thousand would present no special problems. Selection of many different ratios is available with substantially similar gear diameters. Very high gear ratios would be obtained from small mechanism.

  9. Thickness of residual wetting film in liquid-liquid displacement

    Science.gov (United States)

    Beresnev, Igor; Gaul, William; Vigil, R. Dennis

    2011-08-01

    Core-annular flow is common in nature, representing, for example, how streams of oil, surrounded by water, move in petroleum reservoirs. Oil, typically a nonwetting fluid, tends to occupy the middle (core) part of a channel, while water forms a surrounding wall-wetting film. What is the thickness of the wetting film? A classic theory has been in existence for nearly 50 years offering a solution, although in a controversial manner, for moving gas bubbles. On the other hand, an acceptable, experimentally verified theory for a body of one liquid flowing in another has not been available. Here we develop a hydrodynamic, testable theory providing an explicit relationship between the thickness of the wetting film and fluid properties for a blob of one fluid moving in another, with neither phase being gas. In its relationship to the capillary number Ca, the thickness of the film is predicted to be proportional to Ca2 at lower Ca and to level off at a constant value of ˜20% the channel radius at higher Ca. The thickness of the film is deduced to be approximately unaffected by the viscosity ratio of the fluids. We have conducted our own laboratory experiments and compiled experimental data from other studies, all of which are mutually consistent and confirm the salient features of the theory. At the same time, the classic law, originally deduced for films surrounding moving gas bubbles but often believed to hold for liquids as well, fails to explain the observations.

  10. Effects of PCB thickness on adjustable fountain wave soldering

    Indian Academy of Sciences (India)

    M S Abdul Aziz; M Z Abdullah; C Y Khor; A Jalar; M A Bakar; W Y W Yusoff; F Che Ani; Nobe Yan; M Zhou; C Cheok

    2015-10-01

    This study investigates the effects of printed circuit board (PCB) thickness on adjustable fountain and conventional wave soldering. The pin-through-hole (PTH) vertical fill is examined with three PCBs of different thicknesses (i.e., 1.6, 3.1, and 6.0 mm) soldered through adjustable fountain and conventional wave soldering at conveyor angles of 0° and 6°. The vertical fill of each PCB is the focus. The PTH solder profile is inspected with a non-destructive X-ray computed tomography scanning machine. The percentages of the PTH vertical fill of both soldering processes are also estimated and compared. The aspect ratio of the PCB is also investigated. Experimental results reveal that adjustable fountain wave soldering yields better vertical fill than conventional wave soldering. The vertical fill level of adjustable fountain wave soldering is 100%, 90%, and 50% for the 1.6, 3.1, and 6.0 mm PCB thickness, respectively. FLUENT simulation is conducted for the vertical fill of the solder profile. Simulation and experimental results show that the PTH solder profiles of the two soldering processes are almost identical. The effect of PCB thickness on PTH voiding is also discussed.

  11. 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.

  12. Ice thickness measurements by Raman scattering

    CERN Document Server

    Pershin, Sergey M; Klinkov, Vladimir K; Yulmetov, Renat N; Bunkin, Alexey F

    2014-01-01

    A compact Raman LIDAR system with a spectrograph was used for express ice thickness measurements. The difference between the Raman spectra of ice and liquid water is employed to locate the ice-water interface while elastic scattering was used for air-ice surface detection. This approach yields an error of only 2 mm for an 80-mm-thick ice sample, indicating that it is promising express noncontact thickness measurements technique in field experiments.

  13. A study of microclad thickness variation (1987)

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, R.S.; Armstrong, K.P.

    1989-06-22

    A study was conducted to investigate the thickness variation of microclad material used in fabricating 1E38 bridges. For the role sampled (nine reels), standard deviations within reels ranged from 6.11 to 12.07 {mu}in. Thickness variations within reels ranged from 16.2 to 40.9 {mu}in., with the average thickness between 142.90 and 161.28 {mu}in.

  14. Probing the neutron skin thickness in collective modes of excitation

    Directory of Open Access Journals (Sweden)

    Paar N.

    2014-03-01

    Full Text Available Nuclear collective motion provides valuable constraint on the size of neutron-skin thickness and the properties of nuclear matter symmetry energy. By employing relativistic nuclear energy density functional (RNEDF and covariance analysis related to χ2 fitting of the model parameters, relevant observables are identified for dipole excitations, which strongly correlate with the neutron-skin thickness (rnp, symmetry energy at saturation density (J and slope of the symmetry energy (L. Using the RNEDF framework and experimental data on pygmy dipole strength (68Ni, 132Sn, 208Pb and dipole polarizability (208Pb, it is shown how the values of J, and L, and rnp are constrained. The isotopic dependence of moments associated to dipole excitations in 116–136Sn shows that the low-energy dipole strength and polarizability in neutron-rich nuclei display strong sensitivity to the symmetry energy parameter J, more pronounced than in isotopes with moderate neutron-to-proton number ratios.

  15. Axisymmetric buckling of laminated, moderately thick shallow conical cap

    Energy Technology Data Exchange (ETDEWEB)

    Dumir, P.C.; Dube, G.P.; Joshi, S. [Applied Mechanics Dept., I.I.T. Delhi, New Delhi (India)

    2001-05-01

    Axisymmetric buckling and postbuckling analysis is presented for a moderately thick, laminated shallow conical cap under static transverse load. Marguerre-type, first-order shear deformation shallow-shell theory is formulated in terms of transverse deflection w, the rotation {psi} of the normal to the midsurface and the stress function {phi}. The governing equations are solved by the orthogonal point-collocation method. Clamped conical caps and simple supports with movable and immovable edge conditions are considered. Typical numerical results are presented, illustrating the effect of various parameters. The dependence of the effect of the shear deformation on the thickness parameter, boundary conditions, ratio of Young's moduli and cap height is investigated. (orig.)

  16. Vibrations of moderately thick shallow spherical shells at large amplitudes

    Science.gov (United States)

    Sathyamoorthy, M.

    1994-04-01

    A shallow shell theory is presented for the geometrically nonlinear analysis of moderately thick isotropic spherical shells. Effects of transverse shear deformation and rotatory inertia are included in the governing equations of motion by means of tracing constants. When these effects are ignored, the governing equations readily reduce to those applicable for thin shallow spherical shells. Solutions to the system of thick shell equations are obtained by means of Galerkin's method and the numerical Runge-Kutta procedure. Numerical results are presented for certain cases of shallow spherical shells considering different geometric shell parameters. Transverse shear and rotatory inertia effects are found to be important in linear as well as nonlinear responses of shallow spherical shells. The nonlinear frequency-amplitude behavior is of the softening type for shallow spherical shells and of the hardening type for circular plates. Frequency ratios are lower at any given amplitude when the effects of transverse shear and rotatory inertia are included in the analysis.

  17. Efficiency of nonstandard and high contact ratio involute spur gears

    Science.gov (United States)

    Anderson, N. E.; Loewenthal, S. H.

    1986-01-01

    A power loss prediction was extended to include involute spur gears of nonstandard proportions. The method is used to analyze the effects of modified addendum, tooth thickness, and gear center distance in addition to the parameters previously considered which included gear diameter, pitch, pressure angle, face width, oil viscosity, speed, and torque. Particular emphasis was placed on high contact ratio gearing (contact ratios greater than two). Despite their higher sliding velocities, high contact ratio gears are designed to levels of efficiency comparable to those of conventional gears while retaining their advantages through proper selection of gear geometry.

  18. Determination of Thickness of an Inaccessible Thin Film under a Multilayered System from Natural Frequencies

    Institute of Scientific and Technical Information of China (English)

    ZHOU Chang-Zhi; LI Ming-Xuan; MAO Jie; WANG Xiao-Min

    2008-01-01

    @@ We investigate the relationship between natural frequencies of a multilayered system of different elastic materials and the thickness of the undermost thin film. The natural frequencies are numerically calculated from the reflection coefficient of a sample system of "steel-epoxy resin-aluminium-thin polymer' with normal incidence.Strain energy ratio is defined and calculated to give the physics explanation why some frequencies are sensitive to thickness of the thin film in certain range. Experiments of three specimens indicate that the measured natural frequencies agree well with the theoretical ones. It is found in our experiments that the ratio of the lowest film thickness to wavelength is about 1/5. The average relative errors for the inverted polymer film thicknesses are found to be 11.8%, -4.8% and -1.3%, respectively.

  19. Choroidal thickness profile in healthy Indian children.

    Science.gov (United States)

    Chhablani, Jay Kumar; Deshpande, Riddhima; Sachdeva, Virender; Vidya, Sagar; Rao, P Srinivasa; Panigati, Anand; Mahat, Birendra; Pappuru, Rajeev Reddy; Pehere, Niranjan; Pathengay, Avinash

    2015-06-01

    The purpose was to study choroidal thickness and its profile based on location in healthy Indian children using enhanced depth spectral-domain-optical coherence tomography (SD-OCT). In this cross-sectional observational study 255 eyes of 136 children with no retinal or choroidal disease were consecutively scanned using enhanced depth SD-OCT. Eyes with any ocular disease or axial length (AXL) >25 mm or choroidal thickness from the posterior edge of the retinal pigment epithelium to the choroid/sclera junction at 500-microns intervals up to 2500 microns temporal and nasal to the fovea. Generalized estimating equations were used to evaluate the correlation between choroidal thickness at various locations and age, AXL, gender and spherical equivalent (SEq). Mean age of the subjects was 11.9 ± 3.4 years (range: 5-18 years). There were 62 Females and 74 males. The mean AXL was 23.55 ± 0.74 mm. Mean subfoveal choroidal thickness was 312.1 ± 45.40 μm. Choroid was found to be thickest subfoveally, then temporally. Age, AXL and SEq showed a significant correlation with choroidal thickness, whereas gender did not affect choroidal thickness. Our study provides a valid normative database of choroidal thickness in healthy Indian children. This database could be useful for further studies evaluating choroidal changes in various chorioretinal disorders. Age and AXL are critical factors, which negatively correlated with choroidal thickness.

  20. Dielectrophoretic capture of low abundance cell population using thick electrodes

    Science.gov (United States)

    Marchalot, Julien; Chateaux, Jean-François; Faivre, Magalie; Mertani, Hichem C.; Ferrigno, Rosaria; Deman, Anne-Laure

    2015-01-01

    Enrichment of rare cell populations such as Circulating Tumor Cells (CTCs) is a critical step before performing analysis. This paper presents a polymeric microfluidic device with integrated thick Carbon-PolyDimethylSiloxane composite (C-PDMS) electrodes designed to carry out dielectrophoretic (DEP) trapping of low abundance biological cells. Such conductive composite material presents advantages over metallic structures. Indeed, as it combines properties of both the matrix and doping particles, C-PDMS allows the easy and fast integration of conductive microstructures using a soft-lithography approach while preserving O2 plasma bonding properties of PDMS substrate and avoiding a cumbersome alignment procedure. Here, we first performed numerical simulations to demonstrate the advantage of such thick C-PDMS electrodes over a coplanar electrode configuration. It is well established that dielectrophoretic force (FDEP) decreases quickly as the distance from the electrode surface increases resulting in coplanar configuration to a low trapping efficiency at high flow rate. Here, we showed quantitatively that by using electrodes as thick as a microchannel height, it is possible to extend the DEP force influence in the whole volume of the channel compared to coplanar electrode configuration and maintaining high trapping efficiency while increasing the throughput. This model was then used to numerically optimize a thick C-PDMS electrode configuration in terms of trapping efficiency. Then, optimized microfluidic configurations were fabricated and tested at various flow rates for the trapping of MDA-MB-231 breast cancer cell line. We reached trapping efficiencies of 97% at 20 μl/h and 78.7% at 80 μl/h, for 100 μm thick electrodes. Finally, we applied our device to the separation and localized trapping of CTCs (MDA-MB-231) from a red blood cells sample (concentration ratio of 1:10). PMID:26392836

  1. Harvesting split thickness costal cartilage graft

    Directory of Open Access Journals (Sweden)

    Sunil Gaba

    2017-01-01

    Full Text Available Aim: There are few complications associated with harvesting of full thickness coastal cartilage grafts i.e., pneumothorax (0.9%, contour deformities and prolonged post-operative pain. To address these issues, authors devised special scalpel to harvest split-thickness costal cartilage grafts. Materials and Methods: Standard inframammary incision was used for harvesting rib. Incision was made directly over the desired rib. Specially designed scalpel was used to cut through the rib cartilage to the half of the thickness. The study was conducted in two parts – cadaveric and clinical. Results: There was significantly less pain and no pneumothorax in the patients in whom the split thickness graft was harvested. Wounds healed without any complication. Discussion: Thus, newly devised angulated scalpel used in the current study, showed the potential to supply the reconstructive surgeon with split thickness rib graft without risk of complications such as pneumothorax or warping contour deformities and post-operative pain.

  2. The thickness of amalgamations of graphs

    CERN Document Server

    Yang, Yan

    2012-01-01

    The thickness $\\theta(G)$ of a graph $G$ is the minimum number of planar spanning subgraphs into which the graph $G$ can be decomposed. As a topological invariant of a graph, it is a measurement of the closeness to planarity of a graph, and it also has important applications to VLSI design. In this paper, the thickness of graphs that are obtained by vertex-amalgamation and bar-amalgamation of any two graphs whose thicknesses are known are obtained, respectively. And the lower and upper bounds for the thickness of graphs that are obtained by edge-amalgamation and 2-vertex-amalgamation of any two graphs whose thicknesses are known are also derived, respectively.

  3. Micro-droplets lubrication film thickness dynamics

    Science.gov (United States)

    Huerre, Axel; Theodoly, Olivier; Cantat, Isabelle; Leshansky, Alexander; Valignat, Marie-Pierre; Jullien, Marie-Caroline; MMN Team; LAI Team; IPR Team; Department of Chemical Engineering Team

    2014-11-01

    The motion of droplets or bubbles in confined geometries has been extensively studied; showing an intrinsic relationship between the lubrication film thickness and the droplet velocity. When capillary forces dominate, the lubrication film thickness evolves non linearly with the capillary number due to viscous dissipation between meniscus and wall. However, this film may become thin enough that intermolecular forces come into play and affect classical scalings. We report here the first experimental evidence of the disjoining pressure effect on confined droplets by measuring droplet lubrication film thicknesses in a microfluidic Hele-Shaw cell. We find and characterize two distinct dynamical regimes, dominated respectively by capillary and intermolecular forces. In the former case rolling boundary conditions at the interface are evidenced through film thickness dynamics, interface velocity measurement and film thickness profile.

  4. Numerical Investigation on the Influence of Nozzle Lip Thickness on the Flow Field and Performance of an Annular Jet Pump

    Institute of Scientific and Technical Information of China (English)

    LongZhou Xiao; XinPing Long; XueLong Yang

    2014-01-01

    The performance of an annular jet pump ( AJP ) is determined by its area ratio A ( ratio of cross sectional area of throat and annular nozzle) and flow rate ratio q ( ratio of primary and secondary flow rate, Qs/Qj ) , while the nozzle lip thickness is neglected in the present studies. This paper presents a study on the effect of the thickness on the flow field and performance of an AJP with A = 1�75. With the increasing flow rate ratio and nozzle lip thickness, a small vortex forms at the nozzle lip and keeps on growing. However, as the flow rate ratio or nozzle lip thickness is extremely low, the vortex at the lip vanishes thoroughly. Moreover, the recirculation width varies conversely with the nozzle lip thickness when the flow rate ratio q≤0�13. While the deviation of the recirculation width with different nozzle lip thickness is negligible with q≥0�13. Additionally the existence of nozzle lip hinders the momentum exchange between the primary and secondary flow and leads to a mutation of velocity gradient near the nozzle exit, which shift the recirculation downstream. Finally, based on the numerical results of the streamwise and spanwise vortex distributions in the suction chamber, the characteristics of the mixing process and the main factors accounting for the AJP performance are clarified.

  5. Time-resolved photoresponse of nanometer-thick Nb/NiCu bilayers

    Science.gov (United States)

    Parlato, L.; Pepe, G. P.; Latempa, R.; De Lisio, C.; Altucci, C.; D'Acunto, P.; Peluso, G.; Barone, A.; Taneda, T.; Sobolewski, R.

    2005-07-01

    We present femtosecond optical time-resolved pump-probe investigations of superconducting hybrids structures consisting of Nb/NiCu bilayers with various thickness. Measurements performed on pure Nb and NiCu films are also given. The photoresponse experiments provide the quasiparticle relaxation times in bilayers of different thickness ratios. The study of the photoresponse as a function of the temperature reveals the spatial evolution of the superconductor order parameter across the bilayers.

  6. Development of Dual-light Path Monitoring System of Optical Thin-film Thickness

    Institute of Scientific and Technical Information of China (English)

    XU Shi-jun

    2005-01-01

    The accurate monitoring of optical thin-film thickness is a key technique for depositing optical thin-film. For existing coating equipments, which are low precision and automation level on monitoring thin-film thickness, a new photoelectric control and analysis system has been developed. In the new system, main techniques include a photoelectric system with dual-light path, a dual-lock-phase circuit system and a comprehensive digital processing-control-analysis system.The test results of new system show that the static and dynamic stabilities and the control precision of thin-film thickness are extremely increased. The standard deviation of thin-film thickness, which indicates the duplication of thin-film thickness monitoring, is equal to or less than 0.72%. The display resolution limit on reflectivity is 0.02 %. In the system, the linearity of drift is very high, and the static drift ratio approaches zero.

  7. Double sinusoidal phase modulating laser diode interferometer for thickness measurements of transparent plates

    Institute of Scientific and Technical Information of China (English)

    Dailin Li(李代林); Xiangzhao Wang(王向朝); Yingming Liu(刘英明)

    2004-01-01

    A double sinusoidal phase modulating (SPM) laser diode interferometer for thickness measurements of a transparent plate is presented. A carrier signal is given to the interference signal by using a piezoelectric transducer, and the SPM interferometry is applied to measure the thickness of a transparent plate. By combining the double-modulation technique with the Bessel function ratio method, the measurement error originating from light intensity fluctuations caused by the modulation current can be decreased greatly.The thicknesses of a glass parallel plate and a quartz glass are measured in real time, and the corresponding experimental results are also given.

  8. Ultrasonic Evaluation of the Lens Thickness to Axial Length Factor in Primary Closure Angle Glaucoma

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    Ultrasonic biometry was done in 232 normal eyes and 138 eyes with primary angle closure glaucoma (ACG), using Ultrascan Digital B System IV (10 MHz). The ratio between the lens thickness and the axial length (lens thickness to axial length factor, LAF) was evaluated as a biometric index for assessing the eye with primary ACG in Chinese. LAF of 2.00 was found to be ideal point of demarcation between ACG and normal eyes (i.e., lens thickness equals to 1/5 of axial length). It appears that LAF is helpful i...

  9. Novel attributes and design considerations of effective oxide thickness in nano DG MOSFETs

    Institute of Scientific and Technical Information of China (English)

    Morteza Charmi

    2015-01-01

    Impacts of effective oxide thickness on a symmetric double-gate MOSFET with 9-nm gate length are studied, using full quantum simulation. The simulations are based on a self-consistent solution of the two-dimensional (2D) Poisson equation and the Schr ¨odinger equation within the non-equilibrium Green’s function formalism. Oxide thickness and gate dielectric are investigated in terms of drain current, on-off current ratio, off current, sub-threshold swing, drain induced barrier lowering, transconductance, drain conductance, and voltage. Simulation results illustrate that we can improve the device performance by proper selection of the effective oxide thickness.

  10. Measurement of renal cortical thickness using spiral CT in early diabetic nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Bong Sig; Chung, Won Jung; Park, Byeong Ho; Choi, Jong Cheol; Nam, Kyung Jin; Lee, Yung Il; Chung, Duk Hwan [Donga Univ. College of Medicine, Pusan (Korea, Republic of)

    1997-03-01

    To compare the ratio of renal cortical thickness to renal parenchymal thickness in early diabetic nephropathy and in normal control group. We performed spiral CT in 17 patients suffering from diabetic nephropathy without renal failure or renal atrophy. The normal control group consisted of 19 persons who were normal on renal function test and did not show any abnormality of the kidney. Renal cortical and parenchymal thicknesses were measured at renal hilum level perpendicular to the renal surface by electronic caliper on contrast-enhanced transverse scan demonstrating the cortical nephrogram phase. Using student's test, the difference in renal parenchymal and cortical thickness between the two groups was tested for statistical significance. There was no significant difference in renal parenchymal thickness between the two groups (p>0.05);the patient group had a thicker renal cortex than the normal control group however (p<0.05). The ratio of renal cortical thickness to parenchymal thickness in early diabetic nephropathy patients (Rt.:0.041{+-}0.051, Lt.:0.382{+-}0.053) was significantly higher than in the normal control group (Rt.:0.331{+-}0.067, Lt.:0.323{+-}0.064). The kidney of early diabetic nephropathy patients had a thicker renal cortex than normal kidney.

  11. Translucency of dental ceramics with different thicknesses.

    Science.gov (United States)

    Wang, Fu; Takahashi, Hidekazu; Iwasaki, Naohiko

    2013-07-01

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

  12. Selective Withdrawal with an Inverted Viscosity Ratio

    Science.gov (United States)

    Case, Sarah

    2005-03-01

    In the selective withdrawal experiment, fluid is withdrawn, at rate Q, through a tube with its tip suspended a distance S above an unperturbed interface separating two immiscible fluids. For high Q, the lower fluid is entrained along with the upper one while for low Q only the upper fluid is withdrawn. We have studied the situation where the ratio of lower to the upper fluid viscosities, η>1. For low Q, the interface forms a steady-state hump and only the upper fluid is withdrawn. When Q is increased, or S is decreased, the interface undergoes a two-stage transition: first the hump forms an unsteady, thin spout which then expands into a second thicker steady-state structure with distinct flow patterns in the lower fluid. This thick-spout structure is not observed for ηCohen and S. R. Nagel, Phys. Rev. Lett. 88, 074501 1- 4 (2002).

  13. Film thickness determination by grazing incidence diffraction

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-09-01

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

  14. Manufacture of ultrasonic thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Ohba, Toshihiro; Yanagihara, Takao; Katoh, Chiaki; Hamada, Shozo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-09-01

    The demonstration test for evaluating reliability of the acid recovery evaporator at Rokkasho Reprocessing Plant has been carried out at JAERI. For the nondestructive measurement of the thickness of heat transfer tubes in the acid recovery evaporator and short tubes used in corrosion test, we have developed ultra sonic thickness measuring apparatus using immersion method with high resolution. This apparatus can measure and record tube thickness automatically with a personal computer. The results obtained by this apparatus are coincident with the results obtained by a destructive method using an optical microscope. (author)

  15. Refining thick brane models via electroweak data

    CERN Document Server

    Chumbes, A E R; Hott, M B

    2015-01-01

    After discussing the localization of Abelian and non-Abelian gauge fields and Higgs fields on a thick brane, we introduce a procedure of dimensional reduction and its consequences to the rescaled parameters of the boson sector of the Standard Model. The parameters encodes some power dependence on the extra dimension, usually narrow, warp factor and hence it also depend on the position related with the extra dimension inside the thick brane. In this vein, the observable parameters may be used to refine the braneworld models via the brane thickness.

  16. Ratiometric analysis of in vivo retinal layer thicknesses in multiple sclerosis

    Science.gov (United States)

    Bhaduri, Basanta; Nolan, Ryan M.; Shelton, Ryan L.; Pilutti, Lara A.; Motl, Robert W.; Boppart, Stephen A.

    2016-09-01

    We performed ratiometric analysis of retinal optical coherence tomography images for the first time in multiple sclerosis (MS) patients. The ratiometric analysis identified differences in several retinal layer thickness ratios in the cohort of MS subjects without a history of optic neuritis (ON) compared to healthy control (HC) subjects, and there was no difference in standard retinal nerve fiber layer thickness (RNFLT). The difference in such ratios between HC subjects and those with mild MS-disability, without a difference in RNFLT, further suggests the possibility of using layer ratiometric analysis for detecting early retinal changes in MS. Ratiometric analysis may be useful and potentially more sensitive for detecting disease changes in MS.

  17. Waves in initially stressed fluid-filled thick tubes.

    Science.gov (United States)

    Demiray, H

    1997-03-01

    In this paper, treating the artery as a thick walled cylindrical shell made of an incompressible, elastic and isotropic material and the blood as an incompressible inviscid fluid, by taking the inertia of the wall into account, the propagation of harmonic waves in an initially stressed tube, filled with an inviscid fluid, is studied. Utilizing inner-pressure-inner-cross-sectional-area relation in the linear momentum equation of the fluid, together with the continuity equation, we obtained two nonlinear equation governing the axial velocity and the cross-sectional area of the tube. Assuming that the dynamical motion superposed on large initial static deformation is small, a harmonic wave type of solution to incremental equations is sought and the dispersion relation is obtained as a function of transmural pressure, axial stretch, thickness ratio and the wave number. The wave speed is evaluated numerically for various materials and thickness/radius, and the results are depicted in graphical forms. The result indicates that, due to the inertial component of pressure, the wave is dispersive. The present formulation is compared with some previously published works.

  18. APPLIED ORIGAMI. Origami of thick panels.

    Science.gov (United States)

    Chen, Yan; Peng, Rui; You, Zhong

    2015-07-24

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

  19. Russian River Ice Thickness and Duration

    Data.gov (United States)

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

  20. Wilcox Group Apparent Thickness, Gulf Coast (wlcxthkg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Apparent Wilcox Group thickness maps are contoured from location and top information derived from the Petroleum Information (PI) Wells database. The Wilcox...

  1. Saturated thickness, High Plains aquifer, 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents the saturated thickness of the High Plains aquifer of the United States, 2009, in feet. The High Plains aquifer underlies...

  2. A database of worldwide glacier thickness observations

    DEFF Research Database (Denmark)

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

    2014-01-01

    One of the grand challenges in glacier research is to assess the total ice volume and its global distribution. Over the past few decades the compilation of a world glacier inventory has been well-advanced both in institutional set-up and in spatial coverage. The inventory is restricted to glacier...... surface observations. However, although thickness has been observed on many glaciers and ice caps around the globe, it has not yet been published in the shape of a readily available database. Here, we present a standardized database of glacier thickness observations compiled by an extensive literature...... review and from airborne data extracted from NASA's Operation IceBridge. This database contains ice thickness observations from roughly 1100 glaciers and ice caps including 550 glacier-wide estimates and 750,000 point observations. A comparison of these observational ice thicknesses with results from...

  3. Greenland Radar Ice Sheet Thickness Measurements

    Data.gov (United States)

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

  4. Definitions of radioisotope thick target yields

    Energy Technology Data Exchange (ETDEWEB)

    Otuka, Naohiko [International Atomic Energy Agency, Wien (Austria). Nuclear Data Section; Takacs, Sandor [Hungarian Academy of Science, Debrecen (Hungary). Inst. of Nuclear Research

    2015-05-01

    Definitions of thick target yields are reviewed in relation to their documentation for the experimental nuclear reaction data library (database). Researchers reporting experimental thick target yields are urged to define their yields clearly with an appropriate unit in order to compile them in the experimental data library (EXFOR) in a consistent manner, and also to properly utilise them for comparison with other experimental and evaluated yields.

  5. Choroidal thickness profile in healthy Indian children

    Directory of Open Access Journals (Sweden)

    Jay Kumar Chhablani

    2015-01-01

    Full Text Available Purpose: The purpose was to study choroidal thickness and its profile based on location in healthy Indian children using enhanced depth spectral-domain-optical coherence tomography (SD-OCT. Methods: In this cross-sectional observational study 255 eyes of 136 children with no retinal or choroidal disease were consecutively scanned using enhanced depth SD-OCT. Eyes with any ocular disease or axial length (AXL >25 mm or < 20 mm were excluded. A single observer measured choroidal thickness from the posterior edge of the retinal pigment epithelium to the choroid/sclera junction at 500-microns intervals up to 2500 microns temporal and nasal to the fovea. Generalized estimating equations were used to evaluate the correlation between choroidal thickness at various locations and age, AXL, gender and spherical equivalent (SEq. Results: Mean age of the subjects was 11.9 ± 3.4 years (range: 5-18 years. There were 62 Females and 74 males. The mean AXL was 23.55 ± 0.74 mm. Mean subfoveal choroidal thickness was 312.1 ± 45.40 μm. Choroid was found to be thickest subfoveally, then temporally. Age, AXL and SEq showed a significant correlation with choroidal thickness, whereas gender did not affect choroidal thickness. Conclusion: Our study provides a valid normative database of choroidal thickness in healthy Indian children. This database could be useful for further studies evaluating choroidal changes in various chorioretinal disorders. Age and AXL are critical factors, which negatively correlated with choroidal thickness.

  6. Choroidal thickness profiles in retinitis pigmentosa.

    Science.gov (United States)

    Ayton, Lauren N; Guymer, Robyn H; Luu, Chi D

    2013-01-01

    Little quantitative information exists regarding the effect that retinitis pigmentosa (RP) has on the choroid. The aim of this study was to determine choroidal thickness profiles in patients with RP. Prospective. Forty-two RP and 22 control subjects participated in the study. RP patients had mild to severe disease, with a visual acuity range of logMAR 0.1 to no light perception. Images of the retina and choroid were obtained using the enhanced depth-imaging method and optical coherence tomography (OCT). Choroidal thickness measures were determined via manual segmentation of the OCT image. The thickness profiles of the normal and RP groups were compared. The associations between choroidal thickness, visual acuity and duration of RP were determined. The choroid was thickest in the control eyes at the subfoveal location (336.60 ± 70.42 μm), and the thickness gradually decreased towards the peripheral retina (temporal 8° = 295.55 ± 60.52 μm; nasal 8° = 251.68 ± 49.93 μm). In RP, the mean thickness was also greater at the fovea (215.60 ± 94.91 μm) than the temporal (191.66 ± 72.42 μm) and nasal (149.91 ± 57.42 μm) retina, but all values were significantly lower than those of the controls (P ≤ 0.001). Subfoveal choroidal thickness was significantly correlated with visual acuity (r = -0.46, P choroid than controls. Patients with poorer visual acuity or longer duration of symptoms tended to have thinner choroids. Knowledge of choroidal thickness profile in RP is important for the field of restorative vision research and the development of suprachoroidal retinal prostheses. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

  7. Sex Ratio Elasticity Influences the Selection of Sex Ratio Strategy

    Science.gov (United States)

    Wang, Yaqiang; Wang, Ruiwu; Li, Yaotang; (Sam) Ma, Zhanshan

    2016-01-01

    There are three sex ratio strategies (SRS) in nature—male-biased sex ratio, female-biased sex ratio and, equal sex ratio. It was R. A. Fisher who first explained why most species in nature display a sex ratio of ½. Consequent SRS theories such as Hamilton’s local mate competition (LMC) and Clark’s local resource competition (LRC) separately explained the observed deviations from the seemingly universal 1:1 ratio. However, to the best of our knowledge, there is not yet a unified theory that accounts for the mechanisms of the three SRS. Here, we introduce the price elasticity theory in economics to define sex ratio elasticity (SRE), and present an analytical model that derives three SRSs based on the following assumption: simultaneously existing competitions for both resources A and resources B influence the level of SRE in both sexes differently. Consequently, it is the difference (between two sexes) in the level of their sex ratio elasticity that leads to three different SRS. Our analytical results demonstrate that the elasticity-based model not only reveals a highly plausible mechanism that explains the evolution of SRS in nature, but also offers a novel framework for unifying two major classical theories (i.e., LMC & LRC) in the field of SRS research. PMID:28009000

  8. Sex Ratio Elasticity Influences the Selection of Sex Ratio Strategy

    Science.gov (United States)

    Wang, Yaqiang; Wang, Ruiwu; Li, Yaotang; (Sam) Ma, Zhanshan

    2016-12-01

    There are three sex ratio strategies (SRS) in nature—male-biased sex ratio, female-biased sex ratio and, equal sex ratio. It was R. A. Fisher who first explained why most species in nature display a sex ratio of ½. Consequent SRS theories such as Hamilton’s local mate competition (LMC) and Clark’s local resource competition (LRC) separately explained the observed deviations from the seemingly universal 1:1 ratio. However, to the best of our knowledge, there is not yet a unified theory that accounts for the mechanisms of the three SRS. Here, we introduce the price elasticity theory in economics to define sex ratio elasticity (SRE), and present an analytical model that derives three SRSs based on the following assumption: simultaneously existing competitions for both resources A and resources B influence the level of SRE in both sexes differently. Consequently, it is the difference (between two sexes) in the level of their sex ratio elasticity that leads to three different SRS. Our analytical results demonstrate that the elasticity-based model not only reveals a highly plausible mechanism that explains the evolution of SRS in nature, but also offers a novel framework for unifying two major classical theories (i.e., LMC & LRC) in the field of SRS research.

  9. STEM tomography for thick biological specimens

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-12-15

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

  10. Rapid Measurement of Nanoparticle Thickness Profiles

    Energy Technology Data Exchange (ETDEWEB)

    Katz-Boon, Hadas, E-mail: hadas.katz@monash.edu [Department of Materials Engineering, Monash University, VIC 3800 (Australia); Rossouw, Chris J. [Monash Centre for Electron Microscopy, Monash University, VIC 3800 (Australia); Dwyer, Christian; Etheridge, Joanne [Department of Materials Engineering, Monash University, VIC 3800 (Australia); Monash Centre for Electron Microscopy, Monash University, VIC 3800 (Australia)

    2013-01-15

    A method to measure the thickness of a single-crystal nanoparticle in the direction parallel to the incident beam from annular dark field scanning transmission electron microscope (ADF-STEM) images is reported, providing a map of thickness versus position across the nanoparticle-a 'thickness profile' image. The method is rapid and hence suitable for surveying large numbers of nanoparticles. The method measures the intensity scattered to a characterised ADF detector and compares this to the incident beam intensity, to obtain a normalized ADF image. The normalised intensity is then converted to thickness via dynamical ADF image simulations. The method is accurate within 10% and the precision is dominated primarily by 'shot noise'. Merits and limitations of this method are discussed. A method to calibrate the response function of the ADF detector without external equipment is also described, which is applicable to the entire range of gain and background settings. -- Highlights: Black-Right-Pointing-Pointer A method is developed to convert ADF-STEM images to 'thickness profile' images. Black-Right-Pointing-Pointer It is applicable in particles survey, facets determination and discrete tomography. Black-Right-Pointing-Pointer A method to calibrate the response of the ADF detector is described. Black-Right-Pointing-Pointer The response in analysed across a range of conditions. Black-Right-Pointing-Pointer Dynamical ADF image simulations are presented, demonstrating intensity vs. thickness dependence.

  11. Epicardial Adipose Tissue Thickness in Patients With Subclinical Hypothyroidism and the Relationship Thereof With Visceral Adipose Tissue Thickness.

    Science.gov (United States)

    Arpaci, Dilek; Gurkan Tocoglu, Aysel; Yilmaz, Sabiye; Korkmaz, Sumeyye; Ergenc, Hasan; Gunduz, Huseyin; Keser, Nurgul; Tamer, Ali

    2016-03-01

    Subclinical hypothyroidism (SH) is associated with cardiovascular metabolic syndromes, especially dislipidemia and abdominal obesity. Visceral abdominal adipose tissue (VAAT) and epicardial adipose tissue (EAT) have the same ontogenic origin and produce many proinflammatory and proatherogenic cytokines. We evaluated EAT and VAAT thickness in patients with SH. Forty-one patients with SH and 35 controls were included in the study. Demographical and anthropometric features of both patients and controls were recorded. Thyroid and metabolic parameters were measured. EAT was measured using 2D-transthoracic echocardiography. The age and gender distributions were similar in the two groups (P = 0.998 and P = 0.121, respectively). Body mass index (BMI), fat mass, waist circumference (WC), hip circumference (HC), the WC/HC ratio, and the thicknesses of VAAT and abdominal subcutaneous adipose tissue were higher in the case group than the control group (all P values 0.05). We found no difference between the two groups in fasting plasma glucose (FPG) level (P = 0.780), but the levels of LDL-C and TG differed significantly (P = 0.002 and P = 0.026, respectively). The serum TSH level was higher and the FT4 level was lower in the case than the control group (both P values <0.01). Increased abdominal adipose tissue thickness in patients with SH is associated with atherosclerosis. To detemine the risk of atherosclerosis in such patients, EAT measurements are valuable; such assessment is simple to perform.

  12. Renal parenchyma thickness: a rapid estimation of renal function on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kaplon, Daniel M.; Lasser, Michael S.; Sigman, Mark; Haleblian, George E.; Pareek, Gyan [The Warren Alpert School of Medicine of Brown University, Providence, RI (United States). Dept. pf Surgery. Section of Minimally Invasive Urologic Surgery], e-mail: kaplonda@gmail.com

    2009-01-15

    Purpose: To define the relationship between renal parenchyma thickness (RPT) on computed tomography and renal function on nuclear renography in chronically obstructed renal units (ORUs) and to define a minimal thickness ratio associated with adequate function. Materials and Methods: Twenty-eight consecutive patients undergoing both nuclear renography and CT during a six-month period between 2004 and 2006 were included. All patients that had a diagnosis of unilateral obstruction were included for analysis. RPT was measured in the following manner: The parenchyma thickness at three discrete levels of each kidney was measured using calipers on a CT workstation. The mean of these three measurements was defined as RPT. The renal parenchyma thickness ratio of the ORUs and non-obstructed renal unit (NORUs) was calculated and this was compared to the observed function on Mag-3 lasix Renogram. Results: A total of 28 patients were evaluated. Mean parenchyma thickness was 1.82 cm and 2.25 cm in the ORUs and NORUs, respectively. The mean relative renal function of ORUs was 39%. Linear regression analysis comparing renogram function to RPT ratio revealed a correlation coefficient of 0.48 (p < 0.001). The linear regression equation was computed as Renal Function = 0.48 + 0.80{sup *} RPT ratio. A thickness ratio of 0.68 correlated with 20% renal function. Conclusion: RPT on computed tomography appears to be a powerful predictor of relative renal function in ORUs. Assessment of RPT is a useful and readily available clinical tool for surgical decision making (renal salvage therapy versus nephrectomy) in patients with ORUs. (author)

  13. Renal parenchyma thickness: a rapid estimation of renal function on computed tomography

    Directory of Open Access Journals (Sweden)

    Daniel M. Kaplon

    2009-02-01

    Full Text Available Purpose: To define the relationship between renal parenchyma thickness (RPT on computed tomography and renal function on nuclear renography in chronically obstructed renal units (ORUs and to define a minimal thickness ratio associated with adequate function. Materials and Methods: Twenty-eight consecutive patients undergoing both nuclear renography and CT during a six-month period between 2004 and 2006 were included. All patients that had a diagnosis of unilateral obstruction were included for analysis. RPT was measured in the following manner: The parenchyma thickness at three discrete levels of each kidney was measured using calipers on a CT workstation. The mean of these three measurements was defined as RPT. The renal parenchyma thickness ratio of the ORUs and non-obstructed renal unit (NORUs was calculated and this was compared to the observed function on Mag-3 lasix Renogram. Results: A total of 28 patients were evaluated. Mean parenchyma thickness was 1.82 cm and 2.25 cm in the ORUs and NORUs, respectively. The mean relative renal function of ORUs was 39%. Linear regression analysis comparing renogram function to RPT ratio revealed a correlation coefficient of 0.48 (p < 0.001. The linear regression equation was computed as Renal Function = 0.48 + 0.80 * RPT ratio. A thickness ratio of 0.68 correlated with 20% renal function. Conclusion: RPT on computed tomography appears to be a powerful predictor of relative renal function in ORUs. Assessment of RPT is a useful and readily available clinical tool for surgical decision making (renal salvage therapy versus nephrectomy in patients with ORUs.

  14. Study on the Clinical Significance of Mathematical Relations between the Thickness of Facial Soft Tissues in Male

    Institute of Scientific and Technical Information of China (English)

    WANG Zixuan; WANG Qinghua

    2002-01-01

    Objective To discuss the mathematical relations between the thickness of facial soft tissues. Mehtods Measured the thickness of facial soft tissue on X- ray film (51 men). Record seven data every man, computed their related ratio and analysis all the data with SPSS software. Result All of the items were positive correlation and their correlations were significant expect the correlation between the thickness of hair line point and the Sn point. All the results were normal distribution. Conclusion The results can be used to calculate the thickness of injured facial soft tissue in male.

  15. Rifting Thick Lithosphere - Canning Basin, Western Australia

    Science.gov (United States)

    Czarnota, Karol; White, Nicky

    2016-04-01

    The subsidence histories and architecture of most, but not all, rift basins are elegantly explained by extension of ~120 km thick lithosphere followed by thermal re-thickening of the lithospheric mantle to its pre-rift thickness. Although this well-established model underpins most basin analysis, it is unclear whether the model explains the subsidence of rift basins developed over substantially thick lithosphere (as imaged by seismic tomography beneath substantial portions of the continents). The Canning Basin of Western Australia is an example where a rift basin putatively overlies lithosphere ≥180 km thick, imaged using shear wave tomography. Subsidence modelling in this study shows that the entire subsidence history of the Canning Basin is adequately explained by mild Ordovician extension (β≈1.2) of ~120 km thick lithosphere followed by post-rift thermal subsidence. This is consistent with the established model, described above, albeit with perturbations due to transient dynamic topography support which are expressed as basin-wide unconformities. In contrast the Canning Basin reveals an almost continuous period of normal faulting between the Ordovician and Carboniferous (βCanning Basin to rifting of thick lithosphere beneath the eastern part, verified by the presence of ~20 Ma diamond-bearing lamproites intruded into the basin depocentre. In order to account for the observed subsidence, at standard crustal densities, the lithospheric mantle is required to be depleted in density by 50-70 kg m-3, which is in line with estimates derived from modelling rare-earth element concentrations of the ~20 Ma lamproites and global isostatic considerations. Together, these results suggest that thick lithosphere thinned to > 120 km is thermally stable and is not accompanied by post-rift thermal subsidence driven by thermal re-thickening of the lithospheric mantle. Our results show that variations in lithospheric thickness place a fundamental control on basin architecture

  16. Sampling supraglacial debris thickness using terrestrial photogrammetry

    Science.gov (United States)

    Nicholson, Lindsey; Mertes, Jordan

    2017-04-01

    The melt rate of debris-covered ice differs to that of clean ice primarily as a function of debris thickness. The spatial distribution of supraglacial debris thickness must therefore be known in order to understand how it is likely to impact glacier behaviour, and meltwater contribution to local hydrological resources and global sea level rise. However, practical means of determining debris cover thickness remain elusive. In this study we explore the utility of terrestrial photogrammetry to produce high resolution, scaled and texturized digital terrain models of debris cover exposures above ice cliffs as a means of quantifying and characterizing debris thickness. Two Nikon D5000 DSLRs with Tamron 100mm lenses were used to photograph a sample area of the Ngozumpa glacier in the Khumbu Himal of Nepal in April 2016. A Structure from Motion workflow using Agisoft Photoscan software was used to generate a surface models with debris thickness along the exposed cliffline were made from this scaled model, assuming that the ice surface at the debris-ice boundary is horizontal, and these data are compared to 50 manual point measurements along the same clifftops. We conclude that sufficiently high resolution photogrammetry, with precise scaling information, provides a useful means to determine debris thickness at clifftop exposures. The resolution of the possible measurements depends on image resolution, the accuracy of the ground control points and the computational capacity to generate centimetre scale surface models. Application of such techniques to sufficiently high resolution imagery from UAV-borne cameras may offer a powerful means of determining debris thickness distribution patterns over debris covered glacier termini.

  17. Deriving aerosol scattering ratio using range-resolved lidar ratio

    Indian Academy of Sciences (India)

    Reji K Dhaman; V Krishnakumar; V P Mahadevan Pillai; M Satyanarayana; K Raghunath

    2014-02-01

    The study on the optical characteristics of aerosol is carried out using the dual polarization lidar observations from the tropical inland station Gadanki (13.5°N, 79.2°E) for the period of observation during the year 2010. The summer and monsoon observation days show high scattering ratio at the tropical tropopause layer (TTL) and at the lower stratosphere region. The depolarization ratio is also high at this altitude due to the transport of particulates to the TTL layer by the active convection prevailing at the period. The study reveals more dependable values of scattering ratio that are seasonal and range-dependent.

  18. Holes at High Blowing Ratios

    Directory of Open Access Journals (Sweden)

    Phillip M. Ligrani

    1996-01-01

    Full Text Available Experimental results are presented which describe the development and structure of flow downstream of a single row of holes with compound angle orientations producing film cooling at high blowing ratios. This film cooling configuration is important because similar arrangements are frequently employed on the first stage of rotating blades of operating gas turbine engines. With this configuration, holes are spaced 6d apart in the spanwise direction, with inclination angles of 24 degrees, and angles of orientation of 50.5 degrees. Blowing ratios range from 1.5 to 4.0 and the ratio of injectant to freestream density is near 1.0. Results show that spanwise averaged adiabatic effectiveness, spanwise-averaged iso-energetic Stanton number ratios, surveys of streamwise mean velocity, and surveys of injectant distributions change by important amounts as the blowing ratio increases. This is due to injectant lift-off from the test surface just downstream of the holes.

  19. High-performance metasurface polarizers with extinction ratios exceeding 12000.

    Science.gov (United States)

    Kurosawa, Hiroyuki; Choi, Bongseok; Sugimoto, Yoshimasa; Iwanaga, Masanobu

    2017-02-20

    High-performance ultrathin polarizers have been experimentally demonstrated employing stacked complementary (SC) metasurfaces, which were produced using nanoimprint lithography. It is experimentally determined that the metasurface polarizers composed of Ag and Au have large extinction ratios exceeding 17000 and 12000, respectively, in spite of the subwavelength thickness. It is also shown that the ultrathin polarizers of the SC structures are optimized at telecommunication wavelengths.

  20. Controlling metamaterial resonances via dielectric and aspect ratio effects

    CERN Document Server

    Chiam, Sher-Yi; Zhang, Weili; Bettiol, Andrew A

    2010-01-01

    We study ways to enhance the sensitivity and dynamic tuning range of the fundamental inductor-capacitor (LC) resonance in split ring resonators (SRRs) by controlling the aspect ratio of the SRRs and their substrate thickness. We conclude that both factors can significantly affect the LC resonance. We show that metafilms consisting of low height SRRs on a thin substrate are most sensitive to changes in their dielectric environment and thus show excellent potential for sensing applications.

  1. The effect of resistance exercise direction for hip joint stabilization on lateral abdominal muscle thickness

    Science.gov (United States)

    Jung, Ju-Hyeon; Lee, Sang-Yeol

    2016-01-01

    The aim of this study was to determine the effects of resistance direction in hip joint stabilization exercise on change in lateral abdominal muscle thickness in healthy adults. Twenty-six healthy adults were randomly allocated to either a hip stabilization exercise by hip straight resistance group (n=12) or a hip diagonal resistance group (n=14). The outcome measures included contraction thickness ratio in transversus abdominis (TrA), internal oblique (IO) and external oblique, and TrA lateral slide were assessed during the abdominal drawing-in maneuver by b-mode ultrasound. The researcher measured the abdominal muscle thickness of each participant before the therapist began the intervention and at the moment intervention was applied. There was a significant difference in lateral abdominal muscle thickness between the straight resistance exercise of hip joint group and the diagonal resistance exercise of hip joint group. Significant differences were found between the two groups in the percentage of change of muscle thickness of the TrA (P=0.018) and in the thickness ratio of the TrA (P=0.018). Stability exercise accompanied by diagonal resistance on the hip joint that was applied in this study can induce automatic contraction of the IO and TrA, which provides stability to the lumbar spine. PMID:27807520

  2. Snow thickness retrieval over thick Arctic sea ice using SMOS satellite data

    Directory of Open Access Journals (Sweden)

    N. Maaß

    2013-12-01

    Full Text Available The microwave interferometric radiometer of the European Space Agency's Soil Moisture and Ocean Salinity (SMOS mission measures at a frequency of 1.4 GHz in the L-band. In contrast to other microwave satellites, low frequency measurements in L-band have a large penetration depth in sea ice and thus contain information on the ice thickness. Previous ice thickness retrievals have neglected a snow layer on top of the ice. Here, we implement a snow layer in our emission model and investigate how snow influences L-band brightness temperatures and whether it is possible to retrieve snow thickness over thick Arctic sea ice from SMOS data. We find that the brightness temperatures above snow-covered sea ice are higher than above bare sea ice and that horizontal polarisation is more affected by the snow layer than vertical polarisation. In accordance with our theoretical investigations, the root mean square deviation between simulated and observed horizontally polarised brightness temperatures decreases from 20.9 K to 4.7 K, when we include the snow layer in the simulations. Although dry snow is almost transparent in L-band, we find brightness temperatures to increase with increasing snow thickness under cold Arctic conditions. The brightness temperatures' dependence on snow thickness can be explained by the thermal insulation of snow and its dependence on the snow layer thickness. This temperature effect allows us to retrieve snow thickness over thick sea ice. For the best simulation scenario and snow thicknesses up to 35 cm, the average snow thickness retrieved from horizontally polarised SMOS brightness temperatures agrees within 0.1 cm with the average snow thickness measured during the IceBridge flight campaign in the Arctic in spring 2012. The corresponding root mean square deviation is 5.5 cm, and the coefficient of determination is r2 = 0.58.

  3. Snow thickness retrieval over thick Arctic sea ice using SMOS satellite data

    Directory of Open Access Journals (Sweden)

    N. Maaß

    2013-07-01

    Full Text Available The microwave interferometric radiometer of the European Space Agency's Soil Moisture and Ocean Salinity (SMOS mission measures at a frequency of 1.4 GHz in the L-band. In contrast to other microwave satellites, low frequency measurements in L-band have a large penetration depth in sea ice and thus contain information on the ice thickness. Previous ice thickness retrievals have neglected a snow layer on top of the ice. Here, we implement a snow layer in our emission model and investigate how snow influences L-band brightness temperatures and whether it is possible to retrieve snow thickness over thick Arctic sea ice from SMOS data. We find that the brightness temperatures above snow-covered sea ice are higher than above bare sea ice and that horizontal polarisation is more affected by the snow layer than vertical polarisation. In accordance with our theoretical investigations, the root mean square deviation between simulated and observed horizontally polarised brightness temperatures decreases from 20.0 K to 4.4 K, when we include the snow layer in the simulations. Under cold Arctic conditions we find brightness temperatures to increase with increasing snow thickness. Because dry snow is almost transparent in L-band, this brightness temperature's dependence on snow thickness origins from the thermal insulation of snow and its dependence on the snow layer thickness. This temperature effect allows us to retrieve snow thickness over thick sea ice. For the best simulation scenario and snow thicknesses up to 35 cm, the average snow thickness retrieved from horizontally polarised SMOS brightness temperatures agrees within 0.7 cm with the average snow thickness measured during the IceBridge flight campaign in the Arctic in spring 2012. The corresponding root mean square deviation is 6.3 cm, and the correlation coefficient is r2 = 0.55.

  4. The effect of nicotine on choroidal thickness.

    Science.gov (United States)

    Zengin, Mehmet Ozgur; Cinar, Esat; Kucukerdonmez, Cem

    2014-02-01

    To investigate the effect of nicotine on choroidal thickness using optical coherence tomography (OCT). Prospective, case-control study. Sixteen young, healthy subjects and 16 age and gender matched control cases were included in this study; 4 mg nicotine gum was given to the study group and placebo gum to the control group. All participants underwent OCT scanning with a high-speed and resolution spectral-domain OCT device (3D OCT 2000, Topcon, Japan) at baseline, and 1 h following nicotine or placebo administration. The measurements were taken in the morning (10:00-12:00 hours) to avoid diurnal fluctuation. The median foveal choroidal thickness at baseline was 337.00 μm (IQR 84.50), which decreased to 311.00 μm (IQR 78.00) at 1 h following oral nicotine intake (p=0.001). The median choroidal thickness was also significantly decreased at five other extrafoveal points (pchoroidal thickness at the fovea was 330.50 μm (IQR 104.25), and was 332.00 μm (IQR 103.75) at 1 h (p=0.271). Nicotine causes a significant decrease in choroidal thickness following oral intake. This acute decrease might be a result of reduced ocular blood flow due to the vasoconstrictive effect of nicotine.

  5. Prospective trial of thick vs standard split-thickness skin grafts in burns of the hand.

    Science.gov (United States)

    Mann, R; Gibran, N S; Engrav, L H; Foster, K N; Meyer, N A; Honari, S; Costa, B A; Heimbach, D M

    2001-01-01

    For best function and appearance, thick skin grafts for hands are generally preferred to thinner grafts. But how thick is thick enough? This prospective randomized trial was designed to compare 0.015-inch skin grafts for burned hands to hand grafts that are 0.025 inches thick. Consecutive patients receiving skin grafts to hands were randomized to have sheet grafts using donor sites of 0.015-inch or 0.025-inch thickness. To prevent delayed healing and potential hypertrophic scarring, the thick graft donor sites were grafted with 0.008-inch grafts. There were no significant differences in range of motion, final appearance, or patient satisfaction between the two groups at 1 year. There were problems with donor site healing in both groups. We recommend that hand grafts for adults be at least 0.015 inches thick but do not see an advantage to the use of very thick (0.025-inch) grafts, even with thin split-thickness skin grafts to the donor site.

  6. Study on Folds of Equal Thickness Multi-layer Sandwiched in Different Thickness Media

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The theoretical model and non-homogeneous differential equation of equal thickness multi-layer folds sandwiched in different thickness and same character media are established by elastic and plastic mechanics. The special answer of the non-homogeneous differential equation and the common answer of the homogeneous differential equation are deduced by applying logistic equation and special function, and the dominant wavelength theory of equal thickness multi-layer folds sandwiched in different thickness and same character media. In addition, the experimental folding in both elastic and sticky materials proves the dominant wavelength theory.

  7. Poisson's Ratio and Young's Modulus of Lipid Bilayers in Different Phases

    NARCIS (Netherlands)

    Jadidi, T.; Seyyed-Allaei, H.; Reza Tahimi Tabar, M.; Mashaghi, A.

    2014-01-01

    A general computational method is introduced to estimate the Poisson’s ratio for membranes with small thickness. In this method, the Poisson’s ratio is calculated by utilizing a rescaling of inter-particle distances in one lateral direction under periodic boundary conditions. As an example for the c

  8. Study of refractive index and thickness of TiO2/ormosil planar waveguide

    Institute of Scientific and Technical Information of China (English)

    Wang Bao-Ling; Hu Li-Li

    2004-01-01

    Hybrid titania/ormosil waveguide films have been prepared by sol-gel method at low thermal treatment temperature of 150℃. The influence of processing parameters including the molar ratios of Ti(OBu)4/ glycidoxypropyltrimethoxysilane (GLYMO) and H2O/Ti(OBu)4 (expressed as R), especially aging of sol, on the refractive index and thickness of film was investigated. The optical properties of films were measured with Scanning Electron Microscope and m-line spectroscopy. The results indicate that the film thickness increases with the aging time of sol, but the variation of refractive index as a function of aging time of sol depends on the relative ratio of GLYMO to Ti-alkoxide.The relation between film thickness and corresponding sol viscosity is linear as the volume of GLYMO is 80% within the range of measured data.

  9. Antarctic Crustal Thickness from Gravity Inversion

    Science.gov (United States)

    Vaughan, A. P.; Kusznir, N. J.; Ferraccioli, F.; Jordan, T. A.

    2013-12-01

    Using gravity anomaly inversion, we have produced the first comprehensive regional maps of crustal thickness and oceanic lithosphere distribution for Antarctica and the Southern Ocean. We determine Moho depth, crustal basement thickness, continental lithosphere thinning (1-1/β) and ocean-continent transition location using a 3D spectral domain gravity inversion method, which incorporates a lithosphere thermal gravity anomaly correction. The continental lithosphere thinning distribution, used to define the initial thermal model temperature perturbation is derived from the gravity inversion and uses no a priori isochron information; as a consequence the gravity inversion method provides a prediction of ocean-continent transition location, which is independent of ocean isochron information. The gravity anomaly contribution from ice thickness is included in the gravity inversion, as is the contribution from sediments which assumes a compaction controlled sediment density increase with depth. Data used in the gravity inversion are elevation and bathymetry, free-air gravity anomaly, the most recent Bedmap2 ice thickness and bedrock topography compilation south of 60 degrees south (Fretwell et al., 2013) and relatively sparse constraints on sediment thickness. Our gravity inversion study predicts thick crust (> 45 km) under interior East Antarctica penetrated by narrow continental rifts that feature relatively thinner crust. The East Antarctic Rift System (EARS) is a major Permian to Cretaceous age rift system that appears to extend from the continental margin at the Lambert Rift to the South Pole region, a distance of 2500 km. This is comparable in scale to the well-studied East African rift system. Intermediate crustal thickness with an inferred linear rift fabric is predicted under Coates Land. An extensive region of either thick oceanic crust or highly thinned continental crust is predicted offshore Oates Land and north Victoria Land, and also off West Antarctica

  10. Residual Stress Analysis in Thick Uranium Films

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, A M; Foreman, R J; Gallegos, G F

    2004-12-06

    Residual stress analysis was performed on thick, 1.0 to 25 {micro}m, depleted Uranium (DU) films deposited on an Al substrate by magnetron sputtering. Two distinct characterization techniques were used to measure substrate curvature before and after deposition. Stress evaluation was performed using the Benabdi/Roche equation, which is based on beam theory of a bi-layer material. The residual stress evolution was studied as a function of coating thickness and applied negative bias voltage (0-300V). The stresses developed were always compressive; however, increasing the coating thickness and applying a bias voltage presented a trend towards more tensile stresses and thus an overall reduction of residual stresses.

  11. Theory of the sea ice thickness distribution

    CERN Document Server

    Toppaladoddi, Srikanth

    2015-01-01

    We use concepts from statistical physics to transform the original evolution equation for the sea ice thickness distribution $g(h)$ due to Thorndike et al., (1975) into a Fokker-Planck like conservation law. The steady solution is $g(h) = {\\cal N}(q) h^q \\mathrm{e}^{-~ h/H}$, where $q$ and $H$ are expressible in terms of moments over the transition probabilities between thickness categories. The solution exhibits the functional form used in observational fits and shows that for $h \\ll 1$, $g(h)$ is controlled by both thermodynamics and mechanics, whereas for $h \\gg 1$ only mechanics controls $g(h)$. Finally, we derive the underlying Langevin equation governing the dynamics of the ice thickness $h$, from which we predict the observed $g(h)$. The genericity of our approach provides a framework for studying the geophysical scale structure of the ice pack using methods of broad relevance in statistical mechanics.

  12. Black hole feedback from thick accretion discs

    CERN Document Server

    Sadowski, Aleksander; Abramowicz, Marek A; Narayan, Ramesh

    2015-01-01

    We study energy flows in geometrically thick accretion discs, both optically thick and thin, using general relativistic, three-dimensional simulations of black hole accretion flows. We find that for non-rotating black holes the efficiency of the total feedback from thick accretion discs is $3\\%$ - roughly half of the thin disc efficiency. This amount of energy is ultimately distributed between outflow and radiation, the latter scaling weakly with the accretion rate for super-critical accretion rates, and returned to the interstellar medium. Accretion on to rotating black holes is more efficient because of the additional extraction of rotational energy. However, the jet component is collimated and likely to interact only weakly with the environment, whereas the outflow and radiation components cover a wide solid angle.

  13. Thickness diffusivity in the Southern Ocean

    Science.gov (United States)

    Eden, Carsten

    2006-06-01

    Thickness diffusivity ($\\kappa$) according to the Gent and McWilliams parameterisation which accounts for eddy-driven advection in the ocean, is estimated using output from an eddy-resolving model of the Southern Ocean. A physically meaningful definition of rotational eddy fluxes leads almost everywhere to positive $\\kappa$. Zonally averaged near surface values of $\\kappa$ remain smaller than 200 m2/s poleward of the polar front, increases between 60-45°S to about 600 m2/s and peak between 45-35° S at almost 3000 m2/s. $\\kappa$ stays high in the upper 500 m but decreases with depth and is essentially zero below 2500 m. In addition to the thickness diffusion ($\\kappa$) there is eddy-induced eastward (westward) advection of isopycnal thickness at the poleward (equatorward) flank of the ACC pointing toward strong anisotropic lateral mixing.

  14. Partial Thickness Rotator Cuff Tears: Current Concepts

    Science.gov (United States)

    Matthewson, Graeme; Beach, Cara J.; Nelson, Atiba A.; Woodmass, Jarret M.; Ono, Yohei; Boorman, Richard S.; Lo, Ian K. Y.; Thornton, Gail M.

    2015-01-01

    Partial thickness rotator cuff tears are a common cause of pain in the adult shoulder. Despite their high prevalence, the diagnosis and treatment of partial thickness rotator cuff tears remains controversial. While recent studies have helped to elucidate the anatomy and natural history of disease progression, the optimal treatment, both nonoperative and operative, is unclear. Although the advent of arthroscopy has improved the accuracy of the diagnosis of partial thickness rotator cuff tears, the number of surgical techniques used to repair these tears has also increased. While multiple repair techniques have been described, there is currently no significant clinical evidence supporting more complex surgical techniques over standard rotator cuff repair. Further research is required to determine the clinical indications for surgical and nonsurgical management, when formal rotator cuff repair is specifically indicated and when biologic adjunctive therapy may be utilized. PMID:26171251

  15. High-capacity thick cathode with a porous aluminum current collector for lithium secondary batteries

    Science.gov (United States)

    Abe, Hidetoshi; Kubota, Masaaki; Nemoto, Miyu; Masuda, Yosuke; Tanaka, Yuichi; Munakata, Hirokazu; Kanamura, Kiyoshi

    2016-12-01

    A high-capacity thick cathode has been studied as one of ways to improve the energy density of lithium secondary batteries. In this study, the LiFePO4 cathode with a capacity per unit area of 8.4 m Ah cm-2 corresponding to four times the capacity of conventional cathodes has been developed using a three-dimensional porous aluminum current collector called "FUSPOROUS". This unique current collector enables the smooth transfer of electrons and Li+-ions through the thick cathode, resulting in a good rate capability (discharge capacity ratio of 1.0 C/0.2 C = 0.980) and a high charge-discharge cycle performance (80% of the initial capacity at 2000th cycle) even though the electrode thickness is 400 μm. To take practical advantage of the developed thick cathode, conceptual designs for a 10-Ah class cell were also carried out using graphite and lithium-metal anodes.

  16. Finite thickness lens model for self-focusing (defocusing) in Kerr medium

    Institute of Scientific and Technical Information of China (English)

    Shi-fang GUO; Qiang TIAN

    2009-01-01

    A "finite thickness lens" model for self-focusing (defocusing) in Kerr medium is presented. An onaxis normalization transmittance formula is presented for arbitrary nonlinear phase shift for the finite thickness Kerr medium by introducing a nonlinear ABCD-matrix for the transition of a Gaussian beam from linear to nonlinear medium, without complex calculation for the beam radius at the far field aperture. The variation of the peak and valley transmittance difference is found to enhance linearly as the phase shift at the focus increases by increasing the thickness of the medium. If the ratio of the Rayleigh distance divided by the thickness of the medium (d/zo) is constant and small enough, the peak and valley transmittance difference stays constant. Finally, a qualitative formula is presented to express the relationship between the system parameters and the on-axis phase shift at the focus.

  17. Endometrial thickness predicts endometrial hyperplasia in patients with polycystic ovary syndrome.

    Science.gov (United States)

    McCormick, Betsy A; Wilburn, Rochelle D; Thomas, Michael A; Williams, Daniel B; Maxwell, Rose; Aubuchon, Mira

    2011-06-30

    Body mass index is predictive of sonographic endometrial stripe thickness, which in turn is predictive of endometrial hyperplasia in patients with polycystic ovary syndrome. For every 1-mm increase in endometrial stripe, the odds ratio of hyperplasia increased by 1.48 (95% confidence interval, 1.04-2.10).

  18. Design and Experimental Validation of Thick Airfoils for Large Wind Turbines

    DEFF Research Database (Denmark)

    Hrgovan, Iva; Shen, Wen Zhong; Zhu, Wei Jun

    2015-01-01

    In this chapter, two new airfoils with thickness to chord ratios of 30 and 36 % are presented, which were designed with an objective of good aerodynamic and structural features. Airfoil design is based on a direct method using shape perturbation function. The optimization algorithm is coupled wit...

  19. Hot rolling of thick uranium molybdenum alloys

    Science.gov (United States)

    DeMint, Amy L.; Gooch, Jack G.

    2015-11-17

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

  20. Crustal thickness controlled by plate tectonics

    DEFF Research Database (Denmark)

    Artemieva, Irina M.; Meissner, Rolf

    2012-01-01

    /gabbro–eclogite phase transition in crustal evolution and the links between lithosphere recycling, mafic magmatism, and crustal underplating. We advocate that plate tectonics processes, togetherwith basalt/gabbro–eclogite transition, limit crustal thickness worldwide by providing effective mechanisms of crustal...... (lithosphere) recycling. The processes of crust–mantle interaction have created very dissimilar crustal styles in Europe, as seen by its seismic structure, crustal thickness, and average seismic velocities in the basement. Our special focus is on processes responsible for the formation of the thin crust...

  1. Compressive strength of thick composite panels

    DEFF Research Database (Denmark)

    Branner, Kim; Berring, Peter

    2011-01-01

    The aim of this study is to investigate how much the compressive strength of thick composite panels is reduced due to delaminations and to investigate under which conditions a delamination will grow. Understanding of this is essential in order to move forward the design limits used in the structu......The aim of this study is to investigate how much the compressive strength of thick composite panels is reduced due to delaminations and to investigate under which conditions a delamination will grow. Understanding of this is essential in order to move forward the design limits used...

  2. Nuclear symmetry energy and neutron skin thickness

    CERN Document Server

    Warda, M; Viñas, X; Roca-Maza, X

    2012-01-01

    The relation between the slope of the nuclear symmetry energy at saturation density and the neutron skin thickness is investigated. Constraints on the slope of the symmetry energy are deduced from the neutron skin data obtained in experiments with antiprotonic atoms. Two types of neutron skin are distinguished: the "surface" and the "bulk". A combination of both types forms neutron skin in most of nuclei. A prescription to calculate neutron skin thickness and the slope of symmetry energy parameter $L$ from the parity violating asymmetry measured in the PREX experiment is proposed.

  3. Effect of geometry on hydrodynamic film thickness

    Science.gov (United States)

    Brewe, D. E.; Hamrock, B. J.; Taylor, C. M.

    1978-01-01

    The influence of geometry on the isothermal hydrodynamic film separating two rigid solids was investigated. Pressure-viscosity effects were not considered. The minimum film thickness is derived for fully flooded conjunctions by using the Reynolds boundary conditions. It was found that the minimum film thickness had the same speed, viscosity, and load dependence as Kapitza's classical solution. However, the incorporation of Reynolds boundary conditions resulted in an additional geometry effect. Solutions using the parabolic film approximation are compared with those using the exact expression for the film in the analysis. Contour plots are shown that indicate in detail the pressure developed between the solids.

  4. Carbon Monoxide Mixing Ratio System

    Data.gov (United States)

    Oak Ridge National Laboratory — The Southern Great Plains (SGP) Carbon Monoxide (CO) system provides high-precision atmospheric concentration measurements of CO mixing ratio (ppbv dry air) every 10...

  5. Pressure Ratio to Thermal Environments

    Science.gov (United States)

    Lopez, Pedro; Wang, Winston

    2012-01-01

    A pressure ratio to thermal environments (PRatTlE.pl) program is a Perl language code that estimates heating at requested body point locations by scaling the heating at a reference location times a pressure ratio factor. The pressure ratio factor is the ratio of the local pressure at the reference point and the requested point from CFD (computational fluid dynamics) solutions. This innovation provides pressure ratio-based thermal environments in an automated and traceable method. Previously, the pressure ratio methodology was implemented via a Microsoft Excel spreadsheet and macro scripts. PRatTlE is able to calculate heating environments for 150 body points in less than two minutes. PRatTlE is coded in Perl programming language, is command-line-driven, and has been successfully executed on both the HP and Linux platforms. It supports multiple concurrent runs. PRatTlE contains error trapping and input file format verification, which allows clear visibility into the input data structure and intermediate calculations.

  6. Analysis, Design and Implementation of Human Fingerprint Patterns System “Towards Age & Gender Determination, Ridge Thickness To Valley Thickness Ratio (RTVTR & Ridge Count On Gender Detection

    Directory of Open Access Journals (Sweden)

    E O Omidiora

    2012-05-01

    Full Text Available The aim of this research is to analyze humans fingerprint texture in order to determine their Age & Gender, and correlation of RTVTR and Ridge Count on gender detection. The study is to analyze the effectiveness of physical biometrics (thumbprint in order to determine age and gender in humans. An application system was designed to capture the finger prints of sampled population through a fingerprint scanner device interfaced to the computer system via Universal Serial Bus (USB, and stored in Microsoft SQL Server database, while back-propagation neural network will be used to train the stored fingerprint. The specific Objectives of this research are to: Use fingerprint sensor to collect different individual fingerprint, alongside their age and gender, Formulate a model and develop a fingerprint based identification system to determine age and gender of individuals and evaluate the developed system.

  7. Thick Slice and Thin Slice Teaching Evaluations

    Science.gov (United States)

    Tom, Gail; Tong, Stephanie Tom; Hesse, Charles

    2010-01-01

    Student-based teaching evaluations are an integral component to institutions of higher education. Previous work on student-based teaching evaluations suggest that evaluations of instructors based upon "thin slice" 30-s video clips of them in the classroom correlate strongly with their end of the term "thick slice" student evaluations. This study's…

  8. Modeling of thickness for semisolid foods

    NARCIS (Netherlands)

    Terpstra, M.E.J.; Janssen, A.M.; Prinz, J.F.; Wijk, R.A. de; Weenen, H.; Linden, E. van der

    2005-01-01

    We investigated the relationship between orally perceived thickness and calculated shear stress on the tongue for mayonnaise and custard. To this end, the applicability of the models of Kokini et al. (1977), describing the mechanical breakdown in the mouth, have been tested. Within a limited range o

  9. Evaluating choroidal thickness in diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Chan CY

    2014-06-01

    Full Text Available Chee Yee Chan,1 Thanos D Papakostas,2 Demetrios Vavvas2 1Department of Ophthalmology, 2Retina Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USAWe read with interest the article by Unsal et al1 and congratulate them on their work assessing choroidal thickness in patients with diabetic retinopathy. We will like to highlight some factors of relevance.Unsal et al state that their measurement of the choroid was from the outer part of the retinal pigment epithelial layer to the choroidal scleral junction.1 However, their Figure 2 seems to draw the upper border of the choroid at various locations (external limiting membrane, inner/outer segment junction, top of the retinal pigment epithelium.1 An illustrative diagram (Figure 1 for measuring choroidal thickness can be seen in the study reported by Copete et al.2 Recent studies of the thickness of the retinal pigment epithelium–Bruch’s membrane complex in normal individuals ranged from 17.5 μm to 28.2 μm.3 Hence, measurement of choroidal thickness has to be drawn correctly and consistently at the same location (outer part of the retinal pigment epithelium to minimize potential inaccuracies. View original paper by Unsal and colleagues.

  10. Changes of epidermal thickness in vitiligo.

    Science.gov (United States)

    Jung, Soo-Eun; Kang, Hee Young; Lee, Eun-So; Kim, You Chan

    2015-04-01

    The stratum corneum and epidermal pigmentation have protective roles against ultraviolet radiation. Because vitiligo skin lacks melanocytes and has no potential to produce pigment, some studies suggested that the epidermis in vitiligo skin is thicker than in normal skin. However, only a few studies investigated epidermal thickness changes in vitiligo, and some of these had relatively small sample sizes. Thus, this study aimed to compare epidermal thickness between vitiligo skin and adjacent normal-appearing skin in a large cohort. Photos of hematoxylin and eosin–stained slides of vitiligo skin and adjacent normal-appearing skin were taken under a microscope. The thicknesses of the stratum corneum, viable epidermis, and full epidermis were then measured by a computerized image analyzer. A total of 206 patients (412 sections) were included. There were significant differences between vitiligo skin and adjacent normal-appearing skin in the thickness of the stratum corneum (P = 0.009), viable epidermis (P = 0.001), and total epidermis (P = 0.001). An analysis comparing skin biopsied from a sun-exposed area versus a sun-protected area showed that the stratum corneum, viable epidermis, and total epidermis were significantly thicker in vitiligo skin than in normal-appearing skin in sun-exposed areas (P vitiligo skin than in normal-appearing skin, especially on sun-exposed skin, and that this may represent a photoprotective role compensating for absent pigmentation.

  11. The center conjecture for thick spherical buildings

    CERN Document Server

    Ramos-Cuevas, Carlos

    2009-01-01

    We prove that a convex subcomplex of a spherical building of type E7 or E8 is a subbuilding or the group of building automorphisms preserving the subcomplex has a fixed point in it. Together with previous results of Muehlherr-Tits, and Leeb and the author, this completes the proof of Tits' Center Conjecture for thick spherical buildings.

  12. Modeling of thickness for semisolid foods

    NARCIS (Netherlands)

    Terpstra, M.E.J.; Janssen, A.M.; Prinz, J.F.; Wijk, de R.A.; Weenen, H.; Linden, van der E.

    2005-01-01

    We investigated the relationship between orally perceived thickness and calculated shear stress on the tongue for mayonnaise and custard. To this end, the applicability of the models of Kokini et al. (1977), describing the mechanical breakdown in the mouth, have been tested. Within a limited range

  13. The Diversity of Thick Galactic Discs

    CERN Document Server

    Kasparova, Anastasia V; Chilingarian, Igor V; Silchenko, Olga K; Moiseev, Alexey V; Borisov, Svyatoslav B

    2016-01-01

    Although thick stellar discs are detected in nearly all edge-on disc galaxies, their formation scenarios still remain a matter of debate. Due to observational difficulties, there is a lack of information about their stellar populations. Using the Russian 6-m telescope BTA we collected deep spectra of thick discs in three edge-on S0-a disc galaxies located in different environments: NGC4111 in a dense group, NGC4710 in the Virgo cluster, and NGC5422 in a sparse group. We see intermediate age (4-5 Gyr) metal rich ([Fe/H] $\\sim$ -0.2 - 0.0 dex) stellar populations in NGC4111 and NGC4710. On the other hand, NGC5422 does not harbour young stars, its disc is thick and old (10 Gyr), without evidence for a second component, and its $\\alpha$-element abundance suggests a 1.5-2 Gyr long formation epoch implying its formation at high redshift. Our results suggest the diversity of thick disc formation scenarios.

  14. Thick tool steel coatings with laser cladding

    NARCIS (Netherlands)

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

    2007-01-01

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

  15. Thick tool steel coatings with laser cladding

    NARCIS (Netherlands)

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

    2007-01-01

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

  16. Percolation effect in thick film superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Sali, R.; Harsanyi, G. [Technical Univ. of Budapest (Hungary)

    1994-12-31

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

  17. Macular choroidal thickness in unilateral amblyopic children.

    Science.gov (United States)

    Xu, Jinling; Zheng, Jingwei; Yu, Shujuan; Sun, Zuhua; Zheng, Weiwei; Qu, Peng; Chen, Yuanyuan; Chen, Wuhe; Yu, Xinping

    2014-10-14

    To investigate the choroidal thickness (CT) in children with amblyopia through spectral-domain optical coherence tomography (SD-OCT). Thirty-seven children with unilateral amblyopia and 22 children with normal vision participated in the study. Cross-sectional images of the choroid of evaluated eyes were obtained by SD-OCT. The choroidal thickness was measured directly below the fovea and at eight other locations: 1 and 2 mm superior, temporal, inferior, and nasal to the fovea. The researchers compared the choroidal thickness among amblyopic eyes, fellow eyes of children with amblyopia, and the eyes of children with normal vision. Age, sex, refractive error, axial length, and best-corrected visual acuity were also recorded. A paired t-test was used to compare measurements between amblyopic eyes and fellow eyes in patients with amblyopia. A generalized estimating equation (GEE) was used to compare measurements among amblyopic eyes, fellow eyes, and control eyes, adjusting for the possible effects of age, sex, and axial length on CT. The correlation between choroidal thickness and other continuous variables was determined using the Pearson correlation coefficient. The choroidal thickness at the fovea, 1 and 2 mm superior, 1 mm inferior, 1 mm nasal, and 1 mm temporal to the fovea was greater in amblyopic eyes and in fellow eyes of children with amblyopia than in the eyes of children with normal vision. The choroidal thickness at the fovea and 2 mm nasal to the fovea in amblyopic eyes was greater (P = 0.002, P = 0.043) than in the fellow eyes of the children with amblyopia. The subfoveal CT in amblyopic eyes negatively correlated with axial length (r = -0.501, P = 0.002), but did not correlate with spherical equivalent, logMAR visual acuity, or age. In the subfoveal area, the choroid was thicker in amblyopic eyes than in fellow eyes in children with amblyopia. Furthermore, differences were found in the choroidal thickness in both eyes of children with amblyopia compared

  18. 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.

  19. Peripapillary and Macular Choroidal Thickness in Glaucoma

    Directory of Open Access Journals (Sweden)

    Hamid Hosseini

    2014-01-01

    Full Text Available Purpose: To compare choroidal thickness (CT between individuals with and without glaucomatous damage and to explore the association of peripapillary and submacular CT with glaucoma severity using spectral domain optical coherence tomography (SD-OCT. Methods: Ninety-one eyes of 20 normal subjects and 43 glaucoma patients from the UCLA SD-OCT Imaging Study were enrolled. Imaging was performed using Cirrus HDOCT. Choroidal thickness was measured at four predetermined points in the macular and peripapillary regions, and compared between glaucoma and control groups before and after adjusting for potential confounding variables. Results: The average (± standard deviation mean deviation (MD on visual fields was −0.3 (±2.0 dB in controls and −3.5 (±3.5 dB in glaucoma patients. Age, axial length and their interaction were the most significant factors affecting CT on multivariate analysis. Adjusted average CT (corrected for age, axial length, their interaction, gender and lens status however, was not different between glaucoma patients and the control group (P=0.083 except in the temporal parafoveal region (P=0.037; nor was choroidal thickness related to glaucoma severity (r=−0.187, P=0.176 for correlation with MD, r=−0.151, P=0.275 for correlation with average nerve fiber layer thickness. Conclusions: Choroidal thickness of the macular and peripapillary regions is not decreased in glaucoma. Anatomical measurements with SD-OCT do not support the possible influence of the choroid on the pathophysiology of glaucoma.

  20. Nearshore sediment thickness, Fire Island, New York

    Science.gov (United States)

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

    2017-04-03

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

  1. Laser hole drilling in thick polypropylene sheets for alignment sensors

    Science.gov (United States)

    Bergen, D. E.; Chapman, Glenn H.; Samra, Taranjit S.; Weeks, T. S.

    1996-04-01

    Laser micromachining of polypropylene for transducer applications has the advantage of creating small ( 400 micron). Normally translucent polypropylene formed using carbon as a dye is an excellent laser machining material having a high optical absorption, and a low thermal conductivity. For an optical alignment system a matrix of high aspect ratio holes of 400 micron) sheets. This alignment sensor is to be used on the end of a robot arm and will aid in the manipulation of the arm. Using an argon ion laser focused through a 50 mm lens (5.2 micron R1/e2 spot, 55.2 micron focal depth), holes as small as 30 microns on 150 micron spacing were achieved in 400 - 500 micron thick black polypropylene sheets with consistent results. Best results currently are achieved with a laser power of only 0.3 W, using 10 - 100 pulse stream of 10 - 100 microsec pulses, and duty cycles of polypropylene required 17 times the power, and achieved holes of only 127 microns, with 500 microns spacing in 500 micron thick material. Thicker (1 mm) black polypropylene produces 144 micron holes on 500 micron spacings due to the lip material, and required a 100 mm lens.

  2. Second harmonic generation imaging of fascia within thick tissue block

    Science.gov (United States)

    Pfeffer, Christian P.; Olsen, Bjorn R.; Légaré, François

    2007-06-01

    Comparing the SHG image formation for thin sections of tail tendon fascia and skeletal muscle fascia, we demonstrate that the forward (F) and backward (B) SHG images are vastly different. In addition, despite the different arrangement of the collagen Type I fibrillar architecture forming these two fascias, their ratios of forward over backward signal (F/B) are nearly equal. SHG images of thick tissue blocks of the fascia-muscle unit show only backward features, as opposed to SHG images of tissue blocks of the fascia-tendon unit. These images are an amalgamation of forward and backward features due to the backscattering of forward components within tendon. These forward features disappear when this tissue block is immersed in glycerol as backscattering is hereby suppressed.

  3. Clad thickness variation N-Reactor fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Smith, E.A.

    1966-05-12

    The current specifications for the cladding on {open_quotes}N{close_quotes} fuels were established early in the course of process development and were predicted on several basic considerations. Among these were: (a) a desire to provide an adequate safety factor in cladding thickness to insure against corrosion penetration and rupture from uranium swelling stresses; (b) an apprehension that the striations in the zircaloy cladding of the U/zircaloy interface and on the exterior surface might serve as stress-raisers, leading to untimely failures of the jacket; and (c) then existing process capability - the need to maintain a specified ratio between zircaloy and uranium in the billet assembly to effect satisfactory coextrusion. It now appears appropriate to review these specifications in an effort to determine whether some of them may be revised, with attendant gains in economy and/or operating smoothness.

  4. Development of metal oxide impregnated stilbite thick film ethanol sensor

    Energy Technology Data Exchange (ETDEWEB)

    Mahabole, M. P., E-mail: kashinath.bogle@gmail.com; Lakhane, M. A.; Choudhari, A. L.; Khairnar, R. S. [School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded - 431606 (India)

    2016-05-06

    This paper presents the study of the sensing efficiency of Titanium oxide/ Stilbite and Copper oxide /Stilbite composites towards detection of hazardous pollutants like ethanol. Stilbite based composites are prepared by physically mixing zeolite with metal oxides namely TiO{sub 2} and CuO with weight ratios of 25:75, 50:50 and 75:25. The resulting sensor materials are characterized by X-ray diffraction and Fourier Transform Infrared Spectroscopy techniques. Composite sensors are fabricated in the form of thick film by using screen printing technique. The effect of metal oxide concentration on various ethanol sensing parameters such as operating temperature, maximum uptake capacity and response/recovery time are investigated. The results indicate that metal oxide impregnated stilbite composites have great potential as low temperature ethanol sensor.

  5. Shunting ratios for MHD flows

    Energy Technology Data Exchange (ETDEWEB)

    Birzvalk, Yu.

    1978-01-01

    The shunting ratio and the local shunting ratio, pertaining to currents induced by a magnetic field in a flow channel, are properly defined and systematically reviewed on the basis of the Lagrange criterion. Their definition is based on the energy balance and related to dimensionless parameters characterizing an MHD flow, these parameters evolving from the Hartmann number and the hydrodynamic Reynolds number as well as the magnetic Reynolds number, and the Lundquist number. These shunting ratios, of current density in the core of a stream (uniform) or equivalent mean current density to the short-circuit (maximum) current density, are given here for a slot channel with nonconducting or conducting walls, for a conduction channel with heavy side rails, and for an MHD-flow around bodies. 5 references, 1 figure.

  6. Incentive Ratios of Fisher Markets

    DEFF Research Database (Denmark)

    Chen, Ning; Deng, Xuaitue; Zhang, Hongyang

    2012-01-01

    In a Fisher market, a market maker sells m items to n potential buyers. The buyers submit their utility functions and money endowments to the market maker, who, upon receiving submitted information, derives market equilibrium prices and allocations of its items. While agents may benefit...... by misreporting their private information, we show that the percentage of improvement by a unilateral strategic play, called incentive ratio, is rather limited—it is less than 2 for linear markets and at most $e^{1/e}\\thickapprox 1.445$ for Cobb-Douglas markets. We further prove that both ratios are tight....

  7. Ratio Bias and Policy Preferences

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Tue

    2016-01-01

    Numbers permeate modern political communication. While current scholarship on framing effects has focused on the persuasive effects of words and arguments, this article shows that framing of numbers can also substantially affect policy preferences. Such effects are caused by ratio bias, which...... is a general tendency to focus on numerators and pay insufficient attention to denominators in ratios. Using a population-based survey experiment, I demonstrate how differently framed but logically equivalent representations of the exact same numerical value can have large effects on citizens’ preferences...

  8. ELECTRICALLY FORCED THICKNESS-SHEAR VIBRATIONS OF QUARTZ PLATE WITH NONLINEAR COUPLING TO EXTENSION

    Institute of Scientific and Technical Information of China (English)

    Rongxing Wu; Jiashi Yang; Jianke Du; Ji Wang

    2008-01-01

    We study electrically forced nonlinear thickness-shear vibrations of a quartz plate resonator with relatively large amplitude. It is shown that thickness-shear is nonlinearly coupled to extension due to the well-known Poynting effect in nonlinear elasticity. This coupling is relatively strong when the resonant frequency of the extensional mode is about twice the resonant frequency of the thickness-shear mode. This happens when the plate length/thickness ratio assumes certain values. With this nonlinear coupling, the thickness-shear motion is no longer sinusoidal. Coupling to extension also affects energy trapping which is related to device mounting. When damping is 0.01, nonlinear coupling causes a frequency shift of the order of 10-e which is not insignificant,and an amplitude change of the order of 10-8. The effects are expected to be stronger under real damping of 10-5 or larger. To avoid nonlinear coupling to extension, certain values of the aspect ratio of the plate should be avoided.

  9. The heterogeneous ice shell thickness of Enceladus

    Science.gov (United States)

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

    2016-10-01

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

  10. Ratio Bias and Policy Preferences

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Tue

    2016-01-01

    Numbers permeate modern political communication. While current scholarship on framing effects has focused on the persuasive effects of words and arguments, this article shows that framing of numbers can also substantially affect policy preferences. Such effects are caused by ratio bias, which is ...

  11. Gender Ratios for Reading Difficulties

    Science.gov (United States)

    Hawke, Jesse L.; Olson, Richard K.; Willcut, Erik G.; Wadsworth, Sally J.; DeFries, John C.

    2009-01-01

    The prevalence of reading difficulties is typically higher in males than females in both referred and research-identified samples, and the ratio of males to females is greater in more affected samples. To explore possible gender differences in reading performance, we analysed data from 1133 twin pairs in which at least one member of each pair had…

  12. Charging effects in thick insulating samples

    Energy Technology Data Exchange (ETDEWEB)

    Dias, J.F. E-mail: jfdias@if.ufrgs.br; Bulla, A.; Yoneama, M.-L

    2002-04-01

    In this paper we analyse the effects observed in X-ray spectra when thick insulating targets are irradiated with beams of light charged particles. Preliminary results show that the background yield due to charge buildup on mylar is larger for protons than for lithium ions, suggesting that particles with low energy loss tend to generate more background. Residual activity has been observed in several thick samples like resin, quartz and mylar. Two methods for suppressing the background due to charging effects have been studied. The first one was based on the use of a transverse magnetic field. The second one made use of a simple electric lamp of 6 V with its glass bulb removed. While the first method proved to be inefficient, the second one eliminated most of the background due to charge buildup in the sample.

  13. Thick brane solitons breaking $Z_2$ symmetry

    CERN Document Server

    Peyravi, Marzieh; Lobo, Francisco S N

    2015-01-01

    New soliton solutions for thick branes in 4 + 1 dimensions are considered in this article. In particular, brane models based on the sine-Gordon (SG), $\\varphi^{4}$ and $\\varphi^{6}$ scalar fields are investigated; in some cases $Z_{2}$ symmetry is broken. Besides, these soliton solutions are responsible for supporting and stabilizing the thick branes. In these models, the origin of the symmetry breaking resides in the fact that the modified scalar field potential may have non-degenerate vacuua and these non-degenerate vacuua determine the cosmological constant on both sides of the brane. At last, in order to explore the particle motion in the neighborhood of the brane, the geodesic equations along the fifth dimension are studied.

  14. Sea ice thickness and recent Arctic warming

    Science.gov (United States)

    Lang, Andreas; Yang, Shuting; Kaas, Eigil

    2017-01-01

    The climatic impact of increased Arctic sea ice loss has received growing attention in the last years. However, little focus has been set on the role of sea ice thickness, although it strongly determines surface heat fluxes. Here ensembles of simulations using the EC-Earth atmospheric model (Integrated Forecast System) are performed and analyzed to quantify the atmospheric impacts of Arctic sea ice thickness change since 1982 as revealed by the sea ice model assimilation Global Ice-Ocean Modeling and Assimilation System. Results show that the recent sea ice thinning has significantly affected the Arctic climate, while remote atmospheric responses are less pronounced owing to a high internal atmospheric variability. Locally, the sea ice thinning results in enhancement of near-surface warming of about 1°C per decade in winter, which is most pronounced over marginal sea ice areas with thin ice. This leads to an increase of the Arctic amplification factor by 37%.

  15. Visual perception of thick transparent materials.

    Science.gov (United States)

    Fleming, Roland W; Jäkel, Frank; Maloney, Laurence T

    2011-06-01

    Under typical viewing conditions, human observers readily distinguish between materials such as silk, marmalade, or granite, an achievement of the visual system that is poorly understood. Recognizing transparent materials is especially challenging. Previous work on the perception of transparency has focused on objects composed of flat, infinitely thin filters. In the experiments reported here, we considered thick transparent objects, such as ice cubes, which are irregular in shape and can vary in refractive index. An important part of the visual evidence signaling the presence of such objects is distortions in the perceived shape of other objects in the scene. We propose a new class of visual cues derived from the distortion field induced by thick transparent objects, and we provide experimental evidence that cues arising from the distortion field predict both the successes and the failures of human perception in judging refractive indices.

  16. Thickness dependent thermal conductivity of gallium nitride

    Science.gov (United States)

    Ziade, Elbara; Yang, Jia; Brummer, Gordie; Nothern, Denis; Moustakas, Theodore; Schmidt, Aaron J.

    2017-01-01

    As the size of gallium nitride (GaN) transistors is reduced in order to reach higher operating frequencies, heat dissipation becomes the critical bottleneck in device performance and longevity. Despite the importance of characterizing the physics governing the thermal transport in thin GaN films, the literature is far from conclusive. In this letter, we report measurements of thermal conductivity in a GaN film with thickness ranging from 15-1000 nm grown on 4H-SiC without a transition layer. Additionally, we measure the thermal conductivity in the GaN film when it is 1 μm-thick in the temperature range of 300 < T < 600 K and use a phonon transport model to explain the thermal conductivity in this film.

  17. Properties of conductive thick-film inks

    Science.gov (United States)

    Holtze, R. F.

    1972-01-01

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

  18. 30 CFR 816.105 - Backfilling and grading: Thick overburden.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Backfilling and grading: Thick overburden. 816...-SURFACE MINING ACTIVITIES § 816.105 Backfilling and grading: Thick overburden. (a) Definition. Thick... surrounding terrain. (b) Performance standards. Where thick overburden occurs within the permit area,...

  19. Pioneer Venus polarimetry and haze optical thickness

    Science.gov (United States)

    Knibbe, W. J. J.; Wauben, W. M. F.; Travis, L. D.; Hovenier, J. W.

    1992-01-01

    The Pioneer Venus mission provided us with high-resolution measurements at four wavelengths of the linear polarization of sunlight reflected by the Venus atmosphere. These measurements span the complete phase angle range and cover a period of more than a decade. A first analysis of these data by Kawabata et al. confirmed earlier suggestions of a haze layer above and partially mixed with the cloud layer. They found that the haze exhibits large spatial and temporal variations. The haze optical thickness at a wavelength of 365 nm was about 0.06 at low latitudes, but approximately 0.8 at latitudes from 55 deg poleward. Differences between morning and evening terminator have also been reported by the same authors. Using an existing cloud/haze model of Venus, we study the relationship between the haze optical thickness and the degree of linear polarization. Variations over the visible disk and phase angle dependence are investigated. For that purpose, exact multiple scattering computations are compared with Pioneer Venus measurements. To get an impression of the variations over the visible disk, we have first studied scans of the polarization parallel to the intensity equator. After investigating a small subset of the available data we have the following results. Adopting the haze particle characteristics given by Kawabata et al., we find a thickening of the haze at increasing latitudes. Further, we see a difference in haze optical thickness between the northern and southern hemispheres that is of the same order of magnitude as the longitudinal variation of haze thickness along a scan line. These effects are most pronounced at a wavelength of 935 nm. We must emphasize the tentative nature of the results, because there is still an enormous amount of data to be analyzed. We intend to combine further polarimetric research of Venus with constraints on the haze parameters imposed by physical and chemical processes in the atmosphere.

  20. Conduction Mechanisms in Thick Film Microcircuits

    Science.gov (United States)

    1975-12-01

    AREMCO 3100 Screen Printing Machine 53 3.11 Squeegee Design 55 3.12 Effect of Screen Printer Parameters on Filin Weight Deposited 59 3.13 Variation of...deviation of printing performance. This is discussed in greater detail sIfter the materials and machine are described. 3.5.2 Screening Material and...beyoni the range of monolithic technology can be satisfied by combining monolithic and thick film technologies. Design functions such as flexibility

  1. Thick brane world model from perfect fluid

    CERN Document Server

    Ivashchuk, V D

    2001-01-01

    A (1 + d)-dimensional thick "brane world" model with varying Lambda-term is considered. The model is generalized to the case of a chain of Ricci-flat internal spaces when the matter source is an anisotropic perfect fluid. The "horizontal" part of potential is obtained in the Newtonian approximation. In the multitemporal case (with a Lambda-term) a set of equations for potentials is presented.

  2. Development of plating thickness standards. Milestone report

    Energy Technology Data Exchange (ETDEWEB)

    Russell, R.J.

    1978-01-01

    Standards which are unavailable from the National Bureau of Standards were developed to support the nondestructive measurement of plating thickness. Their fabrication, measurement, certification, and calibration-recall schedule are discussed. Reference standards that have been put into service include aluminum/Kapton, silver/copper, tin/steel, gold/silver, cadmium/Kovar, silver/iron, rhodium/copper, and gold/ceramic. 6 figures, 3 tables.

  3. A de Sitter tachyon thick braneworld

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-02-01

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

  4. Epicardial fat thickness in patients with rheumatoid arthritis.

    Science.gov (United States)

    Fatma, Erdem; Bunyamin, Koc; Savas, Sarikaya; Mehmet, Ucar; Selma, Yazıcı; Ismail, Boyraz; Sabri, Caglar; Gulzade, Ozyalvacli; Ibrahim, Donmez; Mehmet, Yazici

    2015-06-01

    Epidemiologic data indicates that rheumatoid arthritis is an independent risk factor for cardiovascular disease. Epicardial adipose tissue is a novel cardio-metabolic risk factor. Our aim was to evaluate epicardial fat thickness (EFT) using echocardiography in patients with rheumatoid arthritis compared to healthy control subjects. Secondly, we investigated relationship between epicardial fat thickness and clinical and echocardiographic parameters in patients with rheumatoid arthritis. The study population included 76 consecutive patients with rheumatoid arthritis (64 female; mean age, 53 ±11 years, median disease duration, 7.8 years) and 50 healthy subjects as controls (39 female; mean age, 52 ± 6 years). All patients underwent echocardiography to assess left ventricular diastolic dysfunction, left ventricular hypertrophy and EFT. All values were compared between groups. EFT was higher in rheumatoid arthritis patients than in healthy controls (0.66±0.20 vs. 0.54±0.18; p= 0.003). Thickness of Intra Ventricular Septum (IVS) (1.1±0.06 and 9.8±0.08; p=0.001) and posterior wall (PW) (0.98±0.05 and 0.93±0.08; p=0.015) was higher in patients with rheumatoid arthritis compared to healthy controls. Early diastolic myocardiac peak velocity or late diastolic mitral peak velocity (E/A) ratio was lower in rheumatoid arthritis patients compared to healthy patients (1.1 ±0.8 and 1.24±0.1 p=0.001) as well as, E/e' was higher in Rheumatoid arthritis (RA) patients than healthy patients. (E/e':8.7±1.6 and 8.0±1.4 p=0.020). In patients with rheumatoid arthritis, EFT was positively correlated with hypertension and duration of disease and E/e' (r: 0.10, p: 0.010, r: 0.306, p: 0.004 and r: 0.465 p: 0.007 respectively) and EFT was negatively correlated with E/A (r: -.262 p:0.022). To our knowledge, this is the first report about epicardial adipose tissue in rheumatoid arthritis patients. Epicardial fat thickness as an indicator of cardiovascular involvement was higher in

  5. Ply Thickness Fiber Glass on Windmill Drive Salt Water Pump

    Science.gov (United States)

    Sifa, Agus; Badruzzaman; Suwandi, Dedi

    2016-04-01

    Factors management of salt-making processes need to be considered selection of the location and the season is very important to support the efforts of salting. Windmills owned by the farmers are still using wood materials are made each year it is not effectively done and the shape of windmills made not in accordance with the requirements without considering the wind speed and the pumping speed control influenced by the weight and size of windmill, it affects the productivity of salt. to optimize the function of windmills on pumping salt water by change the material blade on the wheel by using a material composite, composite or fiberglass are used for blades on windmills made of a material a mixture of Epoxy-Resin and Matrix E-Glass. The mechanical characteristics of the power of his blade one of determining the materials used and the thickness of the blade, which needed a strong and lightweight. The calculation result thick fiberglass with a composition of 60% fiber and 40% epoxy, at a wind speedof area salt fields 9 m/s, the drag force that occurs at 11,56 kg, then the calculation result by 0,19 mm thick with a layer of 10, the total thickness of 1,9 mm, with a density of 1760 kg/m3, mechanical character of elongated elastic modulus of 46200 MPa, modulus of transverse elasticity of 10309,6 MPa, shear modulus of 3719 MPa and Poisson ratio of 0,31, then the calculation using the finite element ABAQUS obtained critical point at the confluence of the blade to the value of Von Mises tension was happening 1,158e9 MPa maximum and minimum 2,123e5 MPa, for a maximum value of displacement occurred condition at the tip of the blade. The performance test results windmills at a wind speed of 5,5 m/s wind power shows that occur 402,42 watts and power turbines produced 44,21 watt, and TSR 0,095 and the value Cp of 0,1, test results windmill in salt fields in the beginning rotation windmill lighter, able to move above wind speed of 5.5 m/s.

  6. Laboratory experiments on diffusive convection layer thickness and its oceanographic implications

    Science.gov (United States)

    Guo, Shuang-Xi; Zhou, Sheng-Qi; Qu, Ling; Lu, Yuan-Zheng

    2016-10-01

    We studied the thickness of diffusive convective layers that form when a linearly stratified fluid is subjected to heating from below in the laboratory. The thickness of the bottom convecting layer is much larger than subsequent layers. These thicknesses are systematically identified and used to examine the available convecting layer thickness parameterizations, which are consisted of the measured heat flux F (or thermal buoyancy flux qT), initial stratification N, density ratio Rρ, thermal diffusivity κT, etc. Parameterization with an intrinsic length scale >(qT3κ/TN8)1/4 is shown to be superior. Including the present laboratory convecting layer thicknesses and those observed in oceans and lakes, where layer thickness ranges from 0.01 to 1000 m, the parameterization is updated as H=C>(Rρ-1>)2>(qT3κ/TN8)1/4, where C = 38.3 for the bottom convective layer and 10.8 for the subsequent layers. Different prefactors are proposed to be attributed to different convective instabilities induced by different boundary conditions.

  7. Experimental Study on the Effect of Steel-fibre in Concrete Thick Cap

    Institute of Scientific and Technical Information of China (English)

    LU Hailin; ZHANG Mingyuan; LI Zhongxian

    2007-01-01

    The effect of steel fibre used in concrete was systematically analyzed by model testing of 30 2-pile thick caps of steel-fibre reinforced concrete, in which the model scale was 1:5. The experiment system composed of a loading device, strain measurement system and a data-acquisition system was used, also an electromechanic centigrade scale, a lens and a YJ-25 static resistance strainometer were used.The experimental results show that the volumetric rate of steel fibre and draw ratio have an important influence on its load-bearing capacity. The incorporation of steel fibre can effectively improve the extension and reduce the thickness of the caps.

  8. Clinical evaluation of low vision and central foveal thickness in highly myopic cataract eyes after phacoemulsification

    Directory of Open Access Journals (Sweden)

    Ji-Li Chen

    2015-07-01

    Full Text Available AIM:To retrospectively evaluate central foveal thickness in highly myopic eyes with best correct visual acuity(BCVAMETHODS: In this retrospective clinical study, we consecutively recruited 70 low highly myopic cataract subjects(70 eyesunderwent Phaco. Postoperative visits were performed at 1wk, 1 and 3mo. Postoperative BCVA were recorded and further divided into 2 groups with BCVARESULTS: The ratio of BCVAPr=-0.716, PCONCLUSION: In this study, BCVA is improved after 3mo follow up. There has significant correlation between postoperative BCVA and central foveal thickness.

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

    DEFF Research Database (Denmark)

    Sørensen, Rene; Lund, Erik

    2015-01-01

    This paper presents a new gradient based method for performing discrete material and thickness optimization of laminated composite structures. The novelty in the new method lies in the application of so-called casting constraints, or thickness filters in this context, to control the thickness...... govern the presence of material in each layer through the thickness of the laminate. Combined with an in-plane density filter, the method enables manufacturers to control the length scale of the geometry while obtaining near discrete designs. Together with the applied manufacturing constraints it is now...... possible for manufacturers to steer the design towards a higher level of manufacturability. The method is demonstrated for mass minimization with displacement and manufacturing constraints. The results show that the method indeed is capable of obtaining near discrete designs which obey the governing...

  10. Thick Brane Worlds Arising From Pure Geometry

    CERN Document Server

    Cardenas, R; Cardenas, Rolando; Quiros, Israel

    2002-01-01

    We study a non-Riemannian modification of 5-dimensional Kaluza-Klein theory. In our proposal the Riemannian structure of the five-dimensional manifold is replaced by a Weyl-integrable one. In this context a 4-dimensional Poincar$\\grave{e}$ invariant solution is studied. A spacetime structure with two thick (smooth) branes separated in the extra dimension arises. The massless graviton is located in one of the thick branes at the origin, meanwhile the matter degrees of freedom are confined to the other brane. Due to the small overlap of the graviton's wave-function with the second thick brane, the model accounts for a resolution of the mass hierarchy problem a la Randall-Sundrum. Although, initially, no assumptions are made about the topology of the extra dimension, the solution found yields an extra space that is effectivelly compact and respects $Z_2$ symmetry. Unlike other models with branes, the spectrum of massive Kaluza-Klein states is quantized and free of tachyonic modes.

  11. Decreased central corneal thickness in ankylosing spondylitis.

    Science.gov (United States)

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

    2014-04-01

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

  12. Nano-Hydroxyapatite Thick Film Gas Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Khairnar, Rajendra S.; Mene, Ravindra U.; Munde, Shivaji G.; Mahabole, Megha P. [School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606 (India)

    2011-12-10

    In the present work pure and metal ions (Co and Fe) doped hydroxyapatite (HAp) thick films have been successfully utilized to improve the structural, morphological and gas sensing properties. Nanocrystalline HAp powder is synthesized by wet chemical precipitation route, and ion exchange process is employed for addition of Co and Fe ions in HAp matrix. Moreover, swift heavy ion irradiation (SHI) technique is used to modify the surface of pure and metal ion exchanged HAp with various ion fluence. The structural investigation of pure and metal ion exchanged HAp thick films are carried out using X-ray diffraction and the presence of functional group is observed by means FTIR spectroscopy. Furthermore, surface morphology is visualized by means of SEM and AFM analysis. CO gas sensing study is carried out for, pure and metal ions doped, HAp thick films with detail investigation on operating temperature, response/recovery time and gas uptake capacity. The surface modifications of sensor matrix by SHI enhance the gas response, response/recovery and gas uptake capacity. The significant observation is here to note that, addition of Co and Fe in HAp matrix and surface modification by SHI improves the sensing properties of HAp films drastically resulting in gas sensing at relatively lower temperatures.

  13. Precision of hyaline cartilage thickness measurements

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, K.; Buckwalter, K.; Helvie, M.; Niklason, L.; Martel, W. (Univ. of Michigan Hospitals, Ann Arbor, MI (United States). Dept. of Radiology)

    1992-05-01

    Measurement of cartilage thickness in vivo is an important indicator of the status of a joint as the various degenerative and inflammatory arthritides directly affect the condition of the cartilage. In order to assess the precision of thickness measurements of hyaline articular cartilage, we undertook a pilot study using MR imaging, plain radiography, and ultrasonography (US). We measured the cartilage of the hip and knee joints in 10 persons (4 healthy volunteers and 6 patients). The joints in each patient were examined on two separate occasions using each modality. In the hips a swell as the knee joints, the most precise measuring method was plain film radiography. For radiographs of the knees obtained in the standing position, the coefficient of variation was 6.5%; in the hips this figure was 6.34%. US of the knees and MR imaging of the hips were the second best modalities in the measurement of cartilage thickness. In addition, MR imaging enabled the most complete visualization of the joint cartilage. (orig.).

  14. Optically-thick accretion discs with advection

    Institute of Scientific and Technical Information of China (English)

    陈林红; 吴枚; 尚仁成

    2002-01-01

    The structures of optically-thick accretion discs with radial advection have been investigated by the iteration and integration algorithms. The advective cooling term changes mostly the inner part of disc solution, and even results in an optically-thick advection-dominated accretion flow (ADAF). Three distinct branches-the outer Shakura-Sunyaev disc (SSD), the inner ADAF and the middle transition layer-are found for a super-Eddington disc. The SSD-ADAF transition radius can be estimated as 18(M/ME)RG where RG is the Schwarzschild radius, M is the mass accretion rate and ME is the Eddington accretion rate. SSD solutions calculated with the iteration and integration methods are identical, while ADAF solutions obtained by these two methods differ greatly. Detailed algorithms and their differences have been analysed. The iteration algorithm is not self-consistent, since it implies that the dimensionless advection factor ξ is invariant, but in the inner ADAF region the variation of ξ is not negligible. The integration algorithm is always effective for the whole region of an optically-thick disc if the accretion rate is no smaller than 10-4ME. For optically-thin discs, the validity of these two algorithms is different. We suggest that the integration method be employed to calculate the global solution of a disc model without assuming ξ to be a constant. We also discuss its application to the emergent continuum spectrum in order to explain observational facts.

  15. Cortical Thickness Changes Associated with Photoparoxysmal Response

    DEFF Research Database (Denmark)

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

    2014-01-01

    Photoparoxysmal response (PPR) is an EEG trait of spike and spike-wave discharges in response to photic stimulation that is closely linked to idiopathic generalized epilepsy (IGE). In our previous studies we showed that PPR is associated with functional alterations in the occipital and frontal co......) and compared these groups with a group of PPR-negative-healthy-controls (HC, n = 17; 15.3 ± 3.6 years; 6 males). Our results revealed an increase of cortical thickness in the occipital, frontal and parietal cortices bilaterally in PPR-positive-subjects in comparison to HC. Moreover PPR......-positive-subjects presented a significant decrease of cortical thickness in the temporal cortex in the same group contrast. IGE patients exhibited lower cortical thickness in the temporal lobe bilaterally and in the right paracentral region in comparison to PPR-positive-subjects. Our study demonstrates structural changes...... in the occipital lobe, frontoparietal regions and temporal lobe, which also show functional changes associated with PPR. Patients with epilepsy present changes in the temporal lobe and supplementary motor area....

  16. Choroidal Thickness Measured by Spectral Domain Optical Coherence Tomography: Factors Affecting Thickness in Glaucoma Patients

    Science.gov (United States)

    Maul, Eugenio A.; Friedman, David S.; Chang, Dolly S.; Boland, Michael V.; Ramulu, Pradeep Y.; Jampel, Henry D.; Quigley, Harry A.

    2011-01-01

    Purpose To measure choroidal thickness and to determine parameters associated with it. Design Cross-sectional study. Participants Seventy-four glaucoma patients and glaucoma suspects. Methods Spectral domain optical coherence tomography (SDOCT) scans were obtained to estimate average choroidal thickness in a group of glaucoma suspects and glaucoma patients. Average thickness was calculated from enhanced depth SDOCT images and manually analyzed with Image J software. Open angle glaucoma, open angle glaucoma suspect, primary angle closure glaucoma, primary angle closure, and primary angle closure suspect were defined by published criteria. Glaucoma suspects had normal visual fields bilaterally. Glaucoma was defined by specific criteria for optic disc damage and visual field loss in at least one eye. The most affected eye was analyzed for comparisons across individuals, while right/left and upper half/lower half comparisons were made to compare thickness against degree of visual field damage. Main Outcome Measured Average macular and peripapillary choroidal thickness measured using SDOCT. Results The choroidal-scleral interface (CSI) was visualized in 86% and 96% of the macular and peripapillary scans, respectively. In multivariable linear regression analysis, the macular choroid was significantly thinner in association with 4 features: longer eyes (22 µm per mm longer [95% confidence Interval (CI): −33, −11]), older individuals (31 µm thinner per decade older [95% CI: −44 −17]), lower diastolic ocular perfusion pressure (26 µm thinner per 10 mmHg lower [95% CI: 8, 44]), and thicker central corneas (6 µm per 10 µm thicker cornea [95% CI: −10, 0]). The choroid was not significantly thinner in glaucoma patients than in suspects (14 µm [95% CI: −54, 26], p=0.5). Peripapillary choroidal thickness was not significantly different between glaucomaand suspect patients. Thickness was not associated with damage severity as estimated by visual field mean

  17. Cranial vault thickness in primates: Homo erectus does not have uniquely thick vault bones.

    Science.gov (United States)

    Copes, Lynn E; Kimbel, William H

    2016-01-01

    Extremely thick cranial vaults have been noted as a diagnostic characteristic of Homo erectus since the first fossil of the species was identified, but relatively little work has been done on elucidating its etiology or variation across fossils, living humans, or extant non-human primates. Cranial vault thickness (CVT) is not a monolithic trait, and the responsiveness of its layers to environmental stimuli is unknown. We obtained measurements of cranial vault thickness in fossil hominins from the literature and supplemented those data with additional measurements taken on African fossil specimens. Total CVT and the thickness of the cortical and diploë layers individually were compared to measures of CVT in extant species measured from more than 500 CT scans of human and non-human primates. Frontal and parietal CVT in fossil primates was compared to a regression of CVT on cranial capacity calculated for extant species. Even after controlling for cranial capacity, African and Asian H. erectus do not have uniquely high frontal or parietal thickness residuals, either among hominins or extant primates. Extant primates with residual CVT thickness similar to or exceeding H. erectus (depending on the sex and bone analyzed) include Nycticebus coucang, Perodicticus potto, Alouatta caraya, Lophocebus albigena, Galago alleni, Mandrillus sphinx, and Propithecus diadema. However, the especially thick vaults of extant non-human primates that overlap with H. erectus values are composed primarily of cortical bone, while H. erectus and other hominins have diploë-dominated vault bones. Thus, the combination of thick vaults comprised of a thickened diploë layer may be a reliable autapomorphy for members of the genus Homo.

  18. Equivalent Circuit Model for Thick Split Ring Resonators and Thick Spiral Resonators

    CERN Document Server

    Mancera, Laura Maria Pulido

    2014-01-01

    A simple theoretical model which provides circuit parameters and resonance frequency of metallic thick resonators is presented. Two different topologies were studied: the original Pendry's SRR and spiral resonators of two and three turns. Theoretical computations of resonant frequencies are in good agreement with values obtained with a commercial electromagnetic solver. The model could be helpful for designing thick frequency selective surfaces (FSS) based on this types of resonators, so called metasurfaces.

  19. The Influence of Waist Thickness of Dolosse on the Hydraulic Stability of Dolosse Armour

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Brejnegaard-Nielsen, Torben

    1987-01-01

    The paper presents results from experiments with Dolosse having the same mass and volume but with different waist thickness to height ratios. The armour was exposed to irregular waves simulating one storm with increasing wave heights and the effect of waist to height ratio on the hydraulic...... stability was studied. A low packing density of approximately 0.65 was used corresponding to a two-layer armour with high porosity. From the results it is concluded that the hydraulic stability of Dolos armour is not very sensitive to variations in the waist to height ratio. Only for damage levels exceeding...... displacement of approximately 5% of the armour blocks in the most exposed area there seems to be a significant decrease in hydraulic stability with increasing waist to height ratio. Thus the waist ratio only influences the residual hydraulic stability. Based on a short discussion of stressed in armour units...

  20. Increased visceral adiposity and cortisol to cortisone ratio in adults with congenital lifetime isolated GH deficiency.

    Science.gov (United States)

    Gomes-Santos, Elenilde; Salvatori, Roberto; Ferrão, Thiago O; Oliveira, Carla R P; Diniz, Rachel D C A; Santana, João A M; Pereira, Francisco A; Barbosa, Rita A A; Souza, Anita H O; Melo, Enaldo V; Epitácio-Pereira, Carlos C; Oliveira-Santos, Alécia A; Oliveira, Ingrid A S; Machado, Julianne A; Santana-Júnior, Francisco J; Barreto-Filho, José A S; Aguiar-Oliveira, Manuel H

    2014-09-01

    Adult-onset GH deficiency (GHD) increases visceral adiposity and the activity of the enzyme 11β-hydroxysteroid dehydrogenase, which converts cortisone (E) to cortisol (F), both linked to insulin resistance and increased cardiovascular risk. Conversely, we reported that adults with congenital isolated GHD (IGHD) have increased insulin sensitivity. To assess the type of fat distribution and the amount of visceral and sc fat and to correlate them to the F/E ratio in adults with untreated IGHD due to a mutation in the GHRH receptor gene. Body composition was assessed by dual-energy x-ray absorptiometry, thickness of sc and visceral fat was measured by sonography, and serum F and E were measured in 23 IGHD subjects and 21 age-matched controls. Waist/hip ratio (WHR), trunk fat, and trunk/extremity fat (TR/EXT) ratio were higher in IGHD subjects. Visceral fat index (VFI) (but not sc fat index [SFI]) was higher in IGHD. F and F/E ratio were also higher in IGHD. In all 44 individuals, WHR correlated with TR/EXT ratio, thickness of visceral fat, VFI/SFI ratio, F, and F/E ratio. TR/EXT ratio correlated with visceral fat thickness, VFI/SFI ratio, and F. Age had a significant effect on VFI and on F/E ratio. Body mass index SD score and WHR have a similar significant effect on TR/EXT ratio and on F/E ratio. Lifetime congenital untreated IGHD causes increased visceral adiposity with a high F/E ratio. However, the increased insulin sensitivity suggests that visceral adiposity needs a minimal GH secretion to translate into increased insulin resistance.

  1. Thick vortices in SU(2) lattice gauge theory

    OpenAIRE

    Cheluvaraja, Srinath

    2004-01-01

    Three dimensional SU(2) lattice gauge theory is studied after eliminating thin monopoles and the smallest thick monopoles. Kinematically this constraint allows the formation of thick vortex loops which produce Z(2) fluctuations at longer length scales. The thick vortex loops are identified in a three dimensional simulation. A condensate of thick vortices persists even after the thin vortices have all disappeared. The thick vortices decouple at a slightly lower temperature (higher beta) than t...

  2. DYNAMIC TEACHING RATIO PEDAGOGIC MODEL

    Directory of Open Access Journals (Sweden)

    Chen Jiaying

    2010-11-01

    Full Text Available This paper outlines an innovative pedagogic model, Dynamic Teaching Ratio (DTR Pedagogic Model, for learning design and teaching strategy aimed at the postsecondary technical education. The model draws on the theory of differential learning, which is widely recognized as an important tool for engaging students and addressing the individual needs of all students. The DTR model caters to the different abilities, interest or learning needs of students and provides different learning approaches based on a student’s learning ability. The model aims to improve students’ academic performance through increasing the lecturer-to-student ratio in the classroom setting. An experimental case study on the model was conducted and the outcome was favourable. Hence, a large-scale implementation was carried out upon the successful trial run. The paper discusses the methodology of the model and its application through the case study and the large-scale implementation.

  3. Cortical thickness difference across the central sulcus visualized in the presence of vasogenic edema

    Energy Technology Data Exchange (ETDEWEB)

    Togao, Osamu [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582 (Japan)], E-mail: togao@dr.hosp.kyushu-u.ac.jp; Yoshiura, Takashi; Mihara, Futoshi; Noguchi, Tomoyuki; Hiwatashi, Akio; Yamashita, Koji; Yoshitake, Tadamasa; Honda, Hiroshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582 (Japan)

    2008-05-15

    Purpose: To confirm the cortical thickness difference across the central sulcus (CS) visualized in the presence of vasogenic edema on MRI. Materials and methods: T2-weighted images of 70 cerebral hemispheres showing vasogenic edema infiltrating into subcortical white matter around the CS were studied retrospectively. Two neuroradiologists measured the cortical thickness of the anterior and posterior banks of the CS, precentral sulci (PrCS), and postcentral sulci (PoCS). Additionally, we compared the cortical thickness of the anterior and posterior banks of each sulcus visually using a grading scale. Results: On T2-weighted images, the cerebral cortex was highlighted by a high signal-intensity vasogenic edema in the adjacent white matter, and its thickness was readily measurable. The unique cortical thickness difference between the anterior and posterior banks of the CS were confirmed with measurements of 2.67 and 1.48 mm (p < 0.0001). The cortical measurements across other cerebral sulci were 2.04 and 1.95 mm (NS) for the PrCS, and 1.67 and 1.77 mm (NS) for the PoCS. The cortical thickness ratios were 1.86 for the CS, 1.05 for the PrCS, and 0.96 for the PoCS. On visual evaluation, the anterior bank of the CS was thicker than the posterior bank in 93% (65/70). For the PrCS and PoCS, the thickness of the anterior and posterior banks appeared to be equal in over 70% of the patients. Conclusion: A prominent cortical thickness difference across the CS in the presence of vasogenic edema was confirmed. This finding is considered to facilitate the identification of the CS in patients with brain tumors.

  4. Photoimageable Polyimide: A Dielectric Material For High Aspect Ratio Structures

    Science.gov (United States)

    Cech, Jay M.; Oprysko, Modest M.; Young, Peter L.; Li, Kin

    1986-07-01

    Polyimide has been identified as a useful material for microelectronic packaging because of its low dielectric constant and high temperature stability. Difficulties involved with reactive ion etching (RIE), a conventional technique for patterning thick polyimide films (thickness greater than 5 microns) with vertical walls, can be overcome by using photimageable polyimide precursors. The processing steps are similar to those used with negative photoresists. EM Chemical's HTR-3 photosensitive polyimide has been spun on up to a thickness of 12 microns. Exposure with a dose of 780 mJcm-2 of ultraviolet light, followed by spin development produces clean patterns as small as 5 microns corresponding to an aspect ratio of 2.4. When the patterned precursor is heated, an imidization reaction occurs converting the patterned film to polyimide. Baking to ca. 400 degrees C results in substantial loss in the thickness and in line width. However, shrinkage occurs reproducibly so useful rules for mask design can be formulated. Near vertical wall structures can be fabricated by taking advantage of the optical and shrinkage properties of the polyimide precursor. After development, an undercut wall profile can be produced since the bottom of the film receives less exposure and is hence more soluble in the developer. During heating, lateral shrinkage pulls the top of the film inward producing a vertical wall since the bottom is fixed to the substrate by adhesion. As a result, fully cured polyimide structures with straight walls and aspect ratios greater than one can be obtained. Dielectric properties of the fully imidized films were investigated with capacitor test structures. A relative dielectric constant of 3.3 and a loss tangent of .002 were measured at 20 kHz. It was also found that the dielectric constant increases as a linear function of relative humidity.

  5. Formation of High Aspect Ratio Microcoil Using Dipping Method

    Science.gov (United States)

    Noda, Daiji; Yamashita, Shuhei; Matsumoto, Yoshifumi; Setomoto, Masaru; Hattori, Tadashi

    Coils are used in many electronic devices as inductors in mobile units such as mobile phone, digital cameras, etc. Inductance and quality factor of coils are very important value of the performance. Therefore, the requests for coils are small size, high inductance, low power consumption, etc. However, coils are unsuitable for miniaturization because of its structure. Therefore, we have proposed and developed the microcoils of high aspect ratio with the dipping method and an X-ray lithography technique. In dipping method, centrifugal force and highly viscous photoresist solution were key points to evenly apply resist in the form of thick film on metal bar. The film thickness of resist on bar was achieved about 50 μm after single coating. Using these techniques, we succeeded in creating threaded groove structure with 10 μm lines and spaces on 1 mm brass bar. In this case, the aspect ratio was achieved five. It is very expected the high performance microcoil with high aspect ratio lines could be manufactured in spite of the miniature size.

  6. An experimental evaluation of the Hamrock and Dowson minimum film thickness equation for fully flooded EHD point contacts

    Science.gov (United States)

    Koye, K. A.; Winer, W. O.

    1980-08-01

    Fifty-seven measurements of the minimum lubricant film separating the elastohydrodynamically lubricated point contact of a steel crowned roller and a flat sapphire disk were made by an optical interferometry technique. The data collected were used to evaluate the Hamrock and Dowson minimum EHD film thickness model over a practical range of contact ellipticity ratio where the major axis of the contact ellipse is aligned both parallel and perpendicular to the direction of motion. A statistical analysis of the measured film thickness data showed that on the average the experimental data averaged 30 percent greater film thickness than the Hamrock and Dowson model predicts.

  7. Corrigendum to "Geant4 validation of neutron production on thick targets bombarded with 120 GeV protons" [Nucl. Instr. Meth. B 358 (2015) 245-250

    Science.gov (United States)

    Sabra, Mohammad S.

    2016-09-01

    In the paper by Mohammad S. Sabra, due to a mixup, wrong calculations for NEPR ratios, normalized to 20 cm-thick copper, for 40 cm and 60 cm-thick copper at 30° for QGSP-BIC, QGSP-BERT, QGSP-INCLXX, and SHIELDING were published in Table 2. The correct values are listed in the revised Table 2 as below.

  8. Envera Variable Compression Ratio Engine

    Energy Technology Data Exchange (ETDEWEB)

    Charles Mendler

    2011-03-15

    Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy has already demonstrated a degree of success, downsizing and fuel economy gains are currently limited. With new variable compression ratio technology however, the degree of engine downsizing and fuel economy improvement can be greatly increased. A small variable compression ratio (VCR) engine has the potential to return significantly higher vehicle fuel economy while also providing high power. Affordability and potential for near term commercialization are key attributes of the Envera VCR engine. VCR Technology To meet torque and power requirements, a smaller engine needs to do more work per stroke. This is typically accomplished by boosting the incoming charge with either a turbo or supercharger so that more energy is present in the cylinder per stroke to do the work. With current production engines the degree of engine boosting (which correlates to downsizing) is limited by detonation (combustion knock) at high boost levels. Additionally, the turbo or supercharger needs to be responsive and efficient while providing the needed boost. VCR technology eliminates the limitation of engine knock at high load levels by reducing compression ratio to {approx}9:1 (or whatever level is appropriate) when high boost pressures are needed. By reducing the compression ratio during high load demand periods there is increased volume in the cylinder at top dead center (TDC) which allows more charge (or energy) to be present in the cylinder without increasing the peak pressure. Cylinder pressure is thus kept below the level at which the engine would begin to knock. When loads on the engine are low

  9. Association of carotid artery intima-media thickness with complex aortic atherosclerosis in patients with recent stroke.

    Science.gov (United States)

    Fasseas, Panayotis; Brilakis, Emmanouil S; Leybishkis, Biana; Cohen, Marc; Sokil, Alexis B; Wolf, Nelson; Dorn, Rose Lee; Roberts, Andrew; VanDecker, William

    2002-01-01

    This study was undertaken to determine whether carotid intima-media thickness can predict complex aortic atherosclerosis. A retrospective review was conducted of 64 consecutive patients who underwent transesophageal echocardiography and carotid ultrasonography for evaluation of recent ischemic stroke at MCP Hahnemann University, Medical College of Pennsylvania Hospital between January 1, 1999, and December 31, 1999. The mean age was 65+/-14 years and 59% of the patients were women. Thirty-nine patients (61%) had carotid atherosclerosis (defined as an intima-media thickness > or =1 mm) and seven patients (11%) had complex aortic atherosclerosis (defined as the presence of protruding atheroma > or =4 mm thick, mobile atherosclerotic debris, or plaque ulceration in any aortic segment by transesophageal echocardiography). Compared to patients without complex aortic atherosclerosis, patients with complex aortic atherosclerosis were more likely to have hypercholesterolemia (19% vs 57%, p = 0.05) and a carotid intima-media thickness of 2 mm or greater (35% vs 86%, p = 0.02). A carotid intima-media thickness of 2 mm or more had 86% sensitivity, 65% specificity, 23% positive predictive value, 97% negative predictive value, 2.5 positive likelihood ratio, and 0.22 negative likelihood ratio for the diagnosis of complex aortic atherosclerosis. Carotid intimamedia thickness measurement can be used to noninvasively estimate the probability of complex aortic atherosclerosis. A carotid intima-media thickness less than 2 mm makes complex aortic atherosclerosis very unlikely.

  10. Spectroscopic metrics allow in situ measurement of mean size and thickness of liquid-exfoliated few-layer graphene nanosheets.

    Science.gov (United States)

    Backes, Claudia; Paton, Keith R; Hanlon, Damien; Yuan, Shengjun; Katsnelson, Mikhail I; Houston, James; Smith, Ronan J; McCloskey, David; Donegan, John F; Coleman, Jonathan N

    2016-02-21

    Liquid phase exfoliation is a powerful and scalable technique to produce defect-free mono- and few-layer graphene. However, samples are typically polydisperse and control over size and thickness is challenging. Notably, high throughput techniques to measure size and thickness are lacking. In this work, we have measured the extinction, absorption, scattering and Raman spectra for liquid phase exfoliated graphene nanosheets of various lateral sizes (90 ≤ 〈L〉 ≤ 810 nm) and thicknesses (2.7 ≤ 〈N〉 ≤ 10.4). We found all spectra to show well-defined dependences on nanosheet dimensions. Measurements of extinction and absorption spectra of nanosheet dispersions showed both peak position and spectral shape to vary with nanosheet thickness in a manner consistent with theoretical calculations. This allows the development of empirical metrics to extract the mean thickness of liquid dispersed nanosheets from an extinction (or absorption) spectrum. While the scattering spectra depended on nanosheet length, poor signal to noise ratios made the resultant length metric unreliable. By analyzing Raman spectra measured on graphene nanosheet networks, we found both the D/G intensity ratio and the width of the G-band to scale with mean nanosheet length allowing us to establish quantitative relationships. In addition, we elucidate the variation of 2D/G band intensities and 2D-band shape with the mean nanosheet thickness, allowing us to establish quantitative metrics for mean nanosheet thickness from Raman spectra.

  11. As thick as three in a bed.

    Science.gov (United States)

    Scheidegger, Christoph

    2016-07-01

    During the evolution of the lichen symbiosis, shifts from one main type of photobiont to another were infrequent (Miadlikowska et al. ) but some remarkable transitions from green algal to diazotrophic cyanobacterial photobionts are known from unrelated fungal clades within the ascomycetes. Cyanobacterial, including tripartite, associations (green algal and cyanobacterial photobionts in one lichen individual) facilitate these holobionts to live as C- and N-autotrophs. Tripartite lichens are among the most productive lichens, which provide N-fertilization to forest ecosystems under oceanic climates (Peltigerales) or deliver low, but ecologically significant N-input into subarctic and alpine soil communities (Lecanorales, Agyriales). In this issue of Molecular Ecology, Schneider et al. (2016) mapped morphometric data against an eight-locus fungal phylogeny across a transition of photobiont interactions from green algal to a tripartite association and used a phylogenetic comparative framework to explore the role of nitrogen-fixing cyanobacteria in size differences in the Trapelia-Placopsis clade (Agyriales). Within the group of tripartite species, the volume of cyanobacteria-containing structures (cephalodia) correlates with thallus thickness in both phylogenetic generalized least squares and phylogenetic generalized linear mixed-effects analyses, and the fruiting body core volume increased ninefold. The authors conclude that cyanobacterial symbiosis appears to have enabled lichens to overcome size constraints in oligotrophic environments such as rock surfaces. The Trapelia-Placopsis clade analyzed by Schneider et al. (2016) is an exciting example of interactions between ecology, phylogeny and lichen biology including development - from thin crustose green algal microlichens to thick placodioid, tripartite macrolichens: as thick as three in a bed (Scott ).

  12. Blackbody Radiation in Optically Thick Gases?

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2014-07-01

    Full Text Available In this work, the claim that optically thick gases can emit as blackbodies is refuted. The belief that such behavior exists results from an improper consideration of heat transfer and reflection. When heat is injected into a gas, the energy is primarily redistributed into translational degrees of freedom and is not used to drive emission. The average kinetic energy of the particles in the system simply increases and the temperature rises. In this respect, it is well-know that the emissivity of a gas can drop with increasing temperature. Once reflection and translation are properly considered, it is simple to understand why gases can never emit as blackbodies.

  13. Proton Straggling in Thick Silicon Detectors

    Science.gov (United States)

    Selesnick, R. S.; Baker, D. N.; Kanekal, S. G.

    2017-01-01

    Straggling functions for protons in thick silicon radiation detectors are computed by Monte Carlo simulation. Mean energy loss is constrained by the silicon stopping power, providing higher straggling at low energy and probabilities for stopping within the detector volume. By matching the first four moments of simulated energy-loss distributions, straggling functions are approximated by a log-normal distribution that is accurate for Vavilov k is greater than or equal to 0:3. They are verified by comparison to experimental proton data from a charged particle telescope.

  14. Choroidal thickness in patients with diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Ünsal E

    2014-03-01

    Full Text Available Erkan Ünsal, Kadir Eltutar, Sibel Zirtiloğlu, Nurhan Dinçer, Sezin Özdoğan Erkul, Hülya GüngelDepartment of Ophthalmology, Istanbul Education and Research Hospital, Istanbul, TurkeyPurpose: The aim of the study reported here was to assess choroidal thickness (CT and central macular thickness (CMT in patients with diabetic retinopathy.Materials and methods: A total of 151 eyes from 80 patients from the retina department of Istanbul Training and Research Hospital who had type 2 diabetes mellitus with diabetic retinopathy were studied retrospectively in this cross-sectional research. Patients were divided into three groups: mild–moderate nonproliferative diabetic retinopathy without macular edema (NPDR, mild–moderate nonproliferative diabetic retinopathy with macular edema (DME, and proliferative diabetic retinopathy (PDR. In addition, 40 eyes of 20 healthy individuals comprised a control group. Choroidal thickness was measured from the posterior edge of the retinal pigment epithelium to the choroid/sclera junction at 500-µm intervals up to 1,500 µm temporal and nasal to the fovea. The CMT measurement was obtained for each eye. Serum hemoglobin A1c (HbA1c levels were measured.Results: The study included 191 eyes, comprising 151 eyes of 80 patients and 40 eyes of 20 healthy individuals. Of the 151 patient eyes, 61 had NPDR, 62 had PDR, and 28 eyes had DME. There was no statistically significant difference in age between the groups (P>0.05. In both the PDR and DME groups, the CT was statistically significantly decreased compared with the control group (P<0.001, P<0.001 for the PDR and DME groups, respectively. The mean CMT in the DME group was increased significantly compared with both the NPDR and PDR groups (P<0.001, P<0.001, respectively. In all three groups, serum HbA1c levels were found to be increased significantly compared with the control group (P=0.000. We found a statistically weak–moderate negative correlation between

  15. Proton straggling in thick silicon detectors

    Science.gov (United States)

    Selesnick, R. S.; Baker, D. N.; Kanekal, S. G.

    2017-03-01

    Straggling functions for protons in thick silicon radiation detectors are computed by Monte Carlo simulation. Mean energy loss is constrained by the silicon stopping power, providing higher straggling at low energy and probabilities for stopping within the detector volume. By matching the first four moments of simulated energy-loss distributions, straggling functions are approximated by a log-normal distribution that is accurate for Vavilov κ ≳ 0.3 . They are verified by comparison to experimental proton data from a charged particle telescope.

  16. OPTIMAL THICKNESS OF A CYLINDRICAL SHELL

    Directory of Open Access Journals (Sweden)

    Paul Ziemann

    2015-01-01

    Full Text Available In this paper an optimization problem for a cylindrical shell is discussed. The aim is to look for an optimal thickness of a shell to minimize the deformation under an applied external force. As a side condition, the volume of the shell has to stay constant during the optimization process. The deflection is calculated using an approach from shell theory. The resulting control-to-state operator is investigated analytically and a corresponding optimal control problem is formulated. Moreover, necessary conditions for an optimal solution are stated and numerical solutions are presented for different examples.

  17. Chemical tailoring of hybrid sol-gel thick coatings as hosting matrix for functional patterned microstructures.

    Science.gov (United States)

    Falcaro, Paolo; Costacurta, Stefano; Malfatti, Luca; Buso, Dario; Patelli, Alessandro; Schiavuta, Piero; Piccinini, Massimo; Grenci, Gianluca; Marmiroli, Benedetta; Amenitsch, Heinz; Innocenzi, Plinio

    2011-02-01

    A phenyl-based hybrid organic - inorganic coating has been synthesized and processed by hard X-ray lithography. The overall lithography process is performed in a two-step process only (X-rays exposure and chemical etching). The patterns present high aspect ratio, sharp edges, and high homogeneity. The coating has been doped with a variety of polycyclic aromatic hydrocarbon functional molecules, such as anthracene, pentacene, and fullerene. For the first time, hard X-rays have been combined with thick hybrid functional coatings, using the sol-gel thick film directly as resist. A new technique based on a new material combined with hard X-rays is now available to fabricate optical devices. The effect due to the high-energy photon exposure has been investigated using FT-IR and Raman spectroscopy, laser scanner, optical profilometer, and confocal and electron microscope. High-quality thick hybrid fullerene-doped microstructures have been fabricated.

  18. 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.

  19. Buckling analysis of thick isotropic plates by using exponential shear deformation theory

    Directory of Open Access Journals (Sweden)

    Sayyad A. S.

    2012-12-01

    Full Text Available In this paper, an exponential shear deformation theory is presented for the buckling analysis of thick isotropic plates subjected to uniaxial and biaxial in-plane forces. The theory accounts for a parabolic distribution of the transverse shear strains across the thickness, and satisfies the zero traction boundary conditions on the top and bottom surfaces of the plate without using shear correction factors. Governing equations and associated boundary conditions of the theory are obtained using the principle of virtual work. The simply supported thick isotropic square plates are considered for the detailed numerical studies. A closed form solutions for buckling analysis of square plates are obtained. Comparison studies are performed to verify the validity of the present results. The effects of aspect ratio on the critical buckling load of isotropic plates is investigated and discussed.

  20. Thickness Measurement of a Film on a Substrate by Low-Frequency Ultrasound

    Institute of Scientific and Technical Information of China (English)

    LI Ming-Xuan; WANG Xiao-Min; MAO Jie

    2004-01-01

    @@ We describe a new simple technique for the low-frequency ultrasonic thickness measurement of an air-backed soft thin layer attached on a hard substrate of finite thickness through the frequency-shifts of the substrate resonances by the substrate-side insonification. A plane compressive wave impinging normally on the substrate surface from a liquid is studied. Low frequency here means an interrogating acoustical wave frequency of less than half of coating to the substrate. Equations for the frequency-shifts are derived and solved by the Newton iterative method and the Taylor expansion method, respectively, indicating satisfactory agreement within the range of interest of thickness ratio of the thin layer to the substrate for a polymer-aluminium structure. An experimental setup is constructed to verify the validity of the technique.

  1. Through Thickness Variation of Cross Shear Rolling Texture in Grain Oriented Silicon Steel

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The texture inhomogeneity in cross shear rolled grain oriented Si steel was investigated by means of the through thickness texture analysis. For the chosen rolling reductions (55%, 66.5%) and mismatch speed ratios (1.0, 1.1,1.3), the deformation textures in various thickness layers consist of three major components, i.e. strong γ-fiber,medium α-fiber and weak η-fiber, and they show an asymmetrical distribution throughout the thickness. The effect of reduction on the texture gradient is found to be more significant at and near the center layer; however, the effect subsurface layers, that may favour the formation of a sharp Goss texture during the subsequent annealing.

  2. (100)-Textured KNN-based thick film with enhanced piezoelectric property for intravascular ultrasound imaging

    Science.gov (United States)

    Zhu, Benpeng; Zhang, Zhiqiang; Ma, Teng; Yang, Xiaofei; Li, Yongxiang; Shung, K. Kirk; Zhou, Qifa

    2015-04-01

    Using tape-casting technology, 35 μm free-standing (100)-textured Li doped KNN (KNLN) thick film was prepared by employing NaNbO3 (NN) as template. It exhibited similar piezoelectric behavior to lead containing materials: a longitudinal piezoelectric coefficient (d33) of ˜150 pm/V and an electromechanical coupling coefficient (kt) of 0.44. Based on this thick film, a 52 MHz side-looking miniature transducer with a bandwidth of 61.5% at -6 dB was built for Intravascular ultrasound (IVUS) imaging. In comparison with 40 MHz PMN-PT single crystal transducer, the rabbit aorta image had better resolution and higher noise-to-signal ratio, indicating that lead-free (100)-textured KNLN thick film may be suitable for IVUS (>50 MHz) imaging.

  3. Measurement of slice thickness using partial volume effect in MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Higashida, Mitsuji; Yamazaki, Masaru [Osaka City Univ. (Japan). Hospital; Ogura, Akio; Inoue, Hiroshi; Hongou, Takaharu

    1998-08-01

    The NEMA standard and AAPM method have been approved for the determination of slice thickness in diagnostic magnetic resonance imaging. In these methods, the slice thickness is obtained as the full width at half maximum of the slice profile. However, these methods are affected by the signal-to-noise ratio (SNR) and pixel size. In addition, the measurement procedure required for accurate evaluation is troublesome. Therefore, a new method of evaluation using the partial volume effect, called the PVE method, is proposed. With the PVE method, slice thickness can be evaluated without the slice profile. A comparison of accuracy and simplicity of measurement is made between the PVE method and the wedge method of the NEMA standard. Results showed the PVE method to be accurate and easier to use than the wedge method. (author)

  4. The Usefulness of Visceral Fat Thickness Measured by Ultrasonography as an Abdominal Obesity Index

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Kyun [Dept. of Diagnostic Radiology, Korealife Daejeon Healthcare Center, Daejeon (Korea, Republic of); Han, Man Seok [Dept. of Diagnostic Radiology, Chungnam National University Hospital, Daejeon (Korea, Republic of)

    2008-09-15

    Abdominal obesity with visceral fat accumulation have been known to be intimately associated with the development of metabolic syndrome. Therefore, it is important to estimate the precise amount of visceral fat. Ultrasonography has been reported that it is a simple and noninvasive method for visceral fat evaluation. Purpose of this study is to evaluate the association of ultrasonographic visceral fat thickness, anthropometric indexes, and risk factor of metabolic syndrome, and to investigate the cut-off value of abdominal visceral fat thickness leading to increased risk of metabolic syndrome. The subject included 200 men and 200 women who visited D healthcare center in Daejeon from January to April 2008. The subcutaneous fat thickness and visceral fat thickness were measured by ultrasonograph. As anthropometric index, we measured body mass index, waist circumference and waist/height ratio. As for the risk factor of metabolic syndrome, we measured blood pressure, high density lipoprotein cholesterol, triglyceride and fasting serum glucose. VFT was significantly correlated with waist circumference, (r=0.683/M, r=0.604/F), waist to height ratio (r=0.633/M, r=0.593/F) and BMI (r=0.621/M, r=0.534/F) in both men and women. In addition it was significantly correlated with Systolic blood pressure (r=0.229/M, r=0.232/F), Diastolic blood pressure ((r=0.285/M, r=0.254/F), high density cholesterol (r=-0.254/M, r=-0.254/F), Triglyceride (r=0.475/M, r=0.411/F), and Fasting blood sugar (r=0.158/M, r=0.234/F) in both men and women. The cut-off value of visceral fat thickness leading to the increased risk of metabolic syndrome was 4.58 cm (sensitivity 89.2%, specificity 71.2%) in men and 3.50 cm (sensitivity 61.2% specificity 80.8%) in women respectively. The odds ratio of the risk of metabolic syndrome was dramatically increased with the abdominal visceral fat thickness level over 6 cm in men and 5 cm in women. The visceral fat thickness using ultrasonography was significantly

  5. Lower muscle regenerative potential in full-thickness supraspinatus tears compared to partial-thickness tears.

    Science.gov (United States)

    Lundgreen, Kirsten; Lian, Oystein Bjerkestrand; Engebretsen, Lars; Scott, Alex

    2013-12-01

    Rotator cuff tears are associated with secondary rotator cuff muscle pathology, which is definitive for the prognosis of rotator cuff repair. There is little information regarding the early histological and immunohistochemical nature of these muscle changes in humans. We analyzed muscle biopsies from patients with supraspinatus tendon tears. Supraspinatus muscle biopsies were obtained from 24 patients undergoing arthroscopic repair of partial- or full-thickness supraspinatus tendon tears. Tissue was formalin-fixed and processed for histology (for assessment of fatty infiltration and other degenerative changes) or immunohistochemistry (to identify satellite cells (CD56+), proliferating cells (Ki67+), and myofibers containing predominantly type 1 or 2 myosin heavy chain (MHC)). Myofiber diameters and the relative content of MHC1 and MHC2 were determined morphometrically. Degenerative changes were present in both patient groups (partial and full-thickness tears). Patients with full-thickness tears had a reduced density of satellite cells, fewer proliferating cells, atrophy of MHC1+ and MHC2+ myofibers, and reduced MHC1 content. Full-thickness tears show significantly reduced muscle proliferative capacity, myofiber atrophy, and loss of MHC1 content compared to partial-thickness supraspinatus tendon tears.

  6. Measurement of choroidal thickness and macular thickness during and after pregnancy

    Institute of Scientific and Technical Information of China (English)

    D?ndü; Melek; Ulusoy; Necati; Duru; Mustafa; Atas; Hasan; Altιnkaynak; Zeynep; Duru; G?khan; A?maz

    2015-01-01

    AIM: To investigate the effect of pregnancy on subfoveal choroidal thickness(SFCT) and macular thickness in both pregnant and not pregnant healthy women.METHODS: Twenty-nine healthy pregnant women in their third trimester and 36 age-matched healthy women were enrolled in a prospective, cross-sectional study.Foveal and parafoveal thickness in the four quadrants and SFCT were measured by optical coherence tomography(OCT) in the healthy pregnant women(i.e.study group) and healthy women(i.e. control group).OCT measurements were again measured 3mo after delivery in the study group.RESULTS: Mean SFCT measurements in the control group, pregnant women of the study group, and after delivery of the study group were 320.86 ±59.18 μm,387.97 ±59.91 μm, and 332.40 ±26.03 μm, respectively.There was a statistically significant difference in the mean SFCT values between pregnant women of the study group and the control group(P =0.000). Foveal and parafoveal thickness values were not statistically significant in either the study or control group.CONCLUSION: SFCT increases during pregnancy and returns to normal range in the three months after delivery. Macular thickness does not show any change during pregnancy.

  7. Odds ratios deconstructed: A new way to understand and explain odds ratios as conditional risk ratios.

    Science.gov (United States)

    Hoppe, Fred M; Hoppe, Daniel J; Walter, Stephen D

    2017-02-01

    The aim of this analysis was to provide an alternative derivation of the odds ratio (OR) to provide an intuitive meaning, freeing it from any mention of odds, which may make it a more useful concept for clinicians to use when describing treatment effect. By examining the four possible combinations of treatment/control and corresponding outcomes, we considered the conditional risk ratio (RR, also known as relative risk) of an event with the treatment compared with an event with the control for pairs of patients for whom treatment and control would yield different results. Both matched and unmatched studies are considered. We found that the OR could be derived as the RR of an outcome with treatment compared with an outcome with control conditional on the treatment and control resulting in different outcomes, thus providing a measure of the net benefit of treatment. It has been claimed that the OR comparing the effect of treatment vs. control does not have the same clinical interpretability as RR because it involves ratios of odds and so is difficult to explain in terms of patient numbers. This new derivation provides an interpretation of the OR as an RR but conditional on treatment and control resulting in different outcomes. This may help explain the reason ORs cause interpretation difficulties in practice. Moreover, the OR may be a more clinically useful parameter to patients because it deals with only those situations where the outcome differs between the two groups. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Gender ratios for reading difficulties

    OpenAIRE

    Hawke, Jesse L.; Olson, Richard K.; Willcutt, Erik G.; Wadsworth, Sally J.; DeFries, John C.

    2009-01-01

    The prevalence of reading difficulties is typically higher in males than females in both referred and research-identified samples, and the ratio of males to females is greater in more affected samples. To explore possible gender differences in reading performance, we analyzed data from 1,133 twin pairs in which at least one member of each pair had a school-history of reading problems and from 684 twin pairs from a comparison sample with no reading difficulties. Although the difference between...

  9. GOLD and the fixed ratio

    Directory of Open Access Journals (Sweden)

    Vestbo J

    2012-09-01

    Full Text Available Jørgen VestboUniversity of Manchester, Manchester, UKI read with interest the paper entitled "Diagnosis of airway obstruction in the elderly: contribution of the SARA study" by Sorino et al in a recent issue of this journal.1 Being involved in the Global Initiative for Obstructive Lung Diseases (GOLD, it is nice to see the interest sparked by the GOLD strategy document. However, in the paper by Sorino et al, there are a few misunderstandings around GOLD and the fixed ratio (forced expiratory volume in 1 second/forced volume vital capacity < 0.70 that need clarification.View original paper by Sorino and colleagues.

  10. Thickness Dependence of Resistivity and Optical Reflectance of ITO Films

    Institute of Scientific and Technical Information of China (English)

    GAO Mei-Zhen; JOB R; XUE De-Sheng; FAHRNER W R

    2008-01-01

    @@ Indium-tin-oxide (ITO) films deposited on crystalline silicon wafer and Coming glass are prepared by directcurrent magnetron sputtering method at room temperature with various thicknesses. The thickness dependences of structure, resistance and optical reflectance of ITO films are characterized. The results show that when the film thickness is less than 4Ohm, the resistivity and optical reflectance of the ITO tilm changes remarkably with thickness. The optoelectrical properties trend to stabilize when the thickness is over 55 nm. The GXRD result implies that the ITO film begins to crystallize if only the thickness is large enough.

  11. Pixel Grafting: An Evolution of Mincing for Transplantation of Full-Thickness Wounds.

    Science.gov (United States)

    Singh, Mansher; Nuutila, Kristo; Kruse, Carla; Dermietzel, Alexander; Caterson, E J; Eriksson, Elof

    2016-01-01

    Split-thickness skin grafting is the gold standard for treatment of major skin loss. This technique is limited by donor-site availability in large burn injuries. With micrografting, a technique where split-thickness skin graft is minced into 0.8 × 0.8-mm pieces, the authors have demonstrated an expansion ratio of 1:100 and healing comparable to that achieved with split-thickness skin grafting. In this study, the authors explore the regenerative potential of a skin graft by cutting split-thickness skin grafts to pixel size (0.3 × 0.3 mm) grafts. Wound healing was studied in full-thickness wounds in a porcine model by creating an incubator-like microenvironment using polyurethane wound chambers. Multiple wound healing parameters were used to study the outcome of pixel grafting and compare it to micrografting and nontransplanted wounds. The authors' results show that 0.3 × 0.3-mm pixel grafts remain viable and contribute to skin regeneration. The pixel graft-transplanted wounds demonstrated a faster reepithelialization rate, decreased wound contraction, and increased mechanical stability compared with nontransplanted wounds. The reepithelialization rates of the wounds were significantly increased with pixel grafting at day 6 after wounding compared with micrografting. Among the other wound healing parameters, there were no significant differences between wounds transplanted with pixel grafts and micrografts. Pixel grafting technique would address the most commonly encountered limitations of the split-thickness skin graft with the possibility of an even larger expansion ratio than micrografting. This technique is simple and fast and can be conducted in the operating room or in the clinic.

  12. Mercury's lithospheric thickness and crustal density, as inferred from MESSENGER observations

    Science.gov (United States)

    James, P. B.; Mazarico, E.; Genova, A.; Smith, D. E.; Neumann, G. A.; Solomon, S. C.

    2015-12-01

    The gravity field and topography of Mercury measured by the MESSENGER spacecraft have provided insights into the thickness of the planet's elastic lithosphere, Te. We localized the HgM006 free-air gravity anomaly and gtmes_125v03 shape datasets to search for theoretical elastic thickness solutions that best fit a variety of localized coherence spectra between Bouguer gravity anomaly and topography. We adopted a crustal density of ρcrust =2700 kg m-3 for the Bouguer gravity correction, but density uncertainty did not markedly affect the elastic thickness estimates. A best-fit solution in the northern smooth plains (NSP) gives an elastic thickness of Te =30-60 km at the time of formation of topography for a range of ratios of top to bottom loading from 1 to 5. For a mechanical lithosphere with a thickness of ~2Te and a temperature of 1600 °C at the base, this solution is consistent with a geothermal gradient of 9-18 K km-1. A similar coherence analysis exterior to the NSP produces an elastic thickness estimate of Te =20-50 km, albeit with a poorer fit. Coherence in the northern hemisphere as a whole does not approach zero at any wavelength, because of the presence of variations in crustal thickness that are unassociated with elastic loading. The ratios and correlations of gravity and topography at intermediate wavelengths (harmonic degree l between 30 and 50) also constrain regional crustal densities. We localized gravity and topography with a moving Slepian taper and calculated regionally averaged crustal densities with the approximation ρcrust=Zl/(2πG), where Zl is the localized admittance and G is the gravitational constant. The only regional density estimates greater than 2000 kg m-3 for l=30 correspond to the NSP. Density estimates outside of the NSP were unreasonably low, even for highly porous crust. We attribute these low densities to the confounding effects of crustal thickness variations and Kaula filtering of the gravity dataset at the highest harmonic

  13. Thick or Thin Ice Shell on Europa?

    Science.gov (United States)

    2007-01-01

    Scientists are all but certain that Europa has an ocean underneath its icy surface, but they do not know how thick this ice might be. This artist concept illustrates two possible cut-away views through Europa's ice shell. In both, heat escapes, possibly volcanically, from Europa's rocky mantle and is carried upward by buoyant oceanic currents. If the heat from below is intense and the ice shell is thin enough (left), the ice shell can directly melt, causing what are called 'chaos' on Europa, regions of what appear to be broken, rotated and tilted ice blocks. On the other hand, if the ice shell is sufficiently thick (right), the less intense interior heat will be transferred to the warmer ice at the bottom of the shell, and additional heat is generated by tidal squeezing of the warmer ice. This warmer ice will slowly rise, flowing as glaciers do on Earth, and the slow but steady motion may also disrupt the extremely cold, brittle ice at the surface. Europa is no larger than Earth's moon, and its internal heating stems from its eccentric orbit about Jupiter, seen in the distance. As tides raised by Jupiter in Europa's ocean rise and fall, they may cause cracking, additional heating and even venting of water vapor into the airless sky above Europa's icy surface. (Artwork by Michael Carroll.)

  14. Thin, thick and dark discs in LCDM

    CERN Document Server

    Read, J I; Agertz, O; Debattista, Victor P

    2008-01-01

    In a LCDM cosmology, the Milky Way accretes satellites into the stellar disc. We use cosmological simulations to assess the frequency of near disc plane and higher inclination accretion events, and collisionless simulations of satellite mergers to quantify the final state of the accreted material and the effect on the thin disc. On average, a Milky Way-sized galaxy has 1.5 subhalos with vmax>80km/s; 5 with vmax>60km/s; and 13 with vmax>40km/s merge at redshift z>1. A third of these merge at an impact angle 20 degrees) are twice as likely as low inclination ones. These lead to structures that closely resemble the recently discovered inner/outer stellar halos. They also do more damage to the Milky Way stellar disc creating a more pronounced flare, and warp; both long-lived and consistent with current observations. The most massive mergers (vmax > 80km/s) heat t he thin disc enough to produce a thick disc. These heated thin disc stars are essential for obtaining a thick disc as massive as that seen in the Milky ...

  15. Modular assembly of thick multifunctional cardiac patches

    Science.gov (United States)

    Fleischer, Sharon; Shapira, Assaf; Feiner, Ron; Dvir, Tal

    2017-01-01

    In cardiac tissue engineering cells are seeded within porous biomaterial scaffolds to create functional cardiac patches. Here, we report on a bottom-up approach to assemble a modular tissue consisting of multiple layers with distinct structures and functions. Albumin electrospun fiber scaffolds were laser-patterned to create microgrooves for engineering aligned cardiac tissues exhibiting anisotropic electrical signal propagation. Microchannels were patterned within the scaffolds and seeded with endothelial cells to form closed lumens. Moreover, cage-like structures were patterned within the scaffolds and accommodated poly(lactic-co-glycolic acid) (PLGA) microparticulate systems that controlled the release of VEGF, which promotes vascularization, or dexamethasone, an anti-inflammatory agent. The structure, morphology, and function of each layer were characterized, and the tissue layers were grown separately in their optimal conditions. Before transplantation the tissue and microparticulate layers were integrated by an ECM-based biological glue to form thick 3D cardiac patches. Finally, the patches were transplanted in rats, and their vascularization was assessed. Because of the simple modularity of this approach, we believe that it could be used in the future to assemble other multicellular, thick, 3D, functional tissues. PMID:28167795

  16. Peripapillary choroidal thickness in healthy Turkish subjects

    Directory of Open Access Journals (Sweden)

    Erbagci H

    2015-07-01

    Full Text Available Hulya Erbagci,1 Burak Oren,2 Seydi Okumus,3 Serhat Kenan,3 Pelin Celemler,3 Ibrahim Erbagci3 1Department of Anatomy, Medical Faculty, Zirve University Emine Bahattin Nakiboglu, Gaziantep, 2Department of Ophthalmology, Kilis State Hospital, Kilis, 3Department of Ophthalmology, Faculty of Medicine, University of Gaziantep, Gaziantep, Turkey Aim: The objective of the study reported here was to investigate the normal peripapillary choroidal thickness (CT, measured by enhanced depth imaging optical coherence tomography (EDI-OCT, in healthy Turkish volunteers. Materials and methods: In this prospective cross-sectional study, 57 eyes of 57 healthy Turkish subjects were enrolled. Each participant underwent a comprehensive ophthalmic examination and peripapillary CT measurement using EDI-OCT. Results: The mean age of the 25 female and 32 male patients in the study was 30.9±10.6 years (range, 18–56 years. The mean peripapillary CT at the superior, inferior, nasal, and temporal sites was 225±57, 183±47, 220±57, and 233±59 µm, respectively. The inferior peripapillary CT value was significantly lower than the peripapillary CT values (P<0.001 for all, whereas no significant differences were found between the superior, nasal, and temporal peripapillary CT values. Conclusion: The findings of the study revealed that Turkish people had significantly lower peripapillary CT values in the inferior quadrant than in the superior, nasal, and temporal quadrants. Keywords: peripapillary choroidal thickness, enhanced depth imaging optical coherence tomography, EDI-OCT

  17. Formation of thick dielectrophoretic carbon nanotube fibers

    Energy Technology Data Exchange (ETDEWEB)

    Plaado, Margo; Mononen, Robert Matias; Lohmus, Ruenno; Kink, Ilmar; Saal, Kristjan, E-mail: saal@fi.tartu.ee [Institute of Physics, University of Tartu, and Estonian Nanotechnology Competence Centre, 142 Riia Street, 51014 Tartu (Estonia)

    2011-07-29

    The aim of this work was to study the formation process of dielectrophoretic (DEP) carbon nanotube fibers (CNT-fibers) and characterize the fiber properties relevant to their technological applications. The fiber diameter was shown to increase when applied voltage was increased (up to 350 V{sub pp}) and when retraction speed was decreased (down from 400 {mu}m s{sup -1}) in accordance with theoretical expectations. This paper represents the first demonstration of the formation of thick DEP CNT-fibers (up to {approx} 0.4 mm). This is an intriguing result, as it expands the diversity of possible applications of the fibers and facilitates their characterization by analytical methods that require large quantities of the material. The performance of these thick fibers was as follows: a density of {approx} 0.35 g cm{sup -3}, a tensile strength of {approx} 15 MPa, a Young's modulus of {approx} 1 GPa, and an electrical resistivity of {approx} 70 m{Omega} cm.

  18. Bilayer Thickness Mismatch Controls Domain Size in Model Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Heberle, Frederick A [ORNL; Petruzielo, Robin S [ORNL; Pan, Jianjun [ORNL; Drazba, Paul [ORNL; Kucerka, Norbert [Canadian Neutron Beam Centre and Comelius University (Slovakia); Feigenson, Gerald [Cornell University; Katsaras, John [ORNL

    2013-01-01

    The observation of lateral phase separation in lipid bilayers has received considerable attention, especially in connection to lipid raft phenomena in cells. It is widely accepted that rafts play a central role in cellular processes, notably signal transduction. While micrometer-sized domains are observed with some model membrane mixtures, rafts much smaller than 100 nm beyond the reach of optical microscopy are now thought to exist, both in vitro and in vivo. We have used small-angle neutron scattering, a probe free technique, to measure the size of nanoscopic membrane domains in unilamellar vesicles with unprecedented accuracy. These experiments were performed using a four-component model system containing fixed proportions of cholesterol and the saturated phospholipid 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), mixed with varying amounts of the unsaturated phospholipids 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dioleoylsn- glycero-3-phosphocholine (DOPC). We find that liquid domain size increases with the extent of acyl chain unsaturation (DOPC:POPC ratio). Furthermore, we find a direct correlation between domain size and the mismatch in bilayer thickness of the coexisting liquid-ordered and liquid-disordered phases, suggesting a dominant role for line tension in controlling domain size. While this result is expected from line tension theories, we provide the first experimental verification in free-floating bilayers. Importantly, we also find that changes in bilayer thickness, which accompany changes in the degree of lipid chain unsaturation, are entirely confined to the disordered phase. Together, these results suggest how the size of functional domains in homeothermic cells may be regulated through changes in lipid composition.

  19. Thick SU-8 photolithography for BioMEMS

    Science.gov (United States)

    Rabarot, Marc; Bablet, Jacqueline; Ruty, Marine; Kipp, Matthieu; Chartier, Isabelle; Dubarry, Christophe

    2003-01-01

    SU-8, negative-tone epoxy base, photoresist has a great potential for ultra-thick high aspect ratio structures in low cost micro-fabrication technologies. Commercial formulation of NanoTM SU-8 2075 is investigate, process limitations are discuss. Good layer uniformity (few %) for single layer up to 200 μm could be obtained in a covered RC8 (Suss-MicroTec) spin coater, but for ultra-thick microstructures it is also possible to cast on the wafer a volume controlled of resist up to 1.5 mm without barrier. Long baking times are necessary for a well process control. The layout of the photo-masks design and process parameters have great impact on residual stress effects and adhesion failures, especially for dense SU-8 patterns on metallic under layer deposited on silicon wafers. A specific treatment applied before the resist coating definitely solved this problem. Bio-fluidic applications of on-wafer direct prototyping (silicon, glass, plastics) are presented. An example will be given on prototyping dielectophorectic micro-cell manipulation component. The SU-8 fluidic structure is made by a self planarized multi-level process (application for 2,5 to 3D microstructures). Biotechnology applications of integrated micro-cells could be considered thanks to the SU-8 good resistance to PCR (Polymerase Chain Reaction). Future developments are focusing on the SU-8 capabilities for Deep Reactive Ion Etching of plastic and 3D shaping of microstructures using a process called : Multidirectional Inclined Exposure Lithography (MIEL).

  20. Predicting the Mean Liquid Film Thickness and Profile along the Annular Length of a Uniformly Heated Channel at Dryout

    Directory of Open Access Journals (Sweden)

    V.Y. Agbodemegbe

    2011-03-01

    Full Text Available The objective of this study was to predict the mean liquid film thickness and profile at high shear stress using a mechanistic approach. Knowledge of the liquid film thickness and its variation with two-phase flow parameters is critical for the estimation of safety parameters in the annular flow regime. The mean liquid film thickness and profile were predicted by the PLIFT code designed in Fortran 95 programming language using the PLATO FTN95 compiler. The film thickness was predicted within the annular flow regime for a flow boiling quality ranging from 40 to 80 % at high interfacial shear stress. Results obtained for a laminar liquid film flow were dumped into an excel file when the ratio of the actual predicted film thickness to the critical liquid film thickness lied within the range of 0.9 to unity. The film thickness was observed to decrease towards the exit of the annular regime at high flow boiling qualities and void fractions. The observation confirmed the effect of evaporation in decreasing the film thickness as quality is increased towards the exit of the annular regime.

  1. Contact ratio and deformation of asperity in nano-partia lubrication

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Partial lubrication or mixed lubrication in the nano-scale is discussed, which is consti-tuted from dry contact, boundary lubrication, thin film lubrication. A dynamic contact ratio has beenused to describe such lubrication, and the relationship between the contact ratio and its influencefactors was investigated. Experimental results indicate that the dynamic contact ratio increaseswith the decrease of film thickness by the exponential function. The decrease of speed and lubri-cant viscosity, and the increase of loads will enlarge the value of the contact ratio. When the polaradditives are added into the basic oil, the contact ratio decreases. In addition, the contact ratio ofthe surfaces with small roughness is larger than that of the surfaces with large roughness at verylow speed. However, the contact ratio of smooth surfaces decreases more quickly with speed thanthat of rough surfaces, and therefore, it will become smaller than that of rough surfaces after speedincreases over a certain degree.

  2. Impact of polymer film thickness and cavity size on polymer flow during embossing : towards process design rules for nanoimprint lithography.

    Energy Technology Data Exchange (ETDEWEB)

    Schunk, Peter Randall; King, William P. (Georgia Institute of Technology, Atlanta, GA); Sun, Amy Cha-Tien; Rowland, Harry D. (Georgia Institute of Technology, Atlanta, GA)

    2006-08-01

    This paper presents continuum simulations of polymer flow during nanoimprint lithography (NIL). The simulations capture the underlying physics of polymer flow from the nanometer to millimeter length scale and examine geometry and thermophysical process quantities affecting cavity filling. Variations in embossing tool geometry and polymer film thickness during viscous flow distinguish different flow driving mechanisms. Three parameters can predict polymer deformation mode: cavity width to polymer thickness ratio, polymer supply ratio, and Capillary number. The ratio of cavity width to initial polymer film thickness determines vertically or laterally dominant deformation. The ratio of indenter width to residual film thickness measures polymer supply beneath the indenter which determines Stokes or squeeze flow. The local geometry ratios can predict a fill time based on laminar flow between plates, Stokes flow, or squeeze flow. Characteristic NIL capillary number based on geometry-dependent fill time distinguishes between capillary or viscous driven flows. The three parameters predict filling modes observed in published studies of NIL deformation over nanometer to millimeter length scales. The work seeks to establish process design rules for NIL and to provide tools for the rational design of NIL master templates, resist polymers, and process parameters.

  3. Caving thickness effects of surrounding rocks macro stress shell evolving characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Guang-xiang Xie; Ke Yang [Anhui University of Science and Technology, Huainan (China). Key Laboratory of Coal Mine Safety and Efficiently Caving of Ministry of Education

    2009-06-15

    In order to explore the influence of different caving thicknesses on the macro stress shell, (MSS) distribution and evolving characteristics of surrounding rocks in unsymmetrical disposal and fully mechanized top-coal caving (FMTC), based on unsymmetrical disposal characteristics, the analyses of numerical simulation, material simulation and in-situ observation were synthetically applied according to the geological and technical conditions of the 1151(3) working face in Xieqiao Mine. The results show that the stress peak value of the MSS-base and the ratio of MSS-body height to caving thickness are nonlinear and inversely proportional to the caving thickness. The MSS-base width, the MSS-body height, the MSS-base distance to working face wall and the rise distance of MSS-base beside coal pillar are nonlinear and directly proportional to the caving thickness. The characteristics of MSS distribution and its evolving rules of surrounding rocks and the integrated caving thickness effects are obtained. The investigations will provide theoretic references to the surrounding rocks stability control of the working face and roadway, roadway layout, gas extraction and exploitation, and efficiency of caving, etc. 13 refs., 5 figs., 5 tabs.

  4. Thickness Considerations of Two-Dimensional Layered Semiconductors for Transistor Applications

    Science.gov (United States)

    Zhang, Youwei; Li, Hui; Wang, Haomin; Xie, Hong; Liu, Ran; Zhang, Shi-Li; Qiu, Zhi-Jun

    2016-07-01

    Layered two-dimensional semiconductors have attracted tremendous attention owing to their demonstrated excellent transistor switching characteristics with a large ratio of on-state to off-state current, Ion/Ioff. However, the depletion-mode nature of the transistors sets a limit on the thickness of the layered semiconductor films primarily determined by a given Ion/Ioff as an acceptable specification. Identifying the optimum thickness range is of significance for material synthesis and device fabrication. Here, we systematically investigate the thickness-dependent switching behavior of transistors with a wide thickness range of multilayer-MoS2 films. A difference in Ion/Ioff by several orders of magnitude is observed when the film thickness, t, approaches a critical depletion width. The decrease in Ion/Ioff is exponential for t between 20 nm and 100 nm, by a factor of 10 for each additional 10 nm. For t larger than 100 nm, Ion/Ioff approaches unity. Simulation using technical computer-aided tools established for silicon technology faithfully reproduces the experimentally determined scaling behavior of Ion/Ioff with t. This excellent agreement confirms that multilayer-MoS2 films can be approximated as a homogeneous semiconductor with high surface conductivity that tends to deteriorate Ion/Ioff. Our findings are helpful in guiding material synthesis and designing advanced field-effect transistors based on the layered semiconductors.

  5. Caving thickness effects of surrounding rocks macro stress shell evolving characteristics

    Institute of Scientific and Technical Information of China (English)

    XIE Guang-xiang; YANG Ke

    2009-01-01

    In order to explore the influence of different caving thicknesses on the MSS dis-tribution and evolving characteristics of surrounding rocks in unsymmetrical disposal and fully mechanized top-coal caving (FMTC), based on unsymmetrical disposal characteris-tics, the analyses of numerical simulation, material simulation and in-situ observation were synthetically applied according to the geological and technical conditions of the 1151(3) working face in Xieqiao Mine. The results show that the stress peak value of the MSS-base and the ratio of MSS-body height to caving thickness are nonlinear and inversely proportional to the caving thickness. The MSS-base width, the MSS-body height, the MSS-base distance to working face wall and the rise distance of MSS-base beside coal pillar are nonlinear and directly proportional to the caving thickness. The characteristics of MSS distribution and its evolving rules of surrounding rocks and the integrated caving thickness effects are obtained. The investigations will provide lots of theoretic references to the surrounding rocks' stability control of the working face and roadway, roadway layout, gas extraction and exploitation, and efficiency of caving, etc.

  6. Effect of specimen thickness on Mode Ⅱ fracture toughness of rock

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Anti-symmetric four-point bending specimens with different thickness, without and with guiding grooves, were used to conduct Mode Ⅱ fracture test and study the effect of specimen thickness on Mode Ⅱ fracture toughness of rock. Numerical calculations show that the occurrence of Mode Ⅱ fracture in the specimens without guiding grooves (when the inner and outer loading points are moved close to the notch plane) and with guiding grooves is attributed to a favorable stress condition created for Mode Ⅱ fracture, i.e. tensile stress at the notch tip is depressed to be lower than the tensile strength or to be compressive stress, and the ratio of shear stress to tensile stress at notch tip is very high. The measured value of Mode Ⅱ fracture toughness KⅡC decreases with the increase of the specimen thickness or the net thickness of specimen. This is because a thick specimen promotes a plane strain state and thus results in a relatively small fracture toughness.

  7. Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

    Science.gov (United States)

    Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

    2016-05-01

    Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

  8. Plasmonic finite-thickness metal-semiconductor-metal waveguide as ultra-compact modulator

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Malureanu, Radu; Lavrinenko, Andrei

    2013-01-01

    electrical control of signal propagation. By pumping the core we can vary the gain level and thus the transmittance of the whole system. The study of the device was made using both analytical approaches for planar two-dimensional case as well as numerical simulations for finite-width waveguides. We analyze...... the eigenmodes of the F-MSM waveguide, propagation constant, confinement factor, Purcell factor, absorption coefficient, and extinction ratio of the structure. We show that using thin metal layers instead of thick ones we can obtain higher extinction ratio of the device....

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

    DEFF Research Database (Denmark)

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

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

  10. Saturated thickness of the Madison aquifer, Black Hills, South Dakota.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a polygon coverage created in ARC/INFO that represents the saturated thickness of the Madison aquifer, which includes the entire thickness of the...

  11. 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.

  12. Weather-Corrected Performance Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Dierauf, T.; Growitz, A.; Kurtz, S.; Cruz, J. L. B.; Riley, E.; Hansen, C.

    2013-04-01

    Photovoltaic (PV) system performance depends on both the quality of the system and the weather. One simple way to communicate the system performance is to use the performance ratio (PR): the ratio of the electricity generated to the electricity that would have been generated if the plant consistently converted sunlight to electricity at the level expected from the DC nameplate rating. The annual system yield for flat-plate PV systems is estimated by the product of the annual insolation in the plane of the array, the nameplate rating of the system, and the PR, which provides an attractive way to estimate expected annual system yield. Unfortunately, the PR is, again, a function of both the PV system efficiency and the weather. If the PR is measured during the winter or during the summer, substantially different values may be obtained, making this metric insufficient to use as the basis for a performance guarantee when precise confidence intervals are required. This technical report defines a way to modify the PR calculation to neutralize biases that may be introduced by variations in the weather, while still reporting a PR that reflects the annual PR at that site given the project design and the project weather file. This resulting weather-corrected PR gives more consistent results throughout the year, enabling its use as a metric for performance guarantees while still retaining the familiarity this metric brings to the industry and the value of its use in predicting actual annual system yield. A testing protocol is also presented to illustrate the use of this new metric with the intent of providing a reference starting point for contractual content.

  13. Impact of Scaling Gate Insulator Thickness on the Performance of Carbon Nanotube Field Effect Transistors (CNTFETs

    Directory of Open Access Journals (Sweden)

    Devi Dass

    2013-05-01

    Full Text Available As scaling down Si MOSFET devices degrade device performance in terms of short channel effects. Carbon nanotube field effect transistor (CNTFET is one of the novel nanoelectronics devices that overcome those MOSFET limitations. The carbon nanotube field effect transistors (CNTFETs have been explored and proposed to be the promising candidate for the next generation of integrated circuit (IC devices. To explore the role of CNTFETs in future integrated circuits, it is important to evaluate their performance. However, to do that we need a model that can accurately describe the behavior of the CNTFETs so that the design and evaluation of circuits using these devices can be made. In this paper, we have investigated the effect of scaling gate insulator thickness on the device performance of cylindrical shaped ballistic CNTFET in terms of transfer characteristics, output characteristics, average velocity, gm/Id ratio, mobile charge, quantum capacitance/insulator capacitance, drive current (Ion, Ion / Ioff ratio, transconductance, and output conductance. We concluded that the device metrics such as Ion, Ion / Ioff ratio, transconductance, and output conductance increases with the decrease in gate insulator thickness. Also, we concluded that the gate insulator thickness reduction causes subthreshold slope close to the theoretical limit of 60 mV/decade and DIBL close to zero at room temperature.

  14. GALAH Survey: Chemically Tagging the Thick Disk

    CERN Document Server

    Bland-Hawthorn, J; Freeman, K

    2015-01-01

    The GALAH survey targets one million stars in the southern hemisphere down to a limiting magnitude of V = 14 at the Anglo- Australian Telescope. The project aims to measure up to 30 elemental abundances and radial velocities (~1 km/s accuracy) for each star at a resolution of R = 28000. These elements fall into 8 independent groups (e.g. alpha, Fe peak, r-process). For all stars, Gaia will provide distances to 1% and transverse velocities to 1 km/s or better, giving us a 14D set of parameters for each star, i.e. 6D phase space and 8D abundance space. There are many scientic applications but here we focus on the prospect of chemically tagging the thick disk and making a direct measurement of how stellar migration evolves with cosmic time.

  15. Crustal thickness controlled by plate tectonics

    DEFF Research Database (Denmark)

    Artemieva, Irina M.; Meissner, Rolf

    2012-01-01

    The continental crust on Earth cannot be extracted directly from the mantle, and the primary crust extracted directly from an early magma ocean is not preserved on Earth. We review geophysical and geochemical aspects of global crust–mantle material exchange processes and examine the processes which...... magmatism. While both subduction and delamination recycle crustal material into the mantle, mafic magmatism transports mantle material upward and participates in growth of newoceanic and continental crusts and significant structural and chemicalmodification of the latter. We discuss the role of basalt....../gabbro–eclogite phase transition in crustal evolution and the links between lithosphere recycling, mafic magmatism, and crustal underplating. We advocate that plate tectonics processes, togetherwith basalt/gabbro–eclogite transition, limit crustal thickness worldwide by providing effective mechanisms of crustal...

  16. 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.

  17. Engineering thick tissues - the vascularisation problem

    Directory of Open Access Journals (Sweden)

    H C H Ko

    2007-07-01

    Full Text Available The ability to create thick tissues is a major tissue engineering challenge, requiring the development of a suitable vascular supply. Current trends are seeing the utilization of cells seeded into hybrid matrix/scaffold systems to create in vitro vascular analogues. Approaches that aim to create vasculature in vitro include the use of biological extracellular matrices such as collagen hydrogels, porous biodegradable polymeric scaffolds with macro- and micro-lumens and micro-channels, co-culture of cells, incorporation of growth factors, culture in dynamic bioreactor environments, and combinations of these. Of particular interest are those approaches that aim to create bioengineered tissues in vitro that can be readily connected to the host's vasculature following implantation in order to maintain cell viability.

  18. Tensile Instability in a Thick Elastic Body

    Science.gov (United States)

    Overvelde, Johannes T. B.; Dykstra, David M. J.; de Rooij, Rijk; Weaver, James; Bertoldi, Katia

    2016-08-01

    A range of instabilities can occur in soft bodies that undergo large deformation. While most of them arise under compressive forces, it has previously been shown analytically that a tensile instability can occur in an elastic block subjected to equitriaxial tension. Guided by this result, we conducted centimeter-scale experiments on thick elastomeric samples under generalized plane strain conditions and observed for the first time this elastic tensile instability. We found that equibiaxial stretching leads to the formation of a wavy pattern, as regions of the sample alternatively flatten and extend in the out-of-plane direction. Our work uncovers a new type of instability that can be triggered in elastic bodies, enlarging the design space for smart structures that harness instabilities to enhance their functionality.

  19. Radioactive waste disposal in thick unsaturated zones.

    Science.gov (United States)

    Winogard, I J

    1981-06-26

    Portions of the Great Basin are undergoing crustal extension and have unsaturated zones as much as 600 meters thick. These areas contain multiple natural barriers capable of isolating solidified toxic wastes from the biosphere for tens of thousands to perhaps hundreds of thousands of years. An example of the potential utilization of such arid zone environments for toxic waste isolatic is the burial of transuranic radioactive wastes at relatively shallow depths (15 to 100 meters) in Sedan Crater, Yucca Flat, Nevada. The volume of this man-made crater is several times that of the projected volume of such wastes to the year 2000. Disposal in Sedan Crater could be accomplished at a savings on the order of $0.5 billion, in comparison with current schemes for burial of such wastes in mined repositories at depths of 600 to 900 meters, and with an apparently equal likelihood of waste isolation from the biosphere.

  20. The control of overburden thickness on resurgent domes: insights from analogue models

    Science.gov (United States)

    Acocella, V.; Cifelli, F.; Funiciello, R.

    2001-11-01

    Resurgent doming consists of the uplift, usually accompanied by volcanic activity, of part of a collapse caldera. Analogue models were used to investigate the architecture of resurgent domes. Dry sand simulates the brittle crust; uprising silicone, located at the base of the sand-pack, simulates magma. The deformation pattern depends mainly upon: (1) the ratio (aspect ratio) between the thickness of the sand overburden and the width of the silicone intrusion; (2) the duration of experiment. For aspect ratios ≈1, two concentric domes develop; the first-formed outer dome is bordered by inward-dipping reverse ring faults, while the inner dome by outward-dipping normal ring faults. The layers inside the dome are uniformly dipping. For aspect ratios ≈0.4, the dome shows a crestal depression, surrounded by radial fractures, followed by an apical extrusion of silicone. The internal structure of the dome is made up of domed layers. Independently from the aspect ratio, the duration of the experiment enhances silicone extrusion. A consistent structure is observed in most resurgent domes in nature. The comparison between experiments and nature suggests that two distinct resurgence modes occur, mainly depending on the aspect ratio (thickness/width) of the crust overlying the magma chamber. Aspect ratios ≈1 develop a resurgent block with uniformly-dipping layers and peripheral volcanic activity (Ischia and Pantelleria type). Aspect ratios ≈0.4 develop a resurgent dome with a crestal depression, domed layers within and peripheral and internal volcanic activity (Valles and Long Valley type).

  1. Measurement Method of the Thickness Uniformity for Polymer Films

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Several methods for investigating the thickness uniformity of polymer thin films are presented as well as their measurement principles. A comparison of these experimental methods is given.The cylindrical lightwave reflection method is found to can obtain the thickness distribution along a certain direction.It is a simple and suitable method to evaluate the film thickness uniformity.

  2. ASYMPTOTIC ANALYSIS OF LINEARLY ELASTIC SHALLOW SHELLS WITH VARIABLE THICKNESS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The author considers a linearly elastic shallow shell with variable thickness and shows that, as the thickness of the shell goes to zero, the solution of the three-dimensional equations converges to the solution of the two-dimensional shallow shell equations with variable thickness.

  3. Thick Translation as a New Trend of Translation Studies

    Institute of Scientific and Technical Information of China (English)

    饶莉

    2016-01-01

    This paper, based on the development and history of thick translation, is intended to carry out a comparative critic of the interpretations of“thick translation”proposed by different scholars so as to explore the profound meanings and significance of“thick translation”as a new strategy, which has reflected and predicted the new trend of translation studies.

  4. 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.

  5. Mapping sediment thickness of Islamabad city using empirical relationships: Implications for seismic hazard assessment

    Indian Academy of Sciences (India)

    Sarfraz Khan; M Asif Khan

    2016-04-01

    Soft sediments make an important component of the subsurface lithology, especially in areas underlain by river/stream basins. Occupying a position directly above the bedrock up to the land surface, these soft sediments can range in thickness from few centimeters to hundreds of meters. They carry a specialnuisance in seismic hazards, as they serve as a source of seismic amplification that may enhance the seismic shaking of many folds. Determination of the thickness of the soft sediments is therefore crucial in seismic hazard analysis. A number of studies in recent years have demonstrated that frequency andamplitude spectrum obtained from the noise measurements during the recording of natural seismicitycan be used to obtain thickness of soft sediments covering the bedrock. Nakamura (1989) presented atechnique to determine such spectrum using ratio of horizontal to vertical components of the Rayleighwaves. The present study is based on an extensive set of microtremor measurements carried out in theIslamabad city, Pakistan. Fundamental frequencies were obtained from weak motion sensors and TrominoEngy Plus instruments to show that the correlation is clearly valid for a wide range of sediment thickness.A simple formula was derived for the investigated area to determine directly the thickness of sedimentsfrom the main peaks in the H/V spectrum for seismometer and Tromino data separately. A comparisonis made between sediment thicknesses derived from empirical relations developed in this study withthose given in literature to demonstrate a positive correlation. The correlation of instrumental resonantfrequencies with calculated resonant frequencies (theoretical) suggests that the relation derived from thenoise measurements mostly depends on the velocity depth function of the shear wave. The fundamentalfrequency of the main peak of spectral ratio of H/V using the both instruments correlates well withthe thickness of sediments at the site obtained from the borehole data. It

  6. Quantitative assessment of macular thickness in normal subjects and patients with diabetic retinopathy by scanning retinal thickness analyser

    OpenAIRE

    Oshima, Y.; Emi, K.; Yamanishi, S.; Motokura, M.

    1999-01-01

    AIMS—To evaluate the scanning retinal thickness analyser (RTA), a novel non-invasive imaging instrument, in diagnosing and quantitatively characterising diabetic macular oedema, and to investigate the relation between central macula thickness measured by RTA and other clinical examinations.
METHODS—Central macular thickness was measured using the RTA in 40 normal subjects and 60 patients with diabetic retinopathy. The reproducibility of the retinal thickness measurements was evaluated by calc...

  7. Thickness Evaluation of Aluminium Plate Using Pulsed Eddy Current Technique

    Science.gov (United States)

    Singh, Gurpartap; Bapat, Harsh Madhukar; Singh, Bhanu Pratap; Bandyopadhyay, Manojit; Puri, Rakesh Kumar; Badodkar, Deepak Narayanrao

    2013-10-01

    This paper describes a pulsed eddy current (PEC) based non-destructive testing system used for detection of thickness variation in aluminium plate. A giant magneto-resistive sensor has been used instead of pick up coil for detecting resultant magnetic field. The PEC response signals obtained from 1 to 5 mm thickness change in aluminium plate were investigated. Two time domain features, namely peak value and time to peak, of PEC response were used for extracting information about thickness variation in aluminium plate. The variation of peak value and time to peak with thickness was compared. A program was developed to display the thickness variation of the tested sample.

  8. CT quality assurance: computer assisted slice thickness determination.

    Science.gov (United States)

    Schneiders, N J; Bushong, S C

    1980-01-01

    The precise slice geometry of a CT scanner is an important, albeit tedious to determine, characteristic. A series of computer programs have been developed to analyze the slice thickness insert of the AAPM phantom. Without operator assistance they generate the beam profiles and slice thicknesses at three points in the scan field. A representative analysis is done on an AS&E scanner with slice thickness settings of 2 to 10 mm. The resulting discrepent measured thicknesses, ranging from 3 to 8 mm, indicate the need to perform such slice thickness measurements as part of a regular quality assurance program.

  9. Variations of the crustal thickness in the Betic-Rif domain and their foreland regions, by P-Receiver Functions

    Science.gov (United States)

    Stich, D.; Mancilla, F.; Morales, J.; Martin, R.; Diaz, J.; Pazos, A.; Cordoba, D.; Pulgar, J. A.; Ibarra, P.; Harnafi, M.; Gonzalez-Lodeiro, F.

    2012-12-01

    To image the crustal structure of the Betic-Rif Range and the surrounding area we perform a P-receiver function study (PRF). We calculate PRFs at 110 broadband stations located in South Iberia Peninsula and North Morocco to obtain thickness and average Vp/Vs ratio for the Crust. The Crustal thickness values show strong lateral variations throughout the region. Crustal thicknesses vary between ~19 km and ~46 km. The Betic and Rif ranges are underlined by a thickened crust with crustal thicknesses between ~35 km and ~46 km, reaching the highest values in the contact between the Alboran Domain and External Zones. Southeast Iberia and Northeast Morocco are affected by significant crustal thinning, with crustal thicknesses ranging from ~19 km to ~30 km, with the shallowest Moho along the Mediterranean coast. The transition from thick to thin crust is coincident with the faults system of the Trans-Alboran Shear Zone. Toward the North, the Iberian Massif is an homogeneous domain of average 30-31 km crustal thickness and flat Moho discontinuity with low average Vp/Vs ratios ~1.72. Further south an extended domain, which includes the Atlas domain and its foreland regions, presents crustal thickness of 27-34km. Vp/Vs ratios in north Morocco show normal values of ~1.75 for most stations except for the Atlas domain, where several stations present low Vp/Vs ratios around 1.71. The obtained PRFs are migrated to depth building cross-section images to delineate the crustal mantle discontinuity (Moho) along the study area. In the migrated images, we include altogether ~11.200 PFRs to follow the Moho discontinuity from the Iberian Massif, in the North, along the Gribraltar arc towards the Moroccan Massif in the South. These images show how, in the North, the Iberian crust underthrust the Alboran domain along their contact with the observation of a slab, from the western limit until the 3°W longitude, reaching the maximum depth of ~70 km under the coast coincide with the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-02-01

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

  11. Compton Thick AGN in the XMM-COSMOS survey

    CERN Document Server

    Lanzuisi, G; Georgantopoulos, I; Georgakakis, A; Delvecchio, I; Akylas, T; Berta, S; Bongiorno, A; Brusa, M; Cappelluti, N; Civano, F; Comastri, A; Gilli, R; Gruppioni, C; Hasinger, G; Iwasawa, K; Koekemoer, A; Lusso, E; Marchesi, S; Mainieri, V; Merloni, A; Mignoli, M; Piconcelli, E; Pozzi, F; Rosario, D J; Salvato, M; Silverman, J; Trakhtenbrot, B; Vignali, C; Zamorani, G

    2014-01-01

    Heavily obscured, Compton Thick (CT, NH>10^24 cm-2) AGN may represent an important phase in AGN/galaxy co-evolution and are expected to provide a significant contribution to the cosmic X-ray background (CXB) at its peak. Through direct X-ray spectra analysis, we selected 39 heavily obscured AGN (NH>3x10^23 cm-2) in the 2 deg^2 XMM-COSMOS survey. Thanks to deeper Chandra data available in the field, we can define 10 of these sources as bona-fide CT, spanning a large range of redshift and luminosity, and estimate the efficiency of our selection to be of the order of 80%. We collected the multi-wavelength information available for these sources, to study the distribution of BH mass (MBH), Eddington ratio (lambda_Edd), stellar mass (M*), specific star formation rate (sSFR) in comparison with a sample of unobscured AGN. We find that highly obscured sources tend to have significantly smaller MBH and higher lambda_Edd with respect to unobscured sources. The sSFR of highly obscured sources is consistent with the one ...

  12. Film-thickness Error Analysis of Optical Disk Systems

    Institute of Scientific and Technical Information of China (English)

    WANG Yang; GU Donghong; GAN Fuxi

    2001-01-01

    It is difficult to exactly control the film thickness of optical disk multilayer in the actual coating process. The thickness error becomes a main factor affecting the optical characters of the film system. The thickness error′s sensitivity factor of dielectric optical multilayer is derived from the optical matrix in this paper. The effect of the thickness error on the reflectivity or reflectivity contrast of the optical disk multilayer is analyzed with a numerical calculation. The sensitivities to thickness error for different layers or in different film-thickness ranges are compared and discussed. A sketchy method defining allowable thickness error is given. Some experimental results verify the applicability of our theoretical analysis.

  13. Oriented Growth of PZT thick film embedded with PZT nanoparticles

    Institute of Scientific and Technical Information of China (English)

    DUAN Zhong-xia; YUAN Jie; ZHAO Quan-liang; LU Ran; CAO Mao-sheng

    2009-01-01

    This paper reports that dense and crack-free (100) oriented lead zirconate titanate (Pb(Zr0.52Ti0.48)O3,PZT) thick film embedded with PZT nanoparticles has been successfully fabricated on Pt/Cr/SiO2/Si substrate by using PT transition layer and PVP additive. The thick film possesses single-phase perovskite structure and perfectly (100) oriented. The (100) orientation degree of the PZT films strongly depended on annealing time and for the 4 μm-thick PZT film which was annealed at 700 ℃ for 5 min is the largest. The (100) orientation degree of the PZT thick film gradually strengthen along with the thickness of film decreasing. The 3 μm-thick PZT thick film which was annealed at 700 ℃ for 5 min has the strongest (100) orientation degree, which is 82. 3%.

  14. Effect of airfoil (trailing-edge) thickness on the numerical solution of panel methods based on the Dirichlet boundary condition

    Science.gov (United States)

    Yon, Steven; Katz, Joseph; Plotkin, Allen

    1992-01-01

    The practical limit of airfoil thickness ratio for which acceptable engineering results are obtainable with the Dirichlet boundary-condition-based numerical methods is investigated. This is done by studying the effect of thickness on the calculated pressure distribution near the trailing edge and by comparing the aerodynamic coefficients with available exact solutions. The first objective of this study, owing to the wide use of such computational methods, is to demonstrate the numerical symptoms that occur when the body or wing thickness approaches zero and to increase the awareness of potential users of these methods. Additionally, an effort is made to obtain the practical limits of the trailing-edge thickness where such problems will appear in the flow solution, and to propose some possible cures for very thin airfoils or those with cusped trailing edges.

  15. Effect of airfoil (trailing-edge) thickness on the numerical solution of panel methods based on the Dirichlet boundary condition

    Science.gov (United States)

    Yon, Steven; Katz, Joseph; Plotkin, Allen

    1992-01-01

    The practical limit of airfoil thickness ratio for which acceptable engineering results are obtainable with the Dirichlet boundary-condition-based numerical methods is investigated. This is done by studying the effect of thickness on the calculated pressure distribution near the trailing edge and by comparing the aerodynamic coefficients with available exact solutions. The first objective of this study, owing to the wide use of such computational methods, is to demonstrate the numerical symptoms that occur when the body or wing thickness approaches zero and to increase the awareness of potential users of these methods. Additionally, an effort is made to obtain the practical limits of the trailing-edge thickness where such problems will appear in the flow solution, and to propose some possible cures for very thin airfoils or those with cusped trailing edges.

  16. Debris thickness and surface topography on Ngozumpa Glacier, Nepal

    Science.gov (United States)

    McCarthy, Michael; Nicholson, Lindsey; Rieg, Lorenzo; Klug, Christoph; Wirbel, Anna; Del Gobbo, Costanza; Pritchard, Hamish; Willis, Ian; Mayer, Christoph

    2017-04-01

    The ablation zones of many Himalayan glaciers are partially to completely covered with a layer of rock debris, the thickness of which is a key control on surface melt rates. Although it is commonly assumed that supraglacial debris is redistributed by gravitational processes due to variable surface topography, the nature of such a relationship has not been fully explored. Here we present locally extensive debris thickness data collected on Ngozumpa Glacier, Nepal, using ground-penetrating radar (GPR), and investigate, by comparison with a high-resolution digital terrain model (DTM), the relationship between debris thickness and surface topography. We compare debris thickness with slope, aspect, and hillslope curvature and look at how debris thickness relates to features of interest on the glacier surface. The existence of a relationship between debris thickness and surface topography has potentially important implications for remote sensing estimates of debris thickness made using thermal band satellite imagery because DTMs are commonly available at relatively high spatial resolution. For this reason, we assess whether or not debris thickness and surface topography covary. Further, due to the typically non-linear relationship between debris thickness and surface temperature, remote sensing estimates of debris thickness are affected by sub-pixel scale debris thickness variability. To see how debris thickness varies at sub-pixel scale, and the extent to which such variability should affect remote sensing-derived debris thickness estimates, we explore the effects of resampling our debris thickness data to the resolution of the thermal bands of ASTER and Landsat satellite images.

  17. Determination of thin film refractive index and thickness by means of film phase thickness

    Science.gov (United States)

    Nenkov, Milen; Pencheva, Tamara

    2008-06-01

    A new approach for determination of refractive index dispersion n(λ) (the real part of the complex refractive index) and thickness d of thin films of negligible absorption and weak dispersion is proposed. The calculation procedure is based on determination of the phase thickness of the film in the spectral region of measured transmittance data. All points of measured spectra are included in the calculations. Barium titanate thin films are investigated in the spectral region 0.38-0.78 μm and their n(λ) and d are calculated. The approach is validated using Swanepoel's method and it is found to be applicable for relatively thin films when measured transmittance spectra have one minimum and one maximum only.

  18. PERIPAPILLARY CHOROIDAL THICKNESS IN CENTRAL SEROUS CHORIORETINOPATHY: Is Choroid Outside the Macula Also Thick?

    Science.gov (United States)

    Yun, Cheolmin; Oh, Jaeryung; Han, Ji Yun; Hwang, Soon-Young; Moon, Sang Woong; Huh, Kuhl

    2015-09-01

    To investigate peripapillary choroidal thickness (CT) outside the macula in central serous chorioretinopathy (CSC). We reviewed the medical records of 34 patients with unilaterally symptomatic idiopathic CSC and 34 age-matched controls. Subfoveal and peripapillary CT were measured from images obtained by spectral domain optical coherence tomography. The nasal peripapillary CT of the choroid outside the macula was determined. The subfoveal CT of CSC (369.74 ± 54.17 μm) and fellow eyes (316.18 ± 54.68 μm) of the patient group were thicker than those of the normal controls (281.90 ± 40.97 μm, all P thick choroids both within and outside the macula, especially when subfoveal CT is increased.

  19. Milky Way's Thick and Thin disk: Is there distinct thick disk?

    CERN Document Server

    Kawata, D

    2016-01-01

    This article is based on our discussion session on Milky Way models at the 592 WE-Heraeus Seminar, Reconstructing the Milky Way's History: Spectroscopic Surveys, Asteroseismology and Chemodynamical models. The discussion focused on the following question: "Are there distinct thick and thin disks?". The answer to this question depends on the definition one adopts for thin and thick disks. The participants of this discussion converged to the idea that there are at least two different types of disks in the Milky Way. However, there are still important open questions on how to best define these two types of disks (chemically, kinematically, geometrically or by age?). The question of what is the origin of the distinct disks remains open. The future Galactic surveys which are highlighted in this conference should help us answering these questions. The almost one-hour debate involving researchers in the field representing different modelling approaches (Galactic models such as TRILEGAL, Besancon and Galaxia, chemica...

  20. Cladding Attachment Over Thick Exterior Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P.; Eng, P.; Lepage, R.

    2014-01-01

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

  1. Cladding Attachment Over Thick Exterior Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

  2. Optically thick outflows in ultraluminous supersoft sources

    CERN Document Server

    Urquhart, Ryan

    2015-01-01

    Ultraluminous supersoft sources (ULSs) are defined by a thermal spectrum with colour temperatures ~0.1 keV, bolometric luminosities ~ a few 10^39 erg/s, and almost no emission above 1 keV. It has never been clear how they fit into the general scheme of accreting compact objects. To address this problem, we studied a sample of seven ULSs with extensive Chandra and XMM-Newton coverage. We find an anticorrelation between fitted temperatures and radii of the thermal emitter, and no correlation between bolometric luminosity and radius or temperature. We compare the physical parameters of ULSs with those of classical supersoft sources, thought to be surface-nuclear-burning white dwarfs, and of ultraluminous X-ray sources (ULXs), thought to be super-Eddington stellar-mass black holes. We argue that ULSs are the sub-class of ULXs seen through the densest wind, perhaps an extension of the soft-ultraluminous regime. We suggest that in ULSs, the massive disk outflow becomes effectively optically thick and forms a large ...

  3. Thickness Effect on Properties of Sprayed In2S3 Films for Photovoltaic Applications

    Science.gov (United States)

    Bouguila, N.; Kraini, M.; Halidou, I.; Lacaze, E.; Bouchriha, H.; Bouzouita, H.

    2016-01-01

    Indium sulfide (In2S3) films have been deposited on soda-lime glass substrates using a spray technique (CSP). Indium chloride and thiourea were used as precursors at a molar ratio of S:In = 2. The substrate temperature was fixed at 340°C. The effect of film thickness on the structural, morphological and optical properties of the as-deposited films has been studied. These films were characterized by x-ray diffraction, scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical absorption spectroscopy. As-prepared samples were polycrystalline with a cubic structure and (400) as preferential orientation. Their grain size increased from 35 nm to 41 nm with increasing thickness whereas the dislocation density and microstrain of the films decreased with the increase of thickness. Both SEM and AFM images showed that the films were homogenous with an increase of the surface roughness with the increase of thickness. The optical transmittance of the films decreased from 80% to 20% in the visible and infrared regions when the thickness was increased from 0.78 μm to 6.09 μm. The optical band gap E g was found to be in the range of 2.75-2.19 eV and showed a decrease with film thickness. Based on the measured optical constants (n and k), a Wemple-Didomenico model was used to determine the values of single oscillator energy ( E 0), dispersion energy ( E d), optical band gap ( E g) and high frequency dielectric constant ( \\varepsilon_{∞} ). In addition, these films exhibited n-type conductivity and were highly resistive. These results confirm that In2S3 thin films are a promising alternative as a buffer-layer material for CuInGa(S,Se)2-based solar cells.

  4. Effect of Thickness of a Water Repellent Soil Layer on Soil Evaporation Rate

    Science.gov (United States)

    Ahn, S.; Im, S.; Doerr, S.

    2012-04-01

    A water repellent soil layer overlying wettable soil is known to affect soil evaporation. This effect can be beneficial for water conservation in areas where water is scarce. Little is known, however, about the effect of the thickness of the water repellent layer. The thickness of this layer can vary widely, and particularly after wildfire, with the soil temperature reached and the duration of the fire. This study was conducted to investigate the effect of thickness of a top layer of water repellent soil on soil evaporation rate. In order to isolate the thickness from other possible factors, fully wettable standard sand (300~600 microns) was used. Extreme water repellency (WDPT > 24 hours) was generated by 'baking' the sand mixed with oven-dried pine needles (fresh needles of Pinus densiflora) at the mass ratio of 1:13 (needle:soil) at 185°C for 18 hours. The thicknesses of water repellent layers were 1, 2, 3 and 7 cm on top of wettable soil. Fully wettable soil columns were prepared as a control. Soil columns (8 cm diameter, 10 cm height) were covered with nylon mesh. Tap water (50 ml, saturating 3 cm of a soil column) was injected with hypoderm syringes from three different directions at the bottom level. The injection holes were sealed with hot-melt adhesive immediately after injection. The rate of soil evaporation through the soil surface was measured by weight change under isothermal condition of 40°C. Five replications were made for each. A trend of negative correlation between the thickness of water repellent top layer and soil evaporation rate is discussed in this contribution.

  5. Smoluchowski coagulation models of sea ice thickness distribution dynamics

    Science.gov (United States)

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

    2011-12-01

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

  6. Foveal thickness after phacoemulsification as measured by optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Gerasimos Th Georgopoulos

    2008-08-01

    Full Text Available Gerasimos Th Georgopoulos, Dimitrios Papaconstantinou, Maria Niskopoulou, Marilita Moschos, Ilias Georgalas, Chrysanthi KoutsandreaGlaucoma Department, Medical School, Athens University, Athens, GreeceBackground: Despite a significant body of research, no consistency on postoperative foveal thickness as measured by optical coherence tomography (OCT, can be recorded. The purpose of our study was to evaluate the effect of uncomplicated cataract surgery in the thickness of the retina in the foveal area during the early postoperative period.Methods: In a prospective study, 79 eyes were assessed by OCT, on day 1, and weeks 2 and 4 after uncomplicated phacoemulsification with intraocular lens implantation in the Athens University Clinic. The outcome measure was the thickness of the retina in the foveal area.Results: The thickness of the retina preoperatively is significantly smaller (150.4 ± 18.8 (p < 0.05 than the thickness of the retina on day 1 (171.8 ± 21 and week 2 (159.7 ± 19 and returned to the initial levels on week 4 (152 ± 17.1. The estimated correlation coefficients between preoperative and postoperative thickness of the retina were significant (p < 0.05. Conversely, no association was found between postoperative visual acuity and thickness of the retina, neither between the phacoemulsification energy and retinal thickness. Operation time, although inversely related with postoperative visual acuity, was not associated with the thickness of the retina.Conclusions: Following phacoemulsification, an increase in the foveal thickness was detected in the early postoperative period, quantified and followed up by OCT. The foveal thickness returned to the preoperative level, 1 month following surgery in our study. No association was shown between intraoperative parameters and increased postoperative retinal thickness.Keywords: optical coherence tomography, phacoemulsification, retinal thickness

  7. Finite element simulation of thick sheet thermoforming

    Science.gov (United States)

    Mercier, Daniel

    This PhD was organized as collaboration between Lehigh University and the Ecole des Mines d'Albi on the subject: "Numerical simulation of thick sheet thermoforming". The research applications cover a wide range of products from thermoforming, e.g., packaging, automobile parts, appliance parts, large-scale panels and covers. Due to the special nature of this PhD, and the requirements of each hosting institutes, the research was split accordingly into two parts: At Lehigh University, under the supervision of Prof. Herman F. Nied, a full three-dimensional finite element program was developed in order to simulate the mechanical deformation during the process of thermoforming. The material behavior is considered hyperelastic with the property of incompressibility. The deformed structure may exhibit symmetries and may use a large choice of boundary conditions. A contact procedure for molds and/or displacements caused by a plug was implemented to complete the similarity with the thermoforming process. The research focused on simulating the observed nonlinear behaviors and their instabilities. The author emphasized the impact of large deformation on the numerical results and demonstrated the need for a remeshing capability. At the Ecole des Mines d'Albi, under the supervision of Prof. Fabrice Schmidt, an equi-biaxial rheometer was developed and built in order to determine the material properties during the process of thermoforming. Thermoplastic materials consist of long macromolecular chains that when stretched, during the process of sheet extrusion, exhibit a transversal isotropic behavior. The rheometer technique is the inflation of a circular membrane made of extruded thermoplastics. The resulting strain is identified by video analysis during the membrane inflation. This dissertation focused on technical issues related to heating with the goal of overcoming the difficulty of producing a homogeneous temperature distribution.

  8. Central Corneal Thickness in Adult Chinese

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The central corneal thickness (CCT) in age 48 years or less of Chinese was characterized and its relationship with gender, age, refraction and intraocular pressure (IOP) was investigated.Right eyes of 1669 participants were included in this study (880 men, 52.7 % and 789 women,47.3 %). Mean age of the samples was 23.8±5.9 years. After the examination of corneal topography and refraction, Goldman applanation tonometry was carried out by one physician. Tonometric values were the mean of three consecutive readings. Subsequently, another physician carried out ultrasonic pachymetry with the DGH 2000 AP ultrasonic pachymeter. Six measuremen ts were made at the center of the cornea of each eye. The mean value was used for analysis. The results showed that mean CCT of male participants was 551.33± 34. 62 μm, 5.79 μm more than that of female participants. Linear regression analyses revealed that CCT was negatively related with age only in female and no association was found between refractive status and CCT. IOP was positively related to CCT, and there was a difference in IOP of 1.5 mmHg (1 mmHg=0. 133 kPa) per 100 μm difference in CCT. Ocular hypertension group was prone to have thicker cornea than average. The results indicated that in adult Chinese CCT tended to decrease with aging in female only. IOP measured by Goldmann tonometry was positively related with CCT so that CCT should be measured along with IOP.

  9. Compton Thick AGN in the COSMOS field

    Science.gov (United States)

    Lanzuisi, Giorgio; Cosmos Collaboration

    2015-09-01

    I will present the results we published in a couple of recent papers (Lanzuisi et al. 2015, A&A 573A 137, Lanzuisi et al. 2015, arXiv 1505.01153) on the properties of X-ray selected Compton Thick (CT, NH>10^24 cm^-2) AGN, in the COSMOS survey. We exploited the rich multi-wavelength dataset available in this field, to show that CT AGN tend to harbor smaller, rapidly growing SMBH with respect to unobscured AGN, and have a higher chance of being hosted by star-forming, merging and post-merger systems.We also demonstrated the detectability of even more heavily obscured AGN (NH>10^25 cm^-2), thanks to a truly multi-wavelength approach in the same field. The extreme source detected in this way shows strong evidences of ongoing powerful AGN feedback, detected as blue-shifted wings of high ionization optical emission lines such as [NeV] and [FeVII], as well as of the [OIII] emission line.The results obtained from these works point toward a scenario in which highly obscured AGN occupy a peculiar place in the galaxy-AGN co-evolution process, in which both the host and the SMBH rapidly evolve toward the local relations.We will also present estimates on the detectability of such extreme sources up to redshift ~6-7 with Athena. Combining the most up to date models for the Luminosity Function of CT AGN at high z, aggressive data analysis techniques on faint sources, and the current Athena survey design, we demonstrate that we will detect, and recognize as such, a small (few to ten) but incredibly valuable sample of CT AGN at such high redshift.

  10. Impact of thickness on microscopic and macroscopic properties of Fe-Te-Se superconductor thin films

    Directory of Open Access Journals (Sweden)

    N. Zhang

    2015-04-01

    Full Text Available A series of iron based Fe-Te-Se superconductor thin films depositing on 0.7wt% Nb-doped SrTiO3 at substrate temperatures in the 250°C -450°C range by pulsed laser ablation of a constituents well defined precursor FeTe0.55Se0.55 target sample. We study the possible growth mechanism and its influence on the superconductor properties. Experimental results indicate the superconductive and non-superconductive properties are modulated only by the thickness of the thin films through the temperature range. The films appear as superconductor whenever the thickness is above a critical value ∼30nm and comes to be non-superconductor below this value. Relative ratios of Fe to (Te+Se in the films retained Fe/(Te+Se1 for non-superconductor no matter what the film growth temperature was. The effect of film growth temperature takes only the role of modulating the ratio of Te/Se and improving crystallinity of the systems. According to the experimental results we propose a sandglass film growth mechanism in which the interfacial effect evokes to form a Fe rich area at the interface and Se or Te starts off a consecutive filling up process of chalcogenide elements defect sides, the process is significant before the film thickness reaches at ∼30nm.

  11. 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.

  12. The damping model for sea waves covered by oil films of a finite thickness

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yanmin; ZHANG Jie; WANG Yunhua; MENG Junmin; ZHANG Xi

    2015-01-01

    In combination with a wave action balance equation, a damping model for sea waves covered by oil films of a finite thickness is proposed. The damping model is not only related to the physical parameters of the oil film, but also related to environment parameters. Meanwhile, the parametric analyses have been also conducted to understand the sensitivity of the damping model to these parameters. And numerical simulations demonstrate that a kinematic viscosity, a surface/interfacial elasticity, a thickness, and a fractional filling factor cause more significant effects on a damping ratio than the other physical parameters of the oil film. From the simulation it is also found that the influences induced by a wind speed and a wind direction are also remarkable. On the other hand, for a thick emulsified oil film, the damping effect on the radar signal induced by the reduction of an effective dielectric constant should also be taken into account. The simulated results are compared with the damping ratio evaluated by the 15 ENVISAT ASAR images acquired during the Gulf of Mexico oil spill accident.

  13. Relationship Between Neck Circumference and Epicardial Fat Thickness in a Healthy Male Population

    Science.gov (United States)

    Küçük, Uğur; Küçük, Hilal Olgun; Cüce, Ferhat; Balta, Sevket

    2016-01-01

    Background: Epicardial fat is an upper body visceral fat depot that may play a significant role in the development of adverse metabolic and cardiovascular risk profiles. There is a significant direct relationship between the amount of epicardial fat and general body adiposity (body mass index, BMI), but data regarding subcutaneous adiposity is limited. Objective: We conducted a study to determine the association between neck circumference and epicardial fat thickness in healthy young male individuals, and assess their individual correlations with general body adiposity and cardiometabolic risk factors. Methods: One hundred consecutive male patients aged 18 years or older with no known major medical conditions were included in the study. All participants underwent detailed physical examination including measurement of blood pressure, weight, height, waist/hip ratio, and neck circumference. Blood was collected to determine fasting glucose and lipid parameters. A standard echocardiographic examination was performed with additional epicardial fat thickness determination. Results: Among 100 study participants, neck circumference correlated significantly with weight, waist circumference, BMI, blood glucose, serum total cholesterol, low-density (LDL)-cholesterol, and triglycerides levels. No significant correlation was found between neck circumference and high-density lipoprotein (HDL)-cholesterol levels. Neck circumference correlated moderately and positively with echocardiographic epicardial fat thickness. Conclusion: Among patients with low cardiometabolic risk, increased neck circumference was associated with increased epicardial fat thickness. PMID:27509093

  14. The structural evolution of galaxies with both thin and thick discs

    Science.gov (United States)

    Aumer, Michael; Binney, James

    2017-09-01

    We perform controlled N-body simulations of disc galaxies growing within live dark matter (DM) haloes to present-day galaxies that contain both thin and thick discs. We consider two types of models: (a) thick-disc initial conditions to which stars on near-circular orbits are continuously added over ∼10 Gyr, and (b) models in which the birth velocity dispersion of stars decreases continuously over the same time-scale. We show that both schemes produce double-exponential vertical profiles similar to that of the Milky Way (MW). We indicate how the spatial age structure of galaxies can be used to discriminate between scenarios. We show that the presence of a thick disc significantly alters and delays bar formation and thus makes possible models with a realistic bar and a high baryon-to-DM mass ratio in the central regions, as required by microlensing constraints. We examine how the radial mass distribution in stars and DM is affected by disc growth and non-axisymmetries. We discuss how bar buckling shapes the vertical age distribution of thin- and thick-disc stars in the bar region. The extent to which the combination of observationally motivated inside-out growth histories and cosmologically motivated dark halo properties leads to the spontaneous formation of non-axisymmetries that steer the models towards present-day MW-like galaxies is noteworthy.

  15. Impact of thickness on the structural properties of high tin content GeSn layers

    Science.gov (United States)

    Aubin, J.; Hartmann, J. M.; Gassenq, A.; Milord, L.; Pauc, N.; Reboud, V.; Calvo, V.

    2017-09-01

    We have grown various thicknesses of GeSn layers in a 200 mm industrial Reduced Pressure - Chemical Vapor Deposition cluster tool using digermane (Ge2H6) and tin tetrachloride (SnCl4). The growth pressure (100 Torr) and the F(Ge2H6)/F(SnCl4) mass-flow ratio were kept constant, and incorporation of tin in the range of 10-15% was achieved with a reduction in temperature: 325 °C for 10% to 301 °C for 15% of Sn. The layers were grown on 2.5 μm thick Ge Strain Relaxed Buffers, themselves on Si(0 0 1) substrates. We used X-ray Diffraction, Atomic Force Microscopy, Raman spectroscopy and Scanning Electron Microscopy to measure the Sn concentration, the strain state, the surface roughness and thickness as a function of growth duration. A dramatic degradation of the film was seen when the Sn concentration and layer thickness were too high resulting in rough/milky surfaces and significant Sn segregation.

  16. Measurements of liquid film thickness, concentration, and temperature of aqueous urea solution by NIR absorption spectroscopy

    Science.gov (United States)

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

    2016-01-01

    A multi-wavelength near-infrared (NIR) diode laser absorption sensor has been developed and demonstrated for real-time monitoring of the thickness, solute concentration, and temperature of thin films of urea-water solutions. The sensor monitors the transmittance of three near-infrared diode lasers through the thin liquid film. Film thickness, urea mass fraction, and liquid temperature were determined from measured transmittance ratios of suitable combinations of lasers. Available laser wavelengths were selected depending on the variation of the NIR absorption spectrum of the solution with temperature and solute concentration. The spectral database was measured by a Fourier transform infrared spectrometer in the range 5500-8000 cm-1 for urea solutions between 5 and 40 wt% and temperatures between 298 and 338 K. A prototype sensor was constructed, and the sensor concept was first validated with measurements using a calibration cell providing liquid layers of variable thickness (200-1500 µm), urea mass fraction (5-40 wt%) and temperature (298-318 K). Temporal variations of film thickness and urea concentration were captured during the constant-temperature evaporation of a liquid film deposited on an optically polished heated quartz flat.

  17. Thickness, permeability and tactile perception of commercial latex examination gloves used in dental practice

    Directory of Open Access Journals (Sweden)

    Shilpa Ashish Warhekar

    2015-01-01

    Full Text Available Introduction: Dentists are at an increased risk of being infected. Some patients may be unaware of their infected status while some patients are unwilling to tell the dentists their disease status. Gloves should be worn in almost all patient procedures. Aim: To assess association between thickness, tactile perception, and permeability of commercial latex examination gloves used in dental practice. Materials and Methods: The experimental study was conducted in Central India. A total of 600 gloves, 120 each from five brands (Kaltex, Nulife, Smartcare, Handshield, Medi-image were used. Thickness was measured using stereomicroscope. Permeability to fluids was evaluated through 0.2% erythrosine dye. Staphylococcus aureus (ATCC-25923 was used to check for microbial permeability. Tactile sensibility was assessed by 2-point discriminator test using 2-point-calipers on 30 volunteers. Chi-square test and Binary logistic regression analysis were used. Results: Mean thickness of gloves was 0.1333 (range: 0.1028-0.1799. Dye and microbial test showed 10.6% and 43.3% permeability of gloves, respectively. No significant difference was observed among brands. Thicker gloves (0.1285-0.1542 yielded lower touch sensibility (odds ratio: 0.783, P < 0.05. Decrease in tactility was recorded in 78.6% of volunteers with gloves compared to no gloves. Conclusion: Considerable microbial permeability suggests commercial examination gloves are unsafe. Balance between thickness, permeability and touch sensation should be established to decrease permeability maintaining same touch sensibility.

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

    Directory of Open Access Journals (Sweden)

    Busi Rambabu

    2014-01-01

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

  19. Transabdominal sonography to measure the total vaginal and mucosal thicknesses.

    Science.gov (United States)

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

    2017-10-01

    Transabdominal and transvaginal sonography are used to measure bladder wall and detrusor thickness. Only transvaginal sonography has been used to measure the vaginal wall thickness. We describe the use of transabdominal sonography to measure the total vaginal wall thickness and total vaginal mucosal thickness at the bladder trigone. The mean bladder wall thickness and SD from published data were within the 95% confidence interval of our data. Total vaginal and mucosal thicknesses are reliable measurements, which require specific evaluation in a postmenopausal population. They could be used to quantify vaginal atrophy and could correlate to symptoms of atrophy and response to treatment. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:461-464, 2017. © 2017 Wiley Periodicals, Inc.

  20. Determination of apparent sampling thickness of sea surface microlayer

    Science.gov (United States)

    Li, Jun; Ding, Hai-Bing; Wu, Zhi-Jian; Zhang, Zheng-Bin; Liu, Lian-Sheng

    1998-06-01

    In situ and laboratory studies of sea—surface microlayer sampling methods using glass plate, rotating drum, screen and funnel samplers were conducted. For glass plate and rotating drum samplers, surface microlayer samples of different thickness were collected by controlling their withdrawal rate and rotating rate. The relationships between pH, surface tension, the concentration of dissolved trace metals Cu and Pb, phosphate, particulate matters and sampling thickness were carefully investigated. It was shown that physicochemical and biological properties change obviously at the sampling thickness of about 50 μm, which is consistent with the mean thickness of the boundary film in the models of gas exchange across the sea surface. It is proposed that the apparent sampling thickness of the surface microlayer should be less than 40 μm. The factors affecting the sampling thickness are discussed, and the feasibility and applicable conditions for different sampling methods are evaluated.

  1. A Librarian's Primer on Financial Ratios.

    Science.gov (United States)

    Kerbel, Sandra Sandor

    1982-01-01

    Explains in simple terms the nature and function of a number of basic types of business and industrial financial ratios. An annotated list of five basic sources for ratios is included and a reference list and bibliography are attached. (JL)

  2. Simultaneous velocity and thickness imaging by ultrasonic scan

    Science.gov (United States)

    Hsu, David K.; Fei, Dong; Shannon, Robert E.; Dayal, Vinay

    2001-04-01

    This paper describes a pulse-echo implementation of the simultaneous velocity and thickness scan technique. The technique was used to measure very small changes in thickness and velocity. Special considerations for achieving accurate and reliable thickness and velocity images are discussed in details. The pulse-echo scan method was also demonstrated for three nondestructive evaluation and material characterization problems: (1) composite laminates containing anomalies, (2) thermal barrier coating materials and (3) creep/rupture tested metal specimens.

  3. Standards for skinfold thickness in British newborn infants.

    Science.gov (United States)

    Oakley, J R; Parsons, R J; Whitelaw, A G

    1977-01-01

    Standards of triceps and subscapular skinfold thicknesses for 1293 Caucasian newborn infants of gestational ages 37-42 weeks, and of 0-25 kg birthweight intervals between 2-25 and 4-5 kg are presented. Female infants had a greater skinfold thickness than males, and the subscapular skinfold was greater than the triceps. The skinfold thickness in both males and females declined after 40 weeks of gestation. PMID:860873

  4. Integrated thick-film nanostructures based on spinel ceramics.

    Science.gov (United States)

    Klym, Halyna; Hadzaman, Ivan; Shpotyuk, Oleh; Brunner, Michael

    2014-03-26

    Integrated temperature-humidity-sensitive thick-film structures based on spinel-type semiconducting ceramics of different chemical compositions and magnesium aluminate ceramics were prepared and studied. It is shown that temperature-sensitive thick-film structures possess good electrophysical characteristics in the region from 298 to 358 K. The change of electrical resistance in integrated thick-film structures is 1 order, but these elements are stable in time and can be successfully used for sensor applications.

  5. Integrated thick-film nanostructures based on spinel ceramics

    OpenAIRE

    Klym, Halyna; Hadzaman, Ivan; Shpotyuk, Oleh; Brunner, Michael

    2014-01-01

    Integrated temperature-humidity-sensitive thick-film structures based on spinel-type semiconducting ceramics of different chemical compositions and magnesium aluminate ceramics were prepared and studied. It is shown that temperature-sensitive thick-film structures possess good electrophysical characteristics in the region from 298 to 358 K. The change of electrical resistance in integrated thick-film structures is 1 order, but these elements are stable in time and can be successfully used for...

  6. An improved method for determining CT image slice thickness.

    Science.gov (United States)

    Schneiders, N J; Bushong, S C

    1981-01-01

    One of the important characteristics of a computed tomography scanner is the image slice thickness. Most phantoms designed to measure this parameter do so with a ramp or tilted wire. Such a phantom must be precisely aligned to avoid possible significant inaccuracy. We present here a procedure for measuring the image slice thickness using a phantom containing two crossed ramps. The procedure produced consistent and accurate measurements of slice thickness without having to carry out a time consuming alignment procedure.

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

    OpenAIRE

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

    2015-01-01

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

  8. Changes in single skinfold thickness in 100 km ultramarathoners.

    Science.gov (United States)

    Knechtle, Beat; Baumgartner, Sabrina; Knechtle, Patrizia; Rüst, Christoph Alexander; Rosemann, Thomas; Bescós, Raúl

    2012-01-01

    Changes in single skinfold thickness and body fat have been investigated in ultraswimmers and ultracyclists, but not in ultrarunners. The present study investigated the changes in single skinfold thickness during a 100 km ultramarathon. Firstly, we investigated associations between prerace preparation and prerace body composition and, secondly, changes in single skinfold thickness during a 100 km ultramarathon in 219 male ultramarathoners. Changes in fat mass and skeletal muscle were estimated using anthropometric methods. Kilometers run weekly prerace and running speed during training were negatively associated with all skinfold thicknesses (P skinfold. During the race, skinfold thickness at the pectoral (-0.1%), suprailiac (-1.8%), and calf (-0.8%) sites decreased (P skinfold thickness were associated with both volume and speed in running training. Secondly, during the ultramarathon, skinfold thickness decreased at the pectoral, suprailiac, and calf sites, but not at the thigh site. Percent decreases in skinfold thickness for ultrarunners was lower than the percent decreases in skinfold thickness reported for ultraswimmers and ultracyclists.

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

    Directory of Open Access Journals (Sweden)

    Kai Yuan

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

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

    Science.gov (United States)

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

    2013-01-01

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

  11. Thickness measurement by using cepstrum ultrasonic signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Chul; Yoon, Chan Hoon; Choi, Heui Joo [Radioactive Waste Disposal Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Jong Sun [Chungnam National University, Daejeon (Korea, Republic of)

    2014-08-15

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

  12. CT artefact reduction by signal to thickness calibration function shaping

    Energy Technology Data Exchange (ETDEWEB)

    Vavrik, Daniel, E-mail: daniel.vavrik@utef.cvut.cz [Institute of Experimental and Applied Physics of the Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences, Prosecka 76, 190 00 Prague 9 (Czech Republic)

    2011-05-15

    It is frequently a task to calibrate the radiogram intensity in reference to the object thickness/density value. This knowledge is important when the radiographic densitometry, thickness measurements or precise computed tomography are required. Often aluminum is used as calibrating material and processed radiogram of the real object is evaluated as aluminum equivalent. This approach is qualitatively convenient for transmission radiograms; however, certain secondary artefacts remain in CT reconstructions. Fortunately the calibration function can be shaped using only one or two known thickness values of the object investigated. The shaped calibration function obtained produces the right signal to thickness relationship and CT quality is improved when it is applied.

  13. Determining Extinction Ratio Of A Laser Diode

    Science.gov (United States)

    Unger, Glenn L.

    1992-01-01

    Improved technique to determine extinction ratio of pulsed laser diode based partly on definition of extinction ratio applicable to nonideal laser pulses. Heretofore, determinations involved assumption of ideal laser pulses, and neglected optical power from background light. Because power fluctuates during real pulse, more realistic to define extinction ratio in terms of energy obtained.

  14. A New Population of Compton-Thick AGN Identified Using the Spectral Curvature Above 10 keV

    CERN Document Server

    Koss, Michael J; Balokovic, M; Stern, D; Gandhi, P; Lamperti, I; Alexander, D M; Ballantyne, D R; Bauer, F E; Berney, S; Brandt, W N; Comastri, A; Gehrels, N; Harrison, F A; Lansbury, G; Markwardt, C; Ricci, C; Rivers, E; Schawinski, K; Treister, E; Urry, C Megan

    2016-01-01

    We present a new metric that uses the spectral curvature (SC) above 10 keV to identify Compton-thick AGN in low-quality Swift BAT X-ray data. Using NuSTAR, we observe nine high SC-selected AGN. We find that high-sensitivity spectra show the majority are Compton-thick (78% or 7/9) and the remaining two are nearly Compton-thick (NH~5-8x10^23 cm^-2). We find the SC_bat and SC_nustar measurements are consistent, suggesting this technique can be applied to future telescopes. We tested the SC method on well-known Compton-thick AGN and find it is much more effective than broad band ratios (e.g. 100% using SC vs. 20% using 8-24/3-8 keV). Our results suggest that using the >10 keV emission may be the only way to identify this population since only two sources show Compton-thick levels of excess in the OIII to X-ray emission ratio (F_OIII/F_2-10 keV>1) and WISE colors do not identify most of them as AGN. Based on this small sample, we find that a higher fraction of these AGN are in the final merger stage than typical B...

  15. Quantitative ultrasound facilitates the exploration of morphological association of the long head biceps tendon with supraspinatus tendon full thickness tear.

    Directory of Open Access Journals (Sweden)

    Ke-Vin Chang

    Full Text Available Pathology of the long head biceps tendon (LHBT is associated with rotator cuff tears but whether the LHBT texture changes following supraspinatus tendon full thickness tear (SSFT can be detected at the extra-articular segment remains unknown. This cross-sectional study aimed to explore the morphological differences of the LHBT in shoulders with and without deficient rotator cuffs by using quantitative ultrasound.We selected 145 cases with SSFT and 145 age-and- gender-matched controls. The width, thickness, flattening ratio, cross-sectional area, and echogenicity ratio of the LHBT were measured and a general linear model was used to clarify the relationship between rotator cuff pathology and LHBT morphology. The receiver operating characteristic curves of each parameter were constructed for SSFT discrimination and the maximal Youden indexes were used to define the best cut-off points.We found increased thickness and cross-sectional area but decreased flattening ratio in shoulders with SSFT, and no between-group differences in the width and echogenicity ratio. The LHBT appearance was modified by biceps peritendinous effusion and medial subluxation, but not by the size of SSFT. The flattening ratio was the best discriminator for SSFT with an area under curve of 0.81 (95% confidence interval, 0.76-0.86. The cut-off values to differentiate between the non-tear and tear groups were 2.00 mm of the thickness, 1.73 of the flattening ratio and 10.53 mm(2 of the cross-sectional area.Quantitative ultrasound facilitated the detection of the LHBT morphological changes following SSFT and demonstrated its potential utility in discriminating rotator cuff deficiency.

  16. A Semi-Analytical Solution for Elastic Analysis of Rotating Thick Cylindrical Shells with Variable Thickness Using Disk Form Multilayers

    Directory of Open Access Journals (Sweden)

    Mohammad Zamani Nejad

    2014-01-01

    Full Text Available Using disk form multilayers, a semi-analytical solution has been derived for determination of displacements and stresses in a rotating cylindrical shell with variable thickness under uniform pressure. The thick cylinder is divided into disk form layers form with their thickness corresponding to the thickness of the cylinder. Due to the existence of shear stress in the thick cylindrical shell with variable thickness, the equations governing disk layers are obtained based on first-order shear deformation theory (FSDT. These equations are in the form of a set of general differential equations. Given that the cylinder is divided into n disks, n sets of differential equations are obtained. The solution of this set of equations, applying the boundary conditions and continuity conditions between the layers, yields displacements and stresses. A numerical solution using finite element method (FEM is also presented and good agreement was found.

  17. 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.

  18. Direct stamping of silver nanoparticles toward residue-free thick electrode

    Science.gov (United States)

    Kim, Jiseok; Wubs, Kevin; Bae, Byeong-Soo; Kim, Woo Soo

    2012-06-01

    Direct stamping of functional materials has been developed for cost-effective and process-effective manufacturing of nano/micro patterns. However, there remain several challenging issues like the perfect removal of the residual layer and realization of high aspect ratio. We have demonstrated facile fabrication of flexible strain sensors that have microscale thick interdigitated capacitors with no residual layer by a simple direct stamping with silver nanoparticles (AgNPs). Polyurethane (PU) prepolymer was utilized as an adhesive layer to transfer AgNPs more efficiently during the separation step of the flexible stamp from directly stamped AgNPs. Scanning electron microscopy images and energy dispersive x-ray spectroscopy analysis revealed residue-free transfer of microscale thick interdigitated electrodes onto two different flexible substrates (elastomeric and brittle) for the application to highly sensitive strain sensors.

  19. Fabrication of sub-12 nm thick silicon nanowires by processing scanning probe lithography masks

    Energy Technology Data Exchange (ETDEWEB)

    Kyoung Ryu, Yu; Garcia, Ricardo, E-mail: r.garcia@csic.es [Instituto de Ciencia de Materiales de Madrid, CSIC, Sor Juana Inés de la Cruz 3, 28049 Madrid (Spain); Aitor Postigo, Pablo; Garcia, Fernando [Instituto de Microelectrónica de Madrid (IMM-CNM-CSIC), 28760 Tres Cantos, Madrid (Spain)

    2014-06-02

    Silicon nanowires are key elements to fabricate very sensitive mechanical and electronic devices. We provide a method to fabricate sub-12 nm silicon nanowires in thickness by combining oxidation scanning probe lithography and anisotropic dry etching. Extremely thin oxide masks (0.3–1.1 nm) are transferred into nanowires of 2–12 nm in thickness. The width ratio between the mask and the silicon nanowire is close to one which implies that the nanowire width is controlled by the feature size of the nanolithography. This method enables the fabrication of very small single silicon nanowires with cross-sections below 100 nm{sup 2}. Those values are the smallest obtained with a top-down lithography method.

  20. A parametric study of a thick, incompressible flow over a curved surface

    Directory of Open Access Journals (Sweden)

    Valeriu DRAGAN

    2011-12-01

    Full Text Available The purpose of this paper is to investigate the lift phenomenon produced by the Coanda effect when a fluid flows over a curved surface. A secondary goal was to quantify and to integrate it on super circulation wing aircraft configurations. Therefore we have conducted a series of CFD studies, varying the fluid velocity and measuring the pressure gradient over the super circulated curved ramp. The results showed that thick jets provide the anticipated lift force which is proportional to the flow velocity. Although in this case the ratio between the Coanda lift and the thrust of the jet itself is less than 10% on average. The immediate interpretation is that, by using thick jets we can increase the lift generated by the SCW aircraft bearing in mind that the main lift is not generated by this effect but rather by diversion of the jet downwards.

  1. Direct stamping of silver nanoparticles toward residue-free thick electrode

    Directory of Open Access Journals (Sweden)

    Jiseok Kim, Kevin Wubs, Byeong-Soo Bae and Woo Soo Kim

    2012-01-01

    Full Text Available Direct stamping of functional materials has been developed for cost-effective and process-effective manufacturing of nano/micro patterns. However, there remain several challenging issues like the perfect removal of the residual layer and realization of high aspect ratio. We have demonstrated facile fabrication of flexible strain sensors that have microscale thick interdigitated capacitors with no residual layer by a simple direct stamping with silver nanoparticles (AgNPs. Polyurethane (PU prepolymer was utilized as an adhesive layer to transfer AgNPs more efficiently during the separation step of the flexible stamp from directly stamped AgNPs. Scanning electron microscopy images and energy dispersive x-ray spectroscopy analysis revealed residue-free transfer of microscale thick interdigitated electrodes onto two different flexible substrates (elastomeric and brittle for the application to highly sensitive strain sensors.

  2. Membrane Thickness Dependence of Nanopore Formation with a Focused Helium Ion Beam

    Directory of Open Access Journals (Sweden)

    Furat Sawafta

    2014-05-01

    Full Text Available Solid-state nanopores are emerging as a valuable tool for the detection and characterization of individual biomolecules. Central to their success is the realization of fabrication strategies that are both rapid and flexible in their ability to achieve diverse device dimensions. In this paper, we demonstrate the membrane thickness dependence of solid-state nanopore formation with a focused helium ion beam. We vary membrane thickness in situ and show that the rate of pore expansion follows a reproducible trend under all investigated membrane conditions. We show that this trend shifts to lower ion dose for thin membranes in a manner that can be described quantitatively, allowing devices of arbitrary dimension to be realized. Finally, we demonstrate that thin, small-diameter nanopores formed with our approach can be utilized for high signal-to-noise ratio resistive pulse sensing of DNA.

  3. Quantitative assessment of macular thickness in normal subjects and patients with diabetic retinopathy by scanning retinal thickness analyser

    Science.gov (United States)

    Oshima, Y.; Emi, K.; Yamanishi, S.; Motokura, M.

    1999-01-01

    AIMS—To evaluate the scanning retinal thickness analyser (RTA), a novel non-invasive imaging instrument, in diagnosing and quantitatively characterising diabetic macular oedema, and to investigate the relation between central macula thickness measured by RTA and other clinical examinations.
METHODS—Central macular thickness was measured using the RTA in 40 normal subjects and 60 patients with diabetic retinopathy. The reproducibility of the retinal thickness measurements was evaluated by calculating the mean of the inter- and intrasession variations. Central macular thickness was correlated with the results of visual acuity measurements, biomicroscopy, and fluorescein angiography.
RESULTS—Intra- and intersession reproducibility of the RTA in normal subjects was plus or minus 5.2% (16 µm) and plus or minus 6.1% (19 µm), respectively. The mean central macular thickness was 182 (SD 16) µm in normal subjects, 283 (116) µm in diabetic eyes without clinically significant macular oedema (CSMO), and 564 (168) µm in diabetic eyes with CSMO. Central macular thickness was significantly greater (p<0.001) in eyes with diabetic retinopathy than in normal subjects, even when macular thickening did not meet the standard for CSMO (p=0.019) measured by biomicroscopy. Although greater fluorescein leakage at the macula results in greater central macular thickness, only eyes with diffuse leakage had statistically significant macular thickening compared with normal subjects (p=0.022). Central macular thickness measured with the RTA was significantly correlated with the logarithmic converted visual acuity (r2= 0.76) in diabetic eyes.
CONCLUSION—Scanning RTA, which has good reproducibility, might be useful to quantitatively detect and monitor macular thickening in diabetic retinopathy. Central macular thickness was highly correlated with logarithmic converted visual acuity in diabetic macular oedema.

 Keywords: scanning retinal thickness analyser; macular

  4. Dynamic changes in optic disc morphology, choroidal thickness, anterior chamber parameters, and intraocular pressure during Valsalva maneuver

    Directory of Open Access Journals (Sweden)

    Alper Mete

    Full Text Available ABSTRACT Purpose: To investigate the effects of the Valsalva maneuver (VM on optic disc morphology, choroidal thickness, and anterior chamber parameters. Methods: This prospective observational study included 60 eyes of 60 healthy subjects. The anterior chamber parameters, including central corneal thickness (CCT, anterior chamber depth (ACD, anterior chamber angle (ACA, anterior chamber volume (ACV, pupil diameter (PD, axial length (AL, subfoveal and peripapillary choroidal thickness, optic disc parameters, and intraocular pressure (IOP, were measured at rest and during VM. Results: VM did not have any significant influence on AL, subfoveal and peripapillary choroidal thickness, optic disc area, rim area, cup area, cup-to-disc area ratio, vertical cup-to-disc ratio, rim volume, cup volume, and nerve head volume measurements (for all; p >0.05. IOP and PD significantly increased during VM (for both; p <0.001. VM significantly decreased CCT, ACD, ACA, and ACV values (for all; p <0.001. Moreover, the optic nerve cup volume decreased and the horizontal cup-to-disc ratio significantly increased during VM (for both; p <0.05. Conclusions: VM may cause transient changes in IOP, optic disc morphology, and anterior chamber parameters.

  5. Poisson's ratio and Young's modulus of lipid bilayers in different phases

    Directory of Open Access Journals (Sweden)

    Tayebeh eJadidi

    2014-04-01

    Full Text Available A general computational method is introduced to estimate the Poisson's ratio for membranes with small thickness.In this method, the Poisson's ratio is calculated by utilizing a rescaling of inter-particle distancesin one lateral direction under periodic boundary conditions. As an example for the coarse grained lipid model introduced by Lenz and Schmid, we calculate the Poisson's ratio in the gel, fluid, and interdigitated phases. Having the Poisson's ratio, enable us to obtain the Young's modulus for the membranes in different phases. The approach may be applied to other membranes such as graphene and tethered membranes in orderto predict the temperature dependence of its Poisson's ratio and Young's modulus.

  6. Estimating the aggregate/intraaggregate mass ratio of a shrinking soil

    CERN Document Server

    Chertkov, V Y

    2014-01-01

    A recently introduced parameter, the ratio of an aggregate solid mass to a solid mass of an intraaggregate matrix (K ratio) is connected with the mean thickness of a deformable, but non-shrinking surface layer of aggregates and is a fundamental property of aggregated soils that essentially influences their shrinkage. The objective of this work is to suggest and validate an approach to estimating the K ratio at any soil clay content through characteristics of soil texture and structure. We derive an equation that reflects the interrelation between the K ratio and soil texture and structure. The K ratio can be estimated as the solution of the equation and is determined by the mean size of soil solids and the maximum size of soil aggregates in the oven-dried state, independently of a measured shrinkage curve. To validate the approach we use available data for eight soils.

  7. Elasto-Plasticity Critical Corrosive Ratio Model for RC Structure Corrosive Expanding Crack

    Institute of Scientific and Technical Information of China (English)

    CHEN Yueshun; LU Yiyan; LIU Li

    2007-01-01

    The parameter of filling expanding ratio n, plasticity factor k1 and deformation parameter k2 is raised, and then the elasto-plasticity critical corrosive ratio model for RC structure corrosive expanding crack based on elasto-plasticity theory is constructed in this paper. The influences of parameters such as filling expansion ratio n, plasticity factor k1, deformation parameter k2, Poisson ratio of concrete v, diameter of reinforced bar d and protective layer thickness c on the critical corrosive ratio are researched by theory analysis and experiments. The experimental results validate the accuracy of the model. According to the experimental study, the least squares solution is calculated as n=1.8,k1 =0.61,k2 =0.5.

  8. Choroidal Thickness in Children with Beta Thalassemia Major.

    Science.gov (United States)

    Simsek, Ali; Tekin, Mehmet; Bilak, Semsettin; Karadag, Ayse Sevgi; Konca, Capan; Almis, Habip

    2016-06-01

    The purpose of this study was to determine whether there are differences in choroidal thickness in children with beta thalassemia major (β-TM). Thirty-five patients with β-TM and 38 healthy children aged between 3 and 16 years participated in the study. After complete eye examinations were conducted on the participants, choroidal thickness measurements were performed using optical coherence tomography. Correlations between choroidal thickness and laboratory and clinical parameters, such as age, sex, hemoglobin and ferritin levels, duration of disease, type and duration of chelating therapy, visual acuity, intraocular pressure, central corneal thickness, and axial length were also evaluated. The mean ages for the study group and for the control group were 8.2 ± 2.7 and 7.9 ± 2.4 years, respectively. There were no statistical differences between groups in terms of visual acuity, intraocular pressure, central corneal thickness, or axial length (p > 0.05). Choroidal thicknesses at the foveal center were 286 ± 33 μm in β-TM patients and 335 ± 423 μm in the healthy control children. Choroidal thicknesses at each point within the horizontal nasal and temporal quadrants were thinner in the β-TM group. There was a positive correlation between choroidal thickness and hemoglobin levels and a negative correlation between choroidal thickness and ferritin levels (r = 0.924, p choroidal thickness. Choroidal thickness was significantly thinner in all quadrants in children with β-TM. This thinning of the choroid may be the reason for the development of eye disorders in older patients with β-TM.

  9. Formation of hybrid arc andesites beneath thick continental crust

    Science.gov (United States)

    Straub, Susanne M.; Gomez-Tuena, Arturo; Stuart, Finlay M.; Zellmer, Georg F.; Espinasa-Perena, Ramon; Cai, Yue; Iizuka, Yoshiyuki

    2011-03-01

    Andesite magmatism at convergent margins is essential for the differentiation of silicate Earth, but no consensus exists as to andesite petrogenesis. Models proposing origin of primary andesite melts from mantle and/or slab materials remain in deadlock with the seemingly irrefutable petrographic and chemical evidence for andesite formation through mixing of basaltic mantle melts with silicic components from the overlying crust. Here we use 3He/4He ratios of high-Ni olivines to demonstrate the mantle origin of basaltic to andesitic arc magmas in the central Mexican Volcanic Belt (MVB) that is constructed on ~ 50 km thick continental crust. We propose that the central MVB arc magmas are hybrids of high-Mg# > 70 basaltic and dacitic initial mantle melts which were produced by melting of a peridotite subarc mantle interspersed with silica-deficient and silica-excess pyroxenite veins. These veins formed by infiltration of reactive silicic components from the subducting slab. Partial melts from pyroxenites, and minor component melts from peridotite, mix in variable proportions to produce high-Mg# basaltic, andesitic and dacitic magmas. Moderate fractional crystallization and recharge melt mixing in the overlying crust produces then the lower-Mg# magmas erupted. Our model accounts for the contrast between the arc-typical SiO2 variability at a given Mg# and the strong correlation between major element oxides SiO2, MgO and FeO which is not reproduced by mantle-crust mixing models. Our data further indicate that viscous high-silica mantle magmas may preferentially be emplaced as intrusive silicic plutonic rocks in the crust rather than erupt. Ultimately, our results imply a stronger turnover of slab and mantle materials in subduction zones with a negligible, or lesser dilution, by materials from the overlying crust.

  10. Application of Performance Ratios in Portfolio Optimization

    Directory of Open Access Journals (Sweden)

    Aleš Kresta

    2015-01-01

    Full Text Available The cornerstone of modern portfolio theory was established by pioneer work of Harry Markowitz. Based on his mean-variance framework, Sharpe formulated his well-known Sharpe ratio aiming to measure the performance of mutual funds. The contemporary development in computer’s computational power allowed to apply more complex performance ratios, which take into account also higher moments of return probability distribution. Although these ratios were proposed to help the investors to improve the results of portfolio optimization, we empirically demonstrated in our paper that this may not necessarily be true. On the historical dataset of DJIA components we empirically showed that both Sharpe ratio and MAD ratio outperformed Rachev ratio. However, for Rachev ratio we assumed only one level of parameters value. Different set-ups of parameters may provide different results and thus further analysis is certainly required.

  11. Spectral ratio method for measuring emissivity

    Science.gov (United States)

    Watson, K.

    1992-01-01

    The spectral ratio method is based on the concept that although the spectral radiances are very sensitive to small changes in temperature the ratios are not. Only an approximate estimate of temperature is required thus, for example, we can determine the emissivity ratio to an accuracy of 1% with a temperature estimate that is only accurate to 12.5 K. Selecting the maximum value of the channel brightness temperatures is an unbiased estimate. Laboratory and field spectral data are easily converted into spectral ratio plots. The ratio method is limited by system signal:noise and spectral band-width. The images can appear quite noisy because ratios enhance high frequencies and may require spatial filtering. Atmospheric effects tend to rescale the ratios and require using an atmospheric model or a calibration site. ?? 1992.

  12. Exposure to Violence and Carotid Artery Intima-Media Thickness in Mexican Women.

    Science.gov (United States)

    Flores-Torres, Mario H; Lynch, Rebekka; Lopez-Ridaura, Ruy; Yunes, Elsa; Monge, Adriana; Ortiz-Panozo, Eduardo; Cantu-Brito, Carlos; Hauksdóttir, Arna; Valdimarsdóttir, Unnur; Lajous, Martín

    2017-08-17

    Violence against women has become a global public health threat. Data on the potential impact of exposure to violence on cardiovascular disease are scarce. We evaluated the association between exposure to violence and subclinical cardiovascular disease in 634 disease-free women from the Mexican Teachers' Cohort who responded to violence-related items from the Life Stressor Checklist and underwent measures of carotid artery intima-media thickness in 2012 and 2013. We defined exposure to violence as having ever been exposed to physical and/or sexual violence. Intima-media thickness was log-transformed, and subclinical carotid atherosclerosis was defined as intima-media thickness ≥0.8 mm or plaque. We used multivariable linear and logistic regression models adjusted for several potential confounders. Mean age was 48.9±4.3 years. Close to 40% of women reported past exposure to violence. The lifetime prevalence of sexual violence was 7.1%, and prevalence of physical violence was 23.5% (7.7% reported both sexual and physical violence). Relative to women with no history of violence, exposure to violence was associated with higher intima-media thickness (adjusted mean percentage difference=2.4%; 95% confidence interval 0.5, 4.3) and subclinical atherosclerosis (adjusted odds ratio=1.60; 95% confidence interval 1.10, 2.32). The association was stronger for exposure to physical violence, especially by mugging or physical assault by a stranger (adjusted mean % difference=4.6%; 95% confidence interval 1.8, 7.5, and odds ratio of subclinical carotid atherosclerosis=2.06; 95% confidence interval 1.22, 3.49). Exposure to violence, and in particular assault by a stranger, was strongly associated with subclinical cardiovascular disease in Mexican middle-aged women. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  13. [Cut-off point of epicardial adipose tissue thickness for predicting metabolic syndrome in Venezuelan population].

    Science.gov (United States)

    Lima-Martínez, Marcos M; Paoli, Mariela; Donis, José H; Odreman, Rodolfo; Torres, Christopher; Iacobellis, Gianluca

    2013-12-01

    To define an echocardiographically-assessed cut-off point for epicardial adipose tissue (EAT) thickness associated to metabolic syndrome (MS) components in Venezuelan subjects. Fifty-two subjects aged 20-65 years diagnosed with MS according to International Diabetes Federation criteria and 45 sex- and age-matched controls were selected. Blood glucose and plasma lipids were tested; EAT thickness and left ventricular mass were measured by echocardiography. No significant age and sex differences were found between the two groups. Body weight, body mass index, waist circumference, and systolic and diastolic blood pressure were significantly higher (P=.0001) in the MS group. This group showed significantly higher levels of fasting blood glucose (P=.0001), total cholesterol (P=.002), LDL-C (P=.007), non-HDL-C (P=.0001), triglycerides (P=.0001), Tg-HDL-C ratio (P=.0001), and lower HDL-C levels (P=.0001) as compared to the control group. EAT thickness (P=.0001) and left ventricular mass (P=.017) were significantly higher in the MS group. The ROC curve showed an AUC of 0.852 (P=.0001) with a power of the test of 0.99. A 5-mm EAT thickness showed a sensitivity of 84.62% (95%CI: 71.9-93.1) and a specificity of 71.11% (95%CI: 55.7-83.6) for predicting MS. The odds ratio of this population for experiencing MS due to an EAT ≥ 5 mm was 8.25 (95%CI: 3.15-21.56; P=.0001). An EAT value ≥ 5 mm has good sensitivity and specificity for predicting MS in the Venezuelan population. Copyright © 2012 SEEN. Published by Elsevier Espana. All rights reserved.

  14. Relationship between leukoaraiosis, carotid intima-media thickness and intima-media thickness variability: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Lucatelli, Pierleone [University of Rome la Sapienza, Department of Radiology, Rome (Italy); Raz, Eytan [New York University Langone Medical Center, Department of Radiology, New York, NY (United States); Saba, Luca [Azienda Ospedaliero Universitaria, Department of Radiology, di Cagliari - Polo di Monserrato, Cagliari (Italy); Argiolas, Giovanni Maria; Siotto, Paolo [Azienda Ospedaliera Brotzu, Department of Radiology, Cagliari (Italy); Montisci, Roberto [Azienda Ospedaliero Universitaria, Department of Vascular Surgery, di Cagliari - Polo di Monserrato, Cagliari (Italy); Wintermark, Max [University of Virginia, Department of Radiology, Neuroradiology Division, 1215 Lee Street-New Hospital, PO Box 800170, Charlottesville, VA (United States); King, Kevin S. [University of Texas Southwestern Medical Center, Department of Radiology, Dallas, TX (United States); Molinari, Filippo [Politecnico di Torino, Biolab, Department of Electronics, Torino (Italy); Ikeda, Nobutaka [Toho University Ohashi Medical Center, Division of Cardiovascular Medicine, Tokyo (Japan); Suri, Jasjit S. [AtheroPoint trademark LLC, Diagnostic and Monitoring Division, Roseville, CA (United States); University of Idaho, Department of Electrical Engineering, Pocatello, ID (United States)

    2016-12-15

    To assess the relationship between the degree of leukoaraiosis (LA), carotid intima-media thickness (IMT) and intima-media thickness variability (IMTV). Sixty-one consecutive patients, who underwent a brain MRI examination and a carotid artery ultrasound, were included in this retrospective study, which conformed with the Declaration of Helsinki. Written informed consent was waived. In each patient, right/left carotid arteries and brain hemispheres were assessed using automated software for IMT, IMTV and LA volume. The mean hemispheric LA volume was 2,224 mm{sup 3} (SD 2,702 mm{sup 3}) and there was no statistically significant difference in LA volume between the right and left hemispheres (p value = 0.628). The mean IMT and IMTV values were 0.866 mm (SD 0.170) and 0.143 mm (SD 0.100), respectively, without significant differences between the right and left sides (p values 0.733 and 0.098, respectively). The correlation coefficient between IMTV and LA volume was 0.41 (p value = 0.0001), and 0.246 (p value = 0.074) between IMT and LA volume. IMTV significantly correlates with LA volume. Further studies are warranted to verify whether this parameter can be used clinically as a marker of cerebrovascular risk. (orig.)

  15. Milky Way's thick and thin disk: Is there a distinct thick disk?

    Science.gov (United States)

    Kawata, D.; Chiappini, C.

    2016-09-01

    This article is based on our discussion session on Milky Way models at the 592 WE-Heraeus Seminar, Reconstructing the Milky Way's History: Spectroscopic Surveys, Asteroseismology and Chemodynamical Models. The discussion focused on the following question: "Are there distinct thick and thin disks?". The answer to this question depends on the definition one adopts for thin and thick disks. The participants of this discussion converged to the idea that there are at least two different types of disks in the Milky Way. However, there are still important open questions on how to best define these two types of disks (chemically, kinematically, geometrically or by age?). The question of what is the origin of the distinct disks remains open. The future Galactic surveys which are highlighted in this conference should help us answering these questions. The almost one-hour debate involving researchers in the field representing different modelling approaches (Galactic models such as TRILEGAL, Besançon and Galaxia, chemical evolution models, extended distribution functions method, chemodynamics in the cosmological context, and self-consistent cosmological simulations) illustrated how important is to have all these parallel approaches. All approaches have their advantages and shortcomings (also discussed), and different approaches are useful to address specific points that might help us answering the more general question above.

  16. Micro-structural evaluation of Ti/Al/Ni/Au ohmic contacts with different Ti/Al thicknesses in AlGaN/GaN HEMTs

    Energy Technology Data Exchange (ETDEWEB)

    Mahajan, Somna S., E-mail: somnamahajan@gmail.com; Dhaul, Anuradha; Laishram, Robert; Kapoor, Sonalee; Vinayak, Seema; Sehgal, B.K.

    2014-04-01

    Highlights: • Ohmic contacts with four different Ti/Al metal thickness ratios were fabricated on undoped Al{sub .28}Ga{sub .72}N/GaN HEMT under various annealing cycles using Rapid thermal processor. • Ohmic contact with Ti/Al metal thickness ratio, 1/5 showed superior quality in terms of R{sub c} and surface morphology. • Ni–Al alloy segregation on the surface as analyzed by EDAX seems to be related to bumpy surface morphology. • Ohmic contact with Ti/Al metal ratio 1/5 showed the presence of TiN by X-ray diffraction analysis. This was further confirmed by SIMS analysis. • The lower level of elemental Ti and Al at the surface of the contact with Ti/Al metal thickness ratio 1/5 compared to the other contacts indicated lower oxidation possibility and therefore superior quality ohmic contacts with the metal ratio 1/5. - Abstract: In this work, ohmic contacts were formed by varying the Ti/Al thickness ratio in the metal stack of Ti/Al/Ni/Au on Al{sub .28}Ga{sub .72}N/GaN HEMT epistructure followed by annealing in the temperature range 740–860 °C by rapid thermal processor (RTP). The contacts were electrically characterized for contact resistance (R{sub c}) and the sheet resistance (R{sub s}) of AlGaN/GaN epistructure. The ohmic contacts formed by Ti/Al metal thickness ratio of 1/5 exhibited lowest R{sub c} values and better surface morphology compared to the contacts formed by other Ti/Al metal thickness ratios. The difference observed in the electrical characterization of these contacts was correlated with their X-ray diffraction (XRD) and secondary ion mass spectroscopy (SIMS) analyses. The surface morphology of the ohmic metal post annealing showed two distinct regions in scanning electron microscope (SEM) images. The energy dispersive X-ray analysis (EDAX) identified these regions as Ni–Al and Au–Al rich. Ni–Al rich region is believed to be responsible for rough morphology. Further, the contact formed with Ti/Al metal thickness ratio 1

  17. Venusian highlands - Geoid to topography ratios and their implications

    Science.gov (United States)

    Smrekar, Suzanne E.; Phillips, Roger J.

    1991-01-01

    Geoid-to-topography ratios (GTRs) are estimated for 12 Venusian highland features to allow comparison with convection calculations and with terrestrial data of oceanic hot spots, swells, and plateaus. The geoid is estimated in the wavenumber domain from the isostatic formula, using the topography and the apparent depths isostatic compensation (ADC) for each region. In the space domain, the GTR is equal to the least squares slope of the linear fit of the geoid to the topograpy. The resulting GTR range is 7-31 m/km, which is much higher than terrestrial oceanic values (-1 to 5 m/km). The features fall into two distinct groups, one with a GTR range of 7-13 m/km, and one with a range of 19-25 m/km. A model for thermal thinning of a 100-km-thick lithosphere fits all values in the lower GTR group to within one standard deviation.

  18. Fires and Thick Smoke Across Southeast Asia

    Science.gov (United States)

    2007-01-01

    Vehicles and power plants are not the only sources of air pollution and greenhouses gases: fires contribute, too. In the Northern Hemisphere spring, which is the end of dry season across much of Southeast Asia, thousands of fires burn each year as people clear cropland and pasture in anticipation of the upcoming wet (growing) season. Intentional fires also escape people's control and burn into adjacent forest. The smoke from these fires crosses the Pacific Ocean, affecting climate far away. This dramatic photo-like image of fires and smoke in Southeast Asia was captured on April 2, 2007, by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite. MODIS detected hundreds, possibly thousands of fires (marked in red), burning in Thailand, Laos, Vietnam, and China. Thick smoke hides nearly all of Laos, where the highest concentration of fires is located. In southern China and northern Vietnam, the smoke has sunk into the valleys that crisscross the mountainous terrain; only the highest ridgelines, which appear dark green, emerge from the blanket of smoke. The smoke sails above a bank of clouds at upper right as a dingy, yellowish haze. Fires have been burning in the region for more than month, as shown by the high carbon monoxide levels observed by NASA's MOPITT sensor during March 2007. In addition to carbon dioxide and other greenhouse gases, fires produce tiny particles of incompletely burned, or charred, carbon. According to research published in mid-March 2007 in the Journal of Geophysical Research, significant amounts of this black carbon travel across the Pacific Ocean to North America at altitudes above 2 kilometers. In spring 2004, between 25-35 gigatons (roughly 55 to 77 million pounds) of black carbon crossed the Pacific and entered skies over western North America between March 26 and April 25; nearly 75 percent of it came from Asia. (Smoke and other pollution have no respect for borders; for example, scientists have also

  19. O and Fe abundance correlations and distributions inferred for the thick and thin disk

    Directory of Open Access Journals (Sweden)

    Caimmi R.

    2015-01-01

    Full Text Available A linear [Fe/H]-[O/H] relation is found for different stellar populations in the Galaxy (halo, thick disk, thin disk from a data sample obtained in a recent investigation (Ramґırez et al. 2013. These correlations support previous results inferred from poorer samples: stars display a “main sequence” expressed as [Fe/H] = a[O/H] + b -+ Δb where the unit slope, a = 1, implies a constant [O/Fe] abundance ratio. Oxygen and iron empirical abundance distributions are then determined for different subsamples, which are well explained by the theoretical predictions of multistage closed-(box+reservoir (MCBR chemical evolution models taking into account the found correlations. The interpretation of these distributions in the framework of MCBR models gives us clues about inflow/outflow rates in these different Galactic regions and their corresponding evolution. Outflow rates for the thick and the thin disks are lower than the halo outflow rate. Besides that, the iron-to-oxygen yield ratio and the primary to not primary contribution ratio for the iron production are obtained from the data, resulting consistent with the SNII progenitor nucleosynthesis and with the iron production from SNIa supernova events.

  20. 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.

  1. Influence of La-Mn-Al Co-Doping on Dielectric Properties and Structure of BST Thick Film

    Institute of Scientific and Technical Information of China (English)

    Mao-Yan Fan; Sheng-Lin Jiang

    2009-01-01

    A new sol-gel process is applied to fabricate the BST (BaxSr1(xTiO3) sol and nano-powder of La-Mn-Al co-doping with Ba/Sr ratio 65/35, and the BST thick film is prepared in the Pt/Ti/SiO2/Si substrate. The powder and thick film are characterized by X-ray diffraction and transmission electron microscope. The influence of La-Mn-Al co-doping on the dielectric properties and micro-structure of BST thick film is analyzed. The results show that the La, Mn, and Al ions can take an obvious restraint on the growth of BaSrTiO3 grains. The polycrystalline particles come into being during the crystallization of thick film, which may improve the uniformity and compactness of thick film. The influence of unequal-valence and doping amount on the leakage current, dielectric loss, and dielectric property are mainly discussed. The dielectric constant and dielectric loss of thick film are 1200 and 0.03, respectively, in the case of 1mol% La doping, 2mol% Mn doping, and 1mol% Al doping.

  2. The effect of grain size and film thickness on the thermal expansion coefficient of copper thin films.

    Science.gov (United States)

    Hwang, Seulgi; Kim, Youngman

    2011-02-01

    Cu thin films underwent thermal cycling to determine their coefficient of thermal expansion (CTE). The thermal stress of the Cu thin films with various microstructures (different grain size and film thickness) was measured using a curvature measurement system. The thermal expansion coefficients of the films were obtained from the slope of the stress-temperature curve with the knowledge of the Young's modulus and Poisson's ratio. The change in thermal stress with temperature of the Cu thin films tended to decrease with increasing grain size, resulting in an increase in the CTE. The thickness of Cu thin film had little effect on the thermal stress or the CTE.

  3. Thickness and dielectric constant determination of thin dielectric layers

    NARCIS (Netherlands)

    Bruijn, de Helene E.; Minor, Marcel; Kooyman, Rob P.H.; Greve, Jan

    1993-01-01

    We derive a method for the determination of the dielectric constant and thickness of a thin dielectric layer, deposited on top of a thick dielectric layer which is in turn present on a metal film. Reflection of p- and s-polarized light from the metal layer yields minima for certain angles of inciden

  4. Thickness mapping of high-κ dielectrics at the nanoscale

    OpenAIRE

    Trapnauskas, Justinas; ROMMEL, M.; Bauer, A.J.; Frey, L

    2014-01-01

    Contact potential difference measurements by Kelvin probe force microscopy (KPFM) together with corona charging was applied for contactless equivalent oxide thickness (EOT) mapping with nanometer range lateral resolution. Characterization was performed under ambient conditions and compared to a conventional macroscale method based on Kelvin probe measurements. The presented method is directly applicable for dielectrics with homogeneous thicknesses. For other dielectric layers, the implemented...

  5. Estimate of shock thickness based on entropy production

    Science.gov (United States)

    Thompson, P. A.; Strock, T. W.; Lim, D. S.

    1983-01-01

    The shock thickness is estimated for a stationary shock in an ideal gas by equating the internal entropy production to the entropy increase found from the Rankine-Hugoniot equation. For elementary assumed profiles, the thickness is expressed by a simple formula. For realistic dependence of viscosity on temperature, results are in qualitative agreement with experiment.

  6. Simulations of minor mergers. I. General properties of thick disks

    NARCIS (Netherlands)

    Villalobos, Álvaro; Helmi, Amina

    2008-01-01

    We present simulations of the formation of thick disks via the accretion of twocomponent satellites onto a pre-existing thin disk. Our goal is to establish the detailed characteristics of the thick disks obtained in this way, as well as their dependence on the initial orbital and internal properties

  7. Longitudinal changes in choroidal thickness and eye growth in childhood.

    Science.gov (United States)

    Read, Scott A; Alonso-Caneiro, David; Vincent, Stephen J; Collins, Michael J

    2015-05-01

    To examine longitudinal changes in choroidal thickness and axial length in a population of children with a range of refractive errors. One hundred and one children (41 myopes and 60 nonmyopes) aged 10 to 15 years participated in this prospective, observational longitudinal study. For each child, 6-month measures of choroidal thickness (using enhanced depth imaging optical coherence tomography) and axial ocular biometry were collected four times over an 18-month period. Linear mixed-models were used to examine the longitudinal changes in choroidal thickness and the relationship between changes in choroidal thickness and axial eye growth over the study period. A significant group mean increase in subfoveal choroidal thickness was observed over 18 months (mean increase 13 ± 22 μm, P choroids compared with nonmyopic children (P choroidal thickness over time in myopes and nonmyopes. However, a significant association between the change in choroidal thickness and the change in axial length over time was found (P choroidal thickening over time compared with children showing slower axial eye growth. A significant increase in choroidal thickness occurs over an 18-month period in normal 10- to 15-year-old children. Children undergoing faster axial eye growth exhibited less thickening and, in some cases, a thinning of the choroid. These findings support a potential role for the choroid in the mechanisms regulating eye growth in childhood.

  8. Film thickness in grease lubricated slow rotating rolling bearings

    NARCIS (Netherlands)

    Morales-Espejel, G.E.; Lugt, Pieter Martin; Pasaribu, H.R.; Cen, H.

    2014-01-01

    Film thickness measurements in grease lubricated contacts are presented for different greases. The conditions used in the experiments are similar to the ones expected in fully-flooded slow rotating bearings. The results show that at very low speeds grease produces film thicknesses substantially thic

  9. Pelvic floor muscle thickness measured by perineal ultrasonography

    DEFF Research Database (Denmark)

    Bernstein, Inge Thomsen; Juul, N; Grønvall, S

    1991-01-01

    Pelvic floor muscle thickness was assessed in nine healthy female physiotherapists by perineal sonography. All measurements were performed as triple-measurements. The aims were to assess the reliability of the measurements and to establish a reference material. The muscle thickness at rest...

  10. Sputtering of Thick Deuterium Films by KeV Electrons

    DEFF Research Database (Denmark)

    Thestrup Nielsen, Birgitte; Svendsen, Winnie Edith; Schou, Jørgen;

    1994-01-01

    Sputtering of thick films of solid deuterium up to several μm by keV electrons is reported for the first time. The sputtering yield increases within a narrow range of thicknesses around 1.6 μm by about 2 orders of magnitude for 1.5 keV electrons. A similar behavior has not been observed for ion...

  11. Determination of thin layer thickness from alpha particle energy spectra

    Energy Technology Data Exchange (ETDEWEB)

    Hnatowicz, V.; Kvitek, J. (Ceskoslovenska Akademie Ved, Prague. Ustav pro Elektrotechniku); Rybka, V.; Krejci, P. (Tesla, Prague (Czechoslovakia). Vyzkumny Ustav pro Sdelovaci Techniku); Pelikan, L. (Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Fakulta Elektrotechnicka); Mikusik, P. (Ceskoslovenska Akademie Ved, Prague. Ustav Fyzikalni Chemie a Elektrochemie J. Heyrovskeho)

    1982-10-01

    A method which uses alpha particles from the /sup 10/B(n,alpha)/sup 7/Li nuclear reaction for the determination of surface layer thicknesses is described and experimentally checked. The thickness measurements can be performed on samples implanted with boron.

  12. 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....

  13. Simulations of minor mergers. I. General properties of thick disks

    NARCIS (Netherlands)

    Villalobos, Álvaro; Helmi, Amina

    2008-01-01

    We present simulations of the formation of thick disks via the accretion of twocomponent satellites onto a pre-existing thin disk. Our goal is to establish the detailed characteristics of the thick disks obtained in this way, as well as their dependence on the initial orbital and internal properties

  14. Thickness dependence of vortex critical velocity in wide Nb films

    Energy Technology Data Exchange (ETDEWEB)

    Grimaldi, Gaia [CNR-INFM Regional Laboratory SuperMat, Via S. Allende, Baronissi, SA, I-84081 (Italy)], E-mail: grimaldi@sa.infn.it; Leo, Antonio; Nigro, Angela; Pace, Sandro; Cirillo, Carla; Attanasio, Carmine [CNR-INFM Regional Laboratory SuperMat, Via S. Allende, Baronissi, SA, I-84081 (Italy); Dipartimento di Fisica ' E.R. Caianiello' , Universita di Salerno, Via S. Allende, Baronissi, SA, I-84081 (Italy)

    2008-04-01

    Pulsed I-V measurements performed on wide Nb films of different thickness show the electronic instability, at high driving currents, predicted by Larkin and Ovchinnikov (LO). We find that the associated vortex critical velocity v* decreases with the film thickness, and its temperature and magnetic field dependences exhibit some discrepancies with respect to the LO theoretical results.

  15. Freshwater ice thickness observations using passive microwave sensors

    Science.gov (United States)

    Hall, D. K.; Foster, J. L.; Chang, A. T. C.; Rango, A.

    1981-01-01

    Walden Reservoir, a freshwater lake in north-central Colorado, was overflown six times by a NASA C-130 aircraft between January 1977 and April 1980. The aircraft was equipped with four microwave radiometers operating between 0.81 and 6.0 cm in wavelength (37.0 to 5.0 GHz). The 6.0-cm radiometer data showed a good relationship with ice thickness based on a sample of four ice thickness values. The 1.67- and 1.35-cm radiometer data showed weaker relationships with ice thickness. The 0.81-cm sensor data showed no positive relationship with ice thickness. None of the relationships was statistically significant because of the small sample size. The 6.0-cm sensor data in the nadir-viewing mode was found to have the most potential of all the wavelengths studied, for use in remotely determining ice thickness. The 6.0-cm radiometer probably sensed the entire thickness of the ice on the reservoir (ranging from 25.4 to 67.3 cm in thickness) and was apparently not significantly affected by the snow overlying the ice. The shorter wavelengths are scattered by the snow overlying the ice and are more suitable for snow studies than for ice thickness studies.

  16. Measuring the Thickness of a Transparent Ring with a Laser

    Science.gov (United States)

    Leung, Alfred F.

    2007-01-01

    There seems to be no reasonable way to measure the thickness of a narrow-mouth glass bottle. One can measure the outer and inner diameters of the mouth with a ruler or a pair of calipers and then calculate the thickness. However, this measurement might be interfered with by the threads at the mouth. Furthermore, it is uncertain whether the…

  17. Health Monitoring of Thick Materials Using Piezoceramic Patches, Time Signals, and Wavelet Transmittance Functions

    Directory of Open Access Journals (Sweden)

    D.R. Hughes

    2004-01-01

    Full Text Available A relatively overlooked factor in both global and local methods of health monitoring is the nonlinear stiffness of structures caused by the cycling of cracks and delaminations. Global methods of health monitoring use modal parameters or frequency response functions in an inverse procedure to quantify damage in structures with thick sections. Global approaches use fewer sensors that detect only significantly large damage in structures due to damage caused by transient vibration. However, local methods use Lamb wave propagation to detect small damage within a structure by an array of closely spaced sensors and actuators. Local methods also become more difficult to use on thick or non-homogeneous materials because wave propagation becomes complex. This paper develops a combined time series and wavelet analysis technique to improve damage detection in either thick, complex geometry, or non-homogeneous materials. A wavelet transmittance function (WTF is defined as the ratio of continuous wavelet transforms from the time responses at different locations on a structure. A new damage indicator was developed based upon wavelet transmittance function. The novelty of the method lies in the fact that a near real time inference about the damage and the approximate extent of damage can be drawn without historical data. A simulated model is illustrated to highlight the potential of the new damage indicator on a thick aluminum specimen. Then, experimental signal data from two sets of different experiments conducted on thick structures with a crack and a delamination were analyzed using the wavelet transmittance function to detect the presence and extent of the damages as reflected on the WTF maps. This paper mainly deals with the development of WTF and the associated damage indicator by analyzing the simulated and experimental sets of data.

  18. Highly re-entrant profiles in a thick photosensitive material for nanotechnology applications

    Science.gov (United States)

    Flack, Warren W.; Nguyen, Ha-Ai; Shaw, Mark; do Canto, Manny

    2006-03-01

    The requirements for highly specialized photosensitive materials for nanotechnology and Micro-Electro-Mechanical Systems (MEMS) applications are being driven by the rapid growth of consumer products incorporating these devices. These high volume consumer devices including accelerometers for air-bag sensors, biomedical sensors, optical switches and ink jet print heads. These applications all require ultra-thick photosensitive materials with highly controllable lithographic properties. For ink-jet print head applications, the lithography requirements include the formation of high aspect ratio structures with a negative (re-entrant) profile for nozzle formation. In order to form the required nozzle geometry for high resolution ink-jet printers, photosensitive materials need to be capable of providing up to 10 degree negative profiles at a film thickness of up to 25 microns. For consistent print dot size it is necessary to maintain excellent control and repeatability of the sidewall angle of the nozzle. Since this material remains on the substrate as a permanent part of the ink-jet print head, the mechanical and adhesive properties of the material are as important as the lithographic properties. This paper investigates modifications to an existing MicroChem epoxy-based SU8-4000 thick photoresist to generate highly re-entrant sidewall angles for next-generation high resolution ink-jet nozzle formation. Multiple versions of SU8-4000 with different levels of dye tuned for the exposure wavelength are exposed using a 1X lithography system optimized for thick photoresist processing. This stepper uses a combination of low numerical aperture, broadband exposure and large focus offsets for optimal processing of thick photosensitive materials. Basic photoresist characterization techniques in conjunction with cross sectional SEM analysis are used to establish lithographic capabilities for nozzle formation.

  19. Basalt Thickness in Mare Humorum: New Method and Results

    Science.gov (United States)

    Budney, C. J.; Lucey, P. G.

    1996-03-01

    Basalt thicknesses in mare basins have been determined using assumptions about the pre-mare topography of partly buried craters. Differences in those assumptions have led to a factor of two difference in mare thickness estimates. Further, knowledge of thickness is restricted to areas in which buried craters are present. We have shown that craters in the mare sometimes excavate highland material from below the mare cover. Using such craters, and assumptions about their depth of excavation, we can obtain independent estimates of basalt thickness. This method allows testing of pre-mare crater topography models employed in the buried crater method, adds significantly more data points for development of isopach maps, and allows determining of thickness of stratigraphic layers other than mare basalts such as melt sheets where compositional contrast is present.

  20. Influence of thickness on properties of plasticized oat starch films

    Directory of Open Access Journals (Sweden)

    Melicia Cintia Galdeano

    2013-08-01

    Full Text Available The aim of this study was to investigate the effect of thickness (between 80 and 120 µm on apparent opacity, water vapor permeability and mechanical properties (tensile and puncture of oat starch films plasticized with glycerol, sorbitol, glycerol:sorbitol mixture, urea and sucrose. Films were stored under 11, 57, 76 and 90% relative humidity (RH to study the mechanical properties. It was observed that the higher the thickness, the higher was the opacity values. Films without the plasticizer were more opaque in comparison with the plasticized ones. Glycerol:sorbitol films presented increased elongation with increasing thickness at all RH. Puncture force showed a strong dependence on the film thickness, except for the films plasticized with sucrose. In general, thickness did not affect the water permeability.

  1. Barium titanate thick films prepared by screen printing technique

    Directory of Open Access Journals (Sweden)

    Mirjana M. Vijatović

    2010-06-01

    Full Text Available The barium titanate (BaTiO3 thick films were prepared by screen printing technique using powders obtained by soft chemical route, modified Pechini process. Three different barium titanate powders were prepared: i pure, ii doped with lanthanum and iii doped with antimony. Pastes for screen printing were prepared using previously obtained powders. The thick films were deposited onto Al2O3 substrates and fired at 850°C together with electrode material (silver/palladium in the moving belt furnace in the air atmosphere. Measurements of thickness and roughness of barium titanate thick films were performed. The electrical properties of thick films such as dielectric constant, dielectric losses, Curie temperature, hysteresis loop were reported. The influence of different factors on electrical properties values was analyzed.

  2. Study on Thickness Effect of Three-Point-Bend Specimen

    Science.gov (United States)

    Kikuchi, Masanori; Ishihara, Takehito

    The thickness effect of a three-point-bend (3PB) specimen on dimple fracture behavior is studied experimentally and numerically. At first, fracture toughness tests were conducted using 3PB specimens of different thicknesses. Fracture toughness values and R-curves are obtained, and the thickness effect is discussed. Using scanning electron microscopy (SEM), dimple fracture surfaces are observed precisely. It is found that the thickness effect appears clearly in the void growth process. Finite element (FEM) analyses are conducted based on these experimental data. Using Gurson’s constitutive equation, the nucleation and growth of voids during the dimple fracture process are simulated. The distribution patterns of stress triaxiality and the crack growth process are obtained. The results show a good agreement with experimental ones qualitatively. The effects of specimen thickness on R-curves are explained well on the basis of these numerical simulations.

  3. Experimental investigation of effect of specimen thickness on fracture toughness of Al-TiC composites

    Directory of Open Access Journals (Sweden)

    M. S. Raviraj

    2016-07-01

    Full Text Available In this paper, the macro and micro-mechanical fracture behavior was studied for aluminum (Al6061 alloy matrix, reinforced with various proportions of TiC particles such as 3wt%, 5wt% and 7wt%. The Al6061-TiC metal matrix composites were produced by stir casting method to ensure uniform distribution of the TiC particulates in the Al matrix. The compact tension (CT specimens were machined according to ASTM E399 specifications to evaluate the fracture toughness for Al6061-TiC metal matrix composites. The CT specimens were machined for crack to width (a/W ratio of 0.5 and thickness to width (B/W ratios of 0.2 to 0.7 with an increment of 0.1. Load versus crack mouth opening displacement (CMOD data was plotted to estimate stress intensity factor KQ for various thicknesses of the specimen. The fracture toughness KIC was obtained by plotting stress intensity factor versus thickness to width ratios of specimen data. The fracture toughness of these composites varied between 16.4-19.2 MPa√m. Scanning Electron Microscope (SEM studies was made on the fractured surface of the specimens to understand the micro-mechanisms of failure involved in these composites. Void initiation is more significant in the matrix near the interface. The micro-cracks grow from these micro-voids and crack propagates by linking these micro cracks locating the crack path preferentially in the matrix adjacent to the interface indicating ductile fracture.

  4. Choroidal thickness after intravitreal ranibizumab injections for choroidal neovascularization

    Directory of Open Access Journals (Sweden)

    Ellabban AA

    2012-05-01

    Full Text Available Abdallah A Ellabban, Akitaka Tsujikawa, Ken Ogino, Sotaro Ooto, Kenji Yamashiro, Akio Oishi, Nagahisa YoshimuraDepartment of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, JapanPurpose: To study changes in choroidal thickness with ranibizumab treatment for choroidal neovascularization (CNV.Design: Prospective case series.Methods: This prospective study consisted of 60 CNV-affected eyes of 60 patients treated with intravitreal injections of ranibizumab using an on-demand protocol after an initial loading phase. The eyes studied included 20 with age-related macular degeneration (AMD, 20 with polypoidal choroidal vasculopathy (PCV, and 20 with myopic CNV. In the eyes with AMD and PCV, choroidal thickness at the fovea was measured with optical coherence tomography using enhanced depth imaging. In eyes with myopic CNV, the choroidal thickness was measured using standard optical coherence tomography without the enhanced depth imaging technique.Results: With ranibizumab treatment, central retinal thickness decreased significantly (P < 0.001 and visual acuity improved significantly (P < 0.001. However, central choroidal thickness (167.2 ± 108.3 µm showed no significant change at 1 month after the loading phase (165.2 ± 107.8 µm, P = 0.120 or at final examination (164.8 ± 107.7 µm, P = 0.115. At baseline, central retinal thickness in eyes with AMD was significantly greater that those with PCV (P = 0.005 or high myopia (P = 0.029. However, central choroidal thickness in eyes with myopic CNV was significantly thinner than in eyes with AMD (P < 0.001 or PCV (P < 0.001. In each type of disease, there was no significant change in central choroidal thickness with ranibizumab treatment.Conclusion: The effect of ranibizumab on the choroidal thickness is minimal, if any.Keywords: choroidal thickness, ranibizumab, optical coherence tomography

  5. The Sagittal Pelvic Thickness: A Determining Parameter for the Regulation of the Sagittal Spinopelvic Balance

    OpenAIRE

    2013-01-01

    Objective. To propose and validate a dimensional parameter, the sagittal pelvic thickness (SPT) (distance between the middle point of the upper sacral plate and the femoral heads axis, expressed as a ratio with the length of the upper plate of S1: (SPT/S1) for the analysis of the sagittal balance of the pelvispinal unit. Methods. The parameters were analysed on standing radiographic imaging and compared for normal, low back pain, children, and spondylolysis cases. Results. Values of SPT/S1 we...

  6. THICKNESS-SHEAR VIBRATION OF CIRCULAR CRYSTAL PLATE IN CYLINDRICAL SHELL AS PRESSURE SENSOR

    Institute of Scientific and Technical Information of China (English)

    HU Yuan-tai; CUI Zhi-jian; JIANG Shu-nong; YANG Jia-shi

    2006-01-01

    Based on the theory for small fields superposed on relatively larger fields in an electroelastic body, a theoretical analysis is performed on a circular plate thicknessshear crystal resonator sealed in a circular cylindrical shell for pressure measurement.A simple expression is obtained for pressure induced frequency shifts in the resonator,which is examined for design optimization. Numerical results show that the frequency shifts depend linearly on the pressure, and that a pressure sensor with a softer outer shell or a smaller thickness ratio of the crystal plate to the outer shell has higher sensitivity.

  7. Measuring the Average Thickness of a Plate Using a Bayesian Method and Free Vibration Data

    Science.gov (United States)

    2011-09-01

    form, the model is constructed with the implicit assumption that the corrosion is uniform. A more detailed model that included details of the pitting ...PROCEDURE The test specimen was a 0.76m by 0.60m (30” by 24”, 5:4 aspect ratio), 1.55mm (1/16”) thick 6061 -T6 aluminum plate. The density was...considering corrosion effect.” Marine Struc- tures, 21(4):402 – 419. [3] T. Nakai, H. Matsushita, N. Yamamoto, and H. Arai, 2004. “Effect of pitting

  8. Use of buffy coat thick films in detecting malaria parasites in patients with negative conventional thick films

    Institute of Scientific and Technical Information of China (English)

    Chatnapa Duangdee; Noppadon Tangpukdee; Srivicha Krudsood; Polrat Wilairatana

    2012-01-01

    Objective: To determine the frequency of malaria parasite detection from the buffy coat blood ilms by using capillary tube in falciparum malaria patients with negative conventional thick ilms. Methods: Thirty six uncomplicated falciparum malaria patients confirmed by conventional thick and thin films were included in the study. The patients were treated with artemisinin combination therapy at Hospital for Tropical Diseases, Bangkok, Thailand for 28 day. Fingerpricks for conventional blood films were conducted every 6 hours until negative parasitemia, then daily fingerpricks for parasite checks were conducted until the patients were discharged from hospital. Blood samples were also concurrently collected in 3 heparinized capillary tubes at the same time of fingerpricks for conventional blood films when the prior parasitemia was negative on thin films and parasitemia was lower than 50 parasites/200 white blood cells by thick film. The first negative conventional thick films were compared with buffy coat thick films for parasite identification.Results:Out of 36 patients with thick films showing negative for asexual forms of parasites, buffy coat films could detect remaining 10 patients (27.8%) with asexual forms of Plasmodium falciparum. Conclusions: The study shows that buffy coat thick films are useful and can detect malarial parasites in 27.8% of patients whose conventional thick films show negative parasitemia.

  9. Full-thickness skin grafts from eyelids to penis, plus split-thickness grafts in chronic balanitis xerotica obliterans.

    Science.gov (United States)

    Rudolph, R; Walther, P

    1997-02-01

    Balanitis xerotica obliterans is a progressive, sclerotic, constrictive scar-forming disease process of the penile prepuce that can involve the frenulum and urethral meatus. Full-thickness skin grafting from the upper eyelids supplemented with split-thickness skin grafting was successfully used in a patient to end a 57-year symptomatic course.

  10. On the Australian Bank Financial Ratio Analysis

    Institute of Scientific and Technical Information of China (English)

    张丽娜

    2011-01-01

    Financial ratios,despite some criticisms,are still used as a basis to evaluate a firm's performance,to make credit risk assessment decisions and classify firms into bankrupt and non-bankrupt groups.There are a great number of financial ratios which can be used for the evaluation of banks performance.Golin (2001) provides a list of over 80 ratios covering the major categories of capital,asset quality,profitability & efficiency,and liquidity & funding provides.

  11. Application of Performance Ratios in Portfolio Optimization

    OpenAIRE

    Aleš Kresta

    2015-01-01

    The cornerstone of modern portfolio theory was established by pioneer work of Harry Markowitz. Based on his mean-variance framework, Sharpe formulated his well-known Sharpe ratio aiming to measure the performance of mutual funds. The contemporary development in computer’s computational power allowed to apply more complex performance ratios, which take into account also higher moments of return probability distribution. Although these ratios were proposed to help the investors to improve the r...

  12. Choroidal and macular thickness changes induced by cataract surgery

    Directory of Open Access Journals (Sweden)

    Falcão MS

    2013-12-01

    Full Text Available Manuel S Falcão,1,2 Nuno M Gonçalves,2 Paulo Freitas-Costa,1,3 João B Beato,2 Amândio Rocha-Sousa,1,2 Ângela Carneiro,1,2 Elisete M Brandão,2 Fernando M Falcão-Reis1,21Department of Sense Organs, Faculty of Medicine, University of Porto, 2Department of Ophthalmology of Hospital de São João, 3Department of Anatomy, Faculty of Medicine, University of Porto, Porto, PortugalBackground: The aim of this study was to evaluate the effect of uneventful phacoemulsification on the morphology and thickness of the macula, the submacular choroid, and the peripapillary choroid.Methods: In 14 eyes from 14 patients, retinal macular thickness, choroidal submacular thickness, and choroidal peripapillary thickness were measured preoperatively and at one week and one month after phacoemulsification using enhanced depth imaging spectral domain optical coherence tomography. Changes in thickness of the different ocular tissues were evaluated.Results: There was a statistically significant increase in mean retinal macular thickness at one month. In horizontal scans, the mean increase was +8.67±6.75 µm (P<0.001, and in vertical scans, the mean increase was +8.80±7.07 µm (P=0.001. However, there were no significant changes in choroidal morphology in the submacular and peripapillary areas one month after surgery. In vertical scans, there was a nonsignificant increase in choroidal thickness (+4.21±20.2 µm; P=0.47 whilst in horizontal scans a nonsignificant decrease was recorded (−9.11±39.59 µm; P=0.41. In peripapillary scans, a nonsignificant increase in mean choroidal thickness was registered (+3.25±11.80 µm; P=0.36.Conclusion: Uncomplicated phacoemulsification induces nonpathologic increases in retinal macular thickness probably due to the inflammatory insult of the surgery; however these changes are not accompanied by significant changes in choroidal thickness. In the posterior segment, the morphologic response to the inflammatory insult of

  13. Back Work Ratio of Brayton Cycle

    Directory of Open Access Journals (Sweden)

    Malaver de la Fuente M.

    2010-07-01

    Full Text Available This paper analizes the existing relation between temperatures, back work ratio and net work of Brayton cycle, a cycle that describes gas turbine engines performance. The application of computational soft ware helps to show the influence of back work ratio or coupling ratio, compressor and turbine in let temperatures in an ideal thermodynamical cycle. The results lead to deduce that the maximum value reached in back work ratio will depend on the ranges of maximum and minimal temperatures of Brayton cycle.

  14. A ratio model of perceptual transparency.

    Science.gov (United States)

    Tommasi, M

    1999-12-01

    A ratio model of the achromatic transparency of a phenomenal surface on a bipartite background is proposed. The model asserts that transparency corresponds to the evaluation of the ratio of the lightness difference inside the transparent surface to the difference in reference lightness inside the background. It applies to both balanced and unbalanced transparency. The ratio model was compared experimentally with the previous perceptual model of achromatic transparency proposed by Metelli. Each model was tested by comparing the rated with the predicted transparency. Analysis shows that the ratio model provides better predictions of transparency than those provided by Metelli's model.

  15. Force dynamics in fixed-ratio schedules.

    Science.gov (United States)

    Pinkston, Jonathan W; McBee, Lindsey N

    2014-03-01

    Fixed-ratio schedules are widely used in behavioral research. Although fixed-ratio schedules often conjure up relationships to work and effort, little is known about effort-related measures in these schedules. Early research had shown that force and effort of operant behavior vary systematically during the execution of ratio schedules, and the goal of the present study was to revisit early research on force dynamics in fixed-ratio schedules. Four rats earned sucrose by pressing an isometric force transducer. Presses produced sucrose after ten or twenty responses. In general, the force of responses increased then decreased systematically across the ratio. The possibility that decreases in force during ratio execution was due to a trade-off with the differential reinforcement of short inter-response times (IRT) was investigated in an additional condition where sucrose was made available according to a tandem fixed-ratio 19 inter-response (IRT)> t schedule. The tandem IRT requirement did not eliminate decreasing trends in force across the ratio; unexpectedly, the tandem requirement did eliminate increases in force early in the ratio, which may reflect sequence-level organization operating in the control of force dynamics.

  16. Change in Tear Film Lipid Layer Thickness, Corneal Thickness, Volume and Topography after Superficial Cauterization for Conjunctivochalasis.

    Science.gov (United States)

    Chan, Tommy C Y; Ye, Cong; Ng, Paul K F; Li, Emmy Y M; Yuen, Hunter K L; Jhanji, Vishal

    2015-07-17

    We evaluated the change in tear film lipid layer thickness, corneal thickness, volume and topography after superficial cauterization of symptomatic conjunctivochalasis. Bilateral superficial conjunctival cauterization was performed in 36 eyes of 18 patients with symptomatic conjunctivochalasis. The mean age of patients (12 males, 6 females) was 68.6 ± 10.9 years (range: 44-83 years). Preoperatively, 28 eyes (77.8%) had grade 1 conjunctivochalasis, and 8 eyes (22.2%) had grade 2 conjunctivochalasis. At 1 month postoperatively, the severity of conjunctivochalasis decreased significantly (p corneal thickness, thinnest corneal thickness and corneal volume decreased significantly postoperatively (p corneal thickness and volume were observed after surgical correction of conjunctivochalasis.

  17. Geometrical Structures of Chemically Decomposed Thick and Thin Disk Populations

    Science.gov (United States)

    Kawata, D.; Brook, C. B.; Rahimi, A.; Gibson, B. K.

    2016-10-01

    We summarize the thick and thin disk formation commonly seen in cosmological N-body simulations. As suggested in Brook et al. (2004), a hierarchical clustering scenario causes multiple minor gas-rich mergers, and leads to the formation of a kinematically hot disk, thick disk population, at a high redshift. Once the mergers become less significant at a later epoch, the thin disk population starts building up. Because in this scenario the thick disk population forms intensively at high redshift through multiple gas-rich mergers, the thick disk population is compact and has systematically higher [α/Fe] abundance than the thin disk population. We discuss that the thick disk population would be affected by the formation of the thin disk and suffer from the radial migration, which helps the thick disk population to be observed in the solar neighborhood. In addition, we show that the current cosmological simulations also naturally predict that the thin disk population is flaring at the outer region. As shown in Rahimi et al. (2014), at high vertical height from the disk plane, the compact thick disk population (low metallicity and high [α/Fe]) is dominant in the inner region and the flaring thin disk population (high metallicity and low [α/Fe]) contributes more in the outer region. This helps to explain the positive radial metallicity gradient and negative radial [α/Fe] gradient observed at high vertical height in the Milky Way stellar disk.

  18. Gauging the Galactic thick disk with RR Lyrae stars

    Directory of Open Access Journals (Sweden)

    Cruz G.

    2012-02-01

    Full Text Available In this contribution we present results from the QUEST RR Lyrae Survey of the thick disk. The survey spans ~480 sq. deg. at low latitude |b| < 30°, with multi-epoch VRI observations, obtained with the QUEST-I camera at the 1m Jürgen Stock Schmidt telescope located at the National Astronomical Observatory of Venezuela. This constitutes the first deep RR Lyrae survey of the Galactic thick disk conducted at low galactic latitudes, covering simultaneously a large range in radial (8thick disk structural parameters from in situ RR Lyrae stars having accurate distances (errors <7% and individual reddenings derived from each star’s color curve at minimum light. Moreover, the use of RR Lyrae stars as tracers ensures negligible contamination from the Galactic thin disk. We find a thick disk mean scale height hZ = 0.94 ± 0.11kpc and scale length hR = 3.2 ± 0.4kpc, derived from the vertical and radial mean density profiles of RR Lyrae stars. We also find evidence of thick disk flaring and results that may suggest the thick disk radial density profile shows signs of antitruncation. We discuss our findings in the context of recent thick disk formation models.

  19. Peripapillary choroidal thickness in patients with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Ozcimen, Muammer; Sakarya, Yasar; Kurtipek, Ercan; Bekci, Taha T; Goktas, Sertan; Sakarya, Rabia; Yener, Halil I; Demir, Lutfi S; Erdogan, Erkan; Ivacik, Ismail S; Alpfidan, Ismail; Bukus, Abdulkadir

    2016-03-01

    To evaluate the peripapillary choroidal thickness of patients with chronic obstructive pulmonary disease (COPD) via enhanced depth imaging optical coherence tomography (EDI-OCT). A total of 80 patients with COPD (80 eyes) and 50 control subjects (50 eyes) were enrolled. Choroidal scans and the retinal nerve fiber layer (RNFL) thickness were obtained for all eyes using OCT. The average peripapillary choroidal thickness measurements of the COPD group (147.58 ± 53.53 μm) were lower than the control group (160.84 ± 44.73 μm) (p = 0.068). Inferior segment thicknesses were significantly thinner than the other segments (p choroidal thickness and RNFL thickness measurements of the COPD group were also lower than those of the control group (p = 0.111). Hypoxia in COPD seems to affect the choroidal thickness. Thinning of the choroid may be attributed to increased vascular resistance and reduced blood flow in patients with COPD. The possible effects of the disease to the eye may be clarified through the role of the choroidal vasculature in the blood supply of the anterior optic nerve head.

  20. THOR: Cloud Thickness from Off beam Lidar Returns

    Science.gov (United States)

    Cahalan, Robert F.; McGill, Matthew; Kolasinski, John; Varnai, Tamas; Yetzer, Ken

    2004-01-01

    Conventional wisdom is that lidar pulses do not significantly penetrate clouds having optical thickness exceeding about tau = 2, and that no returns are detectable from more than a shallow skin depth. Yet optically thicker clouds of tau much greater than 2 reflect a larger fraction of visible photons, and account for much of Earth s global average albedo. As cloud layer thickness grows, an increasing fraction of reflected photons are scattered multiple times within the cloud, and return from a diffuse concentric halo that grows around the incident pulse, increasing in horizontal area with layer physical thickness. The reflected halo is largely undetected by narrow field-of-view (FoV) receivers commonly used in lidar applications. THOR - Thickness from Off-beam Returns - is an airborne wide-angle detection system with multiple FoVs, capable of observing the diffuse halo, detecting wide-angle signal from which physical thickness of optically thick clouds can be retrieved. In this paper we describe the THOR system, demonstrate that the halo signal is stronger for thicker clouds, and validate physical thickness retrievals for clouds having z > 20, from NASA P-3B flights over the Department of Energy/Atmospheric Radiation Measurement/Southern Great Plains site, using the lidar, radar and other ancillary ground-based data.

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

    Directory of Open Access Journals (Sweden)

    Rachel Jane Sharkey

    2015-02-01

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

  2. Facial soft tissue thickness in North Indian adult population

    Directory of Open Access Journals (Sweden)

    Tanushri Saxena

    2012-01-01

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

  3. Effect of film thickness and filler properties on sulphuric acid permeation in various commercially available epoxy mortar coatings.

    Science.gov (United States)

    Valix, M; Mineyama, H; Chen, C; Cheung, W H; Shi, J; Bustamante, H

    2011-01-01

    The performance of various commercially available epoxy mortar coatings was compared by measuring their sulphuric acid diffusivity. Apparent diffusivities, which were measured gravimetrically, were found to be dependent on coating tortuosity. In composite materials like epoxy mortars, the tortuosity was determined by filler properties and polymer alignment. Tortuosity was found to depend on the filler size, their dispersion, filler aspect ratio and concentration. The order and greater alignment of polymer aggregates, which characterises thinner coatings effects higher tortuosity and thus lower permeabilities. The result is that sulphuric acid diffusivities were observed to increase with coating thickness, which challenges the notion that greater coating thicknesses provide greater protection or environmental barrier. The effect of film thickness and filler properties observed in this study has significant implications to the current selection of coatings and sewer protection.

  4. 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.

  5. Normative data of outer photoreceptor layer thickness obtained by software image enhancing based on Stratus optical coherence tomography images

    DEFF Research Database (Denmark)

    Christensen, U.C.; Krøyer, K.; Thomadsen, Jakob

    2008-01-01

    Aim: To present normative data of outer photoreceptor layer thickness obtained by a new semiautomatic image analysis algorithm operating on contrast-enhanced optical coherence tomography (OCT) images. Methods: Eight Stratus OCT3 scans from identical retinal locations from 25 normal eyes were...... registered and combined to form a contrast-enhanced average image. Utilising the vertical intensity gradients of the enhanced OCT images to demarcate retinal layers, thickness measurements of the outer photoreceptor- and retinal pigment epithelium layer (RPE-OScomplex) were obtained. Additionally...... in the superior macula 0.5-3 mm of the centre was significantly increased as compared with the corresponding inferior retina. In healthy subjects, the I-ratio-ONL was 1.06. Conclusions: Contrast-enhanced OCT images enable quantification of outer photoreceptor layer thickness, and normative values may help...

  6. Thickness and orientational design for a maximum stiff membrane

    Science.gov (United States)

    Pedersen, Pauli

    1990-01-01

    Recent results from sensitivity analysis for strain energy with anisotropic elasticity are applied to thickness and orientational design of laminated membranes. Primarily, the first order gradients of the total elastic energy are used in an optimality criteria based method. This traditional method is shown to give slow convergence with respect to design parameters, although the convergence of strain energy is very good. To get a deeper insight into this rather general characteristic, second order derivatives are included and it is shown how they can be obtained by first order sensitivity analysis. Examples of only thickness design, only orientational design, and combined thickness--orientational design are presented.

  7. Simultaneous orientation and thickness mapping in transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tyutyunnikov, Dmitry, E-mail: dmitry.tyutyunnikov@uni-ulm.de [Institute for Experimental Physics, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm (Germany); Burak Özdöl, V. [National Center for Electron Microscopy, MS 72-150 Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Koch, Christoph T. [Institute for Experimental Physics, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm (Germany)

    2015-03-15

    In this paper we introduce an approach for simultaneous thickness and orientation mapping of crystalline samples by means of transmission electron microscopy. We show that local thickness and orientation values can be extracted from experimental dark-field (DF) image data acquired at different specimen tilts. The method has been implemented to automatically acquire the necessary data and then map thickness and crystal orientation for a given region of interest. We have applied this technique to a specimen prepared from a commercial semiconductor device, containing multiple 22 nm technology transistor structures. The performance and limitations of our method are discussed and compared to those of other techniques available.

  8. Repulsive Casimir forces with finite-thickness slabs

    OpenAIRE

    Zhao, R.; Koschny, Th.; Economou, E. N.; C M Soukoulis

    2010-01-01

    We use the extended Lifshitz theory to study the behaviors of the Casimir forces between finite-thickness effective medium slabs. We first study the interaction between a semi-infinite Drude metal and a finite-thickness magnetic slab with or without substrate. For no substrate, the large distance $d$ dependence of the force is repulsive and goes as $1/d^5$; for the Drude metal substrate, a stable equilibrium point appears at an intermediate distance which can be tuned by the thickness of the ...

  9. On the book thickness of $k$-trees

    CERN Document Server

    Dujmović, Vida

    2009-01-01

    Every $k$-tree has book thickness at most $k+1$, and this bound is best possible for all $k\\geq3$. Vandenbussche et al. (2009) proved that every $k$-tree that has a smooth degree-3 tree decomposition with width $k$ has book thickness at most $k$. We prove this result is best possible for $k\\geq 4$, by constructing a $k$-tree with book thickness $k+1$ that has a smooth degree-4 tree decomposition with width $k$. This solves an open problem of Vandenbussche et al. (2009)

  10. Pelvic floor muscle thickness measured by perineal ultrasonography

    DEFF Research Database (Denmark)

    Bernstein, Inge Thomsen; Juul, N; Grønvall, S;

    1991-01-01

    Pelvic floor muscle thickness was assessed in nine healthy female physiotherapists by perineal sonography. All measurements were performed as triple-measurements. The aims were to assess the reliability of the measurements and to establish a reference material. The muscle thickness at rest...... and at contraction was 9.4 +/- 0.8 mm and 11.5 +/- 1.1 mm respectively (mean +/- SD). Contraction increased the thickness by 2.2 +/- 0.8 mm or 23 +/- 8%. The intra- and inter observer standard deviation of the estimate was in the range of 4-6%. In conclusion, we find the reliability of the measurements acceptable....

  11. A spectroscopic method for determining thickness of quartz wave plate

    Institute of Scientific and Technical Information of China (English)

    Weiwei Feng; Lihuang Lin; Ligang Chen; Huafeng Zhu; Ruxin Li; Zhizhan Xu

    2006-01-01

    A spectroscopic method to determine thickness of quartz wave plate is presented. The method is based on chromatic polarization interferometry. With the polarization-resolved transmission spectrum (PRTS)curve, the phase retardation of quartz wave plate can be determined at a wide spectral range from 200 to2000 nm obviously. Through accurate judgment of extreme points of PRTS curve at long-wave band, the physical thickness of quartz wave plates can be obtained exactly. We give a measuring example and the error analysis. It is found that the measuring precision of thickness is mainly determined by the spectral resolution of spectrometer.

  12. Thickness-dependent spontaneous dewetting morphology of ultrathin Ag films.

    Science.gov (United States)

    Krishna, H; Sachan, R; Strader, J; Favazza, C; Khenner, M; Kalyanaraman, R

    2010-04-16

    We show here that the morphological pathway of spontaneous dewetting of ultrathin Ag films on SiO2 under nanosecond laser melting is dependent on film thickness. For films with thickness h of 2 nm intermolecular forces, we have estimated the morphological transition thickness for the intermolecular forces for Ag on SiO2. The theory predictions agree well with observations for Ag. These results show that it is possible to form a variety of complex Ag nanomorphologies in a consistent manner, which could be useful in optical applications of Ag surfaces, such as in surface enhanced Raman sensing.

  13. 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.

  14. Corporate prediction models, ratios or regression analysis?

    NARCIS (Netherlands)

    Bijnen, E.J.; Wijn, M.F.C.M.

    1994-01-01

    The models developed in the literature with respect to the prediction of a company s failure are based on ratios. It has been shown before that these models should be rejected on theoretical grounds. Our study of industrial companies in the Netherlands shows that the ratios which are used in

  15. CCSSM Challenge: Graphing Ratio and Proportion

    Science.gov (United States)

    Kastberg, Signe E.; D'Ambrosio, Beatriz S.; Lynch-Davis, Kathleen; Mintos, Alexia; Krawczyk, Kathryn

    2013-01-01

    A renewed emphasis was placed on ratio and proportional reasoning in the middle grades in the Common Core State Standards for Mathematics (CCSSM). The expectation for students includes the ability to not only compute and then compare and interpret the results of computations in context but also interpret ratios and proportions as they are…

  16. Osmosis and Surface Area to Volume Ratio.

    Science.gov (United States)

    Barrett, D. R. B.

    1984-01-01

    Describes an experiment designed to help students understand the concepts of osmosis and surface area to volume ratio (SA:VOL). The task for students is to compare water uptake in different sizes of potato cubes and relate differences to their SA:VOL ratios. (JN)

  17. Key financial ratios can foretell hospital closures.

    Science.gov (United States)

    Lynn, M L; Wertheim, P

    1993-11-01

    An analysis of various financial ratios sampled from open and closed hospitals shows that certain leverage, liquidity, capital efficiency, and resource availability ratios can predict hospital closure up to two years in advance of the closure with an accuracy of nearly 75 percent.

  18. How to use and interpret hormone ratios.

    Science.gov (United States)

    Sollberger, Silja; Ehlert, Ulrike

    2016-01-01

    Hormone ratios have become increasingly popular throughout the neuroendocrine literature since they offer a straightforward way to simultaneously analyze the effects of two interdependent hormones. However, the analysis of ratios is associated with statistical and interpretational concerns which have not been sufficiently considered in the context of endocrine research. The aim of this article, therefore, is to demonstrate and discuss these issues, and to suggest suitable ways to address them. In a first step, we use exemplary testosterone and cortisol data to illustrate that one major concern of ratios lies in their distribution and inherent asymmetry. As a consequence, results of parametric statistical analyses are affected by the ultimately arbitrary decision of which way around the ratio is computed (i.e., A/B or B/A). We suggest the use of non-parametric methods as well as the log-transformation of hormone ratios as appropriate methods to deal with these statistical problems. However, in a second step, we also discuss the complicated interpretation of ratios, and propose moderation analysis as an alternative and oftentimes more insightful approach to ratio analysis. In conclusion, we suggest that researchers carefully consider which statistical approach is best suited to investigate reciprocal hormone effects. With regard to the hormone ratio method, further research is needed to specify what exactly this index reflects on the biological level and in which cases it is a meaningful variable to analyze.

  19. The Divine Ratio and Golden Rectangles.

    Science.gov (United States)

    Cooper, Martin

    1982-01-01

    The material examines aspects of Fibonacci and Lucas sequences, the generation of the Divine Ratio, and the nature of this ratio in golden rectangles, triangles, and figures made up of golden triangles. It is noted Lucas sequence is formed like Fibonacci but has one and three as the first elements. (Author/MP)

  20. Duty ratio of cooperative molecular motors.

    Science.gov (United States)

    Dharan, Nadiv; Farago, Oded

    2012-02-01

    Molecular motors are found throughout the cells of the human body and have many different and important roles. These micromachines move along filament tracks and have the ability to convert chemical energy into mechanical work that powers cellular motility. Different types of motors are characterized by different duty ratios, which is the fraction of time that a motor is attached to its filament. In the case of myosin II (a nonprocessive molecular machine with a low duty ratio), cooperativity between several motors is essential to induce motion along its actin filament track. In this work we use statistical mechanical tools to calculate the duty ratio of cooperative molecular motors. The model suggests that the effective duty ratio of nonprocessive motors that work in cooperation is lower than the duty ratio of the individual motors. The origin of this effect is the elastic tension that develops in the filament which is relieved when motors detach from the track.

  1. Equity Theory Ratios as Causal Schemas

    Directory of Open Access Journals (Sweden)

    Alexios Arvanitis

    2016-08-01

    Full Text Available Equity theory approaches justice evaluations based on ratios of exchange inputs to exchange outcomes. Situations are evaluated as just if ratios are equal and unjust if unequal. We suggest that equity ratios serve a more fundamental cognitive function than the evaluation of justice. More particularly, we propose that they serve as causal schemas for exchange outcomes, that is, they assist in determining whether certain outcomes are caused by inputs of other people in the context of an exchange process. Equality or inequality of ratios in this sense points to an exchange process. Indeed, Study 1 shows that different exchange situations, such as disproportional or balanced proportional situations, create perceptions of give-and-take on the basis of equity ratios. Study 2 shows that perceptions of justice are based more on communicatively accepted rules of interaction than equity-based evaluations, thereby offering a distinction between an attribution and an evaluation cognitive process for exchange outcomes.

  2. Luminal flow induces NADPH oxidase 4 translocation to the nuclei of thick ascending limbs.

    Science.gov (United States)

    Saez, Fara; Hong, Nancy J; Garvin, Jeffrey L

    2016-03-01

    Superoxide (O2 (-)) exerts its physiological actions in part by causing changes in gene transcription. In thick ascending limbs flow-induced O2 (-)production is mediated byNADPHoxidase 4 (Nox4) and is dependent on protein kinase C (PKC). Polymerase delta interacting protein 2 (Poldip2) increases Nox4 activity, but it is not known whether Nox4 translocates to the nucleus and whether Poldip2 participates in this process. We hypothesized that luminal flow causes Nox4 translocation to the nuclei of thick ascending limbs in aPKC-dependent process facilitated by Poldip2. To test our hypothesis, we studied the subcellular localization of Nox4 and Poldip2 using confocal microscopy and O2 (-)production in the absence and presence of luminal flow. Luminal flow increased the ratio of nuclear to cytoplasmic intensity of Nox4 (N/C) from 0.3 ± 0.1 to 0.7 ± 0.1 (P thick ascending limbs.

  3. The influence of scattered photons on the accurate determination of microcalcification thickness in digital mammography

    CERN Document Server

    Grabskii, V; Grabski, Varlen; Brandan, Maria-Ester

    2004-01-01

    Our interest has been to study the effect that scattered radiation has on contrast, signal-to-noise ratio and thickness reconstruction in digital mammographies. Using the GEANT code we have performed Monte-Carlo simulations of 25 kVp Mo/Mo photons, through a breast phantom which contains a 0.2-1.0 mm thick microcalcifications incident on a 20x106 $mm^{2}$ pixelized detector. The data have been analyzed assuming 6 different shapes of the incident beam: a 0.2x0.2 $mm^{2}$ ``narrow'' beam, 4 different 20 mm long scanning beams of various widths, and a 20x100 $mm^{2}$ beam with no scatter reduction mechanisms (NSR) . Since the image of a point depends on scattered photons which passed up to 2 cm away from the object (for 4 cm thick phantom), we identify the background definition as a main source of systematic uncertainty in the image quality analysis. We propose the use of two dimensional functions (a polynomial for the background and Gaussians for the signal) for total photon transmission description. Our main r...

  4. Motion Planning of Redundant Manipulators for Painting Uniform Thick Coating in Irregular Duct

    Directory of Open Access Journals (Sweden)

    Yan Chen

    2016-01-01

    Full Text Available The paper presents a motion planning method of redundant manipulator for painting uniform thick coating on the interior of irregular duct of some aircrafts. Discontinuous peripheral painting method is employed by analyzing the restrictions during painting the duct. For improving the longitudinal uniformity of thick coating, the interlacing painting method plans two sets of sweeping paths and an interlacing distance between the starting paths of the two times of painting. The interlacing distance and overlapping distance are optimized by establishing and analyzing the model of longitudinal uniformity. To enhance the transverse uniformity, sweeping speeds for curved surfaces are calculated by the ratio of transfer efficiency after the basic sweeping speed for the plane is determined. The intertwining method, minimizing the sum of the weighed distances between the duct centerline and key points of the manipulator links, is employed for the joint trajectory planning without collision. The simulation and experiment results show that the redundant manipulators can finish painting the internal surface of the irregular S-shaped duct without collision. The maximum relative deviation is 16.3% and the thicknesses of all measurement points satisfy the acceptance criteria of the factory.

  5. Facial dimensions, bite force and masticatory muscle thickness in preschool children with functional posterior crossbite

    Directory of Open Access Journals (Sweden)

    Paula Midori Castelo

    2008-03-01

    Full Text Available Posterior crossbite may affect craniofacial growth and development. Thus, this study aimed to associate facial dimensions (by standardized frontal photographs to masseter and anterior portion of the temporal muscle thickness (by ultrasonography and maximal bilateral bite force in 49 children with deciduous and early mixed dentitions. They were distributed in four groups: deciduous-normal occlusion (DNO, n = 15, deciduous-crossbite (DCB, n = 10, mixed-normal occlusion (MNO, n = 13 and mixed-crossbite (MCB, n = 11. Anterior facial height (AFH, bizygomatic width (FWB, and intergonial width (FWI were determined and associated with muscle thickness and bite force, applying Pearson’s coefficients and multiple logistic regression, with age, gender, body weight and height as the covariates. FWB and FWI were correlated positively with the masseter thickness, whereas AFH/FWB and AFH/FWI ratios had negative correlation, except in the DNO group. The correlation between AFH/FWB and bite force in the MCB group was significantly negative. A higher AFH/FWB in MNO and MCB led to a significantly higher probability for functional crossbite development. In the studied sample, it was observed that children in the early mixed dentition with a long-face trend showed lower bite force and higher probability to present functional posterior crossbite, without significant influence of the covariates.

  6. New Analysis for The FGM Thick Cylinders Under Combined Pressure and Temperature Loading

    Directory of Open Access Journals (Sweden)

    K. Abrinia

    2008-01-01

    Full Text Available An analytical solution for computing the radial and circumferential stresses in a FGM thick cylindrical vessel under the influence of internal pressure and temperature is presented in this paper. It has been assumed that the modulus of elasticity and thermal coefficient of expansion were varying through thickness of the FGM material according to a power law relationship. Nevertheless the value of the Poisson ratio was taken as constant throughout the material. In the analysis presented here the effect of non-homogeneity in FGM thick cylinder was implemented by choosing a dimensionless parameter, named β, which could be assigned an arbitrary value affecting the stresses in the cylinder. Using Maple 9.5, distribution of stresses in radial and circumferential directions for FGM cylinders under the influence of internal pressure and temperature gradient were obtained. Graphs of variations of stress versus radius of the cylinder were plotted for different values of β. Cases of pressure, temperature and combined loadings were considered separately. It was concluded that by changing the value of β, the properties of FGM could be so modified that the lowest stress levels were reached. The stresses which were produced in FGM and homogeneous material with the same boundary conditions were compared to obtain the optimum value of β.

  7. Could sex differences in white matter be explained by g ratio?

    Directory of Open Access Journals (Sweden)

    Tomas Paus

    2009-09-01

    Full Text Available Recent studies with magnetic resonance imaging suggest that age-related changes in white matter during male adolescence may indicate an increase in g ratio wherein the radial growth of an axon outpaces a corresponding increase in myelin thickness. We review the original Rushton (1951 model where a g ratio of ~0.6 represents an optimal relationship between the axon and fibre diameters vis-à-vis conduction velocity, and point out evidence indicating slightly higher g ratio in large-diameter fibres. We estimate that fibres with a diameter larger than 9.6 µm will have a relatively thinner myelin sheath, and brains with increasingly larger proportions of such large-diameter fibres will have progressively lower concentration of myelin. We conclude by pointing out possible implications of “suboptimal” g ratio for the emergence of “disconnection” disorders, such as schizophrenia, in late adolescence.

  8. OBTAINING THE CRITICAL DRAW RATIO OF DRAW RESONANCE IN MELT SPINNING FOR POWER LAW POLYMER FLUIDS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A direct difference method has been developed for Non-Newtonian power law fluids to solve the simultaneous non-linear partial differential equations of melt spinning,and to determine the critical draw ratio for draw resonance.The results show that for shear thin fluids,the logarithm of the critical draw ratio has a well defined linear relationship with the power index for isothermal and uniform tension melt spinning.When the power index approaches zero,the critical draw ratio points at unity,indicating no melt spinning can be processed stably for such fluids.For shear thick fluids.the critical draw ratio increases in a more rapid Way with increasing the power index.

  9. Vapor-melt Ratio in Laser Fine Cutting of Slot Arrays

    Science.gov (United States)

    Xuyue, Wang; Qingxuan, Meng; Renke, Kang; Wenji, Xu; Dongming, Guo; Lianji, Wang

    2011-05-01

    In order to improve cut quality for slot arrays, a new method of laser fine cutting under the consideration of the ratio of vapor to melt is presented. Laser cutting of 6063 aluminum alloy sheet, 0.5 mm in thickness, was carried out on a JK701H Nd:YAG pulse laser cutting system. The effects of vapor-melt ratio on kerf width, surface roughness and recast layer were studied which relate cutting qualities. Observation on the cut samples with different vapor-melt ratios (0.687, 1.574, 3.601 varied with laser power increasing, and 1.535, 3.601, 7.661 with decreasing of beam cutting speed) shows that high vapor-melt ratio improves laser cut quality clearly. Kerf width 0.2 mm of smooth area on kerf top area and thickness 2.03 μm of recast layer are obtained. No dross was found on the kerf bottom and the percentage of the smooth area is up to 40% out of whole kerf side. The research on vapor-melt ratio provides a deeper understanding of laser cutting and improves laser cut quality effectively.

  10. A semi-automated method for measuring thickness and white matter integrity of the corpus callosum

    Directory of Open Access Journals (Sweden)

    S Andronikou

    2012-12-01

    distance along the midline contour. The following parameters are measurable: midline CC thickness; midline FA; fibre volume for each hemisphere (represented as a left/right ratio centred on zero and mean fibre FA for each hemisphere (also represented as a left/right ratio centred on zero. Results. The tool proved successful in measuring and plotting CC midline thickness and FA, but was not sensitive for peripheral white matter lesions. Conclusions. The technique successfully determined values of CC midline thickness, FA and interhemispheric differences. Future research will determine normal values for age and compare CC thickness with peripheral white matter volume loss in large groups of patients, using the semiautomated technique.

  11. Quantification of retinal layer thickness changes in acute macular neuroretinopathy

    DEFF Research Database (Denmark)

    Munk, Marion R; Beck, Marco; Kolb, Simone

    2017-01-01

    PURPOSE: To quantitatively evaluate retinal layer thickness changes in acute macular neuroretinopathy (AMN). METHODS: AMN areas were identified using near-infrared reflectance (NIR) images. Intraretinal layer segmentation using Heidelberg software was performed. The inbuilt ETDRS -grid was moved ...

  12. Modeled Thickness of the Overburden Geomodel Unit (obthk_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The obthk_f grid represents the modeled thickness of the Overburden geomodel unit at a 500 foot resolution. It is one grid of a geomodel that consists of eleven...

  13. Study of pipe thickness loss using a neutron radiography method

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Abdul Aziz; Wahab, Aliff Amiru Bin [Universiti Tenaga Nasional, Jalan IKRAM-UNITEN, 43000 Kajang, Selangor (Malaysia); Yazid, Hafizal B.; Ahmad, Megat Harun Al Rashid B. Megat; Jamro, Rafhayudi B.; Azman, Azraf B.; Zin, Muhamad Rawi Md; Idris, Faridah Mohamad [Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

    2014-02-12

    The purpose of this preliminary work is to study for thickness changes in objects using neutron radiography. In doing the project, the technique for the radiography was studied. The experiment was done at NUR-2 facility at TRIGA research reactor in Malaysian Nuclear Agency, Malaysia. Test samples of varying materials were used in this project. The samples were radiographed using direct technique. Radiographic images were recorded using Nitrocellulose film. The films obtained were digitized to processed and analyzed. Digital processing is done on the images using software Isee!. The images were processed to produce better image for analysis. The thickness changes in the image were measured to be compared with real thickness of the objects. From the data collected, percentages difference between measured and real thickness are below than 2%. This is considerably very low variation from original values. Therefore, verifying the neutron radiography technique used in this project.

  14. Thickness of a Europan ice shell from impact crater simulations.

    Science.gov (United States)

    Turtle, E P; Pierazzo, E

    2001-11-09

    Several impact craters on Jupiter's satellite Europa exhibit central peaks. On the terrestrial planets, central peaks consist of fractured but competent rock uplifted during cratering. Therefore, the observation of central peaks on Europa indicates that an ice layer must be sufficiently thick that the impact events did not completely penetrate it. We conducted numerical simulations of vapor and melt production during cratering of water ice layers overlying liquid water to estimate the thickness of Europa's icy crust. Because impacts disrupt material well beyond the zone of partial melting, our simulations put a lower limit on ice thickness at the locations and times of impact. We conclude that the ice must be more than 3 to 4 kilometers thick.

  15. Characteristics of shell thickness in a slab continuous casting mold

    Institute of Scientific and Technical Information of China (English)

    Di-feng Wu; Shu-sen Cheng; Zi-jian Cheng

    2009-01-01

    The key to reduce shell breakout in the continuous casting process is to control shell thickness in the mold.A numerical simulation on the turbulent flow and heat transfer coupled with solidification in the slab mold using the volume of fluid (VOF) model and the enthalpy-porosity scheme was conducted and the emphasis was put upon the flow effect on the shell thickness profiles in longitudinal and transverse directions.The results show that the jet acts a stronger impingement on the shell of narrow face,which causes a zero-increase of shell thickness in a certain range near the impingement point.The thinnest shell on the slab cross-section locates primarily in the center of the narrow face,and secondly near the comer of the wide face.Nozzle optimization can obviously increase the shell thickness and make it more uniform.

  16. on THICKNESS OF COPPER (|) OXIDE (Cu2"O) SOLAR CELL

    African Journals Online (AJOL)

    thickness of copper oxides solar ce[[s prepared 63/ thermaf oxidation method The sampfes were oxidized at di_';§'erent oxidation temperatures and time. The diflerent oxidation ... observed that the later was relatively high. Adrianus (1978).

  17. One-cm-thick Si detector at LHe temperature

    Energy Technology Data Exchange (ETDEWEB)

    Braggio, C. [Dipartimento di Fisica, Universita di Ferrara, Via Saragat 1, 44100 Ferrara (Italy)], E-mail: braggio@pd.infn.it; Bressi, G. [INFN, Sez. di Pavia, Via Bassi 6, 27100 Pavia (Italy); Carugno, G. [INFN, Sez. di Padova, Via Marzolo 8, 35131 Padova (Italy); Galeazzi, G. [Laboratori Nazionali di Legnaro, Via dell' Universita 1, 35020 Legnaro (Italy); Serafin, A. [Dipartimento di Fisica, Universita di Padova, Via Marzolo 8, 35131 Padova (Italy)

    2007-10-11

    A silicon p-i-n diode of thickness 1 cm has been studied experimentally at liquid helium temperature. This preliminary study is aimed at the construction of a much bigger detector to detect low energy neutrino events.

  18. GLERL Great Lakes Ice Thickness Data Base, 1966-1979

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During the winters of 1965/66 through 1976/77, NOAA/Great Lakes Environmental Research Laboratory (GLERL) collected weekly ice thickness and stratigraphy data at up...

  19. Sediment Thickness--Pigeon Point to South Monterey Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the sediment-thickness map of the Pigeon Point to South Monterey Bay, California, region. The raster data file is included in...

  20. Thickness Effect of Micro Speaker Copper Coil Fabrication Process

    Directory of Open Access Journals (Sweden)

    F. L. AYAT

    2011-07-01

    Full Text Available This paper present the advantage of using electroplating for making the thick layer of copper over the sputtering. The purpose of this paper is to fabricate the copper coil for microspeaker. The design and simulation of this copper coil shows that the 15 um thickness is needed. In order to fabricate this coil, copper plating is used. The electro-deposition process is well suited to make films of metals such as copper, gold and nickel. The films can be made in any thickness from ~1 µm to >100 µm. The deposition is best controlled when used with an external electrical potentiostate. However, it requires electrical contact to the substrate when immersed in the liquid bath. In any process, the surface of the substrate must have an electrically conducting coating before the deposition can be done. The result of this experimental research shows the easy and cheap way to fabricate the thick layer of copper for microspeacker fabrication.