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Sample records for significant microstructural differences

  1. Microstructure of Pharmaceutical Semicrystalline Dispersions: The Significance of Polymer Conformation.

    Science.gov (United States)

    Van Duong, Tu; Goderis, Bart; Van Humbeeck, Jan; Van den Mooter, Guy

    2018-02-05

    The microstructure of pharmaceutical semicrystalline solid dispersions has attracted extensive attention due to its complexity that might result in the diversity in physical stability, dissolution behavior, and pharmaceutical performance of the systems. Numerous factors have been reported that dictate the microstructure of semicrystalline dispersions. Nevertheless, the importance of the complicated conformation of the polymer has never been elucidated. In this study, we investigate the microstructure of dispersions of polyethylene glycol and active pharmaceutical ingredients by small-angle X-ray scattering and high performance differential scanning calorimetry. Polyethylene glycol with molecular weight of 2000 g/mol (PEG2000) and 6000 g/mol (PEG6000) exhibited remarkable discrepancy in the lamellar periodicity in dispersions with APIs which was attributed to the differences in their folding behavior. The long period of PEG2000 always decreased upon aging-induced exclusion of APIs from the interlamellar region of extended chain crystals whereas the periodicity of PEG6000 may decrease or increase during storage as a consequence of the competition between the drug segregation and the lamellar thickening from nonintegral-folded into integral-folded chain crystals. These processes were in turn significantly influenced by the crystallization tendency of the pharmaceutical compounds, drug-polymer interactions, as well as the dispersion composition and crystallization temperature. This study highlights the significance of the polymer conformation on the microstructure of semicrystalline systems that is critical for the preparation of solid dispersions with consistent and reproducible quality.

  2. Microstructure of Tablet-Pharmaceutical Significance, Assessment, and Engineering.

    Science.gov (United States)

    Sun, Changquan Calvin

    2017-05-01

    To summarize the microstructure - property relationship of pharmaceutical tablets and approaches to improve tablet properties through tablet microstructure engineering. The main topics reviewed here include: 1) influence of material properties and manufacturing process parameters on the evolution of tablet microstructure; 2) impact of tablet structure on tablet properties; 3) assessment of tablet microstructure; 4) development and engineering of tablet microstructure. Microstructure plays a decisive role on important pharmaceutical properties of a tablet, such as disintegration, drug release, and mechanical strength. Useful information on mechanical properties of a powder can be obtained from analyzing tablet porosity-pressure data. When helium pycnometry fails to accurately measure true density of a water-containing powder, non-linear regression of tablet density-pressure data is a useful alternative method. A component that is more uniformly distributed in a tablet generally exerts more influence on the overall tablet properties. During formulation development, it is highly recommended to examine the relationship between any property of interest and tablet porosity when possible. Tablet microstructure can be engineered by judicious selection of formulation composition, including the use of the optimum solid form of the drug and appropriate type and amount of excipients, and controlling manufacturing process.

  3. Reaustenitisation of steels with different initial microstructures

    International Nuclear Information System (INIS)

    Garcia-Caballero, F.; Capdevila, C.; San Martin, D.; Garcia-de Andre, C.

    2004-01-01

    During the last years, physical mathematical models concerning continuous cooling and isothermal phase transformations valid for a wide range of steel have been attained. However, the modelling of continuous heating transformations has not undergone the same development than in cooling. This investigation concerns with the study and Modelization of continuous heating phase transformations to study the process which is generally referred to as austenitisation of the steel. Therefore, our main aim is to describe those processes which control the non-isothermal formation of austenite in steel with initial microstructures of ferrite and/or pearlite. (Author) 10 refs

  4. ''Geopolymers": same basic chemistry, different microstructures

    Directory of Open Access Journals (Sweden)

    Palomo, A.

    2004-09-01

    Full Text Available The present paper describes the effect of certain working variables on the microstructural evolution of oven-dried, alkali-activated fly ash. The results show that the main reaction product in the activation process (in all the systems studied is an amorphous aluminosilicate gel with a three-dimensional structure. Nonetheless, the type and concentration of the activator used as well as the natural ageing of the materials and origin of the prime materials were also found to have a substantial impact on microstructural development in the "geopolymers " synthesised, particularly from the morphological standpoint.

    Este trabajo describe el efecto de determinadas variables de trabajo sobre la evolución microestructural de sistemas basados en cenizas volantes térmica y alcalínamente activadas. Los resultados demuestran que el principal producto de reacción en el proceso de activación (en todos los sistemas estudiados es un aluminosilicato amorfo con características de gel y con estructura tridimensional. Sin embargo el tipo y la concentración del activador usado, así como el envejecimiento natural de los materiales y el origen diferente de las materias primas han demostrado también ser variables que afectan sustancialmente al desarrollo microestructural de los ''geopolimeros" sintetizados, especialmente desde el punto de vista morfológico.

  5. Microstructural defects in EUROFER 97 after different neutron irradiation conditions

    Directory of Open Access Journals (Sweden)

    Christian Dethloff

    2016-12-01

    Full Text Available Characterization of irradiation induced microstructural evolution is essential for assessing the applicability of structural steels like the Reduced Activation Ferritic/Martensitic steel EUROFER 97 in upcoming fusion reactors. In this work Transmission Electron Microscopy (TEM is used to determine the defect microstructure after different neutron irradiation conditions. In particular dislocation loops, voids and precipitates are analyzed concerning defect nature, density and size distribution after irradiation to 15 dpa at 300 °C in the mixed spectrum High Flux Reactor (HFR. New results are combined with previously obtained data from irradiation in the fast spectrum BOR-60 reactor (15 and 32 dpa, 330 °C, which allows for assessment of dose and dose rate effects on the aforementioned irradiation induced defects and microstructural characteristics.

  6. Behavior and microstructural changes in different tungsten-based materials under pulsed plasma loading

    Directory of Open Access Journals (Sweden)

    M. Vilémová

    2016-12-01

    Full Text Available In this study, morphological, microstructural and phase changes of four types of tungsten materials after exposure to dense deuterium plasma were examined. The microstructures of the prepared materials mutually differ by the porosity, grain size and phase content. It was found that inherent porosity of sintered materials leads to a specific mechanism of erosion and might be a significant source of dust in the case of materials with higher porosity. Further, a preferential erosion of the dispersed particles by melting and evaporation and subsequent formation of thin film on the surface of W-Y2O3 was described as well.

  7. Microstructure and physicochemical properties reveal differences between high moisture buffalo and bovine Mozzarella cheeses.

    Science.gov (United States)

    Nguyen, Hanh T H; Ong, Lydia; Lopez, Christelle; Kentish, Sandra E; Gras, Sally L

    2017-12-01

    Mozzarella cheese is a classical dairy product but most research to date has focused on low moisture products. In this study, the microstructure and physicochemical properties of both laboratory and commercially produced high moisture buffalo Mozzarella cheeses were investigated and compared to high moisture bovine products. Buffalo and bovine Mozzarella cheeses were found to significantly differ in their microstructure, chemical composition, organic acid and proteolytic profiles but had similar hardness and meltability. The buffalo cheeses exhibited a significantly higher ratio of fat to protein and a microstructure containing larger fat patches and a less dense protein network. Liquid chromatography mass spectrometry detected the presence of only β-casein variant A2 and a single β-lactoglobulin variant in buffalo products compared to the presence of both β-casein variants A1 and A2 and β-lactoglobulin variants A and B in bovine cheese. These differences arise from the different milk composition and processing conditions. The differences in microstructure and physicochemical properties observed here offer a new approach to identify the sources of milk used in commercial cheese products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Scaling relations between trabecular bone volume fraction and microstructure at different skeletal sites.

    Science.gov (United States)

    Räth, Christoph; Baum, Thomas; Monetti, Roberto; Sidorenko, Irina; Wolf, Petra; Eckstein, Felix; Matsuura, Maiko; Lochmüller, Eva-Maria; Zysset, Philippe K; Rummeny, Ernst J; Link, Thomas M; Bauer, Jan S

    2013-12-01

    In this study, we investigated the scaling relations between trabecular bone volume fraction (BV/TV) and parameters of the trabecular microstructure at different skeletal sites. Cylindrical bone samples with a diameter of 8mm were harvested from different skeletal sites of 154 human donors in vitro: 87 from the distal radius, 59/69 from the thoracic/lumbar spine, 51 from the femoral neck, and 83 from the greater trochanter. μCT images were obtained with an isotropic spatial resolution of 26μm. BV/TV and trabecular microstructure parameters (TbN, TbTh, TbSp, scaling indices ( and σ of α and αz), and Minkowski Functionals (Surface, Curvature, Euler)) were computed for each sample. The regression coefficient β was determined for each skeletal site as the slope of a linear fit in the double-logarithmic representations of the correlations of BV/TV versus the respective microstructure parameter. Statistically significant correlation coefficients ranging from r=0.36 to r=0.97 were observed for BV/TV versus microstructure parameters, except for Curvature and Euler. The regression coefficients β were 0.19 to 0.23 (TbN), 0.21 to 0.30 (TbTh), -0.28 to -0.24 (TbSp), 0.58 to 0.71 (Surface) and 0.12 to 0.16 (), 0.07 to 0.11 (), -0.44 to -0.30 (σ(α)), and -0.39 to -0.14 (σ(αz)) at the different skeletal sites. The 95% confidence intervals of β overlapped for almost all microstructure parameters at the different skeletal sites. The scaling relations were independent of vertebral fracture status and similar for subjects aged 60-69, 70-79, and >79years. In conclusion, the bone volume fraction-microstructure scaling relations showed a rather universal character. © 2013.

  9. Impact load-induced micro-structural damage and micro-structure associated mechanical response of concrete made with different surface roughness and porosity aggregates

    International Nuclear Information System (INIS)

    Erdem, Savaş; Dawson, Andrew Robert; Thom, Nicholas Howard

    2012-01-01

    The relationship between the nature of micro damage under impact loading and changes in mechanical behavior associated with different microstructures is studied for concretes made with two different coarse aggregates having significant differences mainly in roughness and porosity — sintered fly ash and uncrushed gravel. A range of techniques including X-ray diffraction, digital image analysis, mercury porosimetry, X-ray computed tomography, laser surface profilometry and scanning electron microscopy were used to characterize the aggregates and micro-structures. The concrete prepared with lightweight aggregates was stronger in compression than the gravel aggregate concrete due to enhanced hydration as a result of internal curing. In the lightweight concrete, it was deduced that an inhomogeneous micro-structure led to strain incompatibilities and consequent localized stress concentrations in the mix, leading to accelerated failure. The pore structure, compressibility, and surface texture of the aggregates are of paramount importance for the micro-cracking growth.

  10. Catalytic Activity Control via Crossover between Two Different Microstructures

    KAUST Repository

    Zhou, Yuheng

    2017-09-08

    Metal nanocatalysts hold great promise for a wide range of heterogeneous catalytic reactions, while the optimization strategy of catalytic activity is largely restricted by particle size or shape control. Here, we demonstrate that a reversible microstructural control through the crossover between multiply-twinned nanoparticle (MTP) and single crystal (SC) can be readily achieved by solvent post-treatment on gold nanoparticles (AuNPs). Polar solvents (e.g. water, methanol) direct the transformation from MTP to SC accompanied by the disappearance of twinning and stacking faults. A reverse transformation from SC to MTP is achieved in non-polar solvent (e.g. toluene) mixed with thiol ligands. The transformation between two different microstructures is directly observed by in-situ TEM and leads to a drastic modulation of catalytic activity towards the gas-phase selective oxidation of alcohols. There is a quasi-linear relationship between TOFs and MTP concentrations. Based on the combined experimental and theoretical investigations of alcohol chemisorption on these nanocatalysts, we propose that the exposure of {211}-like microfacets associated with twin boundaries and stack faults accounts for the strong chemisorption of alcohol molecules on MTP AuNPs and thus the exceptionally high catalytic activity.

  11. Strength and microstructure of IPS Empress 2 glass-ceramic after different treatments.

    Science.gov (United States)

    Oh, S C; Dong, J K; Lüthy, H; Schärer, P

    2000-01-01

    This investigation was designed to determine whether heat pressing and/or simulated heat treatments affect the flexure strength and microstructure of the lithium disilicate glass-ceramic of the IPS Empress 2 system. Four groups of the lithium disilicate glass-ceramic were prepared as follows: group 1 = as-received material; group 2 = heat-pressed material; group 3 = heat-pressed and stimulated initial heat-treated material; and group 4 = heat-pressed and simulated heat-treated material with full firings for a final restoration. Three-point bending tests and scanning electron microscopy (SEM) analysis were conducted. The flexure strength of group 2 was significantly higher than that of group 1. However, there were no significant differences in strength among groups 2, 3, and 4, or between groups 1 and 4. The SEM micrographs of the lithium disilicate glass-ceramic showed a closely packed, multidirectionally interlocking microstructure of numerous lithium disilicate crystals protruding from the glass matrix. The crystals in the glass matrix of the heat-pressed materials (groups 2, 3, and 4) were a little more homogeneous and about 2 times bigger than those of the as-received material (group 1). These changes of the microstructure were greatest between groups 1 and 2. However, there were no marked differences among groups 2, 3, and 4. Although there were significant increases in the strength and some changes of the microstructure after the heat-pressing operation, the combination of heat pressing and simulated subsequent heat treatments did not produce an increase of strength of IPS Empress 2 glass-ceramic.

  12. Microstructure and mechanical properties of hard zone in friction stir welded X80 pipeline steel relative to different heat input

    Energy Technology Data Exchange (ETDEWEB)

    Aydin, Hakan, E-mail: hakanay@uludag.edu.tr [Engineering and Architecture Faculty, Mechanical Engineering Department, Uludag University, 16059 Gorukle-Bursa (Turkey); Nelson, Tracy W. [Mechanical Engineering Department, Brigham Young University, 435 CTB, Provo, UT 84602 (United States)

    2013-12-01

    The study was conducted to investigate the microstructure and mechanical properties of the hard zone in friction stir welded X80 pipeline steel at different heat inputs. Microstructural analysis of the welds was carried out using optical microscopy, transmission electron microscopy, and microhardness. Heat input during friction stir welding process had a significant influence on the microstructure and mechanical properties in the hard zone along the advancing side of the weld nugget. Based on the results, the linear relationships between heat input and post-weld microstructures and mechanical properties in the hard zone of friction stir welded X80 steels were established. It can be concluded that with decrease in heat input the bainitic structure in the hard zone becomes finer and so hard zone strength increases.

  13. Microstructure and mechanical properties of hard zone in friction stir welded X80 pipeline steel relative to different heat input

    International Nuclear Information System (INIS)

    Aydin, Hakan; Nelson, Tracy W.

    2013-01-01

    The study was conducted to investigate the microstructure and mechanical properties of the hard zone in friction stir welded X80 pipeline steel at different heat inputs. Microstructural analysis of the welds was carried out using optical microscopy, transmission electron microscopy, and microhardness. Heat input during friction stir welding process had a significant influence on the microstructure and mechanical properties in the hard zone along the advancing side of the weld nugget. Based on the results, the linear relationships between heat input and post-weld microstructures and mechanical properties in the hard zone of friction stir welded X80 steels were established. It can be concluded that with decrease in heat input the bainitic structure in the hard zone becomes finer and so hard zone strength increases

  14. [Effect of thermal cycling on surface microstructure of different light-curing composite resins].

    Science.gov (United States)

    Lv, Da; Liu, Kai-Lei; Yao, Yao; Zhang, Wei-Sheng; Liao, Chu-Hong; Jiang, Hong

    2015-04-01

    To evaluate the effect of thermal cycling on surface microstructure of different light-curing composite resins. A nanofilled composite (Z350) and 4 microhybrid composites (P60, Z250, Spectrum, and AP-X) were fabricated from lateral to center to form cubic specimens. The lateral surfaces were abrased and polished before water storage and 40 000 thermal cycles (5/55 degrees celsius;). The mean surface roughness (Ra) were measured and compared before and after thermal cycling, and the changes of microstructure were observed under scanning electron microscope (SEM). Significant decreases of Ra were observed in the composites, especially in Spectrum (from 0.164±0.024 µm to 0.140±0.017 µm, Presins, and fissures occurred on Z350 following the thermal cycling. Water storage and thermal cycling may produce polishing effect on composite resins and cause fissures on nanofilled composite resins.

  15. Catalytic Activity Control via Crossover between Two Different Microstructures

    KAUST Repository

    Zhou, Yuheng; Zhu, Yihan; Wang, Zhi-Qiang; Zou, Shihui; Ma, Guicen; Xia, Ming; Kong, Xueqian; Xiao, Liping; Gong, Xue-Qing; Fan, Jie

    2017-01-01

    microstructural control through the crossover between multiply-twinned nanoparticle (MTP) and single crystal (SC) can be readily achieved by solvent post-treatment on gold nanoparticles (AuNPs). Polar solvents (e.g. water, methanol) direct the transformation from

  16. The dimensionality of between-person differences in white matter microstructure in old age.

    Science.gov (United States)

    Lövdén, Martin; Laukka, Erika Jonsson; Rieckmann, Anna; Kalpouzos, Grégoria; Li, Tie-Qiang; Jonsson, Tomas; Wahlund, Lars-Olof; Fratiglioni, Laura; Bäckman, Lars

    2013-06-01

    Between-person differences in white matter microstructure may partly generalize across the brain and partly play out differently for distinct tracts. We used diffusion-tensor imaging and structural equation modeling to investigate this issue in a sample of 260 adults aged 60-87 years. Mean fractional anisotropy and mean diffusivity of seven white matter tracts in each hemisphere were quantified. Results showed good fit of a model positing that individual differences in white matter microstructure are structured according to tracts. A general factor, although accounting for variance in the measures, did not adequately represent the individual differences. This indicates the presence of a substantial amount of tract-specific individual differences in white matter microstructure. In addition, individual differences are to a varying degree shared between tracts, indicating that general factors also affect white matter microstructure. Age-related differences in white matter microstructure were present for all tracts. Correlations among tract factors did not generally increase as a function of age, suggesting that aging is not a process with homogenous effects on white matter microstructure across the brain. These findings highlight the need for future research to examine whether relations between white matter microstructure and diverse outcomes are specific or general. Copyright © 2011 Wiley Periodicals, Inc.

  17. Individual differences in fornix microstructure and body mass index.

    Directory of Open Access Journals (Sweden)

    Claudia Metzler-Baddeley

    Full Text Available The prevalence of obesity and associated health conditions is increasing in the developed world. Obesity is related to atrophy and dysfunction of the hippocampus and hippocampal lesions may lead to increased appetite and weight gain. The hippocampus is connected via the fornix tract to the hypothalamus, orbitofrontal cortex, and the nucleus accumbens, all key structures for homeostatic and reward related control of food intake. The present study employed diffusion MRI tractography to investigate the relationship between microstructural properties of the fornix and variation in Body Mass Index (BMI, within normal and overweight ranges, in a group of community-dwelling older adults (53-93 years old. Larger BMI was associated with larger axial and mean diffusivity in the fornix (r = 0.64 and r = 0.55 respectively, relationships that were most pronounced in overweight individuals. Moreover, controlling for age, education, cognitive performance, blood pressure and global brain volume increased these correlations. Similar associations were not found in the parahippocampal cingulum, a comparison temporal association pathway. Thus, microstructural changes in fornix white matter were observed in older adults with increasing BMI levels from within normal to overweight ranges, so are not exclusively related to obesity. We propose that hippocampal-hypothalamic-prefrontal interactions, mediated by the fornix, contribute to the healthy functioning of networks involved in food intake control. The fornix, in turn, may display alterations in microstructure that reflect weight gain.

  18. Evaluation of microstructural difference in low alloy steel (SA508 CI.3) by magnetic measurements

    International Nuclear Information System (INIS)

    Chi, Se Hwan; Park, Duck Gun; Hong, Jun Hwa; Kuk, Il Hium; Song, Sook Hyang; Shur, Dong Soo

    1997-01-01

    Magnetic measurements on SA 508 Cl. 3 low alloy reactor pressure vessel (RPV) steels of three different refining processes were conducted to prepare baseline magnetic properties for future comparison with that of irradiated one and to examine the correlation between microstructures and magnetic parameters. TEM(transmission electron microscopy) on thin films and carbon replications were performed for microstructural investigation, and microhardness, tensile and fracture toughness tests were conducted for mechanical properties measurement. Barkhausen noise analysis was conducted and hysteresis parameters were measured. Microstructure, mechanist and magnetic properties were interpreted together to explore their inter-relationship. Also the applicability of a magnetic nondestructive evaluation method for monitoring fine microstructural changes in low alloy steels of complicated microstructure was examined. The results showed that, of all magnetic parameters, Barkhausen noise amplitudes show consistent change with microstructure (grain size, carbide microstructure, lath width) and hardness of the materials. For monitoring microstructural and mechanical property changes of low alloy steel under service environment of reactor pressure vessel steels, Barkhausen noise amplitude and coercivity appear to be as key magnetic parameters useful for nondestructive evaluation.

  19. Microstructural characterization of ODS ferritic steels at different processing stages

    Energy Technology Data Exchange (ETDEWEB)

    Gil, E., E-mail: egil@ceit.es; Ordás, N.; García-Rosales, C.; Iturriza, I., E-mail: iiturriza@ceit.es

    2015-10-15

    Highlights: • ODS ferritic stainless steel produced by new route without mechanical alloying. • Fully dense ferritic stainless steels containing Y and Ti were obtained by HIPping. • Y and Ti-rich precipitates prevent grain growth during heat treatment up to 1320 °C. • HIPping at 1220 °C dissolves the metastable oxides on PPBs. - Abstract: Nanostructured Oxide Dispersion Strengthened Reduced Activation Ferritic Stainless Steels (ODS RAF) are promising structural materials for fusion reactors, due to their ultrafine microstructure and the presence of a dispersion of Y–Ti–O nanoclusters that provide excellent creep strength at high temperatures (up to 750 °C). The traditional powder metallurgical route to produce these steels is based on Gas Atomization (GA) + Mechanical Alloying (MA) + HIP + ThermoMechanical Treatments (TMTs). Recently, alternative methods have arisen to avoid the MA step. In line with this new approach, ferritic stainless steel powders were produced by gas atomization and HIPped, after adjusting their oxygen, Y and Ti contents to form Y–Ti–O nanoclusters during subsequent heat treatments. The microstructure of as-HIPped steels mainly consists of ferrite grains, Y–Ti precipitates, carbides and oxides on Prior Particle Boundaries (PPBs). Post-HIP heat treatments performed at high temperatures (1270 and 1300 °C) evaluated the feasibility of achieving a complete dissolution of the oxides on PPBs and a precipitation of ultrafine Ti- and Y-rich oxides in the Fe14Cr2W matrix. FEG-SEM with extensive EDS analysis was used to characterize the microstructure of the atomized powders and the ODS-RAF specimens after HIP consolidation and post-HIP heat treatments. A deeper characterization of atomized powder was carried out by TEM.

  20. Study of surface plasma coating of 4340 steel with different microstructure for high temperature use

    International Nuclear Information System (INIS)

    Carrer, Isabela Reis; Abdalla, Antonio Jorge; Barboza, Miguel Justino Ribeiro; Suzuki, Paulo Atsushi

    2010-01-01

    This paper has as main objective the formation of different microstructures by the specific heat treatments and applies the plasma thermochemical treatments to increase surface hardness. These two types of treatments will be evaluated in creep mechanical properties in steel 4340 for aeronautic uses. It will be evaluated, at first, the influence of heat treatments that changes the material microstructure. It was prepared specimen with three kinds of different microstructures (ferritic- perlitic, bainitic and martensitic), have been formed by the different heat treatments. After that, part of specimen will be submitted to plasma coating to evaluate the influence of this kind of surface treatment on creep properties. To better understand the microstructure and the relations between his properties, it was realized microscopic analyses, hardness tests and X-ray diffraction. (author)

  1. COMPUTER PROCESSING OF MICROSTRUCTURES OF IRON WITH DIFFERENT INCLUSIONS AMOUNTS OF LAMELLAR AND SPHERICAL GRAPHITE

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2013-01-01

    Full Text Available Based on cast iron microstructures with different amounts of impurities of plastic and nodular graphite given in CCITT 3443-87 “Cast iron with various forms of graphite. Methods for determining the structure “shows the possibilities of automated quantitative analysis of microstructures SG2, PG4, PG6, PG10, PG12 (Plastic Box and SHG2, SHG4, SHG6, SHG10, SHG12 (spheroidal graphite, which allows the development of methods for the determination of impurities of plastic and spherical graphite according to the microstructures image under the light microscope.

  2. No differences in brain microstructure between young KIBRA-C carriers and non-carriers.

    Science.gov (United States)

    Hu, Li; Xu, Qunxing; Li, Jizhen; Wang, Feifei; Xu, Xinghua; Sun, Zhiyuan; Ma, Xiangxing; Liu, Yong; Wang, Qing; Wang, Dawei

    2018-01-02

    KIBRA rs17070145 polymorphism is associated with variations in memory function and the microstructure of related brain areas. Diffusion kurtosis imaging (DKI) as an extension of diffusion tensor imaging that can provide more information about changes in microstructure, based on the idea that water diffusion in biological tissues is heterogeneous due to structural hindrance and restriction. We used DKI to explore the relationship between KIBRA gene polymorphism and brain microstructure in young adults. We recruited 100 healthy young volunteers, including 53 TT carriers and 47 C allele carriers. No differences were detected between the TT homozygotes and C-allele carriers for any diffusion and kurtosis parameter. These results indicate KIBRA rs17070145 polymorphism likely has little or no effect on brain microstructure in young adults.

  3. Does the casting mode influence microstructure, fracture and properties of different metal ceramic alloys?

    Science.gov (United States)

    Bauer, José Roberto de Oliveira; Grande, Rosa Helena Miranda; Rodrigues-Filho, Leonardo Eloy; Pinto, Marcelo Mendes; Loguercio, Alessandro Dourado

    2012-01-01

    The aim of the present study was to evaluate the tensile strength, elongation, microhardness, microstructure and fracture pattern of various metal ceramic alloys cast under different casting conditions. Two Ni-Cr alloys, Co-Cr and Pd-Ag were used. The casting conditions were as follows: electromagnetic induction under argon atmosphere, vacuum, using blowtorch without atmosphere control. For each condition, 16 specimens, each measuring 25 mm long and 2.5 mm in diameter, were obtained. Ultimate tensile strength (UTS) and elongation (EL) tests were performed using a Kratos machine. Vickers Microhardness (VM), fracture mode and microstructure were analyzed by SEM. UTS, EL and VM data were statistically analyzed using ANOVA. For UTS, alloy composition had a direct influence on casting condition of alloys (Wiron 99 and Remanium CD), with higher values shown when cast with Flame/Air (p casting condition" influenced the EL and VM results, generally presenting opposite results, i.e., alloy with high elongation value had lower hardness (Wiron 99), and casting condition with the lowest EL values had the highest VM values (blowtorch). Both factors had significant influence on the properties evaluated, and prosthetic laboratories should select the appropriate casting method for each alloy composition to obtain the desired property.

  4. Testing the Difference of Correlated Agreement Coefficients for Statistical Significance

    Science.gov (United States)

    Gwet, Kilem L.

    2016-01-01

    This article addresses the problem of testing the difference between two correlated agreement coefficients for statistical significance. A number of authors have proposed methods for testing the difference between two correlated kappa coefficients, which require either the use of resampling methods or the use of advanced statistical modeling…

  5. A Study on the Microstructural Evolution of a Low Alloy Steel by Different Shot Peening Treatments

    Directory of Open Access Journals (Sweden)

    Juan González

    2018-03-01

    Full Text Available Recent studies have shown that severe shot peening can be categorized as a severe plastic deformation surface treatment that is able to strongly modify the microstructure of the surface layer of materials, by both increasing the dislocation density and introducing a large number of defects that define new grain boundaries and form ultrafine structure. In this work, conventional shot peening and severe shot peening treatments were applied to 39NiCrMo3 steel samples. The samples were characterized in terms of microstructure, surface roughness, microhardness, residual stresses, and surface work-hardening as a function of surface coverage. Particular attention was focused on the analysis of the microstructure to assess the evolution of grain size from the surface to the inner material to capture the gradient microstructure. Severe shot peening proved to cause a more remarkable improvement of the general mechanical characteristics compared to conventional shot peening; more significant improvement was associated with the microstructural alteration induced by the treatment. Our datas provide a detailed verification of the relationship between shot peening treatment parameters and the microstructure evolution from the treated surface to the core material.

  6. Microstructural Evolution During Cold Rolling and Subsequent Annealing in Low-Carbon Steel with Different Initial Microstructures

    Science.gov (United States)

    Ogawa, Toshio; Dannoshita, Hiroyuki; Maruoka, Kuniaki; Ushioda, Kohsaku

    2017-08-01

    Microstructural evolution during cold rolling and subsequent annealing of low-carbon steel with different initial microstructures was investigated from the perspective of the competitive phenomenon between recrystallization of ferrite and reverse phase transformation from ferrite to austenite. Three kinds of hot-rolled sheet specimens were prepared. Specimen P consisted of ferrite and pearlite, specimen B consisted of bainite, and specimen M consisted of martensite. The progress of recovery and recrystallization of ferrite during annealing was more rapid in specimen M than that in specimens P and B. In particular, the recrystallized ferrite grains in specimen M were fine and equiaxed. The progress of ferrite-to-austenite phase transformation during intercritical annealing was more rapid in specimen M than in specimens P and B. In all specimens, the austenite nucleation sites were mainly at high-angle grain boundaries, such as those between recrystallized ferrite grains. The austenite distribution was the most uniform in specimen M. Thus, we concluded that fine equiaxed recrystallized ferrite grains were formed in specimen M, leading to a uniform distribution of austenite.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  8. Microstructural Changes within the Basal Ganglia Differ between Parkinson Disease Subtypes.

    Science.gov (United States)

    Nagae, Lidia M; Honce, Justin M; Tanabe, Jody; Shelton, Erika; Sillau, Stefan H; Berman, Brian D

    2016-01-01

    Diffusion tensor imaging (DTI) of the substantia nigra has shown promise in detecting and quantifying neurodegeneration in Parkinson disease (PD). It remains unknown, however, whether differences in microstructural changes within the basal ganglia underlie PD motor subtypes. We investigated microstructural changes within the basal ganglia of mild to moderately affected PD patients using DTI and sought to determine if microstructural changes differ between the tremor dominant (TD) and postural instability/gait difficulty (PIGD) subtypes. Fractional anisotropy, mean diffusivity, radial, and axial diffusivity were obtained from bilateral caudate, putamen, globus pallidus, and substantia nigra of 21 PD patients (12 TD and 9 PIGD) and 20 age-matched healthy controls. T-tests and ANOVA methods were used to compare PD patients, subtypes, and controls, and Spearman correlations tested for relationships between DTI and clinical measures. We found our cohort of PD patients had reduced fractional anisotropy within the substantia nigra and increased mean and radial diffusivity within the substantia nigra and globus pallidus compared to controls, and that changes within those structures were largely driven by the PIGD subtype. Across all PD patients fractional anisotropy within the substantia nigra correlated with disease stage, while in PIGD patients increased diffusivity within the globus pallidus correlated with disease stage and motor severity. We conclude that PIGD patients have more severely affected microstructural changes within the substantia nigra compared to TD, and that microstructural changes within the globus pallidus may be particularly relevant for the manifestation of the PIGD subtype.

  9. Test for the statistical significance of differences between ROC curves

    International Nuclear Information System (INIS)

    Metz, C.E.; Kronman, H.B.

    1979-01-01

    A test for the statistical significance of observed differences between two measured Receiver Operating Characteristic (ROC) curves has been designed and evaluated. The set of observer response data for each ROC curve is assumed to be independent and to arise from a ROC curve having a form which, in the absence of statistical fluctuations in the response data, graphs as a straight line on double normal-deviate axes. To test the significance of an apparent difference between two measured ROC curves, maximum likelihood estimates of the two parameters of each curve and the associated parameter variances and covariance are calculated from the corresponding set of observer response data. An approximate Chi-square statistic with two degrees of freedom is then constructed from the differences between the parameters estimated for each ROC curve and from the variances and covariances of these estimates. This statistic is known to be truly Chi-square distributed only in the limit of large numbers of trials in the observer performance experiments. Performance of the statistic for data arising from a limited number of experimental trials was evaluated. Independent sets of rating scale data arising from the same underlying ROC curve were paired, and the fraction of differences found (falsely) significant was compared to the significance level, α, used with the test. Although test performance was found to be somewhat dependent on both the number of trials in the data and the position of the underlying ROC curve in the ROC space, the results for various significance levels showed the test to be reliable under practical experimental conditions

  10. Study creep in 4340 steels with different microstructure and plasma carbon nitridation processing

    International Nuclear Information System (INIS)

    Abdalla, A.J.; Carrer, I.R.; Barboza, M.J.R.; Baggio-Scheid, V.H.; Moura Neto, C.; Reis, D.A.P.

    2010-01-01

    From the AISI 4340 bars specimens were made-for-test of creep, they were subjected to different heat treatments for the formation of multiphase microstructures. After this initial treatment, a lot of the specimens were tested in creep. One second batch of specimens was treated with a plasma carbonitriding, and later, were also tested. The carbonitriding layer and microstructure were characterized with X-ray analysis, laser confocal microscopy and hardness testing. Tests showed that the hardness in the steel was reduced due to thermochemical treatment at 500 deg C. We observed variation in creep behavior due to different microstructures formed. After the plasma treatment, there was a considerable reduction in the rate of creep and an increase in the time required for fracture. (author)

  11. Microstructure and Corrosion Resistance Property of a Zn-AI-Mg Alloy with Different Solidification Processes

    Directory of Open Access Journals (Sweden)

    Jiang Guang-rui

    2017-01-01

    Full Text Available Zn-Al-Mg alloy coating attracted much attention due to its high corrosion resistance properties, especially high anti-corrosion performance at the cut edge. As the Zn-Al-Mg alloy coating was usually produced by hot-dip galvanizing method, solidification process was considered to influence its microstructure and corrosion properties. In this work, a Zn-Al-Mg cast alloy was melted and cooled to room temperature with different solidification processes, including water quench, air cooling and furnace cooling. Microstructure of the alloy with different solidification processes was characterized by scanning electron microscopy (SEM. Result shows that the microstructure of the Zn-Al-Mg alloy are strongly influenced by solidification process. With increasing solidification rate, more Al is remained in the primary crystal. Electrochemical analysis indicates that with lowering solidification rate, the corrosion current density of the Zn-Al-Mg alloy decreases, which means higher corrosion resistance.

  12. One arm exercise induces significant interarm diastolic blood pressure difference.

    Science.gov (United States)

    Hong, Dezhi; Wang, Jiwei; Su, Hai; Xu, Jingsong; Liu, Yanna; Peng, Qiang; Wang, Lijuan

    2011-06-01

    This study is designed to investigate the inducing effect of one arm exercise on interarm difference (IAD) in the blood pressure (BP). Fifty healthy young participants were included in the study. Three-minute exercises of the right arm elbow flexion and extension were performed. The bilateral brachial BP was simultaneously measured with two automatic BP measurement devices before (basic) and immediately 0, 5, 10, 15, 20, and 30 min after exercise. The absolute difference in the systolic BP (SBP) and diastolic BP (DBP) between the left and right BP of at least 10 mmHg was recognized as sIAD and dIAD. The baseline data of the SBP and DBP in left and right arms revealed no significant difference (SBP: 110 ± 10 vs. 111 ± 11 mmHg; DBP: 66 ± 8 vs. 66 ± 9 mmHg, both not significant). The prevalence of dIAD was 2% at the baseline. However, this prevalence increased to 80% at 0 min, as right arm exercise induced the right DBP decrease and left DBP increase, and then the prevalence decreased gradually within a 30-min recovery period. The prevalence of sIAD was zero at the baseline and the maximal prevalence was 8% during the 20-min postexercise period. One arm exercise can lead to a significant IAD in DBP. Any arm exercise should be avoided before BP measurement.

  13. Significance of perfectionism in understanding different forms of insomnia

    Directory of Open Access Journals (Sweden)

    Totić-Poznanović Sanja

    2012-01-01

    Full Text Available Introduction. Studies consistently show a connection between perfectionism as a multidimensional construct with various psychological and psychopathological states and characteristics. However, studies that analyze the connection between this concept and sleep disturbances, especially modalities of insomnia, are rare. Objective. The aim of this study was to examine whether dimensions of perfectionism can explain different forms of insomnia; difficulties initiating sleep (insomnia early, difficulties during the sleep (insomnia middle, waking in early hours of the morning (insomnia late and dissatisfaction with sleep quality (subjective insomnia. Methods. The sample consisted of 254 students of the School of Medicine in Belgrade. Predictive significance of nine perfectionism dimensions, measured by Frost’s and Hewitt’s and Flett’s scales of multi-dimensional perfectionism, related to four modalities of insomnia, measured by a structured questionnaire, was analyzed by multiple linear regression method. Results. Perfectionism dimensions are significant predictors of each of the tested forms of insomnia. Doubt about actions significantly predicts initial insomnia; to other-oriented perfectionism in the negative pole and socially prescribed perfectionism underlie the difficulties during the sleep, while organization and parental criticism underlie late insomnia. Significant predictors of subjective insomnia are personal standards and organization and to other-oriented perfectionism on the negative pole. Three of nine analyzed dimensions were not confirmed as significant; concern over mistakes, parental expectations and self-oriented perfectionism. Conclusion. Various aspects of perfectionism can be considered as a vulnerability factor for understanding some forms of insomnia. Out of all forms of insomnia tested, perfectionism as the personality trait proved to be the most significant for understanding subjective insomnia.

  14. 3D Scaffolds with Different Stiffness but the Same Microstructure for Bone Tissue Engineering.

    Science.gov (United States)

    Chen, Guobao; Dong, Chanjuan; Yang, Li; Lv, Yonggang

    2015-07-29

    A growing body of evidence has shown that extracellular matrix (ECM) stiffness can modulate stem cell adhesion, proliferation, migration, differentiation, and signaling. Stem cells can feel and respond sensitively to the mechanical microenvironment of the ECM. However, most studies have focused on classical two-dimensional (2D) or quasi-three-dimensional environments, which cannot represent the real situation in vivo. Furthermore, most of the current methods used to generate different mechanical properties invariably change the fundamental structural properties of the scaffolds (such as morphology, porosity, pore size, and pore interconnectivity). In this study, we have developed novel three-dimensional (3D) scaffolds with different degrees of stiffness but the same 3D microstructure that was maintained by using decellularized cancellous bone. Mixtures of collagen and hydroxyapatite [HA: Ca10(PO4)6(OH)2] with different proportions were coated on decellularized cancellous bone to vary the stiffness (local stiffness, 13.00 ± 5.55 kPa, 13.87 ± 1.51 kPa, and 37.7 ± 19.6 kPa; bulk stiffness, 6.74 ± 1.16 kPa, 8.82 ± 2.12 kPa, and 23.61 ± 8.06 kPa). Microcomputed tomography (μ-CT) assay proved that there was no statistically significant difference in the architecture of the scaffolds before or after coating. Cell viability, osteogenic differentiation, cell recruitment, and angiogenesis were determined to characterize the scaffolds and evaluate their biological responses in vitro and in vivo. The in vitro results indicate that the scaffolds developed in this study could sustain adhesion and growth of rat mesenchymal stem cells (MSCs) and promote their osteogenic differentiation. The in vivo results further demonstrated that these scaffolds could help to recruit MSCs from subcutaneous tissue, induce them to differentiate into osteoblasts, and provide the 3D environment for angiogenesis. These findings showed that the method we developed can build scaffolds with

  15. Microstructural stress relaxation mechanics in functionally different tendons.

    Science.gov (United States)

    Screen, H R C; Toorani, S; Shelton, J C

    2013-01-01

    Tendons experience widely varying loading conditions in vivo. They may be categorised by their function as either positional tendons, which are used for intricate movements and experience lower stress, or as energy storage tendons which act as highly stressed springs during locomotion. Structural and compositional differences between tendons are thought to enable an optimisation of their properties to suit their functional environment. However, little is known about structure-function relationships in tendon. This study adopts porcine flexor and extensor tendon fascicles as examples of high stress and low stress tendons, comparing their mechanical behaviour at the micro-level in order to understand their stress relaxation response. Stress-relaxation was shown to occur predominantly through sliding between collagen fibres. However, in the more highly stressed flexor tendon fascicles, more fibre reorganisation was evident when the tissue was exposed to low strains. By contrast, the low load extensor tendon fascicles appears to have less capacity for fibre reorganisation or shearing than the energy storage tendon, relying more heavily on fibril level relaxation. The extensor fascicles were also unable to sustain loads without rapid and complete stress relaxation. These findings highlight the need to optimise tendon repair solutions for specific tendons, and match tendon properties when using grafts in tendon repairs. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  16. Comparison of fatigue crack initiation behavior in different microstructures of TC21 titanium alloy

    Directory of Open Access Journals (Sweden)

    Tan Changsheng

    2018-01-01

    Full Text Available Cyclic heterogeneous deformation, slip characteristics and crack nucleation with different microstructures, such as bimodal microstructure (BM and fine lamellar microstructure (FLM in TC21 alloy (Ti-6Al-2Sn-2Zr-3Mo-1Cr-2Nb-0.1Si, were systematically investigated and analyzed during high cycle fatigue at room temperature. The results demonstrated that the FLM microstructure possesses higher high-cycle fatigue strength than those of the BM one. For BM, the heterogeneous plastic deformation existed within the different large primary α phase, such as equiaxed primary α and primary α lath. The cracks at interfaces and slip bands easily coalesce with each other to form large cracks in BM. However, the α laths with similar morphology and size (nanosize distributed uniformly in FLM and could relatively deform homogeneously in micro-region, which delayed the initiation of the fatigue crack. Based on the electron-backscattered diffraction (EBSD analysis, it found that the strain was nonuniformly distributed in BM, however, it is relatively homogeneous in FLM. Moreover, lots of straight cracks are parallel and along single intrusions within the β grain which delays the coalescence of cracks.

  17. Explanation of significant differences for the TNX groundwater operable unit

    International Nuclear Information System (INIS)

    Palmer, E.R.

    1997-01-01

    This Explanation of Significant Differences (ESD) is being issued by the Department of Energy (DOE), the lead agency for the Savannah River Site (SRS), with concurrence by the Environmental Protection Agency-Region IV (EPA) and South Carolina Department of Health and Environmental Control (SCDHEC) to announce changes in the interim remediation strategy selected for the TNX Groundwater Operable Unit. The TNX Area is located adjacent to the Savannah River in the southwestern portion of SRS. The remedy selected in the Interim Record of Decision (IROD) to achieve the interim action goals was the Hybrid Groundwater Corrective Action (HGCA). The HGCA consisted of a recirculation well system and an air stripper with a series of groundwater extraction wells. The original remediation strategy needs to be modified because the recirculation well system was determined to be ineffective in this area due to geological factors and the nature of the contamination

  18. Research on Performance and Microstructure of Sewage Pipe Mortar Strengthened with Different Anti-Corrosion Technologies

    Science.gov (United States)

    Mu, Song; Zhou, Huaxin; Shi, Liang; Liu, Jianzhong; Cai, Jingshun; Wang, Feng

    2017-10-01

    Mostly urban underground sewage is the acidic corrosion environment with a high concentration of aggressive ions and microbe, which resulted in performance deterioration and service-life decrease of sewage concrete pipe. In order to effectively protect durability of the concrete pipe, the present paper briefly analysed the main degradation mechanism of concrete pipe attacked by urban underground sewage, and proposed that using penetrating and strengthening surface sealer based on inorganic chemistry. In addition, using index of compressive strength, weight loss and appearance level to investigate the influence of the sealer on corrosion resistance of mortar samples after different dry-wet cycles. Besides, comparative research on effect of the sealer, aluminate cement and admixture of corrosion resistance was also addressed. At last, the SEM technology was used to reveal the improvement mechanism of different technologies of corrosion resistance. The results indicated that the sealer and aluminate cement can significantly improve corrosion resistance of mortar. Besides, the improvement effect can be described as the descending order: the penetrating and strengthening surface sealer > aluminate cement > admixture of corrosion resistance. The mortar sample treated with the sealer displayed the condensed and sound microstructure which proved that the sealer can improve the corrosion resistance to urban underground sewage.

  19. Microstructure and wettability of root canal dentine and root canal filling materials after different chemical irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Antonijevic, Djordje; Milovanovic, Petar [Laboratory for Anthropology, Institute for Anatomy, Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Brajkovic, Denis [Department of Dentistry, Faculty of Medical Sciences, University of Kragujevac, Kragujevac (Serbia); Ilic, Dragan [Department of Restorative Medicine, School of Dental Medicine, University of Belgrade, Belgrade (Serbia); Hahn, Michael; Amling, Michael [Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Lottestr. 55A, 22529 Hamburg (Germany); Rakocevic, Zlatko [Laboratory for Atomic Physics, Institute for Nuclear Science “Vinca”, University of Belgrade, Belgrade (Serbia); Djuric, Marija [Laboratory for Anthropology, Institute for Anatomy, Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Busse, Björn, E-mail: b.busse@uke.uni-hamburg.de [Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Lottestr. 55A, 22529 Hamburg (Germany)

    2015-11-15

    Graphical abstract: - Highlights: • Different irrigation solutions and disinfectants were used for treatment of root canal dentine and gutta-percha points. • Materials surface characteristics were assessed using quantitative backscattered electron imaging, reference point indentation, and contact angle analyzer. • The most significant differences in mineralization, indentation, and adhesive outcomes were observed after ethylenediaminetetraacetic acid treatment. • Irrigation solutions confer to superior sealing ability of endodontic filling materials. • Micromechanical characteristics of dentine after irrigation are considerable reduced. - Abstract: The objective of this study was to determine the effects of various irrigation solutions on root canal dentine and gutta-percha surface properties. In addition, the effects of disinfectant chemicals on the wettability and surface morphological properties of the filling materials were evaluated. Ethylenediaminetetraacetic acid (EDTA), citric acid, and ozone were employed as irrigation solutions for dentine and gutta-percha treatment. Thereafter, the samples’ microstructure, degree of mineralization, and mechanical properties were assessed by means of quantitative backscattered electron imaging (qBEI) and reference point indentation (RPI). A contact angle analyzer was used to measure adhesion on the tested materials. Here, EDTA had the most significant affect on both the mechanical properties and the adhesive behavior of dentine. Citric acid did not affect dentine wettability, whereas the indentation properties and the mineralization were reduced. Similar effects were observed when ozone was used. The dentinal tubules were significantly widened in citric acid compared to the ozone group. EDTA causes considerable micromechanical surface alteration of dentine and gutta-percha, but represents the best option in clinical cases where a high adhesiveness of the filling materials is desired.

  20. Microstructure and wettability of root canal dentine and root canal filling materials after different chemical irrigation

    International Nuclear Information System (INIS)

    Antonijevic, Djordje; Milovanovic, Petar; Brajkovic, Denis; Ilic, Dragan; Hahn, Michael; Amling, Michael; Rakocevic, Zlatko; Djuric, Marija; Busse, Björn

    2015-01-01

    Graphical abstract: - Highlights: • Different irrigation solutions and disinfectants were used for treatment of root canal dentine and gutta-percha points. • Materials surface characteristics were assessed using quantitative backscattered electron imaging, reference point indentation, and contact angle analyzer. • The most significant differences in mineralization, indentation, and adhesive outcomes were observed after ethylenediaminetetraacetic acid treatment. • Irrigation solutions confer to superior sealing ability of endodontic filling materials. • Micromechanical characteristics of dentine after irrigation are considerable reduced. - Abstract: The objective of this study was to determine the effects of various irrigation solutions on root canal dentine and gutta-percha surface properties. In addition, the effects of disinfectant chemicals on the wettability and surface morphological properties of the filling materials were evaluated. Ethylenediaminetetraacetic acid (EDTA), citric acid, and ozone were employed as irrigation solutions for dentine and gutta-percha treatment. Thereafter, the samples’ microstructure, degree of mineralization, and mechanical properties were assessed by means of quantitative backscattered electron imaging (qBEI) and reference point indentation (RPI). A contact angle analyzer was used to measure adhesion on the tested materials. Here, EDTA had the most significant affect on both the mechanical properties and the adhesive behavior of dentine. Citric acid did not affect dentine wettability, whereas the indentation properties and the mineralization were reduced. Similar effects were observed when ozone was used. The dentinal tubules were significantly widened in citric acid compared to the ozone group. EDTA causes considerable micromechanical surface alteration of dentine and gutta-percha, but represents the best option in clinical cases where a high adhesiveness of the filling materials is desired.

  1. Significance of stacking fault energy on microstructural evolution in Cu and Cu-Al alloys processed by high-pressure torsion

    Science.gov (United States)

    An, X. H.; Lin, Q. Y.; Wu, S. D.; Zhang, Z. F.; Figueiredo, R. B.; Gao, N.; Langdon, T. G.

    2011-09-01

    Disks of pure Cu and several Cu-Al alloys were processed by high-pressure torsion (HPT) at room temperature through different numbers of turns to systematically investigate the influence of the stacking fault energy (SFE) on the evolution of microstructural homogeneity. The results show there is initially an inhomogeneous microhardness distribution but this inhomogneity decreases with increasing numbers of turns and the saturation microhardness increases with increasing Al concentration. Uniform microstructures are more readily achieved in materials with high or low SFE than in materials with medium SFE, because there are different mechanisms governing the microstructural evolution. Specifically, recovery processes are dominant in high or medium SFE materials, whereas twin fragmentation is dominant in materials having low SFE. The limiting minimum grain size (d min) of metals processed by HPT decreases with decreasing SFE and there is additional evidence suggesting that the dependence of d min on the SFE decreases when the severity of the external loading conditions is increased.

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

    International Nuclear Information System (INIS)

    Zhang, Z.B.; Mishin, O.V.; Tao, N.R.; Pantleon, W.

    2015-01-01

    The microstructure, hardness and tensile properties of a modified 9Cr−1Mo steel processed by dynamic plastic deformation (DPD) to different strains (0.5 and 2.3) have been investigated in the as-deformed and annealed conditions. It is found that significant structural refinement and a high level of strength can be achieved by DPD to a strain of 2.3, and that the microstructure at this strain contains a large fraction of high angle boundaries. The ductility of the DPD processed steel is however low. Considerable structural coarsening of the deformed microstructure without pronounced recrystallization takes place during annealing of the low-strain and high-strain samples for 1 h at 650 °C and 600 °C, respectively. Both coarsening and partial recrystallization occur in the high-strain sample during annealing at 650 °C for 1 h. For this sample, it is found that whereas coarsening alone results in a loss of strength with only a small gain in ductility, coarsening combined with pronounced partial recrystallization enables a combination of appreciably increased ductility and comparatively high strength

  3. Study on the microstructure of the different parts for new aluminum alloy forgings

    International Nuclear Information System (INIS)

    Gao Wei; Zheng Xiaojing; Wu Fu

    2014-01-01

    The mechanical properties of former aluminium alloy forgings cannot achieve technique demand. Because the component, dimension and preparation technology of new aluminum alloy have changed, the microstructure and mechanical properties of forgings are researched. It is concluded that the flowline of forgings has good continuity and uniformity, it does not have a prominent difference on microhardness of different parts. The results prove that the microstructure of forgings has good consistency. The matrix structure of forgings consists of fiber texture and equiaxed structure. The residual second phases, which are harmful to mechanical properties, are observed in the equiaxed structure. The center of equiaxed structure core zone, the edge of equiaxed structure transition zone and equiaxed structure edge zone should be focus on observing test, they are the sampling location of tensile property. (authors)

  4. Solidification microstructures in a short fiber reinforced alloy composite containing different fiber fractions

    Directory of Open Access Journals (Sweden)

    JING Qing-xiu

    2006-02-01

    Full Text Available The solidification microstructures and micro-segregation of a fiber reinforced Al-9 Cu alloy, containing different volume fractions of Al2O3 short fibers about 6 μm diameter and made by squeeze casting have been studied. The results indicate that as volume fraction of fiber Vf increases, the size of final grains becomes finer in the matrix. If λf /λ>1, the fibers have almost no influence on the solidification behavior of the matrix, so the final grains grow coarse, where λf is the average inter-fiber spacing and λ is the secondary dendrite arm spacing. While if λf /λ<1, the growth of crystals in the matrix is affected significantly by the fibers and the grain size is reduced to the value of the inter-fiber spacing. The fibers influence the average length of a solidification volume element L of the matrix and also influence the solidification time θt of the matrix. As a result of fibers influencing L and θt, the micro-segregation in the matrix is improved when the composite contains more fibers, although the level of the improvement is slight. The Clyne-Kurz model can be used to semi-quantitatively analyze the relationship between Vf and the volume fraction fe of the micro-segregation eutectic structure.

  5. Correlation Between the Microstructural Defects and Residual Stress in a Single Crystal Nickel-Based Superalloy During Different Creep Stages

    Science.gov (United States)

    Mo, Fangjie; Wu, Erdong; Zhang, Changsheng; Wang, Hong; Zhong, Zhengye; Zhang, Jian; Chen, Bo; Hofmann, Michael; Gan, Weimin; Sun, Guangai

    2018-03-01

    The present work attempts to reveal the correlation between the microstructural defects and residual stress in the single crystal nickel-based superalloy, both of which play the significant role on properties and performance. Neutron diffraction was employed to investigate the microstructural defects and residual stresses in a single crystal (SC) nickel-based superalloy, which was subjected to creeping under 220 MPa and 1000 °C for different times. The measured superlattice and fundamental lattice reflections confirm that the mismatch and tetragonal distortions with c/a > 1 exist in the SC superalloy. At the initially unstrained state, there exists the angular distortion between γ and γ' phases with small triaxial compressive stresses, ensuring the structural stability of the superalloy. After creeping, the tetragonal distortion for the γ phase is larger than that for the γ' phase. With increasing the creeping time, the mismatch between γ and γ' phases increases to the maximum, then decreases gradually and finally remains unchanged. The macroscopic residual stress shows a similar behavior with the mismatch, indicating the correlation between them. Based on the model of shear and dislocations, the evolution of microstructural defects and residual stress are reasonably explained. The effect of shear is dominant at the primary creep stage, which greatly enlarges the mismatch and the residual stress. The dislocations weaken the effect of shear for the further creep stage, resulting in the decrease of the mismatch and relaxation of the residual stress. Those findings add some helpful understanding into the microstructure-performance relationship in the SC nickel-based superalloy, which might provide the insight to materials design and applications.

  6. Cell behavior related to implant surfaces with different microstructure and chemical composition: an in vitro analysis.

    Science.gov (United States)

    Conserva, Enrico; Lanuti, Anna; Menini, Maria

    2010-01-01

    This paper reports on an in vitro comparison of osteoblast and mesenchymal stem cell (MSC) adhesion, proliferation, and differentiation related to two different surface treatments applied to the same implant design to determine whether the interaction between cells and implants is influenced by surface structure and chemical composition of the implants. Thirty-nine implants with a sandblasted (SB) surface and 39 implants with a grit-blasted and high-temperature acid-etched (GBAE) surface were used. The implant macrostructures and microstructures were analyzed by high- and low-voltage scanning electron microscopy (SEM) and by stereo-SEM. The surface chemical composition was investigated by energy dispersive analysis and x-ray photoemission spectroscopy. SaOS-2 osteoblasts and human MSCs were used for the evaluation of cell proliferation and alkaline phosphatase enzymatic activity in contact with the two surfaces. The GBAE surface showed fewer contaminants and a very high percentage of titanium (19.7%) compared to the SB surface (14.2%). The two surfaces showed similar mean roughness (Ra), but the depth (Rz) and density (RSm) of the porosity were significantly increased in the GBAE surface. The GBAE surface presented more osteoblast and MSC proliferation than the SB surface. No statistically significant differences in alkaline phosphatase activity were found between surfaces for either cellular line. The GBAE surface showed less surface contaminants and a higher percentage of titanium (19.7%) than the SB surface. The macro/micropore structured design and chemical composition of the GBAE surface allowed greater cell adhesion and proliferation and an earlier cell spreading but did not play an obvious role in in vitro cellular differentiation.

  7. Disease-Related Microstructural Differences in the Brain in Women With Provoked Vestibulodynia.

    Science.gov (United States)

    Gupta, Arpana; Woodworth, Davis C; Ellingson, Benjamin M; Rapkin, Andrea J; Naliboff, Bruce; Kilpatrick, Lisa A; Stains, Jean; Masghati, Salome; Tillisch, Kirsten; Mayer, Emeran A; Labus, Jennifer S

    2018-05-01

    Provoked vestibulodynia (PVD) is a chronic pelvic pain disorder affecting 16% of the female population. Neuroimaging studies have highlighted central abnormalities in PVD, similar to other chronic pelvic pain disorders, including brain regions involved in sensory processing and modulation of pain. The aim of the study was to determine alterations in the subvoxel, microstructural organization within tissues in PVD compared with healthy control participants (HCs) and a disease control group (irritable bowel syndrome [IBS]). Diffusion tensor imaging magnetic resonance imaging was conducted in 87 age-matched premenopausal women (29 PVD, 29 HCs, 29 IBS). Statistical parameter mapping of fractional anisotropy (FA) and mean diffusivity (MD) maps were used to identify microstructural difference in the brain specific to PVD or shared with IBS. PVD alterations in microstructural organization of the brain were predominantly observed in fibers associated with sensorimotor integration and pain processing that relay information between the thalamus, basal ganglia, sensorimotor, and insular cortex. PVD, compared with HCs, showed extensive increases in the FA of somatosensory and basal ganglia regions. In contrast, PVD and IBS subjects did not show any FA-related group differences. PVD subjects showed greater MD in the basal ganglia compared with HCs (higher MD in the internal capsule and pallidum) and IBS (higher MD in the putamen and pallidum). Increases in MD were associated with increased vaginal muscle tenderness and vulvar pain. The current findings highlight possible shared mechanisms between 2 different pelvic pain disorders, but also highlight the widespread alterations observed specifically in PVD compared with HCs. Alterations in microstructure in PVD were observed in fibers associated with sensorimotor integration and pain processing, which were also associated with increased vaginal muscle tenderness and vulvar pain. These alterations may be contributing to increased

  8. Parent socialization effects in different cultures: significance of directive parenting.

    Science.gov (United States)

    Sorkhabi, Nadia

    2012-06-01

    In this article, the controversy of divergent findings in research on parental socialization effects in different cultures is addressed. Three explanations intended to address divergent findings of socialization effects in different cultures, as advanced by researchers who emphasize cultural differences, are discussed. These include cultural differences in socialization values and goals of parents, parental emotional and cognitive characteristics associated with parenting styles, and adolescents' interpretations or evaluations of their parents' parenting styles. The empirical evidence for and against each of these arguments is examined and an alternative paradigm for understanding and empirical study of developmental outcomes associated with parenting styles in different cultures is suggested. Baumrind's directive parenting style is presented as an alternative to the authoritarian parenting style in understanding the positive developmental effects associated with "strict" parenting in cultures said to have a collectivist orientation. Directions for research on the three explanations are mentioned.

  9. Microstructure and texture evolution of different high manganese cast steels during hot deformation and subsequent treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lima, M.N.S.; Andrade, C.D.; Abreu, H.F.G. de; Klug, J.; Masoumi, M., E-mail: mohammad@alu.ufc.br [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Depto. de Engenharia Metalurgica e de Materiais; Ferreira, W.M. [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Curso de Engenharia Mecanica

    2016-07-01

    Microstructure and texture evolution were studied in two different austenitic high manganese cast steels in each processing condition. Special attention was paid to the effects of hot deformation and subsequent treatment on grain orientation behavior. The roles of Mn and C elements as well as heat treatment processes were investigated by Thermo-Calc. The texture evolutions in the as-cast, solution heat treatment, as-rolled and subsequent treatment were explored via orientation distribution function. The results showed that face-centred cube austenite was developed in steels. Strong {110}<115> texture component was characterized in as-cast in both alloys. Then, the inhomogeneity microstructure and the pronounced microsegregations were removed by annealing and Brass {110}<112>, {110}<111> and {221}<102> components were formed. Finally, cube {001}<100> component was developed during hot rolling in samples. (author)

  10. Microstructure and texture evolution of different high manganese cast steels during hot deformation and subsequent treatment

    International Nuclear Information System (INIS)

    Lima, M.N.S.; Andrade, C.D.; Abreu, H.F.G. de; Klug, J.; Masoumi, M.; Ferreira, W.M.

    2016-01-01

    Microstructure and texture evolution were studied in two different austenitic high manganese cast steels in each processing condition. Special attention was paid to the effects of hot deformation and subsequent treatment on grain orientation behavior. The roles of Mn and C elements as well as heat treatment processes were investigated by Thermo-Calc. The texture evolutions in the as-cast, solution heat treatment, as-rolled and subsequent treatment were explored via orientation distribution function. The results showed that face-centred cube austenite was developed in steels. Strong {110}<115> texture component was characterized in as-cast in both alloys. Then, the inhomogeneity microstructure and the pronounced microsegregations were removed by annealing and Brass {110}<112>, {110}<111> and {221}<102> components were formed. Finally, cube {001}<100> component was developed during hot rolling in samples. (author)

  11. Microstructural changes and strain hardening effects in abrasive contacts at different relative velocities and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Rojacz, H., E-mail: rojacz@ac2t.at [AC2T research GmbH, Viktor-Kaplan-Straße 2C, 2700 Wiener Neustadt (Austria); Mozdzen, G. [Aerospace & Advanced Composites GmbH, Viktor-Kaplan-Straße 2F, 2700 Wiener Neustadt (Austria); Weigel, F.; Varga, M. [AC2T research GmbH, Viktor-Kaplan-Straße 2C, 2700 Wiener Neustadt (Austria)

    2016-08-15

    Strain hardening is commonly used to reach the full potential of materials and can be beneficial in tribological contacts. 2-body abrasive wear was simulated in a scratch test, aimed at strain hardening effects in various steels. Different working conditions were examined at various temperatures and velocities. Strain hardening effects and microstructural changes were analysed with high resolution scanning electron microscopy (HRSEM), electron backscatter diffraction (EBSD), micro hardness measurements and nanoindentation. Statistical analysing was performed quantifying the influence of different parameters on microstructures. Results show a crucial influence of temperature and velocity on the strain hardening in tribological contacts. Increased velocity leads to higher deformed microstructures and higher increased surface hardness at a lower depth of the deformed zones at all materials investigated. An optimised surface hardness can be achieved knowing the influence of velocity (strain rate) and temperature for a “tailor-made” surface hardening in tribological systems aimed at increased wear resistance. - Highlights: •Hardening mechanisms and their intensity in tribological contacts are dependent on relative velocity and temperature. •Beneficial surface hardened zones are formed at certain running-in conditions; the scientific background is presented here. •Ferritic-pearlitic steels strain hardens via grain size reduction and decreasing interlamellar distances in pearlite. •Austenitic steels show excellent surface hardening (120% hardness increase) by twinning and martensitic transformation. •Ferritic steels with hard phases harden in the ferrite phase as per Hall-Petch equation and degree of deformation.

  12. Microstructural changes and strain hardening effects in abrasive contacts at different relative velocities and temperatures

    International Nuclear Information System (INIS)

    Rojacz, H.; Mozdzen, G.; Weigel, F.; Varga, M.

    2016-01-01

    Strain hardening is commonly used to reach the full potential of materials and can be beneficial in tribological contacts. 2-body abrasive wear was simulated in a scratch test, aimed at strain hardening effects in various steels. Different working conditions were examined at various temperatures and velocities. Strain hardening effects and microstructural changes were analysed with high resolution scanning electron microscopy (HRSEM), electron backscatter diffraction (EBSD), micro hardness measurements and nanoindentation. Statistical analysing was performed quantifying the influence of different parameters on microstructures. Results show a crucial influence of temperature and velocity on the strain hardening in tribological contacts. Increased velocity leads to higher deformed microstructures and higher increased surface hardness at a lower depth of the deformed zones at all materials investigated. An optimised surface hardness can be achieved knowing the influence of velocity (strain rate) and temperature for a “tailor-made” surface hardening in tribological systems aimed at increased wear resistance. - Highlights: •Hardening mechanisms and their intensity in tribological contacts are dependent on relative velocity and temperature. •Beneficial surface hardened zones are formed at certain running-in conditions; the scientific background is presented here. •Ferritic-pearlitic steels strain hardens via grain size reduction and decreasing interlamellar distances in pearlite. •Austenitic steels show excellent surface hardening (120% hardness increase) by twinning and martensitic transformation. •Ferritic steels with hard phases harden in the ferrite phase as per Hall-Petch equation and degree of deformation.

  13. Prognostic significance of between-arm blood pressure differences.

    Science.gov (United States)

    Agarwal, Rajiv; Bunaye, Zerihun; Bekele, Dagim M

    2008-03-01

    Blood pressure (BP) recordings often differ between arms, but the extent to which these differences are reproducible and whether the differences have prognostic importance is unknown. We enrolled 421 consecutive patients from a medicine and a renal clinic at a veterans' hospital. Three BP recordings were obtained in each arm using an oscillometric device in a sequential manner and repeated in 1 week. Patients were followed for all-cause mortality arm had 5.1-mm Hg higher systolic BP that attenuated by approximately 2.2 mm Hg a week later. Systolic BP dropped 6.9 mm Hg over 1 week and by an additional 5.3 mm Hg in patients with chronic kidney disease. Accounting for the visit and arm effect improved the reproducibility of the BP measurements. The intraclass correlation coefficient was 0.74, which improved to 0.88 after accounting for visit and 0.93 after accounting for arm. The crude mortality rate was 6.33 per 100 patient-years. Every 10-mm Hg difference in systolic BP between the arms conferred a mortality hazard of 1.24 (95% CI: 1.01 to 1.52) after adjusting for average systolic BP and chronic kidney disease. BP differences between arms are reproducible and carry prognostic information. Patients should have evaluation of BP in both arms at the screening visit.

  14. Conducting tests for statistically significant differences using forest inventory data

    Science.gov (United States)

    James A. Westfall; Scott A. Pugh; John W. Coulston

    2013-01-01

    Many forest inventory and monitoring programs are based on a sample of ground plots from which estimates of forest resources are derived. In addition to evaluating metrics such as number of trees or amount of cubic wood volume, it is often desirable to make comparisons between resource attributes. To properly conduct statistical tests for differences, it is imperative...

  15. Significance of perfectionism in understanding different forms of insomnia

    OpenAIRE

    Totić-Poznanović Sanja; Šaula-Marojević Biljana; Zebić Mirjana

    2012-01-01

    Introduction. Studies consistently show a connection between perfectionism as a multidimensional construct with various psychological and psychopathological states and characteristics. However, studies that analyze the connection between this concept and sleep disturbances, especially modalities of insomnia, are rare. Objective. The aim of this study was to examine whether dimensions of perfectionism can explain different forms of insomnia; difficulties initiating sleep (insomnia early)...

  16. Significant Differences in Nurses’ Knowledge of Basic Wound Management

    DEFF Research Database (Denmark)

    Zarchi, Kian; Latif, Seemab; Haugaard, Vibeke B

    2014-01-01

    Wounds represent a growing healthcare problem due to an aging population. Nurses play a key role in wound management and their theoretical understanding of basic wound management may be expected to influence the quality of wound therapy fundamentally. In this study, we evaluated the level...... of knowledge of wound management in 136 Danish nurses working in 3 different settings: advanced wound care clinics, home care and general hospital departments. We found that hospital nurses had less theoretical knowledge than home care nurses and nurses working at advanced wound care clinics. We also found...... of wound management in Denmark and suggests how improvements might be achieved....

  17. Microstructure, optical characterization and light induced degradation in a-Si:H deposited at different temperatures

    International Nuclear Information System (INIS)

    Minani, E.; Sigcau, Z.; Adgebite, O.; Ramukosi, F.L.; Ntsoane, T.P.; Harindintwari, S.; Knoesen, D.; Comrie, C.M.; Britton, D.T.; Haerting, M.

    2006-01-01

    The microstructure and optical properties of a series of hydrogenated amorphous silicon layers deposited on glass substrates at different temperature have been characterized by means of X-ray diffraction techniques and optical spectroscopy. The radial distribution function of the as-deposited samples showed an increase in the bond angle and a decrease in the radial distance indicating a relaxation of the amorphous network with increasing the deposition temperature. Light induced degradation was studied using a simulated daylight spectrum. The changes in hydrogen bonding configuration, associated with the light soaking at different stages of illumination, was monitored via the transmission bands of the vibrational wag and stretch modes of the IR spectrum

  18. Microstructure-based constitutive modeling of TRIP steel: Prediction of ductility and failure modes under different loading conditions

    International Nuclear Information System (INIS)

    Choi, K.S.; Liu, W.N.; Sun, X.; Khaleel, M.A.

    2009-01-01

    We study the ultimate ductility and failure modes of a commercial transformation-induced plasticity (TRIP) 800 steel under different loading conditions with an advanced microstructure-based finite-element analysis. The representative volume element (RVE) for the TRIP 800 under examination is developed based on an actual microstructure obtained from scanning electron microscopy. The ductile failure of the TRIP 800 under different loading conditions is predicted in the form of plastic strain localization without any prescribed failure criteria for the individual phases. This indicates that the microstructure-level inhomogeneity of the various constituent phases can be the key factor influencing the final ductility of the TRIP 800 steel under different loading conditions. Comparisons of the computational results with experimental measurements suggest that the microstructure-based modeling approach accurately captures the overall macroscopic behavior of the TRIP 800 steel under different loading and boundary conditions.

  19. Microstructure, mechanical behaviour and fracture of pure tungsten wire after different heat treatments

    DEFF Research Database (Denmark)

    Zhao, P.; Riesch, J.; Höschen, T.

    2017-01-01

    Plastic deformation of tungsten wire is an effective source of toughening tungsten fibre-reinforced tungsten composites (Wf/W) and other tungsten fibre-reinforced composites. To provide a reference for optimization of those composites, unconstrained pure tungsten wire is studied after various hea...... a rather different microstructure. As-fabricated wire and wire recrystallized at 1273 K for 3 h show fine grains with a high aspect ratio and a substantial plastic deformability: a clearly defined tensile strength, high plastic work, similar necking shape, and the characteristic knife...

  20. Microstructure and Mechanical Behavior of Deep Drawing DC04 Steel at Different Length Scales

    OpenAIRE

    Schreijäg, Simone

    2013-01-01

    The deformation behavior of steels is strongly influenced by their microstructure which is a result of the alloying elements and thermal treatments. In this work, the microstructure and the deformation behavior of a non-alloyed deep drawing DC04 steel was investigated. The microstructure was analyzed during heat treatment by EBSD, then microcompression experiments were performed on selected microstructural units and then bulk steel samples were mechanically tested by tensile experiments.

  1. Differences in the microstructure and rheological properties of low-fat yoghurts from goat, sheep and cow milk.

    Science.gov (United States)

    Nguyen, Hanh T H; Afsar, Saeedeh; Day, Li

    2018-06-01

    Goat and sheep milks have long been used to produce a range of dairy products due to their nutritional value and health benefits. Information about the microstructure and rheology of goat and sheep yoghurts, however, is scarce. In this study, the microstructure, texture and rheological properties of cow, goat and sheep yoghurts were investigated and compared. The results show that a longer fermentation and gelation time was required for goat yoghurt with a lower storage modulus compared to cow and sheep yoghurts. Cooling resulted in an increase in the storage modulus at different magnitudes for cow, goat and sheep yoghurts. Goat yoghurt had a smaller particle size and a softer gel, which is linked with a more porous microstructure. The results obtained here demonstrate the effect of different milk types on the properties of yoghurts and provide a better understanding into the link between the microstructure and physical properties of the product. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Zirconium microstructures: uncharted possibilities

    International Nuclear Information System (INIS)

    Samajdar, I.; Kumar, Gulshan; Singh, Jaiveer; Lodh, Arijit; Srivastava, D.; Tewari, R.; Dey, G.K.; Saibaba, N.

    2015-01-01

    The 'conventional' Zirconium microstructures can be significantly extended with information on: (i) microtexture, (ii) residual stresses and (iii) local mechanical properties. Though these involve different tools, but a consolidated microstructure can be crated. This is the theme of this presentation. Examples of this consolidated picture will be made from deformation twinning, recovery-recrystallization, burst ductility and orientation versus solid solution hardening. (author)

  3. Population differences in brain morphology and microstructure among Chinese, Malay, and Indian neonates.

    Science.gov (United States)

    Bai, Jordan; Abdul-Rahman, Muhammad Farid; Rifkin-Graboi, Anne; Chong, Yap-Seng; Kwek, Kenneth; Saw, Seang-Mei; Godfrey, Keith M; Gluckman, Peter D; Fortier, Marielle V; Meaney, Michael J; Qiu, Anqi

    2012-01-01

    We studied a sample of 75 Chinese, 73 Malay, and 29 Indian healthy neonates taking part in a cohort study to examine potential differences in neonatal brain morphology and white matter microstructure as a function of ethnicity using both structural T2-weighted magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). We first examined the differences in global size and morphology of the brain among the three groups. We then constructed the T2-weighted MRI and DTI atlases and employed voxel-based analysis to investigate ethnic differences in morphological shape of the brain from the T2-weighted MRI, and white matter microstructure measured by fractional anisotropy derived from DTI. Compared with Malay neonates, the brains of Indian neonates' tended to be more elongated in anterior and posterior axis relative to the superior-inferior axis of the brain even though the total brain volume was similar among the three groups. Although most anatomical regions of the brain were similar among Chinese, Malay, and Indian neonates, there were anatomical variations in the spinal-cerebellar and cortical-striatal-thalamic neural circuits among the three populations. The population-related brain regions highlighted in our study are key anatomical substrates associated with sensorimotor functions.

  4. Structure, microstructure and magnetic properties of electrodeposited Co and Co-Pt in different nanoscale geometries

    Energy Technology Data Exchange (ETDEWEB)

    Khatri, Manvendra Singh

    2010-07-09

    Thin films and nanowires of Co-Pt have been prepared by means of electrodeposition. Composition, structure, microstructure and magnetic properties have been intensively studied using X-ray diffraction, scanning electron microscopy and vibrating sample magnetometry and correlated to the deposition parameters such as electrolyte composition, deposition current and/or potential. Co rich Co-Pt films have been deposited at various current densities. A nearly constant composition of Co{sub 70}Pt{sub 30} was achieved for current densities between 18 and 32 mA/cm{sup 2}. Detailed texture measurements confirmed an increasing fraction of the hexagonal phase with its c-axis aligned perpendicular to the film plane with increasing current density. Accordingly, magnetic properties are strongly affected by the magnetocrystalline anisotropy of the hexagonal phase that competes with the shape anisotropy of the thin film geometry. Co-Pt nanowires have been prepared within alumina templates at different deposition potentials between -0.6 and -0.9 V{sub SCE} changing the composition from nearly pure Pt to Co. The composition Co{sub 80}Pt{sub 20} was observed at a deposition potential of -0.7 V{sub SCE}. Co-Pt nanowires are nanocrystalline in the as-deposited state. Magnetic measurements reveal changing fcc and hcp phase fractions within the wires as the effective anisotropy significantly differs from the expected shape anisotropy for nanowires with high aspect ratio. This change in effective anisotropy is attributed to the preferential alignment of the c-axis of hcp Co-Pt phase perpendicular to the nanowires axis. A promising alternative with much smaller feature sizes is the diblock copolymer template. Electrodeposition of Co and Co-Pt into these templates has been carried out. Inhomogeneities in the template thickness as well as a certain substrate roughness have been identified to be the reasons for inhomogeneous template filling. Thus magnetic properties are dominated by large

  5. Microstructure and properties of TiC-high manganese steel cermet prepared by different sintering processes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhi; Lin, Tao, E-mail: lintao@ustb.edu.cn; He, Xinbo; Shao, Huiping; Zheng, Jianshu; Qu, Xuanhui

    2015-11-25

    In the paper, the TiC −50 wt.% high manganese steel cermet was made with different sintering processes including vacuum sintering, hot pressing, microwave sintering and spark plasma sintering (SPS). The microstructure, porosity and fracture morphology of the samples were analyzed with scanning electron microscopy (SEM). Phase analysis was carried out using X-ray diffraction (XRD). The density, hardness, transverse rupture strength (TRS) and wear resistance were investigated for the effect of the sintering processes. The results showed that the core–shell structure was not clearly observed for the TiC particles in microstructures and the high manganese steel matrix is BCC structure. Hot pressing, microwave sintering and SPS are useful processes for densification of the cermet. Nearly full density and higher hardness can be reached by these three processes at a lower sintering temperature and in a shorter sintering time. However, higher TRS can be reached by means of alloying completely in a longer sintering time, for example vacuum sintering. Pre-sintering in a long sintering time at a lower sintering temperature is also useful for improving the TRS. Finally, vacuum sintering is an effective process for producing this composite with the lowest cost in the mass production. - Highlights: • TiC-high manganese steel cermets were prepared by four sintering processes. • The core–shell structure was not clearly observed for the TiC particles in microstructures. • Th high manganese steel matrix is BCC structure instead of FCC structure. • Pre-sintering before microwave sintering is also useful for improving the TRS. • Vacuum sintering can be effective way for prepare this cermet in mass production.

  6. Analysis of the microstructure of Xenodontinae snake scales associated with different habitat occupation strategies

    Directory of Open Access Journals (Sweden)

    O. Rocha-Barbosa

    Full Text Available The morphology of many organisms seems to be related to the environment they live in. Nonetheless, many snakes are so similar in their morphological patterns that it becomes quite difficult to distinguish any adaptive divergence that may exist. Many authors suggest that the microornamentations on the scales of reptiles have important functional value. Here, we examined variations on the micromorphology of the exposed oberhautchen surface of dorsal, lateral, and ventral scales from the mid-body region of Xenodontinae snakes: Sibynomorphus mikani (terricolous, Imantodes cenchoa (arboreal, Helicops modestus (aquatic and Atractus pantostictus (fossorial. They were metallized and analyzed through scanning electron microscopy. All species displayed similar microstructures, such as small pits and spinules, which are often directed to the scale caudal region. On the other hand, there were some singular differences in scale shape and in the microstructural pattern of each species. S. mikani and I. cenchoa have larger spinules arranged in a row which overlap the following layers on the scale surface. Species with large serrate borders are expected to have more frictional resistance from the caudal-cranial direction. This can favor life in environments which require more friction, facilitating locomotion. In H. modestus, the spinules are smaller and farther away from the posterior rows, which should help reduce water resistance during swimming. The shallower small pits found in this species can retain impermeable substances, as in aquatic Colubridae snakes. The spinules adhering to the caudal scales of A. pantostictus seem to form a more regular surface, which probably aid their fossorial locomotion, reducing scale-ground friction. Our data appear to support the importance of functional microstructure, contributing to the idea of snake species adaptation to their preferential microhabitats.

  7. Quantifying sex, race, and age specific differences in bone microstructure requires measurement of anatomically equivalent regions.

    Science.gov (United States)

    Ghasem-Zadeh, Ali; Burghardt, Andrew; Wang, Xiao-Fang; Iuliano, Sandra; Bonaretti, Serena; Bui, Minh; Zebaze, Roger; Seeman, Ego

    2017-08-01

    Individuals differ in forearm length. As microstructure differs along the radius, we hypothesized that errors may occur when sexual and racial dimorphisms are quantified at a fixed distance from the radio-carpal joint. Microstructure was quantified ex vivo in 18 cadaveric radii using high resolution peripheral quantitative computed tomography and in vivo in 158 Asian and Caucasian women and men at a fixed region of interest (ROI), a corrected ROI positioned at 4.5-6% of forearm length and using the fixed ROI adjusted for cross sectional area (CSA), forearm length or height. Secular effects of age were assessed by comparing 38 younger and 33 older women. Ex vivo, similar amounts of bone mass fashioned adjacent cross sections. Larger distal cross sections had thinner porous cortices of lower matrix mineral density (MMD), a larger medullary CSA and higher trabecular density. Smaller proximal cross-sections had thicker less porous cortices of higher MMD, a small medullary canal with little trabecular bone. Taller persons had more distally positioned fixed ROIs which moved proximally when corrected. Shorter persons had more proximally positioned fixed ROIs which moved distally when corrected, so dimorphisms lessened. In the corrected ROIs, in Caucasians, women had 0.6 SD higher porosity and 0.6 SD lower trabecular density than men (pmicrostructure requires measurement of anatomically equivalent regions. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Break Differed Induced by Hydrides (BDIH) in Zr-2,5Nb: Microstructure effect

    International Nuclear Information System (INIS)

    Mieza, J. Ignacio; Domizzi, Gladys; Vigna, Gustavo L

    2006-01-01

    The alloys of Zr-2,5%Nb are susceptible to be degraded for the incorporation of hydrogen in their matrix. One of the mechanisms of the damage by hydrogen known as Break Differed Induced by Hydrides (BDIH) consists of the evolution, in discreet steps, of a crack inside the matrix by the fragile break of the hydride phase. The parameter utilized to characterize the severity of the process of BDIH is the velocity of advance of the crack. The variables that affect to the velocity are the solicitations of external load, the thermal cycles, the content of hydrogen and the microstructure of the material. The Zr-2, 5% Nb of nuclear use is a two-phase alloy (α-β) constituted by the phase alpha (rich in Zr) and β-Zr (rich in Nb) retained since high temperature. In service, the phase metastable evolves toward the stable phase depending on the time and the temperature of operation. In this work the effects of the evolution of the phase β-Zr on the velocity of BDIH are studied, measure with emission acoustics. The microstructural characterization was done by means of obtained dust X-rays diffraction by anodic dissolution of the material. The results obtained show the decrease of the velocity of propagation of the crack with the degree of advance of the transformation toward the phase β-Nb, consistent effect with the differences observed in the coefficients of diffusion of each phase (AG)

  9. Influence of microstructure of different stainless steels on their low cycle fatigue damage mechanisms

    International Nuclear Information System (INIS)

    Baffie, Natacha

    2002-01-01

    The present study is focused on understanding low cycle fatigue damage mechanisms in three different kind of stainless steels. In all structures, crack propagation is conditioned by microstructural barriers. In single phase austenitic alloys, short cracks initiation and growth are crystallographic. Cracks are arrested by grain and twin boundaries both at surface and in the bulk. Grain size refinement improve the fatigue life at applied Δε p . The second barrier in the bulk is shown to be very efficient because of the important number of misoriented grains. In the metastable austenitic alloy, the martensitic transformation induced by cyclic straining leads to significant modifications of damage mechanisms. The fatigue behaviour has been investigated between -50 deg. C and 120 deg. C. The γ→α' transformation takes place at the surface, in the bulk (except at 120 deg. C) and locally at the crack tip. At all temperatures, the amount of martensite formed and the fatigue life increase as the grain size decreases, even if at the same Δε p , the maximal stresses are considerably higher than in a stable γ. Short cracks growth takes place in transformed regions, γ→α' transformation being assisted by strain concentrations at the crack tip. This mechanism consumes a part of plastic deformation, which would have been available for crack propagation. Such a dynamic barrier can decrease crack propagation rate. The austenite grain size is shown to have a decisive influence both on the amount of martensite formed and on the fatigue resistance through the effect of γ grain boundaries as indirect barriers to the crack propagation. The fatigue life of the 475 deg. C aged α/γ alloy decreases sharply at high applied Δε p compared to the solution annealed one. This behaviour is explained by the modification of short cracks nucleation sites. Indeed, cleavage occurs in the hard and brittle α phase, even if plastic deformation is concentrated in γ phase. Then, easy

  10. Age-related changes in vertebral and iliac crest 3D bone microstructure--differences and similarities.

    Science.gov (United States)

    Thomsen, J S; Jensen, M V; Niklassen, A S; Ebbesen, E N; Brüel, A

    2015-01-01

    Age-related changes of vertebra and iliac crest 3D microstructure were investigated, and we showed that they were in general similar. The 95th percentile of vertebral trabecular thickness distribution increased with age for women. Surprisingly, vertebral and iliac crest bone microstructure was only weakly correlated (r = 0.38 to 0.75), despite the overall similar age-related changes. The purposes of the study were to determine the age-related changes in iliac and vertebral bone microstructure for women and men over a large age range and to investigate the relationship between the bone microstructure at these skeletal sites. Matched sets of transiliac crest bone biopsies and lumbar vertebral body (L2) specimens from 41 women (19-96 years) and 39 men (23-95 years) were micro-computed tomography (μCT) scanned, and the 3D microstructure was quantified. For both women and men, bone volume per total volume (BV/TV), connectivity density (CD), and trabecular number (Tb.N) decreased significantly, while structure model index (SMI) and trabecular separation (Tb.Sp) increased significantly with age at either skeletal site. Vertebral trabecular thickness (Tb.Th) was independent of age for both women and men, while iliac Tb.Th decreased significantly with age for men, but not for women. In general, the vertebral and iliac age-related changes were similar. The 95th percentile of the Tb.Th distribution increased significantly with age for women but was independent of age for men at the vertebral body, while it was independent of age for either sex at the iliac crest. The Tb.Th probability density functions at the two skeletal sites became significantly more similar with age for women, but not for men. The microstructural parameters at the iliac crest and the vertebral bodies were only moderately correlated from r = 0.38 for SMI in women to r = 0.75 for Tb.Sp in men. Age-related changes in vertebral and iliac bone microstructure were in general similar. The iliac

  11. Different histopathological subtypes of Hodgkin lymphoma show significantly different levels of FDG uptake

    DEFF Research Database (Denmark)

    Hutchings, Martin; Loft, Annika; Hansen, Mads

    2006-01-01

    ) patients, 20.8 g/ml in 11 mixed cellularity (MC) patients, and 19.5 g/ml in four patients with unclassified classical HL (CHL-NOS), (ANOVA, p = 0.011). Out of 780 sites (600 lymph node regions plus 180 organs), 208 sites were found to be affected with HL. Mean SUV(max) was 8.3 g/ml in the 12 sites with NLP......, 11.2 g/ml in the 147 sites affected with NS, 14.6 g/ml in the 36 sites with MC, and 13.1 g/ml in the 13 sites with CHL-NOS (ANOVA, p = 0.002). There is a significant difference in FDG/glucose uptake between the different histopathological subtypes of HL....

  12. DYNAMIC COMPUTER SIMULATION OF CONCRETE ON DIFFERENT LEVELS OF THE MICROSTRUCTURE – PART 2

    Directory of Open Access Journals (Sweden)

    Piet Stroeven

    2011-05-01

    Full Text Available The establishment of an experimental basis for the dependence of a mechanical property on certain structural features (and the associated micro-mechanical properties would require extensive, cumbersome and complicated testing: mechanical testing for defining the very property, quantitative (section image analysis and stereological three-dimensional assessment of the relevant structural features. 'Realistic' simulation of material structure by computer would therefore offer an interesting alternative. This paper introduces the SPACE system (Software Package for the Assessment of Compositional Evolution as the most recent development in this field. It has been developed to assess the composition as well as configuration characteristics of dense random packing situations in opaque materials. This paper presents an introduction to the system and will thereupon highlight by means of illustrative examples of typical applications on different levels of the microstructure the system's capabilities. Although only a single application can be presented in this framework, they all concern areas of major engineering interest.

  13. Effects of ion beam irradiation on the microstructures and strengths of different carbon fibers

    International Nuclear Information System (INIS)

    Oku, Tatsuo; Kurumada, Akira; Kawamata, Kiyohiro; Inagaki, Michio

    1998-01-01

    The high energy argon ion was irradiated to different carbon fibers with various microstructures. The cross-sectional structures and strengths properties have been evaluated before and after ion irradiation. As a result, the diameter of fibers decreased due to ion irradiation, except for the fiber with dual structure. The tensile strength also decreased due to ion irradiation, except for fibers which were not heat-treated. This suggests that it is necessary to consider not only the defects in the vertical cross-section but also changes in defect structures in the axial direction. The results of computer simulation indicated that argon ion with 175MeV/1μA produced homogeneous defects in the carbon fibers with the diameter of about 20 μm. (author)

  14. Microstructural Evolution of Advanced Radiation-Resistant ODS Steel with Different Lengths of Mechanical Alloying Time

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sanghoon; Kim, Ga Eon; Kang, Suk Hoon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling well occurred to 120dpa at high temperatures and this leads the decrease of the mechanical properties and dimensional stability. Compared to this, ferritic/ martensitic steel is a good solution because of excellent thermal conductivity and good swelling resistance. Unfortunately, the available temperature range of ferritic/martensitic steel is limited up to 650 .deg. C. ODS steel is the most promising structural material because of excellent creep and irradiation resistance by uniformly distributed nano-oxide particles with a high density which is extremely stable at the high temperature in ferritic/martensitic matrix. In this study, powder properties and microstructures of the ODS steel with different length of mechanical alloying time was investigated. The ODS steel milled 5h showed homogeneous grain structure with the highest hardness.

  15. Microstructural Evolution of Advanced Radiation-Resistant ODS Steel with Different Lengths of Mechanical Alloying Time

    International Nuclear Information System (INIS)

    Noh, Sanghoon; Kim, Ga Eon; Kang, Suk Hoon; Kim, Tae Kyu

    2015-01-01

    Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling well occurred to 120dpa at high temperatures and this leads the decrease of the mechanical properties and dimensional stability. Compared to this, ferritic/ martensitic steel is a good solution because of excellent thermal conductivity and good swelling resistance. Unfortunately, the available temperature range of ferritic/martensitic steel is limited up to 650 .deg. C. ODS steel is the most promising structural material because of excellent creep and irradiation resistance by uniformly distributed nano-oxide particles with a high density which is extremely stable at the high temperature in ferritic/martensitic matrix. In this study, powder properties and microstructures of the ODS steel with different length of mechanical alloying time was investigated. The ODS steel milled 5h showed homogeneous grain structure with the highest hardness

  16. Effect of Ion Beam Irradiation on Silicon Carbide with Different Microstructures

    International Nuclear Information System (INIS)

    Park, Kyeong Hwan; Park, Ji Yeon; Kim, Weon Ju; Jung, Choong Hwan; Ryu, Woo Seog

    2006-01-01

    SiC and SiC/SiC composites are one of promising candidates for structural materials of the next generation energy systems such as the gas-cooled reactors and fusion reactors. This anticipation yields many material issues, and radiation effects of silicon carbide are recognized as an important research subject. Silicon carbide has diverse crystal structures (called polytypes), such as α-SiC (hexagonal structure), β-SiC (cubic structure) and amorphous SiC. Among these polytypes, β-SiC has been studied as matrix material in SiC/SiC composites. Near-stoichiometric β-SiC with high crystallinity and purity is considered as suitable material in the next generation energy system and matrix material in SiC/SiC composites because of its excellent radiation resistance. Highly pure and crystalline β-SiC and SiC/SiC composites could be obtained by the chemical vapor deposition (CVD) and Infiltration (CVI) process using a gas mixture of methyltrichlorosilane (CH 3 SiCl 3 , MTS) and purified H 2 . SiC produced by the CVD method has different grain size and microstructural morphology depended on the process conditions such as temperature, pressure and the input gas ratio. In this work, irradiation effects of silicon carbide were investigated using ion beam irradiation with emphasis on the influence of grain size and grain boundary. MeV ion irradiation at low temperature makes amorphous phase in silicon carbide. The microstructures and mechanical property changes of silicon carbide with different structures were analyzed after ion beam irradiation

  17. Production, microstructure and mechanical properties of two different austenitic ODS steels

    Energy Technology Data Exchange (ETDEWEB)

    Gräning, T., E-mail: tim.graening@kit.edu; Rieth, M.; Hoffmann, J.; Möslang, A.

    2017-04-15

    This article is to summarize and examine processing parameters of novel developed austenitic oxide dispersed strengthened (ODS) steels. Comparing hot-rolled and extruded conditions after the same degree of deformation after and before annealing, are just some examples to give insights into the complex processing of austenitic ODS steels. One of the major drawbacks of the material is the more sophisticated production process. Due to a ductile matrix material with an increased stickiness during milling, a two-step milling procedure with the use of ZrO{sub 2} milling balls was applied to raise the production yield and to use the abrasion of the ZrO{sub 2} as an additional element to facilitate the formation of nano-sized precipitates. To get a better understanding how the different powder particle sizes after milling affect final properties, sieving was applied and revealed a serious effect in terms of precipitate size, distribution and mechanical properties. Grain sizes in relation to the precipitate size, annealing time and processing parameters were determined and compared to the mechanical properties. Hardness and tensile test have pointed out, that the precipitate size and number are more important in respect to the ultimate tensile strength than the grain size and that in this study hot-rolled material exhibited the better properties. The investigation of the microstructure illustrated the stability of precipitates during annealing at 1100 °C for 40 h. These heat treatments also led to a consistent grain size, due to the pinning effect of the grain boundaries, caused by precipitates. - Highlights: •Comparison of the microstructure of extruded and hot-rolled ODS. •Two-step mechanical alloying with ZrO{sub 2} milling balls. •Determination of precipitate size distribution depending on chemical composition and annealing times. •Determination of the influence of sieving of mechanical alloyed powder on the near net shape products. •Tensile tests of two

  18. Magnetic properties and microstructure investigation of electrodeposited FeNi/ITO films with different thickness

    International Nuclear Information System (INIS)

    Cao, Derang; Wang, Zhenkun; Feng, Erxi; Wei, Jinwu; Wang, Jianbo; Liu, Qingfang

    2013-01-01

    Highlights: •FeNi alloy thin films with different thickness deposited on Indium Tin Oxides (ITOs) conductive glass substrates by electrodeposition method. •A columnar crystalline microstructure and domain structure were obtained in FeNi thin films. •Particular FMR spectra of FeNi alloy with different thickness were studied. -- Abstract: FeNi alloy thin films with different thickness deposited on Indium Tin Oxides (ITOs) conductive glass substrates from the electrolytes by electrodeposition method have been studied by magnetic force microscopy (MFM), scanning electron microscopy (SEM) and ferromagnetic resonance (FMR) technique. For these films possessing an in-plane isotropy, the remanence decreases with the increasing of film thickness and the critical thickness that a stripe domain structure emerges is about 116 nm. Characteristic differences of the FMR spectra of different thickness are also observed. The results show that the resonance field at high measured angle increases firstly then decreases with increasing thickness, which may be related to the striped domain structure

  19. Microstructural differences between two Zr(C,N) coatings revealed by analytical transmission electron microscopy

    International Nuclear Information System (INIS)

    Dörfel, Ilona; Rooch, Heidemarie; Österle, Werner

    2012-01-01

    The microstructures of two samples of a Zr(C,N) coating on steel, which unexpectedly differed in their tribological properties, were investigated by analytical transmission electron microscopy. The samples were produced by a cathodic arc evaporation process in two commercial coating devices under similar coating conditions with the exception of the number of Zr targets. The source of the differing tribological properties of the samples was detected by analytical transmission electron microscopy (TEM) methods energy-dispersive X-ray spectroscopy (EDX), energy filtering TEM (EFTEM), electron diffraction, high resolution electron microscopy, and high angel annular dark field. The TEM preparation and the results of the TEM investigations are shown in detail. The origin of the unexpected behavior was determined to be a nano-scale multilayer structure that existed only in the tribologically superior specimen. EDX and EFTEM investigations indicated enrichment in oxygen at the interface between coating and steel substrate in the tribologically inferior sample. Findings of the microstructural configuration were obtained by taking a closer look at the structure and comparing the results of the several analytical TEM techniques. This allows the allocation of the concentration fluctuations in N, C, and Zr to the two thickness fractions of the nano multilayers and a local correlation of the identified minority phase Zr 3 (C,N) 4 to the higher N content in the narrower type of the multilayer fraction of the sample with the excellent tribological properties. The minority phase Zr 3 (C,N) 4 is randomly distributed in the sample with the defective tribological properties. Coating conditions are not topic of this work, but after discussion of the TEM results, the fact that one of the coating devices worked with one Zr target and the other one with two, could be identified as cause for the formation of the nano multilayer structure in the sample with the superior tribological

  20. On the determining role of microstructure of niobium-microalloyed steels with differences in impact toughness

    International Nuclear Information System (INIS)

    Anumolu, R.; Kumar, B. Ravi; Misra, R.D.K.; Mannering, T.; Panda, D.; Jansto, S.G.

    2008-01-01

    The relationship between microstructure and impact toughness was investigated for niobium-microalloyed steels with similar yield strength. The nominal steel composition was similar and any variation in processing history was unintentional. The general microstructure of the investigated steel was similar and consisted of 85% polygonal ferrite and 15% pearlite. Despite these similarities, they exhibited variation in toughness and were classified as high- and low-toughness steels. Detailed microstructural investigation including stereological analysis and electron microscopy implied that toughness is strongly influenced by mean intercept length of polygonal ferrite and pearlite colony, and their distribution, interlamellar spacing, and degenerated pearlite

  1. On the determining role of microstructure of niobium-microalloyed steels with differences in impact toughness

    Energy Technology Data Exchange (ETDEWEB)

    Anumolu, R. [Center for Structural and Functional Materials, University of Louisiana at Lafayette, LA 70504-4130 (United States); Department of Chemical Engineering, University of Louisiana at Lafayette, Lafayette, LA 70504-4130 (United States); Kumar, B. Ravi [Center for Structural and Functional Materials, University of Louisiana at Lafayette, LA 70504-4130 (United States); Misra, R.D.K. [Center for Structural and Functional Materials, University of Louisiana at Lafayette, LA 70504-4130 (United States); Department of Chemical Engineering, University of Louisiana at Lafayette, Lafayette, LA 70504-4130 (United States)], E-mail: dmisra@louisiana.edu; Mannering, T.; Panda, D. [Nucor-Yamato Steel, P.O. Box 1228, 5929 East State Highway 18, Blytheville, AR 72316 (United States); Jansto, S.G. [Reference Metals, 1000 Old Pond Road, Bridgeville, PA 15017 (United States)

    2008-09-15

    The relationship between microstructure and impact toughness was investigated for niobium-microalloyed steels with similar yield strength. The nominal steel composition was similar and any variation in processing history was unintentional. The general microstructure of the investigated steel was similar and consisted of 85% polygonal ferrite and 15% pearlite. Despite these similarities, they exhibited variation in toughness and were classified as high- and low-toughness steels. Detailed microstructural investigation including stereological analysis and electron microscopy implied that toughness is strongly influenced by mean intercept length of polygonal ferrite and pearlite colony, and their distribution, interlamellar spacing, and degenerated pearlite.

  2. Physical properties and microstructure of Ti(CN)-based cermets with different WC particle size

    International Nuclear Information System (INIS)

    Deng, Ying; Deng, Ling; Xiong, Xiang; Ye, J.W.; Li, P.P.

    2014-01-01

    Ti(CN)-based cermets with different WC particle sizes from 0.2 to 4 μm were prepared at 1450 °C with 2 MPa Air pressure. The microstructure of cermets was investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), Transmission electron microscope (TEM). The results showed that all the cermets with different WC particle sizes have a typical “core–rim” structure. With the increase of WC powder sizes, the frequency and portion of Ti(C 0.7 N 0.3 ) cores and rim are somewhat decreased while the portion of white core is increased, due to the relative dissolution rate decreasing. In addition, the fracture mode of Ti(C,N) based cermets is a mixture of trans-granular (primary) and inter-granular (subordinate) fracture. The TRS (about 1850 MPa) of the cermets fluctuate slightly with the WC particle sizes from 0.2 to 1.0 μm, but decrease evidently with WC particle sizes up to 2 μm

  3. The Microstructure Evolution of Dual-Phase Pipeline Steel with Plastic Deformation at Different Strain Rates

    Science.gov (United States)

    Ji, L. K.; Xu, T.; Zhang, J. M.; Wang, H. T.; Tong, M. X.; Zhu, R. H.; Zhou, G. S.

    2017-07-01

    Tensile properties of the high-deformability dual-phase ferrite-bainite X70 pipeline steel have been investigated at room temperature under the strain rates of 2.5 × 10-5, 1.25 × 10-4, 2.5 × 10-3, and 1.25 × 10-2 s-1. The microstructures at different amount of plastic deformation were examined by using scanning and transmission electron microscopy. Generally, the ductility of typical body-centered cubic steels is reduced when its stain rate increases. However, we observed a different ductility dependence on strain rates in the dual-phase X70 pipeline steel. The uniform elongation (UEL%) and elongation to fracture (EL%) at the strain rate of 2.5 × 10-3 s-1 increase about 54 and 74%, respectively, compared to those at 2.5 × 10-5 s-1. The UEL% and EL% reach to their maximum at the strain rate of 2.5 × 10-3 s-1. This phenomenon was explained by the observed grain structures and dislocation configurations. Whether or not the ductility can be enhanced with increasing strain rates depends on the competition between the homogenization of plastic deformation among the microconstituents (ultra-fine ferrite grains, relatively coarse ferrite grains as well as bainite) and the progress of cracks formed as a consequence of localized inconsistent plastic deformation.

  4. Evolution of microstructural defects with strain effects in germanium nanocrystals synthesized at different annealing temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Minghuan; Cai, Rongsheng; Zhang, Yujuan; Wang, Chao [The Cultivation Base for State Key Laboratory, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); College of Chemistry and Chemical Engineering, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); Wang, Yiqian, E-mail: yqwang@qdu.edu.cn [The Cultivation Base for State Key Laboratory, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); College of Physics Science, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); Ross, Guy G.; Barba, David [INRS-EMT, 1650 Boulevard Lionel-Boulet, Varennes, Quebec J3X 1S2 (Canada)

    2014-07-01

    Ge nanocrystals (Ge-ncs) were produced by implantation of {sup 74}Ge{sup +} into a SiO{sub 2} film on (100) Si, followed by high-temperature annealing from 700 °C to 1100 °C. Transmission electron microscopy (TEM) studies show that the average size of Ge-ncs increases with the annealing temperature. High-resolution TEM (HRTEM) investigations reveal the presence of planar and linear defects in the formed Ge-ncs, whose relative concentrations are determined at each annealing temperature. The relative concentration of planar defects is almost independent of the annealing temperature up to 1000 °C. However, from 1000 °C to 1100 °C, its concentration decreases dramatically. For the linear defects, their concentration varies considerably with the annealing temperatures. In addition, by measuring the interplanar spacing of Ge-ncs from the HRTEM images, a strong correlation is found between the dislocation percentage and the stress field intensity. Our results provide fundamental insights regarding both the presence of microstructural defects and the origin of the residual stress field within Ge-ncs, which can shed light on the fabrication of Ge-ncs with quantified crystallinity and appropriate size for the advanced Ge-nc devices. - Highlights: • Growth of Ge nanocrystals at different annealing temperatures was investigated. • Strain field has great effects on the formation of dislocations. • Different mechanisms are proposed to explain growth regimes of Ge nanocrystals.

  5. Investigation on Microstructure and Impact Toughness of Different Zones in Duplex Stainless Steel Welding Joint

    Science.gov (United States)

    Zhang, Zhiqiang; Jing, Hongyang; Xu, Lianyong; Han, Yongdian; Li, Guolu; Zhao, Lei

    2017-01-01

    This paper investigated on microstructure and impact toughness of different zones in duplex stainless steel welding joint. High-temperature heat-affected zone (HTHAZ) contained coarse ferrite grains and secondary precipitates such as secondary austenite, Cr2N, and sigma. Intergranular secondary austenite was prone to precipitation in low-temperature heat-affected zone (LTHAZ). Both in weld metal (WM) and in HTHAZ, the austenite consisted of different primary and secondary austenite. The ferrite grains in base metal (BM) presented typical rolling texture, while the austenite grains showed random orientation. Both in the HTHAZ and in the LTHAZ, the ferrite grains maintained same texture as the ferrite in the BM. The secondary austenite had higher Ni but lower Cr and Mo than the primary austenite. Furthermore, the WM exhibited the highest toughness because of sufficient ductile austenite and unapparent ferrite texture. The HTHAZ had the lowest toughness because of insufficient austenite formation in addition to brittle sigma and Cr2N precipitation. The LTHAZ toughness was higher than the BM due to secondary austenite precipitation. In addition, the WM fracture was dominated by the dimple, while the cleavage was main fracture mode of the HTHAZ. Both BM and LTHAZ exhibited a mixed fracture mode of the dimple and quasi-cleavage.

  6. The microstructure and mechanical properties of multilayer diamond-like carbon films with different modulation ratios

    International Nuclear Information System (INIS)

    Xu Zhaoying; Zheng, Y.J.; Jiang, F.; Leng, Y.X.; Sun Hong; Huang Nan

    2013-01-01

    Highlights: ► The multilayer DLC films with different modulation ratios have been fabricated by FCVA. ► The multilayer DLC films can effectively decrease the residual stress of the DLC films. ► The multilayer DLC film with modulation ratio of 1:1 shows the best wear resistance. - Abstract: The multilayer DLC films consisting of sp 2 -rich DLC layers (soft DLC) and sp 3 -rich DLC layers (hard DLC) with different modulation ratios (thickness ratio of the hard DLC to soft DLC) ranging from 2:1, 1:1 to 1:2 had been deposited on Si (1 0 0) wafer and Ti–6Al–4V alloy substrates by filtered cathodic vacuum arc (FCVA) deposition. The effect of modulation ratio on the microstructure and properties of the multilayer DLC films including sp 3 content, residual stress, mechanical properties, adhesion strength and wear resistance were studied by Raman spectroscopy, profilometry technique, nanoindenter, Vickers indentation test, scanning electron microscopy (SEM) and ball-on-disc reciprocating friction test. The results showed that the sp 3 content and the hardness of the multilayer DLC films decreased with modulation ratios decreasing. The stress of the multilayer DLC films could be effectively reduced and the stress decreased with the modulation ratio decreasing. The multilayer DLC film with modulation ratio of 1:1 had the best wear resistance due to a balance between hardness and residual stress.

  7. Comparison Study on the Microstructure of Nanocrystalline TiO2 in Different Ti-Si Binary Oxides

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Three different Ti-Si oxide structuares, silica supported titania, silica coated titania and intimately mixed silicatitania, containing 10%-40% SiO2, were made by sol-gel process. The variations of microstructure parameters of nanocrystalline (nc) TiO2-anatase in the three kirds of binary oxides, including in-plane spacing d, cell constants (a0, CQ), cell volume V, cell axial ratio c0/a0 and crystal grain size, were comparatively investigated by high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). It is found that the microstructure parameters vary remarkably with increasing SiO2 content and annealing temperature. Different structured Ti-Si binary oxides lead to different variation tendencies of microstructure parameters. The more SiO2 the binary oxide contains, the more lattice defects of nc TiO2-anatase appear; diffusion or migration of Si cations could be an important influential factor in the variations of microstructure. The grain size of nc TiO2 in the three kinds of binary oxides not only depends on SiO2 content and annealing temperature but also on the degree of lattice microstrain and distortion of nc TiO2-anatase. Both grain size and phase transformation of nc TiO2-anatase are effectively inhibited with increasing SiOa content.

  8. Microstructural characterization of the HAZ of the AISI 439 with different heat input

    International Nuclear Information System (INIS)

    Silva, Lorena de Azevedo; Lima, Luciana Iglesias Lourenco; Campos, Wagner Reis da Costa

    2007-01-01

    Ferritic stainless steels have certain useful corrosion properties, such as resistance to chloride, corrosion in oxidizing aqueous media, oxidation at high temperatures, etc. It is suitable for the aqueous chloride environments, heat transfer applications, condenser tubing for fresh water power plants, industrial buildings, and recently, the ferritic stainless steels have also received attention owing to its superior performance under irradiation. Sometimes in these applications the use of welding processes is necessary. The object of the present work was to research the relationship between microstructure and microhardness in the heat affect zone (HAZ) of the AISI 439, for two different heat input. The base metal shows a random distribution of the precipitates. The HAZ size, grain size, and the amount of precipitates had increased to the bigger heat input weld. The precipitation occurred in bigger amount in the sample with greater heat input, had increased the microhardness. It was observed that the grain size is related with heat input, and that the microhardness is more strong related with other feature, as carbides and nitrites precipitation. (author)

  9. Impact of microstructure evolution on the difference between geometric and reactive surface areas in natural chalk

    Science.gov (United States)

    Yang, Y.; Bruns, S.; Stipp, S. L. S.; Sørensen, H. O.

    2018-05-01

    The coupling between flow and mineral dissolution drives the evolution of many natural and engineered flow systems. Pore surface changes as microstructure evolves but this transient behaviour has traditionally been difficult to model. We combined a reactor network model with experimental, greyscale tomography data to establish the morphological grounds for differences among geometric, reactive and apparent surface areas in dissolving chalk. This approach allowed us to study the effects of initial geometry and macroscopic flow rate independently. The simulations showed that geometric surface, which represents a form of local transport heterogeneity, increases in an imposed flow field, even when the porous structure is chemically homogeneous. Hence, the fluid-reaction coupling leads to solid channelisation, which further results in fluid focusing and an increase in geometric surface area. Fluid focusing decreases the area of reactive surface and the residence time of reactant, both contribute to the over-normalisation of reaction rate. In addition, the growing and merging of microchannels, near the fluid entrance, contribute to the macroscopic, fast initial dissolution rate of rocks.

  10. Effect of different stages of deformation on the microstructure evolution of Ti-rich NiTi shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Tadayyon, Ghazal, E-mail: Ghazal.tadayyon@gmail.com [Department of Metallurgical and Materials Engineering, Faculty of Engineering, Ferdowsi University of Mashhad (Iran, Islamic Republic of); Centre for Research in Medical Devices (CURAM), National University of Ireland, Galway (Ireland); Guo, Yina, E-mail: Yina.Guo@ul.ie [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Mazinani, Mohammad, E-mail: mazinani@um.ac.ir [Department of Metallurgical and Materials Engineering, Faculty of Engineering, Ferdowsi University of Mashhad (Iran, Islamic Republic of); Zebarjad, Seyed Mojtaba, E-mail: mojtabazebarjad@shirazu.ac.ir [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Tiernan, Peter, E-mail: Peter.Tiernan@ul.ie [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Tofail, Syed A.M., E-mail: Tofail.Syed@ul.ie [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Biggs, Manus J.P., E-mail: manus.biggs@nuigalway.ie [Centre for Research in Medical Devices (CURAM), National University of Ireland, Galway (Ireland)

    2017-03-15

    The main objective of this work was to investigate the thermomechanical behavior and microstructural changes of a Ti-rich NiTi shape memory alloy (SMA). The microstructural and texture evolution of aged NiTi alloy at different degrees of deformation were elicited by transmission electron microscopy (TEM). An effort was made to correlate results obtained from the tensile test with results from microstructure studies. The undeformed sample reveals a self-accommodated morphology with straight and well defined twin boundaries. At different stages of deformation, diverse mechanisms were involved. These mechanisms include marstraining, detwinning accompanied by dislocation movement, and finally, severe plastic deformation, subdivision and amorphization of the matrix. Under increasing strains, high density lattice defects were generated and the morphology of B19’ became disordered. - Graphical abstract: The summary of microstructure changes of the martensite twins during tensile deformation in polycrystalline NiTi SMAs. - Highlights: • Initial elastic response, dislocation avalanche and deformation bands were studied. • < 011 > Type II twin accompanied by detwinned area after 2% cold work was observed. • Visible parallel fine stacking faults showed plastic flow of the material. • At higher strains, subgrains changed to recrystallized, finely amorphous structure.

  11. Microstructure and wear resistance of laser cladded composite coatings prepared from pre-alloyed WC-NiCrMo powder with different laser spots

    Science.gov (United States)

    Yao, Jianhua; Zhang, Jie; Wu, Guolong; Wang, Liang; Zhang, Qunli; Liu, Rong

    2018-05-01

    The distribution of WC particles in laser cladded composite coatings can significantly affect the wear resistance of the coatings under aggressive environments. In this study, pre-alloyed WC-NiCrMo powder is deposited on SS316L via laser cladding with circular spot and wide-band spot, respectively. The microstructure and WC distribution of the coatings are investigated with optical microscope (OM), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and X-ray diffraction (XRD). The wear behavior of the coatings is investigated under dry sliding-wear test. The experimental results show that the partially dissolved WC particles are uniformly distributed in both coatings produced with circular spot and wide-band spot, respectively, and the microstructures consist of WC and M23C6 carbides and γ-(Ni, Fe) solid solution matrix. However, due to Fe dilution, the two coatings have different microstructural characteristics, resulting in different hardness and wear resistance. The wide-band spot laser prepared coating shows better performance than the circular spot laser prepared coating.

  12. Microstructural, mechanical and electrochemical behaviour of a 7017 Al–Zn–Mg alloy of different tempers

    Energy Technology Data Exchange (ETDEWEB)

    Rout, Prasanta Kumar, E-mail: prasantonnet55@yahoo.com; Ghosh, M.M.; Ghosh, K.S., E-mail: ksghosh2001@yahoo.co.uk

    2015-06-15

    The aim of the investigation is to assess the microstructural features and associated physical, mechanical and electrochemical properties of a 7017 Al–Zn–Mg alloy of various tempers. A 7017 Al–Zn–Mg alloy was subjected to different ageing schedules to produce under-(T4), peak-(T6), over-(T7) and highly over-aged tempers. Optical microscopy, hardness measurement, electrical conductivity measurement, tensile testing and SEM fractographs, differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and electrochemical polarization studies have been used to characterize the alloy tempers. Hardness measurement and tensile testing showed the characteristic age hardening phenomenon of aluminium alloys. Optical and TEM micrographs have revealed the variation in size of matrix strengthening η′ (MgZn{sub 2}) and also the size and distribution of grain boundary η (MgZn{sub 2}) precipitate with ageing time. DSC thermograms exhibiting exothermic and endothermic peaks indicated the characteristic solid state reaction sequence of the 7017 alloy. Potentiodynamic polarization study of the 7017 alloy of various tempers in 3.5 wt.% NaCl solution at near neutral pH showed typical active metal dissolution behaviour, but at pH 12 an active–passive–transpassive transition behaviour has been observed. - Graphical abstract: TEM micrograph of the 7017 aluminium alloy of various tempers (a, b) under aged (T4), (c, d) peak aged (T6), (e, f) over aged (T7) and (g, h) highly over-aged. Display Omitted - Highlights: • 7017 Al-Zn-Mg alloy was subjected to different artificial ageing treatments. • Characterization of 7017 alloy tempers by hardness, tensile, DSC, TEM and electrochemical behaviour. • Structure-properties relationship of the 7017 Al-Zn-Mg alloy of various tempers.

  13. Influence of different cooling rates on the microstructure of the HAZ and welding CCT diagram of CLAM steel

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Shuhui, E-mail: shzheng@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); Wu Qingsheng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); Huang Qunying [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui, 230027 (China); Liu Shaojun; Han Yangyang [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China)

    2011-10-15

    The evolution of microstructure in the weld HAZ (Heat Affected Zone) under welding thermal cycle was simulated by Gleeble-1500. The microstructures and properties of HAZ at different cooling rates were investigated by optical microscopy (OM), scanning electron microscopy (SEM) and microhardness test. The results showed that when the cooling rates ranged from 3600 K/min to 60 K/min, fully martensitic transformations were achieved, and the cooling rates had little influence on the microstructure and microhardness of martensite. The maximum cooling rate to form ferrite was 60 K/min. When the cooling rates ranged from 60 K/min to 1 K/min, the microhardness of the HAZ began to decrease due to the presence of ferrite, and the lath sizes grew up to 0.13-0.15 {mu}m. The critical cooling rate to gain fully ferrite was found to be slower than 1 K/min. The welding CCT diagram of CLAM steel was constructed and it showed that there were ferrite and martensite transformation regions only. The diagram made it possible to predict the microstructures and properties of HAZ and became an important tool to evaluate weldability of CLAM steel.

  14. Influence of different cooling rates on the microstructure of the HAZ and welding CCT diagram of CLAM steel

    International Nuclear Information System (INIS)

    Zheng Shuhui; Wu Qingsheng; Huang Qunying; Liu Shaojun; Han Yangyang

    2011-01-01

    The evolution of microstructure in the weld HAZ (Heat Affected Zone) under welding thermal cycle was simulated by Gleeble-1500. The microstructures and properties of HAZ at different cooling rates were investigated by optical microscopy (OM), scanning electron microscopy (SEM) and microhardness test. The results showed that when the cooling rates ranged from 3600 K/min to 60 K/min, fully martensitic transformations were achieved, and the cooling rates had little influence on the microstructure and microhardness of martensite. The maximum cooling rate to form ferrite was 60 K/min. When the cooling rates ranged from 60 K/min to 1 K/min, the microhardness of the HAZ began to decrease due to the presence of ferrite, and the lath sizes grew up to 0.13-0.15 μm. The critical cooling rate to gain fully ferrite was found to be slower than 1 K/min. The welding CCT diagram of CLAM steel was constructed and it showed that there were ferrite and martensite transformation regions only. The diagram made it possible to predict the microstructures and properties of HAZ and became an important tool to evaluate weldability of CLAM steel.

  15. Phenolic Compositions and Antioxidant Activities Differ Significantly among Sorghum Grains with Different Applications

    Directory of Open Access Journals (Sweden)

    Shuyu Shen

    2018-05-01

    Full Text Available Sorghum grains with different applications had different phenolic profiles, which were corresponded to various antioxidant capacities. In this study, total phenolic, proanthocyanidins and flavonoids contents, as well as contents of individual phenolic compounds from sorghum grains with various applications were determined, and their antioxidant capacities were evaluated. Total phenolic contents (TPC and total proanthocyanidins contents (TPAC showed strong correlation with antioxidant activities (r > 0.95, p < 0.01. Hongyingzi (S-1, one of the brewing sorghums, showed the highest level of TPC and TPAC, while white grain sorghum (S-8 had the lowest. Except for black grain sorghum (S-7, that contained the highest contents of ferulic acid, brewing sorghum grains contained the higher contents of the most individual phenolic compounds, especially the variety S-1. The correlation among individual phenolic compounds and antioxidant activities indicated that the free forms of protocatechuic acid (r = 0.982 of FRAPassay, p < 0.01 and taxifolin (r = 0.826 of FRAP assay, p < 0.01 may be the main functional compounds. These results indicate that brewing sorghum grains can also be utilized as effective materials for functional foods.

  16. Production, microstructure and mechanical properties of two different austenitic ODS steels

    Science.gov (United States)

    Gräning, T.; Rieth, M.; Hoffmann, J.; Möslang, A.

    2017-04-01

    This article is to summarize and examine processing parameters of novel developed austenitic oxide dispersed strengthened (ODS) steels. Comparing hot-rolled and extruded conditions after the same degree of deformation after and before annealing, are just some examples to give insights into the complex processing of austenitic ODS steels. One of the major drawbacks of the material is the more sophisticated production process. Due to a ductile matrix material with an increased stickiness during milling, a two-step milling procedure with the use of ZrO2 milling balls was applied to raise the production yield and to use the abrasion of the ZrO2 as an additional element to facilitate the formation of nano-sized precipitates. To get a better understanding how the different powder particle sizes after milling affect final properties, sieving was applied and revealed a serious effect in terms of precipitate size, distribution and mechanical properties. Grain sizes in relation to the precipitate size, annealing time and processing parameters were determined and compared to the mechanical properties. Hardness and tensile test have pointed out, that the precipitate size and number are more important in respect to the ultimate tensile strength than the grain size and that in this study hot-rolled material exhibited the better properties. The investigation of the microstructure illustrated the stability of precipitates during annealing at 1100 °C for 40 h. These heat treatments also led to a consistent grain size, due to the pinning effect of the grain boundaries, caused by precipitates.

  17. Electrochemical Investigation of the Corrosion of Different Microstructural Phases of X65 Pipeline Steel under Saturated Carbon Dioxide Conditions

    Directory of Open Access Journals (Sweden)

    Yuanfeng Yang

    2015-05-01

    Full Text Available The aim of this research was to investigate the influence of metallurgy on the corrosion behaviour of separate weld zone (WZ and parent plate (PP regions of X65 pipeline steel in a solution of deionised water saturated with CO2, at two different temperatures (55 °C and 80 °C and at initial pH~4.0. In addition, a non-electrochemical immersion experiment was also performed at 80 °C in CO2, on a sample portion of X65 pipeline containing part of a weld section, together with adjacent heat affected zones (HAZ and parent material. Electrochemical impedance spectroscopy (EIS was used to evaluate the corrosion behaviour of the separate weld and parent plate samples. This study seeks to understand the significance of the different microstructures within the different zones of the welded X65 pipe in CO2 environments on corrosion performance; with particular attention given to the formation of surface scales; and their composition/significance. The results obtained from grazing incidence X-ray diffraction (GIXRD measurements suggest that, post immersion, the parent plate substrate is scale free, with only features arising from ferrite (α-Fe and cementite (Fe3C apparent. In contrast, at 80 °C, GIXRD from the weld zone substrate, and weld zone/heat affected zone of the non-electrochemical sample indicates the presence of siderite (FeCO3 and chukanovite (Fe2CO3(OH2 phases. Scanning Electron Microscopy (SEM on this surface confirmed the presence of characteristic discrete cube-shaped crystallites of siderite together with plate-like clusters of chukanovite.

  18. Effects of different casting mould cooling rates on microstructure and properties of sand-cast Al-7.5Si-4Cu alloy

    Directory of Open Access Journals (Sweden)

    Liu Guanglei

    2013-11-01

    Full Text Available In this work, Al-7.5Si-4Cu alloy melt modified by Al-10Sr, RE and Al-5Ti-B master alloys was poured into multi-step moulds made from three moulding sands, including quartz, alumina and chromite, to investigate comparatively the effects of different cooling rates of the casting mould on the alloy's microstructures and mechanical properties. The results show that with an increase in wall thickness, the cooling rate decreases, the dendrite arm spacing (DAS increases significantly and the mechanical properties decrease steadily. The elongation is more sensitive to the cooling rate than the tensile strength. No obvious trend of the effect of wall thickness on hardness of the alloy was found. When the cooling rate is at its greatest, the microstructures and mechanical properties are the best when using chromite sand. The improvement of the properties is mainly attributed to the decrease of the DAS, the grain refinement and the metamorphic effect. Each of the three has a strong impact on the microstructures. Furthermore, a series of fitting models was established based on the data of the DAS to predict the mechanical properties of the multivariate sand-cast Al-7.5Si-4Cu alloy.

  19. Effect of Thermomechanical Processing on Microstructure, Texture Evolution, and Mechanical Properties of Al-Mg-Si-Cu Alloys with Different Zn Contents

    Science.gov (United States)

    Wang, X. F.; Guo, M. X.; Chen, Y.; Zhu, J.; Zhang, J. S.; Zhuang, L. Z.

    2017-07-01

    The effect of thermomechanical processing on microstructure, texture evolution, and mechanical properties of Al-Mg-Si-Cu alloys with different Zn contents was studied by mechanical properties, microstructure, and texture characterization in the present study. The results show that thermomechanical processing has a significant influence on the evolution of microstructure and texture and on the final mechanical properties, independently of Zn contents. Compared with the T4P-treated (first preaged at 353 K (80 °C) for 12 hours and then naturally aged for 14 days) sheets with high final cold rolling reduction, the T4P-treated sheets with low final cold rolling reduction possess almost identical strength and elongation and higher average r values. Compared with the intermediate annealed sheets with high final cold rolling reduction, the intermediate annealed sheets with low final cold rolling reduction contain a higher number of particles with a smaller size. After solution treatment, in contrast to the sheets with high final cold rolling reduction, the sheets with low final cold rolling reduction possess finer grain structure and tend to form a weaker recrystallization texture. The recrystallization texture may be affected by particle distribution, grain size, and final cold rolling texture. Finally, the visco-plastic self-consistent (VPSC) model was used to predict r values.

  20. Different Functional and Microstructural Changes Depending on Duration of Mild Cognitive Impairment in Parkinson Disease.

    Science.gov (United States)

    Shin, N-Y; Shin, Y S; Lee, P H; Yoon, U; Han, S; Kim, D J; Lee, S-K

    2016-05-01

    disease with mild cognitive impairment according to the duration of parkinsonism before mild cognitive impairment. The functional and microstructural substrates may topographically differ depending on the rate of cognitive decline in these patients. © 2016 by American Journal of Neuroradiology.

  1. The microstructure of MX-80 clay with respect to its bulk physical properties under different environmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, R. [Geodevelopment AB, Lund (Sweden)

    2001-03-01

    microstructure represent two possible stages in long term alteration of the KBS3 buffer clay. One of them has been exposed to repository-like conditions and has a smectite content of up to 25 % and is not much more permeable than MX-80 clay. The other is assumed to have been converted from smectite-rich bentonite to illite by being exposed to such conditions for millions of years and has a higher conductivity. The different hydraulic properties are explained by the different microstructural constitutions.

  2. The microstructure of MX-80 clay with respect to its bulk physical properties under different environmental conditions

    International Nuclear Information System (INIS)

    Pusch, R.

    2001-03-01

    possible stages in long term alteration of the KBS3 buffer clay. One of them has been exposed to repository-like conditions and has a smectite content of up to 25 % and is not much more permeable than MX-80 clay. The other is assumed to have been converted from smectite-rich bentonite to illite by being exposed to such conditions for millions of years and has a higher conductivity. The different hydraulic properties are explained by the different microstructural constitutions

  3. Phase and Micro-Structural Characterization of Sanitary-Ware Fired at Different Temperature

    OpenAIRE

    ATHER HASSAN; YASEEN IQBAL; SYED ZAFAR ILYAS

    2017-01-01

    The three main ingredients of sanitary-ware are clay, feldspar and quartz. This ware is being widely used and has therefore, attracted the attention of researchers from time to time. Consequently, it has been extensively investigated. The present study describes the phase and micro-structural analysis of sanitary-ware samples collected from local (Durr Ceramics Peshawar) industry. XRD (X-Ray Diffraction) of samples fired at 1100oC reveals the presence of ? ? ? ? ?-quartz and primary mullite o...

  4. Deformation microstructures

    DEFF Research Database (Denmark)

    Hansen, N.; Huang, X.; Hughes, D.A.

    2004-01-01

    Microstructural characterization and modeling has shown that a variety of metals deformed by different thermomechanical processes follows a general path of grain subdivision, by dislocation boundaries and high angle boundaries. This subdivision has been observed to very small structural scales...... of the order of 10 nm, produced by deformation under large sliding loads. Limits to the evolution of microstructural parameters during monotonic loading have been investigated based on a characterization by transmission electron microscopy. Such limits have been observed at an equivalent strain of about 10...

  5. Effects of different inoculants on the microstructural characteristics of gray cast iron gg-25, hardness and useful life of tools

    Directory of Open Access Journals (Sweden)

    Diego Ruben Martin

    2015-10-01

    Full Text Available Current study evaluated the machinability characteristics of parts, microstructure and mechanical properties when three different inoculants (IM-22 with FeSi-Ba/Zr; G-20 and FeSi-Ba; IMSR 75 with FeSi-Sr were added in experiments carried out in a foundry. The research methodology was mailly based on the analysis of the machinability by the milling process of the specimens in gray cast iron GG-25, name according to DIN EN 1561.Evaluation of results is based on a thorough analysis of tool wear, surface finish, microstructural analysis, chemical composition and mechanical properties of the material. Results showed that among the studied inoculants strontium sulfide (SrS was thermodynamically more stable than the others, because it leds towards a more negative free energy change of Gibbs and therefore more favorable to the formation of nuclei having greater critical radius (rc, solidification with heterogeneous nucleation. Its inoculant was also more efficient in forming a more favorable microstructure, greater amounts of eutectic cells and, longer life of the insert when machined.

  6. Microstructural characterization of weld joints of 9Cr reduced activation ferritic martensitic steel fabricated by different joining methods

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Paul, V.; Saroja, S.; Albert, S.K.; Jayakumar, T.; Rajendra Kumar, E., E-mail: vtp@igcar.gov.in

    2014-10-15

    This paper presents a detailed electron microscopy study on the microstructure of various regions of weldment fabricated by three welding methods namely tungsten inert gas welding, electron beam welding and laser beam welding in an indigenously developed 9Cr reduced activation ferritic/martensitic steel. Electron back scatter diffraction studies showed a random micro-texture in all the three welds. Microstructural changes during thermal exposures were studied and corroborated with hardness and optimized conditions for the post weld heat treatment have been identified for this steel. Hollomon–Jaffe parameter has been used to estimate the extent of tempering. The activation energy for the tempering process has been evaluated and found to be corresponding to interstitial diffusion of carbon in ferrite matrix. The type and microchemistry of secondary phases in different regions of the weldment have been identified by analytical transmission electron microscopy. - Highlights: • Comparison of microstructural parameters in TIG, electron beam and laser welds of RAFM steel • EBSD studies to illustrate the absence of preferred orientation and identification of prior austenite grain size using phase identification map • Optimization of PWHT conditions for indigenous RAFM steel • Study of kinetics of tempering and estimation of apparent activation energy of the process.

  7. Characteristics of microstructure and tritium release properties of different kinds of beryllium pebbles for application in tritium breeding modules

    Energy Technology Data Exchange (ETDEWEB)

    Kurinskiy, P., E-mail: petr.kurinskiy@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials – Applied Materials Physics (IAM-AWP), P.O. Box 3640, Karlsruhe 76021 (Germany); Vladimirov, P.; Moeslang, A. [Karlsruhe Institute of Technology, Institute for Applied Materials – Applied Materials Physics (IAM-AWP), P.O. Box 3640, Karlsruhe 76021 (Germany); Rolli, R. [Karlsruhe Institute of Technology, Institute for Applied Materials – Materials and Biomechanics (IAM-WBM), P.O. Box 3640, Karlsruhe 76021 (Germany); Zmitko, M. [The European Joint Undertaking for ITER and the Development of Fusion Energy, c/Josep Pla, no. 2, Torres Diagonal Litoral, Edificio B3, Barcelona 08019 (Spain)

    2014-10-15

    Highlights: • Tritium release properties and characteristics of microstructure of beryllium pebbles having different sizes of grains were studied. • Fine-grained beryllium pebbles showed the best ability to release tritium compared to pebbles from another charges. • Be pebbles with the grain sizes exceeding 100 μm contain a great number of small pores and inclusions presumably referring to the history of material fabrication. • The sizes of grains are one of a key characteristic of microstructure which influences the parameters of tritium release. - Abstract: Beryllium pebbles with diameters of 1 mm are considered to be perspective material for the use as neutron multiplier in tritium breeding modules of fusion reactors. Up to now, the design of helium-cooled breeding blanket in ITER project foresees the use of 1 mm beryllium pebbles fabricated by NGK Insulators Ltd., Japan. It is notable that beryllium pebbles from Russian Federation and USA are also available and the possibility of their large-scale fabrication is under study. Presented work is dedicated to a study of characteristics of microstructure and parameters of tritium release of beryllium pebbles produced by Bochvar Institute, Russian Federation, and Materion Corporation, USA.

  8. Different microstructures of mobile twin boundaries in 10 M modulated Ni-Mn-Ga martensite

    Czech Academy of Sciences Publication Activity Database

    Heczko, Oleg; Straka, L.; Seiner, Hanuš

    2013-01-01

    Roč. 61, č. 2 (2013), 622-631 ISSN 1359-6454 R&D Projects: GA ČR GAP107/10/0824; GA ČR(CZ) GAP107/11/0391 Institutional support: RVO:68378271 ; RVO:61388998 Keywords : martensitic twin microstructure * twinning interfaces * Ni-Mn-Ga martensite * mobility of twin boundary * magnetic shape memory Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.940, year: 2013 http://www.sciencedirect.com/science/article/pii/S135964541200732X

  9. Microstructural asymmetry of the corticospinal tracts predicts right-left differences in circle drawing skill in right-handed adolescents

    OpenAIRE

    Angstmann, Steffen; Madsen, Kathrine Skak; Skimminge, Arnold; Jernigan, Terry L; Baaré, William F C; Siebner, Hartwig Roman

    2016-01-01

    © 2016, The Author(s). Most humans show a strong preference to use their right hand, but strong preference for the right hand does not necessarily imply a strong right–left asymmetry in manual proficiency (i.e., dexterity). Here we tested the hypothesis that intra-individual asymmetry of manual proficiency would be reflected in microstructural differences between the right and left corticospinal tract (CST) in a cohort of 52 right-handed typically-developing adolescents (11–16 years). Partici...

  10. Microstructural research on hot strips of low carbon steel produced by a compact strip production line under different thermal histories

    International Nuclear Information System (INIS)

    Yu Hao; Chen Qixiang; Kang Yonglin; Sun Yi

    2005-01-01

    Coupons with the same composition and thickness (4.0 mm nominal gauge) obtained from hot strips of low carbon steel underwent a series of investigations to analyze the microstructural characteristics and mechanisms responsible for their differences in mechanical properties. Two different industrial technologies were adopted, although the strips used in this research were produced on the same Compact Strip Production (CSP) line. One of the strips was produced with a routine γ→α CSP thermal history, but the other with a γ→α→γ* conventional thermal history. The only difference between them was that one technology had a α→γ* thermal history. Different specimens of both types of strips were prepared for metallographic observation, tensile tests, electron back-scattered diffraction tests and positron annihilation technique tests. Experimental results showed that the differences in mechanical properties could be ascribed to dissimilarities not only in the grain size and textural components but also in dislocation density

  11. Quantitatively characterizing the microstructural features of breast ductal carcinoma tissues in different progression stages by Mueller matrix microscope.

    Science.gov (United States)

    Dong, Yang; Qi, Ji; He, Honghui; He, Chao; Liu, Shaoxiong; Wu, Jian; Elson, Daniel S; Ma, Hui

    2017-08-01

    Polarization imaging has been recognized as a potentially powerful technique for probing the microstructural information and optical properties of complex biological specimens. Recently, we have reported a Mueller matrix microscope by adding the polarization state generator and analyzer (PSG and PSA) to a commercial transmission-light microscope, and applied it to differentiate human liver and cervical cancerous tissues with fibrosis. In this paper, we apply the Mueller matrix microscope for quantitative detection of human breast ductal carcinoma samples at different stages. The Mueller matrix polar decomposition and transformation parameters of the breast ductal tissues in different regions and at different stages are calculated and analyzed. For more quantitative comparisons, several widely-used image texture feature parameters are also calculated to characterize the difference in the polarimetric images. The experimental results indicate that the Mueller matrix microscope and the polarization parameters can facilitate the quantitative detection of breast ductal carcinoma tissues at different stages.

  12. Microstructure, mechanical property and metal release of As-SLM CoCrW alloy under different solution treatment conditions.

    Science.gov (United States)

    Lu, Yanjin; Wu, Songquan; Gan, Yiliang; Zhang, Shuyuan; Guo, Sai; Lin, Junjie; Lin, Jinxin

    2015-03-01

    In the study, the microstructure, mechanical property and metal release behavior of selective laser melted CoCrW alloys under different solution treatment conditions were systemically investigated to assess their potential use in orthopedic implants. The effects of the solution treatment on the microstructure, mechanical properties and metal release were systematically studied by OM, SEM, XRD, tensile test, and ICP-AES, respectively. The XRD indicated that during the solution treatment the alloy underwent the transformation of γ-fcc to ε-hcp phase; the ε-hcp phase nearly dominated in the alloy when treated at 1200°C following the water quenching; the results from OM, SEM showed that the microstructural change was occurred under different solution treatments; solution at 1150°C with furnace cooling contributed to the formation of larger precipitates at the grain boundary regions, while the size and number of the precipitates was decreased as heated above 1100°C with the water quenching; moreover, the diamond-like structure was invisible at higher solution temperature over 1150°C following water quenching; compared with the furnace cooling, the alloy quenched by water showed excellent mechanical properties and low amount of metal release; as the alloy heated at 1200°C, the mechanical properties of the alloy reached their optimum combination at UTS=1113.6MPa, 0.2%YS=639.5MPa, and E%=20.1%, whilst showed the lower total quantity of metal release. It is suggested that a proper solution treatment is an efficient strategy for improving the mechanical properties and corrosion resistance of As-SLM CoCrW alloy that show acceptable tensile ductility. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Thermo-mechanical fatigue behavior of the intermetallic gamma-TiAl alloy TNB-V5 with different microstructures

    International Nuclear Information System (INIS)

    Roth, M; Biermann, H

    2010-01-01

    The cyclic deformation and fatigue behavior of the γ-TiAl alloy TNB-V5 is studied under thermo-mechanical load for the three technically important microstructures Fully-Lamellar (FL), Near-Gamma (NG) and Duplex (DP), respectively. Thus, thermo-mechanical fatigue (TMF) tests were carried out with different temperature-strain cycles, different temperature ranges from 400 0 C to 800 0 C and with two different strain ranges. Cyclic deformation curves, stress-strain hysteresis loops and fatigue lives are presented. The type of microstructure shows a surprisingly small influence on the cyclic deformation and fatigue behavior under TMF conditions. For a general life prediction the damage parameter of Smith, Watson and Topper P SWT is well suitable, if the testing and the application temperature ranges, respectively, include temperatures above the ductile-brittle transition temperature (approx. 750 0 C). If the maximum temperature is below that temperature, the brittle materials' behavior yields a high scatter of fatigue lives and a low slope of the fatigue life curve and therefore the damage parameter P SWT cannot be applied for the live prediction.

  14. Thermo-mechanical fatigue behavior of the intermetallic gamma-TiAl alloy TNB-V5 with different microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Roth, M [now at IAV GmbH, Kauffahrtei 25, D-09120 Chemnitz (Germany); Biermann, H, E-mail: marcel.roth@iav.d [TU Bergakademie Freiberg, Institute for Materials Engineering, Gustav-Zeuner-Strasse 5, D-09599 Freiberg (Germany)

    2010-07-01

    The cyclic deformation and fatigue behavior of the {gamma}-TiAl alloy TNB-V5 is studied under thermo-mechanical load for the three technically important microstructures Fully-Lamellar (FL), Near-Gamma (NG) and Duplex (DP), respectively. Thus, thermo-mechanical fatigue (TMF) tests were carried out with different temperature-strain cycles, different temperature ranges from 400{sup 0}C to 800{sup 0}C and with two different strain ranges. Cyclic deformation curves, stress-strain hysteresis loops and fatigue lives are presented. The type of microstructure shows a surprisingly small influence on the cyclic deformation and fatigue behavior under TMF conditions. For a general life prediction the damage parameter of Smith, Watson and Topper P{sub SWT} is well suitable, if the testing and the application temperature ranges, respectively, include temperatures above the ductile-brittle transition temperature (approx. 750{sup 0}C). If the maximum temperature is below that temperature, the brittle materials' behavior yields a high scatter of fatigue lives and a low slope of the fatigue life curve and therefore the damage parameter P{sub SWT} cannot be applied for the live prediction.

  15. Use of Spent Zeolite Sorbents for the Preparation of Lightweight Aggregates Differing in Microstructure

    Directory of Open Access Journals (Sweden)

    Wojciech Franus

    2017-02-01

    Full Text Available Lightweight aggregates (LWAs made by sintering beidellitic clay deposits at high temperatures, with and without the addition of spent zeolitic sorbents (clinoptilolitic tuff and Na-P1 made from fly ash containing diesel oil, were investigated. Mineral composition of the aggregates determined by X-ray diffraction was highly uniformized in respect of the initial composition of the substrates. The microstructure of the LWAs, which were studied with a combination of mercury porosimetry, microtomography, nitrogen adsorption/desorption isotherms and scanning electron microscopy, was markedly modified by the spent zeolites, which diminished bulk densities, increased porosities and pore radii. The addition of zeolites decreased water absorption and the compressive strength of the LWAs. The spent Na-P1 had a greater effect on the LWAs’ structure than the clinoptilolite.

  16. Microstructure and Dielectric Properties of LPCVD/CVI-SiBCN Ceramics Annealed at Different Temperatures

    Directory of Open Access Journals (Sweden)

    Jianping Li

    2017-06-01

    Full Text Available SiBCN ceramics were introduced into porous Si3N4 ceramics via a low-pressure chemical vapor deposition and infiltration (LPCVD/CVI technique, and then the composite ceramics were heat-treated from 1400 °C to 1700 °C in a N2 atmosphere. The effects of annealing temperatures on microstructure, phase evolution, dielectric properties of SiBCN ceramics were investigated. The results revealed that α-Si3N4 and free carbon were separated below 1700 °C, and then SiC grains formed in the SiBCN ceramic matrix after annealing at 1700 °C through a phase-reaction between free carbon and α-Si3N4. The average dielectric loss of composites increased from 0 to 0.03 due to the formation of dispersive SiC grains and the increase of grain boundaries.

  17. Effects of different cooling rates during two casting processes on the microstructures and mechanical properties of extruded Mg–Al–Ca–Mn alloy

    International Nuclear Information System (INIS)

    Xu, S.W.; Oh-ishi, K.; Kamado, S.; Takahashi, H.; Homma, T.

    2012-01-01

    Highlights: ► Ordered monolayer GP zone was formed by increasing cooling rate. ► Finer extruded microstructure was obtained by increasing cooling rate. ► Higher number density precipitates was obtained by increasing cooling rate. ► Tensile 0.2% proof stress was increased by 105 MPa by increasing cooling rate. ► Extruded DC-cast alloy shows higher tensile 0.2% proof stress of 409 MPa. - Abstract: In this study, Mg–3.6Al–3.4Ca–0.3Mn (wt.%) (which is denoted AXM4303) alloy ingots were prepared by two casting processes with different cooling rates: permanent mold (PM) casting, which has a lower cooling rate of 10–20 °C/s and direct chill (DC) casting, which has a higher cooling rate of 100–110 °C/s. Then, these two types of AXM4303 alloy ingots were hot extruded at 400 °C under the same conditions. The microstructures of the as-cast and extruded alloy samples were systematically investigated by field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM) and electron backscattered diffraction (EBSD) systems. The effects of the different cooling rates during the casting process on the microstructures and mechanical properties of the extruded AXM4303 alloy samples were evaluated. The results show that the strength of the extruded Mg–Al–Ca–Mn alloy can be substantially increased by microstructural control during the casting process. Because the cooling rate of the DC casting process is much faster than the cooling rate of PM casting, the DC-cast AXM4303 has the following properties: (i) the lamellar eutectic structure and dendrite cell size are significantly refined, (ii) the ordered monolayer GP zones enriched with Al and Ca nucleate with no growth, and (iii) most of the Mn remains in solution in the matrix. Thus, after hot extrusion, the DC-cast AXM4303 has finer dynamically recrystallized (DRXed) grain size, finer and more uniformly distributed fragmented eutectic particles, finer planar Al 2 Ca precipitates

  18. Estimating significances of differences between slopes: A new methodology and software

    Directory of Open Access Journals (Sweden)

    Vasco M. N. C. S. Vieira

    2013-09-01

    Full Text Available Determining the significance of slope differences is a common requirement in studies of self-thinning, ontogeny and sexual dimorphism, among others. This has long been carried out testing for the overlap of the bootstrapped 95% confidence intervals of the slopes. However, the numerical random re-sampling with repetition favours the occurrence of re-combinations yielding largely diverging slopes, widening the confidence intervals and thus increasing the chances of overlooking significant differences. To overcome this problem a permutation test simulating the null hypothesis of no differences between slopes is proposed. This new methodology, when applied both to artificial and factual data, showed an enhanced ability to differentiate slopes.

  19. Clinical significance of changes of serum osteocalcin (BGP) levels in subjects of different age-groups

    International Nuclear Information System (INIS)

    Jiang Lihua; Zhang Jin; Han Cuihua; Ouyang Qiaohong

    2006-01-01

    Objective: To investigate the changes of serum BGP levels in different age-groups. Methods: Serum BGP levels were determined with RIA in 306 subjects of different age-groups. Results: The serum BGP levels were highest in subjects of the pre-adolescent group (age5-15, n=60, vs other groups, all P 50, n=80, P<0.001). Levels in the middle age group were the lowest and were significantly lower than those in the old age group (P<0.001). No sex related differences were observed in the pre-adolescent and middle age groups, but in the youth group, serum BGP levels were significantly higher in the males than those in the females (P<0.05). However, in the old age group, the reverse was true i.e. values being significantly higher in the females (vs males, P<0.01). Conclusion: Serum BGP levels varied greatly among the different age groups. (authors)

  20. The Ability of Different Imputation Methods to Preserve the Significant Genes and Pathways in Cancer

    Directory of Open Access Journals (Sweden)

    Rosa Aghdam

    2017-12-01

    Full Text Available Deciphering important genes and pathways from incomplete gene expression data could facilitate a better understanding of cancer. Different imputation methods can be applied to estimate the missing values. In our study, we evaluated various imputation methods for their performance in preserving significant genes and pathways. In the first step, 5% genes are considered in random for two types of ignorable and non-ignorable missingness mechanisms with various missing rates. Next, 10 well-known imputation methods were applied to the complete datasets. The significance analysis of microarrays (SAM method was applied to detect the significant genes in rectal and lung cancers to showcase the utility of imputation approaches in preserving significant genes. To determine the impact of different imputation methods on the identification of important genes, the chi-squared test was used to compare the proportions of overlaps between significant genes detected from original data and those detected from the imputed datasets. Additionally, the significant genes are tested for their enrichment in important pathways, using the ConsensusPathDB. Our results showed that almost all the significant genes and pathways of the original dataset can be detected in all imputed datasets, indicating that there is no significant difference in the performance of various imputation methods tested. The source code and selected datasets are available on http://profiles.bs.ipm.ir/softwares/imputation_methods/.

  1. The Ability of Different Imputation Methods to Preserve the Significant Genes and Pathways in Cancer.

    Science.gov (United States)

    Aghdam, Rosa; Baghfalaki, Taban; Khosravi, Pegah; Saberi Ansari, Elnaz

    2017-12-01

    Deciphering important genes and pathways from incomplete gene expression data could facilitate a better understanding of cancer. Different imputation methods can be applied to estimate the missing values. In our study, we evaluated various imputation methods for their performance in preserving significant genes and pathways. In the first step, 5% genes are considered in random for two types of ignorable and non-ignorable missingness mechanisms with various missing rates. Next, 10 well-known imputation methods were applied to the complete datasets. The significance analysis of microarrays (SAM) method was applied to detect the significant genes in rectal and lung cancers to showcase the utility of imputation approaches in preserving significant genes. To determine the impact of different imputation methods on the identification of important genes, the chi-squared test was used to compare the proportions of overlaps between significant genes detected from original data and those detected from the imputed datasets. Additionally, the significant genes are tested for their enrichment in important pathways, using the ConsensusPathDB. Our results showed that almost all the significant genes and pathways of the original dataset can be detected in all imputed datasets, indicating that there is no significant difference in the performance of various imputation methods tested. The source code and selected datasets are available on http://profiles.bs.ipm.ir/softwares/imputation_methods/. Copyright © 2017. Production and hosting by Elsevier B.V.

  2. Microstructural stability of a NiAl-Mo eutectic alloy

    International Nuclear Information System (INIS)

    Kush, M.T.; Holmes, J.W.; Gibala, R.

    1999-01-01

    The microstructural stability of a directionally-solidified NiAl-9 at.% Mo quasi-binary alloy was investigated under conditions of thermal cycling between the temperatures 973K and 1,473K utilizing time-temperature heating and cooling profiles which approximate potential engine applications. Two different microstructures were examined: a cellular microstructure in which the faceted second-phase Mo rods in the NiAl matrix formed misaligned cell boundaries which separated aligned cells approximately 0.4 mm in width and 5--25 mm in length, and a nearly fault-free fully columnar microstructure well aligned along the [001] direction. Both microstructures resisted coarsening under thermal cycling, but plastic deformation induced by thermal stresses introduced significant specimen shape changes. Surprisingly, the cellular microstructure, for which the cell boundary region apparently acts as a deformation buffer, exhibited better resistance to thermal fatigue than the more fault-free and better aligned columnar microstructure

  3. Assessment of Choroidal Microstructure and Subfoveal Thickness Change in Eyes With Different Stages of Age-Related Macular Degeneration.

    Science.gov (United States)

    Lu, Linna; Xu, Shiqiong; He, Fangling; Liu, Yan; Zhang, Yidan; Wang, Jing; Wang, Zhiliang; Fan, Xianqun

    2016-03-01

    Age-related macular degeneration (AMD) is a major cause of irreversible blindness. Choroidal structural changes seem to be inevitable in AMD pathogenesis. Our study revealed associated choroidal microstructural changes in AMD eyes.The aim of the study was to compare choroidal microstructural changes in eyes with AMD of different stages.The study was a retrospective, cross-sectional case series.The participants comprised of 32 age-matched normal eyes as controls, and 26 fellow uninvolved eyes of intermediate/late AMD, 29 of early AMD, 28 of intermediate AMD, and 39 of late AMD.All subjects underwent comprehensive ophthalmologic examination. The choroid images, including subfoveal choroidal thickness, percentage of Sattler layer area, and en face images of the choroid, were obtained using spectral-domain optical coherence tomography.The main outcome measures were subfoveal choroidal thickness changes, percentage of Sattler layer area changes, and en face images of the choroid in AMD eyes.One hundred fifty-four eyes of 96 individuals with mean age of 67.1±9.2 years were included. The mean subfoveal choroidal thickness was 295.4 ± 56.8 μm in age-matched normal eyes, 306.7 ± 68.4 μm in fellow uninvolved eyes with AMD, 293.8 ± 80.4 μm in early AMD, 215.6 ± 80.4 μm in intermediate AMD, and 200.4 ± 66.6 μm in late AMD (F = 14.2, all P < 0.001). Choroidal thickness was greater in early AMD eyes than in intermediate/late AMD eyes (P < 0.001). Mean percentage of Sattler layer area in each group showed a similar tendency. Microstructure of the choroid showed reduced vascular density of Sattler layer areas in late AMD eyes compared with normal eyes.Decreasing subfoveal choroidal thickness and percentage of Sattler layer area were demonstrated in the progression of AMD. The choroidal change was related to atrophy of the microstructural changes of underlying capillaries and medium-sized vessels.

  4. Microstructure and properties of sintered silicon carbides fabricated by different methods

    International Nuclear Information System (INIS)

    Maruyama, Tadashi; Kitamura, Hideya; Iseki, Takayoshi

    1986-01-01

    Studies were made of effects of fabrication methods on the properties and microstructure of sintered silicon carbides. The specimens used in this investigation were three kinds of commercially available SiC bodies which were fabricated by reaction bonding, pressureless sintering and hot-pressing. The hot-pressed SiC contained a small amount of BeO. Measurements were carried out on density, the polytype by X-ray diffraction method and 4-point bend strength. Microstructural observation was also carried out using an optical microscope, a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The results of density measurement showed that the open porosities of three specimens were negligibly small and that the density of the hot pressed SiC had nearly the theoretical density. The measurement of 4-point bend strength indicated that the reaction bonded SiC had the highest value and the hot-pressed SiC the lowest. The analysis of the polytype indicated that all the specimens consisted mainly of α-SiC of 6 H type. In the reaction bonded SiC, about 11 % of 3 C type (β-SiC) and 9 % of free Si were recognized. The average grain diameter and fracture mode of each specimen were determined from observation with an optical microscope and SEM. In the hot-pressed SiC, the fracture occurred mainly at grain boundaries, whereas it occurred mostly in grains in the reaction bonded and pressureless sintered SiC. A lot of stacking faults were observed in all the specimens with a TEM. In addition, small closed pores were often recognized in the pressureless sintered SiC. In the hot-pressed SiC, a contrast originated from strain field within grains was observed, and dislocations near grain boundaries were a characteristic feature of this material. Small short partial dislocations accompanied by stacking fault were often observed in the reaction bonded SiC. (author)

  5. Biographical Narratives of Encounter: The Significance of Mobility and Emplacement in Shaping Attitudes towards Difference

    Science.gov (United States)

    Sadgrove, Joanna

    2014-01-01

    This paper is located within work in urban studies about the significance of contact with difference as a means for reducing prejudice and achieving social change. Recent approaches, influenced by theories of affect, have emphasised non-conscious everyday negotiations of difference in the city. In this paper it is argued that such approaches lose sight of the significance of the subject: of the reflective judgements of ‘others’ made by individuals; of our ability to make decisions around the control of our feelings and identifications; and of the significance of personal pasts and collective histories in shaping the ways we perceive and react to encounters. Rather, this paper uses a biographical approach focusing on interviewees’ narratives of encounter. Through its attention to processes of mobility and emplacement, it contributes to debates about when contact with difference matters by highlighting the importance of everyday social normativities in the production of moral dispositions. PMID:26300566

  6. Potential Causes of Significant Inventory Differences at Bulk Handling Facilities and the Importance of Inventory Difference Action Levels

    International Nuclear Information System (INIS)

    Homer, Alan; O’Hagan, Brendan

    2015-01-01

    Accountancy for nuclear material can be split into two categories. Firstly, where possible, accountancy should be in terms of items that can be transferred as discrete packages and their contents fixed at the time of their creation. All items must remain accounted for at all times, and a single missing item is considered significant. Secondly, where nuclear material is unconstrained, for example in a reprocessing plant where it can change form, there is an uncertainty that relates to the amount of material present in any location. Cumulatively, these uncertainties can be summed and provide a context for any estimate of material in a process. Any apparent loss or gain between what has been physically measured within a facility during its physical inventory take and what is reported within its nuclear material accounts is known as an inventory difference. The cumulative measurement uncertainties can be used to set an action level for the inventory difference so that if an inventory difference is observed outside of such action levels, the difference is classified as significant and an investigation to find the root cause(s) is required. The purpose of this paper is to explore the potential causes of significant inventory differences and to provide a framework within which an inventory difference investigation can be carried out.

  7. Microstructure examination of Fe–14Cr ODS ferritic steels produced through different processing routes

    Energy Technology Data Exchange (ETDEWEB)

    Oksiuta, Z., E-mail: z.oksiuta@pb.edu.pl [Bialystok University of Technology, Mechanical Department (Poland); Hosemann, P. [University of California Berkeley, Nuclear Engineering, 4169 Etcheverry Hall, Berkeley, CA 94720 (United States); Vogel, S.C. [Los Alamos Neutron Science Center, Los Alamos National Laboratory, PO Box 1663, NM (United States); Baluc, N. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, Villigen PSI 5232 (Switzerland)

    2014-08-01

    Various thermo-mechanical treatments were applied to refine and homogenise grain size and improve mechanical properties of hot-isostatically pressed (HIP) 14%Cr ODS ferritic steel. The grain size was reduced, improving mechanical properties, tensile strength and Charpy impact, however bimodal-like distribution was also observed. As a result, larger, frequently elongated grains with size above 1 μm and refined, equiaxed grains with a diameter ranging from 250 to 500 nm. Neutron diffraction measurements revealed that for HIP followed by hydrostatic extrusion material the strongest fiber texture was observed oriented parallel to the extrusion direction. In comparison with hot rolling and hot pressing methods, this material exhibited promising mechanical properties: the ultimate tensile strength of 1350 MPa, yield strength of 1280 MPa, total elongation of 21.7% and Charpy impact energy of 5.8 J. Inferior Charpy impact energy of ∼3.0 J was measured for HIP and hot rolled material, emphasising that parameters of this manufacturing process still have to be optimised. As an alternative manufacturing route, due to the uniform microstructure and simplicity of the process, hot pressing might be a promising method for production of smaller parts of ODS ferritic steels. Besides, the ductile-to-brittle transition temperature of all thermo-mechanically treated materials, in comparison with as-HIPped ODS steel, was improved by more than 50%, the transition temperature ranging from 50 to 70 °C (323 and 343 K) remains still unsatisfactory.

  8. Discriminating Yogurt Microstructure Using Diffuse Reflectance Images

    DEFF Research Database (Denmark)

    Skytte, Jacob Lercke; Møller, Flemming; Abildgaard, Otto Højager Attermann

    2015-01-01

    The protein microstructure of many dairy products is of great importance for the consumers’ experience when eating the product. However, studies concerning discrimination between protein microstructures are limited. This paper presents preliminary results for discriminating different yogurt...... microstructures using hyperspectral (500-900nm) diffuse reflectance images (DRIs) – a technique potentially well suited for inline process control. Comparisons are made to quantified measures of the yogurt microstructure observed through confocal scanning laser microscopy (CSLM). The output signal from both...... modalities is evaluated on a 24 factorial design covering four common production parameters, which significantly change the chemistry and the microstructure of the yogurt. It is found that the DRIs can be as discriminative as the CSLM images in certain cases, however the performance is highly governed...

  9. Characterizing the Effects of Washing by Different Detergents on the Wavelength-Scale Microstructures of Silk Samples Using Mueller Matrix Polarimetry.

    Science.gov (United States)

    Dong, Yang; He, Honghui; He, Chao; Zhou, Jialing; Zeng, Nan; Ma, Hui

    2016-08-10

    Silk fibers suffer from microstructural changes due to various external environmental conditions including daily washings. In this paper, we take the backscattering Mueller matrix images of silk samples for non-destructive and real-time quantitative characterization of the wavelength-scale microstructure and examination of the effects of washing by different detergents. The 2D images of the 16 Mueller matrix elements are reduced to the frequency distribution histograms (FDHs) whose central moments reveal the dominant structural features of the silk fibers. A group of new parameters are also proposed to characterize the wavelength-scale microstructural changes of the silk samples during the washing processes. Monte Carlo (MC) simulations are carried out to better understand how the Mueller matrix parameters are related to the wavelength-scale microstructure of silk fibers. The good agreement between experiments and simulations indicates that the Mueller matrix polarimetry and FDH based parameters can be used to quantitatively detect the wavelength-scale microstructural features of silk fibers. Mueller matrix polarimetry may be used as a powerful tool for non-destructive and in situ characterization of the wavelength-scale microstructures of silk based materials.

  10. Characterizing the Effects of Washing by Different Detergents on the Wavelength-Scale Microstructures of Silk Samples Using Mueller Matrix Polarimetry

    Directory of Open Access Journals (Sweden)

    Yang Dong

    2016-08-01

    Full Text Available Silk fibers suffer from microstructural changes due to various external environmental conditions including daily washings. In this paper, we take the backscattering Mueller matrix images of silk samples for non-destructive and real-time quantitative characterization of the wavelength-scale microstructure and examination of the effects of washing by different detergents. The 2D images of the 16 Mueller matrix elements are reduced to the frequency distribution histograms (FDHs whose central moments reveal the dominant structural features of the silk fibers. A group of new parameters are also proposed to characterize the wavelength-scale microstructural changes of the silk samples during the washing processes. Monte Carlo (MC simulations are carried out to better understand how the Mueller matrix parameters are related to the wavelength-scale microstructure of silk fibers. The good agreement between experiments and simulations indicates that the Mueller matrix polarimetry and FDH based parameters can be used to quantitatively detect the wavelength-scale microstructural features of silk fibers. Mueller matrix polarimetry may be used as a powerful tool for non-destructive and in situ characterization of the wavelength-scale microstructures of silk based materials.

  11. Sex differences in associations between white matter microstructure and gonadal hormones in children and adolescents with prenatal alcohol exposure.

    Science.gov (United States)

    Uban, K A; Herting, M M; Wozniak, J R; Sowell, E R

    2017-09-01

    Despite accumulating evidence from animal models demonstrating that prenatal alcohol exposure (PAE) results in life-long neuroendocrine dysregulation, very little is known on this topic among humans with fetal alcohol spectrum disorders (FASD). We expected that alterations in gonadal hormones might interfere with the typical development of white matter (WM) myelination, and in a sex-dependent manner, in human adolescents with FASD. In order to investigate this hypothesis, we used diffusion tensor imaging (DTI) to assess: 1) whether or not sex moderates the impact of PAE on WM microstructure; and 2) how gonadal hormones relate to alterations in WM microstructure in children and adolescents affected by PAE. 61 youth (9 to 16 yrs.; 49% girls; 50% PAE) participated as part of the Collaborative Initiative on Fetal Alcohol Spectrum Disorders (CIFASD). DTI scans and passive drool samples were obtained to examine neurodevelopmental associations with testosterone (T) and dehydroepiandrosterone (DHEA) levels in boys and girls, and estradiol (E2) and progesterone (P) levels in girls. Tract-based spatial statistics were utilized to generate fractional anisotropy (FA) and mean diffusivity (MD) for 9 a priori WM regions of interest (ROIs). As predicted, alterations in FA were observed in adolescents with PAE relative to controls, and these differences varied by sex. Girls with PAE exhibited lower FA (Inferior fronto-occipital and Uncinate fasciculi) while boys with PAE exhibited higher FA (Callosal body, Cingulum, Corticospinal tract, Optic radiation, Superior longitudinal fasciculus) relative to age-matched controls. When gonadal hormone levels were examined in relation to DTI measures, additional group differences in FA were revealed, demonstrating that neuroendocrine factors are associated with PAE-related brain alterations. These findings provide human evidence that PAE relates to sex-specific differences in WM microstructure, and underlying alterations in gonadal hormone

  12. Microstructural asymmetry of the corticospinal tracts predicts right-left differences in circle drawing skill in right-handed adolescents

    DEFF Research Database (Denmark)

    Angstmann, Steffen; Madsen, Kathrine Skak; Skimminge, Arnold

    2016-01-01

    Most humans show a strong preference to use their right hand, but strong preference for the right hand does not necessarily imply a strong right-left asymmetry in manual proficiency (i.e., dexterity). Here we tested the hypothesis that intra-individual asymmetry of manual proficiency would...... be reflected in microstructural differences between the right and left corticospinal tract (CST) in a cohort of 52 right-handed typically-developing adolescents (11-16 years). Participants were asked to fluently draw superimposed circles with their right dominant and left non-dominant hand. Temporal regularity...... of circle drawing movements was assessed for each hand using a digitizing tablet. Although all participants were right-handed, there was substantial inter-individual variation regarding the relative right-hand advantage for fluent circle drawing. All subjects underwent whole-brain diffusion tensor imaging...

  13. Effect of Different Thermomechanical Processes on the Microstructure, Texture, and Mechanical Properties of API 5L X70 Steel

    Science.gov (United States)

    Masoumi, Mohammad; Echeverri, Edwan Anderson Ariza; Silva, Cleiton Carvalho; Béreš, Miloslav; de Abreu, Hamilton Ferreira Gomes

    2018-03-01

    A commercial API 5L X70 steel plate was subjected to different thermomechanical processes to propose a novel thermomechanical rolling path to achieve improved mechanical properties. Scanning electron microscopy, electron backscatter diffraction, and x-ray texture analysis were employed for microstructural characterization. The results showed that strain-free recrystallized {001} ferrite grains that developed at higher rolling temperature could not meet the American Petroleum Institute (API) requirements. Also, refined and work-hardened grains that have formed in the intercritical region with high stored energy do not provide suitable tensile properties. However, fine martensite-austenite constituents dispersed in ferrite matrix with grains having predominantly {111} and {110} orientations parallel to the normal direction that developed under isothermal rolling at 850 °C provided an outstanding combination of tensile strength and ductility.

  14. Microstructural asymmetry of the corticospinal tracts predicts right-left differences in circle drawing skill in right-handed adolescents.

    Science.gov (United States)

    Angstmann, Steffen; Madsen, Kathrine Skak; Skimminge, Arnold; Jernigan, Terry L; Baaré, William F C; Siebner, Hartwig Roman

    2016-12-01

    Most humans show a strong preference to use their right hand, but strong preference for the right hand does not necessarily imply a strong right-left asymmetry in manual proficiency (i.e., dexterity). Here we tested the hypothesis that intra-individual asymmetry of manual proficiency would be reflected in microstructural differences between the right and left corticospinal tract (CST) in a cohort of 52 right-handed typically-developing adolescents (11-16 years). Participants were asked to fluently draw superimposed circles with their right dominant and left non-dominant hand. Temporal regularity of circle drawing movements was assessed for each hand using a digitizing tablet. Although all participants were right-handed, there was substantial inter-individual variation regarding the relative right-hand advantage for fluent circle drawing. All subjects underwent whole-brain diffusion tensor imaging at 3 Tesla. The right and left CST were defined as regions-of-interest and mean fractional anisotropy (FA) and diffusivity values were calculated for right and left CST. On average, mean FA values were higher in the left CST relative to right CST. The degree of right-left FA asymmetry showed a linear relationship with right-left asymmetry in fluent circle drawing after correction for age and gender. The higher the mean FA values were in the left dominant CST relative to the right non-dominant CST, the stronger was the relative right-hand advantage for regular circle drawing. These findings show that right-left differences in manual proficiency are highly variable in right-handed adolescents and that this variation is associated with a right-left microstructural asymmetry of the CST.

  15. Significance analysis of the regional differences on icing time of water onto fire protective clothing

    Science.gov (United States)

    Zhao, L. Z.; Jing, L. S.; Zhang, X. Z.; Xia, J. J.; Chen, Y.; Chen, T.; Hu, C.; Bao, Z. M.; Fu, X. C.; Wang, R. J.; Wang, Y.; Wang, Y. J.

    2017-09-01

    The object of this work was to determine the icing temperature in icing experiment. Firstly, a questionnaire investigation was carried out on 38 fire detachments in different regions. These Statistical percentage results were divided into northern east group and northern west group. Secondly, a significance analysis between these two results was made using Mann-Whitney U test. Then the icing temperature was determined in different regions. Thirdly, the icing experiment was made in the environment of -20°C in Daxing’an Mountain. The anti-icing effect of new fire protective clothing was verified in this icing.

  16. THE IMPORTANCE OF ‘SIGNIFICANT OTHERS’ IN BRIDGING THE GAPS BETWEEN DIFFERENT READING CONTEXTS

    Directory of Open Access Journals (Sweden)

    Anna-Karin Svensson

    2018-04-01

    Full Text Available The current research is an in-depth study of four pre-service teachers’ own experience of reading in various contexts and for different reasons. The aim is to analyse what has been significant regarding reading in a life history perspective by the use of narratives. A socio-cultural perspective on reading is used as analysis tool. The over-arching result from analysing pre-service teachers’ narratives is that reading is a relational process regardless of the context reading takes place in. The emerging themes allow a deeper understanding on critical aspects for developing reading in various contexts and at different levels. Significant others seem important in every reading practice, from new readers in primary school to pre-service teachers’ reading at university level. The narratives reveal a need for bridging the gaps that arise between the reading practices in the various contexts that students meet in school and university.

  17. Significant differences in physicochemical properties of human immunoglobulin kappa and lambda CDR3 regions

    Directory of Open Access Journals (Sweden)

    Catherine L Townsend

    2016-09-01

    Full Text Available Antibody variable regions are composed of a heavy and a light chain and in humans there are two light chain isotypes: kappa and lambda. Despite their importance in receptor editing, the light chain is often overlooked in the antibody literature, with the focus being on the heavy chain CDR-H3 region. In this paper, we set out to investigate the physicochemical and structural differences between human kappa and lambda light chain CDR regions. We constructed a dataset containing over 29,000 - light chain variable region sequences from IgM-transcribing, newly formed B cells isolated from human bone marrow and peripheral blood. We also used a published human naïve dataset to investigate the CDR-H3 properties of heavy chains paired with kappa and lambda light chains, and probed the Protein Data Bank (PDB to investigate the structural differences between kappa and lambda antibody CDR regions. We found that kappa and lambda light chains have very different CDR physicochemical and structural properties, whereas the heavy chains with which they are paired do not differ significantly. We also observed that the mean CDR3 N nucleotide addition in the kappa, lambda and heavy chain gene rearrangements are correlated within donors, but can differ between donors. This indicates that TdT may work with differing efficiencies between different people, but the same efficiency in the different classes of immunoglobulin chain within one person. We have observed large differences in the physicochemical and structural properties of kappa and lambda light chain CDR regions. This may reflect different roles in the humoral immune response.

  18. Significant Differences in Physicochemical Properties of Human Immunoglobulin Kappa and Lambda CDR3 Regions.

    Science.gov (United States)

    Townsend, Catherine L; Laffy, Julie M J; Wu, Yu-Chang Bryan; Silva O'Hare, Joselli; Martin, Victoria; Kipling, David; Fraternali, Franca; Dunn-Walters, Deborah K

    2016-01-01

    Antibody variable regions are composed of a heavy and a light chain, and in humans, there are two light chain isotypes: kappa and lambda. Despite their importance in receptor editing, the light chain is often overlooked in the antibody literature, with the focus being on the heavy chain complementarity-determining region (CDR)-H3 region. In this paper, we set out to investigate the physicochemical and structural differences between human kappa and lambda light chain CDR regions. We constructed a dataset containing over 29,000 light chain variable region sequences from IgM-transcribing, newly formed B cells isolated from human bone marrow and peripheral blood. We also used a published human naïve dataset to investigate the CDR-H3 properties of heavy chains paired with kappa and lambda light chains and probed the Protein Data Bank to investigate the structural differences between kappa and lambda antibody CDR regions. We found that kappa and lambda light chains have very different CDR physicochemical and structural properties, whereas the heavy chains with which they are paired do not differ significantly. We also observed that the mean CDR3 N nucleotide addition in the kappa, lambda, and heavy chain gene rearrangements are correlated within donors but can differ between donors. This indicates that terminal deoxynucleotidyl transferase may work with differing efficiencies between different people but the same efficiency in the different classes of immunoglobulin chain within one person. We have observed large differences in the physicochemical and structural properties of kappa and lambda light chain CDR regions. This may reflect different roles in the humoral immune response.

  19. Magnetic resonance imaging detects significant sex differences in human myocardial strain

    Directory of Open Access Journals (Sweden)

    Reynolds Lina M

    2011-08-01

    Full Text Available Abstract Background The pathophysiology responsible for the significant outcome disparities between men and women with cardiac disease is largely unknown. Further investigation into basic cardiac physiological differences between the sexes is needed. This study utilized magnetic resonance imaging (MRI-based multiparametric strain analysis to search for sex-based differences in regional myocardial contractile function. Methods End-systolic strain (circumferential, longitudinal, and radial was interpolated from MRI-based radiofrequency tissue tagging grid point displacements in each of 60 normal adult volunteers (32 females. Results The average global left ventricular (LV strain among normal female volunteers (n = 32 was significantly larger in absolute value (functionally better than in normal male volunteers (n = 28 in both the circumferential direction (Male/Female = -0.19 ± 0.02 vs. -0.21 ± 0.02; p = 0.025 and longitudinal direction (Male/Female = -0.14 ± 0.03 vs. -0.16 ± 0.02; p = 0.007. Conclusions The finding of significantly larger circumferential and longitudinal LV strain among normal female volunteers suggests that baseline contractile differences between the sexes may contribute to the well-recognized divergence in cardiovascular disease outcomes. Further work is needed in order to determine the pathologic changes that occur in LV strain between women and men with the onset of cardiovascular disease.

  20. Significant interarm blood pressure difference predicts cardiovascular risk in hypertensive patients: CoCoNet study.

    Science.gov (United States)

    Kim, Su-A; Kim, Jang Young; Park, Jeong Bae

    2016-06-01

    There has been a rising interest in interarm blood pressure difference (IAD), due to its relationship with peripheral arterial disease and its possible relationship with cardiovascular disease. This study aimed to characterize hypertensive patients with a significant IAD in relation to cardiovascular risk. A total of 3699 patients (mean age, 61 ± 11 years) were prospectively enrolled in the study. Blood pressure (BP) was measured simultaneously in both arms 3 times using an automated cuff-oscillometric device. IAD was defined as the absolute difference in averaged BPs between the left and right arm, and an IAD ≥ 10 mm Hg was considered to be significant. The Framingham risk score was used to calculate the 10-year cardiovascular risk. The mean systolic IAD (sIAD) was 4.3 ± 4.1 mm Hg, and 285 (7.7%) patients showed significant sIAD. Patients with significant sIAD showed larger body mass index (P < 0.001), greater systolic BP (P = 0.050), more coronary artery disease (relative risk = 1.356, P = 0.034), and more cerebrovascular disease (relative risk = 1.521, P = 0.072). The mean 10-year cardiovascular risk was 9.3 ± 7.7%. By multiple regression, sIAD was significantly but weakly correlated with the 10-year cardiovascular risk (β = 0.135, P = 0.008). Patients with significant sIAD showed a higher prevalence of coronary artery disease, as well as an increase in 10-year cardiovascular risk. Therefore, accurate measurements of sIAD may serve as a simple and cost-effective tool for predicting cardiovascular risk in clinical settings.

  1. Significant interarm blood pressure difference predicts cardiovascular risk in hypertensive patients

    Science.gov (United States)

    Kim, Su-A; Kim, Jang Young; Park, Jeong Bae

    2016-01-01

    Abstract There has been a rising interest in interarm blood pressure difference (IAD), due to its relationship with peripheral arterial disease and its possible relationship with cardiovascular disease. This study aimed to characterize hypertensive patients with a significant IAD in relation to cardiovascular risk. A total of 3699 patients (mean age, 61 ± 11 years) were prospectively enrolled in the study. Blood pressure (BP) was measured simultaneously in both arms 3 times using an automated cuff-oscillometric device. IAD was defined as the absolute difference in averaged BPs between the left and right arm, and an IAD ≥ 10 mm Hg was considered to be significant. The Framingham risk score was used to calculate the 10-year cardiovascular risk. The mean systolic IAD (sIAD) was 4.3 ± 4.1 mm Hg, and 285 (7.7%) patients showed significant sIAD. Patients with significant sIAD showed larger body mass index (P < 0.001), greater systolic BP (P = 0.050), more coronary artery disease (relative risk = 1.356, P = 0.034), and more cerebrovascular disease (relative risk = 1.521, P = 0.072). The mean 10-year cardiovascular risk was 9.3 ± 7.7%. By multiple regression, sIAD was significantly but weakly correlated with the 10-year cardiovascular risk (β = 0.135, P = 0.008). Patients with significant sIAD showed a higher prevalence of coronary artery disease, as well as an increase in 10-year cardiovascular risk. Therefore, accurate measurements of sIAD may serve as a simple and cost-effective tool for predicting cardiovascular risk in clinical settings. PMID:27310982

  2. Age-related changes in vertebral and iliac crest 3D bone microstructure-differences and similarities

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Jensen, Michael Vinkel; Niklassen, Andreas Steenholt

    2015-01-01

    Summary Age-related changes of vertebra and iliac crest 3D microstructure were investigated, and we showed that they were in general similar. The 95th percentile of vertebral trabecular thickness distribution increased with age for women. Surprisingly, vertebral and iliac crest bone microstructure...... was only weakly correlated (r = 0.38 to 0.75), despite the overall similar age-related changes.Introduction The purposes of the study were to determine the age-related changes in iliac and vertebral bone microstructure for women and men over a large age range and to investigate the relationship between...... the bone microstructure at these skeletal sites.Methods Matched sets of transiliac crest bone biopsies and lumbar vertebral body (L2) specimens from 41 women (19–96 years) and 39 men (23–95 years) were micro-computed tomography (μCT) scanned, and the 3D microstructure was quantified.Results For both women...

  3. Study creep in 4340 steels with different microstructure and plasma carbon nitridation processing; Estudo de fluencia em acos 4340 com diferentes microestruturas e tratamento de carbonitretacao a plasma

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla, A.J., E-mail: abdalla@ieav.cta.b [Departamento de Ciencia e Tecnologia Aeroespacial (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados; Carrer, I.R.; Barboza, M.J.R.; Baggio-Scheid, V.H. [Universidade de Sao Paulo (EEL/USP), Lorena, SP (Brazil). Escola de Engenharia; Moura Neto, C.; Reis, D.A.P. [Departamento de Ciencia e Tecnologia Aeroespacial (ITA/DCTA), Sao Jose dos Campos, SP (Brazil). Inst. Tecnologico de Aeronautica

    2010-07-01

    From the AISI 4340 bars specimens were made-for-test of creep, they were subjected to different heat treatments for the formation of multiphase microstructures. After this initial treatment, a lot of the specimens were tested in creep. One second batch of specimens was treated with a plasma carbonitriding, and later, were also tested. The carbonitriding layer and microstructure were characterized with X-ray analysis, laser confocal microscopy and hardness testing. Tests showed that the hardness in the steel was reduced due to thermochemical treatment at 500 deg C. We observed variation in creep behavior due to different microstructures formed. After the plasma treatment, there was a considerable reduction in the rate of creep and an increase in the time required for fracture. (author)

  4. Microstructural changes in NiFe{sub 2}O{sub 4} ceramics prepared with powders derived from different fuels in sol-gel auto-combustion technique

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, Lalita, E-mail: chauhan.lalita5@gmail.com; Sreenivas, K. [Department of Physics & Astrophysics, University of Delhi, Delhi-110007 (India); Bokolia, Renuka

    2016-05-23

    Structural properties of Nickel ferrite (NiFe{sub 2}O{sub 4}) ceramics prepared from powders derived from sol gel auto-combustion method using different fuels (citric acid, glycine and Dl-alanine) are compared. Changes in the structural properties at different sintering temperatures are investigated. X-ray diffraction (XRD) confirms the formation of single phase material with cubic structure. Ceramics prepared using the different powders obtained from different fuels show that that there are no significant changes in lattice parameters. However increasing sintering temperatures show significant improvement in density and grain size. The DL-alanine fuel is found to be the most effective fuel for producing NIFe{sub 2}O{sub 4} powders by the sol-gel auto combustion method and yields highly crystalline powders in the as-burnt stage itself at a low temperature (80 °C). Subsequent use of the powders in ceramic manufacturing produces dense NiFe{sub 2}O{sub 4} ceramics with a uniform microstructure and a large grain size.

  5. Microstructural changes in NiFe_2O_4 ceramics prepared with powders derived from different fuels in sol-gel auto-combustion technique

    International Nuclear Information System (INIS)

    Chauhan, Lalita; Sreenivas, K.; Bokolia, Renuka

    2016-01-01

    Structural properties of Nickel ferrite (NiFe_2O_4) ceramics prepared from powders derived from sol gel auto-combustion method using different fuels (citric acid, glycine and Dl-alanine) are compared. Changes in the structural properties at different sintering temperatures are investigated. X-ray diffraction (XRD) confirms the formation of single phase material with cubic structure. Ceramics prepared using the different powders obtained from different fuels show that that there are no significant changes in lattice parameters. However increasing sintering temperatures show significant improvement in density and grain size. The DL-alanine fuel is found to be the most effective fuel for producing NIFe_2O_4 powders by the sol-gel auto combustion method and yields highly crystalline powders in the as-burnt stage itself at a low temperature (80 °C). Subsequent use of the powders in ceramic manufacturing produces dense NiFe_2O_4 ceramics with a uniform microstructure and a large grain size.

  6. Microstructural changes in NiFe2O4 ceramics prepared with powders derived from different fuels in sol-gel auto-combustion technique

    Science.gov (United States)

    Chauhan, Lalita; Bokolia, Renuka; Sreenivas, K.

    2016-05-01

    Structural properties of Nickel ferrite (NiFe2O4) ceramics prepared from powders derived from sol gel auto-combustion method using different fuels (citric acid, glycine and Dl-alanine) are compared. Changes in the structural properties at different sintering temperatures are investigated. X-ray diffraction (XRD) confirms the formation of single phase material with cubic structure. Ceramics prepared using the different powders obtained from different fuels show that that there are no significant changes in lattice parameters. However increasing sintering temperatures show significant improvement in density and grain size. The DL-alanine fuel is found to be the most effective fuel for producing NIFe2O4 powders by the sol-gel auto combustion method and yields highly crystalline powders in the as-burnt stage itself at a low temperature (80 °C). Subsequent use of the powders in ceramic manufacturing produces dense NiFe2O4 ceramics with a uniform microstructure and a large grain size.

  7. Relationship between carbon microstructure, adsorption energy and hydrogen adsorption capacity at different temperatures

    International Nuclear Information System (INIS)

    Jacek Jagiello; Matthias Thommes

    2005-01-01

    Various microporous materials such as activated carbons, nano-tubes, synthetic microporous carbons as well as metal organic framework materials are being considered for hydrogen storage applications by means of physical adsorption. To develop materials of practical significance for hydrogen storage it is important to understand the relationships between pore sizes, adsorption energies and adsorption capacities. The pore size distribution (PSD) characterization is traditionally obtained from the analysis of nitrogen adsorption isotherms measured at 77 K. However, a portion of the pores accessible to H 2 may not be accessible to N 2 at this temperature. Therefore, it was recently proposed to use the DFT analysis of H 2 adsorption isotherms to characterize pore structure of materials considered for hydrogen storage applications. In present work, adsorption isotherms of H 2 and N 2 at cryogenic temperatures are used for the characterization of carbon materials. Adsorption measurements were performed with Autosorb 1 MP (Quantachrome Instruments, Boynton Beach, Florida, USA). As an example, Fig 1 compares PSDs calculated for the activated carbon sample (F400, Calgon Carbon) using combined H 2 and N 2 data, and using N 2 isotherm only. The nitrogen derived PSD does not include certain amount of micropores which are accessible to H 2 but not to N 2 molecules. Obviously, the difference in the calculated PSDs by the two methods will depend on the actual content of small micropores in a given sample. Carbon adsorption properties can also be characterized by the isosteric heat of adsorption, Qst, related to the adsorption energy and dependent on the carbon pore/surface structure. Fig 2 shows Qst data calculated using the Clausius-Clapeyron equation from H 2 isotherms measured at 77 K and 87 K for the carbon molecular sieve CMS 5A (Takeda), oxidized single wall nano-tubes (SWNT), and graphitized carbon black (Supelco). The Qst values decrease with increasing pore sizes. The

  8. Using the Bootstrap Method for a Statistical Significance Test of Differences between Summary Histograms

    Science.gov (United States)

    Xu, Kuan-Man

    2006-01-01

    A new method is proposed to compare statistical differences between summary histograms, which are the histograms summed over a large ensemble of individual histograms. It consists of choosing a distance statistic for measuring the difference between summary histograms and using a bootstrap procedure to calculate the statistical significance level. Bootstrapping is an approach to statistical inference that makes few assumptions about the underlying probability distribution that describes the data. Three distance statistics are compared in this study. They are the Euclidean distance, the Jeffries-Matusita distance and the Kuiper distance. The data used in testing the bootstrap method are satellite measurements of cloud systems called cloud objects. Each cloud object is defined as a contiguous region/patch composed of individual footprints or fields of view. A histogram of measured values over footprints is generated for each parameter of each cloud object and then summary histograms are accumulated over all individual histograms in a given cloud-object size category. The results of statistical hypothesis tests using all three distances as test statistics are generally similar, indicating the validity of the proposed method. The Euclidean distance is determined to be most suitable after comparing the statistical tests of several parameters with distinct probability distributions among three cloud-object size categories. Impacts on the statistical significance levels resulting from differences in the total lengths of satellite footprint data between two size categories are also discussed.

  9. Two distinct groups within the Bacillus subtilis group display significantly different spore heat resistance properties.

    Science.gov (United States)

    Berendsen, Erwin M; Zwietering, Marcel H; Kuipers, Oscar P; Wells-Bennik, Marjon H J

    2015-02-01

    The survival of bacterial spores after heat treatment and the subsequent germination and outgrowth in a food product can lead to spoilage of the food product and economical losses. Prediction of time-temperature conditions that lead to sufficient inactivation requires access to detailed spore thermal inactivation kinetics of relevant model strains. In this study, the thermal inactivation kinetics of spores of fourteen strains belonging to the Bacillus subtilis group were determined in detail, using both batch heating in capillary tubes and continuous flow heating in a micro heater. The inactivation data were fitted using a log linear model. Based on the spore heat resistance data, two distinct groups (p subtilis group could be identified. One group of strains had spores with an average D120 °C of 0.33 s, while the spores of the other group displayed significantly higher heat resistances, with an average D120 °C of 45.7 s. When comparing spore inactivation data obtained using batch- and continuous flow heating, the z-values were significantly different, hence extrapolation from one system to the other was not justified. This study clearly shows that heat resistances of spores from different strains in the B. subtilis group can vary greatly. Strains can be separated into two groups, to which different spore heat inactivation kinetics apply. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Significant clinical differences in primary hyperparathyroidism between patients with and those without concomitant thyroid disease

    International Nuclear Information System (INIS)

    Masatsugu, Toshihiro; Kuroki, Syoji; Tanaka, Masao

    2005-01-01

    We evaluated the differences in diagnosis and treatment for primary hyperparathyroidism (pHPT) in patients with and those without concomitant thyroid disease. One hundred and ten patients with pHPT underwent parathyroid localization and thyroid examination by ultrasonography (US) and sestamibi scintigraphy (MIBI). The clinical and biochemical findings, parathyroid localization, and operations performed were compared in 49 patients without thyroid disease and 61 patients with thyroid disease. Asymptomatic hypercalcemia was significantly more prevalent in patients with concomitant thyroid disease (88.5%) than in those without thyroid disease (49.0%) (P<0.01). The mean serum calcium was significantly higher and the inorganic phosphate level was significantly lower in patients without concomitant thyroid disease than in those with concomitant thyroid disease (P<0.05, P<0.01, respectively). The pathologic parathyroid gland was identified significantly more often in patients without concomitant thyroid disease than in those with concomitant thyroid disease both by US and MIBI (P<0.05). Unilateral exploration was performed more often in patients without thyroid disease than in those with thyroid disease (P<0.01). Primary hyperparathyroidism was diagnosed at an earlier stage in patients with concomitant thyroid disease. Thyroid disease concomitant with pHPT influenced parathyroid localization as well as the indication for minimally invasive parathyroidectomy. (author)

  11. Small airway function changes and its clinical significance of asthma patients in different clinical phases

    Directory of Open Access Journals (Sweden)

    Yan-Hui Zhou

    2016-11-01

    Full Text Available Objective: To observe the small airways function changes of asthmatic patients in different clinical phases and to discuss its clinical significance. Methods: A total of 127 patients diagnosed as asthma were selected randomly and pulmonary function (PF of them was determined by conventional method. Then they were divided into A, B and C group based on PF results. All 34 patients in A group suffered from acute asthma attack for the first time. All 93 patients in B group had been diagnosed as asthma but in remission phase. C Group was regarded as Control group with 20 healthy volunteers. Then FEV1, FEF50%, FEF75% levels of patients in each group were analyzed, and ΔFEV1, ΔFEF75% and ΔFEF50% levels of patients in each group were compared after bronchial dilation test. Results: It was found that most patients in group A and B had abnormal small airways function, and their small airways function was significantly different compared with that of group C (P<0.01. In addition, except for group C, ΔFEF75%,ΔFEF50% levels in A and B group were improved more significantly than ΔFEV1 levels (P<0.01. Conclusions: Asthma patients in acute phase all have abnormal small airways function. Most asthma patients in remission phase also have abnormal small airways function. After bronchial dilation test, whether patients in acute phase or in remission phase, major and small airways function of them are improved, but improvement of small airways function is weaker than that of major airways. This indicates that asthma respiratory tract symptoms in different phases exists all the time and so therapeutic process is needed to perform step by step.

  12. Increased frequency of retinopathy of prematurity over the last decade and significant regional differences.

    Science.gov (United States)

    Holmström, Gerd; Tornqvist, Kristina; Al-Hawasi, Abbas; Nilsson, Åsa; Wallin, Agneta; Hellström, Ann

    2018-03-01

    Retinopathy of prematurity (ROP) causes childhood blindness globally in prematurely born infants. Although increased levels of oxygen supply lead to increased survival and reduced frequency of cerebral palsy, increased incidence of ROP is reported. With the help of a Swedish register for ROP, SWEDROP, national and regional incidences of ROP and frequencies of treatment were evaluated from 2008 to 2015 (n = 5734), as well as before and after targets of provided oxygen changed from 85-89% to 91-95% in 2014. Retinopathy of prematurity (ROP) was found in 31.9% (1829/5734) of all infants with a gestational age (GA) of <31 weeks at birth and 5.7% of the infants (329/5734) had been treated for ROP. Analyses of the national data revealed an increased incidence of ROP during the 8-year study period (p = 0.003), but there was no significant increase in the frequency of treatment. There were significant differences between the seven health regions of Sweden, regarding both incidence of ROP and frequency of treatment (p < 0.001). Comparison of regional data before and after the new oxygen targets revealed a significant increase in treated ROP in one region [OR: 2.24 (CI: 1.11-4.49), p = 0.024] and a borderline increase in one other [OR: 3.08 (CI: 0.99-9.60), p = 0.052]. The Swedish national ROP register revealed an increased incidence of ROP during an 8-year period and significant regional differences regarding the incidence of ROP and frequency of treatment. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  13. Factors correlating with significant differences between X-ray structures of myoglobin

    International Nuclear Information System (INIS)

    Rashin, Alexander A.; Domagalski, Marcin J.; Zimmermann, Michael T.; Minor, Wladek; Chruszcz, Maksymilian; Jernigan, Robert L.

    2014-01-01

    Conformational differences between myoglobin structures are studied. Most structural differences in whale myoglobin beyond the uncertainty threshold can be correlated with a few specific structural factors. There are always exceptions and a search for additional factors is needed. The results might have serious implications for biological insights from conformational differences. Validation of general ideas about the origins of conformational differences in proteins is critical in order to arrive at meaningful functional insights. Here, principal component analysis (PCA) and distance difference matrices are used to validate some such ideas about the conformational differences between 291 myoglobin structures from sperm whale, horse and pig. Almost all of the horse and pig structures form compact PCA clusters with only minor coordinate differences and outliers that are easily explained. The 222 whale structures form a few dense clusters with multiple outliers. A few whale outliers with a prominent distortion of the GH loop are very similar to the cluster of horse structures, which all have a similar GH-loop distortion apparently owing to intermolecular crystal lattice hydrogen bonds to the GH loop from residues near the distal histidine His64. The variations of the GH-loop coordinates in the whale structures are likely to be owing to the observed alternative intermolecular crystal lattice bond, with the change to the GH loop distorting bonds correlated with the binding of specific ‘unusual’ ligands. Such an alternative intermolecular bond is not observed in horse myoglobins, obliterating any correlation with the ligands. Intermolecular bonds do not usually cause significant coordinate differences and cannot be validated as their universal cause. Most of the native-like whale myoglobin structure outliers can be correlated with a few specific factors. However, these factors do not always lead to coordinate differences beyond the previously determined uncertainty

  14. Factors correlating with significant differences between X-ray structures of myoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Rashin, Alexander A., E-mail: alexander-rashin@hotmail.com [BioChemComp Inc., 543 Sagamore Avenue, Teaneck, NJ 07666 (United States); Iowa State University, 112 Office and Lab Bldg, Ames, IA 50011-3020 (United States); Domagalski, Marcin J. [University of Virginia, 1340 Jefferson Park Avenue, Jordan Hall, Room 4223, Charlottesville, VA 22908 (United States); Zimmermann, Michael T. [Iowa State University, 112 Office and Lab Bldg, Ames, IA 50011-3020 (United States); Minor, Wladek [University of Virginia, 1340 Jefferson Park Avenue, Jordan Hall, Room 4223, Charlottesville, VA 22908 (United States); Chruszcz, Maksymilian [University of Virginia, 1340 Jefferson Park Avenue, Jordan Hall, Room 4223, Charlottesville, VA 22908 (United States); University of South Carolina, 631 Sumter Street, Columbia, SC 29208 (United States); Jernigan, Robert L. [Iowa State University, 112 Office and Lab Bldg, Ames, IA 50011-3020 (United States); BioChemComp Inc., 543 Sagamore Avenue, Teaneck, NJ 07666 (United States)

    2014-02-01

    Conformational differences between myoglobin structures are studied. Most structural differences in whale myoglobin beyond the uncertainty threshold can be correlated with a few specific structural factors. There are always exceptions and a search for additional factors is needed. The results might have serious implications for biological insights from conformational differences. Validation of general ideas about the origins of conformational differences in proteins is critical in order to arrive at meaningful functional insights. Here, principal component analysis (PCA) and distance difference matrices are used to validate some such ideas about the conformational differences between 291 myoglobin structures from sperm whale, horse and pig. Almost all of the horse and pig structures form compact PCA clusters with only minor coordinate differences and outliers that are easily explained. The 222 whale structures form a few dense clusters with multiple outliers. A few whale outliers with a prominent distortion of the GH loop are very similar to the cluster of horse structures, which all have a similar GH-loop distortion apparently owing to intermolecular crystal lattice hydrogen bonds to the GH loop from residues near the distal histidine His64. The variations of the GH-loop coordinates in the whale structures are likely to be owing to the observed alternative intermolecular crystal lattice bond, with the change to the GH loop distorting bonds correlated with the binding of specific ‘unusual’ ligands. Such an alternative intermolecular bond is not observed in horse myoglobins, obliterating any correlation with the ligands. Intermolecular bonds do not usually cause significant coordinate differences and cannot be validated as their universal cause. Most of the native-like whale myoglobin structure outliers can be correlated with a few specific factors. However, these factors do not always lead to coordinate differences beyond the previously determined uncertainty

  15. Sex Differences in White Matter Microstructure in the Human Brain Predominantly Reflect Differences in Sex Hormone Exposure

    NARCIS (Netherlands)

    van Hemmen, J; Saris, I M J; Cohen-Kettenis, P T; Veltman, D J; Pouwels, P J W; Bakker, J

    Sex differences have been described regarding several aspects of human brain morphology; however, the exact biological mechanisms underlying these differences remain unclear in humans. Women with the complete androgen insensitivity syndrome (CAIS), who lack androgen action in the presence of a 46,XY

  16. Process of Judging Significant Modifications for Different Transportation Systems compared to the Approach for Nuclear Installations

    Directory of Open Access Journals (Sweden)

    Nicolas Petrek

    2015-12-01

    Full Text Available The implementation of the CSM regulation by the European Commission in 2009 which harmonizes the risk assessment process and introduces a rather new concept of judging changes within the European railway industry. This circumstance has risen the question how other technology sectors handle the aspect of modifications and alterations. The paper discusses the approaches for judging the significance of modifications within the three transport sectors of European railways, aviation and maritime transportation and the procedure which is used in the area of nuclear safety. We will outline the similarities and differences between these four methods and discuss the underlying reasons. Finally, we will take into account the role of the European legislator and the fundamental idea of a harmonization of the different approaches.

  17. Relationship between carbon microstructure, adsorption energy and hydrogen adsorption capacity at different temperatures

    International Nuclear Information System (INIS)

    Jagiello, J.; Thommes, M.

    2005-01-01

    Various microporous materials such as activated carbons, nano-tubes, synthetic micro-porous carbons as well as metal organic framework materials are being considered for hydrogen storage applications by means of physical adsorption. To develop materials of practical significance for hydrogen storage it is important to understand the relationships between pore sizes, adsorption energies and adsorption capacities. The pore size distribution (PSD) characterization is traditionally obtained from the analysis of nitrogen adsorption isotherms measured at 77 K. However, a portion of the pores accessible to H 2 may not be accessible to N 2 at this temperature. Therefore, it was recently proposed to use the DFT analysis of H 2 adsorption isotherms to characterize pore structure of materials considered for hydrogen storage applications [1]. In present work, adsorption isotherms of H 2 and N 2 at cryogenic temperatures are used for the characterization of carbon materials. Adsorption measurements were performed with Autosorb 1 MP [Quantachrome Instruments, Boynton Beach, Florida, USA]. As an example, Fig 1 compares PSDs calculated for the activated carbon sample (F400, Calgon Carbon) using combined H 2 and N 2 data, and using N 2 isotherm only. The nitrogen derived PSD does not include certain amount of micro-pores which are accessible to H 2 but not to N 2 molecules. Obviously, the difference in the calculated PSDs by the two methods will depend on the actual content of small micro-pores in a given sample. Carbon adsorption properties can also be characterized by the isosteric heat of adsorption, Qst, related to the adsorption energy and dependent on the carbon pore/surface structure. Fig 2 shows Qst data calculated using the Clausius-Clapeyron equation from H 2 isotherms measured at 77 K and 87 K for the carbon molecular sieve CMS 5A (Takeda), oxidized single wall nano-tubes (SWNT) [2], and graphitized carbon black (Supelco). The Qst values decrease with increasing pore

  18. Microstructural evolution and mechanical properties of differently heat-treated binder jet printed samples from gas- and water-atomized alloy 625 powders

    International Nuclear Information System (INIS)

    Mostafaei, Amir; Toman, Jakub; Stevens, Erica L.; Hughes, Eamonn T.; Krimer, Yuval L.; Chmielus, Markus

    2017-01-01

    In this study, we investigate the effect of powders resulting from different atomization methods on properties of binder jet printed and heat-treated samples. Air-melted gas atomized (GA) and water atomized (WA) nickel-based alloy 625 powders were used to binder jet print samples for a detailed comparative study on microstructural evolution and mechanical properties. GA printed samples achieved higher sintering density (99.2%) than WA samples (95.0%) due to differences in powder morphology and chemistry. Grain sizes of GA and WA samples at their highest density were 89 ± 21 μm and 88 ± 26 μm, respectively. Mechanical tests were conducted on optimally sintered samples and sintered plus aged samples; aging further improved microstructure and mechanical properties. This study shows that microstructural evolution (densification, and carbide, oxide and intermetallic phase formation) is very different for GA and WA binder jet printed and heat-treated samples. This difference in microstructural evolution results in different mechanical properties with the superior sintered and aged GA specimen reaching a hardness of 327 ± 7 HV_0_._1, yield strength of 394 ± 15 MPa, and ultimate tensile strength of 718 ± 14 MPa which are higher than cast alloy 625 values.

  19. DNA entropy reveals a significant difference in complexity between housekeeping and tissue specific gene promoters.

    Science.gov (United States)

    Thomas, David; Finan, Chris; Newport, Melanie J; Jones, Susan

    2015-10-01

    The complexity of DNA can be quantified using estimates of entropy. Variation in DNA complexity is expected between the promoters of genes with different transcriptional mechanisms; namely housekeeping (HK) and tissue specific (TS). The former are transcribed constitutively to maintain general cellular functions, and the latter are transcribed in restricted tissue and cells types for specific molecular events. It is known that promoter features in the human genome are related to tissue specificity, but this has been difficult to quantify on a genomic scale. If entropy effectively quantifies DNA complexity, calculating the entropies of HK and TS gene promoters as profiles may reveal significant differences. Entropy profiles were calculated for a total dataset of 12,003 human gene promoters and for 501 housekeeping (HK) and 587 tissue specific (TS) human gene promoters. The mean profiles show the TS promoters have a significantly lower entropy (pentropy distributions for the 3 datasets show that promoter entropies could be used to identify novel HK genes. Functional features comprise DNA sequence patterns that are non-random and hence they have lower entropies. The lower entropy of TS gene promoters can be explained by a higher density of positive and negative regulatory elements, required for genes with complex spatial and temporary expression. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Super-resolution structure of DNA significantly differs in buccal cells of controls and Alzheimer's patients.

    Science.gov (United States)

    Garcia, Angeles; Huang, David; Righolt, Amanda; Righolt, Christiaan; Kalaw, Maria Carmela; Mathur, Shubha; McAvoy, Elizabeth; Anderson, James; Luedke, Angela; Itorralba, Justine; Mai, Sabine

    2017-09-01

    The advent of super-resolution microscopy allowed for new insights into cellular and physiological processes of normal and diseased cells. In this study, we report for the first time on the super-resolved DNA structure of buccal cells from patients with Alzheimer's disease (AD) versus age- and gender-matched healthy, non-caregiver controls. In this super-resolution study cohort of 74 participants, buccal cells were collected and their spatial DNA organization in the nucleus examined by 3D Structured Illumination Microscopy (3D-SIM). Quantitation of the super-resolution DNA structure revealed that the nuclear super-resolution DNA structure of individuals with AD significantly differs from that of their controls (p structure of AD significantly differs in mild, moderate, and severe disease with respect to the DNA-containing and DNA-free/poor spaces. We conclude that whole genome remodeling is a feature of buccal cells in AD. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.

  1. Study of microstructure, texture and mechanical properties of Zr–2.5Nb alloy pressure tubes fabricated with different processing routes

    International Nuclear Information System (INIS)

    Saibaba, N.; Vaibhaw, Kumar; Neogy, S.; Mani Krishna, K.V.; Jha, S.K.; Phani Babu, C.; Ramana Rao, S.V.; Srivastava, D.; Dey, G.K.

    2013-01-01

    Different fabrication trials involving the variation in three important stages of Zr–2.5Nb pressure tube were undertaken. The variations were with respect to the mode of breaking the cast structure of the ingot (forging vs extrusion), the hot extrusion ratio and the number of subsequent cold work stages to produce the finished tube. It was observed that the forging process resulted in superior performance in breaking the cast structure. Higher extrusion ratios resulted in more favorable texture and microstructure. More continuity of the beta phase was observed in the final microstructure for the route involving the single cold work step subsequent to hot extrusion

  2. Subgroups of Paediatric Acute Lymphoblastic Leukaemia Might Differ Significantly in Genetic Predisposition to Asparaginase Hypersensitivity.

    Directory of Open Access Journals (Sweden)

    Nóra Kutszegi

    Full Text Available L-asparaginase (ASP is a key element in the treatment of paediatric acute lymphoblastic leukaemia (ALL. However, hypersensitivity reactions (HSRs to ASP are major challenges in paediatric patients. Our aim was to investigate genetic variants that may influence the risk to Escherichia coli-derived ASP hypersensitivity. Sample and clinical data collection was carried out from 576 paediatric ALL patients who were treated according to protocols from the Berlin-Frankfurt-Münster Study Group. A total of 20 single nucleotide polymorphisms (SNPs in GRIA1 and GALNT10 genes were genotyped. Patients with GRIA1 rs4958351 AA/AG genotype showed significantly reduced risk to ASP hypersensitivity compared to patients with GG genotype in the T-cell ALL subgroup (OR = 0.05 (0.01-0.26; p = 4.70E-04, while no such association was found in pre-B-cell ALL. In the medium risk group two SNPs of GRIA1 (rs2055083 and rs707176 were associated significantly with the occurrence of ASP hypersensitivity (OR = 0.21 (0.09-0.53; p = 8.48E-04 and OR = 3.02 (1.36-6.73; p = 6.76E-03, respectively. Evaluating the genders separately, however, the association of rs707176 with ASP HSRs was confined only to females. Our results suggest that genetic variants of GRIA1 might influence the risk to ASP hypersensitivity, but subgroups of patients can differ significantly in this respect.

  3. Microstructure and ultrastructure of alfalfa seeds with different moisture contents after satellite carrying

    International Nuclear Information System (INIS)

    Feng Peng; Li Jian; Zhang Yunwei; Liu Ruohan

    2009-01-01

    Seeds with different moisture contents (9%, 11%, 13%, 15%, 17%) of Medicago sativa L. cv. Zhongmu No. 1 were boarded on the Shijian-8 satellite and then the microscopic and ultrastructure were observed. The results showed that spongy tissue and leaf palisade of plant after space flight were different to their control. The impact of on spongy cells was more obvious than the palisade cells; greater chloroplasts, empty and crack overflow mitochondria were observed. More starch grain were found at the samples cultured from 15% and 17% moisture content treatment, which was analyzed that starch grains in leaf cell was affected by the moisture content of seeds. (authors)

  4. Power of Ultra Performance Liquid Chromatography/Electrospray Ionization-MS Reconstructed Ion Chromatograms in the Characterization of Small Differences in Polymer Microstructure.

    Science.gov (United States)

    Epping, Ruben; Panne, Ulrich; Falkenhagen, Jana

    2018-03-06

    From simple homopolymers to functionalized, 3-dimensional structured copolymers, the complexity of polymeric materials has become more and more sophisticated. With new applications, for instance, in the semiconductor or pharmaceutical industry, the requirements for the characterization have risen with the complexity of the used polymers. For each additional distribution, an additional dimension in analysis is needed. Small, often isomeric heterogeneities in topology or microstructure can usually not be simply separated chromatographically or distinguished by any common detector but affect the properties of materials significantly. For a drug delivery system, for example, the degree of branching and branching distribution is crucial for the formation of micelles. Instead of a complicated, time-consuming, and/or expensive 2D-chromatography or ion mobility spectrometry (IMS) method, that also has its limitations, in this work, a simple approach using size exclusion chromatography (SEC) coupled with electrospray ionization (ESI) mass spectrometry is proposed. The online coupling allows the analysis of reconstructed ion chromatograms (RICs) of each degree of polymerization. While a complete separation often cannot be achieved, the derived retention times and peak widths lead to information on the existence and dispersity of heterogeneities. Although some microstructural heterogeneities like short chain branching can for large polymers be characterized with methods such as light scattering, for oligomers where the heterogeneities just start to form and their influence is at the maximum, they are inaccessible with these methods. It is also shown that with a proper calibration even quantitative information can be obtained. This method is suitable to detect small differences in, e.g., branching, 3D-structure, monomer sequence, or tacticity and could potentially be used in routine analysis to quickly determine deviations.

  5. Intrapartum caesarean rates differ significantly between ethnic groups--relationship to induction.

    LENUS (Irish Health Repository)

    Ismail, Khadijah I

    2012-01-31

    OBJECTIVE: Given international variation in obstetric practices and outcomes, comparison of labour outcomes in different ethnic groups could provide important information regarding the underlying reasons for rising caesarean delivery rates. Increasing numbers of women from Eastern European countries are now delivering in Irish maternity hospitals. We compared labour outcomes between Irish and Eastern European (EE) women in a large tertiary referral center. STUDY DESIGN: This was a prospective consecutive cohort study encompassing a single calendar year. The cohort comprised 5550 Irish and 867 EE women delivered in a single institution in 2009. Women who had multiple pregnancies, breech presentation, and elective or pre-labour caesarean sections (CS) were excluded. Data obtained from birth registers included maternal age, nationality, parity, gestation, onset of labour, mode of delivery and birth weight. RESULTS: The overall intrapartum CS rate was 11.4% and was significantly higher in Irish compared to EE women (11.8% vs. 8.8%; p=0.008). The proportion of primiparas was lower in Irish compared to EE women (44.8% vs. 63.6%; p<0.0001). The intrapartum CS rate was almost doubled in Irish compared to EE primiparas (20.7% vs. 11.0%; p<0.0001). Analysis of primiparas according to labour onset revealed a higher intrapartum CS rate in Irish primiparas in both spontaneous (13.5% vs. 7.2%; p<0.0001) and induced labour (29.5% vs. 19.3%; p=0.005). Irish women were older with 19.7% of primiparas aged more than 35, compared to 1.6% of EE women (p<0.0001). The primigravid CS rate in Irish women was significantly higher in women aged 35 years or older compared women aged less than 35 (30.6% vs. 18.3%; p<0.0001) consistent in both spontaneous and induced labour. The primiparous induction rate was 45.4% in Irish women compared to 32% in EE women, and more Irish women were induced before 41 weeks gestation. CONCLUSION: The results highlight that primigravid intrapartum CS rates were

  6. Significant differences in parameters of glucose metabolism in children of hypertensive and normotensive parents.

    Science.gov (United States)

    Gryko, Anna; Głowińska-Olszewska, Barbara; Płudowska, Katarzyna; Smithson, W Henry; Owłasiuk, Anna; Żelazowska-Rutkowska, Beata; Wojtkielewicz, Katarzyna; Milewski, Robert; Chlabicz, Sławomir

    2017-01-01

    In the recent years, alterations in the carbohydrate metabolism, including insulin resistance, are considered as risk factors in the development of hypertension and its complications in young age. Hypertension is associated with significant cardiovascular morbidity and mortality. The onset of pathology responsible for the development of hypertension, as well as levels of biomarkers specific for early stages of atherosclerosis are poorly understood. To compare a group of children whose parents have a history of hypertension (study group) with a group of children with normotensive parents (reference group), with consideration of typical risk factors for atherosclerosis, parameters of lipid and carbohydrate metabolism, anthropometric data and new biomarkers of early cardiovascular disease (hsCRP, adiponectin, sICAM-1). The study population consists of 84 children. Of these, 40 children (mean age 13.6±2.7 years) had a parental history of hypertension, and 44 aged 13.1±3.7 yrs were children of normotensive parents. Anthropometric measurements were taken, and measurements of blood pressure, lipid profile, glucose and insulin levels were carried out. The insulin resistance index (HOMA IR) was calculated. Levels of hsCRP, soluble cell adhesion molecules (sICAM) and adiponectin were measured. There were no statistically significant differences in anthropometric parameters (body mass, SDS BMI, skin folds) between groups. Values of systolic blood pressure were statistically significantly higher in the study group (Me 108 vs. 100 mmHg, p= 0.031), as were glycaemia (Me 80 vs. 67 mg/dl pchildren of hypertensive parents) (Me 1.68 vs. 0.80 mmol/l × mU/l, p=0.007). Lower adiponectin levels (Me 13959.45 vs. 16822 ng/ml, p=0.020) were found in children with a family history of hypertension. No significant differences were found in the levels of sICAM, hsCRP, and parameters of lipid metabolism. Family history of hypertension is correlated with higher values of systolic blood

  7. Gender differences in binaural speech-evoked auditory brainstem response: are they clinically significant?

    Science.gov (United States)

    Jalaei, Bahram; Azmi, Mohd Hafiz Afifi Mohd; Zakaria, Mohd Normani

    2018-05-17

    Binaurally evoked auditory evoked potentials have good diagnostic values when testing subjects with central auditory deficits. The literature on speech-evoked auditory brainstem response evoked by binaural stimulation is in fact limited. Gender disparities in speech-evoked auditory brainstem response results have been consistently noted but the magnitude of gender difference has not been reported. The present study aimed to compare the magnitude of gender difference in speech-evoked auditory brainstem response results between monaural and binaural stimulations. A total of 34 healthy Asian adults aged 19-30 years participated in this comparative study. Eighteen of them were females (mean age=23.6±2.3 years) and the remaining sixteen were males (mean age=22.0±2.3 years). For each subject, speech-evoked auditory brainstem response was recorded with the synthesized syllable /da/ presented monaurally and binaurally. While latencies were not affected (p>0.05), the binaural stimulation produced statistically higher speech-evoked auditory brainstem response amplitudes than the monaural stimulation (p0.80), substantive gender differences were noted in most of speech-evoked auditory brainstem response peaks for both stimulation modes. The magnitude of gender difference between the two stimulation modes revealed some distinct patterns. Based on these clinically significant results, gender-specific normative data are highly recommended when using speech-evoked auditory brainstem response for clinical and future applications. The preliminary normative data provided in the present study can serve as the reference for future studies on this test among Asian adults. Copyright © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  8. Effect of different lay-ups on the microstructure, mechanical properties and neutron transmission of neutron shielding fibre metal laminates

    International Nuclear Information System (INIS)

    Fu, Xuelong; Tang, Xiaobin; Hu, Yubing; Li, Huaguan; Tao, Jie

    2016-01-01

    A novel neutron shielding fibre metal laminates (NSFMLs) with different lay-ups, composed of stacking layers of AA6061 plates, neutron shielding composite and carbon fibre reinforced polyimide (CFRP), were fabricated using hot molding process in atmospheric environments. The microstructure, mechanical properties and neutron transmission of the NSFMLs were evaluated, respectively. The results indicated that the NSFMLs possessed good mechanical properties owing to the good interfacial adhesion of the components. Tensile strength and elastic modulus of the NSFMLs increased with the numbers of lay-ups, while the elongation to fracture exhibited obvious declining tendency. Flexural strength and modulus of the NSFMLs were improved obviously with the increasing of stacking layers. Neutron transmission of the NSFMLs decreased obviously with increasing the number of lay-ups, owing to the increase of "1"0B areal density. Besides, the effect of carbon fibres on the neutron shielding performance of the NSFMLs was also taken into consideration. - Highlights: • A novel neutron shielding fibre metal laminates (NSFMLs) with different lay-ups was successfully fabricated using hot molding process. • Mechanical properties of the NSFMLs were performed in accordance with relative standards. • Neutron transmission of the NSFMLs was conducted according to the testing results. • The effect of carbon fibres on the neutron transmission of the NSFMLs was also investigated.

  9. Effect of different lay-ups on the microstructure, mechanical properties and neutron transmission of neutron shielding fibre metal laminates

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Xuelong [College of Material Science & Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 211100 (China); Department of Mechanical and Electronic Engineering, Jiangsu Polytechnic of Finance & Economics, Huai' an, 223003 (China); Tang, Xiaobin; Hu, Yubing; Li, Huaguan [College of Material Science & Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 211100 (China); Tao, Jie, E-mail: taojie@nuaa.edu.cn [College of Material Science & Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 211100 (China)

    2016-07-15

    A novel neutron shielding fibre metal laminates (NSFMLs) with different lay-ups, composed of stacking layers of AA6061 plates, neutron shielding composite and carbon fibre reinforced polyimide (CFRP), were fabricated using hot molding process in atmospheric environments. The microstructure, mechanical properties and neutron transmission of the NSFMLs were evaluated, respectively. The results indicated that the NSFMLs possessed good mechanical properties owing to the good interfacial adhesion of the components. Tensile strength and elastic modulus of the NSFMLs increased with the numbers of lay-ups, while the elongation to fracture exhibited obvious declining tendency. Flexural strength and modulus of the NSFMLs were improved obviously with the increasing of stacking layers. Neutron transmission of the NSFMLs decreased obviously with increasing the number of lay-ups, owing to the increase of {sup 10}B areal density. Besides, the effect of carbon fibres on the neutron shielding performance of the NSFMLs was also taken into consideration. - Highlights: • A novel neutron shielding fibre metal laminates (NSFMLs) with different lay-ups was successfully fabricated using hot molding process. • Mechanical properties of the NSFMLs were performed in accordance with relative standards. • Neutron transmission of the NSFMLs was conducted according to the testing results. • The effect of carbon fibres on the neutron transmission of the NSFMLs was also investigated.

  10. Relation between Microstructure and Charge Transport in Polymers of Different Regioregularity

    KAUST Repository

    McMahon, David P.; Cheung, David L.; Goris, Ludwig; Dacuña, Javier; Salleo, Alberto; Troisi, Alessandro

    2011-01-01

    A methodology to link an atomistic description of a polymeric semiconductor with the experimental electrical characteristics of real devices is proposed. Microscopic models of poly(3-hexylthiophene) (P3HT) of different regioregularity are generated using molecular dynamics and their electronic structure determined via an approximate quantum chemistry scheme. The resulting density of trap states and distribution of localized and delocalized states is then compared with that obtained from thin film transistor measurements of P3HT at different regioregularities. The two complementary methodologies provide a converging description of the electron transport in semicrystalline P3HT and the role of regioregularity. States at the valence band edge are localized, but delocalized "band-like" states are thermally accessible and quantitatively characterized. Both theory and experiment agree that contrary to a commonly held belief the trap density and the DOS shape are little affected by the presence of regioregularity defects. © 2011 American Chemical Society.

  11. Relation between Microstructure and Charge Transport in Polymers of Different Regioregularity

    KAUST Repository

    McMahon, David P.

    2011-10-06

    A methodology to link an atomistic description of a polymeric semiconductor with the experimental electrical characteristics of real devices is proposed. Microscopic models of poly(3-hexylthiophene) (P3HT) of different regioregularity are generated using molecular dynamics and their electronic structure determined via an approximate quantum chemistry scheme. The resulting density of trap states and distribution of localized and delocalized states is then compared with that obtained from thin film transistor measurements of P3HT at different regioregularities. The two complementary methodologies provide a converging description of the electron transport in semicrystalline P3HT and the role of regioregularity. States at the valence band edge are localized, but delocalized "band-like" states are thermally accessible and quantitatively characterized. Both theory and experiment agree that contrary to a commonly held belief the trap density and the DOS shape are little affected by the presence of regioregularity defects. © 2011 American Chemical Society.

  12. Microstructural characterisation of a P91 steel normalised and tempered at different temperatures

    International Nuclear Information System (INIS)

    Hurtado-Norena, C.; Danon, C.A.; Luppo, M.I.; Bruzzoni, P.

    2015-01-01

    9%Cr-1%Mo martensitic-ferritic steels are used in power plant components with operating temperatures of around 600 deg. C because of their good mechanical properties at high temperature as well as good oxidation resistance. These steels are generally used in the normalised and tempered condition. This treatment results in a structure of tempered lath martensite where the precipitates are distributed along the lath interfaces and within the martensite laths. The characterisation of these precipitates is of fundamental importance because of their relationship with the creep behaviour of these steels in service. In the present work, the different types of precipitates found in these steels have been studied on specimens in different metallurgical conditions. The techniques used in this investigation were X-ray diffraction with synchrotron light, scanning electron microscopy, energy dispersive microanalysis and transmission electron microscopy. (authors)

  13. Influence of different etchants on the representation of microstructures in nickel alloys; Einfluss verschiedener Aetzmittel auf die Gefuegedarstellung in Nickellegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Speicher, Magdalena; Scheck, Rudi; Maile, Karl [Stuttgart Univ. (Germany). Materialpruefungsanstalt

    2016-04-15

    This work presents a comparison of selected nickel alloys of the same condition which were treated by means of specifically chosen etching techniques. Microstructures on microscope images of wrought Alloy 617, a casting variant of Alloy 625, a polycrystalline casting alloy IN-738 LC, as well as of a monocrystalline superalloy CM 247 LC SX, respectively, are juxtaposed and evaluated. This approach allows for a comprehensive optical microscopy characterization of the characteristic microstructural features.

  14. Seed metabolomic study reveals significant metabolite variations and correlations among different soybean cultivars.

    Science.gov (United States)

    Lin, Hong; Rao, Jun; Shi, Jianxin; Hu, Chaoyang; Cheng, Fang; Wilson, Zoe A; Zhang, Dabing; Quan, Sheng

    2014-09-01

    Soybean [Glycine max (L.) Merr.] is one of the world's major crops, and soybean seeds are a rich and important resource for proteins and oils. While "omics" studies, such as genomics, transcriptomics, and proteomics, have been widely applied in soybean molecular research, fewer metabolomic studies have been conducted for large-scale detection of low molecular weight metabolites, especially in soybean seeds. In this study, we investigated the seed metabolomes of 29 common soybean cultivars through combined gas chromatography-mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry. One hundred sixty-nine named metabolites were identified and subsequently used to construct a metabolic network of mature soybean seed. Among the 169 detected metabolites, 104 were found to be significantly variable in their levels across tested cultivars. Metabolite markers that could be used to distinguish genetically related soybean cultivars were also identified, and metabolite-metabolite correlation analysis revealed some significant associations within the same or among different metabolite groups. Findings from this work may potentially provide the basis for further studies on both soybean seed metabolism and metabolic engineering to improve soybean seed quality and yield. © 2014 Institute of Botany, Chinese Academy of Sciences.

  15. Seed metabolomic study reveals significant metabolite variations and correlations among different soybean cultivars

    Institute of Scientific and Technical Information of China (English)

    Hong Lin; Jun Rao; Jianxin Shi; Chaoyang Hu; Fang Cheng; Zoe AWilson; Dabing Zhang; Sheng Quan

    2014-01-01

    Soybean [Glycine max (L.) Merr.] is one of the world’s major crops, and soybean seeds are a rich and important resource for proteins and oils. While “omics”studies, such as genomics, transcriptomics, and proteomics, have been widely applied in soybean molecular research, fewer metabolomic studies have been conducted for large-scale detection of low molecular weight metabolites, especial y in soybean seeds. In this study, we investigated the seed metabolomes of 29 common soybean cultivars through combined gas chromatography-mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry. One hundred sixty-nine named metabolites were identified and subsequently used to construct a metabolic network of mature soybean seed. Among the 169 detected metabolites, 104 were found to be significantly variable in their levels across tested cultivars. Metabolite markers that could be used to distinguish genetical y related soybean cultivars were also identified, and metabolite-metabolite correlation analysis revealed some significant associations within the same or among different metabolite groups. Findings from this work may potentially provide the basis for further studies on both soybean seed metabolism and metabolic engineering to improve soybean seed quality and yield.

  16. Functional significance of genetically different symbiotic algae Symbiodinium in a coral reef symbiosis.

    Science.gov (United States)

    Loram, J E; Trapido-Rosenthal, H G; Douglas, A E

    2007-11-01

    The giant sea anemone Condylactis gigantea associates with members of two clades of the dinoflagellate alga Symbiodinium, either singly or in mixed infection, as revealed by clade-specific quantitative polymerase chain reaction of large subunit ribosomal DNA. To explore the functional significance of this molecular variation, the fate of photosynthetically fixed carbon was investigated by (14)C radiotracer experiments. Symbioses with algae of clades A and B released ca. 30-40% of fixed carbon to the animal tissues. Incorporation into the lipid fraction and the low molecular weight fraction dominated by amino acids was significantly higher in symbioses with algae of clade A than of clade B, suggesting that the genetically different algae in C. gigantea are not functionally equivalent. Symbioses with mixed infections yielded intermediate values, such that this functional trait of the symbiosis can be predicted from the traits of the contributing algae. Coral and sea anemone symbioses with Symbiodinium break down at elevated temperature, a process known as 'coral bleaching'. The functional response of the C. gigantea symbiosis to heat stress varied between the algae of clades A and B, with particularly depressed incorporation of photosynthetic carbon into lipid of the clade B algae, which are more susceptible to high temperature than the algae of clade A. This study provides a first exploration of how the core symbiotic function of photosynthate transfer to the host varies with the genotype of Symbiodinium, an algal symbiont which underpins corals and, hence, coral reef ecosystems.

  17. MR first pass perfusion of benign and malignant cardiac tumours - significant differences and diagnostic accuracy

    International Nuclear Information System (INIS)

    Bauner, K.U.; Picciolo, M.; Theisen, D.; Sandner, T.A.; Reiser, M.F.; Huber, A.M.; Sourbron, S.; Schmitz, C.

    2012-01-01

    To determine the diagnostic value of magnetic resonance (MR) first pass perfusion in the differentiation of benign and malignant cardiac tumours. 24 patients with cardiac tumours (11 malignant, histopathological correlation present in all cases) were examined using MRI. In addition to morphological sequences a saturation-recovery T1w-GRE technique was implemented for tumour perfusion. The maximum relative signal enhancement (RSE[%]) and the slope of the RSE t -curve (slopeRSE[%/s]) of tumour tissue were assessed. A t-test was used to identify significant differences between benign and malignant tumours. Sensitivities and specificities were calculated for detection of malignant lesions and were compared with the sensitivity and specificity based on solely morphological image assessment. The RSE and slopeRSE of malignant cardiac tumours were significantly higher compared with benign lesions (p < 0.001 and p < 0.001). The calculated sensitivities and specificities of RSE and slopeRSE for identification of malignant lesions were 100% and 84.6% and 100% and 92.3%, respectively with cut-off values of 80% and 6%/s. The sensitivity and specificity for identification of malignant lesions on the basis of morphological imaging alone were 90.9% and 69.2%. With first pass perfusion, malignant cardiac masses can be identified with higher sensitivity and specificity compared with morphological image assessment alone. (orig.)

  18. Statistically significant faunal differences among Middle Ordovician age, Chickamauga Group bryozoan bioherms, central Alabama

    Energy Technology Data Exchange (ETDEWEB)

    Crow, C.J.

    1985-01-01

    Middle Ordovician age Chickamauga Group carbonates crop out along the Birmingham and Murphrees Valley anticlines in central Alabama. The macrofossil contents on exposed surfaces of seven bioherms have been counted to determine their various paleontologic characteristics. Twelve groups of organisms are present in these bioherms. Dominant organisms include bryozoans, algae, brachiopods, sponges, pelmatozoans, stromatoporoids and corals. Minor accessory fauna include predators, scavengers and grazers such as gastropods, ostracods, trilobites, cephalopods and pelecypods. Vertical and horizontal niche zonation has been detected for some of the bioherm dwelling fauna. No one bioherm of those studied exhibits all 12 groups of organisms; rather, individual bioherms display various subsets of the total diversity. Statistical treatment (G-test) of the diversity data indicates a lack of statistical homogeneity of the bioherms, both within and between localities. Between-locality population heterogeneity can be ascribed to differences in biologic responses to such gross environmental factors as water depth and clarity, and energy levels. At any one locality, gross aspects of the paleoenvironments are assumed to have been more uniform. Significant differences among bioherms at any one locality may have resulted from patchy distribution of species populations, differential preservation and other factors.

  19. Clinical Significance and Characteristic Clinical Differences of Cytolytic Vaginosis in Recurrent Vulvovaginitis.

    Science.gov (United States)

    Yang, Shuhua; Zhang, Yuexiang; Liu, Ying; Wang, Jianhong; Chen, Shuqin; Li, Shuxia

    2017-01-01

    The study aimed to evaluate whether cytolytic vaginosis (CV) has important clinical implications for recurrent vulvovaginitis and to identify clinical differences between CV and vulvovaginal candidosis (VVC). Medical histories, physical examinations and laboratory findings were used to diagnose and assess the prevalence rates of various vulvovaginal infections among 536 women with recurrent vulvovaginitis. Chi-square and Fisher exact tests were used to compare age, menstrual cycle phase at episode onset, symptoms/signs of infection and discharge characteristics between CV and VVC with single infection. Among the 484 women with a single-infection recurrent vulvovaginitis, the prevalence of CV (n = 143; 26.7%) was second only to VVC (n = 196; 36.6%). CV symptoms occurred predominantly during the ovulatory and luteal phases. Meanwhile, VVC episodes were not concentrated premenstrually, but rather occurred throughout the menstrual cycle. Significant differences were found in the vaginal pH, discharge characteristics and frequency of inflammatory symptoms between the 2 groups. CV is clinically important, because it is a common cause of recurrent vulvovaginitis. To distinguish CV from VVC, gynecologists should consider the patient's medical history, physical and laboratory findings, vaginal pH and vaginal discharge characteristics. © 2016 S. Karger AG, Basel.

  20. Associations between insulin action and integrity of brain microstructure differ with familial longevity and with age

    DEFF Research Database (Denmark)

    Akintola, Abimbola A; van den Berg, Annette; van Buchem, Mark A

    2015-01-01

    [fasted glucose and glucose area-under-the-curve (AUC)], insulin resistance [fasted insulin, AUCinsulin, and homeostatic model assessment of insulin resistance (HOMA-IR)], and pancreatic Beta cell secretory capacity (insulinogenic index). 3 Tesla MRI and Magnetization Transfer (MT) imaging MT-ratio (MTR......-height in gray and white matter was inversely associated with AUCinsulin, fasted insulin, HOMA-IR and insulinogenic-index (all p 65 years): in younger controls, significantly stronger inverse associations were observed between MTR peak-height and fasted glucose......, AUCglucose, fasted insulin, AUCinsulin and HOMA-IR in gray matter; and for AUCglucose, fasted insulin and HOMA-IR in white matter (all P-interaction

  1. Liquid Zn assisted embrittlement of advanced high strength steels with different microstructures

    Science.gov (United States)

    Jung, Geunsu; Woo, In Soo; Suh, Dong Woo; Kim, Sung-Joon

    2016-03-01

    In the present study, liquid metal embrittlement (LME) phenomenon during high temperature deformation was investigated for 3 grades of Zn-coated high strength automotive steel sheets consisting of different phases. Hot tensile tests were conducted for each alloy to compare their LME sensitivities at temperature ranges between 600 and 900 °C with different strain rates. The results suggest that Zn embrittles all the Fe-alloy system regardless of constituent phases of the steel. As hot tensile temperature and strain rate increase, LME sensitivity increases in every alloy. Furthermore, it is observed that the critical strain, which is experimentally thought to be 0.4% of strain at temperatures over 700 °C, is needed for LME to occur. It is observed via TEM work that Zn diffuses along grain boundaries of the substrate alloy when the specimen is strained at high temperatures. When the specimen is exposed to the strain more than 0.4% at over 700 °C, the segregation level of Zn at grain boundaries seems to become critical, leading to occurrence of LME cracks.

  2. Significant profile differences among male and female adventure tourists in Pretoria, South Africa

    Directory of Open Access Journals (Sweden)

    Melissa Jeanette Lötter

    2014-01-01

    Full Text Available Different adventure activities/experiences evolve because individuals, their motives, behaviours, and experiences differ and change over time. This notion illustrates the broad nature of adventure tourism and its links with other forms of tourism. In turn, adventure tourism companies are compelled to promote/sell an array of activities/experiences to a diverse range of markets as novel and exclusive experiences to facilitate the growth of adventure holidays (Swarbrooke et al., 2003. To assist adventure tourism companies in achieving effective marketing strategies, the study’s objective is to identify significant sociopsychological profile differences among male and female adventure tourists in Pretoria, South Africa. Furthermore, to facilitate the comparison of adventure tourists’ profiles, an equal number of respondents were male (117 and female (117, which provided a 93.6% response rate. In comparison to female respondents, male respondents prefer winter as a season to participate in hard/high-risk adventure activities when they are with or without their family, and they participate in adventure activities for travelling and socialising purposes. Whereas, female respondents predominantly regard scuba-diving, abseiling, and helicopter flights as a hard/high-risk adventure activity, although these activities are generally regarded by the overall sample as being soft/low-risk adventure activities. Furthermore, even though females’ participation in adventure activities is sponsored, they did not participate or only participated in adventure activities once over the past year due to fear/risk and/or lack of skill. This study established that there is a need to further research adventure tourists’ profiles before it could be equally accepted and interpreted.

  3. Effect of sintering temperature on microstructure and transport properties of Li3xLa2/3-xTiO3 with different lithium contents

    International Nuclear Information System (INIS)

    Geng Hongxia; Lan Jinle; Mei Ao; Lin Yuanhua; Nan, C.W.

    2011-01-01

    Li 3x La 2/3-x TiO 3 (LLTO) powder with different lithium contents (nominal 3x = 0.03-0.75) was synthesized via a simple sol-gel route and then calcination of gel-derived precursor at 900 o C which was much below the calcination temperature required for synthesizing the LLTO powder via solid state reaction route. The LLTO powder of sub-micron sized particles, derived from such sol-gel method, showed almost no aggregation. Starting from the sol-gel-derived powder, the LLTO ceramics with different lithium contents were prepared at different sintering temperatures of 1250 and 1350 o C. It demonstrated that our sol-gel route is quite simple and convenient compared to the previous sol-gel method and requires lower temperature for the LLTO. Our results also illustrated that lithium content significantly affects the structure and ionic conductivity of the LLTO ceramics. The dependence of the ionic conductivity on the lithium content, lattice structure, microstructure and sintering temperature was investigated systematically.

  4. Microstructures and performance of CaO-based ceramic cores with different particle size distributions for investment casting

    Science.gov (United States)

    Zhou, P. P.; Wu, G. Q.; Tao, Y.; Cheng, X.; Zhao, J. Q.; Nan, H.

    2018-02-01

    A series of calcium-based ceramic cores for casting titanium alloy were prepared by mixing different amounts of coarse and fine powders through injection molding. The effects of particle size on the microstructures and properties of the ceramic cores were investigated using quantitative and statistical analysis methods. It is found that the shrinkage and room-temperature strength of the ceramic cores were enhanced as increasing the contents of fine particles. Moreover, the creep resistance of the ceramic cores increased initially and then decreased. The increase in the fine particle content of the cores reduced the number and mean diameter of pores after sintering. The grain boundary density decreased firstly and then increased. The flexural strength of the ceramic cores at room temperature decreased with increasing porosity of ceramic cores, whereas the creep resistance increased with decreasing grain boundary density. A core exhibiting the optimal property was obtained when mixing 65 wt% of coarse powders (75-150 μm) and 35 wt% of fine powders (25-48 μm).

  5. Effect of processing on microstructure and physical properties of three nickel-based superalloys with different hardening mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Strondl, Annika; Frommeyer, Georg [Department of Materials Technology, Max-Planck-Institut fuer Eisenforschung GmbH, Max-Planck-Strasse 1, D-40237 Duesseldorf (Germany); Klement, Uta [Department of Materials and Manufacturing Technology, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Milenkovic, Srdjan; Schneider, Andre

    2012-07-15

    The nickel-based superalloys Inconel alloy 600, Udimet alloy 720, and Inconel alloy 718 were produced by electron beam melting (EBM), casting, and directional solidification (DS). The distance between dendrites and the size of the precipitates indicated the difference in solidification rates between the three processes. In this study, the solidification rate was fastest with EBM, closely followed by casting, whereas it was much slower with DS. In the directional solidified materials the <100> direction was the fastest and thus, preferred growth direction. The EBM samples show a sharp (001)[100] texture in the building direction and in the two scanning directions of the electron beam. Macrosegregation was observed in some cast and directionally solidified samples, but not in the EBM samples. The melting temperatures are in good agreement with literature and the narrow melting interval of IN600 compare to UD720 and IN718 might reduce the risk of incipient melting during EBM processing. Porosity was observed in the EBM samples and the reasons are discussed. However, EBM seems to be a feasible process route to produce nickel-based superalloys with well-defined texture, no macrosegregation and a rapidly solidified microstructure. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Microstructures and creep properties of Mg–4Al–(1–4) La alloys produced by different casting techniques

    International Nuclear Information System (INIS)

    Bai Jing; Sun Yangshan; Xue Feng; Qiang Jing

    2012-01-01

    The microstructures, mechanical properties and creep resistance of Mg–4Al–(1–4) La alloys produced by permanent mold casting and high pressure die casting (HPDC) were investigated. In addition to solute atoms in α-Mg matrix, Al element may exist in the form of three different intermetallic phases in the present alloys depending on the experimental conditions. In both casting states, the increase of La addition results in a rise in the volume fraction of Al 11 La 3 eutectic, and simultaneously Mg 17 Al 12 phase, including divorced eutectic in as-cast state and discontinuous precipitation after creep, is suppressed until completely disappears. This leads to a gradual increase in creep resistance. The formation of more Mg 17 Al 12 phase in HPDC alloys is considered a major factor in causing their worse creep properties by comparison with that of the permanent mold casting alloys when La content is in a lower level below 2 wt.%. By contrast, the HPDC alloys show better creep resistance with La content added above 2 wt.% owing to the formation of denser network distribution of Al 11 La 3 phase along grain/dendrite boundaries as a result of more rapid solidification rate and higher solidification pressure. For the alloys studied, grain/dendrite boundary sliding is suggested to be a possible controlling mechanism responsible for creep deformation at elevated temperatures.

  7. Microstructural changes across different clinical milestones of disease in amyotrophic lateral sclerosis.

    Directory of Open Access Journals (Sweden)

    Francesca Trojsi

    Full Text Available Neurodegenerative process in amyotrophic lateral sclerosis (ALS has been proven to involve several cortical and subcortical brain regions within and beyond motor areas. However, how ALS pathology spreads progressively during disease evolution is still unknown. In this cross-sectional study we investigated 54 ALS patients, divided into 3 subsets according to the clinical stage, and 18 age and sex-matched healthy controls, by using tract-based spatial statistics (TBSS diffusion tensor imaging (DTI and voxel-based morphometry (VBM analyses. We aimed to identify white (WM and gray matter (GM patterns of disease distinctive of each clinical stage, corresponding to specific clinical milestones. ALS cases in stage 2A (i.e., at diagnosis were characterized by GM and WM impairment of left motor and premotor cortices and brainstem at ponto-mesenchephalic junction. ALS patients in clinical stage 2B (with impairment of two functional regions exhibited decreased fractional anisotropy (FA (p<0.001, uncorrected and increased mean (MD and radial diffusivity (RD (p<0.001, uncorrected in the left cerebellar hemisphere and brainstem precerebellar nuclei, as well as in motor areas, while GM atrophy (p<0.001, uncorrected was detected only in the left inferior frontal gyrus and right cuneus. Finally, ALS patients in stage 3 (with impairment of three functional regions exhibited decreased FA and increased MD and RD (p<0.05, corrected within WM underneath bilateral pre and postcentral gyri, corpus callosum midbody, long associative tracts and midbrain, while no significant clusters of GM atrophy were observed. Our findings reinforce the hypothesis that the neurodegenerative process propagates along the axonal pathways and develops beyond motor areas from early stages, involving progressively several frontotemporal regions and their afferents and efferents, while the detection of GM atrophy in earlier stages and its disappearance in later stages may be the result of

  8. Oral challenges with four apple cultivars result in significant differences in oral allergy symptoms.

    Science.gov (United States)

    Nybom, Hilde; Cervin-Hoberg, Charlotte; Andersson, Morgan

    2013-01-01

    We analyzed the hypoallergenic potential of a recently bred apple selection with unusually low content of Mal d 1, using an oral challenge model with three additional apple cultivars for comparison. Sixty-six birch pollen-allergic individuals with a history of oral allergy syndrome after apple intake were subjected to a double-blind oral provocation with two apple cultivars (B:0654 and 'Discovery'). Thirteen also tested two other apple cultivars ('Ingrid Marie' and 'Gloster'). Three doses were given consecutively, 30 min apart: 10 g without peel, and 10 and 50 g with peel. A final assessment was conducted 30 min after the last intake. Oral symptoms were graded from 0 to 5. Total oral symptom score (TOS) included all scores for each cultivar at all time points. B:0654 induced significantly higher TOS than 'Discovery' when tested by 66 individuals, in spite of its lower Mal d 1 content. TOS values were higher in females and increased with increasing age of the individuals when challenged with 'Discovery'. Among the 13 individuals who tested all four cultivars, B:0654 produced a higher score after the second dose compared to 'Ingrid Marie'. This was also the case after the third dose compared to 'Ingrid Marie' and 'Gloster', and again 30 min after the last intake compared to each of the other three cultivars, as well as a higher TOS compared to each of the other three cultivars (all p safe and well tolerated, and produced significant differences among the apple cultivars. Contrary to expectations, B:0654 was less well tolerated than the other three cultivars. Copyright © 2013 S. Karger AG, Basel.

  9. Composition and microstructure of zirconium and hafnium germanates obtained by different chemical routes

    International Nuclear Information System (INIS)

    Utkin, A.V.; Prokip, V.E.; Baklanova, N.I.

    2014-01-01

    The phase composition and morphology of zirconium and hafnium germanates synthesized by ceramic and co-precipitation routes were studied. The products were characterized using high-temperature X-ray diffraction analysis (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and thermal (TG/DTA) analysis. To investigate the phase composition and stoichiometry of compounds the unit cell parameters were refined by full-profile Rietveld XRD analysis. The morphology of products and its evolution during high-temperature treatment was examined by SEM analysis. It was stated that there is the strong dependence of the phase composition and morphology of products on the preparation route. The ceramic route requires a multi-stage high-temperature treatment to obtain zirconium and hafnium germanates of 95% purity or more. Also, there are strong diffusion limitations to obtain hafnium germanate Hf 3 GeO 8 by ceramic route. On the contrary, the co-precipitation route leads to the formation of nanocrystalline single phase germanates of stoichiometric composition at a relatively low temperatures (less than 1000 °C). The results of quantitative XRD analysis showed the hafnium germanates are stoichiometric compounds in contrast to zirconium germanates that form a set of solid solutions. This distinction may be related to the difference in the ion radii of Zr and Hf. - Graphical abstract: The phase composition and morphology of zirconium and hafnium germanates synthesized by ceramic and co-precipitation routes were studied. It was stated that there is the strong dependence of the phase composition and morphology of products on the preparation route. Display Omitted - Highlights: • Zr and Hf germanates were synthesized by ceramic and co-precipitation routes. • The morphology of products depends on the synthesis parameters. • Zirconium germanates forms a set of solid solutions. • Hafnium germanates are stoichiometric compounds

  10. Cost Minimization Analysis of Different Strategies of Management of Clinically Significant Scorpion Envenomation Among Pediatric Patients.

    Science.gov (United States)

    Sinha, Madhumita; Quan, Dan; McDonald, Fred W; Valdez, André

    2016-12-01

    Scorpion antivenom was recently approved for use in patients with clinically significant scorpion envenomation in the United States; no formal economic analysis on its impact on cost of management has been performed. Three different strategies of management of scorpion envenomation with systemic neurotoxic symptoms in children were compared for cost minimization from a societal perspective. In strategy I, patients were managed with supportive care only without antivenom. In strategy II, an aggressive strategy of full-dose antivenom (initial dose of 3 vials with the use of additional vials administered 1 vial at a time) was considered. In strategy III, a single-vial serial antivenom dosing strategy titrated to clinical response was considered. Clinical probabilities for the different strategies were obtained from retrospective review of medical records of patients with scorpion envenomation over a 10-year period at our institution. Baseline cost values were obtained from patient reimbursement data from our institution. In baseline analysis, strategy I of supportive care only with no antivenom was least costly at US $3466.50/patient. Strategy III of single-vial serial dosing was intermediate but less expensive than strategy II of full-dose antivenom, with an incremental cost of US $3171.08 per patient. In a 1-way sensitivity analysis, at a threshold antivenom cost of US $1577.87, strategy III of single-vial serial dosing became the least costly strategy. For children with scorpion envenomation, use of a management strategy based on serial dosing of antivenom titrated to clinical response is less costly than a strategy of initial use of full-dose antivenom.

  11. [Different aluminum adjuvants significantly enhances the effect of immunization on Brucella Omp31].

    Science.gov (United States)

    Qing, Rui; Xiang, Qingke; Liu, Zhongqi; Xiao, Fei; Yang, Fan

    2018-02-01

    Objective To investigate the effect of aluminum phosphate (AP) and aluminum hydroxide (AH) as adjuvants on Brucella outer membrane protein 31 (Omp31) in inducing humoral and cellular immune responses and immune protection. Methods AP and AH adjuvants were prepared and separately mixed with Brucella Omp31 protein to measure the adsorption rates. The AP- and AH-absorbed Omp31 protein were intraperitoneally injected into BLAB/c mice at 0, 2, and 4 weeks, and meanwhile, unabsorbed Omp31 protein and PBS were used as controls. The levels of serum IgG, IgG1, IgG2a and genital tract secretion sIgA were determined by ELISA at 0, 2, 4 and 6 weeks. Spleen cells were collected for culture at 6 weeks, and the cells were stimulated by Omp31 for 48 hours followed by the analysis of IFN-γ and IL-10 levels in the supernatants by ELISA, and the determination of lymphocyte proliferation by CCK-8 assay. The mice were challenged with Brucella at 6 weeks, and bacterial content in spleen tissue was determined 1 and 2 weeks later. Results AP and AH could absorb over 70% and 85% of the Omp31 protein, respectively, for solutions at all the tested concentrations. ELISA suggested that serum IgG, IgG1, IgG2a and genital tract sIgA levels peaked 2 weeks after the last immunization for both AP and AH groups, and antibody level was higher in the AP and AH groups than the control groups, and higher in the AH group than in the AP group. CCK-8 assay showed that the proliferating rate of lymphocytes induced by the AH group was significantly higher than that by the AP group, and the AH group also showed significantly higher IFN-γ level in the supernatant than the AP group, but no significant difference in IL-10 level. The AH group had remarkably lower bacterial load in the spleen than the AP group 2 weeks after challenged by Brucella 16M strain. Conclusion Both AP and AH adjuvants effectively enhanced immunogenicity and immune protection of the Brucella Omp31 protein, and AH was superior to AP in

  12. Development of microstructure in thermomechanical processing of zirconium alloys

    International Nuclear Information System (INIS)

    Jha, S.K.; Saibaba, N.; Jayaraj, R.N.

    2009-01-01

    Zirconium based alloys are used for the manufacture of fuel tubes pressure tubes calandria tubes and other components of Pressurized Heavy Water Reactors (PHWRS). In single or two phase zirconium alloy system a variety of microstructure can be generated by suitable heat treatments by the process of equilibrium and non equilibrium phase transformations Microstructure can also be modified by alloying with α and β stabilizers. The microstructure in Zr alloys could be single hexagonal phase (α alloys) two phase bcc and hexagonal (α + β alloys) phase, single metastable martensitic microstructure and β with ω phase. The microstructural and micro textural evolution during thermo mechanical treatments depends strongly on such initial microstructure. Hot extrusion is a significant bulk deformation step which decides the initial microstructure of the alloy. It is carried out at elevated temperature i e above the recrystallization temperature, which enable imposition of large strains in single step. This deformation causes a significant change in the microstructure of the material and depends on extrusion process parameters such as temperature, strain rate (Ram speed), reduction ratio etc. In the present paper development of microstructures, microtexture and texture have been examined. An attempt is also made to optimise the hot working parameters for different Zirconium alloys with help of these studies. (author)

  13. TNF-α in CRPS and 'normal' trauma--significant differences between tissue and serum.

    Science.gov (United States)

    Krämer, Heidrun H; Eberle, Tatiana; Uçeyler, Nurcan; Wagner, Ina; Klonschinsky, Thomas; Müller, Lars P; Sommer, Claudia; Birklein, Frank

    2011-02-01

    Posttraumatic TNF-alpha signaling may be one of the factors responsible for pain and hyperalgesia in complex regional pain syndromes (CRPS). In order to further specify the role of TNF-alpha we investigated tissue (skin) and serum concentrations in three different patient groups: patients with osteoarthritis and planned surgery, with acute traumatic upper limb bone fracture waiting for surgery, and with CRPS I. Thirty patients (10 in each group) were recruited. Mean CRPS duration was 36.1 ± 8.1 weeks (range 8- 90 weeks). Skin punch biopsies were taken at the beginning of the surgery in osteoarthritis and fracture patients and from the affected side in CRPS patients. Blood samples were taken before the respective procedures. Skin and serum TNF-alpha levels were quantified by ELISA. Compared to patients with osteoarthritis, skin TNF-alpha was significantly elevated in CRPS (pCRPS patients was higher than in patients with acute bone fracture (pCRPS, and lower in fracture patients (pCRPS patients. This increase persists for months after limb trauma and may offer the opportunity for targeted treatment. Copyright © 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  14. Scratch deformation behavior of thermoplastic materials with significant differences in ductility

    International Nuclear Information System (INIS)

    Hadal, R.S.; Misra, R.D.K.

    2005-01-01

    A comparative study of the scratch deformation behavior of neat ethylene-propylene copolymers and polypropylene with significant differences in ductility is made by combining morphological examination by electron microscopy and scratch deformation parameters by atomic force microscopy. Also, the deformation behavior during scratch tests is examined for their respective long and short chain polymers. The ability of polymeric materials to resist scratch deformation under identical scratch test conditions follows the sequence (from maximum resistance to minimum resistance): short chain polypropylene > long chain polypropylene > short chain ethylene-propylene > long chain ethylene-propylene. The scratch tracks in ethylene-propylene copolymers were characterized by a consecutive parabolic pattern containing voids, while polypropylenes exhibited zig-zag periodic scratch tracks. The greater plastic flow in ethylene-propylene copolymers is encouraged by the high ductility of the copolymer and the ability to nucleate microvoids. The quasi-static periodic scratch tracks are a consequence of sequential accumulation and release of tangential force and represents the stick-slip process. The susceptibility to scratch deformation is discussed in terms of modulus, elastic recovery, scratch hardness, and entanglement density of polymeric materials. A higher effective entanglement density and percentage crystallinity of short chain polymers is helpful in enhancing scratch resistance as compared to their respective long chain polymers

  15. No gender differences in prognosis and preventive treatment in patients with AMI without significant stenoses

    DEFF Research Database (Denmark)

    Hansen, Kim; Hvelplund, Anders; Abildstrøm, Steen Zabell

    2011-01-01

    : By compiling data from Danish registries, we identified 20,800 patients hospitalized with AMI during 2005-2007. We included the 834 women and 761 men without significant stenoses on CAG who were discharged and alive after 60 days. Main outcome measures: All-cause mortality, recurrent AMI, and redeeming...... a prescription for a lipid-lowering drug, beta-blocker, clopidogrel, or aspirin within 60 days of discharge. Results: During follow-up, 97 women and 60 men died, resulting in a crude female/male hazard ratio (HR) of 1.51 (95% CI 1.09-2.08). After adjustment for age, time-period, and comorbidity, the gender...... difference was attenuated (HR 1.22, 95% CI 0.86-1.72). AMI recurrence was experienced by 28 women and 29 men with a female/male HR 0.88 (95% CI 0.52-1.48). After multivariable adjustment results were similar (HR 0.84, 95% CI 0.50-1.43). More women than men redeemed a prescription for lipid-lowering drugs...

  16. Multi-scale modeling of elasto-plastic response of SnAgCu lead-free solder alloys at different ageing conditions: Effect of microstructure evolution, particle size effects and interfacial failure

    Energy Technology Data Exchange (ETDEWEB)

    Maleki, Milad; Cugnoni, Joel, E-mail: joel.cugnoni@epfl.ch; Botsis, John

    2016-04-20

    In microelectronics applications, SnAgCu lead-free solder joints play the important role of ensuring both the mechanical and electrical integrity of the components. In such applications, the SnAgCu joints are subjected to elevated homologous temperatures for an extended period of time causing significant microstructural changes and leading to reliability issues. In this study, the link between the change in microstructures and deformation behavior of SnAgCu solder during ageing is explained by developing a hybrid multi-scale microstructure-based modeling approach. Herein, the SnAgCu solder alloy is seen as a three phase metal matrix composite in which Ag{sub 3}Sn and Cu{sub 6}Sn{sub 5} hard intermetallics play the role of reinforcements and Sn the role of a ductile matrix. The hardening of the Sn matrix due to fine intermetallics in the eutectic mixture is modeled by incorporating the mean field effects of geometrically necessary dislocations. Subsequently, a two level homogenization procedure based on micromechanical finite element (FE) models is used to capture the interactions between the different phases. For this purpose, tomographic images of microstructures obtained by Focused Ion Beam (FIB) and synchrotron X-Ray in different ageing conditions are directly used to generate statistically representative volume elements (RVE) using 3D FE models. The constitutive behavior of the solder is determined by sequentially performing two scales of numerical homogenization at the eutectic level and then at the dendrite level. For simplification, the anisotropy of Sn as well as the potential recovery processes have been neglected in the modeling. The observed decrease in the yield strength of solder due to ageing is well captured by the adopted modeling strategy and allows explaining the different ageing mechanisms. Finally, the effects of potential debonding at the intermetallic particle-matrix interface as well as particle fracture on the overall strength of solder are

  17. Evolution of microstructure and residual stress on L1{sub 0} ordering in FePt thin films with different initial stress states

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, S.N., E-mail: pmami.hsiao@gmail.com [Department of Materials Science and Engineering, Feng Chia University, Taichung 407, Taiwan (China); Yuan, F.T. [iSentek Ltd., Advanced Sensor Laboratory, New Taipei City 221, Taiwan (China); Chen, S.K. [Department of Materials Science and Engineering, Feng Chia University, Taichung 407, Taiwan (China); Sun, A.C. [Department of Chemical Engineering and Materials Science, Yuan Ze University, Jungli 320, Taiwan (China); Su, S.H.; Chiu, K.F. [Department of Materials Science and Engineering, Feng Chia University, Taichung 407, Taiwan (China)

    2016-01-15

    We have characterized the dependence of microstructure, and internal strain/stress on L1{sub 0} ordering in 40 nm thick FePt films with different initial stresses. The microstructural and crystallographic results indicate that defect annihilation and grain growth induced an increase in tensile stress of ~1 GPa before extensive L1{sub 0} ordering. The induced tensile stress can efficiently facilitate the nucleation of L1{sub 0} phase owing to that the volume expansion of L1{sub 0} ordering and atomic rearrangement neutralizes the tensile stress. If the as-deposited FePt film has a highly compressive state, the induced tensile stress will be canceled out and ordering is retarded, which results in a higher ordering temperature. - Highlights: • Microstructure-stress connection in FePt films was studied. • Initial stress alters microstructure and stress evolution during annealing. • Densification induces tensile stress of ~1 GPa before extensive L1{sub 0} ordering. • Induced tensile stress can efficiently facilitate the nucleation of L1{sub 0} phase. • Compressively initial stress results in a higher ordering temperature .

  18. Effect of Different Chromium Additions on the Microstructure and Mechanical Properties of Multipass Weld Joint of Duplex Stainless Steel

    Science.gov (United States)

    Kang, Dong Hoon; Lee, Hae Woo

    2012-12-01

    The correlation between the mechanical properties and ferrite volume fraction (approximately 40, 50, and 60 Ferrite Number [FN]) in duplex stainless steel weld metals were investigated by changing the Cr content in filler wires with a flux-cored arc-welding (FCAW) process. The interpass temperature was thoroughly maintained under a maximum of 423 K (150 °C), and the heat input was also sustained at a level under 15 KJ/cm in order to minimize defects. The microstructure examination demonstrated that the δ-ferrite volume fraction in the deposited metals increased as the Cr/Ni equivalent ratio increased, and consequently, chromium nitride (Cr2N) precipitation was prone to occur in the ferrite domains due to low solubility of nitrogen in this phase. Thus, more dislocations are pinned by the precipitates, thereby lowering the mobility of the dislocations. Not only can this lead to the strength improvement, but also it can accentuate embrittlement of the weld metal at subzero temperature. Additionally, the solid-solution strengthening by an increase of Cr and Mo content in austenite phase depending on the reduction of austenite proportion also made an impact on the increase of the tensile and yield strength. On the other hand, the impact test (at 293 K, 223 K, and 173 K [20 °C, -50 °C, and -100 °C]) showed that the specimen containing about 40 to 50 FN had the best result. The absorbed energy of about 40 to 50 J sufficiently satisfied the requirements for industrial applications at 223 K (-50 °C), while the ductile-to-brittle transition behavior exhibited in weldment containing 60 FN. As the test temperature decreased under 223 K (-50 °C), a narrow and deep dimple was transformed into a wide and shallow dimple, and a significant portion of the fracture surface was occupied by a flat cleavage facet with river patterns.

  19. Hemispheric Differences in White Matter Microstructure between Two Profiles of Children with High Intelligence Quotient vs. Controls: A Tract-Based Spatial Statistics Study

    Science.gov (United States)

    Nusbaum, Fanny; Hannoun, Salem; Kocevar, Gabriel; Stamile, Claudio; Fourneret, Pierre; Revol, Olivier; Sappey-Marinier, Dominique

    2017-01-01

    Objectives: The main goal of this study was to investigate and compare the neural substrate of two children's profiles of high intelligence quotient (HIQ). Methods: Two groups of HIQ children were included with either a homogeneous (Hom-HIQ: n = 20) or a heterogeneous IQ profile (Het-HIQ: n = 24) as defined by a significant difference between verbal comprehension index and perceptual reasoning index. Diffusion tensor imaging was used to assess white matter (WM) microstructure while tract-based spatial statistics (TBSS) analysis was performed to detect and localize WM regional differences in fractional anisotropy (FA), mean diffusivity, axial (AD), and radial diffusivities. Quantitative measurements were performed on 48 regions and 21 fiber-bundles of WM. Results: Hom-HIQ children presented higher FA than Het-HIQ children in widespread WM regions including central structures, and associative intra-hemispheric WM fasciculi. AD was also greater in numerous WM regions of Total-HIQ, Hom-HIQ, and Het-HIQ groups when compared to the Control group. Hom-HIQ and Het-HIQ groups also differed by their hemispheric lateralization in AD differences compared to Controls. Het-HIQ and Hom-HIQ groups showed a lateralization ratio (left/right) of 1.38 and 0.78, respectively. Conclusions: These findings suggest that both inter- and intra-hemispheric WM integrity are enhanced in HIQ children and that neural substrate differs between Hom-HIQ and Het-HIQ. The left hemispheric lateralization of Het-HIQ children is concordant with their higher verbal index while the relative right hemispheric lateralization of Hom-HIQ children is concordant with their global brain processing and adaptation capacities as evidenced by their homogeneous IQ. PMID:28420955

  20. Faculty Decisions on Serials Subscriptions Differ Significantly from Decisions Predicted by a Bibliometric Tool.

    Directory of Open Access Journals (Sweden)

    Sue F. Phelps

    2016-03-01

    of the faculty choices. The p-value for this relationship was less than 0.0001, also indicating that the result was not by chance. A quadratic model plotted alongside the previous linear model follows a similar pattern. The p-value of the comparison is 0.0002, which indicates the quadratic model’s fit cannot be explained by random chance. Main Results – The authors point out three outstanding findings. First, the match rate between faculty valuations and bibliometric scores for serials is 65%. This exceeds the 50% rate that would indicate random association, but also indicates a statistically significant difference between faculty and bibliometric valuations. Secondly, the match rate with the bibliometric scores for titles that faculty chose to keep (73% was higher than those they chose to cancel (54%. Thirdly, the match rate increased with higher bibliometric scores. Conclusions – Though the authors identify only a modest degree of similarity between faculty and bibliometric valuations of serials, it is noted that there is more agreement in the higher valued serials than the lower valued serials. With that in mind, librarians might focus faculty review on the lower scoring titles in the future, taking into consideration that unique faculty interests may drive selection at that level and would need to be balanced with the mission of the library.

  1. Significant regional differences in Denmark in outcome after cochlear implants in children

    DEFF Research Database (Denmark)

    Percy-Smith, Lone; Busch, Georg Walter; Sandahl, Minna

    2012-01-01

    The objectives of the present study were to study regional differences in outcome for a paediatric cochlear implant (CI) population after the introduction of universal neonatal hearing screening (UNHS) and bilateral implantation in Denmark....

  2. The differences between emission, waste, and a good, and their significance to waste management policy

    International Nuclear Information System (INIS)

    Holm-Mueller, K.

    1994-01-01

    This paper defines the transportability of solid waste as its major difference compared to emissions. Several specific possibilities for politics dealing with the problems of solid waste are deduced from this characteristic. The difference between solid waste and good lies in the valuation of objects. As is shown the negative valuation of waste has a great influence on the effect of possible politics derived in part one of this paper. (orig.) [de

  3. Field Dependence/Independence Cognitive Styles: Are They Significant at Different Levels of Vocabulary Knowledge?

    Science.gov (United States)

    Rostampour, Mohammad; Niroomand, Seyyedeh Mitra

    2014-01-01

    Cognitive styles influence the performance of language learners and can predict their success in the process of language learning. Considering field dependence/independence cognitive styles, this study aims at determining if they are significant in English vocabulary knowledge. A number of EFL university students took part in the study. The…

  4. What Makes Your Writing Style Unique? Significant Differences Between Two Famous Romanian Orators

    NARCIS (Netherlands)

    Dascalu, Mihai; Gifu, Daniela; Trausan-Matu, Stefan

    2016-01-01

    This paper introduces a novel, in-depth approach of analyzing the differences in writing style between two famous Romanian orators, based on automated textual complexity indices for Romanian language. The considered authors are: (a) Mihai Eminescu, Romania’s national poet and a

  5. Do Age and Sex of School Students Make Significant Difference in Their Multiple Intelligences?

    Science.gov (United States)

    Ravi, R.; Vedapriya, S. Gethsi

    2009-01-01

    Multiple Intelligences are a new educational theory proposed by Howard Gardner in 1983. Multiple intelligences describe an array of different kinds of intelligences exhibited by human beings. This theory consists of verbal-linguistic, logical and mathematics, visual and spatial, bodily kinesthetic, musical-rhythmic, intrapersonal, interpersonal,…

  6. Assay of serum ferritin by two different radioimmunometric methods and its clinical significance

    International Nuclear Information System (INIS)

    Kaltwasser, J.P.; Werner, E.; Gesellschaft fuer Strahlen- und Umweltforschung m.b.H., Frankfurt am Main

    1977-01-01

    Serum ferritin was measured by two different radioimmunometric methods a) the Addison assay, b) a commercial radioimmunoassay. Iron storage in the body was determined using 59 Fe. A dose correlation was found between serum ferritin and iron storage in the body. (AJ) [de

  7. Conventions of Courtship: Gender and Race Differences in the Significance of Dating Rituals

    Science.gov (United States)

    Jackson, Pamela Braboy; Kleiner, Sibyl; Geist, Claudia; Cebulko, Kara

    2011-01-01

    Dating rituals include dating--courtship methods that are regularly enacted. This study explores gender and race differences in the relative importance placed on certain symbolic activities previously identified by the dating literature as constituting such rituals. Using information collected from a racially diverse sample of college students (N…

  8. The significance of different diacylgycerol synthesis pathways on plant oil composition and bioengineering

    Directory of Open Access Journals (Sweden)

    Philip David Bates

    2012-07-01

    Full Text Available The unique properties of vegetable oils from different plants utilized for food, industrial feedstocks, and fuel is dependent on the fatty acid (FA composition of triacylglycerol (TAG. Plants can use two main pathways to produce diacylglycerol (DAG, the immediate precursor molecule to TAG synthesis: 1 De novo DAG synthesis, and 2 conversion of the membrane lipid phosphatidylcholine (PC to DAG. The FA esterified to PC are also the substrate for FA modification (e.g. desaturation, hydroxylation, etc., such that the FA composition of PC-derived DAG can be substantially different than that of de novo DAG. Since DAG provides two of the three FA in TAG, the relative flux of TAG synthesis from de novo DAG or PC-derived DAG can greatly affect the final oil FA composition. Here we review how the fluxes through these two alternate pathways of DAG/TAG synthesis are determined and present evidence that suggests which pathway is utilized in different plants. Additionally, we present examples of how the endogenous DAG synthesis pathway in a transgenic host plant can produce bottlenecks for engineering of plant oil FA composition, and discuss alternative strategies to overcome these bottlenecks to produce crop plants with designer vegetable oil compositions.

  9. 'It's Made a Huge Difference': Recognition, Rights and the Personal Significance of Civil Partnership

    OpenAIRE

    Beccy Shipman; Carol Smart

    2007-01-01

    In this paper we map briefly some of the arguments around the meaning and significance of the introduction of Civil Partnership in England and Wales, and in this way show how contested these meanings are with some groups profoundly against this legal reform and others supporting it, but for a mixture of reasons. We then turn to our empirical data based on interviews with same-sex couples to explore the extent to which these arguments and issues are part of the everyday decision making process...

  10. Significant Differences Characterise the Correlation Coefficients between Biocide and Antibiotic Susceptibility Profiles in Staphylococcus aureus.

    Science.gov (United States)

    Oggioni, Marco R; Coelho, Joana Rosado; Furi, Leonardo; Knight, Daniel R; Viti, Carlo; Orefici, Graziella; Martinez, Jose-Luis; Freitas, Ana Teresa; Coque, Teresa M; Morrissey, Ian

    2015-01-01

    There is a growing concern by regulatory authorities for the selection of antibiotic resistance caused by the use of biocidal products. We aimed to complete the detailed information on large surveys by investigating the relationship between biocide and antibiotic susceptibility profiles of a large number of Staphylococcus aureus isolates using four biocides and antibiotics commonly used in clinical practice. The minimal inhibitory concentration (MIC) for most clinically-relevant antibiotics was determined according to the standardized methodology for over 1600 clinical S. aureus isolates and compared to susceptibility profiles of benzalkonium chloride, chlorhexidine, triclosan, and sodium hypochlorite. The relationship between antibiotic and biocide susceptibility profiles was evaluated using non-linear correlations. The main outcome evidenced was an absence of any strong or moderate statistically significant correlation when susceptibilities of either triclosan or sodium hypochlorite were compared for any of the tested antibiotics. On the other hand, correlation coefficients for MICs of benzalkonium chloride and chlorhexidine were calculated above 0.4 for susceptibility to quinolones, beta-lactams, and also macrolides. Our data do not support any selective pressure for association between biocides and antibiotics resistance and furthermore do not allow for a defined risk evaluation for some of the compounds. Importantly, our data clearly indicate that there does not involve any risk of selection for antibiotic resistance for the compounds triclosan and sodium hypochlorite. These data hence infer that biocide selection for antibiotic resistance has had so far a less significant impact than feared.

  11. Controlling periodic ripple microstructure formation on 4H-SiC crystal with three time-delayed femtosecond laser beams of different linear polarizations.

    Science.gov (United States)

    He, Wanlin; Yang, Jianjun; Guo, Chunlei

    2017-03-06

    The control of laser-induced periodic ripple microstructures on 4H-SiC crystal surface is studied using temporally delayed collinear three femtosecond laser pulse trains linearly polarized in different directions. The ripple orientation appears to develop independent of the individual laser polarizations and exhibits non-monotonical change with variable time delays, whose variation tendency is also affected by the polarization intersection angles. Remarkably, the ripple period is observed to transfer from high- to low-spatial-frequency regions, accompanied by distinctly improved morphological uniformity and clearness. The results are satisfactorily interpreted based on a physical model of the surface wave excitation on a transient index metasurface, which is confirmed by further experiments. Our investigations indicate that transient noneqilibrium dynamics of the material surface provides an effective way to manipulate the laser-induced microstructures.

  12. Postexercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport Supplements.

    Science.gov (United States)

    Cramer, Michael J; Dumke, Charles L; Hailes, Walter S; Cuddy, John S; Ruby, Brent C

    2015-10-01

    A variety of dietary choices are marketed to enhance glycogen recovery after physical activity. Past research informs recommendations regarding the timing, dose, and nutrient compositions to facilitate glycogen recovery. This study examined the effects of isoenergetic sport supplements (SS) vs. fast food (FF) on glycogen recovery and exercise performance. Eleven males completed two experimental trials in a randomized, counterbalanced order. Each trial included a 90-min glycogen depletion ride followed by a 4-hr recovery period. Absolute amounts of macronutrients (1.54 ± 0.27 g·kg-1 carbohydrate, 0.24 ± 0.04 g·kg fat-1, and 0.18 ±0.03g·kg protein-1) as either SS or FF were provided at 0 and 2 hr. Muscle biopsies were collected from the vastus lateralis at 0 and 4 hr post exercise. Blood samples were analyzed at 0, 30, 60, 120, 150, 180, and 240 min post exercise for insulin and glucose, with blood lipids analyzed at 0 and 240 min. A 20k time-trial (TT) was completed following the final muscle biopsy. There were no differences in the blood glucose and insulin responses. Similarly, rates of glycogen recovery were not different across the diets (6.9 ± 1.7 and 7.9 ± 2.4 mmol·kg wet weight- 1·hr-1 for SS and FF, respectively). There was also no difference across the diets for TT performance (34.1 ± 1.8 and 34.3 ± 1.7 min for SS and FF, respectively. These data indicate that short-term food options to initiate glycogen resynthesis can include dietary options not typically marketed as sports nutrition products such as fast food menu items.

  13. Different extraction pretreatments significantly change the flavonoid contents of Scutellaria baicalensis

    Science.gov (United States)

    Yu, Chunhao; Qu, Fengyun; Mao, Yanyong; Li, Dong; Zhen, Zhong; Nass, Rachael; Calway, Tyler; Wang, Yunwei; Yuan, Chun-Su; Wang, Chong-Zhi

    2014-01-01

    Context Scutellaria baicalensis is one of the most commonly used medicinal herbs, especially in traditional Chinese medicine. However, compared to many pharmacological studies of this botanical, much less attention has been paid to the quality control of the herb’s pretreatment prior to extract preparation, an issue that may affect therapeutic outcomes. Objective The current study was designed to evaluate whether different pretreatment conditions change the contents of its four major flavonoids in the herb, i.e., two glycosides (baicalin and wogonoside) and two aglycons (baicalein and wogonin). Materials and methods An HPLC assay was used to quantify the contents of these four flavonoids. The composition changes of four flavonoids by different pretreatment conditions including solvent, treatment time, temperature, pH value, and herb/solvent ratio were evaluated. Results After selection of the first order time-curve kinetics, our data showed that at 50°C, 1:5 herb/water (in w/v) ratio and pH 6.67 yielded an optimal conversion rate from flavonoid glycosides to their aglycons. In this optimized condition, the contents of baicalin and wogonoside were decreased to 1/70 and 1/13, while baicalein and wogonin were increased 3.5 and 3.1 folds, respectively, compared to untreated herb. Discussion and conclusion The markedly variable conversion rates by different pretreatment conditions complicated the quality control of this herb, mainly due to the high amount of endogenous enzymes of S. baicalensis. Optimal pretreatment conditions obtained from this study could be used obtain the highest level of desired constituents to achieve better pharmacological effects. PMID:23738852

  14. Null hypothesis significance tests. A mix-up of two different theories

    DEFF Research Database (Denmark)

    Schneider, Jesper Wiborg

    2015-01-01

    criticisms raised against NHST. As practiced, NHST has been characterized as a ‘null ritual’ that is overused and too often misapplied and misinterpreted. NHST is in fact a patchwork of two fundamentally different classical statistical testing models, often blended with some wishful quasi......-Bayesian interpretations. This is undoubtedly a major reason why NHST is very often misunderstood. But NHST also has intrinsic logical problems and the epistemic range of the information provided by such tests is much more limited than most researchers recognize. In this article we introduce to the scientometric community...

  15. Biomedical research in france and brazil: an analysis of significant differences and ethical issues

    OpenAIRE

    Hervé Moizan

    2016-01-01

    At first sight, Brazil and France seem pretty distant from one another, but on the map, they are not separated by the Atlantic Ocean, but by the Oyapock River, located between the state of Amapa and French Guiana (French overseas department), creating a 730 km long international border. If the distance does exist, it is very different when we finely analyze some similarities in the field of biomedical research. France is the biggest country of Western Europe and covers 1/5 of the European ...

  16. Thermodynamic study of three pharmacologically significant drugs: Density, viscosity, and refractive index measurements at different temperatures

    International Nuclear Information System (INIS)

    Iqbal, Muhammad Javed; Chaudhry, Mansoora Ahmed

    2009-01-01

    Measurements of density, viscosity, and refractive index of three pharmacologically significant drugs, i.e. diclofenac sodium, cetrizine, and doxycycline have been carried in aqueous medium at T = (293.15 to 313.15) K. An automated vibrating-tube densimeter, viscometer, and refractometer are used in a concentration range from (7.5) . 10 -3 to 25 . 10 -3 ) mol . kg -1 . The precise density results are used to evaluate the apparent molar volume, partial molar volume, thermal expansion coefficient, partial molar expansivity, and the Hepler's constant. Viscosity results are used to calculate the Jones-Dole viscosity B-coefficient, free energy of activation of the solute and solvent, activation enthalpy, and activation entropy. The molar refractive indices of the drug solutions can be employed to calculate molar refraction. It is inferred from these results that the above mentioned drugs act as structure-making compounds due to hydrophobic hydration of the molecules in the drugs

  17. Significant gender difference in serum levels of fibroblast growth factor 21 in Danish children and adolescents

    DEFF Research Database (Denmark)

    Bisgaard, Amalie; Sørensen, Kaspar; Johannsen, Trine Holm

    2014-01-01

    children (21%) had levels below detection limit of assay. Baseline levels of FGF21 showed positive correlation with triglycerides, but no significant correlations were found between FGF21-concentration and body mass index (BMI), DXA-derived fat percentage, LDL- HDL- and non-HDL cholesterol, leptin......INTRODUCTION: Fibroblast Growth Factor 21 (FGF21) is a novel metabolic factor with effect on glucose and lipid metabolism, and shown to be elevated in diseases related to metabolic syndrome. Due to the increasing frequency of metabolic syndrome in the pediatric population, and as FGF21 studies...... in children are limited, we investigated baseline serum levels of FGF21 in healthy children during an oral glucose tolerance test. METHODS: A total of 179 children and adolescents from the COPENHAGEN Puberty Study were included. An OGTT with glucose and insulin measurements, a dual energy X-ray absorptiometry...

  18. Harvesting yeast (Saccharomyces cerevisiae) at different physiological phases significantly affects its functionality in bread dough fermentation.

    Science.gov (United States)

    Rezaei, Mohammad N; Dornez, Emmie; Jacobs, Pieter; Parsi, Anali; Verstrepen, Kevin J; Courtin, Christophe M

    2014-05-01

    Fermentation of sugars into CO2, ethanol and secondary metabolites by baker's yeast (Saccharomyces cerevisiae) during bread making leads to leavening of dough and changes in dough rheology. The aim of this study was to increase our understanding of the impact of yeast on dough related aspects by investigating the effect of harvesting yeast at seven different points of the growth profile on its fermentation performance, metabolite production, and the effect on critical dough fermentation parameters, such as gas retention potential. The yeast cells harvested during the diauxic shift and post-diauxic growth phase showed a higher fermentation rate and, consequently, higher maximum dough height than yeast cells harvested in the exponential or stationary growth phase. The results further demonstrate that the onset of CO2 loss from fermenting dough is correlated with the fermentation rate of yeast, but not with the amount of CO2 that accumulated up to the onset point. Analysis of the yeast metabolites produced in dough yielded a possible explanation for this observation, as they are produced in different levels depending on physiological phase and in concentrations that can influence dough matrix properties. Together, our results demonstrate a strong effect of yeast physiology at the time of harvest on subsequent dough fermentation performance, and hint at an important role of yeast metabolites on the subsequent gas holding capacity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. TIG AISI-316 welds using an inert gas welding chamber and different filler metals: Changes in mechanical properties and microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Pascual, M.; Salas, F.; Carcel, F.J.; Perales, M.; Sanchez, A.

    2010-07-01

    This report analyses the influence of the use of an inert gas welding chamber with a totally inert atmosphere on the microstructure and mechanical properties of austenitic AISI 316L stainless steel TIG welds, using AISI ER316L, AISI 308L and Inconel 625 as filler metals. When compared with the typical TIG process, the use of the inert gas chamber induced changes in the microstructure, mainly an increase in the presence of vermicular ferrite and ferrite stringers, what resulted in higher yield strengths and lower values of hardness. Its effect on other characteristics of the joins, such as tensile strength, depended on the filler metal. The best combination of mechanical characteristics was obtained when welding in the inert gas chamber using Inconel 625 as filler metal. (Author). 12 refs.

  20. Strain Rate Dependent Deformation of a Polymer Matrix Composite with Different Microstructures Subjected to Off-Axis Loading

    Directory of Open Access Journals (Sweden)

    Xiaojun Zhu

    2014-01-01

    Full Text Available This paper aims to investigate the comprehensive influence of three microstructure parameters (fiber cross-section shape, fiber volume fraction, and fiber off-axis orientation and strain rate on the macroscopic property of a polymer matrix composite. During the analysis, AS4 fibers are considered as elastic solids, while the surrounding PEEK resin matrix exhibiting rate sensitivities are described using the modified Ramaswamy-Stouffer viscoplastic state variable model. The micromechanical method based on generalized model of cells has been used to analyze the representative volume element of composites. An acceptable agreement is observed between the model predictions and experimental results found in the literature. The research results show that the stress-strain curves are sensitive to the strain rate and the microstructure parameters play an important role in the behavior of polymer matrix.

  1. Microstructure and Mechanical Properties of Welds of Al - Mg - Si Alloys After Different Modes of Impulse Friction Stir Welding

    Science.gov (United States)

    Kondrat'ev, S. Yu.; Morozova, Yu. N.; Golubev, Yu. A.; Hantelmann, C.; Naumov, A. A.; Mikhailov, V. G.

    2018-03-01

    Welded joints of aluminum alloy 6082-T6 formed by the method of impulse friction stir welding are studied. The effect of the power and frequency of the pulses on the microstructure and mechanical properties of the welded joints is determined. Application of an additional pulse during the welding affects the surface quality and the shape of the weld, the distribution of the oxide layer and of particles of the hardening phase, and the grain size in the zone of dynamic recrystallization.

  2. Experimental study on microstructure characters of foamed lightweight soil

    Science.gov (United States)

    Qiu, Youqiang; Li, Yongliang; Li, Meixia; Liu, Yaofu; Zhang, Liujun

    2018-01-01

    In order to verify the microstructure of foamed lightweight soil and its characters of compressive strength, four foamed lightweight soil samples with different water-soild ratio were selected and the microstructure characters of these samples were scanned by electron microscope. At the same time, the characters of compressive strength of foamed lightweight soil were analyzed from the microstructure. The study results show that the water-soild ratio has a prominent effect on the microstructure and compressive strength of foamed lightweight soil, with the decrease of water-solid ratio, the amount and the perforation of pores would be reduced significantly, thus eventually forming a denser and fuller interior structure. Besides, the denser microstructure and solider pore-pore wall is benefit to greatly increase mechanical intensity of foamed lightweight soil. In addition, there are very few acicular ettringite crystals in the interior of foamed lightweight soil, its number is also reduced with the decrease in water-soild ratio.

  3. Thermodynamic study of three pharmacologically significant drugs: Density, viscosity, and refractive index measurements at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Muhammad Javed [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)], E-mail: mjiqauchem@yahoo.com; Chaudhry, Mansoora Ahmed [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2009-02-15

    Measurements of density, viscosity, and refractive index of three pharmacologically significant drugs, i.e. diclofenac sodium, cetrizine, and doxycycline have been carried in aqueous medium at T = (293.15 to 313.15) K. An automated vibrating-tube densimeter, viscometer, and refractometer are used in a concentration range from (7.5) . 10{sup -3} to 25 . 10{sup -3}) mol . kg{sup -1}. The precise density results are used to evaluate the apparent molar volume, partial molar volume, thermal expansion coefficient, partial molar expansivity, and the Hepler's constant. Viscosity results are used to calculate the Jones-Dole viscosity B-coefficient, free energy of activation of the solute and solvent, activation enthalpy, and activation entropy. The molar refractive indices of the drug solutions can be employed to calculate molar refraction. It is inferred from these results that the above mentioned drugs act as structure-making compounds due to hydrophobic hydration of the molecules in the drugs.

  4. Antimicrobial Resistance Patterns in Women with Positive Urine Culture: Does Menopausal Status Make a Significant Difference?

    Directory of Open Access Journals (Sweden)

    Pawel Miotla

    2017-01-01

    Full Text Available Aim. Urinary tract infection (UTI is considered one of the most common bacterial infections in women. The aim of this study was to investigate the types of uropathogens present, as well as the degree of antimicrobial drug resistance seen among premenopausal (n=2748 and postmenopausal (n=1705 women with uncomplicated UTI. Methods. Urinary samples (n=4453 collected from women with UTI were analyzed in terms of uropathogens present. These were considered as positive if bacterial growth was ≥105 colony forming units (CFUs/mL. Susceptibility and resistance testing for commonly used antibiotics was subsequently assessed. Results. The most common uropathogens cultured from urine samples were Escherichia coli (65.5%, followed by Enterococcus faecalis (12.2%, Klebsiella pneumoniae (4.7%, and Proteus mirabilis (4.2%. The resistance to ampicillin exceeded 40%, independently of menopausal status. Of note, resistance to ciprofloxacin exceeded 25% among postmenopausal patients. Moreover, resistance of all uropathogens to commonly used antimicrobials was significantly higher in postmenopausal women. Conclusion. Due to the high resistance rate, ampicillin, ciprofloxacin, and the trimethoprim/sulfamethoxazole combination should be avoided in treating postmenopausal women affected by UTI without being indicated by initial urine culture report. Finally, cephalexin and cefuroxime are promising alternatives as initial treatment in postmenopausal women.

  5. Bile ductal injury and ductular reaction are frequent phenomena with different significance in autoimmune hepatitis.

    Science.gov (United States)

    Verdonk, Robert C; Lozano, Mallaki F; van den Berg, Aad P; Gouw, Annette S H

    2016-09-01

    The significance of bile duct injury and ductular reaction in biopsies from autoimmune hepatitis patients is not clear. We aim to establish the prevalence and clinical relevance of both phenomena in autoimmune hepatitis. Cases of newly diagnosed, untreated autoimmune hepatitis without overlap syndrome were selected. Pretreatment and follow up biopsies were scored for inflammation, fibrosis, bile ductal injury and ductular reaction. Thirty-five cases were studied of whom 14 cases had follow up biopsies. Bile duct injury was present in 29 cases (83%), mostly in a PBC-like pattern and was not correlated with demographical or laboratory findings. Ductular reaction, observed in 25 of 35 cases (71%) using conventional histology and in 30 of 32 cases (94%) using immunohistochemistry, was correlated with portal and lobular inflammation, interface hepatitis and centrilobular necrosis as well as bile duct injury and fibrosis. In 11 of 14 cases (79%) ductular reaction remained present on post-treatment biopsy whereas bile duct injury persisted in six of 14 (43%) of cases. Bile duct injury and ductular reaction are very common in newly diagnosed autoimmune hepatitis and cannot be predicted biochemically. Bile duct injury may subside in the majority of treated AIH cases while DR tends to persist during follow up. These findings show that the two phenomena are part of the spectrum of AIH with dissimilar responses to treatment and do not necessarily point towards an overlap syndrome. Persistence of ductular reaction after treatment supports the notion that it represents a regenerative response. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Different reasons for one significant choice: Factors influencing homeschooling choice in Israel

    Science.gov (United States)

    Guterman, Oz; Neuman, Ari

    2017-06-01

    Homeschooling is an alternative to conventional education in many countries all over the world, though legal regulations vary. This article examines why parents opt for homeschooling. The large body of research on the topic (especially from the United States) points to a variety of reasons for making the choice to homeschool. The most common reasons are of a pedagogical nature, but in many cases they are also family-related. What has not yet been investigated in depth is the relationship between the different reasons for choosing homeschooling and the way in which homeschooling is practised. There is also a lack of research on the relationship between the reasons for choosing homeschooling and the parents' personalities, educational background and attitudes towards both homeschooling in particular and the education system in general. Using a mixed methods design in order to examine these relationships, the authors of this article questioned 62 homeschooling families in Israel. The findings indicate that some parents chose to homeschool for pedagogical reasons only and others for both pedagogical and family-related reasons. Furthermore, the latter group held more positive views of the effect of homeschooling on children - and the mothers in that group, on average, were more educated compared with those who cited pedagogical reasons alone. The reasons for choosing homeschooling were also found to be associated with the character of the homeschooling practice, with families whose reasons were pedagogical only devoting more hours, on average, specifically to studying.

  7. Biomedical research in france and brazil: an analysis of significant differences and ethical issues

    Directory of Open Access Journals (Sweden)

    Hervé Moizan

    2016-06-01

    Full Text Available At first sight, Brazil and France seem pretty distant from one another, but on the map, they are not separated by the Atlantic Ocean, but by the Oyapock River, located between the state of Amapa and French Guiana (French overseas department, creating a 730 km long international border. If the distance does exist, it is very different when we finely analyze some similarities in the field of biomedical research. France is the biggest country of Western Europe and covers 1/5 of the European Union. Apart from Metropolitan France, the country contains overseas territories, remnants of its colonial past. Over the centuries, France has known several political systems, from Ancient History to the current Republic. According to Ernest Renan, the French nation is more an ideology than a reality, primarily based on “the desire of living together and the wish to highlight our legacy”(1. The tragic attacks of November 2015 and all the reactions over the next days illustrate this. Brazil, discovered by the Portuguese explorer Pedro Alvares during the 16th century, is established on half of South America and is about 16 times bigger than France. This giant does not look to the past but is always moving forward. The concept of nation is really strong throughout the country, as shown by the enthusiasm of soccer players wearing the national auriverde jersey and the National Team supporters. Furthermore, they possess a strong culture of entrepreneurship defined by Stefan Zweig as the legacy of the early colonial era(2. Biomedical research is a human activity which aims to give expected solutions, and sometimes unexpected ones too, to a major and insoluble problem at a given time. This research is based on knowledge and will question it with a scientific approach, spread between what is known today and what will be known tomorrow. Ideally, the point of getting new knowledge is to improve a group of people or the entire population’s health. The researcher is a

  8. Tautomeric transition between wobble A·C DNA base mispair and Watson-Crick-like A·C* mismatch: microstructural mechanism and biological significance.

    Science.gov (United States)

    Brovarets', Ol'ha O; Hovorun, Dmytro M

    2015-06-21

    Here, we use MP2/DFT quantum-chemical methods combined with Quantum Theory of Atoms in Molecules to study the tautomeric transition between wobble A·C(w) mismatch and Watson-Crick-like A·C*(WC) base mispair, proceeding non-dissociatively via sequential proton transfer between bases through the planar, highly stable and zwitterionic TS(A∙C-)(A∙C(W)A∙C&(WC)) transition state joined by the participation of (A)N6(+)H∙∙∙N4(-)(C), (A)N1(+)H∙∙∙N4(-)(C) and (A)C2(+)H∙∙∙N3(-)(C) H-bonds. Notably, the A·C(w) ↔ A·C*(WC) tautomerization reaction is accompanied by 10 unique patterns of the specific intermolecular interactions that consistently replace each other. Our data suggest that biologically significant A·C(w) → A·C*(WC) tautomerization is a kinetically controlled pathway for formation of the enzymatically competent Watson-Crick-like A·C*(WC) DNA base mispair in the essentially hydrophobic recognition pocket of the high-fidelity DNA-polymerase, responsible for the occurrence of spontaneous point AC/CA incorporation errors during DNA biosynthesis.

  9. Mechanical stress and stress release channels in 10–350 nm palladium hydrogen thin films with different micro-structures

    International Nuclear Information System (INIS)

    Wagner, Stefan; Kramer, Thilo; Uchida, Helmut; Dobron, Patrik; Cizek, Jakub; Pundt, Astrid

    2016-01-01

    For thin metal films adhered to rigid substrates hydrogen uptake results in compressive stresses in the GPa range. Stresses affect the thermodynamics as well as the durability of thin films, but many films can release stress above critical stress values. Depending on the films' thickness, microstructure and adhesion to the substrate, which determine the energy available in the nano-sized system, stress release is conducted via different release mechanisms. To evaluate the different mechanisms, Palladium thin films ranging from 10 nm to 350 nm and with three different types of microstructures (nanocrystalline, multi-oriented epitaxy and three-fold epitaxy) are studied with special focus on the mechanical stress. In-situ substrate curvature measurements, XRD stress analyses and acoustic emission (AE) measurements are conducted to determine intrinsic stresses, hydrogen-induced stress changes and stress release signals. By this complementary experimental approach, different stress release mechanisms (named channels) are identified. Discrete stress relaxation (DSR) events are found already within the overall linear elastic stress-strain regime. Energies to stimulate DSRs lay well below the formation energy of dislocations, and may allow the movement of defects pre-existing in the films. For higher strain energies, all studied films can release stress by the formation of new dislocations and plastic deformation. When the adhesion to the substrate is small, an alternative release channel of film buckling opens for thick films.

  10. Comparison of the thermal shock performance of different tungsten grades and the influence of microstructure on the damage behaviour

    International Nuclear Information System (INIS)

    Wirtz, M; Linke, J; Pintsuk, G; Singheiser, L; Uytdenhouwen, I

    2011-01-01

    The thermal shock performances of two new tungsten grades with 1 and 5 wt% of tantalum were characterized with the electron beam facility JUDITH 1. As a reference material, ultra-high-purity tungsten (W-UHP) with a purity of 99.9999 wt% was used. The induced thermal shock crack networks and surface modifications were analysed by a scanning electron microscope, light microscopy and laser profilometry. Damage and cracking thresholds were defined for all materials as a function of absorbed power density and base temperature. The materials showed significantly different thermal shock behaviour, which is, among others, expressed by differences in cracking patterns, i.e. crack distance and depth. These results allow us to quantify the influence of the materials' mechanical and thermal properties on the thermal shock performance. Furthermore, the specific grain structure of the materials has a significant influence on crack propagation towards the bulk material.

  11. Non-invasive prediction of hemodynamically significant coronary artery stenoses by contrast density difference in coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Hell, Michaela M., E-mail: michaela.hell@uk-erlangen.de [Department of Cardiology, University of Erlangen (Germany); Dey, Damini [Department of Biomedical Sciences, Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Taper Building, Room A238, 8700 Beverly Boulevard, Los Angeles, CA 90048 (United States); Marwan, Mohamed; Achenbach, Stephan; Schmid, Jasmin; Schuhbaeck, Annika [Department of Cardiology, University of Erlangen (Germany)

    2015-08-15

    Highlights: • Overestimation of coronary lesions by coronary computed tomography angiography and subsequent unnecessary invasive coronary angiography and revascularization is a concern. • Differences in plaque characteristics and contrast density difference between hemodynamically significant and non-significant stenoses, as defined by invasive fractional flow reserve, were assessed. • At a threshold of ≥24%, contrast density difference predicted hemodynamically significant lesions with a specificity of 75%, sensitivity of 33%, PPV of 35% and NPV of 73%. • The determination of contrast density difference required less time than transluminal attenuation gradient measurement. - Abstract: Objectives: Coronary computed tomography angiography (CTA) allows the detection of obstructive coronary artery disease. However, its ability to predict the hemodynamic significance of stenoses is limited. We assessed differences in plaque characteristics and contrast density difference between hemodynamically significant and non-significant stenoses, as defined by invasive fractional flow reserve (FFR). Methods: Lesion characteristics of 59 consecutive patients (72 lesions) in whom invasive FFR was performed in at least one coronary artery with moderate to high-grade stenoses in coronary CTA were evaluated by two experienced readers. Coronary CTA data sets were acquired on a second-generation dual-source CT scanner using retrospectively ECG-gated spiral acquisition or prospectively ECG-triggered axial acquisition mode. Plaque volume and composition (non-calcified, calcified), remodeling index as well as contrast density difference (defined as the percentage decline in luminal CT attenuation/cross-sectional area over the lesion) were assessed using a semi-automatic software tool (Autoplaq). Additionally, the transluminal attenuation gradient (defined as the linear regression coefficient between intraluminal CT attenuation and length from the ostium) was determined

  12. Microstructure and Hardness of Mg - 9Li - 6Al Alloy After Different Variants of Solid Solution Treatment

    Science.gov (United States)

    Zheng, Haipeng; Fei, Pengfei; Wu, Ruizhi; Hou, Legan; Zhang, Milin

    2018-03-01

    The microstructure and the hardness of cast magnesium alloy Mg - 9% Li - 6% Al are studied after a treatment for solid solution at 300, 350, and 450°C for 0.5 - 5 h. The phase composition of the alloy is represented by α-Mg, β-Li, thin-plate and faceted particles of an AlLi phase, and particles of a MgLi2Al θ-phase. The θ-phase dissolves in the matrix in the initial stage of the solution treatment, which causes growth in the hardness of the alloy. At a temperature above 350°C the AlLi phase dissolves giving way to short rod-like precipitates of a θ-phase, which remain steady in the process of solution treatment. The hardness of the alloy deceases in this stage for this reason.

  13. Comparison of different drying methods on Chinese ginger (Zingiber officinale Roscoe): Changes in volatiles, chemical profile, antioxidant properties, and microstructure.

    Science.gov (United States)

    An, Kejing; Zhao, Dandan; Wang, Zhengfu; Wu, Jijun; Xu, Yujuan; Xiao, Gengsheng

    2016-04-15

    Nowadays, food industry is facing challenges in preserving better quality of fruit and vegetable products after processing. Recently, many attentions have been drawn to ginger rhizome processing due to its numerous health promoting properties. In our study, ginger rhizome slices were subjected to air-drying (AD), freeze drying (FD), infrared drying (IR), microwave drying (MD) and intermittent microwave & convective drying (IM&CD). Quality attributes of the dried samples were compared in terms of volatile compounds, 6, 8, 10-gingerols, 6-shogaol, antioxidant activities and microstructure. Results showed that AD and IR were good drying methods to preserve volatiles. FD, IR and IM&CD led to higher retention of gingerols, TPC, TFC and better antioxidant activities. However, FD and IR had relative high energy consumption and drying time. Therefore, considering about the quality retention and energy consumption, IM&CD would be very promising for thermo sensitive material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. TIG AISI-316 welds using an inert gas welding chamber and different filler metals: Changes in mechanical properties and microstructure

    Directory of Open Access Journals (Sweden)

    Sánchez, A.

    2010-12-01

    Full Text Available This report analyses the influence of the use of an inert gas welding chamber with a totally inert atmosphere on the microstructure and mechanical properties of austenitic AISI 316L stainless steel TIG welds, using AISI ER316L, AISI 308L and Inconel 625 as filler metals. When compared with the typical TIG process, the use of the inert gas chamber induced changes in the microstructure, mainly an increase in the presence of vermicular ferrite and ferrite stringers, what resulted in higher yield strengths and lower values of hardness. Its effect on other characteristics of the joins, such as tensile strength, depended on the filler metal. The best combination of mechanical characteristics was obtained when welding in the inert gas chamber using Inconel 625 as filler metal.

    En este estudio se analiza la influencia que el uso de una cámara de soldadura de gas inerte tiene sobre la microestructura y las propiedades mecánicas de las soldaduras TIG en el acero inoxidable austenítico AISI-316L cuando se emplean AISI ER316L, AISI 308L e Inconel 625 como materiales de aporte. Cuando se compara con el típico proceso de TIG, el uso de una cámara de gas inerte induce cambios en la microestructura, incrementando la presencia de ferrita vermicular y de laminillas de ferrita, resultando en un aumento del límite elástico y una pérdida de dureza. Su influencia sobre otras características de las soldaduras como la carga de rotura depende de la composición del material de aporte. La mejor combinación de propiedades mecánicas se obtuvo usando el Inconel 625 como material de aporte y soldando en la cámara de gas inerte.

  15. Microstructure of irradiated materials

    International Nuclear Information System (INIS)

    Robertson, I.M.

    1995-01-01

    The focus of the symposium was on the changes produced in the microstructure of metals, ceramics, and semiconductors by irradiation with energetic particles. the symposium brought together those working in the different material systems, which revealed that there are a remarkable number of similarities in the irradiation-produced microstructures in the different classes of materials. Experimental, computational and theoretical contributions were intermixed in all of the sessions. This provided an opportunity for these groups, which should interact, to do so. Separate abstracts were prepared for 58 papers in this book

  16. Microstructural, Mechanical, and Electrochemical Analysis of Duplex and Superduplex Stainless Steels Welded with the Autogenous TIG Process Using Different Heat Input

    Directory of Open Access Journals (Sweden)

    Gláucio Soares da Fonseca

    2017-12-01

    Full Text Available Duplex Stainless Steels (DSS and Superduplex Stainless Steels (SDSS have a strong appeal in the petrochemical industry. These steels have excellent properties, such as corrosion resistance and good toughness besides good weldability. Welding techniques take into account the loss of alloying elements during the process, so this loss is usually compensated by the addition of a filler metal rich in alloying elements. A possible problem would be during the welding of these materials in adverse conditions in service, where the operator could have difficulties in welding with the filler metal. Therefore, in this work, two DSS and one SDSS were welded, by autogenous Tungsten Inert Gas (TIG, i.e., without addition of a filler metal, by three different heat inputs. After welding, microstructural, mechanical, and electrochemical analysis was performed. The microstructures were characterized for each welding condition, with the aid of optical microscopy (OM. Vickers hardness, Charpy-V, and cyclic polarization tests were also performed. After the electrochemical tests, the samples were analyzed by scanning electron microscopy (SEM. The SDSS welded with high heat input kept the balance of the austenite and ferrite, and toughness above the limit value. The hardness values remain constant in the weld regions and SDSS is the most resistant to corrosion.

  17. Significant difference in p53 and p21 protein immunoreactivity in HPV 16 positive and HPV negative breast carcinomas

    International Nuclear Information System (INIS)

    Hennig, E.M.; Norwegian Radium Hospital, Oslo; Kvinnsland, S.; Holm, R.; Nesland, J.M.

    1999-01-01

    Human papillomavirus (HPV) 16 has previously been found in 19/41 breast carcinomas (46%) in women with a history of HPV 16 positive CIN III lesions. There was no significant difference in distribution of histological subtypes, mean or median tumour diameter or number of regional lymph node metastases in the HPV positive and HPV negative breast carcinoma groups. P53, p21 and c-erbB-2 proteins were analyzed by immunohistochemistry in the HPV 16 positive and HPV negative breast carcinomas. There was a significant difference in p53 and p21 protein immunoreactivity between HPV 16 positive and HPV negative breast carcinomas (p=0.0091 and p=0.0040), with a significant less detectable p53 and p21 protein immunoreactivity in the HPV 16 positive cases. There was also a significant difference in the coexpression of p53/p21 between the HPV 16 positive and HPV 16 negative breast carcinomas (p=0.002). No significant difference in immunostaining for c-erbB-2 protein in the two groups was found (p=0.15), or for the coexpression of p53/c-erbB-2 (p=0.19). The significantly lower expression of p53 and p21 proteins in HPV 16 positive than in HPV 16 negative breast carcinomas supports the hypothesis of inactivation and degradation of wild-type p53 proteins by HPV 16 E6 and that p53 mutation is not necessary for transformation in the HPV 16 positive cases. (orig.)

  18. Microstructure taxonomy based on spatial correlations: Application to microstructure coarsening

    International Nuclear Information System (INIS)

    Fast, Tony; Wodo, Olga; Ganapathysubramanian, Baskar; Kalidindi, Surya R.

    2016-01-01

    To build materials knowledge, rigorous description of the material structure and associated tools to explore and exploit information encoded in the structure are needed. These enable recognition, categorization and identification of different classes of microstructure and ultimately enable to link structure with properties of materials. Particular interest lies in the protocols capable of mining the essential information in large microstructure datasets and building robust knowledge systems that can be easily accessed, searched, and shared by the broader materials community. In this paper, we develop a protocol based on automated tools to classify microstructure taxonomies in the context of coarsening behavior which is important for long term stability of materials. Our new concepts for enhanced description of the local microstructure state provide flexibility of description. The mathematical description of microstructure that capture crucial attributes of the material, although central to building materials knowledge, is still elusive. The new description captures important higher order spatial information, but at the same time, allows down sampling if less information is needed. We showcase the classification protocol by studying coarsening of binary polymer blends and classifying steady state structures. We study several microstructure descriptions by changing the microstructure local state order and discretization and critically evaluate their efficacy. Our analysis revealed the superior properties of microstructure representation is based on the first order-gradient of the atomic fraction.

  19. 3-D observations of short fatigue crack interaction with la2mellar and duplex microstructures in a two-phase titanium alloy

    International Nuclear Information System (INIS)

    Birosca, S.; Buffiere, J.Y.; Karadge, M.; Preuss, M.

    2011-01-01

    In situ observations of short crack growth in powder-processed Ti-6246 have been undertaken using synchrotron X-ray microtomography to investigate crack tip interaction with microstructure. Together with post-mortem analysis using electron backscatter diffraction (EBSD), it was possible to identify a number of microstructural features that affect crack propagation rates by causing crack bifurcation, crack bridging and crack deflection. Three samples with different microstructures were tested in this way: lamellar, duplex and a heterogeneous microstructure that showed regions of lamellar and duplex microstructure. The in situ fatigue experiments were carried out with a maximum stress of 410 MPa and R = 0.1. The three microstructures showed significantly different short crack propagation rates, with the lamellar microstructure displaying the fastest and the duplex microstructure the slowest rate. It was found that the lamellar microstructure develops a deeper crack than the duplex microstructure that is related to significant crack bifurcation taking place near the surface region in the lamellar but not duplex microstructure. It was also found that a columnar lamellar microstructure creates a relatively smooth crack front while a basket-weave-type microstructure forces the crack tip to undulate on the lath width scale. Crack bridging of the fine lamellar region of the duplex microstructure was observed, which seems to hinder significant crack bifurcation to occur, but still provides improved crack growth resistance that explains the low crack propagation rate. In the third microstructure the crack tended to grow slightly asymmetrically due to the heterogeneous nature of the microstructure, resulting in the intermediate growth rate. EBSD grain orientation and Schmid factor analysis of regions including the crack revealed that the crack path is strongly influenced by the crystallographic orientation of the α lamellae and grains. While in the lamellar microstructure

  20. Illness perceptions in the context of differing work participation outcomes: exploring the influence of significant others in persistent back pain

    Directory of Open Access Journals (Sweden)

    Brooks Joanna

    2013-01-01

    Full Text Available Abstract Background Previous research has demonstrated that the significant others of individuals with persistent back pain may have important influences on work participation outcomes. The aim of this study was to extend previous research by including individuals who have remained in work despite persistent back pain in addition to those who had become incapacitated for work, along with their significant others. The purpose of this research was to explore whether the illness beliefs of significant others differed depending on their relative’s working status, and to make some preliminary identification of how significant others may facilitate or hinder work participation for those with persistent back pain. Methods Interviews structured around the Illness Perception Questionnaire (chronic pain version were conducted with back pain patients recruited from a hospital pain management clinic along with their significant others. Some patients had remained in work despite their back pain; others had ceased employment. Data were analysed using template analysis. Results There were clear differences between beliefs about, and reported responses to, back pain symptoms amongst the significant others of individuals who had remained in employment compared with the significant others of those who had ceased work. Three overarching themes emerged: perceived consequences of back pain, specific nature of employment and the impact of back pain on patient identity. Conclusions Significant others of employed individuals with back pain focused on the extent to which activity could still be undertaken despite back pain symptoms. Individuals out of work due to persistent back pain apparently self-limited their activity and were supported in their beliefs and behaviours by their significant others. To justify incapacity due to back pain, this group had seemingly become entrenched in a position whereby it was crucial that the individual with back pain was perceived

  1. Fabrication and characterization of a hybrid four-hole AsSe₂-As₂S₅ microstructured optical fiber with a large refractive index difference.

    Science.gov (United States)

    Cheng, Tonglei; Kanou, Yasuhire; Deng, Dinghuan; Xue, Xiaojie; Matsumoto, Morio; Misumi, Takashi; Suzuki, Takenobu; Ohishi, Yasutake

    2014-06-02

    A hybrid four-hole AsSe2-As2S5 microstructured optical fiber (MOF) with a large refractive index difference is fabricated by the rod-in-tube drawing technique. The core and the cladding are made from the AsSe2 glass and As2S5 glass, respectively. The propagation loss is ~1.8 dB/m and the nonlinear coefficient is ~2.03 × 10(4) km(-1)W(-1) at 2000 nm. Raman scattering is observed in the normal dispersion regime when the fiber is pumped by a 2 μm mode-locked picosecond fiber laser. Additionally, soliton is generated in the anomalous dispersion regime when the fiber is pumped by an optical parametric oscillator (OPO) at the pump wavelength of ~3000 nm.

  2. Evolution of the microstructure and hardness of a rapidly solidified/melt-spun AZ91 alloy upon aging at different temperatures

    International Nuclear Information System (INIS)

    Wang Baishu; Liu Yongbing; An Jian; Li Rongguang; Su Zhenguo; Su Guihua; Lu You; Cao Zhanyi

    2009-01-01

    The effect of aging at different temperatures on a rapidly solidified/melt-spun AZ91 alloy has been investigated in depth. The microstructures of as-spun and aged ribbons with a thickness of approximately 60 μm were characterized using X-ray diffraction, transmission electron microscopy and laser optical microscopy; microhardness measurements were also conducted. It was found that the commercial AZ91 alloy undergoes a cellular/dendritic transition during melt-spinning at a speed of 34 m/s. A strengthening effect due to aging was observed: a maximum hardness of 110 HV/0.05 and an age-hardenability of 50% were obtained when the ribbon was aged at 200 deg. C for 20 min. The β-Mg 17 Al 12 phase exhibits net and dispersion types of distribution during precipitation. The dispersion of precipitates in dendritic grains or cells is the main source of strengthening

  3. Human papillomavirus detection with genotyping by the cobas and Aptima assays: Significant differences in HPV 16 detection?

    Science.gov (United States)

    Chorny, Joseph A; Frye, Teresa C; Fisher, Beth L; Remmers, Carol L

    2018-03-23

    The primary high-risk human papillomavirus (hrHPV) assays in the United States are the cobas (Roche) and the Aptima (Hologic). The cobas assay detects hrHPV by DNA analysis while the Aptima detects messenger RNA (mRNA) oncogenic transcripts. As the Aptima assay identifies oncogenic expression, it should have a lower rate of hrHPV and genotype detection. The Kaiser Permanente Regional Reference Laboratory in Denver, Colorado changed its hrHPV assay from the cobas to the Aptima assay. The rates of hrHPV detection and genotyping were compared over successive six-month periods. The overall hrHPV detection rates by the two platforms were similar (9.5% versus 9.1%) and not statistically different. For genotyping, the HPV 16 rate by the cobas was 1.6% and by the Aptima it was 1.1%. These differences were statistically different with the Aptima detecting nearly one-third less HPV 16 infections. With the HPV 18 and HPV 18/45, there was a slightly higher detection rate of HPV 18/45 by the Aptima platform (0.5% versus 0.9%) and this was statistically significant. While HPV 16 represents a low percentage of hrHPV infections, it was detected significantly less by the Aptima assay compared to the cobas assay. This has been previously reported, although not highlighted. Given the test methodologies, one would expect the Aptima to detect less HPV 16. This difference appears to be mainly due to a significantly increased number of non-oncogenic HPV 16 infections detected by the cobas test as there were no differences in HPV 16 detection rates in the high-grade squamous intraepithelial lesions indicating that the two tests have similar sensitivities for oncogenic HPV 16. © 2018 Wiley Periodicals, Inc.

  4. Significant factors for work attractiveness and how these differ from the current work situation among operating department nurses.

    Science.gov (United States)

    Björn, Catrine; Lindberg, Magnus; Rissén, Dag

    2016-01-01

    The aim was to examine significant factors for work attractiveness and how these differ from the current work situation among operating department nurses. A second objective was to examine the associations between age, gender, length of employment, work engagement, work ability, self-rated health indicators and attractiveness of the current work situation. The attractiveness of work is rarely taken into account in research on nurse retention. To expand this knowledge, it is relevant to examine factors that make work attractive and their associations with related concepts. Correlational, cross-sectional survey using a convenience sample. Questionnaires were answered by 147 nurses in four operating departments in Sweden. Correlation and regression analyses were conducted. The nurses rated the significance of all factors of work attractiveness higher than they rated those factors in their current work situation; salary, organisation and physical work environment had the largest differences. The most significant attractive factors were relationships, leadership and status. A statistically significant positive correlation between work engagement and attractive work was found. In the multiple regression model, the independent variables work engagement and older age significantly predicted work attractiveness. Several factors should be considered in the effort to increase work attractiveness in operating departments and thereby to encourage nurse retention. Positive aspects of work seem to unite work engagement and attractive work, while work ability and self-rated health indicators are other important dimensions in nurse retention. The great discrepancies between the significance of attractive factors and the current work situation in salary, organisation and physical work environment suggest ways in which work attractiveness may be increased. To discover exactly what needs to be improved may require a deeper look into the construct of the examined factors. © 2015 John

  5. Microstructure and properties of the low-power-laser clad coatings on magnesium alloy with different amount of rare earth addition

    International Nuclear Information System (INIS)

    Zhu, Rundong; Li, Zhiyong; Li, Xiaoxi; Sun, Qi

    2015-01-01

    Highlights: • The low-power-laser was used to obtain the excellent coatings with different amount of Y_2O_3 addition. • The addition of rare earth oxide Y_2O_3 refined and purified the microstructure of the coatings, meanwhile, increased the thickness of the coatings and reduced the dilution of cladding materials from based alloy. • The primary phases in the coatings are Mg_3_2Al_4_7Cu_7, MgCu_6Al_5, Al_2CuMg and Al_1_2Mg_1_7. The A_l_4MgY and MgAl_2O_4 phase can be found in Y_2O_3-modified coatings. • The micro-hardness and the abrasion resistance of the coatings with Y_2O_3 had been improved obviously compared with the coatings without Y_2O_3. • The corrosion resistance of the AZ91D magnesium alloy had been improved by laser cladding. And the effect of Y_2O_3 on the corrosion potential of the coatings was less than the effect of Y_2O_3 on corrosion current density of the coatings. - Abstract: Due to the low-melting-point and high evaporation rate of magnesium at elevated temperature, high power laser clad coating on magnesium always causes subsidence and deterioration in the surface. Low power laser can reduce the evaporation effect while brings problems such as decreased thickness, incomplete fusion and unsatisfied performance. Therefore, low power laser with selected parameters was used in our research work to obtain Al–Cu coatings with Y_2O_3 addition on AZ91D magnesium alloy. The addition of Y_2O_3 obviously increases thickness of the coating and improves the melting efficiency. Furthermore, the effect of Y_2O_3 addition on the microstructure of laser clad Al–Cu coatings was investigated by scanning electron microscopy. The energy-dispersive spectrometer (EDS) and X-ray diffractometer (XRD) were used to examine the elemental and phase compositions of the coatings. The properties were investigated by micro-hardness test, dry wear test and electrochemical corrosion. It was found that the addition of Y_2O_3 refined the microstructure. The micro

  6. [The expression and significance of VIP and its receptor in the cochlea of different degrees of chronic alcoholism rats].

    Science.gov (United States)

    Feng, Jing; Liu, Haibing

    2015-07-01

    To determine whether chronic alcoholism alters the expression levels of Vasoactive intestinal polypeptide (VIP) and its receptor (VIPR1) in the cochlea of chronic alcoholism rats. We measured their expression levels in 30 SD rats, in which we created models of different degrees of chronic alcoholism. We investigated the presence of the mRNA of VIP in the cochlea of chronic alcoholism rats and controls by reverse transcription-polymerase chain reaction (RT-PCR) method. We investigated the presence of proteins of VIPR1 in poisoned rats and controls by western blot. We also evaluated the local distribution of VIP cells by immunohistochemistry. We found that the levels of VIP and VIPR1 were downregulated in the chronic alcoholism groups compared to the controls group. The differences in some expression levels were significant different between chronic alcoholism rats and control rats. Moreover, at different degrees of alcohol poisoning in rats, the contents of VIP and VIPR1 differed. Decreased levels of VIP and VIPR1 were detected in the deep chronic alcoholism group compared to the group with low-degree poisoning (P 0.05). These results suggest that VIP and VIPR1 play an important role in the auditory function in rats with chronic alcoholism. Chronic alcoholism may cause a peptide hormone secretion imbalance in the auditory system, eventually leading to hearing loss.

  7. Commonly used bowel preparations have significant and different effects upon cell proliferation in the colon: a pilot study

    Directory of Open Access Journals (Sweden)

    Riley Stuart A

    2008-11-01

    Full Text Available Abstract Background Markers of crypt cell proliferation are frequently employed in studies of the impact of genetic and exogenous factors on human colonic physiology. Human studies often rely on the assessment of tissue acquired at endoscopy. Modulation of cell proliferation by bowel preparation with oral laxatives may confound the findings of such studies, but there is little data on the impact of commonly used bowel preparations on markers of cell proliferation. Methods Crypt length, crypt cellularity and crypt cell proliferation were assessed in biopsies acquired after preparation with either Klean-Prep or Picolax. Crypt cell proliferation was assessed by whole-mount mitotic figure count, and by two different immunohistochemical (IHC labelling methods (Ki-67 and pHH3. Subsequent biopsies were obtained from the same patients without bowel preparation and similarly assessed. Parameters were compared between groups using analysis of variance and paired t-tests. Results There were significant differences in labelling indices (LI between biopsies taken after Klean-prep and those taken after Picolax preparation, for both Ki67 (p = 0.019 and pHH3 (p = 0.017. A similar trend was seen for whole-mount mitotic figure counts. Suppression or elevation of proliferation parameters by bowel preparation may mask any effect due to an intervention or disease. Conclusion Commonly used bowel preparations may have significant and different effects on crypt cell proliferation. This should be taken into account when designing studies and when considering the findings of existing studies.

  8. Variations in the microstructure and properties of Mn-Ti multiple-phase steel with high strength under different tempering temperatures

    Science.gov (United States)

    Li, Dazhao; Li, Xiaonan; Cui, Tianxie; Li, Jianmin; Wang, Yutian; Fu, Peimao

    2015-03-01

    There are few relevant researches on coils by tempering, and the variations of microstructure and properties of steel coil during the tempering process also remain unclear. By using thermo-mechanical control process(TMCP) technology, Mn-Ti typical HSLA steel coils with yield strength of 920 MPa are produced on the 2250 hot rolling production line. Then, the samples are taken from the coils and tempered at the temperatures of 220 °C, 350 °C, and 620 °C respectively. After tempering the strength, ductility and toughness of samples are tested, and meanwhile microstructures are investigated. Precipitates initially emerge inside the ferrite laths and the density of the dislocation drops. Then, the lath-shaped ferrites begin to gather, and the retained austenite films start to decompose. Finally, the retained austenite films are completely decomposed into coarse and short rod-shape precipitates composed of C and Ti compounds. The yield strength increases with increasing tempering temperature due to the pinning effect of the precipitates, and the dislocation density decreases. The yield strength is highest when the steel is tempered at 220 °C because of pinning of the precipitates to dislocations. The total elongation increases in all samples because of the development of ferrites during tempering. The tensile strength and impact absorbed energy decline because the effect of impeding crack propagation weakens as the retained austenite films completely decompose and the precipitates coarsen. This paper clarifies the influence of different tempering temperatures on phase transformation characteristics and process of Mn-Ti typical multiphase steels, as well as its resulting performance variation rules.

  9. In vitro cell culture pO2 is significantly different from incubator pO2.

    Science.gov (United States)

    Bambrick, L L; Kostov, Y; Rao, G

    2011-07-01

    Continuous noninvasive monitoring of peri-cellular liquid phase pO2 in adherent cultures is described. For neurons and astrocytes, this approach demonstrates that there is a significant difference between predicted and observed liquid phase pO2. Particularly at low gas phase pO2s, cell metabolism shifts liquid phase pO2 significantly lower than would be predicted from the O2 gas/air equilibrium coefficient, indicating that the cellular oxygen uptake rate exceeds the oxygen diffusion rate. The results demonstrate the need for direct pO2 measurements at the peri-cellular level, and question the widely adopted current practice of relying on setting the incubator gas phase level as means of controlling pericellular oxygen tension, particularly in static culture systems that are oxygen mass transfer limited. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

  10. Expression and significance of MMP3 in synovium of knee joint at different stage in osteoarthritis patients.

    Science.gov (United States)

    Chen, Jun-Jie; Huang, Jie-Feng; Du, Wen-Xi; Tong, Pei-Jian

    2014-04-01

    To investigate the expression and significance of MMP-3 in synovium of knee joint at different stage in osteoarthritis (OA) patients. Knee synovial tissue were collected in 90 OA patients (the OA group). Patients in the OA group was divided into 3 subgroups: grade I subgroup (n=30), grade II subgroup (n=30), grade III; subgroup (n=30). Thirty patients served as control group. Immunohistochemical assay was used to detect the expression of MMP-3 protein in the knee synovial tissue. MMP-3 protein was detected in all knee synovial tissue. The expression of MMP-3 protein in the OA group was significantly higher that in the normal synovium (Posteoarthritis. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  11. Superfund explanation of significant difference for the record of decision (EPA Region 8): Lowry Landfill, Aurora, CO, October 24, 1997

    International Nuclear Information System (INIS)

    1999-03-01

    Please be advised that there is an error within Attachment E (Technical Evaluation of Proposed Ground-Water Treatment and Disposal Alternatives) of the ''Responsiveness Summary for the Second Explanation of Significant Differences, Lowry Landfill Superfund Site'' document. The evaluation table, which summarizes the rankings of the two cleanup alternatives, failed to include numerical values for State Acceptance and Community Acceptance. Enclosed is a copy of the table as it should have appeared in Attachment E. Copies of this errata sheet are being mailed to all recipients of the Responsiveness Summary

  12. Global genomic analysis of intraductal papillary mucinous neoplasms of the pancreas reveals significant molecular differences compared to ductal adenocarcinoma.

    Science.gov (United States)

    Fritz, Stefan; Fernandez-del Castillo, Carlos; Mino-Kenudson, Mari; Crippa, Stefano; Deshpande, Vikram; Lauwers, Gregory Y; Warshaw, Andrew L; Thayer, Sarah P; Iafrate, A John

    2009-03-01

    To determine whether intraductal papillary mucinous neoplasms of the pancreas (IPMNs) have a different genetic background compared with ductal adenocarcinoma (PDAC). The biologic and clinical behavior of IPMNs and IPMN-associated adenocarcinomas is different from PDAC in having a less aggressive tumor growth and significantly improved survival. Up to date, the molecular mechanisms underlying the clinical behavior of IPMNs are incompletely understood. 128 cystic pancreatic lesions were prospectively identified during the course of 2 years. From the corresponding surgical specimens, 57 IPMNs were separated and subdivided by histologic criteria into those with low-grade dysplasia, moderate dysplasia, high-grade dysplasia, and invasive cancer. Twenty specimens were suitable for DNA isolation and subsequent performance of array CGH. While none of the IPMNs with low-grade dysplasia displayed detectable chromosomal aberrations, IPMNs with moderate and high-grade dysplasia showed frequent copy number alterations. Commonly lost regions were located on chromosome 5q, 6q, 10q, 11q, 13q, 18q, and 22q. The incidence of loss of chromosome 5q, 6q, and 11q was significantly higher in IPMNs with high-grade dysplasia or invasion compared with PDAC. Ten of 13 IPMNs with moderate dysplasia or malignancy had loss of part or all of chromosome 6q, with a minimal deleted region between linear positions 78.0 and 130.0. This study is the first to use array CGH to characterize IPMNs. Recurrent cytogenetic alterations were identified and were different than those described in PDAC. Array CGH may help distinguish between these 2 entities and give insight into the differences in their biology and prognosis.

  13. Full investigation of patients with polycystic ovary syndrome (PCOS) presenting to four different clinical specialties reveals significant differences and undiagnosed morbidity.

    Science.gov (United States)

    Sivayoganathan, Dhakshana; Maruthini, Deivanayagam; Glanville, Julie M; Balen, Adam H

    2011-12-01

    This study aimed to compare the spectrum of polycystic ovary syndrome (PCOS) symptoms in patients from four different specialist clinics. A prospective cross-sectional observational study. The study was conducted at the infertility, gynaecology, endocrine and dermatology clinics at Leeds General Infirmary, U.K. Seventy women presenting with features of PCOS: 20 from infertility, 17 from gynaecology, 17 from dermatology and 16 from endocrine clinics. Participants were assessed for symptoms and signs of PCOS and underwent a full endocrine and metabolic profile and a pelvic ultrasound scan. All subjects had experienced menstrual problems, 81% were overweight, 86% had polycystic ovaries on ultrasound, 56% had hirsutism, 53% had acne, 23% had acanthosis nigricans, 16% had alopecia and 38% had previously undiagnosed impaired glucose tolerance (IGT) or diabetes. A significant difference between the four clinic groups existed with regard to menstrual patterns (p = 0.0234), frequency distribution of presenting symptoms and the percentages of patients with PCOS who had already been diagnosed as having PCOS (p = 0.0088). This study emphasizes the importance of understanding the full spectrum of PCOS as presented to different specialty clinics. Not only is the syndrome under diagnosed but also are the significant associated morbidities such as IGT and type 2 diabetes. Different specialists need to appreciate the spectrum of health problems for women with PCOS that may extend beyond the specific symptoms that precipitated the initial referral.

  14. THE PROGNOSIS SIGNIFICANCE OF CATHEPSIN-D EXPRESSION IN THE DIFFERENT LOCATIONS IN AXILLARY NODES NEGATIVE CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: The aim of this study was to investigate Cathepsin-D (Cath-D) expression in different location and its relationship with prognosis in the axillary lymph nodes negative (ANN) breast cancer patients. Methods: Cath-D expression in 192 cases of breast carcinoma were examined by immunohistochemistry. Depending on different parts of expression, three evaluating methods were used, compared and analysed. Results: The positive rate of Cath-D expression in ANN breast cancer with poor prognosis group and axillary nodes positive (ANP) group were significantly higher than that in ANN breast cancer with good prognosis group (x2=23.20, P0.05). Cath-D expression in stromal cells had no statistical difference among the three groups (x2=1.56, P>0.05). When the Cath-D expression in cancer and stromal cells were counted into the positive rate, it was near the same (u1=0.47, u2=1.41, P>0.05). Conclusion: These results suggest that Cath-D expression is one of the powerful prognostic markers in ANN breast cancer. It's a reliable, practical, and convenient method to observe and evaluate Cath-D expression in cancer cells.

  15. Effect of Phenomena Accompanying Wear in Dry Corundum Abrasive on the Properties and Microstructure of Austempered Ductile Iron with Different Chemical Composition

    Directory of Open Access Journals (Sweden)

    Myszka D.

    2015-04-01

    Full Text Available The research described in this article is a fragment in the series of published works trying to determine the applicability of new materials for parts of the mining machinery. Tests were performed on two groups of austempered ductile iron - one of which contained 1.5% Ni and 0.5% Mo, while the other contained 1.9% Ni and 0.9% Cu. Each group has been heat treated according to the three different heat treatment variants and then the material was subjected to detailed testing of mechanical properties and abrasion wear resistance, measuring also hardness and magnetic properties, and conducting microstructural examinations. The results indicated that each of the tested materials was senstive to the surface hardening effect, which resulted in high wear resistance. It has been found that high temperature of austempering, i.e. 370°C, favours high wear resistance of ductile iron containing nickel and molybdenum. Low temperature of austempering, i.e. 270°C, develops high wear resistance in ductile iron containing nickel and copper. Both these materials offer completely different mechanical properties and as such can be used for different and specific applications.

  16. Microstructural and magnetic properties of L10 FePt-C (0 0 1) textured nanocomposite films grown on different intermediate layers

    International Nuclear Information System (INIS)

    Chen, J S; Chow, G M; Lim, B C; Hu, J F; Ding, Y F; Ju, G

    2008-01-01

    The FePt : C films with different volume fractions of carbon and different thicknesses were epitaxially grown on a CrRu(2 0 0) underlayer with Pt and MgO intermediate layers. The magnetic properties and microstructure of these FePt : C films were investigated. The FePt : C films grown on the Pt intermediate layer consisted of a continuous layer of FePt, with overlying granular FePt grains, while the FePt : C films grown on the MgO intermediate layer consisted of granular FePt : C layers with overlying granular grains. The formation of the overlying granular FePt grains was attributed to carbon diffusion to the surface which resulted in the second nucleation of FePt. The different interface energies and surface energies of FePt on Pt and MgO intermediate layers caused the formation of an initial continuous FePt layer on the Pt intermediate layer and initial granular FePt layers on the MgO intermediate layer. The coupling between the continuous FePt layer or the granular FePt layer and the overlying granular FePt grains resulted in simultaneous magnetization reversal and thus strong exchange coupling in FePt : C films.

  17. DIFFERENCES IN WATER VAPOR RADIATIVE TRANSFER AMONG 1D MODELS CAN SIGNIFICANTLY AFFECT THE INNER EDGE OF THE HABITABLE ZONE

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jun; Wang, Yuwei [Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing (China); Leconte, Jérémy; Forget, François [Laboratoire de Météorologie Dynamique, Institut Pierre Simon Laplace, CNRS, Paris (France); Wolf, Eric T. [Laboratory for Atmospheric and Space Physics, University of Colorado in Boulder, CO (United States); Goldblatt, Colin [School of Earth and Ocean Sciences, University of Victoria, Victoria, BC (Canada); Feldl, Nicole [Division of Geological and Planetary Sciences, California Institute of Technology, CA (United States); Merlis, Timothy [Department of Atmospheric and Oceanic Sciences at McGill University, Montréal (Canada); Koll, Daniel D. B.; Ding, Feng; Abbot, Dorian S., E-mail: junyang@pku.edu.cn, E-mail: abbot@uchicago.edu [Department of the Geophysical Sciences, University of Chicago, Chicago, IL (United States)

    2016-08-01

    An accurate estimate of the inner edge of the habitable zone is critical for determining which exoplanets are potentially habitable and for designing future telescopes to observe them. Here, we explore differences in estimating the inner edge among seven one-dimensional radiative transfer models: two line-by-line codes (SMART and LBLRTM) as well as five band codes (CAM3, CAM4-Wolf, LMDG, SBDART, and AM2) that are currently being used in global climate models. We compare radiative fluxes and spectra in clear-sky conditions around G and M stars, with fixed moist adiabatic profiles for surface temperatures from 250 to 360 K. We find that divergences among the models arise mainly from large uncertainties in water vapor absorption in the window region (10 μ m) and in the region between 0.2 and 1.5 μ m. Differences in outgoing longwave radiation increase with surface temperature and reach 10–20 W m{sup 2}; differences in shortwave reach up to 60 W m{sup 2}, especially at the surface and in the troposphere, and are larger for an M-dwarf spectrum than a solar spectrum. Differences between the two line-by-line models are significant, although smaller than among the band models. Our results imply that the uncertainty in estimating the insolation threshold of the inner edge (the runaway greenhouse limit) due only to clear-sky radiative transfer is ≈10% of modern Earth’s solar constant (i.e., ≈34 W m{sup 2} in global mean) among band models and ≈3% between the two line-by-line models. These comparisons show that future work is needed that focuses on improving water vapor absorption coefficients in both shortwave and longwave, as well as on increasing the resolution of stellar spectra in broadband models.

  18. DIFFERENCES IN WATER VAPOR RADIATIVE TRANSFER AMONG 1D MODELS CAN SIGNIFICANTLY AFFECT THE INNER EDGE OF THE HABITABLE ZONE

    International Nuclear Information System (INIS)

    Yang, Jun; Wang, Yuwei; Leconte, Jérémy; Forget, François; Wolf, Eric T.; Goldblatt, Colin; Feldl, Nicole; Merlis, Timothy; Koll, Daniel D. B.; Ding, Feng; Abbot, Dorian S.

    2016-01-01

    An accurate estimate of the inner edge of the habitable zone is critical for determining which exoplanets are potentially habitable and for designing future telescopes to observe them. Here, we explore differences in estimating the inner edge among seven one-dimensional radiative transfer models: two line-by-line codes (SMART and LBLRTM) as well as five band codes (CAM3, CAM4-Wolf, LMDG, SBDART, and AM2) that are currently being used in global climate models. We compare radiative fluxes and spectra in clear-sky conditions around G and M stars, with fixed moist adiabatic profiles for surface temperatures from 250 to 360 K. We find that divergences among the models arise mainly from large uncertainties in water vapor absorption in the window region (10 μ m) and in the region between 0.2 and 1.5 μ m. Differences in outgoing longwave radiation increase with surface temperature and reach 10–20 W m 2 ; differences in shortwave reach up to 60 W m 2 , especially at the surface and in the troposphere, and are larger for an M-dwarf spectrum than a solar spectrum. Differences between the two line-by-line models are significant, although smaller than among the band models. Our results imply that the uncertainty in estimating the insolation threshold of the inner edge (the runaway greenhouse limit) due only to clear-sky radiative transfer is ≈10% of modern Earth’s solar constant (i.e., ≈34 W m 2 in global mean) among band models and ≈3% between the two line-by-line models. These comparisons show that future work is needed that focuses on improving water vapor absorption coefficients in both shortwave and longwave, as well as on increasing the resolution of stellar spectra in broadband models.

  19. Different Techniques of Respiratory Support Do Not Significantly Affect Gas Exchange during Cardiopulmonary Resuscitation in a Newborn Piglet Model.

    Science.gov (United States)

    Mendler, Marc R; Maurer, Miriam; Hassan, Mohammad A; Huang, Li; Waitz, Markus; Mayer, Benjamin; Hummler, Helmut D

    2015-01-01

    There are no evidence-based recommendations on the use of different techniques of respiratory support and chest compressions (CC) during neonatal cardiopulmonary resuscitation (CPR). We studied the short-term effects of different ventilatory support strategies along with CC representing clinical practice on gas exchange [arterial oxygen saturation (SaO2), arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2)], hemodynamics and cerebral oxygenation. We hypothesized that in newborn piglets with cardiac arrest, use of a T-piece resuscitator (TPR) providing positive end-expiratory pressure (PEEP) improves gas exchange as measured by SaO2 during CPR as compared to using a self-inflating bag (SIB) without PEEP. Furthermore, we explored the effects of a mechanical ventilator without synchrony to CC. Thirty newborn piglets with asystole were randomized into three groups and resuscitated for 20 min [fraction of inspired oxygen (FiO2) = 0.21 for 10 min and 1.0 thereafter]. Group 1 received ventilation using a TPR [peak inspiratory pressure (PIP)/PEEP of 20/5 cm H2O, rate 30/min] with inflations interposed between CC (3:1 ratio). Group 2 received ventilation using a SIB (PIP of 20 cm H2O without PEEP, rate 30/min) with inflations interposed between CC (3:1 ratio). Group 3 received ventilation using a mechanical ventilator (PIP/PEEP of 20/5 cm H2O, rate 30/min). CC were applied with a rate of 120/min without synchrony to inflations. We found no significant differences in SaO2 between the three groups. However, there was a trend toward a higher SaO2 [TPR: 28.0% (22.3-40.0); SIB: 23.7% (13.4-52.3); ventilator: 44.1% (39.2-54.3); median (interquartile range)] and a lower PaCO2 [TPR: 95.6 mm Hg (82.1-113.6); SIB: 100.8 mm Hg (83.0-108.0); ventilator: 74.1 mm Hg (68.5-83.1); median (interquartile range)] in the mechanical ventilator group. We found no significant effect on gas exchange using different respiratory support strategies

  20. Do the levels of selected metals differ significantly between the roots of carious and non-carious teeth?

    International Nuclear Information System (INIS)

    Malara, Piotr; Kwapulinski, Jerzy; Malara, Beata

    2006-01-01

    Since the metals deposited in teeth during formation and mineralization processes are to a large extent retained, human teeth receive a considerable attention as the indicators of the heavy metal exposure. The use of permanent teeth is limited because the extraction of healthy permanent teeth just for this purpose is hardly acceptable. As the issue of the loss of elements from a carious lesion in the coronal part of a tooth remains controversial, the valuable material could only be the root of carious and fractured permanent teeth. However, to ensure the validity of the results, it should be ascertained that the levels of certain toxic and essential elements do not differ significantly between the roots of non-carious and carious teeth, and therefore this is the aim of this project. The levels of cadmium, chromium, copper, iron, manganese, lead, zinc, potassium, sodium, calcium and magnesium were determined in the roots of 344 permanent teeth (189 carious and 155 caries-free teeth) from the residents of Ruda Slaska, Poland, aged 18 to 34. No statistically significant difference between the concentration of these metals in the roots of non-carious and carious teeth was found. This finding applies to both the general population and after the grouping by donor's gender and tooth type. The concentration of lead, iron, calcium and manganese in the roots of non-carious and carious teeth exhibited dependence upon tooth type, as well as the concentration of potassium in the roots of carious teeth. Since the mineral composition of the roots of permanent teeth is similar for the non-carious, as well as the carious teeth, they can be indiscriminately selected for the tests required by a research project, as they will produce the comparable results. However, in the case of lead, iron, calcium, potassium and manganese, the comparison should be made after grouping by tooth type

  1. Quantifying Forest Spatial Pattern Trends at Multiple Extents: An Approach to Detect Significant Changes at Different Scales

    Directory of Open Access Journals (Sweden)

    Ludovico Frate

    2014-09-01

    Full Text Available We propose a procedure to detect significant changes in forest spatial patterns and relevant scales. Our approach consists of four sequential steps. First, based on a series of multi-temporal forest maps, a set of geographic windows of increasing extents are extracted. Second, for each extent and date, specific stochastic simulations that replicate real-world spatial pattern characteristics are run. Third, by computing pattern metrics on both simulated and real maps, their empirical distributions and confidence intervals are derived. Finally, multi-temporal scalograms are built for each metric. Based on cover maps (1954, 2011 with a resolution of 10 m we analyze forest pattern changes in a central Apennines (Italy reserve at multiple spatial extents (128, 256 and 512 pixels. We identify three types of multi-temporal scalograms, depending on pattern metric behaviors, describing different dynamics of natural reforestation process. The statistical distribution and variability of pattern metrics at multiple extents offers a new and powerful tool to detect forest variations over time. Similar procedures can (i help to identify significant changes in spatial patterns and provide the bases to relate them to landscape processes; (ii minimize the bias when comparing pattern metrics at a single extent and (iii be extended to other landscapes and scales.

  2. The clinical significance of axillary sentinel lymph node biopsy in different clinical stages breast cancer patients after neoadjuvant chemotherapy

    Institute of Scientific and Technical Information of China (English)

    Juan Xu; Xinhong Wu; Yaojun Feng; Feng Yuan; Wei Fan

    2013-01-01

    Objective:We aimed to study the success and false negative rate of sentinel lymph node biopsy (SLNB) in dif-ferent clinical stages breast cancer patients being carried out with neoadjuvant chemotherapy (NAC), and the clinical signifi-cance of SLNB, we conducting this trial. Methods:One hunderd and thirty-seven cases were enrol ed in this clinical research from March 2003 to March 2007. Al of the patients’ sentinel lymph nodes were detected with 99mTc-Dx and methylene blue. There were 61 patients with stage T1-2N0M0 carried SLNB without NAC (group A), 76 cases were carried out NAC 3-4 cycles before SLNB, including 39 T2-4N0-1M0 cases (group B) and 27 T2-4N2-3M0 cases (group C). The success and false negative rate of SLNB were analysed with chi-square test. Results:In group A, the successful and false negative rate of SLNB were 92.31%(36/39), 8.57%(3/35), and in group B and C were 92.31%(36/39), 8.57%(3/35) and 74.07%(20/27), 18.52%(5/27), respectively. The successful rate of group C decreased and false negative rate increased significantly compared with group A and B (P0.05). Conclusion:The SLNB can accurately predict lymph node status of axil ary lymph node in N0-1 stage patients with NAC, but in N2-3 stage patients the success rate decreased and false rate increased negative significantly.

  3. Difference of ore-bearing and non-ore-bearing pegmatite in the Guangshigou area and its research significance

    International Nuclear Information System (INIS)

    Zuo Wenqian; Zhang Zhanshi; Sha Yazhou; Rao Chaojun

    2011-01-01

    Guangshigou uranium deposit is one of the typical granite-pegmatite uranium deposits in China, the ore-body are located in the density zone of the outside contact zone of granite pluton. To distinguish the ore-bearing and Non-ore-bearing pegmatite is one of the most practices and have great significance for the effect of mineral exploration. Based on the field investigation and former research results, contrast research on the characteristics of the pegmatite on petrology, geophysical, geochemistry and stable isotopes have been carried out. It is pointed out that the ore-bearing pegmatite differ from the non-ore-bearing one from macro-and-micro-view in Guangshigou Uranium deposits, the main characteristics are summarized; the macro-and-micro signs are established, the genetic difference between the ore-bearing and non-ore-bearing pegmatite are discussed primarily. The achievements would be helpful for prospecting and researching of this type uranium deposits in China. (authors)

  4. The Urinary Microbiome Differs Significantly Between Patients With Chronic Prostatitis/Chronic Pelvic Pain Syndrome and Controls as Well as Between Patients With Different Clinical Phenotypes.

    Science.gov (United States)

    Shoskes, Daniel A; Altemus, Jessica; Polackwich, Alan S; Tucky, Barbara; Wang, Hannah; Eng, Charis

    2016-06-01

    To study the urinary microbiome of patients with Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) compared with controls. We identified 25 patients with CP/CPPS and 25 men who were either asymptomatic or only had urinary symptoms. Midstream urine was collected. Symptom severity was measured with the National Institutes of Health Chronic Prostatitis Symptom Index and clinical phenotype with UPOINT. Total DNA was extracted from the urine pellet and bacterial-specific 16Sr-DNA-capture identified by MiSeq sequencing. Taxonomic and functional bioinformatic analyses used principal coordinate analysis (PCoA)/MacQIIME, LEfSe, and PiCRUSt algorithms. Patients and controls were similar ages (52.3 vs 57.0 years, P = .27). For patients, median duration was 48 months, mean Chronic Prostatitis Symptom Index was 26.0, and mean UPOINT domains was 3.6. Weighted 3D UniFrac PCoA revealed tighter clustering of controls distinct from the wider clustering of cases (P = .001; α-diversity P = .005). Seventeen clades were overrepresented in patients, for example, Clostridia, and 5 were underrepresented, eg, Bacilli, resulting in predicted perturbations in functional pathways. PiCRUSt inferred differentially regulated pathways between cases and controls that may be of relevance including sporulation, chemotaxis, and pyruvate metabolism. PCoA-derived microbiomic differences were noted for neurologic/systemic domains (P = .06), whereas LEfSe identified differences associated with each of the 6 clinical features. Urinary microbiomes from patients with CP/CPPS have significantly higher alpha(phylogenetic) diversity which cluster differently from controls, and higher counts of Clostridia compared with controls, resulting in predicted perturbations of functional pathways which could suggest metabolite-specific targeted treatment. Several measures of severity and clinical phenotype have significant microbiome differences. Copyright © 2016 Elsevier Inc. All rights

  5. Correlation of the microstructure with viscosity and textural properties during milk fermentation by kombucha inoculum

    Directory of Open Access Journals (Sweden)

    Vukić Vladimir R.

    2014-01-01

    Full Text Available The aim of this study was to examine the changes in the microstructure, textural properties and viscosity of the gel formed during milk fermentation with kombucha inoculum and to establish a relationship between the microstructure and these properties. The values of the analyzed characteristics were measured during the gelation at 42°C at the following pHs: 5.4, 5.1, 4.8 and 4.6. The microstructure analysis revealed disappearance of coarse cluster structure and appearance of finer casein micelles network during fermentation. The obtained results showed significant differences in them viscosity and textural properties during fermentation, which is in accordance with their microstructure. The correlation of the examined properties and microstructure of the gel was established. [Projekat Ministarstva nauke Republike Srbije, br. 46009

  6. Investigation of the microstructures of ion beams emitted from PF-1000 at different angles to the Z-axis

    Energy Technology Data Exchange (ETDEWEB)

    Skladnik-Sadowska, E.; Czaus, K.; Malinowski, K.; Kwiatkowski, R.; Zebrowski, J. [The Andrzej Soltan Institute for Nuclear Studies, IPJ, 05-400 Otwock-Swierk (Poland); Sadowski, M.J. [The Andrzej Soltan Institute for Nuclear Studies, IPJ, 0R-400 Otwock-Swierk (Poland)] [Institute of Plasma Physics and Laser Microfusion, IPPLM, 01-497 Warsaw (Poland); Paduch, M.; Scholz, M. [Institute of Plasma Physics and Laser Microfusion, IPPLM, 01-497 Warsaw (Poland); Kubes, P. [Czech Technical University, CVUT, 166-27 Prague (Czech Republic); Garkusha, I.E. [Institute of Plasma Physics, NSC KIPT, 61-108 Kharkov (Ukraine); Talebitaher, A. [Plasma Radiation Sources Laboratory, NIE NTU, 637616 Singapore (Singapore)

    2011-07-01

    The paper describes diagnostics of fast ion beams emitted from the large PF-1000 facility operated at 21-27 kV, 290-480 kJ. The use was made of pinhole cameras equipped with PM-355 nuclear track detectors and placed at different angles to the discharge axis. The ion measurements performed at 0 degree angle, as well as those at 60 degrees angle showed a complex spatial structure of the fast ion beams. The ion measurements, which were for the first time performed in the upstream direction (at 180 degrees angle), have proved that some fast deuteron beams are emitted also in the upstream direction. This document is composed of a paper and a poster. (authors)

  7. Microstructures and mechanical properties of squeeze cast Al–5.0Cu–0.6Mn alloys with different Fe content

    International Nuclear Information System (INIS)

    Zhang, WeiWen; Lin, Bo; Zhang, DaTong; Li, YuanYuan

    2013-01-01

    Highlights: • The effect of Fe-rich phases on squeeze cast Al–Cu alloys with high Fe content. • Four kinds of Fe-rich phases may present in Al–Cu alloys. • There is great tolerance to Fe impurities in squeeze cast Al–Cu alloys. - Abstract: The microstructures and mechanical properties of gravity die cast and squeeze cast Al–5.0 wt% Cu–0.6 wt% Mn alloys with different Fe content have been studied using tensile test, optical microscope, scanning electron microscope, electron probe micro-analyzer and image analysis. The results show that four kinds of Fe-rich intermetallics may present in the final microstructures of the alloys: Chinese script α-Fe (Al 15 (FeMn) 3 (CuSi) 2 ) and Al 6 (FeMn), needle-like β-Fe(Al 7 Cu 2 Fe) and Al 3 (FeMn) when the Fe content increases from 0.1 wt% to 1.5 wt%. In the gravity die cast alloy with 0.5 wt% Fe, the Chinese script α-Fe presents as the main Fe-rich intermetallics, and a few needle-like β-Fe also exist. When the Fe content increases to 1.0 wt%, the main Fe-rich intermetallics change to needle-like Al 3 (FeMn) and Chinese-script Al 6 (FeMn). The needle-like β-Fe disappears when the Fe content is 0.5 wt% in the squeeze cast alloy with an applied pressure of 75 MPa. Furthermore, the secondary dendritic arm spacing of α(Al), the percentage of porosity and the volume fraction of the second intermetallics decrease distinctly in the squeeze cast alloy compared to the gravity die cast alloy. There is a peak value of ultimate strength and yield strength for the alloy with 0.5 wt% Fe. The elongations of the alloys decrease gradually with increasing Fe content and the elongation of the squeeze cast alloys is two times more than that of the gravity die cast alloys

  8. Microstructure and properties of the low-power-laser clad coatings on magnesium alloy with different amount of rare earth addition

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Rundong; Li, Zhiyong, E-mail: lizhiyong@nuc.edu.cn; Li, Xiaoxi; Sun, Qi

    2015-10-30

    Highlights: • The low-power-laser was used to obtain the excellent coatings with different amount of Y{sub 2}O{sub 3} addition. • The addition of rare earth oxide Y{sub 2}O{sub 3} refined and purified the microstructure of the coatings, meanwhile, increased the thickness of the coatings and reduced the dilution of cladding materials from based alloy. • The primary phases in the coatings are Mg{sub 32}Al{sub 47}Cu{sub 7}, MgCu{sub 6}Al{sub 5}, Al{sub 2}CuMg and Al{sub 12}Mg{sub 17}. The A{sub l4}MgY and MgAl{sub 2}O{sub 4} phase can be found in Y{sub 2}O{sub 3}-modified coatings. • The micro-hardness and the abrasion resistance of the coatings with Y{sub 2}O{sub 3} had been improved obviously compared with the coatings without Y{sub 2}O{sub 3}. • The corrosion resistance of the AZ91D magnesium alloy had been improved by laser cladding. And the effect of Y{sub 2}O{sub 3} on the corrosion potential of the coatings was less than the effect of Y{sub 2}O{sub 3} on corrosion current density of the coatings. - Abstract: Due to the low-melting-point and high evaporation rate of magnesium at elevated temperature, high power laser clad coating on magnesium always causes subsidence and deterioration in the surface. Low power laser can reduce the evaporation effect while brings problems such as decreased thickness, incomplete fusion and unsatisfied performance. Therefore, low power laser with selected parameters was used in our research work to obtain Al–Cu coatings with Y{sub 2}O{sub 3} addition on AZ91D magnesium alloy. The addition of Y{sub 2}O{sub 3} obviously increases thickness of the coating and improves the melting efficiency. Furthermore, the effect of Y{sub 2}O{sub 3} addition on the microstructure of laser clad Al–Cu coatings was investigated by scanning electron microscopy. The energy-dispersive spectrometer (EDS) and X-ray diffractometer (XRD) were used to examine the elemental and phase compositions of the coatings. The properties were investigated

  9. Religious Freedom and Equality as Celebration of Difference: A Significant Development in Recent South African Constitutional Case-Law

    Directory of Open Access Journals (Sweden)

    L du Plessis

    2009-12-01

    Full Text Available This contribution focuses on the way in which the South African Constitutional Court has, since 1997, been dealing with the (seemingly eccentric claims of (assumedly idiosyncratic 'religious Others'. Developments in this regard have, for the time being at least, culminated in the Constitutional Court's landmark judgment in MEC for Education: KwaZulu Natal v Pillay 2008 (2 BCLR 99 (CC, 2008 (1 SA 474 (CC (hereafter Pillay. Constitutional Court judgments since 1997 manifesting the adjudication of such unconventional claims are assessed, eventually getting to Pillay as benchmark. This remarkable judgment, dealing with a deceptively mundane issue, has played a considerable role in fleshing out a jurisprudence of difference, putting an adherent of a vulnerable, minority religion in the right. This is not just a high point in the adjudication of constitutional entitlements of the religious (and cultural Other in South Africa, but also a significant contribution to the growth of a jurisprudence sensitive to the predicaments and constitutional entitlements of unconventional, 'non-mainstream' claimants of religious (and cultural rights. Finally Pillay illustrates that the constitutional guarantee of the right to freedom of religion, conscience, belief and opinion (entrenched in section 15(1 of the Constitution of Republic of South Africa 1996 can be crucially dependent upon due effect being given to the proscription of unfair discrimination on the grounds of religion, conscience, belief and opinion elsewhere (namely in section 9(3 of the Constitution.

  10. Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zhanyun; Chen Min; Chen Dihu [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275 (China); Pan Shirong, E-mail: stscdh@mail.sysu.edu.c [Artificial Heart Lab, the 1st Affiliate Hospital of Sun Yat-Sen University, Guangzhou 510080 (China)

    2010-10-01

    In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.

  11. Microstructure and High-temperature Wear Behavior of Hot-dipped Aluminized Coating on Different Substrate Materials

    Directory of Open Access Journals (Sweden)

    ZHOU De-qin

    2018-02-01

    Full Text Available The aluminized 45 and H13 steel were prepared via hot-dipped aluminizing and subsequently high-temperature diffusion treatment. The phase, morphology and composition of aluminized coating were characterized by XRD,SEM and EDS methods. Comparative study was performed on unlubricated sliding wear behavior of plating under different substrates on a pin-on-disc wear tester, and the wear mechanism was explored. The results show that the coating is composed of ductile phases FeAl and Fe3Al. Kikendall porosity parallel to the surface exists around the interface of the two phases; because of the carbide particles agglomeration, the bond between the coating and H13 steel is apparently inferior to that in the case of 45 steel; the aluminized 45 steel possesses an excellent wear resistance under 50-200N at 400℃, whereas mild-to-severe wear transition occurs when the temperature increases to 600℃. The wear rate of the aluminized H13 steel reaches the lowest at 400℃, then slightly increases at 600℃. The wear mechanisms of Fe-Al coating are mainly predominated by oxidative mild wear, whereas the extrusion wear prevails in the process for aluminized 45 steel at 600℃.

  12. Normal white matter microstructure in women long-term recovered from anorexia nervosa: A diffusion tensor imaging study.

    Science.gov (United States)

    Bang, Lasse; Rø, Øyvind; Endestad, Tor

    2018-01-01

    Studies point to white matter (WM) microstructure alterations in both adolescent and adult patients with anorexia nervosa (AN). These include reduced fractional anisotropy in several WM fiber tracts, suggesting reduced WM integrity. The extent to which these alterations are reversible with recovery from AN is unclear. There is a paucity of research investigating the presence of WM microstructure alterations in recovered AN patients, and results are inconsistent. This study aimed to investigate the presence of WM microstructure alterations in women long-term recovered from AN. Twenty-one adult women who were recovered from AN for at least 1 year were compared to 21 adult comparison women. Participants were recruited via user-organizations for eating disorders, local advertisements, and online forums. Diffusion tensor imaging was used to compare WM microstructure between groups. Correlations between WM microstructure and clinical characteristics were also explored. There were no statistically significant between-group differences in WM microstructure. These null findings remained when employing liberal alpha level thresholds. Furthermore, there were no statistically significant correlations between WM microstructure and clinical characteristics. Our findings showed normal WM microstructure in long-term recovered patients, indicating the alterations observed during the acute phase are reversible. Given the paucity of research and inconsistent findings, future studies are warranted to determine the presence of WM microstructure alterations following recovery from AN. © 2017 Wiley Periodicals, Inc.

  13. Age-related changes of vertical and horizontal lumbar vertebral trabecular 3D bone microstructure is different in women and men.

    Science.gov (United States)

    Thomsen, Jesper Skovhus; Niklassen, Andreas Steenholt; Ebbesen, Ebbe Nils; Brüel, Annemarie

    2013-11-01

    The study presents a 3D method for subdividing a trabecular network into horizontal and vertical oriented bone. This method was used to investigate the age related changes of the bone volume fraction and thickness of horizontal and vertical trabeculae in human lumbar vertebral bone estimated with unbiased 3D methods in women and men over a large age-range. The study comprised second lumbar vertebral body bone samples from 40 women (aged 21.7-96.4years, median 56.6years) and 39 men (aged 22.6-94.6years, median 55.6years). The bone samples were μCT scanned and the 3D microstructure was quantified. A voxel based algorithm inspecting the local neighborhood is presented and used to segment the trabecular network into horizontal and vertical oriented bone. For both women and men BV/TV decreased significantly with age, Tb.Th* was independent of age, while SMI increased significantly with age. Vertical (BV.vert/TV) and horizontal (BV.horz/TV) bone volume fraction decreased significantly with age for both sexes. BV.vert/TV decreased significantly faster with age for women than for men. Vertical (Tb.Th*.vert) and horizontal (Tb.Th*.horz) trabecular thickness were independent of age, while Tb.Th*.horz/Tb.Th*.vert decreased significantly with age for both sexes. Additionally, the 95th percentile of the trabecular thickness distribution increased significantly with age for vertical trabeculae in women, whereas it was independent of age in men. In conclusion, we have shown that vertical and horizontal oriented bone density decreases with age in both women and men, and that vertical oriented bone is lost more quickly in women than in men. Furthermore, vertical and horizontal trabecular thickness were independent of age, whereas the horizontal to vertical trabecular thickness ratio decreased significantly with age indicating a relatively more pronounced thinning of horizontal trabeculae. Finally, the age-related loss of trabecular elements appeared to result in a compensatory

  14. Evidence for the different physiological significance of the 6- and 2-minute walk tests in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Motl Robert W

    2012-03-01

    Full Text Available Abstract Background Researchers have recently advocated for the 2-minute walk (2MW as an alternative for the 6-minute walk (6MW to assess long distance ambulation in persons with multiple sclerosis (MS. This recommendation has not been based on physiological considerations such as the rate of oxygen consumption (V·O2 over the 6MW range. Objective This study examined the pattern of change in V·O2 over the range of the 6MW in a large sample of persons with MS who varied as a function of disability status. Method Ninety-five persons with clinically-definite MS underwent a neurological examination for generating an Expanded Disability Status Scale (EDSS score, and then completion of the 6MW protocol while wearing a portable metabolic unit and an accelerometer. Results There was a time main effect on V·O2 during the 6MW (p = .0001 such that V·O2 increased significantly every 30 seconds over the first 3 minutes of the 6MW, and then remained stable over the second 3 minutes of the 6MW. This occurred despite no change in cadence across the 6MW (p = .84. Conclusions The pattern of change in V·O2 indicates that there are different metabolic systems providing energy for ambulation during the 6MW in MS subjects and steady state aerobic metabolism is reached during the last 3 minutes of the 6MW. By extension, the first 3 minutes would represent a test of mixed aerobic and anaerobic work, whereas the second 3 minutes would represent a test of aerobic work during walking.

  15. Microstructural development in physical vapour-deposited partially stabilized zirconia thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Y. H. (Center for Intelligent Processing of Materials, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609-2280 (United States)); Biederman, R.R. (Center for Intelligent Processing of Materials, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609-2280 (United States)); Sisson, R.D. Jr. (Center for Intelligent Processing of Materials, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609-2280 (United States))

    1994-10-01

    The effects of processing parameters of physical vapour deposition on the microstructure of partially stabilized zirconia (PSZ) thermal barrier coatings have been experimentally investigated. Emphasis has been placed on the crystallographic texture of the PSZ coatings and the microstructure of the top surface of the PSZ coatings as well as the metal-ceramic interface. The variations in the deposition chamber temperature, substrate thickness, substrate rotation and vapour incidence angle resulted in the observation of significant differences in the crystallographic texture and microstructure of the PSZ coatings. ((orig.))

  16. Estimating integrated variance in the presence of microstructure noise using linear regression

    Science.gov (United States)

    Holý, Vladimír

    2017-07-01

    Using financial high-frequency data for estimation of integrated variance of asset prices is beneficial but with increasing number of observations so-called microstructure noise occurs. This noise can significantly bias the realized variance estimator. We propose a method for estimation of the integrated variance robust to microstructure noise as well as for testing the presence of the noise. Our method utilizes linear regression in which realized variances estimated from different data subsamples act as dependent variable while the number of observations act as explanatory variable. We compare proposed estimator with other methods on simulated data for several microstructure noise structures.

  17. Physical activity is associated with changes in knee cartilage microstructure.

    Science.gov (United States)

    Halilaj, E; Hastie, T J; Gold, G E; Delp, S L

    2018-06-01

    The purpose of this study was to determine if there is an association between objectively measured physical activity and longitudinal changes in knee cartilage microstructure. We used accelerometry and T 2 -weighted magnetic resonance imaging (MRI) data from the Osteoarthritis Initiative, restricting the analysis to men aged 45-60 years, with a body mass index (BMI) of 25-27 kg/m 2 and no radiographic evidence of knee osteoarthritis. After computing 4-year changes in mean T 2 relaxation time for six femoral cartilage regions and mean daily times spent in the sedentary, light, moderate, and vigorous activity ranges, we performed canonical correlation analysis (CCA) to find a linear combination of times spent in different activity intensity ranges (Activity Index) that was maximally correlated with a linear combination of regional changes in cartilage microstructure (Cartilage Microstructure Index). We used leave-one-out pre-validation to test the robustness of the model on new data. Nineteen subjects satisfied the inclusion criteria. CCA identified an Activity Index and a Cartilage Microstructure Index that were significantly correlated (r = .82, P microstructural changes in different cartilage regions than it is with univariate or cumulative changes, likely because this index separates the effect of activity, which is greater in the medial loadbearing region, from that of patient-specific natural aging. Copyright © 2018 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  18. Effect of malva nut gum (purified and crude), sodium chloride and phosphate on cooking, texture, colour, rheology and microstructure of different chicken meat batters.

    Science.gov (United States)

    Barbut, S; Somboonpanyakul, P; Quinton, M; Smith, A

    2009-01-01

    1. In the first experiment, the effect of adding purified malva nut gum (PMG) to comminuted poultry breast meat batters formulated with different contents of sodium chloride (NaCl; 10 to 30 g/kg) and tripolyphosphate (TPP; 0 and 5 g/kg) was studied. 2. Increasing salt (sodium chloride) content, along with the addition of 1 g/kg PMG, was beneficial in reducing cooking loss. At all salt contents, batters with PMG showed lower springiness than batters without PMG. Adding PMG to the batter with 20 g/kg salt and TPP decreased fracture force, springiness and chewiness. 3. In a second experiment, the effects of PMG (0.0, 3.0 and 6.0 g/kg), crude malva nut gum (CMG; 3.0 g/kg) and TPP (0.0 and 4.0 g/kg) on cooking loss, fat loss, colour, texture, rheology and microstructure of emulsified chicken meat batters were studied. 4. Increasing PMG reduced cooking and fat losses. Adding TPP increased hardness, springiness, cohesiveness and chewiness. The 1.0 g/kg PMG and TPP provided the greatest hardness. The batter with 3.0 g/kg PMG resulted in the lowest lightness (L*) and highest redness (a*). Adding PMG and TPP resulted in stable batters, as was evident by light microscopy results. The rheological evaluation showed the highest G' in the batter with 4.0 g/kg TPP followed in decreasing order by the batters containing TPP plus 3.0 g/kg PMG, TPP plus 1.0 g/kg PMG, 3.0 g/kg PMG, 1.0 g/kg PMG, 3.0 g/kg CMG and the control. 5. Overall, the results are important for developing new applications where malva nut gum can be used to improve yield and stability of meat products.

  19. Microstructures and mechanical properties of heat-treated Al–5.0Cu–0.5Fe squeeze cast alloys with different Mn/Fe ratio

    International Nuclear Information System (INIS)

    Zhang, Weiwen; Lin, Bo; Fan, Jianlei; Zhang, Datong; Li, Yuanyuan

    2013-01-01

    The Al–5.0 wt% Cu–0.5 wt% Fe alloys with different Mn/Fe ratio were prepared by squeeze casting. Various test techniques, including tensile test, image analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), electron probe micro-analyzer (EPMA) and transmission electron microscopy (TEM) were used to examine the microstructures and mechanical properties of the alloys in T5 heat-treated condition. The results show that the β-Fe (Al 7 Cu 2 Fe) is stable and its needle-like morphology is maintained after T5 heat treatment. However, the Chinese script Al m Fe, α-Fe or Al 6 (FeMn) partially transform to a new Chinese script Cu-rich α(CuFe) (Al 7 Cu 2 Fe or Al 7 Cu 2 (FeMn)), which is harmful to the mechanical properties of the alloys due to the decrease of the Cu content in α(Al) matrix. The optimal Mn/Fe ratio is determined by the morphology of Fe-rich intermetallics, volume fraction of θ′ and T (Al 20 Cu 2 Mn 3 ), size of α(Al) dendrite and porosity. Excessive Mn/Fe ratio will deteriorate the mechanical properties of the alloys due to the increase of the total amount of porosity and the Fe-rich intermetallics. When the Mn/Fe ratio is 1.6 and 1.2 for the applied pressure of 0 MPa and 75 MPa, respectively, the needle-like β-Fe phase is completely converted to the Chinese script Fe-rich intermetallics. The ultimate tensile strength, yield strength and elongation of the T5 heat-treated alloy with the Mn/Fe ratio of 1.2 and applied pressure of 75 MPa reach 395 MPa, 335 MPa and 14%, respectively

  20. Cytogenetical and morphological features reveal significant differences among Venezuelan and Brazilian samples of Mugil curema (Teleostei: Mugilidae

    Directory of Open Access Journals (Sweden)

    Mauro Nirchio

    Full Text Available Karyotype of M. curema from the Gulf of Mexico and Brazil have been reported as possessing chromosome complement with 2n=28 and FN=48, whereas specimens from Venezuela has been reported as possessing a diploid number 2n=24 and a conserved FN (48. Although at first sight this variation suggests the presence of a chromosomal intraspecific (interpopulational variability, the possibility that we are dealing with two different species was examined. This work revisit the karyotypes of M. curema from Venezuela and Brazil, including new data on C-banding, and NOR localization, and compares morphologic characteristics of samples from both localities. Thus, besides diploid number, the constitutive heterochromatin distribution and NORs location, mark other differences between M. curema Cytotype 1 (2n=28; FN=48 and Cytotype 2 (2n=24; NF=48. Moreover, morphologic comparison revealed differences in the scale counts and pectoral fin rays: 35 scales in the middle body line and 15 pectoral fin rays in specimens possessing the karyotype 2n=28, compared with 37-39 scales in the middle body line and 17 pectoral fin rays in specimens with the karyotype 2n=24. These differences lead us to suggest that both cytotypes are not related merely to geographic polytipic variations but could correspond to different species.

  1. Effect of Low-Dose MDCT and Iterative Reconstruction on Trabecular Bone Microstructure Assessment.

    Science.gov (United States)

    Kopp, Felix K; Holzapfel, Konstantin; Baum, Thomas; Nasirudin, Radin A; Mei, Kai; Garcia, Eduardo G; Burgkart, Rainer; Rummeny, Ernst J; Kirschke, Jan S; Noël, Peter B

    2016-01-01

    We investigated the effects of low-dose multi detector computed tomography (MDCT) in combination with statistical iterative reconstruction algorithms on trabecular bone microstructure parameters. Twelve donated vertebrae were scanned with the routine radiation exposure used in our department (standard-dose) and a low-dose protocol. Reconstructions were performed with filtered backprojection (FBP) and maximum-likelihood based statistical iterative reconstruction (SIR). Trabecular bone microstructure parameters were assessed and statistically compared for each reconstruction. Moreover, fracture loads of the vertebrae were biomechanically determined and correlated to the assessed microstructure parameters. Trabecular bone microstructure parameters based on low-dose MDCT and SIR significantly correlated with vertebral bone strength. There was no significant difference between microstructure parameters calculated on low-dose SIR and standard-dose FBP images. However, the results revealed a strong dependency on the regularization strength applied during SIR. It was observed that stronger regularization might corrupt the microstructure analysis, because the trabecular structure is a very small detail that might get lost during the regularization process. As a consequence, the introduction of SIR for trabecular bone microstructure analysis requires a specific optimization of the regularization parameters. Moreover, in comparison to other approaches, superior noise-resolution trade-offs can be found with the proposed methods.

  2. [Different explanatory models for addictive behavior in Turkish and German youths in Germany: significance for prevention and treatment].

    Science.gov (United States)

    Penka, S; Krieg, S; Hunner, Ch; Heinz, A

    2003-07-01

    Due to cultural and social barriers, immigrants seldom frequent centers for information, counseling, and treatment of addictive disorders. We examine cultural differences in the explanatory models of addictive behavior among Turkish and German youths in Germany with statistical devices that map the concepts associated with problems of addiction. Relevant differences were found between the disorder concepts of Turkish and German youth. German but not Turkish youths classified eating disorders among severe addictive disorders and associated them with embarrassment and shame. Concerning substance abuse, German but not Turkish youths clearly differentiated between illegal drug abuse and the abuse of alcohol and nicotine. Nearly half of all Turkish youths rejected central medical concepts such as "physical dependence" or "reduced control of substance intake" as completely inadequate to characterize problems of addictive behavior. Preventive information programs must consider these differences and use concepts that are accepted and clearly associated with addictive behavior by immigrant populations.

  3. Organizational Citizenship Behavior, Job Satisfaction and Commitment to School: Is There Any Significant Difference between Male and Female Teachers?

    Science.gov (United States)

    Jenaabadi, Hossein; Okati, Ehsan; Sarhadi, Aliyavar

    2013-01-01

    This research investigated the gender differences in job satisfaction, organizational commitment and organizational citizenship behavior in sample included 200 male and 200 female teachers and 80 male managers in boy elementary schools in Zahedan. Data was collected by means of questionnaires and was analyzed through Factorial Analysis of…

  4. Clinical significance of fibromyalgia syndrome in different rheumatic diseases: Relation to disease activity and quality of life.

    Science.gov (United States)

    El-Rabbat M, Sarah; Mahmoud, Nermeen K; Gheita, Tamer A

    2017-04-11

    To describe the frequencies of fibromyalgia syndrome (FMS) in various rheumatic diseases; rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and Behçets disease (BD) patients and to study the relation to clinical manifestations and quality of life (QoL). 160 patients (50 RA, 50 SLE, 30 SSc and 30 BD) and matched corresponding healthy controls were included. Disease activity was assessed using disease activity score in 28 joints (DAS28) for RA, SLE Disease Activity index (SLEDAI), modified Rodnan skin score for SSc and BD Current Activity Form (BDCAF). The QoL was also recorded. Severity in FMS cases was estimated using the revised Fibromyalgia Impact Questionnaire score. In the RA, SLE, SSc and BD patients, FMS was found in 14%, 18%, 6.67% and 3.33% respectively compared to 2.1%, 3%, 3.3% and 0% in their corresponding controls. In RA patients, DAS28 was significantly higher in those with FMS (p=0.009) and significantly correlated with both Widespread Pain Index (WPI) (p=0.011) and Symptom Severity (SS) scale (p=0.012). The QoL scale in those with FMS was significantly worse (62.3±7.9) compared to those without (71.7±14.4) (p=0.023). In SLE patients, The WPI and SS both significantly correlated with the presence of thrombosis (r=0.28, p=0.049 and r=0.43, p=0.002 respectively). The SS scale tended to correlate with the SLEDAI (r=0.28, p=0.05). In BD patients, BDCAF and WPI significantly correlated (p=0.03). Fibromyalgia syndrome is more frequent in rheumatic diseases, could be related to the disease activity in RA and BD patients and to thrombosis in SLE and affected the QoL in RA. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

  5. Diagnostic significance of measurements of specific IgG antibodies to Pseudomonas aeruginosa by three different serological methods

    DEFF Research Database (Denmark)

    Pressler, T.; Karpati, F.; Granstrom, M.

    2008-01-01

    to characterize patients with different infection status. Elevated levels of specific anti-Pseudomonas antibodies showed to be the risk factor for developing chronic Pa infection. Due to the specificity of the tests, antibiotic treatment based on serology might be considered in selected cases. There is a window...... of opportunity for suppression and eradication of initial P. aeruginosa infection making measurement of specific anti-Pseudomonas antibodies helpful Udgivelsesdato: 2009/1...

  6. Differences in radiosensitivity among cells in culture and in experimental tumours: Significance for the effectiveness of human cancer therapy

    International Nuclear Information System (INIS)

    Barendsen, G.W.; Amsterdam Univ.

    1987-01-01

    Problems in the application of radiobiological data on various types of models, cell in vitro, experimental tumours, and clinical models, to the prediction of tumour radiocurability are discussed. On the basis of observations on cells in culture and experimental tumours it is suggested that heterogeneity in responsiveness of tumours in patients is caused in a large part by differences in intrinsic cellular radiosensitivity. Methods and developments are reviewed, which may yield better assays for the prediction of tumour responsiveness to treatments. (Auth.)

  7. The Expression of miR-192 and Its Significance in Diabetic Nephropathy Patients with Different Urine Albumin Creatinine Ratio

    Directory of Open Access Journals (Sweden)

    Xiaoyu Ma

    2016-01-01

    Full Text Available Objective. To investigate the expression of miR-192 and its significance in diabetic nephropathy (DN patients. Methods. 464 patients with type 2 diabetes mellitus (T2DM were divided into normal albuminuria group (NA, n=157, microalbuminuria group (MA, n=159, and large amount of albuminuria group (LA, n=148. 127 healthy persons were selected as the control group (NC, n=127. The serum miR-192 levels were detected by Real-Time PCR and transforming growth factor-β1 (TGF-β1 and fibronectin (FN were detected by enzyme-linked immunosorbent assay. The relationships among these parameters were analyzed by Pearson correlation analysis and multiple linear regression analysis. Results. The miR-192 in the LA group was significantly lower than other groups, which was lower in the MA group than in the NA group (P<0.01. The TGF-β1 and FN in the LA group were significantly higher than other groups, which were higher in the MA group than in the NA group (P<0.01. The expression of miR-192 was negatively correlated with TGF-β1, FN, and Ln (UACR and miR-192, TGF-β1, and FN were independent relevant factors affecting Ln (UACR in T2DM (P<0.01. Conclusions. These findings indicate that the levels of miR-192 were lower accompanied by the decrease of urine albumin creatinine ratio (UACR and the association between miR-192 and nephritic fibrosis in DN.

  8. Significant contribution of stacking faults to the strain hardening behavior of Cu-15%Al alloy with different grain sizes.

    Science.gov (United States)

    Tian, Y Z; Zhao, L J; Chen, S; Shibata, A; Zhang, Z F; Tsuji, N

    2015-11-19

    It is commonly accepted that twinning can induce an increase of strain-hardening rate during the tensile process of face-centered cubic (FCC) metals and alloys with low stacking fault energy (SFE). In this study, we explored the grain size effect on the strain-hardening behavior of a Cu-15 at.%Al alloy with low SFE. Instead of twinning, we detected a significant contribution of stacking faults (SFs) irrespective of the grain size even in the initial stage of tensile process. In contrast, twinning was more sensitive to the grain size, and the onset of deformation twins might be postponed to a higher strain with increasing the grain size. In the Cu-15 at.%Al alloy with a mean grain size of 47 μm, there was a stage where the strain-hardening rate increases with strain, and this was mainly induced by the SFs instead of twinning. Thus in parallel with the TWIP effect, we proposed that SFs also contribute significantly to the plasticity of FCC alloys with low SFE.

  9. In Situ Study of Phase Transformations during Non-Isothermal Tempering of Bainitic and Martensitic Microstructures

    Directory of Open Access Journals (Sweden)

    S. Hesamodin Talebi

    2017-09-01

    Full Text Available Phase transformations during non-isothermal tempering of bainitic or martensitic microstructures obtained after quenching of a medium-carbon low-alloy steel was studied. The microstructures correspond to different locations of an as-quenched large-sized forged ingot used as a die material in the automotive industry. High-resolution dilatometry experiments were conducted to simulate the heat treatment process, as well as to investigate different phenomena occurring during non-isothermal tempering. The microstructures were characterized using optical and scanning electron microscopy. Dilatometry analyses demonstrated that tempering behavior varied significantly from bainitic to martensitic microstructures. Retained austenite, which exists between bainitic ferrite sheaves, decomposes to lower bainite causing a remarkable volume increase. It was found that this decomposition finishes below 386 °C. By contrast, martensite tempering was accompanied with a volume decrease due to the decomposition of medium-carbon martensite to low carbon martensite and carbides.

  10. The effect of substrate microstructure on high temperature oxidation of Zr alloy

    International Nuclear Information System (INIS)

    Li, H.; Lin, J.; Szpunar, J.

    2005-01-01

    'Full text:' Specimens with various substrate microstructures of Zr-2.5Nb, Zircaloy 4 and pure Zr have been oxidized at 500C in air. Oxidation kinetics is measured and the microstructures of both oxide and substrate are analyzed. The difference in oxidation kinetics among various specimens is significant. This difference is explained by the distribution of oxide grain size, grain shape and grain boundary, which are controlled by substrate grain size and β phase distribution. The previously proposed model of Zr oxidation is used to predict oxidation kinetics and oxide microstructure from substrate microstructure. Computer simulation based on the model is performed and simulation results are compared with the experimental results. (author)

  11. No significant difference in depression rate in employed and unemployed in a pair-matched study design.

    Science.gov (United States)

    Mihai, Adriana; Ricean, Alina; Voidazan, Septimiu

    2014-01-01

    The main objective of this study was to evaluate the differences of depression rate in employed and unemployed persons in the period of financial and economic crisis in Romania, in a pair-matched study design. The cross-sectional study uses a pair match design (395 pairs) of two groups of employed and unemployed persons. Other socio-demographic risk factors of depression (gender, age, marital status, residence, ethnicity, educational level, and profession) were controlled. The study was done in a historical period of economic crisis, 2009-2010. For the screening of depression we used the patient health questionnaire-9. There were no statistical differences (p = 0.054) between the depression rates in the employed (17.98%) and unemployed (23.80%) samples. The depression rate in both groups was higher in females, age (51-55), marital status (divorced), living in the rural area, with a low level of education and poverty. Suicidal ideas are more frequent in men, employed persons with low level of education and in unemployed persons with medium level of education. The exposure to short term unemployment status was not associated with change in depression rate in the period of financial and economic crisis in Romania, comparing with controls pair-matched. Unemployment status increases the depression rate only in vulnerable groups such as single or divorced women; and suicidal ideas were associated with the unemployment status (longer than 8 months) in men from rural area with medium level of education.

  12. No significant difference in depression rate in employed and unemployed in a pair-matched study design

    Directory of Open Access Journals (Sweden)

    Adriana eMihai

    2014-07-01

    Full Text Available The main objective of this study was to evaluate the differences of depression rate in employed and unemployed persons in the period of financial and economic crisis in Romania, in a pair-matched study design.Method: The cross sectional study uses a pair match design (395 pairs of two groups of employed and unemployed persons. Other socio-demographic risk factors of depression (gender, age, marital status, residence, ethnicity, educational level and profession were controlled. The study was done in a historical period of economic crisis, 2009-2010. For the screening of depression we used the Patient Health Questionnaire PHQ – 9.Results: There were no statistical differences (p=0.054 between the depression rates in the employed (17.98% and unemployed (23.80% samples. The depression rate in both groups was higher in females, age (51-55, marital status (divorced, living in the rural area, with a low level of education, poverty. Suicidal ideas are more frequent in men, employed persons with low level of education and in unemployed persons with medium level of education.Conclusion: The exposure to short term unemployment status was not associated with change in depression rate in the period of financial and economic crisis in Romania, comparing with controls pair-matched. Unemployment status increases the depression rate only in vulnerable groups such as single or divorced women; and suicidal ideas were associated with the unemployment status (longer than 8 months in men from rural area with medium level of education.

  13. Human microRNA oncogenes and tumor suppressors show significantly different biological patterns: from functions to targets.

    Directory of Open Access Journals (Sweden)

    Dong Wang

    Full Text Available MicroRNAs (miRNAs are small noncoding RNAs which play essential roles in many important biological processes. Therefore, their dysfunction is associated with a variety of human diseases, including cancer. Increasing evidence shows that miRNAs can act as oncogenes or tumor suppressors, and although there is great interest in research into these cancer-associated miRNAs, little is known about them. In this study, we performed a comprehensive analysis of putative human miRNA oncogenes and tumor suppressors. We found that miRNA oncogenes and tumor suppressors clearly show different patterns in function, evolutionary rate, expression, chromosome distribution, molecule size, free energy, transcription factors, and targets. For example, miRNA oncogenes are located mainly in the amplified regions in human cancers, whereas miRNA tumor suppressors are located mainly in the deleted regions. miRNA oncogenes tend to cleave target mRNAs more frequently than miRNA tumor suppressors. These results indicate that these two types of cancer-associated miRNAs play different roles in cancer formation and development. Moreover, the patterns identified here can discriminate novel miRNA oncogenes and tumor suppressors with a high degree of accuracy. This study represents the first large-scale bioinformatic analysis of human miRNA oncogenes and tumor suppressors. Our findings provide help for not only understanding of miRNAs in cancer but also for the specific identification of novel miRNAs as miRNA oncogenes and tumor suppressors. In addition, the data presented in this study will be valuable for the study of both miRNAs and cancer.

  14. Significant differences in the use of healthcare resources of native-born and foreign born in Spain

    Science.gov (United States)

    Carrasco-Garrido, Pilar; Jiménez-García, Rodrigo; Barrera, Valentin Hernández; de Andrés, Ana López; de Miguel, Ángel Gil

    2009-01-01

    Background In the last decade, the number of foreign residents in Spain has doubled and it has become one of the countries in the European Union with the highest number of immigrants There is no doubt that the health of the immigrant population has become a relevant subject from the point of view of public healthcare. Our study aimed at describing the potential inequalities in the use of healthcare resources and in the lifestyles of the resident immigrant population of Spain. Methods Cross-sectional, epidemiological study from the Spanish National Health Survey (NHS) in 2006, from the Ministry of Health and Consumer Affairs. We have worked with individualized secondary data, collected in the Spanish National Health Survey carried out in 2006 and 2007 (SNHS-06), from the Ministry of Health and Consumer Affairs. The format of the SNHS-06 has been adapted to the requirements of the European project for the carrying out of health surveys. Results The economic immigrant population resident in Spain, present diseases that are similar to those of the indigenous population. The immigrant population shows significantly lower values in the consumption of alcohol, tobacco and physical activity (OR = 0.76; CI 95%: 0.65–0.89, they nonetheless perceive their health condition as worse than that reported by the autochthonous population (OR = 1.63, CI 95%: 1.34–1.97). The probability of the immigrant population using emergency services in the last 12 months was significantly greater than that of the autochthonous population (OR = 1.31, CI 95%: 1.12–1.54). This situation repeats itself when analyzing hospitalization data, with values of probability of being hospitalized greater among immigrants (OR = 1.39, CI 95%: 1.07–1.81). Conclusion The economic immigrants have better parameters in relation to lifestyles, but they have a poor perception of their health. Despite the fact that immigrant population shows higher percentages of emergency attendance and hospitalization than

  15. Peripheral arterial volume distensibility: significant differences with age and blood pressure measured using an applied external pressure

    International Nuclear Information System (INIS)

    Zheng, Dingchang; Murray, Alan

    2011-01-01

    A new arterial distensibility measurement technique was assessed in 100 healthy normotensive subjects. Arterial transmural pressures on the whole right arm were reduced with a 50 cm long cuff inflated to 10, 20, 30 and 40 mmHg. The electrocardiogram, and finger and ear photoplethysmograms were recorded simultaneously. Arm pulse propagation time, pulse wave velocity (PWV) and arterial volume distensibility were determined. With a 40 mmHg reduction in transmural pressure, arm pulse propagation time increased from 61 to 83 ms, PWV decreased from 12 to 8 m s −1 and arterial distensibility increased from 0.102% to 0.232% per mmHg (all P < 0.0001). At all cuff pressures, arterial distensibility was significantly related to resting mean arterial pressure (MAP), diastolic blood pressure (DBP) and age, and for systolic blood pressure at 30 and 40 mmHg (all P < 0.05). At 40 mmHg cuff pressure, arterial distensibility fell by 54% for a MAP increase from 75 to 105 mmHg, 57% for a DBP increase from 60 to 90 mmHg and 47% for an age increase from 20 to 70 years. These changes were more than double than those without cuff pressure. Our technique showed that systemic volume distensibility of the peripheral arm artery reduced with age, with a greater effect at higher external and lower transmural pressures

  16. Influence of affective significance on different levels of processing using pupil dilation in an analogical reasoning task.

    Science.gov (United States)

    Prehn, Kristin; Heekeren, Hauke R; van der Meer, Elke

    2011-02-01

    The present study investigates the interaction of cognition and emotion in decision making, using an analogical reasoning task. In this task, two word pairs were presented simultaneously. Each word pair could be characterized by an associative conceptual relation (object, actor, or location relation) as well as an emotional relation (negative, neutral, or positive valence). Both types of relations were equally task-relevant: Participants had to identify both types of relations, to compare them, and to decide whether or not the word pairs were analogous, i.e., corresponding in both conceptual and emotional relations. Behavioral data showed that emotional relations were identified preferentially and faster than conceptual relations. Pupil dilations reflected the descending difficulty of the conditions and were greatest in amplitude when both conceptual and emotional correspondence was shown, intermediate when only one type of relation (either the emotional or the conceptual) corresponded, and least when neither correspondence existed. Additionally, a negative valence of the word material slowed down response times and increased pupil dilation relative to positive and neutral items. In summary, pupil and response time data together support recent (neurobiological) models concerning the interaction of emotion and cognition by showing that affective significance leads to a processing advantage at a cognitively lower level of information processing (here, identification or retrieval of relations from long-term memory) but can also distract people from higher level cognitive processes (here, from the controlled comparison of retrieved relations). Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Differences in self-regulatory skills among talented athletes: the significance of competitive level and type of sport.

    Science.gov (United States)

    Jonker, Laura; Elferink-Gemser, Marije T; Visscher, Chris

    2010-06-01

    Research has shown that talented athletes outscore their mainstream peers on the basis of self-regulation. Although valuable, this does not tell us more about the distinction between good athletes and the best, which is a prerequisite in talent development. Therefore, we examined the self-regulatory skills of 222 male and female talented athletes aged 12-16 years as a function of competitive sport level (junior international or junior national athletes) and type of sport (individual or team sports). Multivariate analyses of covariance in combination with a discriminant function analysis revealed that "reflection" distinguishes between athletes at the highest levels of excellence. Furthermore, athletes playing individual sports had higher scores on "planning" and "effort" than team sport athletes, highlighting the importance of differences between types of sport. In conclusion, we emphasize the importance of reflection as a self-regulatory skill. Reflection facilitates the development of sport-specific characteristics, which may vary by type of sport. This means that an advanced sense of reflection may help talented athletes to acquire desirable characteristics during their "talent" years to ultimately reach adult elite levels of competition.

  18. Characteristic differences in essential oil composition of six Zanthoxylum bungeanum Maxim. (Rutaceae) cultivars and their biological significance.

    Science.gov (United States)

    Liu, Shu-Ming; Wang, Shi-Jun; Song, Si-Yao; Zou, Yong; Wang, Jun-Ru; Sun, Bing-Yin

    Great variations have been found in composition and content of the essential oil of Zanthoxylum bungeanum Maxim. (Rutaceae), resulting from various factors such as harvest time, drying and extraction methods (Huang et al., 2006; Shao et al., 2013), solvent and herbal parts used (Zhang, 1996; Cao and Zhang, 2010; Wang et al., 2011). However, in terms of artificial introduction and cultivation, there is little research on the chemical composition of essential oil extracted from Z. bungeanum Maxim. cultivars, which have been introduced from different origins. In this study, the composition and content of essential oil from six cultivars (I-VI) have been investigated. They were introduced and cultivated for 11 years in the same cultivation conditions. Cultivars were as followings: Qin'an (I) cultivar originally introduced from Qin'an City in Gansu Province; Dahongpao A (II) from She County in Hebei Province; Dahongpao B (III) from Fuping County; Dahongpao C (IV) from Tongchuan City; Meifengjiao (V) from Feng County; and, Shizitou (VI) from Hancheng City, in Shaanxi Province, China. This research is expected to provide a theoretical basis for further introduction, cultivation, and commercial development of Z. bungeanum Maxim.

  19. Making a difference? Societal entrepreneurship and its significance for a practical theological ecclesiology in a local Western Cape context

    Directory of Open Access Journals (Sweden)

    Ignatius Swart

    2011-10-01

    Full Text Available This article is concerned with the question of whether and how a local church or congregation can, as indissoluble dimension of its vocation as a Christian faith agent, make a difference by influencing the dynamics of social and economic change that are transforming the face and structures of ‘traditional’ social and religious life in its community. Based upon the authors’ own interest in the specific context of the Dutch Reformed congregation of Simondium in the Western Cape and the case study work that they have conducted in this context, an argument about the potential role of this congregation is developed through the conceptual lens of ‘societal entrepreneurship’. After exploring some recent thoughts on this concept in the literature, the authors use the results of their recently conducted case study work to show how the dynamics of a new entrepreneurial drive amongst long-established residents and newcomers in the Simondium region shape the social reality of both the region and the congregation in a forceful way. This insight leads the authors to develop a sociologically and theologically motivated argument about the way in which this changing reality offers newfound opportunities to the Simondium congregation to fulfil its Christian calling. As such, the notion of becoming an ‘entrepreneurial church’ is introduced and a more detailed perspective is offered on those factors that a contextually orientated practical theological ecclesiology should take into account in building the entrepreneurial model in the congregation.

  20. Microstructures and mechanical properties of heat-treated Al–5.0Cu–0.5Fe squeeze cast alloys with different Mn/Fe ratio

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weiwen, E-mail: mewzhang@scut.edu.cn; Lin, Bo; Fan, Jianlei; Zhang, Datong; Li, Yuanyuan

    2013-12-20

    The Al–5.0 wt% Cu–0.5 wt% Fe alloys with different Mn/Fe ratio were prepared by squeeze casting. Various test techniques, including tensile test, image analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), electron probe micro-analyzer (EPMA) and transmission electron microscopy (TEM) were used to examine the microstructures and mechanical properties of the alloys in T5 heat-treated condition. The results show that the β-Fe (Al{sub 7}Cu{sub 2}Fe) is stable and its needle-like morphology is maintained after T5 heat treatment. However, the Chinese script Al{sub m}Fe, α-Fe or Al{sub 6}(FeMn) partially transform to a new Chinese script Cu-rich α(CuFe) (Al{sub 7}Cu{sub 2}Fe or Al{sub 7}Cu{sub 2}(FeMn)), which is harmful to the mechanical properties of the alloys due to the decrease of the Cu content in α(Al) matrix. The optimal Mn/Fe ratio is determined by the morphology of Fe-rich intermetallics, volume fraction of θ′ and T (Al{sub 20}Cu{sub 2}Mn{sub 3}), size of α(Al) dendrite and porosity. Excessive Mn/Fe ratio will deteriorate the mechanical properties of the alloys due to the increase of the total amount of porosity and the Fe-rich intermetallics. When the Mn/Fe ratio is 1.6 and 1.2 for the applied pressure of 0 MPa and 75 MPa, respectively, the needle-like β-Fe phase is completely converted to the Chinese script Fe-rich intermetallics. The ultimate tensile strength, yield strength and elongation of the T5 heat-treated alloy with the Mn/Fe ratio of 1.2 and applied pressure of 75 MPa reach 395 MPa, 335 MPa and 14%, respectively.

  1. Effect of Ni, Fe and Mn in different proportions on microstructure and pollutant-catalyzed properties of Ni-Fe-Mn-O negative temperature coefficient ceramic nanocompositions

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Yonglin, E-mail: leiyonglin@163.com [Engineering Research Center of Biomass Materials, Ministry of Education, School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Lin, Xiaoyan, E-mail: linxy@swust.edu.cn [Engineering Research Center of Biomass Materials, Ministry of Education, School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Liao, Huiwei, E-mail: liaohw@swust.edu.cn [School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China)

    2017-06-15

    The effect of Ni, Fe and Mn in different proportions on microstructure and pollutant-catalyzed properties of Ni-Fe-Mn-O negative temperature coefficient ceramic nanocompositions was studied. Structural and physical characterization of all the samples was carried out by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) method, Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric (TG). The results revealed that the interplanar spacing decreased with increasing Fe content, the grain size decreased with increasing Ni content, the substitution of Ni{sup 2+} in the tetrahedral sites by Fe{sup 2+} increased with increasing Fe content. And increase of iron could improve Ni-Fe-Mn-O high temperature stability. The low-temperature thermal removal efficiencies of 30 mg/L methyl orange solution for NiFeMnO{sub 4}, Ni{sub 0.6}Fe{sub 0.9}Mn{sub 1.5}O{sub 4,} Ni{sub 0.6}Fe{sub 1.8}Mn{sub 0.6}O{sub 4} and Ni{sub 0.3}Fe{sub 2.1}Mn{sub 0.6}O{sub 4} systems were 83.8%, 75.2%, 78.5% and 60.3% at 2400 min, respectively. And the microwave combining with H{sub 2}O{sub 2} removal efficiencies of 30 mg/L methyl orange solution for NiFeMnO{sub 4}, Ni{sub 0.6}Fe{sub 0.9}Mn{sub 1.5}O{sub 4,} Ni{sub 0.6}Fe{sub 1.8}Mn{sub 0.6}O{sub 4} and Ni{sub 0.3}Fe{sub 2.1}Mn{sub 0.6}O{sub 4} systems were 96.5%,93.8%, 98.7% and 98% at 6.0 min, respectively. These results indicated that the Ni-Fe-Mn-O ceramics with appropriate increase of iron were useful for industrial applications on degrading organic pollute. - Highlights: • The relationship of composition and catalytic properties of Ni-Fe-Mn-O was proposed. • The interplanar spacing decreased with increasing Fe content. • The grain size decreased with increasing Ni content. • The substitution of Ni{sup 2+} in the tetrahedral site by Fe{sup 2+} with increasing Fe content.

  2. Microstructure characterization and corrosion resistance properties of Pb-Sb alloys for lead acid battery spine produced by different casting methods

    Science.gov (United States)

    Baig, Muneer; Alam, Mohammad Asif; Alharthi, Nabeel

    2018-01-01

    The aim of this study is to find out the microstructure, hardness, and corrosion resistance of Pb-5%Sb spine alloy. The alloy has been produced by high pressure die casting (HPDC), medium pressure die casting (AS) and low pressure die casting (GS) methods, respectively. The microstructure was characterized by using optical microscopy and scanning electron microscopy (SEM). The hardness was also reported. The corrosion resistance of the spines in 0.5M H2SO4 solution has been analyzed by measuring the weight loss, impedance spectroscopy and the potentiodynamic polarization techniques. It has been found that the spine produced by HPDC has defect-free fine grain structure resulting improvement in hardness and excellent corrosion resistance. PMID:29668709

  3. Role of microstructure in the mean stress dependence of fatigue strength in Ti-6Al-4V alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, S.G.; Cohen, F.S.; Biederman, R.R.; Sisson, R.D. Jr.

    1999-07-01

    The high cycle fatigue properties of Ti-6Al-4V alloy with six different microstructure/texture combinations were investigated. Only materials with lamellar and fine bimodal microstructures exhibited linear Goodman relationship on the constant fatigue life diagram. Materials with coarse bimodal and equiaxed microstructures had anomalous mean stress dependency, with HCF strength at intermediate mean stresses being significantly lower than predicted by Goodman relationship, regardless of whether material was forged or cross-rolled. The role of microstructure in mean stress sensitivity behavior of Ti-6Al-4V is studied. Cyclic strain tests were conducted for all microstructures, and the results of strain-controlled and stress-controlled cyclic tests are compared and discussed.

  4. Garden and Landscape-Scale Correlates of Moths of Differing Conservation Status: Significant Effects of Urbanization and Habitat Diversity

    Science.gov (United States)

    Bates, Adam J.; Sadler, Jon P.; Grundy, Dave; Lowe, Norman; Davis, George; Baker, David; Bridge, Malcolm; Freestone, Roger; Gardner, David; Gibson, Chris; Hemming, Robin; Howarth, Stephen; Orridge, Steve; Shaw, Mark; Tams, Tom; Young, Heather

    2014-01-01

    Moths are abundant and ubiquitous in vegetated terrestrial environments and are pollinators, important herbivores of wild plants, and food for birds, bats and rodents. In recent years, many once abundant and widespread species have shown sharp declines that have been cited by some as indicative of a widespread insect biodiversity crisis. Likely causes of these declines include agricultural intensification, light pollution, climate change, and urbanization; however, the real underlying cause(s) is still open to conjecture. We used data collected from the citizen science Garden Moth Scheme (GMS) to explore the spatial association between the abundance of 195 widespread British species of moth, and garden habitat and landscape features, to see if spatial habitat and landscape associations varied for species of differing conservation status. We found that associations with habitat and landscape composition were species-specific, but that there were consistent trends in species richness and total moth abundance. Gardens with more diverse and extensive microhabitats were associated with higher species richness and moth abundance; gardens near to the coast were associated with higher richness and moth abundance; and gardens in more urbanized locations were associated with lower species richness and moth abundance. The same trends were also found for species classified as increasing, declining and vulnerable under IUCN (World Conservation Union) criteria. However, vulnerable species were more strongly negatively affected by urbanization than increasing species. Two hypotheses are proposed to explain this observation: (1) that the underlying factors causing declines in vulnerable species (e.g., possibilities include fragmentation, habitat deterioration, agrochemical pollution) across Britain are the same in urban areas, but that these deleterious effects are more intense in urban areas; and/or (2) that urban areas can act as ecological traps for some vulnerable species of

  5. Different surgical strategies for chronic pancreatitis significantly improve long-term outcome: a comparative single center study

    Directory of Open Access Journals (Sweden)

    Hildebrand P

    2010-08-01

    Full Text Available Abstract Objective In general, chronic pancreatitis (CP primarily requires conservative treatment. The chronic pain syndrome and complications make patients seek surgical advice, frequently after years of progression. In the past, surgical procedures involving drainage as well as resection have been employed successfully. The present study compared the different surgical strategies. Patients and Methods From March 2000 until April 2005, a total of 51 patients underwent surgical treatment for CP at the Department of surgery, University of Schleswig-Holstein, Campus Lübeck. Out of those 51 patients, 39 (76.5% were operated according to the Frey procedure, and in 12 cases (23.5% the Whipple procedure was performed. Patient data were documented prospectively throughout the duration of the hospital stay. The evaluation of the postoperative pain score was carried out retrospectively with a validated questionnaire. Results Average operating time was 240 minutes for the Frey group and 411 minutes for the Whipple group. The medium number of blood transfusions was 1 in the Frey group and 4.5 in the Whipple group. Overall morbidity was 21% in the Frey group and 42% in the Whipple group. 30-day mortality was zero for all patients. During the median follow-up period of 50 months, an improvement in pain score was observed in 93% of the patients of the Frey group and 67% of the patients treated according to the Whipple procedure. Conclusion The results show that both the Frey procedure as well as partial pancreaticoduodenectomy are capable of improving chronic pain symptoms in CP. As far as later endocrine and exocrine pancreatic insufficiency is concerned, however, the extended drainage operation according to Frey proves to be advantageous compared to the traditional resection procedure by Whipple. Accordingly, the Frey procedure provides us with an organ-preserving surgical procedure which treats the complications of CP sufficiently, thus being an

  6. Garden and landscape-scale correlates of moths of differing conservation status: significant effects of urbanization and habitat diversity.

    Directory of Open Access Journals (Sweden)

    Adam J Bates

    Full Text Available Moths are abundant and ubiquitous in vegetated terrestrial environments and are pollinators, important herbivores of wild plants, and food for birds, bats and rodents. In recent years, many once abundant and widespread species have shown sharp declines that have been cited by some as indicative of a widespread insect biodiversity crisis. Likely causes of these declines include agricultural intensification, light pollution, climate change, and urbanization; however, the real underlying cause(s is still open to conjecture. We used data collected from the citizen science Garden Moth Scheme (GMS to explore the spatial association between the abundance of 195 widespread British species of moth, and garden habitat and landscape features, to see if spatial habitat and landscape associations varied for species of differing conservation status. We found that associations with habitat and landscape composition were species-specific, but that there were consistent trends in species richness and total moth abundance. Gardens with more diverse and extensive microhabitats were associated with higher species richness and moth abundance; gardens near to the coast were associated with higher richness and moth abundance; and gardens in more urbanized locations were associated with lower species richness and moth abundance. The same trends were also found for species classified as increasing, declining and vulnerable under IUCN (World Conservation Union criteria. However, vulnerable species were more strongly negatively affected by urbanization than increasing species. Two hypotheses are proposed to explain this observation: (1 that the underlying factors causing declines in vulnerable species (e.g., possibilities include fragmentation, habitat deterioration, agrochemical pollution across Britain are the same in urban areas, but that these deleterious effects are more intense in urban areas; and/or (2 that urban areas can act as ecological traps for some

  7. Significance and function of different spinal collateral compartments following thoracic aortic surgery: immediate versus long-term flow compensation.

    Science.gov (United States)

    Meffert, Philipp; Bischoff, Moritz S; Brenner, Robert; Siepe, Matthias; Beyersdorf, Friedhelm; Kari, Fabian A

    2014-05-01

    Iatrogenic paraplegia has been accompanying cardiovascular surgery since its beginning. As a result, surgeons have been developing many theories about the exact mechanisms of this devastating complication. Thus, the impact of single arteries that contribute to the spinal perfusion is one of the most discussed subjects in modern surgery. The subsequent decision of reattachment or the permanent disconnection of these intercostal arteries divides the surgical community. On the one hand, the anatomical or vascular approach pleads for the immediate reimplantation to reconstruct the anatomical situation. On the other hand, the decision of the permanent disconnection aims at avoiding stealing phenomenon away from the spinal vascular network. This spinal collateral network can be described as consisting of three components-the intraspinal and two paraspinal compartments-that feed the nutrient arteries of the spinal cord. The exact functional impact of the different compartments of the collateral network remains poorly understood. In this review, the function of the intraspinal compartment in the context of collateral network principle as an immediate emergency backup system is described. The exact structure and architectural principles of the intraspinal compartment are described. The critical parameters with regard to the risk of postoperative spinal cord ischaemia are the number of anterior radiculomedullary arteries (ARMAs) and the distance between them in relation to the longitudinal extent of aortic disease. The paraspinal network as a sleeping reserve is proposed as the long-term backup system. This sleeping reserve has to be activated by arteriogenic stimuli. These are presented briefly, and prior findings regarding arteriogenesis are discussed in the light of the collateral network concept. Finally, the role of preoperative visualization of the ARMAs in order to evaluate the risk of postoperative paraplegia is emphasized.

  8. Microstructure of rapidly solidified materials

    Science.gov (United States)

    Jones, H.

    1984-07-01

    The basic features of rapidly solidified microstructures are described and differences arising from alternative processing strategies are discussed. The possibility of achieving substantial undercooling prior to solidification in processes such as quench atomization and chill block melt spinning can give rise to striking microstructural transitions even when external heat extraction is nominally Newtonian. The increased opportunity in laser and electron beam surface melting for epitaxial growth on the parent solid at an accelerating rate, however, does not exclude the formation of nonequilibrium phases since the required undercooling can be locally attained at the solidification front which is itself advancing at a sufficiently high velocity. The effects of fluid flow indicated particularly in melt spinning and surface melting are additional to the transformational and heat flow considerations that form the present basis for interpretation of such microstructural effects.

  9. Lithology, microstructures, fluid inclusions, and geochemistry of rock salt and of the cap-rock contact in Oakwood Dome, East Texas: significance for nuclear waste storage. Report of investigations No. 120

    International Nuclear Information System (INIS)

    Dix, O.R.; Jackson, M.P.A.

    1982-01-01

    Oakwood salt dome in Leon and Freestone Counties, Texas, has a core composed of a diapiric salt stock at a depth of 355 m. A vertical borehole in the center of the salt stock yielded 57.3 m of continuous rock-salt core overlain by 137 m of anhydrite-calcite cap rock. The lower 55.3 m of rock salt exhibits a strong, penetrative schistosity and parallel cleavage dipping at 30 to 40 0 and more than 60 variably dipping layers of disseminated anhydrite. Anhydrite constitutes 1.3 +- 0.7 percent of the rock-salt core. The upper 2 m of rock salt is unfoliated, comprising a lower 1.4-m interval of medium-grained granoblastic rock salt and an upper 0.6-m interval of coarse-grained granoblastic rock salt. An abrupt, cavity-free contact separates rock salt from laminated cap rock consisting of granoblastic-polygonal anhydrite virtually devoid of halite or pore space. Microstructures and concentration gradients of fluid inclusions suggest that the unfoliated rock salt at the crest of the salt stock was once strongly foliated, but that this fabric was destroyed by solid-state recrystallization. Downward movement of brine from the rock-salt - cap-rock contact was apparently accompanied by two recrystallization fronts. Dissolution of halite at the contact released disseminated anhydrite that presumably accumulated as sand on the floor of the dissolution cavity. Renewed rise of the salt stock closed the cavity, and the anhydrite sand was accreted against the base of the cap rock. Much, if not all, of the lamination in the 80 m of anhydrite cap rock may result from cycles of dissolution, recrystallization, and upward movement in the salt stock, followed by accretion of anhydrite residuum as laminae against the base of the cap rock. These processes, which are strongly influenced by fluids, act both to breach waste repositories and to geologically isolate them

  10. Superfund explanation of significant difference for the record of decision (EPA Region 3): Westinghouse Elevator Company Plant, Gettysburg, PA, August 3, 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    The document explains significant differences to the remedy selected in the Record of Decision (ROD) for the Site signed by the Regional Administrator on June 30, 1992 (PB93-963911) for Operable Unit 1. The Significant Difference between the remedy presented in the June 30, 1992 ROD and the changes to the ROD that will be implemented are explained.

  11. MR-based trabecular bone microstructure is not altered in subjects with indolent systemic mastocytosis.

    Science.gov (United States)

    Baum, Thomas; Karampinos, Dimitrios C; Brockow, Knut; Seifert-Klauss, Vanadin; Jungmann, Pia M; Biedermann, Tilo; Rummeny, Ernst J; Bauer, Jan S; Müller, Dirk

    2015-01-01

    Subjects with indolent systemic mastocytosis (ISM) have an increased risk for osteoporosis. It has been demonstrated that trabecular bone microstructure analysis improves the prediction of bone strength beyond dual-energy X-ray absorptiometry-based bone mineral density. The purpose of this study was to obtain Magnetic Resonance (MR)-based trabecular bone microstructure parameters as advanced imaging biomarkers in subjects with ISM (n=18) and compare them with those of normal controls (n=18). Trabecular bone microstructure parameters were not significantly (P>.05) different between subjects with ISM and controls. These findings revealed important pathophysiological information about ISM-associated osteoporosis and may limit the use of trabecular bone microstructure analysis in this clinical setting. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Dietary analysis of Late Cenozoic Mexican equids from three different geographic/geologic settings using stable carbon isotopes: Coincidences, differences and paleobiologic significance

    Science.gov (United States)

    Pérez-Crespo, Víctor Adrian; Ferrusquía-Villafranca, Ismael; Bravo-Cuevas, Víctor Manuel; Morales-Puente, Pedro; Ruiz-González, José E.

    2016-03-01

    The development of Vertebrate Paleontology in Mexico is uneven, so that there is a strong bias in favor of Neogene/Quaternary mammals largely collected in the Trans-Mexican Volcanic Belt (TMVB hereafter) and Central Plateau (CeP hereafter) Morphotectonic Provinces [MP hereafter]; however, the time is ripe for pursuing research in other than taxonomic areas. Here we investigate C3/C4 plant consumption in the equid lineage in three such provinces, which provide different geographic/geologic and paleoecologic scenarios during the Barstovian, Hemphillian and Rancholabrean times. Our results show that the Barstovian equids from Oaxaca, Sierra Madre del Sur MP Cormohipparion aff. C. quinni, Merychippus cf. M. sejunctus and Pliohippus sp. largely fed on C3 plants, which were the chief food stuff of horses in Mexico, particularly in the Southeast. On the other hand, the Hemphillian equid from Guanajuato, CeP Astrohippus stocki, was an unbalanced C3/C4 mixed feeders in favor of C4 plants, a fact that indicates a profound plant diversification due to the inception and rapid diversification of C4 plants that occurred there at this time, as it occurred in temperate North America, resulting in the differential consumption of C4 plants over that of C3 plants. Such trend prevailed until the Rancholabrean, as born out by the inferred diet for Equus conversidens and Equus sp. from Hidalgo, TMVB. Clearly then, the coeval diet change observed in Mexico and temperate North America implies a correlative vegetation change resulting in the appearance and rapid diversification of C4 plants, which largely formed the preferred food stuff of equids since the Hemphillian, although some C3 plant consumption was maintained till the Rancholabrean. It should be noted that the development of hypsodonty in equids and many artiodactyls, has long been interpreted as the adaptive mammalian response to the new feeding conditions.

  13. TEM investigations of microstructures of combustion aerosols

    International Nuclear Information System (INIS)

    Marquardt, A.; Hackfort, H.; Borchardt, J.; Schober, T.; Friedrich, J.

    1992-12-01

    In the incineration of organic material, apart from a series of gaseous pollutants, particulate pollutants or combustion aerosols also arise. The latter frequently consist of particles with a solid core of carbon to which a large number of inorganic and organic compounds are attached. These primarily include the polycyclic aromatic hydrocarbons (PAH) and their nitro-derivatives (NPAH), whose mutagenic or carcinogenic effect is known. The invisible particle sizes in the nanometer range, whose retention in the incineration off-gas is not state of the art, are of increasing significance for man and environment. On the one hand, they are deposited almost completely in the human lung. On the other hand, due to their fine dispersity they have along residence time in the atmosphere where they participate in chemical reactions and climatically significant processes. Important insights about the formation process of combustion aerosols are to be expected from the imaging of their microstructures in the transmission electron microscope (TEM). The present contribution describes the development and application of a representative sampling procedure for aerosols from a partial flow of flue gas from a fluidized-bed furnace. The method developed consists of electrically charging aerosol particles in situ and subsequently selectively precipitating them onto a microscope slide in an electric field. TEM studies of aerosol microstructures on the microscope slides revealed that in the combustion of petrol and heating oil under different combustion conditions in principle the same particle structures result, whereas in the incineration of used lubricating oil quite different particle structures were found. Results from the literature on aerosol microstructures in exhaust gases from petrol and diesel engines demonstrate agreement with the results of this study in the basic structure of the particles. (orig.) [de

  14. Creep of Two-Phase Microstructures for Microelectronic Applications

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Heidi Linch [Univ. of California, Berkeley, CA (United States)

    1998-12-01

    The mechanical properties of low-melting temperature alloys are highly influenced by their creep behavior. This study investigates the dominant mechanisms that control creep behavior of two-phase, low-melting temperature alloys as a function of microstructure. The alloy systems selected for study were In-Ag and Sn-Bi because their eutectic compositions represent distinctly different microstructure.” The In-Ag eutectic contains a discontinuous phase while the Sn-Bi eutectic consists of two continuous phases. In addition, this work generates useful engineering data on Pb-free alloys with a joint specimen geometry that simulates microstructure found in microelectronic applications. The use of joint test specimens allows for observations regarding the practical attainability of superplastic microstructure in real solder joints by varying the cooling rate. Steady-state creep properties of In-Ag eutectic, Sn-Bi eutectic, Sn-xBi solid-solution and pure Bi joints have been measured using constant load tests at temperatures ranging from O°C to 90°C. Constitutive equations are derived to describe the steady-state creep behavior for In-Ageutectic solder joints and Sn-xBi solid-solution joints. The data are well represented by an equation of the form proposed by Dom: a power-law equation applies to each independent creep mechanism. Rate-controlling creep mechanisms, as a function of applied shear stress, test temperature, and joint microstructure, are discussed. Literature data on the steady-state creep properties of Sn-Bi eutectic are reviewed and compared with the Sn-xBi solid-solution and pure Bi joint data measured in the current study. The role of constituent phases in controlling eutectic creep behavior is discussed for both alloy systems. In general, for continuous, two-phase microstructure, where each phase exhibits significantly different creep behavior, the harder or more creep resistant phase will dominate the creep behavior in a lamellar microstructure. If a

  15. Performance degradation and microstructure changes in freeze-thaw cycling for PEMFC MEAs with various initial microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Yeop; Kim, Hyoung-Juhn; Cho, EunAe; Lee, Kug-Seung; Lim, Tae-Hoon; Jang, Jong Hyun [Fuel Cell Center, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Hwang, In Chul [Corporate Research and Development Division, Hyundai-Kia Motors, Gyeonggi-do 446-912 (Korea, Republic of)

    2010-12-15

    When the temperature of a fuel cell vehicle is repeatedly reduced to subzero temperatures, volume changes by water/ice transformations and frost heave mechanism can cause microstructural changes in membrane-electrode assemblies (MEA), and a resultant permanent decrease in the performance of fuel cell stacks. In this study, five MEAs manufactured by different methods, were tested under repeated freeze-thaw (F-T) cycles between -20 C and 10 C, and the variations in their electrochemical and microstructural characteristics were analyzed according to the initial microstructures. When the MEAs were prepared by spraying catalyst inks on polymer membranes, no significant microstructural changes were observed. In the case of two supplied MEAs, void formations at the electrolyte/electrode interface or vertical cracks within the catalyst layers were observed after 120 F-T cycles. Void formation seems to be responsible for performance degradation as a result of ohmic loss, but the effect of cracks in the catalyst layers was not confirmed. In 120 F-T cycles, activation overpotentials and concentration overpotentials did not increase significantly for any of the MEAs, even although gradual decreases in the electrochemically active surface area of the platinum catalysts and changes in the porous structure were observed. (author)

  16. Microstructure evolution and mechanical properties of a particulate reinforced magnesium matrix composites forged at elevated temperatures

    International Nuclear Information System (INIS)

    Deng, K.K.; Wu, K.; Wang, X.J.; Wu, Y.W.; Hu, X.S.; Zheng, M.Y.; Gan, W.M.; Brokmeier, H.G.

    2010-01-01

    SiCp/AZ91 magnesium matrix composite was fabricated by stir casting. The as-cast ingots were cut into cylindrical billets, and then forged at different temperatures (320, 370, 420, 470 and 520 deg. C) at a constant RAM speed of 15 mm/s with 50% reduction. The microstructure evolution of the composites during forging was investigated by optical microscope, scanning electron microscope, and transmission electron microscope. The texture of the forged composites was measured by neutron diffraction. Mechanical properties of the composite at different forging temperatures were tested by tensile tests at room temperature. It was found that a strong basal plane texture formed during forging, and the intensity of basal plane texture weakened as forging temperatures increased. The particle distribution in the composite was significantly improved by hot forging. Typical microstructures were obtained after forging at different temperatures and the composite with different microstructures offered different mechanical properties during tensile test.

  17. Microstructure evolution of the Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4} joints brazed using Au-Ni-V filler alloys with different V content

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhang, J., E-mail: hitzhangjie@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhang, H.W.; Fan, G.H.; He, Y.M. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-08-18

    Highlights: > Si{sub 3}N{sub 4} ceramic was brazed using Au-Ni-V filler alloy with different V content. > The microstructure evolution of the joint was study in detail in the paper. > The polygonal Ni{sub 2}SiV{sub 3} and Ni{sub 3}V phase in the joint were investigated by TEM. > The formation of different compounds and alloys in joint was detailed discussed. - Abstract: Au-Ni-V filler alloys with different vanadium contents were designed to braze Si{sub 3}N{sub 4} ceramic at 1373 K for 30 min, and the microstructures of brazing seams were investigated by SEM and TEM. When the Au-Ni-V filler alloy contains 5 at.% V, round-like Ni[Si, V, Au] precipitates form in the Au[Ni] solid solution matrix and a VN reaction layer with 0.5 {mu}m thickness appears on Si{sub 3}N{sub 4} interface. When the V content increases to 10 at.%, a new polygonal Ni{sub 2}SiV{sub 3} phase occurs in the seam, and the Ni[Si, V, Au] precipitate coarsens and VN layer thickens. With increase of V contents to 15 and 20 at.%, laminar Ni[Au] and polygonal Ni{sub 3}V precipitates form. With 25 at.% V content in the filler alloy, the Ni{sub 2}SiV{sub 3} and Ni{sub 3}V precipitates distribute homogenously in the brazing seam. These microstructure evolutions were attributed to the reaction between Si{sub 3}N{sub 4} and vanadium, which forms VN reaction layer and releases Si into the molten alloy.

  18. Autonomous patterning of cells on microstructured fine particles

    International Nuclear Information System (INIS)

    Takeda, Iwori; Kawanabe, Masato; Kaneko, Arata

    2015-01-01

    Regularly patterned cells can clarify cellular function and are required in some biochip applications. This study examines cell patterning along microstructures and the effect of microstructural geometry on selective cellular adhesion. Particles can be autonomously assembled on a soda-lime glass substrate that is chemically patterned by immersion in a suspension of fine particles. By adopting various sizes of fine particles, we can control the geometry of the microstructure. Cells adhere more readily to microstructured fine particles than to flat glass substrate. Silica particles hexagonally packed in 5–40 μm line and space microstructures provide an effective cell scaffold on the glass substrate. Cultured cells tend to attach and proliferate along the microstructured region while avoiding the flat region. The difference in cell adhesion is attributed to their geometries, as both of the silica particles and soda-lime glass are hydrophilic related with cell adhesiveness. After cell seeding, cells adhered to the flat region migrated toward the microstructured region. For most of the cells to assemble on the scaffold, the scaffolding microstructures must be spaced by at most 65 μm. - Highlights: • PS and SiO 2 particles provide effective scaffolds for cells. • Cells that adhere to microstructured particles successfully proliferate and differentiate. • Selective adhesion and growth along the scaffold can be achieved by patterning the fine particle microstructure. • Cells adhered to flat regions migrate toward microstructured regions. • Selective adhesion by cells depends on the microstructural geometry; specifically, on the inter-line spacing

  19. Morphology and microstructure of composite materials

    Science.gov (United States)

    Tiwari, S. N.; Srinivansan, K.

    1991-01-01

    Lightweight continuous carbon fiber based polymeric composites are currently enjoying increasing acceptance as structural materials capable of replacing metals and alloys in load bearing applications. As with most new materials, these composites are undergoing trials with several competing processing techniques aimed at cost effectively producing void free consolidations with good mechanical properties. As metallic materials have been in use for several centuries, a considerable database exists on their morphology - microstructure; and the interrelationships between structure and properties have been well documented. Numerous studies on composites have established the crucial relationship between microstructure - morphology and properties. The various microstructural and morphological features of composite materials, particularly those accompanying different processing routes, are documented.

  20. Effect of mode of rolling on development of texture and microstructure in two-phase (α + β) brass

    International Nuclear Information System (INIS)

    Garg, Rohini; Ranganathan, S.; Suwas, Satyam

    2010-01-01

    The evolution of microstructure and texture during deformation of two-phase (α + β) brass was studied for different initial microstructure and texture. The deformation processing involved unidirectional and multi-step cross-rolling. The bulk textures were determined by measuring the pole figures and calculating the orientation distribution function ODF for both α (fcc) and β (bcc) phases, while the microstructure and other microstructural parameters were measured through optical microscopy and scanning electron microscopy with electron back scatter diffraction (SEM-EBSD). Results indicate that textures developed after unidirectional rolling and multi-step cross-rolling are significantly different. The variation in initial texture had a pronounced effect on the development of texture in the α phase during subsequent deformation.

  1. Effect of mode of rolling on development of texture and microstructure in two-phase ({alpha} + {beta}) brass

    Energy Technology Data Exchange (ETDEWEB)

    Garg, Rohini; Ranganathan, S. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India); Suwas, Satyam, E-mail: satyamsuwas@met.iisc.ernet.in [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India)

    2010-07-15

    The evolution of microstructure and texture during deformation of two-phase ({alpha} + {beta}) brass was studied for different initial microstructure and texture. The deformation processing involved unidirectional and multi-step cross-rolling. The bulk textures were determined by measuring the pole figures and calculating the orientation distribution function ODF for both {alpha} (fcc) and {beta} (bcc) phases, while the microstructure and other microstructural parameters were measured through optical microscopy and scanning electron microscopy with electron back scatter diffraction (SEM-EBSD). Results indicate that textures developed after unidirectional rolling and multi-step cross-rolling are significantly different. The variation in initial texture had a pronounced effect on the development of texture in the {alpha} phase during subsequent deformation.

  2. Study of PM2000 microstructure evolution following FSW process

    International Nuclear Information System (INIS)

    Mathon, M.H.; Klosek, V.; Carlan, Y. de; Forest, L.

    2009-01-01

    The materials reinforced by oxides dispersion, usually called ODS (Oxide Strengthened Dispersion), have a vast applicability because of their excellent mechanical resistance at medium and high temperatures. Their weldability is one of the technological issue which remain today. The Friction Stir Welding process is a means of welding which would make it possible to preserve the oxides dispersion in the metal matrix. As a solid-state joint process, Friction Stir Welding (FSW) joins metals by locally introducing frictional heat and plastic flow by rotation of the welding tool with resulting local microstructure changes. The local microstructure determines the weld mechanical properties. Therefore, it is important to investigate the relationship between the microstructure and the mechanical properties. In this work, the PM2000 steel microstructure in friction stir (FS) weld was studied by neutron scattering. The oxides size distribution evolution between the bulk and the weld was analyzed by SANS. Crystallographic texture variations during friction stir processing were investigated by neutron diffraction. Indeed, heating and severe plastic deformation can significantly alter the original texture and then affect the physical and mechanical properties. The texture was studied in different zones: in the bulk, in the thermo-mechanically affected zone (TMAZ) and is the heat-affected zone (HAZ) of the PM2000 alloy. Lastly, the stresses distribution after welding is a crucial parameter for the mechanical properties. Their variation prediction under FSW, taking into account of the microstructure evolution which occur during the process, is very delicate. The neutron diffraction allowed characterizing the distribution of the stresses in the different zones.

  3. Relative effects of chromium and niobium on microstructure and mechanical properties as a function of oxygen content in TiAl alloys

    International Nuclear Information System (INIS)

    Lamirand, M.; Bonnentien, J.-L.; Ferriere, G.; Guerin, S.; Chevalier, J.-P.

    2007-01-01

    The effects of 2 at.% chromium and niobium on microstructure and mechanical properties of Ti-48Al-x(Cr, Nb) have been investigated for alloys with different oxygen content, ranging from ultra-high purity to doped alloys. Chromium and niobium additions have significant effects for the high purity alloys, whereas for alloys containing oxygen, no significant modification is observed due to the strong stabilizing effect of oxygen on the lamellar microstructure

  4. Chalcogenide glass hollow core microstructured optical fibers

    Directory of Open Access Journals (Sweden)

    Vladimir S. eShiryaev

    2015-03-01

    Full Text Available The recent developments on chalcogenide glass hollow core microstructured optical fibers (HC-MOFs are presented. The comparative analysis of simulated optical properties for chalcogenide HC-MOFs of negative-curvature with different size and number of capillaries is given. The technique for the manufacture of microstructured chalcogenide preforms, which includes the assembly of the substrate glass tube and 8-10 capillaries, is described. Further trends to improve the optical transmission in chalcogenide NCHCFs are considered.

  5. Quality of Life for Individuals with Hearing Impairment Who Have Not Consulted for Services and Their Significant Others: Same- and Different-Sex Couples

    Science.gov (United States)

    Kelly, Rebecca J.; Atcherson, Samuel R.

    2011-01-01

    The purpose of this exploratory study was to assess perceptions of quality of life for individuals with hearing impairment who have not consulted for services and their significant others who are in same-sex relationships vs. those who are in different-sex relationships. Data were collected on a total of 20 older couples: 10 in same-sex…

  6. Stochastic model for the 3D microstructure of pristine and cyclically aged cathodes in Li-ion batteries

    Science.gov (United States)

    Kuchler, Klaus; Westhoff, Daniel; Feinauer, Julian; Mitsch, Tim; Manke, Ingo; Schmidt, Volker

    2018-04-01

    It is well-known that the microstructure of electrodes in lithium-ion batteries strongly affects their performance. Vice versa, the microstructure can exhibit strong changes during the usage of the battery due to aging effects. For a better understanding of these effects, mathematical analysis and modeling has turned out to be of great help. In particular, stochastic 3D microstructure models have proven to be a powerful and very flexible tool to generate various kinds of particle-based structures. Recently, such models have been proposed for the microstructure of anodes in lithium-ion energy and power cells. In the present paper, we describe a stochastic modeling approach for the 3D microstructure of cathodes in a lithium-ion energy cell, which differs significantly from the one observed in anodes. The model for the cathode data enhances the ideas of the anode models, which have been developed so far. It is calibrated using 3D tomographic image data from pristine as well as two aged cathodes. A validation based on morphological image characteristics shows that the model is able to realistically describe both, the microstructure of pristine and aged cathodes. Thus, we conclude that the model is suitable to generate virtual, but realistic microstructures of lithium-ion cathodes.

  7. Surface microstructure replication in injection molding

    DEFF Research Database (Denmark)

    Theilade, Uffe Arlø; Hansen, Hans Nørgaard

    2006-01-01

    topography is transcribed onto the plastic part through complex mechanisms. This replication, however, is not perfect, and the replication quality depends on the plastic material properties, the topography itself, and the process conditions. This paper describes and discusses an investigation of injection...... molding of surface microstructures. The fundamental problem of surface microstructure replication has been studied. The research is based on specific microstructures as found in lab-on-a-chip products and on rough surfaces generated from EDM (electro discharge machining) mold cavities. Emphasis is put...... on the ability to replicate surface microstructures under normal injection-molding conditions, i.e., with commodity materials within typical process windows. It was found that within typical process windows the replication quality depends significantly on several process parameters, and especially the mold...

  8. Microstructural characterization of stainless steel 17-4 PH used in the control element of PWR-Type reactors submitted to different heat treatments

    International Nuclear Information System (INIS)

    Ferreira, Douglas F.A.; Rezende, Renato P.; Turcarelli, Tiago

    2017-01-01

    The Control Element is a set of mechanical components of pressurized water cooled nuclear reactors (PWR), with the function of modifying the reactivity of the nucleus by insertion and withdrawal of neutron absorptive rod, in order to change the flow of neutrons (power) to the necessary and desired levels. The control element also has a safety function when there is a need to have negative reactivity available to shut down the reactor in normal operating or accident situations. In this situation, the control element descends instantly and inserts the rods with absorptive material into the fuel element thus shutting down the reactor. The control element consists of control rods, which carry the neutron absorption material and is supported by the spider, pin, spring and spring retainer assembly. The control element has some components that need to have high resistance to impacts when the safety function is activated, so the material of this component must have high mechanical strength and toughness. One of the materials in which can be specified for this application is martensitic stainless steel 17- 4PH (UNS 17400). This steel, when subjected to the aging heat treatment, has its mechanical properties altered due to the precipitation of dispersed intermetallic compounds in the matrix. In all heat treatments performed the predominant microstructure is lath martensite. The heat treatment of the 620 °C / 4 h presented lower hardness when compared to the other treatments and when increase time and temperature the material presents Nb precipitates that increase the hardness. (author)

  9. Microstructural characterization of stainless steel 17-4 PH used in the control element of PWR-Type reactors submitted to different heat treatments

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Douglas F.A.; Rezende, Renato P.; Turcarelli, Tiago, E-mail: ferreira@marinha.mil.br, E-mail: renato.rezende@marinha.mil.br, E-mail: tiago.turcarelli@marinha.mil.br [Centro Tecnológico da Marinha em São Paulo (DDNM/CTMSP), São Paulo, SP (Brazil). Diretoria de Desenvolvimento Nuclear da Marinha

    2017-07-01

    The Control Element is a set of mechanical components of pressurized water cooled nuclear reactors (PWR), with the function of modifying the reactivity of the nucleus by insertion and withdrawal of neutron absorptive rod, in order to change the flow of neutrons (power) to the necessary and desired levels. The control element also has a safety function when there is a need to have negative reactivity available to shut down the reactor in normal operating or accident situations. In this situation, the control element descends instantly and inserts the rods with absorptive material into the fuel element thus shutting down the reactor. The control element consists of control rods, which carry the neutron absorption material and is supported by the spider, pin, spring and spring retainer assembly. The control element has some components that need to have high resistance to impacts when the safety function is activated, so the material of this component must have high mechanical strength and toughness. One of the materials in which can be specified for this application is martensitic stainless steel 17- 4PH (UNS 17400). This steel, when subjected to the aging heat treatment, has its mechanical properties altered due to the precipitation of dispersed intermetallic compounds in the matrix. In all heat treatments performed the predominant microstructure is lath martensite. The heat treatment of the 620 °C / 4 h presented lower hardness when compared to the other treatments and when increase time and temperature the material presents Nb precipitates that increase the hardness. (author)

  10. Microstructure, martensitic transformation, mechanical and shape memory properties of Ni–Co–Mn–In high-temperature shape memory alloys under different heat treatments

    International Nuclear Information System (INIS)

    Yang, Shuiyuan; Wang, Cuiping; Shi, Zhan; Wang, Jinming; Zhang, Jinbin; Huang, Yixiong; Liu, Xingjun

    2016-01-01

    The microstructure, martensitic transformation behavior, mechanical and shape memory properties of Ni 40 Co 10 Mn 41+x In 9−x (x=0, 2 and 4) high-temperature shape memory alloys annealed at 900 °C for 24 h or at 800 °C for 2 h were investigated, respectively. The tetragonal martensite phase and fcc γ phase are observed in all the studied alloys. The reversible martensitic transformation temperatures of the alloys increase with the increases of the electron concentration and the tetragonality of martensite phase. The amount of γ phase gradually increases with the decrease of In content, and much more γ phase in the alloys annealed at 900 °C results in slightly larger compressive fracture strain. Although the alloys with x=0 and 2 have a mass of γ phase, they still exhibit good shape memory properties. The amount of γ phase reaches about 20% in the alloy with x=0 after annealed at 900 °C, but a full recovery strain of 3.6% and a two-way shape memory effect of 0.8% can be obtained after two thermomechanical cycles.

  11. Microstructure, mechanical properties, biocorrosion behavior, and cytotoxicity of as-extruded Mg-Nd-Zn-Zr alloy with different extrusion ratios.

    Science.gov (United States)

    Zhang, Xiaobo; Yuan, Guangyin; Niu, Jialin; Fu, Penghuai; Ding, Wenjiang

    2012-05-01

    Recently, commercial magnesium (Mg) alloys containing Al (such as AZ31 and AZ91) or Y (such as WE43) have been studied extensively for biomedical applications. However, these Mg alloys were developed as structural materials, not as biomaterials. In this study, a patented Mg-Nd-Zn-Zr (denoted as JDBM) alloy was investigated as a biomedical material. The microstructure, mechanical properties, biocorrosion behavior, and cytotoxicity of the alloy extruded at 320 °C with extrusion ratios of 8 and 25 were studied. The results show that the lower extrusion ratio results in finer grains and higher strength, but lower elongation, while the higher extrusion ratio results in coarser grains and lower strength, but higher elongation. The biocorrosion behavior of the alloy was investigated by hydrogen evolution and mass loss tests in simulated body fluid (SBF). The results show that the alloy extruded with lower extrusion ratio exhibits better corrosion resistance. The corrosion mode of the alloy is uniform corrosion, which is favorable for biomedical applications. Aging treatment on the as-extruded alloy improves the strength and decreases the elongation at room temperature, and has a small positive influence on the corrosion resistance in SBF. The cytotoxicity test indicates that the as-extruded JDBM alloy meets the requirement of cell toxicity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Differences observed in the surface morphology and microstructure of Ni-Fe-Cu ternary thin films electrochemically deposited at low and high applied current densities

    International Nuclear Information System (INIS)

    Sarac, U; Kaya, M; Baykul, M C

    2016-01-01

    In this research, nanocrystalline Ni-Fe-Cu ternary thin films using electrochemical deposition technique were produced at low and high applied current densities onto Indium Tin Oxide (ITO) coated conducting glass substrates. Change of surface morphology and microstructural properties of the films were investigated. Energy dispersive X-ray spectroscopy (EDX) measurements showed that the Ni-Fe-Cu ternary thin films exhibit anomalous codeposition behaviour during the electrochemical deposition process. From the X-ray diffraction (XRD) analyses, it was revealed that there are two segregated phases such as Cu- rich and Ni-rich within the films. The crystallographic structure of the films was face-centered cubic (FCC). It was also observed that the film has lower lattice micro-strain and higher texture degree at high applied current density. Scanning electron microscopy (SEM) studies revealed that the films have rounded shape particles on the base part and cauliflower-like structures on the upper part. The film electrodeposited at high current density had considerably smaller rounded shape particles and cauliflower-like structures. From the atomic force microscopy (AFM) analyses, it was shown that the film deposited at high current density has smaller particle size and surface roughness than the film grown at low current density. (paper)

  13. Alteration of alkali reactive aggregates autoclaved in different alkali solutions and application to alkali-aggregate reaction in concrete (II) expansion and microstructure of concrete microbar

    International Nuclear Information System (INIS)

    Lu Duyou; Mei Laibao; Xu Zhongzi; Tang Mingshu; Mo Xiangyin; Fournier, Benoit

    2006-01-01

    The effect of the type of alkalis on the expansion behavior of concrete microbars containing typical aggregate with alkali-silica reactivity and alkali-carbonate reactivity was studied. The results verified that: (1) at the same molar concentration, sodium has the strongest contribution to expansion due to both ASR and ACR, followed by potassium and lithium; (2) sufficient LiOH can completely suppress expansion due to ASR whereas it can induce expansion due to ACR. It is possible to use the duplex effect of LiOH on ASR and ACR to clarify the ACR contribution when ASR and ACR may coexist. It has been shown that a small amount of dolomite in the fine-grained siliceous Spratt limestone, which has always been used as a reference aggregate for high alkali-silica reactivity, might dedolomitize in alkaline environment and contribute to the expansion. That is to say, Spratt limestone may exhibit both alkali-silica and alkali-carbonate reactivity, although alkali-silica reactivity is predominant. Microstructural study suggested that the mechanism in which lithium controls ASR expansion is mainly due to the favorable formation of lithium-containing less-expansive product around aggregate particles and the protection of the reactive aggregate from further attack by alkalis by the lithium-containing product layer

  14. Influence of microstructure on laser damage threshold of IBS coatings

    International Nuclear Information System (INIS)

    Stolz, C.J.; Genin, F.Y.; Kozlowski, M.R.; Long, D.; Lalazari, R.; Wu, Z.L.; Kuo, P.K.

    1996-01-01

    Ion-beam sputtering (IBS) coatings were developed for the laser gyro industry to meet significantly different requirements than those of fusion lasers. Laser gyro mirrors are small ( 26 J/cm 2 at 1,064 nm with 3-ns pulses). As part of the National Ignition Facility (NIF) coating development effort, IBS coatings are being studied to explore the possible benefits of this technology to NIF optics. As an initial step to achieving the NIF size and damage threshold requirements, the coating process is being scaled to uniformly coat a 20 x 40 cm 2 area with reduced spectral, reflected wavefront, and laser damage threshold requirements. Here, multilayer coatings deposited by ion-beam sputtering with amorphous layers were found to have lower damage thresholds at 1,064 nm than similar coatings with crystalline layers. Interestingly, at higher fluences the damage was less severe for the amorphous coatings. The magnitude of the difference in damage thresholds between the two different microstructures was strongly influenced by the size of the tested area. To better understand the microstructure effects, single layers of HfO 2 with different microstructures were studied using transmission electron microscopy, ellipsometry, and a photothermal deflection technique. Since the laser damage initiated at defects, the influence of thermal diffusivity on thermal gradients in nodular defects is also presented

  15. Subgenual Cingulum Microstructure Supports Control of Emotional Conflict

    Science.gov (United States)

    Keedwell, Paul A.; Doidge, Amie N.; Meyer, Marcel; Lawrence, Natalia; Lawrence, Andrew D.; Jones, Derek K.

    2016-01-01

    Major depressive disorder (MDD) is associated with specific difficulties in attentional disengagement from negatively valenced material. Diffusion MRI studies have demonstrated altered white matter microstructure in the subgenual cingulum bundle (CB) in individuals with MDD, though the functional significance of these alterations has not been examined formally. This study explored whether individual differences in selective attention to negatively valenced stimuli are related to interindividual differences in subgenual CB microstructure. Forty-six individuals (21 with remitted MDD, 25 never depressed) completed an emotional Stroop task, using happy and angry distractor faces overlaid by pleasant or unpleasant target words and a control gender-based Stroop task. CBs were reconstructed in 38 individuals using diffusion-weighted imaging and tractography, and mean fractional anisotropy (FA) computed for the subgenual, retrosplenial, and parahippocampal subdivisions. No significant correlations were found between FA and performance in the control gender-based Stroop task in any CB region. However, the degree of interference produced by angry face distractors on time to identify pleasant words (emotional conflict) correlated selectively with FA in the subgenual CB (r = −0.53; P = 0.01). Higher FA was associated with reduced interference, irrespective of a diagnosis of MDD, suggesting that subgenual CB microstructure is functionally relevant for regulating attentional bias toward negative interpersonal stimuli. PMID:27048427

  16. Collagenous microstructure of the glenoid labrum and biceps anchor.

    Science.gov (United States)

    Hill, A M; Hoerning, E J; Brook, K; Smith, C D; Moss, J; Ryder, T; Wallace, A L; Bull, A M J

    2008-06-01

    The glenoid labrum is a significant passive stabilizer of the shoulder joint. However, its microstructural form remains largely unappreciated, particularly in the context of its variety of functions. The focus of labral microscopy has often been histology and, as such, there is very little appreciation of collagen composition and arrangement of the labrum, and hence the micromechanics of the structure. On transmission electron microscopy, significant differences in diameter, area and perimeter were noted in the two gross histological groups of collagen fibril visualized; this suggests a heterogeneous collagenous composition with potentially distinct mechanical function. Scanning electron microscopy demonstrated three distinct zones of interest: a superficial mesh, a dense circumferential braided core potentially able to accommodate hoop stresses, and a loosely packed peri-core zone. Confocal microscopy revealed an articular surface fine fibrillar mesh potentially able to reduce surface friction, bundles of circumferential encapsulated fibres in the bulk of the tissue, and bone anchoring fibres at the osseous interface. Varying microstructure throughout the depth of the labrum suggests a role in accommodating different types of loading. An understanding of the labral microstructure can lead to development of hypotheses based upon an appreciation of this component of material property. This may aid an educated approach to surgical timing and repair.

  17. Subgenual Cingulum Microstructure Supports Control of Emotional Conflict.

    Science.gov (United States)

    Keedwell, Paul A; Doidge, Amie N; Meyer, Marcel; Lawrence, Natalia; Lawrence, Andrew D; Jones, Derek K

    2016-06-01

    Major depressive disorder (MDD) is associated with specific difficulties in attentional disengagement from negatively valenced material. Diffusion MRI studies have demonstrated altered white matter microstructure in the subgenual cingulum bundle (CB) in individuals with MDD, though the functional significance of these alterations has not been examined formally. This study explored whether individual differences in selective attention to negatively valenced stimuli are related to interindividual differences in subgenual CB microstructure. Forty-six individuals (21 with remitted MDD, 25 never depressed) completed an emotional Stroop task, using happy and angry distractor faces overlaid by pleasant or unpleasant target words and a control gender-based Stroop task. CBs were reconstructed in 38 individuals using diffusion-weighted imaging and tractography, and mean fractional anisotropy (FA) computed for the subgenual, retrosplenial, and parahippocampal subdivisions. No significant correlations were found between FA and performance in the control gender-based Stroop task in any CB region. However, the degree of interference produced by angry face distractors on time to identify pleasant words (emotional conflict) correlated selectively with FA in the subgenual CB (r = -0.53; P = 0.01). Higher FA was associated with reduced interference, irrespective of a diagnosis of MDD, suggesting that subgenual CB microstructure is functionally relevant for regulating attentional bias toward negative interpersonal stimuli. © The Author 2016. Published by Oxford University Press.

  18. Hot deformation behavior and microstructure evolution of TA15 titanium alloy with nonuniform microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Pengfei; Zhan, Mei, E-mail: zhanmei@nwpu.edu.cn; Fan, Xiaoguang; Lei, Zhenni; Cai, Yang

    2017-03-24

    The flow behavior and microstructure evolution of a near α titanium alloy with nonuniform microstructure during hot deformation were studied by isothermal compression test and electron backscatter diffraction technique. It is found that the nonuniform microstructure prior to deformation consists of equiaxed α, lamellar α in the colony form and β phase, and the α colony keeps the Burgers orientation relationship with β phase. The flow stress of nonuniform microstructure exhibits significant flow softening after reaching the peak stress at a low strain, which is similar to the lamellar microstructure. Nevertheless, the existence of equiaxed α in nonuniform microstructure makes its flow stress and softening rate be lower than the lamellar microstructure. During deformation, the lamellar α undertakes most of the deformation and turns to be rotated, bended and globularized. Moreover, these phenomena exhibit significant heterogeneity due to the orientation dependence of the deformation of lamellar α. The continuous dynamic recrystallization and bending of lamellar α lead to the “fragmentation” during globularization of lamellar α. The bending of lamellar α is speculated as a form of plastic buckling, because the bending of lamellar α almost proceed in the manner of “rigid rotation” and presents opposite bending directions for the adjacent colonies.

  19. Clinical significance of determination of changes of serum SF, folic acid and vitamin B12 levels in pregnant women of different gestational stages

    International Nuclear Information System (INIS)

    Jiang Hua

    2007-01-01

    Objective: To explore the changes of serum SF, FA and Vitamin Bn levels in pregnant women of different gestational stages. Methods: Levels of serum SF, fore acid and Vitamin B 12 were detected with RIA in 132 pregnant women of different gestational stages and 35 controls (non-pregant women). Results: Serum SF, folic acid and VitB 12 levels were significantly lower in pregnant women of 2nd and 3rd trimester than those in controls (P l2 levels were low in late pregnancy predisposing to development anemia. (authors)

  20. Three-dimensional assessment of crestal bone levels at titanium implants with different abutment microstructures and insertion depths using micro-computed tomography.

    Science.gov (United States)

    Becker, Kathrin; Klitzsch, Inka; Stauber, Martin; Schwarz, Frank

    2017-06-01

    To (i) assess the impact of insertion depth and abutment microstructure on the three-dimensional crestal bone-level changes at endosseous titanium implant using μCT and computerized image processing and (ii) to correlate the findings with previously reported histology. Titanium implants (conical abutment connection) were inserted in each hemimandible of n = 6 foxhounds with the implant shoulder (IS) located either in epicrestal (0 mm), supracrestal (+1 mm) or subcrestal (-1 mm) positions and randomly (split-mouth design) connected with machined or partially micro-grooved healing abutments. At 20 weeks, the tissue biopsies were processed for μCT and histological (HI) analyses. The volumetric dehiscence profile around the implants was computed as distance between the implant shoulder (IS) and the most coronal bone-to-implant contact (CBI) using MATLAB. The respective buccal and oral values were averaged, and agreement with the respective IS-CBI scores from HI was assessed using Bland-Altman plots. A median net bone gain was observed for supracrestal insertion depths at both abutment types, but lower bounds of the 75% quartile experienced net bone losses. Epicrestal and subcrestal insertion depths were linked to slight bone losses, and the buccal and oral dehiscences were smaller compared to supracrestal positioning. Bland-Altman plots yielded a moderate agreement of IS-CBI values measured with μCT and HI. The novel image processing method allowed reliable evaluations and pointed to a direct impact of insertion depths on crestal bone-level changes. Additionally, it demonstrated that HI morphometry crucially depends on the chosen cutting position. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Continuous media with microstructure

    CERN Document Server

    2010-01-01

    This book discusses the extension of classical continuum models. To the first class addressed belong various thermodynamic models of multicomponent systems, and to the second class belong primarily microstructures created by phase transformations.

  2. Optics of dielectric microstructures

    DEFF Research Database (Denmark)

    Søndergaard, Thomas

    2002-01-01

    From the work carried out within the ph.d. project two topics have been selected for this thesis, namely emission of radiation by sources in dielectric microstructures, and planar photonic crystal waveguides. The work done within the first topic, emission of radiation by sources in dielectric...... microstructures, will be presented in the part I of this thesis consisting of the chapters 2-5. An introductions is given in chapter 2. In part I three methods are presented for calculating spontaneous and classical emission from sources in dielectric microstructures. The first method presented in chapter 3...... is based on the Fermi Golden Rule, and spontaneous emission from emitters in a passive dielectric microstructure is calculated by summing over the emission into each electromagnetic mode of the radiation field. This method is applied to investigate spontaneous emission in a two-dimensional photonic crystal...

  3. Prostate cancer risk: the significance of differences in age related changes in serum conjugated and unconjugated steroid hormone concentrations between Arab and Caucasian men.

    Science.gov (United States)

    Kehinde, E O; Akanji, A O; Memon, A; Bashir, A A; Daar, A S; Al-Awadi, K A; Fatinikun, T

    2006-01-01

    Factors responsible for the low incidence of clinical prostate cancer (3-8/100,000 men/year) in the Arab population remain unclear, but may be related to changes in steroid hormone metabolism. We compared the levels of serum conjugated and unconjugated steroids between Arab and Caucasian populations, to determine if these can provide a rational explanation for differences in incidence of prostate cancer between the two populations. Venous blood samples were obtained from 329 unselected apparently healthy indigenous Arab men (Kuwaitis and Omanis) aged 15-80 years. Samples were also obtained from similar Arab men with newly diagnosed prostate cancer or benign prostatic hyperplasia (BPH). The samples were taken between 8:00 am and 12:00 noon. Serum levels of total testosterone, (TT), sex hormone binding globulin (SHBG), free androgen index (FAI); adrenal C19-steroids, dehydroepiandrosterone sulphate (DHEAS) and androstenedione (ADT) were determined using Immulite kits (Diagnostic Systems Laboratories Inc, Webster Texas, USA). The results obtained in Arab men were compared with those reported for similarly aged Chinese, German and White USA men. In all four ethnic groups, median TT and FAI declined with age, while SHBG increased with age. However, the mean TT and SHBG was significantly lower (p Arab men (p Arabs (p Arabs. There was no significant difference in mean serum levels of DHEAS between German and USA men. Similarly, there was no significant difference in the level of the hormones between Arab and Chinese men. Arab men with newly diagnosed prostate cancer had high serum TT, SHBG and DHEAS compared to those without the disease. The mean TT and SHBG was significantly lower in Arab men compared to Caucasian men especially in early adulthood. Caucasians have significantly higher serum levels of the precursor androgens DHEAS and ADT especially in early adulthood compared to Arab men. These observations of low circulating androgens and their adrenal precursors in

  4. Superlattice Microstructured Optical Fiber

    Science.gov (United States)

    Tse, Ming-Leung Vincent; Liu, Zhengyong; Cho, Lok-Hin; Lu, Chao; Wai, Ping-Kong Alex; Tam, Hwa-Yaw

    2014-01-01

    A generic three-stage stack-and-draw method is demonstrated for the fabrication of complex-microstructured optical fibers. We report the fabrication and characterization of a silica superlattice microstructured fiber with more than 800 rhomboidally arranged air-holes. A polarization-maintaining fiber with a birefringence of 8.5 × 10−4 is demonstrated. The birefringent property of the fiber is found to be highly insensitive to external environmental effects, such as pressure. PMID:28788693

  5. Clinical significance of inter-arm pressure difference and ankle-brachial pressure index in patients with suspected coronary artery disease

    International Nuclear Information System (INIS)

    Igarashi, Yuko; Chikamori, Taishiro; Tomiyama, Hirofumi; Usui, Yasuhiro; Hida, Satoshi; Tanaka, Hirokazu; Nagao, Tadashi; Yamashina, Akira

    2007-01-01

    Although measuring blood pressure at the bilateral brachia is common in medical practice, its clinical significance in patients with suspected coronary artery disease (CAD) has not been fully clarified. The method of this study was to define the significance of inter-arm systolic blood pressure difference in patients with suspected CAD, and to assess the relationship between inter-arm pressure difference and CAD, simultaneous brachial and ankle blood pressure measurements and stress myocardial single-photon emission computed tomography (SPECT) were performed in 386 consecutive patients with suspected CAD, excluding those with previous myocardial infarction or coronary revascularization. Subclavian artery stenosis, defined as ≥15 mmHg inter-arm systolic blood pressure difference, was found in 27 patients (7%). Age (65±12 vs 65±11 years), male sex (21/27 vs 244/359), prevalence of hypertension (63% vs 56%), hypercholesterolemia (63% vs 62%), diabetes mellitus (33% vs 38%), cigarette smoking (44% vs 41%) and family history of CAD (15% vs 12%) were similar between patients with subclavian artery stenosis and those without. The incidence of decreased ankle-brachial pressure index (ABI) was higher (37% vs 12%, p=0.001), and percentage ischemic myocardium as assessed by SPECT was greater (9.0±8.5% vs 5.6±6.6%, p=0.05) in patients with subclavian artery stenosis than in those without. Furthermore, significant correlations were observed between inter-arm pressure difference and percentage ischemic myocardium (r=0.13; p=0.01), and ABI (r=-0.26, p<0.0001). Among 386 patients, 283 underwent coronary angiography, and 63% of those who had inter-arm blood pressure difference had CAD. Furthermore, 83% of those CAD patients had multi-vessel CAD, which is regarded as a high-risk subset for subsequent cardiac events. Inter-arm pressure difference is often found in patients with suspected CAD, and is associated with significant CAD and peripheral artery disease. Thus, inter

  6. Alkali Halide Microstructured Optical Fiber for X-Ray Detection

    Science.gov (United States)

    DeHaven, S. L.; Wincheski, R. A.; Albin, S.

    2014-01-01

    Microstructured optical fibers containing alkali halide scintillation materials of CsI(Na), CsI(Tl), and NaI(Tl) are presented. The scintillation materials are grown inside the microstructured fibers using a modified Bridgman-Stockbarger technique. The x-ray photon counts of these fibers, with and without an aluminum film coating are compared to the output of a collimated CdTe solid state detector over an energy range from 10 to 40 keV. The photon count results show significant variations in the fiber output based on the materials. The alkali halide fiber output can exceed that of the CdTe detector, dependent upon photon counter efficiency and fiber configuration. The results and associated materials difference are discussed.

  7. Dependence of triboelectric charging behavior on material microstructure

    Science.gov (United States)

    Wang, Andrew E.; Gil, Phwey S.; Holonga, Moses; Yavuz, Zelal; Baytekin, H. Tarik; Sankaran, R. Mohan; Lacks, Daniel J.

    2017-08-01

    We demonstrate that differences in the microstructure of chemically identical materials can lead to distinct triboelectric charging behavior. Contact charging experiments are carried out between strained and unstrained polytetrafluoroethylene samples. Whereas charge transfer is random between samples of identical strain, when one of the samples is strained, systematic charge transfer occurs. No significant changes in the molecular-level structure of the polymer are observed by XRD and micro-Raman spectroscopy after deformation. However, the strained surfaces are found to exhibit void and craze formation spanning the nano- to micrometer length scales by molecular dynamics simulations, SEM, UV-vis spectroscopy, and naked-eye observations. This suggests that material microstructure (voids and crazes) can govern the triboelectric charging behavior of materials.

  8. Imaging brain tumour microstructure.

    Science.gov (United States)

    Nilsson, Markus; Englund, Elisabet; Szczepankiewicz, Filip; van Westen, Danielle; Sundgren, Pia C

    2018-05-08

    Imaging is an indispensable tool for brain tumour diagnosis, surgical planning, and follow-up. Definite diagnosis, however, often demands histopathological analysis of microscopic features of tissue samples, which have to be obtained by invasive means. A non-invasive alternative may be to probe corresponding microscopic tissue characteristics by MRI, or so called 'microstructure imaging'. The promise of microstructure imaging is one of 'virtual biopsy' with the goal to offset the need for invasive procedures in favour of imaging that can guide pre-surgical planning and can be repeated longitudinally to monitor and predict treatment response. The exploration of such methods is motivated by the striking link between parameters from MRI and tumour histology, for example the correlation between the apparent diffusion coefficient and cellularity. Recent microstructure imaging techniques probe even more subtle and specific features, providing parameters associated to cell shape, size, permeability, and volume distributions. However, the range of scenarios in which these techniques provide reliable imaging biomarkers that can be used to test medical hypotheses or support clinical decisions is yet unknown. Accurate microstructure imaging may moreover require acquisitions that go beyond conventional data acquisition strategies. This review covers a wide range of candidate microstructure imaging methods based on diffusion MRI and relaxometry, and explores advantages, challenges, and potential pitfalls in brain tumour microstructure imaging. Copyright © 2018. Published by Elsevier Inc.

  9. Stochastic Effects in Microstructure

    Directory of Open Access Journals (Sweden)

    Glicksman M.E.

    2002-01-01

    Full Text Available We are currently studying microstructural responses to diffusion-limited coarsening in two-phase materials. A mathematical solution to late-stage multiparticle diffusion in finite systems is formulated with account taken of particle-particle interactions and their microstructural correlations, or "locales". The transition from finite system behavior to that for an infinite microstructure is established analytically. Large-scale simulations of late-stage phase coarsening dynamics show increased fluctuations with increasing volume fraction, Vv, of the mean flux entering or leaving particles of a given size class. Fluctuations about the mean flux were found to depend on the scaled particle size, R/, where R is the radius of a particle and is the radius of the dispersoid averaged over the population within the microstructure. Specifically, small (shrinking particles tend to display weak fluctuations about their mean flux, whereas particles of average, or above average size, exhibit strong fluctuations. Remarkably, even in cases of microstructures with a relatively small volume fraction (Vv ~ 10-4, the particle size distribution is broader than that for the well-known Lifshitz-Slyozov limit predicted at zero volume fraction. The simulation results reported here provide some additional surprising insights into the effect of diffusion interactions and stochastic effects during evolution of a microstructure, as it approaches its thermodynamic end-state.

  10. Biological significance of dead biomass retention trait in Mediterranean Basin species: an analysis between different successional niches and regeneration strategies as functional groups.

    Science.gov (United States)

    Baeza, M J; Santana, V M

    2015-11-01

    Standing dead biomass retention is considered one of the most relevant fuel structural traits to affect plant flammability. However, very little is known about the biological significance of this trait and its distribution between different functional groups. Our aim was to analyse how the proportion of dead biomass produced in Mediterranean species is related to the successional niche of species (early-, mid- and late-successional stages) and the regeneration strategy of species (seeders and resprouters). We evaluated biomass distribution by size classes and standing dead biomass retention in nine dominant species from the Mediterranean Basin in different development stages (5, 9, 14 and 26 years since the last fire). The results revealed significant differences in the standing dead biomass retention of species that presented a distinct successional niche or regeneration strategy. These differences were restricted to the oldest ages studied (>9 years). Tree and small tree resprouters, typical in late-successional stages, presented slight variations with age and a less marked trend to retain dead biomass, while seeder shrubs and dwarf shrubs, characteristic of early-successional stages, showed high dead biomass loads. Our results suggest that the species that tend to retain more dead branches are colonising species that may promote fire in early-successional stages. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  11. Local microstructures, Hardness and mechanical properties of a stainless steel pipe-welded joint

    International Nuclear Information System (INIS)

    Zhao Yongxiang; Gao Qing; Cai Lixun

    2000-01-01

    An experimental investigation is carefully performed into the local microstructures, hardness values and monotonic mechanical properties of the three zones (the base metal, heat affecting zone and weld metal) of 1Cr18Ni9Ti stainless steel pipe-welded joint. The local microstructures are observed by a metallurgical test and a surface replica technology, the local hardness values are measures by a random Vickers hardness test, and the local mechanical properties are characterized by the Ramberg-Osgood and modified Ramberg-Osgood stress-stain relations. The investigation reveals that there are significant differences of the three zones in the local microstructures, hardness values and monotonic mechanical properties, especially of the three zones in the local microstructure, hardness values and monotonic mechanical properties, especially of the weld metal. The weld metal exhibits the largest heterogeneity of local microstructures and monotonic mechanical properties, and the largest scatter of local hardness values. It is necessary to consider these difference and introduce the reliability method to model the scatter in the pipe analysis. In addition, it is verified that a columnar grain structure, which is made up of matrix-rich δ ferrite bands, can characterize the weld metal and the distance between the neighboring rich δ ferrite bands is an appropriate measurement of the columnar grain structure. This measurement is in accordance with the transition point between the microstructural short crack and physical small crack stages, which are generally used for characterizing the short fatigue crack behavior of materials. This indicates that the microstructure controls the fatigue damage character of the present material

  12. Influence of microstructure on low cycle fatigue in some single phase and biphasic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Stolarz, J. [Ecole Nationale Superieure des Mines, Centre SMS, URA CNRS 1884, Saint-Etienne (France)

    2004-07-01

    This overview deals with the effects of microstructural parameters in different single phase and biphasic stainless steels on short crack behaviour and on fatigue life in the low cycle regime. The effect of the grain size is investigated in a single phase austenitic stainless steel. Under plastic strain control, the fatigue life increases when the grain size decreases. The results are discussed by analysing the distributions of crack depths as a function of the grain size. The second type of material is a metastable austenitic steel which partially transforms into martensite during LCF at temperatures between -50 C and +120 C. The grain size of the initially single phase austenitic microstructure has a combined influence on the volume fraction of martensite produced during fatigue and on the fatigue life. In this case, the grain size effect is still considerable but totally indirect because all fatigue cracks grow exclusively in the martensite. The cyclic behaviour analysis in biphasic alloys in which two phases undergo plastic deformation during LCF is considerably more complex because the conventional concept of microstructural barriers cannot be applied. The possible damage patterns in a pair of grains with different mechanical properties are discussed on the example of a solution treated and aged superduplex austenitic-ferritic stainless steel (SDSS). The hardening of one phase (ferrite) through ageing at 475 C changes the cyclic behaviour of the initial ''quasi single phase'' microstructure. Consequently, the fatigue life under plastic strain control decreases compared with the solution treated SDSS. The discussion is focussed on LCF damage mechanisms at the microstructure size scale with a particular accent put on the propagation of short cracks in the bulk. All the microstructures exhibit some common features with respect to the behaviour of short cracks. In particular a strong effect of microstructural barriers in the bulk and the

  13. Microstructures and properties of aluminum die casting alloys

    Energy Technology Data Exchange (ETDEWEB)

    M. M. Makhlouf; D. Apelian; L. Wang

    1998-10-01

    This document provides descriptions of the microstructure of different aluminum die casting alloys and to relate the various microstructures to the alloy chemistry. It relates the microstructures of the alloys to their main engineering properties such as ultimate tensile strength, yield strength, elongation, fatigue life, impact resistance, wear resistance, hardness, thermal conductivity and electrical conductivity. Finally, it serves as a reference source for aluminum die casting alloys.

  14. Market microstructure matters when imposing a Tobin tax—Evidence from the lab☆

    Science.gov (United States)

    Kirchler, Michael; Huber, Jürgen; Kleinlercher, Daniel

    2011-01-01

    Trading in FX markets is dominated by two microstructures: exchanges with market makers and OTC-markets without market makers. Using laboratory experiments we test whether the impact of a Tobin tax is different in these two market microstructures. We find that (i) in markets without market makers an unilaterally imposed Tobin tax (i.e. a tax haven exists) increases volatility. (ii) In contrast, in markets with market makers we observe a decrease in volatility in unilaterally taxed markets. (iii) An encompassing Tobin tax has no impact on volatility in either setting. Efficiency does not vary significantly across tax regimes. PMID:22210970

  15. Market microstructure matters when imposing a Tobin tax-Evidence from the lab.

    Science.gov (United States)

    Kirchler, Michael; Huber, Jürgen; Kleinlercher, Daniel

    2011-12-01

    TRADING IN FX MARKETS IS DOMINATED BY TWO MICROSTRUCTURES: exchanges with market makers and OTC-markets without market makers. Using laboratory experiments we test whether the impact of a Tobin tax is different in these two market microstructures. We find that (i) in markets without market makers an unilaterally imposed Tobin tax (i.e. a tax haven exists) increases volatility. (ii) In contrast, in markets with market makers we observe a decrease in volatility in unilaterally taxed markets. (iii) An encompassing Tobin tax has no impact on volatility in either setting. Efficiency does not vary significantly across tax regimes.

  16. Microstructures and constituents of super-high strength aluminum alloy ingots made through LFEC process

    Directory of Open Access Journals (Sweden)

    WANG Shuang

    2007-11-01

    Full Text Available Ingots of a new super-high strength Al-Zn-Mg-Cu-Zr alloy were produced respectively by low frequency electromagnetic casting (LFEC and by conventional direct chill (DC casting process. Microstructure and constituents of the ingots were studied. The results indicated that the LFEC process significantly refines microstructure and constituents of the alloy, and to some extent, decreases the area (or volume fraction of constituents and eutectic structure precipitated at grain boundaries. But, no difference in the type of constituents was observed between LFEC and DC ingots. The results also showed LFEC process can improve the as-cast mechanical properties.

  17. Microstructural Aspects in FSW and TIG Welding of Cast ZE41A Magnesium Alloy

    Science.gov (United States)

    Carlone, Pierpaolo; Astarita, Antonello; Rubino, Felice; Pasquino, Nicola

    2016-04-01

    In this paper, magnesium ZE41A alloy plates were butt joined through friction stir welding (FSW) and Tungsten Inert Gas welding processes. Process-induced microstructures were investigated by optical and SEM observations, EDX microanalysis and microhardness measurements. The effect of a post-welded T5 heat treatment on FSW joints was also assessed. Sound joints were produced by means of both techniques. Different elemental distributions and grain sizes were found, whereas microhardness profiles reflect microstructural changes. Post-welding heat treatment did not induce significant alterations in elemental distribution. The FSW-treated joint showed a more homogeneous hardness profile than the as-welded FSW joint.

  18. DETECTION OF POLARIZED QUASI-PERIODIC MICROSTRUCTURE EMISSION IN MILLISECOND PULSARS

    Energy Technology Data Exchange (ETDEWEB)

    De, Kishalay; Sharma, Prateek [Department of Physics, Indian Institute of Science, Bangalore 560012 (India); Gupta, Yashwant, E-mail: kde@caltech.edu [National Centre for Radio Astrophysics, TIFR, Pune University Campus, Post Bag 3, Pune 411007 (India)

    2016-12-10

    Microstructure emission, involving short timescale, often quasi-periodic, intensity fluctuations in subpulse emission, is well known in normal period pulsars. In this Letter, we present the first detections of quasi-periodic microstructure emission from millisecond pulsars (MSPs), from Giant Metrewave Radio Telescope observations of two MSPs at 325 and 610 MHz. Similar to the characteristics of microstructure observed in normal period pulsars, we find that these features are often highly polarized and exhibit quasi-periodic behavior on top of broader subpulse emission, with periods of the order of a few μ s. By measuring their widths and periodicities from single pulse intensity profiles and their autocorrelation functions, we extend the microstructure timescale–rotation period relationship by more than an order of magnitude down to rotation periods ∼5 ms, and find it to be consistent with the relationship derived earlier for normal pulsars. The similarity of behavior is remarkable, given the significantly different physical properties of MSPs and normal period pulsars, and rules out several previous speculations about the possible different characteristics of microstructure in MSP radio emission. We discuss the possible reasons for the non-detection of these features in previous high time resolution MSP studies along with the physical implications of our results, both in terms of a geometric beam sweeping model and temporal modulation model for micropulse production.

  19. Nondestructive detection of microstructural fatigue damage

    International Nuclear Information System (INIS)

    Willems, H.; Persch, H.

    1990-02-01

    Ultrasonic as well as magnetic investigations have been performed on a pressure vessel steel (A533, B class 1) in order to study the influence of fatigue loading on both elastic and magnetic material properties. Using laboratory specimens under two different loading conditions (tension-tension loading, tension-compression loading), material characteristics like ultrasonic velocity, ultrasonic absorption, coercivity, incremental permeability were measured and evaluated as a function of consumed lifetime. Only in case of macroscopic plastic deformation, significant changes of the measuring quantities were observed. Otherwise the effects are so small that the nondestructive detection of microstructural changes due to fatigue loading seems not to be feasible under practical conditions (for example at pressure vessels) with the techniques used. Besides a zero measurement, additional measurements on a 1:5 model vessel at JRC Ispra could not be carried out, because the planned fatigue tests were not performed by JRC Ispra during the research period

  20. Nondestructive detection of microstructural fatigue damage

    International Nuclear Information System (INIS)

    Willems, H.; Persch, H.; Voss, B.; Falk, L.

    1989-01-01

    Ultrasonic as well as magnetic investigations have been performed on a pressure vessel steel (A533, B class 1) in order to study the influence of fatigue loading on both elastic and magnetic material properties. Using laboratory specimens under two different loading conditions (tension-tension loading, tension-compression loading), material characteristics like ultrasonic velocity, ultrasonic absorption, coercivity, incremental permeability were measured and evaluated as a function of consumed lifetime. Only in case of macroscopic plastic deformation, significant changes of the measuring quantities were observed. Otherwise the effects are so small that the nondestructive detection of microstructural changes due to high-cycle fatigue loading seems not to be feasible under practical conditions (for example at pressure vessels) with the techniques used. (orig.) [de

  1. Microstructure mechanical properties relationship in bainitic structures

    International Nuclear Information System (INIS)

    Altuna, M. A.; Gutierrez, I.

    2005-01-01

    In the present work, the microstructures and their mechanical properties have been studies in different bainitic structures. therefore, different bainitic morphologies have been produced by isothermal treatments carried out at different temperatures. For these steels, 400-450 degree centigree is the optimum range of temperatures in order to obtain bainitic structures. If the Temperature is higher, perlite is also formed and if it is lower, martensite is obtained during quenching. SEM and EBSD/OIM techniques were applied in order to study the microstructure. Tensile tests were carried out for mechanical characterization. (Author) 20 refs

  2. Significant genotype difference in the CYP2E1 PstI polymorphism of indigenous groups in Sabah, Malaysia with Asian and non-Asian populations.

    Science.gov (United States)

    Goh, Lucky Poh Wah; Chong, Eric Tzyy Jiann; Chua, Kek Heng; Chuah, Jitt Aun; Lee, Ping-Chin

    2014-01-01

    CYP2E1 PstI polymorphism G-1259C (rs3813867) genotype distributions vary significantly among different populations and are associated with both diseases, like cancer, and adverse drug effects. To date, there have been limited genotype distributions and allele frequencies of this polymorphism reported in the three major indigenous ethnic groups (KadazanDusun, Bajau, and Rungus) in Sabah, also known as North Borneo. The aim of this study was to investigate the genotype distributions and allele frequencies of the CYP2E1 PstI polymorphism G-1259C in these three major indigenous peoples in Sabah. A total of 640 healthy individuals from the three dominant indigenous groups were recruited for this study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) at G-1259C polymorphic site of CYP2E1 gene was performed using the Pst I restriction enzyme. Fragments were analyzed using agarose gel electrophoresis and confirmed by direct sequencing. Overall, the allele frequencies were 90.3% for c1 allele and 9.7% for c2 allele. The genotype frequencies for c1/c1, c1/c2 and c2/c2 were observed as 80.9%, 18.8%, and 0.3%, respectively. A highly statistical significant difference (ppopulations. However, among these three indigenous groups, there was no statistical significant difference (p>0.001) in their genotype distributions. The three major indigenous ethnic groups in Sabah show unique genotype distributions when compared with other populations. This finding indicates the importance of establishing the genotype distributions of CYP2E1 PstI polymorphism in the indigenous populations.

  3. Arterio-venous concentration difference of [51Cr]EDTA after a single injection in man. Significance of renal function and local blood flow

    DEFF Research Database (Denmark)

    Rehling, M; Hyldstrup, L; Henriksen, Jens Henrik Sahl

    1989-01-01

    , whereas the difference was very sensitive to even small changes in forearm blood flow within the physiological range. For measurement of renal plasma clearance it is recommended to use one long period: from the time of injection until 300 min p.i. or longer. If the clearance period is too short, the use...... introduced in the measurement of renal plasma clearance and total plasma clearance by using venous blood samples instead of arterial. In 13 patients with GFR ranging from 29 to 150 ml min-1, Ca was higher than Cv immediately after the injection. After mean 38 min (range 12-82 min) the two curves crossed...... of venous samples will overestimate the true renal clearance. Plasma clearance determined by venous and arterial blood samples does not differ significantly as long as the concentration is followed from the time of injection and a long period is applied. When simplified plasma clearance techniques are used...

  4. Clinical significance of determination of changes of serum SF, folic acid and vitamin B{sub 12} levels in pregnant women of different gestational stages

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Jiang [Taizhou City Women and Children Health Station, Jiangsu, Taizhou (China)

    2007-10-01

    Objective: To explore the changes of serum SF, FA and Vitamin Bn levels in pregnant women of different gestational stages. Methods: Levels of serum SF, fore acid and Vitamin B{sub 12} were detected with RIA in 132 pregnant women of different gestational stages and 35 controls (non-pregant women). Results: Serum SF, folic acid and VitB{sub 12} levels were significantly lower in pregnant women of 2nd and 3rd trimester than those in controls (P<0.01), but expect in pregnant women of 1st trimester. Conclusion: Serum SF, folio acid and Vitamin B{sub l2} levels were low in late pregnancy predisposing to development anemia. (authors)

  5. Dynamic contrast-enhanced magnetic resonance imaging: a non-invasive method to evaluate significant differences between malignant and normal tissue

    International Nuclear Information System (INIS)

    Rudisch, Ansgar; Kremser, Christian; Judmaier, Werner; Zunterer, Hildegard; DeVries, Alexander F.

    2005-01-01

    Purpose: An ever recurring challenge in diagnostic radiology is the differentiation between non-malignant and malignant tissue. Based on evidence that microcirculation of normal, non-malignant tissue differs from that of malignant tissue, the goal of this study was to assess the reliability of dynamic contrast-enhanced Magnetic Resonance Imaging (dcMRI) for differentiating these two entities. Materials and methods: DcMRI data of rectum carcinoma and gluteus maximus muscles were acquired in 41 patients. Using an fast T1-mapping sequence on a 1.5-T whole body scanner, T1-maps were dynamically retrieved before, during and after constant rate i.v. infusion of a contrast medium (CM). On the basis of the acquired data sets, PI-values were calculated on a pixel-by-pixel basis. The relevance of spatial heterogeneities of microcirculation was investigated by relative frequency histograms of the PI-values. Results: A statistically significant difference between malignant and normal tissue was found for the mean PI-value (P < 0.001; 8.95 ml/min/100 g ± 2.45 versus 3.56 ml/min/100 g ± 1.20). Additionally relative frequency distributions of PI-values with equal class intervals of 2.5 ml/min/100 g revealed significant differences between the histograms of muscles and rectum carcinoma. Conclusion: We could show that microcirculation differences between malignant and normal, non-malignant tissue can be reliably assessed by non-invasive dcMRI. Therefore, dcMRI holds great promise in the aid of cancer assessment, especially in patients where biopsy is contraindicated

  6. Clinical significance of determination of changes of immuno-function parameters in patients with acute severe brain lnjury on different froms of nutritional support

    International Nuclear Information System (INIS)

    Ma Jun; Qian Quanan; Ma Yunbao; Zhang Xiaoyi; Zhu Jin

    2009-01-01

    Objective: To study the relationship between different forms of nutritional support and changes of serum nutritional as well as immuno-function parameters in patients with acute severe brain injury. Methods: Serum levels of total protein, albumin, hemoglobin, transferrin (with biochemistry), immunoglobulins IgA, IgG, IgM (with immuno-turbidimetry) and cytokines IL-2, IL-6, IL-8 (with RIA) were determined in 64 patients with acute severe brain injury both before and after 7 ∼ 10ds' nutritional support. The 64 patients were divided into two groups:1) experimental group, n=30, receiving parentral (70%) plus partial enteral (30%) feedings 2) control group, n=34, receiving total parenteral untritional support exclusively with equal mitrogen and calorie intake in all the 64 patients. Results: The serum levels of total protein, albumin, Hb and transferrin as well as other parameter in both groups before nutritional support were about the same. After the course of nutritional support, the serum levels of total protein and albumin changed little in both groups, but the Hb and transferritin levels in both groups increased significantly (P<0.05) with the levels significantly higher in the experimental group than those in the control group (P also <0.05). The serum immunoglobulins IgA, IgM levels changed verd littel, except that the IgG levels increased significantly in the experimental group after treatment (P<0.05) and were significantly higher than those in control group (P also <0.05). The serum cytokins levels in the control group changed little after the course of nutritional support, but the levels in the experimental group were greatly normalized and decreased significantly after treatment (P also <0.05). Conclusion: Parenteral combined with partial enteral nutritional support could improve the nutritional as well as immuno-function status better than exclusive TPN did in patients with acute severe brain injury. (authors)

  7. Relationships between microstructure and microfissuring in alloy 718

    Science.gov (United States)

    Thompson, R. G.

    1985-01-01

    Microfissures which occur in the weld heat affected zone of alloy 718 can be a limiting factor in the material's weldability. Several studies have attempted to relate microfissuring susceptibility to processing conditions, microstructure, and/or heat-to-heat chemistry differences. The present investigation studies the relationships between microstructure and microfissuring by isolating a particular microstructural feature and measuring microfissuring as a function of that feature. Results to date include the identification of a microstructure-microfissure sequence, microfissuring susceptibility as a function of grain size, and microfissuring susceptibility as a function of solution annealing time.

  8. Fracture mechanics and microstructures

    International Nuclear Information System (INIS)

    Gee, M.G.; Morrell, R.

    1986-01-01

    The influence of microstructure on defects in ceramics, and the consequences of their presence for the application of fracture mechanics theories are reviewed. The complexities of microstructures, especially the multiphase nature, the crystallographic anisotropy and the resultant anisotropic physical properties, and the variation of microstructure and surface finish from point to point in real components, all lead to considerable uncertainties in the actual performance of any particular component. It is concluded that although the concepts of fracture mechanics have been and will continue to be most useful for the qualitative explanation of fracture phenomena, the usefulness as a predictive tool with respect to most existing types of material is limited by the interrelation between material microstructure and mechanical properties. At present, the only method of eliminating components with unsatisfactory mechanical properties is to proof-test them, despite the fact that proof-testing itself is limited in ability to cope with changes to the component in service. The aim of the manufacturer must be to improve quality and consistency within individual components, from component to component, and from batch to batch. The aim of the fracture specialist must be to study longer-term properties to improve the accuracy of behaviour predictions with a stronger data base. Materials development needs to concentrate on obtaining defect-free materials that can be translated into more-reliable products, using our present understanding of the influence of microstructure on strength and toughness

  9. Effect of food microstructure on growth dynamics of Listeria monocytogenes in fish-based model systems.

    Science.gov (United States)

    Verheyen, Davy; Bolívar, Araceli; Pérez-Rodríguez, Fernando; Baka, Maria; Skåra, Torstein; Van Impe, Jan F

    2018-06-01

    Traditionally, predictive growth models for food pathogens are developed based on experiments in broth media, resulting in models which do not incorporate the influence of food microstructure. The use of model systems with various microstructures is a promising concept to get more insight into the influence of food microstructure on microbial dynamics. By means of minimal variation of compositional and physicochemical factors, these model systems can be used to study the isolated effect of certain microstructural aspects on microbial growth, survival and inactivation. In this study, the isolated effect on microbial growth dynamics of Listeria monocytogenes of two food microstructural aspects and one aspect influenced by food microstructure were investigated, i.e., the nature of the food matrix, the presence of fat droplets, and microorganism growth morphology, respectively. To this extent, fish-based model systems with various microstructures were used, i.e., a liquid, a second more viscous liquid system containing xanthan gum, an emulsion, an aqueous gel, and a gelled emulsion. Growth experiments were conducted at 4 and 10 °C, both using homogeneous and surface inoculation (only for the gelled systems). Results regarding the influence of the growth morphology indicated that the lag phase of planktonic cells in the liquid system was similar to the lag phase of submerged colonies in the xanthan system. The lag phase of submerged colonies in each gelled system was considerably longer than the lag phase of surface colonies on these respective systems. The maximum specific growth rate of planktonic cells in the liquid system was significantly lower than for submerged colonies in the xanthan system at 10 °C, while no significant differences were observed at 4 °C. The maximum cell density was higher for submerged colonies than for surface colonies. The nature of the food matrix only exerted an influence on the maximum specific growth rate, which was

  10. DNA Methylation Profiling of Human Prefrontal Cortex Neurons in Heroin Users Shows Significant Difference between Genomic Contexts of Hyper- and Hypomethylation and a Younger Epigenetic Age

    Directory of Open Access Journals (Sweden)

    Alexey Kozlenkov

    2017-05-01

    Full Text Available We employed Illumina 450 K Infinium microarrays to profile DNA methylation (DNAm in neuronal nuclei separated by fluorescence-activated sorting from the postmortem orbitofrontal cortex (OFC of heroin users who died from heroin overdose (N = 37, suicide completers (N = 22 with no evidence of heroin use and from control subjects who did not abuse illicit drugs and died of non-suicide causes (N = 28. We identified 1298 differentially methylated CpG sites (DMSs between heroin users and controls, and 454 DMSs between suicide completers and controls (p < 0.001. DMSs and corresponding genes (DMGs in heroin users showed significant differences in the preferential context of hyper and hypo DM. HyperDMSs were enriched in gene bodies and exons but depleted in promoters, whereas hypoDMSs were enriched in promoters and enhancers. In addition, hyperDMGs showed preference for genes expressed specifically by glutamatergic as opposed to GABAergic neurons and enrichment for axonogenesis- and synaptic-related gene ontology categories, whereas hypoDMGs were enriched for transcription factor activity- and gene expression regulation-related terms. Finally, we found that the DNAm-based “epigenetic age” of neurons from heroin users was younger than that in controls. Suicide-related results were more difficult to interpret. Collectively, these findings suggest that the observed DNAm differences could represent functionally significant marks of heroin-associated plasticity in the OFC.

  11. Significant differences in gene expression and key genetic components associated with high growth vigor in populus section tacamahaca as revealed by comparative transcriptome analysis

    International Nuclear Information System (INIS)

    Cheng, S.; Chen, M.; Li, Y.; Wang, J.; Sun, X.; Wang, J.

    2017-01-01

    To identify genetic components involved in high growth vigor in F1 Populus section Tacamahaca hybrid plants, high and low vigor plants showing significant differences in apical dominance during a rapid growth period were selected. Apical bud transcriptomes of high and low-growth-vigor hybrids and their parents were analyzed using high-throughput RNA sequencing on an Illumina HiSeq 2000 platform. A total of 5,542 genes were differently expressed between high growth vigor hybrid and its parents, the genes were significantly enriched in pathways related to processes such as photosynthesis, pyrimidine ribonucleotide biosynthetic processes and nucleoside metabolic processes. There were 1410 differentially expressed genes between high and low growth vigor hybrid, the genes were mainly involved in photosynthesis, chlorophyll biosynthetic process, carbon fixation in photosynthetic organisms, porphyrin and chlorophyll metabolism and nitrogen metabolism. Moreover, a k-core of a gene co-expression network analysis was performed to identify the potential functions of genes related to high growth vigor. The functions of 8 selected candidate genes were associated mainly with circadian rhythm, water transport, cellulose catabolic processes, sucrose biosynthesis, pyrimidine ribonucleotide biosynthesis, purine nucleotide biosynthesis, meristem maintenance, and carbohydrate metabolism. Our results may contribute to a better understanding of the molecular basis of high growth vigor in hybrids and its regulation. (author)

  12. Evolution of microstructure and texture in copper during repetitive extrusion-upsetting and subsequent annealing

    DEFF Research Database (Denmark)

    Chen, Q.; Shu, D. Y.; Lin, J.

    2017-01-01

    The evolution of the microstructure and texture in copper has been studied during repetitive extrusion-upsetting (REU) to a total von Mises strain of 4.7 and during subsequent annealing at different temperatures. It is found that the texture is significantly altered by each deformation pass...... strain of 4.7 is measured to be ∼0.3μm. This refined microstructure is unstable at room temperature as is evident from the presence of a small number of recrystallized grains in the deformed matrix. Pronounced recrystallization took place during annealing at 200 °C for 1 h with recrystallized grains...... developing predominantly in high misorientation regions. At 350 ºC the microstructure is fully recrystallized with an average grain size of only 2.3 μm and a very weak crystallographic texture. This REU-processed and subsequently annealed material is considered to be potentially suitable for using...

  13. Influence of superplasticizer on microstructure of a 40 MPa strength concrete

    International Nuclear Information System (INIS)

    Teixeira, Sandra M.F.; Menezes, Raquel Maria R.O.; Figueiredo, Roberto B.; Aguilar, Maria Teresa P.; Franca, Fabricio Carlos; Bezerra, Augusto Cesar da S.

    2016-01-01

    The self compacting concrete has high fluidity and deformability. Studies analyze its performance through compressive strength, mortar content and / or water cement factor, which does not allow the evaluation of superplasticante influence the microstructure of these concretes. In this work, we evaluated the influence of superplasticizer comparing the phases present in a self-compacting concrete 40 MPa and at a same conventional compressive strength, same water / cement and mortar content. Therefore, scanning techniques were employed by electron microscope low vacuum using backscattered electrons and thermal analysis. The observed results show no significant differences in the microstructure of the two composites, ie the superplasticizer does not alter the microstructure of the self-compacting concrete. However, thermal analysis indicates that the present self-compacting concrete greater calcium hydroxide content which may suggest a lower content of such dry cement concrete. (author)

  14. Microstructural characterization of fly ash particulate reinforced AA6063 aluminium alloy for aerospace applications

    Science.gov (United States)

    Razzaq, A. M.; Majid, D. L. Abang Abdul; Ishak, M. R.; Uday, M. B.

    2017-12-01

    Aluminium-fly ash (FA) particulate reinforced composites (AA6063-FA) have been used in automotive and aerospace industries because of their low density and good mechanical properties. Three different weight fraction of FA: 2%, 4% and 6% are added to AA6063 alloy using compocasting method. The effect of FA particulates on microstructure, density and compression strength of AA6063- FA composites are investigated. Field Emission Scanning Electron Microscope (FESEM) micrographs reveal that the FA particulates are uniformly distributed in AA6063 alloy. The results also show that density, compression strength and microstructure of the AA6063-FA composites are significantly influenced by the FA amount. The increase in the weight fraction of FA will improve the microstructure and enhance the compression strength. The density of AA6063-FA composites decreases as the incorporation of FA increases.

  15. Is the prognostic significance of O6-methylguanine- DNA methyltransferase promoter methylation equally important in glioblastomas of patients from different continents? A systematic review with meta-analysis.

    Science.gov (United States)

    Meng, Wei; Jiang, Yangyang; Ma, Jie

    2017-01-01

    O6-methylguanine-DNA methyltransferase (MGMT) is an independent predictor of therapeutic response and potential prognosis in patients with glioblastoma multiforme (GBM). However, its significance of clinical prognosis in different continents still needs to be explored. To explore the effects of MGMT promoter methylation on both progression-free survival (PFS) and overall survival (OS) among GBM patients from different continents, a systematic review of published studies was conducted. A total of 5103 patients from 53 studies were involved in the systematic review and the total percentage of MGMT promoter methylation was 45.53%. Of these studies, 16 studies performed univariate analyses and 17 performed multivariate analyses of MGMT promoter methylation on PFS. The pooled hazard ratio (HR) estimated for PFS was 0.55 (95% CI 0.50, 0.60) by univariate analysis and 0.43 (95% CI 0.38, 0.48) by multivariate analysis. The effect of MGMT promoter methylation on OS was explored in 30 studies by univariate analysis and in 30 studies by multivariate analysis. The combined HR was 0.48 (95% CI 0.44, 0.52) and 0.42 (95% CI 0.38, 0.45), respectively. In each subgroup divided by areas, the prognostic significance still remained highly significant. The proportion of methylation in each group was in inverse proportion to the corresponding HR in the univariate and multivariate analyses of PFS. However, from the perspective of OS, compared with data from Europe and the US, higher methylation rates in Asia did not bring better returns.

  16. Prognostic Significance of the Systemic Inflammatory and Immune Balance in Alcoholic Liver Disease with a Focus on Gender-Related Differences.

    Directory of Open Access Journals (Sweden)

    Beata Kasztelan-Szczerbińska

    Full Text Available Mechanisms of immune regulation in alcoholic liver disease (ALD are still unclear. The aim of our study was to determine an impact of Th17 / regulatory T (Treg cells balance and its corresponding cytokine profile on the ALD outcome. Possible gender-related differences in the alcohol-induced inflammatory response were also assessed.147 patients with ALD were prospectively recruited, assigned to subgroups based on their gender, severity of liver dysfunction and presence of ALD complications at admission, and followed for 90 days. Peripheral blood frequencies of Th17 and Treg cells together with IL-1beta, IL-6, IL-17A, IL-23, and TGF-beta1 levels were investigated. Flow cytometry was used to identify T cell phenotype and immunoenzymatic ELISAs for the corresponding cytokine concentrations assessment. Multivariable logistic regression was applied in order to select independent predictors of advanced liver dysfunction and the disease complications.IL-17A, IL-1beta, IL-6 levels were significantly increased, while TGF-beta1 decreased in ALD patients. The imbalance with significantly higher Th17 and lower Treg frequencies was observed in non-survivors. IL-6 and TGF-beta1 levels differed in relation to patient gender in ALD group. Concentrations of IL-6 were associated with the severity of liver dysfunction, development of ALD complications, and turned out to be the only independent immune predictor of 90-day survival in the study cohort.We conclude that IL-6 revealed the highest diagnostic and prognostic potential among studied biomarkers and was related to the fatal ALD course. Gender-related differences in immune regulation might influence the susceptibility to alcohol-associated liver injury.

  17. Young Mania Rating Scale: how to interpret the numbers? Determination of a severity threshold and of the minimal clinically significant difference in the EMBLEM cohort.

    Science.gov (United States)

    Lukasiewicz, Michael; Gerard, Stephanie; Besnard, Adeline; Falissard, Bruno; Perrin, Elena; Sapin, Helene; Tohen, Mauricio; Reed, Catherine; Azorin, Jean-Michel

    2013-03-01

    The aim of this analysis was to identify Young Mania Rating Scale (YMRS) meaningful benchmarks for clinicians (severity threshold, minimal clinically significant difference [MCSD]) using the Clinical Global Impressions Bipolar (CGI-BP) mania scale, to provide a clinical perspective to randomized clinical trials (RCTs) results. We used the cohort of patients with acute manic/mixed state of bipolar disorders (N = 3459) included in the European Mania in Bipolar Longitudinal Evaluation of Medication (EMBLEM) study. A receiver-operating characteristic analysis was performed on randomly selected patients to determine the YMRS optimal severity threshold with CGI-BP mania score ≥ "Markedly ill" defining severity. The MCSD (clinically meaningful change in score relative to one point difference in CGI-BP mania for outcome measures) of YMRS, was assessed with a linear regression on baseline data. At baseline, YMRS mean score was 26.4 (±9.9), CGI-BP mania mean score was 4.8 (±1.0) and 61.7% of patients had a score ≥ 5. The optimal YMRS severity threshold of 25 (positive predictive value [PPV] = 83.0%; negative predictive value [NPV] = 66.0%) was determined. In this cohort, a YMRS score of 20 (typical cutoff for RCTs inclusion criteria) corresponds to a PPV of 74.6% and to a NPV of 77.6%, meaning that the majority of patients included would be classified as severely ill. The YMRS minimal clinically significant difference was 6.6 points. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Geographical and genetic factors do not account for significant differences in the clinical spectrum of giant cell arteritis in southern europe.

    Science.gov (United States)

    Gonzalez-Gay, Miguel A; Boiardi, Luigi; Garcia-Porrua, Carlos; Macchioni, Pierluigi; Amor-Dorado, Juan C; Salvarani, Carlo

    2004-03-01

    To investigate whether genetic and geographical differences may influence the clinical spectrum of giant cell arteritis (GCA), we compared the demographic and clinical features of patients with biopsy-proven GCA from Reggio Emilia (Northern Italy) and Lugo (Northwest Spain) during a 15-year period. We performed a retrospective review of the case records of all patients diagnosed with biopsy-proven GCA at Hospital Xeral-Calde (Lugo, Spain) and Hospital Santa Maria Nuova (Reggio Emilia, Italy) between 1 January 1986 and 31 December 2001. Both hospitals are the only referral centers for populations living in central Galicia and central Emilia Romagna, respectively. During the period of study, 194 Lugo residents and 126 Reggio Emilia residents were diagnosed with biopsy proven GCA. Reggio Emilia patients were more likely to be female (74% vs 54%; p = 0.0001). Although Lugo patients complained of headache (86%) more commonly than did those from Reggio Emilia (77%), the difference was only marginally significant (p = 0.05). The proportion of patients with visual manifestations or visual loss was remarkably similar (22% for visual manifestations and 17% for visual loss in Lugo and 29% and 21% for Reggio Emilia residents). The mean erythrocyte sedimentation rate prior to the onset of therapy was also similar. Apart from differences in sex, the clinical spectrum of GCA in these 2 Southern European regions was similar.

  19. Microstructuring of glasses

    CERN Document Server

    Hülsenberg, Dagmar; Bismarck, Alexander

    2008-01-01

    As microstructured glass becomes increasingly important for microsystems technology, the main application fields include micro-fluidic systems, micro-analysis systems, sensors, micro-actuators and implants. And, because glass has quite distinct properties from silicon, PMMA and metals, applications exist where only glass devices meet the requirements. The main advantages of glass derive from its amorphous nature, the precondition for its - theoretically - direction-independent geometric structurability. Microstructuring of Glasses deals with the amorphous state, various glass compositions and their properties, the interactions between glasses and the electromagnetic waves used to modify it. Also treated in detail are methods for influencing the geometrical microstructure of glasses by mechanical, chemical, thermal, optical, and electrical treatment, and the methods and equipment required to produce actual microdevices.

  20. Microstructural development in a rapidly solidified Al-Fe-V-Si alloy

    International Nuclear Information System (INIS)

    Park, W.J.; Baek, E.R.; Lee, Sunghak; Kim, N.J.

    1991-01-01

    TEM is used to investigate microstructural development in a rapidly solidified Al-Fe-V-Si alloy. The as-cast microstructure of a rapidly solidified Al-Fe-V-Si alloy was found to vary depending on casting conditions and also through the thickness of ribbon. For completely Zone A ribbon, intercellular phase consists of a microquasi-crystalline phase, while for the Zone A and Zone B mixed ribbon, it consists of a silicide phase. In either case, formation of globular particles of a cluster microquasi-crystalline phase is observed near the air side of the ribbon. Annealing study shows significant differences in the final microstructure depending on the initial status of the ribbon. Completely Zone A ribbon, whose microstructure is composed of a microquasi-crystalline phase, results in a very coarse microstructure after annealing as compared to the Zone A and Zone B mixed ribbon. This result has important implications for the development of high-performance elevated-temperature Al alloys. 12 refs

  1. Study of the microstructure evolution of ferritic stainless ODS steels during hot working

    International Nuclear Information System (INIS)

    Karch, Abdellatif

    2014-01-01

    The production of ODS steels involves a powder consolidation step usually using the hot extrusion (HE) process. The anisotropic properties of extruded materials, especially in the ODS ferritic grades (≥wt%12Cr), need a better understanding of the metallurgical phenomena which may occur during HE and lead to the observed microstructure. The hot working behavior of these materials is of particular interest. The methodology of this work includes the microstructure analysis after interrupted hot extrusion, hot torsion and hot compression (1000-1200 C) tests of ferritic steels with 14%Cr and different amounts in Ti and Y 2 O 3 . The microstructure evolution during hot extrusion process is associated with continuous dynamic recrystallization (CDRX). It leads to the creation of new grains by the formation of low angle boundaries, and then the increase of their misorientation under plastic deformation. The investigations highlight also the role of precipitation on the kinetics of this mechanism; it remains incomplete in the presence of fine and dense nano-precipitates. After hot deformation in torsion and compression, it is noticed that both precipitates and temperature deformation have a significant impact on the deformation mechanisms and microstructure evolution. Indeed, the CDRX is dominant when temperature and amount of reinforcement are limited. However, when they are increased, limited microstructure evolution is observed. In this case, the results are interpreted through a mechanism of strain accommodation at grain boundaries, with low dislocation activity in the bulk of the grains. (author) [fr

  2. Quantitative interface models for simulating microstructure evolution

    International Nuclear Information System (INIS)

    Zhu, J.Z.; Wang, T.; Zhou, S.H.; Liu, Z.K.; Chen, L.Q.

    2004-01-01

    To quantitatively simulate microstructural evolution in real systems, we investigated three different interface models: a sharp-interface model implemented by the software DICTRA and two diffuse-interface models which use either physical order parameters or artificial order parameters. A particular example is considered, the diffusion-controlled growth of a γ ' precipitate in a supersaturated γ matrix in Ni-Al binary alloys. All three models use the thermodynamic and kinetic parameters from the same databases. The temporal evolution profiles of composition from different models are shown to agree with each other. The focus is on examining the advantages and disadvantages of each model as applied to microstructure evolution in alloys

  3. Meal Microstructure Characterization from Sensor-Based Food Intake Detection

    Directory of Open Access Journals (Sweden)

    Abul Doulah

    2017-07-01

    Full Text Available To avoid the pitfalls of self-reported dietary intake, wearable sensors can be used. Many food ingestion sensors offer the ability to automatically detect food intake using time resolutions that range from 23 ms to 8 min. There is no defined standard time resolution to accurately measure ingestive behavior or a meal microstructure. This paper aims to estimate the time resolution needed to accurately represent the microstructure of meals such as duration of eating episode, the duration of actual ingestion, and number of eating events. Twelve participants wore the automatic ingestion monitor (AIM and kept a standard diet diary to report their food intake in free-living conditions for 24 h. As a reference, participants were also asked to mark food intake with a push button sampled every 0.1 s. The duration of eating episodes, duration of ingestion, and number of eating events were computed from the food diary, AIM, and the push button resampled at different time resolutions (0.1–30s. ANOVA and multiple comparison tests showed that the duration of eating episodes estimated from the diary differed significantly from that estimated by the AIM and the push button (p-value <0.001. There were no significant differences in the number of eating events for push button resolutions of 0.1, 1, and 5 s, but there were significant differences in resolutions of 10–30s (p-value <0.05. The results suggest that the desired time resolution of sensor-based food intake detection should be ≤5 s to accurately detect meal microstructure. Furthermore, the AIM provides more accurate measurement of the eating episode duration than the diet diary.

  4. Significant differences in maternal child-feeding style between ethnic groups in the UK: the role of deprivation and parenting styles.

    Science.gov (United States)

    Korani, M; Rea, D M; King, P F; Brown, A E

    2018-04-03

    Nonresponsive maternal child-feeding interactions, such as restricting, pressurising and emotional feeding, can affect the ability of a child to self-regulate intake and increase the risk of becoming overweight. However, despite findings that South Asian and Black children living in the UK are more likely to be overweight, UK research has not considered how maternal child-feeding style might differ between ethnic groups. The present study aimed to explore variations in maternal child-feeding style between ethnic groups in the UK, taking into account associated factors such as deprivation and parenting style. Six hundred and fifty-nine UK mothers with a child who was aged 5-11 years old completed a questionnaire. Items included ethnicity and demographic data, as well as copies of the Child Feeding Questionnaire, Parental Feeding Styles Questionnaire and Parenting Styles and Dimensions Questionnaire. Significant differences in perceived responsibility (P = 0.002), restriction (P = 0.026), pressure to eat (P = 0.045), instrumental feeding (P = 0.000) and emotional feeding (P = 0.000) were found between the groups. Mothers from South Asian backgrounds reported higher levels of pressure to eat, emotional feeding and indulgent feeding styles, whereas mothers from Chinese backgrounds reported greater perceived responsibility and restriction. Mothers from Black and White British backgrounds were not significantly higher with respect to any behaviour. Maternal child-feeding style was also associated with deprivation and parenting style, although these did not fully explain the data. Understanding cultural factors behind maternal child-feeding style, particularly around pressurising and indulgent feeding behaviours, may play an important part in reducing levels of children who are overweight and obese in the UK. © 2018 The British Dietetic Association Ltd.

  5. Influence of surfactants on the microstructure of dental zirconia ceramics

    International Nuclear Information System (INIS)

    Il'icheva, A. A.; Michalina, N. A.; Podzorova, L. I.; Pen'kova, O. I.; Kutsev, S. V.; Berezina, S.

    2013-01-01

    This work studies the influence of different surfactants included in the synthesis of precursor powders on the microstructure of ceramic material to search for an optimal agents providing an uniform grain microstructure required for accurate medical products with a high degree of surface cleanliness. (authors)

  6. AxTract: Toward microstructure informed tractography.

    Science.gov (United States)

    Girard, Gabriel; Daducci, Alessandro; Petit, Laurent; Thiran, Jean-Philippe; Whittingstall, Kevin; Deriche, Rachid; Wassermann, Demian; Descoteaux, Maxime

    2017-11-01

    Diffusion-weighted (DW) magnetic resonance imaging (MRI) tractography has become the tool of choice to probe the human brain's white matter in vivo. However, tractography algorithms produce a large number of erroneous streamlines (false positives), largely due to complex ambiguous tissue configurations. Moreover, the relationship between the resulting streamlines and the underlying white matter microstructure characteristics remains poorly understood. In this work, we introduce a new approach to simultaneously reconstruct white matter fascicles and characterize the apparent distribution of axon diameters within fascicles. To achieve this, our method, AxTract, takes full advantage of the recent development DW-MRI microstructure acquisition, modeling, and reconstruction techniques. This enables AxTract to separate parallel fascicles with different microstructure characteristics, hence reducing ambiguities in areas of complex tissue configuration. We report a decrease in the incidence of erroneous streamlines compared to the conventional deterministic tractography algorithms on simulated data. We also report an average increase in streamline density over 15 known fascicles of the 34 healthy subjects. Our results suggest that microstructure information improves tractography in crossing areas of the white matter. Moreover, AxTract provides additional microstructure information along the fascicle that can be studied alongside other streamline-based indices. Overall, AxTract provides the means to distinguish and follow white matter fascicles using their microstructure characteristics, bringing new insights into the white matter organization. This is a step forward in microstructure informed tractography, paving the way to a new generation of algorithms able to deal with intricate configurations of white matter fibers and providing quantitative brain connectivity analysis. Hum Brain Mapp 38:5485-5500, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Ovarian follicular dynamics and plasma steroid concentrations are not significantly different in ewes given intravaginal sponges containing either 20 or 40 mg of fluorogestone acetate.

    Science.gov (United States)

    Letelier, C A; Contreras-Solis, I; García-Fernández, R A; Ariznavarreta, C; Tresguerres, J A F; Flores, J M; Gonzalez-Bulnes, A

    2009-03-01

    Although various progestagens are often used to induce and synchronize estrus and ovulation in ruminants, concerns regarding residues are the impetus to develop alternative approaches, including reduced doses of progestagens. Therefore, the objective was to determine whether ovarian function was affected by halving the dose of fluorogestone acetate in intravaginal sponges for synchronizing ovulation in sheep during the physiologic breeding season. Twenty Manchega ewes, 4-6-year-old, were randomly allocated to receive an intravaginal sponge containing either 20mg (P20, n=10) or 40 mg of fluorogestone acetate (P40, n=10). Cloprostenol (125 microg) was given at sponge insertion, and all sponges were removed after 6d. Ovarian follicular dynamics (monitored by daily ultrasonography) and other aspects of ovarian function did not differ significantly between the two groups. Ovulatory follicles (OF) grew at a similar growth rate (r=0.62; Pprogesterone concentrations (3.8+/-0.35 ng/mL for P20 and 3.9+/-0.38 ng/mL for P40) were similar. In conclusion, reducing the dose of fluorogestone acetate from 40 to 20mg did not affect significantly ovarian follicular dynamics or other aspects of ovarian function.

  8. The microstructure and rheology of a model, thixotropic nanoparticle gel under steady shear and large amplitude oscillatory shear (LAOS)

    International Nuclear Information System (INIS)

    Min Kim, Jung; Kate Gurnon, A.; Wagner, Norman J.; Eberle, Aaron P. R.; Porcar, Lionel

    2014-01-01

    The microstructure-rheology relationship for a model, thermoreversible nanoparticle gel is investigated using a new technique of time-resolved neutron scattering under steady and time-resolved large amplitude oscillatory shear (LAOS) flows. A 21 vol. % gel is tested with varying strength of interparticle attraction. Shear-induced structural anisotropy is observed as butterfly scattering patterns and quantified through an alignment factor. Measurements in the plane of flow show significant, local anisotropy develops with alignment along the compressional axis of flow, providing new insights into how gels flow. The microstructure-rheology relationship is analyzed through a new type of structure-Lissajous plot that shows how the anisotropic microstructure is responsible for the observed LAOS response, which is beyond a response expected for a purely viscous gel with constant structure. The LAOS shear viscosities are observed to follow the “Delaware-Rutgers” rule. Rheological and microstructural data are successfully compared across a broad range of conditions by scaling the shear rate by the strength of attraction, providing a method to compare behavior between steady shear and LAOS experiments. However, important differences remain between the microstructures measured at comparatively high frequency in LAOS experiments and comparable steady shear experiments that illustrate the importance of measuring the microstructure to properly interpret the nonlinear, dynamic rheological response

  9. The microstructure and rheology of a model, thixotropic nanoparticle gel under steady shear and large amplitude oscillatory shear (LAOS)

    Energy Technology Data Exchange (ETDEWEB)

    Min Kim, Jung; Kate Gurnon, A.; Wagner, Norman J., E-mail: wagnernj@udel.edu [Department of Chemical and Biomolecular Engineering and Center for Neutron Science, University of Delaware, Newark, Delaware 19716 (United States); Eberle, Aaron P. R. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Porcar, Lionel [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 and Institut Laue-Langevin, BP 156, F-38042 Grenoble Cedex 9 (France)

    2014-09-01

    The microstructure-rheology relationship for a model, thermoreversible nanoparticle gel is investigated using a new technique of time-resolved neutron scattering under steady and time-resolved large amplitude oscillatory shear (LAOS) flows. A 21 vol. % gel is tested with varying strength of interparticle attraction. Shear-induced structural anisotropy is observed as butterfly scattering patterns and quantified through an alignment factor. Measurements in the plane of flow show significant, local anisotropy develops with alignment along the compressional axis of flow, providing new insights into how gels flow. The microstructure-rheology relationship is analyzed through a new type of structure-Lissajous plot that shows how the anisotropic microstructure is responsible for the observed LAOS response, which is beyond a response expected for a purely viscous gel with constant structure. The LAOS shear viscosities are observed to follow the “Delaware-Rutgers” rule. Rheological and microstructural data are successfully compared across a broad range of conditions by scaling the shear rate by the strength of attraction, providing a method to compare behavior between steady shear and LAOS experiments. However, important differences remain between the microstructures measured at comparatively high frequency in LAOS experiments and comparable steady shear experiments that illustrate the importance of measuring the microstructure to properly interpret the nonlinear, dynamic rheological response.

  10. Ultrasonic characterization of microstructure in powder metal alloy

    Science.gov (United States)

    Tittmann, B. R.; Ahlberg, L. A.; Fertig, K.

    1986-01-01

    The ultrasonic wave propagation characteristics were measured for IN-100, a powder metallurgy alloy used for aircraft engine components. This material was as a model system for testing the feasibility of characterizing the microstructure of a variety of inhomogeneous media including powder metals, ceramics, castings and components. The data were obtained for a frequency range from about 2 to 20 MHz and were statistically averaged over numerous volume elements of the samples. Micrographical examination provided size and number distributions for grain and pore structure. The results showed that the predominant source for the ultrasonic attenuation and backscatter was a dense (approx. 100/cubic mm) distribution of small micropores (approx. 10 micron radius). Two samples with different micropore densities were studied in detail to test the feasibility of calculating from observed microstructural parameters the frequency dependence of the microstructural backscatter in the regime for which the wavelength is much larger than the size of the individual scattering centers. Excellent agreement was found between predicted and observed values so as to demonstrate the feasibility of solving the forward problem. The results suggest a way towards the nondestructive detection and characterization of anomalous distributions of micropores when conventional ultrasonic imaging is difficult. The findings are potentially significant toward the application of the early detection of porosity during the materials fabrication process and after manufacturing of potential sites for stress induced void coalescence leading to crack initiation and subsequent failure.

  11. Race and Sex Differences in the Incidence and Prognostic Significance of Silent Myocardial Infarction in the Atherosclerosis Risk in Communities (ARIC) Study.

    Science.gov (United States)

    Zhang, Zhu-Ming; Rautaharju, Pentti M; Prineas, Ronald J; Rodriguez, Carlos J; Loehr, Laura; Rosamond, Wayne D; Kitzman, Dalane; Couper, David; Soliman, Elsayed Z

    2016-05-31

    Race and sex differences in silent myocardial infarction (SMI) are not well established. The analysis included 9498 participants from the Atherosclerosis Risk in Communities (ARIC) study who were free of cardiovascular disease at baseline (visit 1, 1987-1989). Incident SMI was defined as ECG evidence of MI without clinically documented MI (CMI) after the baseline until ARIC visit 4 (1996-1998). Coronary heart disease and all-cause deaths were ascertained starting from ARIC visit 4 until 2010. During a median follow-up of 8.9 years, 317 participants (3.3%) developed SMI and 386 (4.1%) developed CMI. The incidence rates of both SMI and CMI were higher in men (5.08 and 7.96 per 1000-person years, respectively) than in women (2.93 and 2.25 per 1000-person years, respectively; Prace were detected. SMI represents >45% of incident MIs and is associated with poor prognosis. Race and sex differences in the incidence and prognostic significance of SMI exist that may warrant considering SMI in personalized assessments of coronary heart disease risk. © 2016 American Heart Association, Inc.

  12. Compositional Similarities and Differences between Transparent Exopolymer Particles (TEP) from two Marine Bacteria and two Marine Algae: Significance to Surface Biofouling

    KAUST Repository

    Li, Sheng

    2015-06-12

    Transparent-exopolymer-particles (TEP) have been recently identified as a significant contributor to surface biofouling, such as on reverse osmosis (RO) membranes. TEP research has mainly focused on algal TEP/TEP precursors while limited investigations have been conducted on those released by bacteria. In this study, TEP/TEP precursors derived from both algae and bacteria were isolated and then characterized to investigate their similarities and/or differences using various advanced analytical techniques, thus providing a better understanding of their potential effect on biofouling. Bacterial TEP/TEP precursors were isolated from two species of marine bacteria (Pseudidiomarina homiensis and Pseudoalteromonas atlantica) while algal TEP/TEP precursors were isolated from two marine algae species (Alexandrium tamarense and Chaetoceros affinis). Results indicated that both isolated bacterial and algal TEP/TEP precursors were associated with protein-like materials, and most TEP precursors were high-molecular-weight biopolymers. Furthermore all investigated algal and bacterial TEP/TEP precursors showed a lectin-like property, which can enable them to act as a chemical conditioning layer and to agglutinate bacteria. This property may enhance surface biofouling. However, both proton nuclear magnetic resonance (NMR) spectra and the nitrogen/carbon (N/C) ratios suggested that the algal TEP/TEP precursors contained much less protein content than the bacterial TEP/TEP precursors. This difference may influence their initial deposition and further development of surface biofouling.

  13. Comparative study of carbonic anhydrase activity in waters among different geological eco-environments of Yangtze River basin and its ecological significance.

    Science.gov (United States)

    Nzung'a, Sila Onesmus; Pan, Weizhi; Shen, Taiming; Li, Wei; Qin, Xiaoqun; Wang, Chenwei; Zhang, Liankai; Yu, Longjiang

    2018-04-01

    This study provides the presence of carbonic anhydrase (CA) activity in waters of the Yangtze River basin, China, as well as the correlation of CA activity with HCO 3 - concentration and CO 2 sink flux. Different degrees of CA activity could be detected in almost all of the water samples from different geological eco-environments in all four seasons. The CA activity of water samples from karst areas was significantly higher than from non-karst areas (PP3 - concentration (r=0.672, P2 sink flux (r=0.602, P=0.076) in karst areas. This suggests that CA in waters might have a promoting effect on carbon sinks for atmospheric CO 2 in karst river basins. In conditions of similar geological type, higher CA activity was generally detected in water samples taken from areas that exhibited better eco-environments, implying that the CA activity index of waters could be used as an indicator for monitoring ecological environments and protection of river basins. These findings suggest that the role of CA in waters in the karst carbon sink potential of river basins is worthy of further in-depth studies. Copyright © 2017. Published by Elsevier B.V.

  14. Imparting improvements in electrochemical sensors: evaluation of different carbon blacks that give rise to significant improvement in the performance of electroanalytical sensing platforms

    International Nuclear Information System (INIS)

    Vicentini, Fernando Campanhã; Ravanini, Amanda E.; Figueiredo-Filho, Luiz C.S.; Iniesta, Jesús; Banks, Craig E.; Fatibello-Filho, Orlando

    2015-01-01

    Three different carbon black materials have been evaluated as a potential modifier, however, only one demonstrated an improvement in the electrochemical properties. The carbon black structures were characterised with SEM, XPS and Raman spectroscopy and found to be very similar to that of amorphous graphitic materials. The modifications utilised were constructed by three different strategies (using ultrapure water, chitosan and dihexadecylphosphate). The fabricated sensors are electrochemically characterised using N,N,N',N'-tetramethyl-para-phenylenediamine and both inner-sphere and outer-sphere redox probes, namely potassium ferrocyanide(II) and hexaammineruthenium(III) chloride, in addition to the biologically relevant and electroactive analytes, dopamine (DA) and acetaminophen (AP). Comparisons are made with an edge-plane pyrolytic graphite and glassy-carbon electrode and the benefits of carbon black implemented as a modifier for sensors within electrochemistry are explored, as well as the characterisation of their electroanalytical performances. We reveal significant improvements in the electrochemical performance (excellent sensitivity, faster heterogeneous electron transfer rate (HET)) over that of a bare glassy-carbon and edge-plane pyrolytic graphite electrode and thus suggest that there are substantial advantages of using carbon black as modifier in the fabrication of electrochemical based sensors. Such work is highly important and informative for those working in the field of electroanalysis where electrochemistry can provide portable, rapid, reliable and accurate sensing protocols (bringing the laboratory into the field), with particular relevance to those searching for new electrode materials

  15. Significant differe nces in demographic, clinical, and pathological features in relation to smoking and alcohol consumption among 1,633 head and neck cancer patients

    Directory of Open Access Journals (Sweden)

    Raquel Ajub Moyses

    2013-06-01

    Full Text Available OBJECTIVE: As a lifestyle-related disease, social and cultural disparities may influence the features of squamous cell carcinoma of the head and neck in different geographic regions. We describe demographic, clinical, and pathological aspects of squamous cell carcinoma of the head and neck according to the smoking and alcohol consumption habits of patients in a Brazilian cohort. METHODS: We prospectively analyzed the smoking and alcohol consumption habits of 1,633 patients enrolled in five São Paulo hospitals that participated in the Brazilian Head and Neck Genome Project - Gencapo. RESULTS: The patients who smoked and drank were younger, and those who smoked were leaner than the other patients, regardless of alcohol consumption. The non-smokers/non-drinkers were typically elderly white females who had more differentiated oral cavity cancers and fewer first-degree relatives who smoked. The patients who drank presented significantly more frequent nodal metastasis, and those who smoked presented less-differentiated tumors. CONCLUSIONS: The patients with squamous cell carcinoma of the head and neck demonstrated demographic, clinical, and pathological features that were markedly different according to their smoking and drinking habits. A subset of elderly females who had oral cavity cancer and had never smoked or consumed alcohol was notable. Alcohol consumption seemed to be related to nodal metastasis, whereas smoking correlated with the degree of differentiation.

  16. Patient-specific positioning guides for total knee arthroplasty: no significant difference between final component alignment and pre-operative digital plan except for tibial rotation.

    Science.gov (United States)

    Boonen, Bert; Schotanus, Martijn G M; Kerens, Bart; Hulsmans, Frans-Jan; Tuinebreijer, Wim E; Kort, Nanne P

    2017-09-01

    To assess whether there is a significant difference between the alignment of the individual femoral and tibial components (in the frontal, sagittal and horizontal planes) as calculated pre-operatively (digital plan) and the actually achieved alignment in vivo obtained with the use of patient-specific positioning guides (PSPGs) for TKA. It was hypothesised that there would be no difference between post-op implant position and pre-op digital plan. Twenty-six patients were included in this non-inferiority trial. Software permitted matching of the pre-operative MRI scan (and therefore calculated prosthesis position) to a pre-operative CT scan and then to a post-operative full-leg CT scan to determine deviations from pre-op planning in all three anatomical planes. For the femoral component, mean absolute deviations from planning were 1.8° (SD 1.3), 2.5° (SD 1.6) and 1.6° (SD 1.4) in the frontal, sagittal and transverse planes, respectively. For the tibial component, mean absolute deviations from planning were 1.7° (SD 1.2), 1.7° (SD 1.5) and 3.2° (SD 3.6) in the frontal, sagittal and transverse planes, respectively. Absolute mean deviation from planned mechanical axis was 1.9°. The a priori specified null hypothesis for equivalence testing: the difference from planning is >3 or plan in all planes, except for the tibial rotation in the transverse plane. Possible explanations for outliers are discussed and highlight the importance for adequate training surgeons before they start using PSPG in their day-by-day practise. Prospective cohort study, Level II.

  17. No significant effect of transcranial direct current stimulation (tDCS) found on simple motor reaction time comparing 15 different simulation protocols.

    Science.gov (United States)

    Horvath, Jared Cooney; Carter, Olivia; Forte, Jason D

    2016-10-01

    Research exploring the behavioral impact of transcranial direct current stimulation (tDCS) over M1 has produced homogenous results. The most common explanations to address this homogeneity concerns the differential impact of varied tDCS parameters (such as stimulation intensity or electrode montage). To explore this, we systematically examined the effects of 15 different tDCS protocols on a well-elucidated neurobehavioral system: simple visual motor reaction time (smRT). For the initial phase of this study, 150 healthy participants were randomly assigned to one of 5 experimental groups (2mA anodal, 2mA cathodal, 1mA anodal, 1mA cathodal, or sham) across 3 different conditions (orbitofrontal, bilateral, or extracephalic reference electrode location). The active electrode was always placed over M1 and tDCS lasted for 20min. Starting ~5min prior to stimulation and running continuously for ~30min, participants were repeatedly presented with a visual cue centered on a computer monitor and asked to press a response button as quickly as possible at stimulus onset (stimuli number: 100 pre-, 400 during-, and 100-post stimulation - interstimulus interval: 1-3s). Ex-gaussian distribution curves, miss, and error rates were determined for each normalized batch of 100 RTs and compared using a two-way ANOVA. As the largest group differences were seen with 2mA anodal (compared to sham) stimulation using an orbitofrontal montage, an additional 60 healthy participants were recruited to further test for significance in this condition. No significant impact of tDCS was seen on any parameter of smRT distribution, error rate, or miss rate, regardless of polarity, stimulation intensity, electrode montage, or stimulation-to-task relationship. Our results suggest that tDCS over M1 might not have a predictable or reliable effect on short duration smRT. Our results raise interesting questions regarding the mechanisms by which tDCS might modulate more complex motor behaviors. Additional

  18. Soil biogeochemistry properties vary between two boreal forest ecosystems in Quebec: significant differences in soil carbon, available nutrients and iron and aluminium crystallinity

    Science.gov (United States)

    Bastianelli, Carole; Ali, Adam A.; Beguin, Julien; Bergeron, Yves; Grondin, Pierre; Hély, Christelle; Paré, David

    2017-04-01

    At the northernmost extent of the managed forest in Quebec, the boreal forest is currently undergoing an ecological transition from closed-canopy black spruce-moss forests towards open-canopy lichen woodlands, which spread southward. Our study aim was to determine whether this shift could impact soil properties on top of its repercussions on forest productivity or carbon storage. We studied the soil biogeochemical composition of three pedological layers in moss forests (MF) and lichen woodlands (LW) north of the Manicouagan crater in Quebec. The humus layer (FH horizons) was significantly thicker and held more carbon, nitrogen and exchangeable Ca and Mg in MF plots than in LW plots. When considering mineral horizons, we found that the deep C horizon had a very close composition in both ecosystem plots, suggesting that the parent material was of similar geochemical nature. This was expected as all selected sites developed from glacial deposit. Multivariate analysis of surficial mineral B horizon showed however that LW B horizon displayed higher concentrations of Al and Fe oxides than MF B horizon, particularly for inorganic amorphous forms. Conversely, main exchangeable base cations (Ca, Mg) were higher in B horizon of MF than that of LW. Ecosystem types explained much of the variations in the B horizon geochemical composition. We thus suggest that the differences observed in the geochemical composition of the B horizon have a biological origin rather than a mineralogical origin. We also showed that total net stocks of carbon stored in MF soils were three times higher than in LW soils (FH + B horizons, roots apart). Altogether, we suggest that variations in soil properties between MF and LW are linked to a cascade of events involving the impacts of natural disturbances such as wildfires on forest regeneration that determines the of vegetation structure (stand density) and composition (ground cover type) and their subsequent consequences on soil environmental

  19. Hardmetals - microstructural design, testing and property maps

    Energy Technology Data Exchange (ETDEWEB)

    Roebuck, B; Gee, M G; Morrell, R [NPL Materials Centre, National Physical Laboratory, Teddington, Middlesex (United Kingdom)

    2001-07-01

    The production of WC/Co hardmetals and their analogues is considered a mature technology, however lately there has been new research results where the concept of microstructural design was used to produce alternatives to the conventional two-phase structure. This Industry is currently well served by a range of baseline established standards, which, if properly followed with good attention to correct quality procedures, will ensure consistent products. However, there are certain key properties such as corrosion, fatigue, impact wear or high temperature strength and toughness that are often measured but not always by standard tests methods. Microstructural design potential is reviewed, particularly the possibilities of performance improvement via changes in size, shape and distribution of the phases as well as recent developments in testing, specifically S-N fatigue and abrasive wear. Finally, the concept of property mapping is introduced as a tool for providing a framework for optimizing properties. Its utility in correlating performance properties and their relationships with microstructural parameters is evaluated. Two property maps are discussed: one where the property is plotted against a microstructural feature (microstructure property maps) such as WC grain size or Co binder phase content against coercivity or hardness and one where different properties, such as hardness and toughness are mapped against each other (comparative property maps). (nevyjel)

  20. Hardmetals - microstructural design, testing and property maps

    International Nuclear Information System (INIS)

    Roebuck, B.; Gee, M.G.; Morrell, R.

    2001-01-01

    The production of WC/Co hardmetals and their analogues is considered a mature technology, however lately there has been new research results where the concept of microstructural design was used to produce alternatives to the conventional two-phase structure. This Industry is currently well served by a range of baseline established standards, which, if properly followed with good attention to correct quality procedures, will ensure consistent products. However, there are certain key properties such as corrosion, fatigue, impact wear or high temperature strength and toughness that are often measured but not always by standard tests methods. Microstructural design potential is reviewed, particularly the possibilities of performance improvement via changes in size, shape and distribution of the phases as well as recent developments in testing, specifically S-N fatigue and abrasive wear. Finally, the concept of property mapping is introduced as a tool for providing a framework for optimizing properties. Its utility in correlating performance properties and their relationships with microstructural parameters is evaluated. Two property maps are discussed: one where the property is plotted against a microstructural feature (microstructure property maps) such as WC grain size or Co binder phase content against coercivity or hardness and one where different properties, such as hardness and toughness are mapped against each other (comparative property maps). (nevyjel)

  1. Studying Microstructure in Molecular Crystals With Nanoindentation

    DEFF Research Database (Denmark)

    Mishra, Manish Kumar; Desiraju, Gautam R; Ramamurty, Upadrasta

    2014-01-01

    Intergrowth polymorphism refers to the existence of distinct structural domains within a single crystal of a compound. The phenomenon is exhibited by form II of the active pharmaceutical ingredient felodipine, and the associated microstructure is a significant feature of the compound's structural...

  2. Characterization of TiN, TiC and Ti(C,N) in titanium-alloyed ferritic chromium steels focusing on the significance of different particle morphologies

    Energy Technology Data Exchange (ETDEWEB)

    Michelic, S.K., E-mail: susanne.michelic@unileoben.ac.at [Chair of Ferrous Metallurgy, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria); Loder, D. [Chair of Ferrous Metallurgy, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria); Reip, T.; Ardehali Barani, A. [Outokumpu Nirosta GmbH, Essener Straße 244, 44793 Bochum (Germany); Bernhard, C. [Chair of Ferrous Metallurgy, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria)

    2015-02-15

    Titanium-alloyed ferritic chromium steels are a competitive option to classical austenitic stainless steels owing to their similar corrosion resistance. The addition of titanium significantly influences their final steel cleanliness. The present contribution focuses on the detailed metallographic characterization of titanium nitrides, titanium carbides and titanium carbonitrides with regard to their size, morphology and composition. The methods used are manual and automated Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy as well as optical microscopy. Additional thermodynamic calculations are performed to explain the precipitation procedure of the analyzed titanium nitrides. The analyses showed that homogeneous nucleation is decisive at an early process stage after the addition of titanium. Heterogeneous nucleation gets crucial with ongoing process time and essentially influences the final inclusion size of titanium nitrides. A detailed investigation of the nuclei for heterogeneous nucleation with automated Scanning Electron Microscopy proved to be difficult due to their small size. Manual Scanning Electron Microscopy and optical microscopy have to be applied. Furthermore, it was found that during solidification an additional layer around an existing titanium nitride can be formed which changes the final inclusion morphology significantly. These layers are also characterized in detail. Based on these different inclusion morphologies, in combination with thermodynamic results, tendencies regarding the formation and modification time of titanium containing inclusions in ferritic chromium steels are derived. - Graphical abstract: Display Omitted - Highlights: • The formation and modification of TiN in the steel 1.4520 was examined. • Heterogeneous nucleation essentially influences the final steel cleanliness. • In most cases heterogeneous nuclei in TiN inclusions are magnesium based. • Particle morphology provides important information

  3. Cross-national differences in clinically significant cannabis problems: epidemiologic evidence from 'cannabis-only' smokers in the United States, Mexico, and Colombia

    Directory of Open Access Journals (Sweden)

    Posada-Villa Jose

    2010-03-01

    Full Text Available Abstract Background Epidemiological studies show wide variability in the occurrence of cannabis smoking and related disorders across countries. This study aims to estimate cross-national variation in cannabis users' experience of clinically significant cannabis-related problems in three countries of the Americas, with a focus on cannabis users who may have tried alcohol or tobacco, but who have not used cocaine, heroin, LSD, or other internationally regulated drugs. Methods Data are from the World Mental Health Surveys Initiative and the National Latino and Asian American Study, with probability samples in Mexico (n = 4426, Colombia (n = 5,782 and the United States (USA; n = 8,228. The samples included 212 'cannabis only' users in Mexico, 260 in Colombia and 1,724 in the USA. Conditional GLM with GEE and 'exact' methods were used to estimate variation in the occurrence of clinically significant problems in cannabis only (CO users across these surveyed populations. Results The experience of cannabis-related problems was quite infrequent among CO users in these countries, with weighted frequencies ranging from 1% to 5% across survey populations, and with no appreciable cross-national variation in general. CO users in Colombia proved to be an exception. As compared to CO users in the USA, the Colombia smokers were more likely to have experienced cannabis-associated 'social problems' (odds ratio, OR = 3.0; 95% CI = 1.4, 6.3; p = 0.004 and 'legal problems' (OR = 9.7; 95% CI = 2.7, 35.2; p = 0.001. Conclusions This study's most remarkable finding may be the similarity in occurrence of cannabis-related problems in this cross-national comparison within the Americas. Wide cross-national variations in estimated population-level cumulative incidence of cannabis use disorders may be traced to large differences in cannabis smoking prevalence, rather than qualitative differences in cannabis experiences. More research is needed to identify conditions that

  4. Effect of Microstructure Constraints on the Homogenized Elastic Constants of Elastomeric Sylgard/GMB Syntactic Foam.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Judith Alice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Steck, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brown, Judith Alice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Long, Kevin Nicholas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    Previous numerical studies of Sylgard filled with glass microballoons (GMB) have relied on various microstructure idealizations to achieve a large range of volume fractions with high mesh quality. This study investigates how different microstructure idealizations and constraints affect the apparent homogenized elastic constants in the virgin state of the material, in which all GMBs are intact and perfectly bonded to the Sylgard matrix, and in the fully damaged state of the material in which all GMBs are destroyed. In the latter state, the material behaves as an elastomeric foam. Four microstructure idealizations are considered relating to how GMBs are packed into a representative volume element (RVE): (1) no boundary penetration nor GMB-GMB overlap, (2) GMB-GMB overlap, (3) boundary penetration, and (4) boundary penetration and GMB-GMB overlap. First order computational homogenization with kinematically uniform displacement boundary conditions (KUBCs) was employed to determine the homogenized (apparent) bulk and shear moduli for the four microstructure idealizations in the intact and fully broken GMB material states. It was found that boundary penetration has a significant effect on the shear modulus for microstructures with intact GMBs, but that neither boundary penetration nor GMB overlap have a significant effect on homogenized properties for microstructures with fully broken GMBs. The primary conclusion of the study is that future investigations into Sylgard/GMB micromechanics should either force GMBs to stay within the RVE fully and/or use periodic BCs (PBCs) to eliminate the boundary penetration issues. The implementation of PBCs requires the improvement of existing tools in Sandia’s Sierra/SM code.

  5. Bile salt receptor TGR5 is highly expressed in esophageal adenocarcinoma and precancerous lesions with significantly worse overall survival and gender differences

    Directory of Open Access Journals (Sweden)

    Pang CH

    2017-02-01

    Full Text Available Chunhong Pang,1,2 Amy LaLonde,3 Tony E Godfrey,4 Jianwen Que,5,6 Jun Sun,7 Tong Tong Wu,3 Zhongren Zhou2 1Department of Pathology, China-Japan Friendship Hospital, 2Department of Pathology and Laboratory Medicine, 3Department of Biostatistics and Computational Biology, University of Rochester, Rochester, NY, 4Department of Surgery, Boston University Medical Center, Boston, MA, 5Center for Human Development, 6Division of Digestive and Liver Diseases, Columbia University, New York, NY, 7Division of Gastroenterology and Hepatology, University of Illinois College of Medicine, Chicago, IL, USA Abstract: Bile acid reflux in the esophagus plays an important role in the carcinogenesis of esophageal adenocarcinoma (EAC. The G-protein coupled bile acid receptor (TGR5 has been associated with the development of gastrointestinal cancer. However, little is known regarding the role of TGR5 in esophageal carcinoma and precancerous lesions. We analyzed genomic DNA from 116 EACs for copy number aberrations via Affymetrix SNP6.0 microarrays. The TGR5 gene locus was amplified in 12.7% (14/116 of the EACs. The TGR5 protein expression was also assessed using immunohistochemistry from tissue microarrays, including Barrett’s esophagus (BE, low- (LGD and high-grade dysplasia (HGD, columnar cell metaplasia (CM, squamous epithelium (SE, EAC and squamous cell carcinoma. The TGR5 protein was highly expressed in 71% of EAC (75/106, 100% of HGD (11/11, 72% of LGD (13/18, 66% of BE (23/35, 84% of CM (52/62, and 36% of SE (30/83. The patients with high expression of TGR5 exhibited significantly worse overall survival compared to the patients with nonhigh expression. TGR5 high expression was significantly increased in the males compared to the females in all cases with an odds ratio of 1.9 times. The vitamin D receptor (VDR was significantly correlated with TGR5 expression. Our findings indicated that TGR5 may play an important role in the development and prognosis of EAC

  6. [Microstructural changes in hardened beans (Phaseolus vulgaris)].

    Science.gov (United States)

    Mujica, Maria Virginia; Granito, Marisela; Soto, Naudy

    2015-06-01

    (Phaseolus vulgaris). The hardening of Phaseolus vulgaris beans stored at high temperature and high relative humidity is one of the main constraints for consumption. The objective of this research was to evaluate by scanning electron microscopy, structural changes in cotyledons and testa of the hardened beans. The freshly harvested grains were stored for twelve months under two conditions: 5 ° C-34% RH and 37 ° C-75% RH, in order to promote hardening. The stored raw and cooked grains were lyophilized and fractured. The sections of testa and cotyledons were observed in an electron microscope JSM-6390. After twelve months, grains stored at 37 ° C-75% RH increased their hardness by 503%, whereas there were no significant changes in grains stored at 5 ° C-34% RH. At the microstructural level, the cotyledons of the raw grains show clear differences in appearance of the cell wall, into the intercellular space size and texture matrix protein. There were also differences in compaction of palisade and sub-epidermal layer in the testa of raw grains. After cooking, cotyledon cells of the soft grains were well separated while these ofhard grains were seldom separated. In conclusion, the found differences in hard and soft grains showed a significant participation of both structures, cotyledons and testa, in the grains hardening.

  7. A study of the composition and microstructure of nanodispersed Cu-Ni alloys obtained by different routes from copper and nickel oxides

    Energy Technology Data Exchange (ETDEWEB)

    Cangiano, Maria de los A; Ojeda, Manuel W., E-mail: mojeda@unsl.edu.ar; Carreras, Alejo C.; Gonzalez, Jorge A.; Ruiz, Maria del C

    2010-11-15

    Mixtures of CuO and NiO were prepared by two different techniques, and then the oxides were reduced with H{sub 2}. Method A involved the preparation of mechanical mixtures of CuO and NiO using different milling and pelletizing processes. Method B involved the chemical synthesis of the mixture of CuO and NiO. The route used to prepare the copper and nickel oxide mixture was found to have great influence on the characteristics of bimetallic Cu-Ni particles obtained. Observations performed using the X-ray diffraction (XRD) technique showed that although both methods led to the Cu-Ni solid solution, the diffractogram of the alloy obtained with method A revealed the presence of NiO together with the alloy. The temperature-programmed reduction (TPR) experiments indicated that the alloy is formed at lower temperatures when using method B. The scanning electron microscopy (SEM) studies revealed notable differences in the morphology and size distribution of the bimetallic particles synthesized by different routes. The results of the electron probe microanalysis (EPMA) studies evidenced the existence of a small amount of oxygen in both cases and demonstrated that the alloy synthesized using method B presented a homogeneous composition with a Cu-Ni ratio close to 1:1. On the contrary, the alloy obtained using method A was not homogeneous in all the volume of the solid. The homogeneity depended on the mechanical treatment undergone by the mixture of the oxides. - Research Highlights: {yields}Study of the properties of Cu-Ni alloys synthesized by two different routes. {yields}Mixtures of Cu and Ni oxides prepared by two techniques were reduced with H{sub 2}. {yields}Mixtures of oxides were obtained by a mechanical process and the citrate-gel route. {yields}The characterizations were carried out by TPR, XRD, SEM and EPMA. {yields}The route used to prepare oxide mixtures influences on the Cu-Ni alloy obtained.

  8. A study of the composition and microstructure of nanodispersed Cu-Ni alloys obtained by different routes from copper and nickel oxides

    International Nuclear Information System (INIS)

    Cangiano, Maria de los A; Ojeda, Manuel W.; Carreras, Alejo C.; Gonzalez, Jorge A.; Ruiz, Maria del C

    2010-01-01

    Mixtures of CuO and NiO were prepared by two different techniques, and then the oxides were reduced with H 2 . Method A involved the preparation of mechanical mixtures of CuO and NiO using different milling and pelletizing processes. Method B involved the chemical synthesis of the mixture of CuO and NiO. The route used to prepare the copper and nickel oxide mixture was found to have great influence on the characteristics of bimetallic Cu-Ni particles obtained. Observations performed using the X-ray diffraction (XRD) technique showed that although both methods led to the Cu-Ni solid solution, the diffractogram of the alloy obtained with method A revealed the presence of NiO together with the alloy. The temperature-programmed reduction (TPR) experiments indicated that the alloy is formed at lower temperatures when using method B. The scanning electron microscopy (SEM) studies revealed notable differences in the morphology and size distribution of the bimetallic particles synthesized by different routes. The results of the electron probe microanalysis (EPMA) studies evidenced the existence of a small amount of oxygen in both cases and demonstrated that the alloy synthesized using method B presented a homogeneous composition with a Cu-Ni ratio close to 1:1. On the contrary, the alloy obtained using method A was not homogeneous in all the volume of the solid. The homogeneity depended on the mechanical treatment undergone by the mixture of the oxides. - Research Highlights: →Study of the properties of Cu-Ni alloys synthesized by two different routes. →Mixtures of Cu and Ni oxides prepared by two techniques were reduced with H 2 . →Mixtures of oxides were obtained by a mechanical process and the citrate-gel route. →The characterizations were carried out by TPR, XRD, SEM and EPMA. →The route used to prepare oxide mixtures influences on the Cu-Ni alloy obtained.

  9. Microstructured optical fibers - Fundamentals and applications

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Bjarklev, Anders Overgaard

    2006-01-01

    In recent years optical fibers having a complex microstructure in the transverse plane have attracted much attention from both researchers and industry. Such fibers can either guide light through total internal reflection or the photonic bandgap effect. Among the many unique applications offered...... by these fibers are mode guidance in air, highly flexible dispersion engineering, and the use of very heterogeneous material combinations. In this paper, we review the different types and applications of microstructured optical fibers, with particular emphasis on recent advances in the field....

  10. Microstructure evolution of titanium after tensile test

    International Nuclear Information System (INIS)

    Wronski, S.; Wierzbanowski, K.; Jędrychowski, M.; Tarasiuk, J; Wronski, M.; Baczmanski, A.; Bacroix, B.

    2016-01-01

    The qualitative and quantitative behavior of titanium T40 during tensile loading with a special emphasis on the presence of deformation twins in the observed microstructures is described. The samples for tensile tests were cut out from the rolled titanium sheet along the rolling and transverse directions. Several microstructure maps were determined using Electron Backscatter Diffraction technique (EBSD). These data were used to obtain crystallographic textures, misorientation distributions, grain size, twin boundary length, grain orientation spread, low and high angle boundary fractions and Schmid and Taylor factors. The deformation mechanisms and microstructure characteristics are different in the samples stretched along rolling and transverse directions. A strong appearance of tensile twins was observed in the samples deformed along transverse direction. On the other hand, more frequent subgrain formation and higher orientation spread was observed in the sample deformed along rolling direction, which caused’‘orientation blurring’ leading to an increase of grain size with deformation, as determined from OIM analysis.

  11. The temporoammonic input to the hippocampal CA1 region displays distinctly different synaptic plasticity compared to the Schaffer collateral input in vivo: significance for synaptic information processing

    Directory of Open Access Journals (Sweden)

    Ayla eAksoy Aksel

    2013-08-01

    Full Text Available In terms of its sub-regional differentiation, the hippocampal CA1 region receives cortical information directly via the perforant (temporoammonic path (pp-CA1 synapse and indirectly via the tri-synaptic pathway where the last relay station is the Schaffer collateral-CA1 synapse (Sc-CA1 synapse. Research to date on pp-CA1 synapses has been conducted predominantly in vitro and never in awake animals, but these studies hint that information processing at this synapse might be distinct to processing at the Sc-CA1 synapse. Here, we characterized synaptic properties and synaptic plasticity at the pp-CA1 synapse of freely behaving adult rats. We established that field excitatory postsynaptic potentials at the pp-CA1 have longer onset latencies and a shorter time-to-peak compared to the Sc-CA1 synapse. LTP (> 24h was successfully evoked by tetanic afferent stimulation of pp-CA1 synapses. Low frequency stimulation evoked synaptic depression at Sc-CA1 synapses, but did not elicit LTD at pp-CA1 synapses unless the Schaffer collateral afferents to the CA1 region had been severed. Paired-pulse responses also showed significant differences. Our data suggest that synaptic plasticity at the pp-CA1 synapse is distinct from the Sc-CA1 synapse and that this may reflect its specific role in hippocampal information processing.

  12. Microstructural studies of La10.7Ca0.3MnO3 (LCMO) films on different (110) substrates deposited by pulsed laser deposition

    International Nuclear Information System (INIS)

    Tse, Y Y; Jones, I P; Chakalov, R I; Muirhead, C M; Palai, R; Huhtinen, H

    2008-01-01

    La 0.7 Ca 0.3 MnO 3 (LCMO) films grown on (110) surfaces of various (pseudo-) cubic substrates, SrTiO 3 (STO), LaAlO 3 (LAO) and La 0.3 Sr 0.7 Al 0.5 Ta 0.35 O 3 (LSAT), were studied by means of transmission electron microscopy (TEM). (110) LSAT substrate and LCMO film have the smallest lattice mismatch. (110) LAO substrate induces compressive strain while (110) STO induces tensile strain in the LCMO film. In all cases, the (010) 0 plane (long axis) of LCMO is parallel to the substrate surface. In the case of LSAT, the [001] 0 is parallel to [011] LSAT while the films on the other 2 substrates have [100] 0 // to the [011] substrates. Films grown on STO and LAO show an easy magnetisation when the applied magnetic field is in plane along the long-axis of the LCMO. In the case of LSAT, there is no in-plane anisotropy. The films on STO and LAO have twins as the dominant defects. The film on LSAT has less twining. High resolution TEM shows that LCMO on (110) LSAT (the least lattice mismatch) possesses a perfect interface with no misfit dislocations in the area of examination. The LCMO films on (110) LAO and (110) STO have nearly perfect interfaces with atomic sharpness but with misfit dislocations. The different in-plane crystal directions and strain distributions in the films may account for the different magnetisation behaviours of the LCMO films on the different (011) substrates.

  13. Microstructure and transformation kinetics in bainitic steels

    NARCIS (Netherlands)

    Luzginova, N.V.

    2008-01-01

    With the aim of reaching a better understanding of the microstructure evolution and the overall phase transformation kinetics in hyper-eutectoid steels a commercial SAE 52100 bearing steel and 7 model alloys with different concentrations of chromium, cobalt and aluminum have been studied in this

  14. Cellular automaton simulation of microstructure evolution during ...

    Indian Academy of Sciences (India)

    Unknown

    different composition and austenite grain size. Using the ..... Figure 1. Microstructures of 0⋅28% C steel heat treated samples: a. cooling rate 1⋅75°C/S and equivalent grain diameter .... qualitative predictions point to the essential soundness.

  15. Microstructural characterization of stone wool fibre network

    DEFF Research Database (Denmark)

    Chapelle, Lucie; Brøndsted, Povl; Kusano, Yukihiro

    2014-01-01

    Understanding the mechanical properties of fibrous network as complex as stone wool materials requires a relevant description of their microstructure and architecture. In this study, different methods have been proposed to characterize the fibre orientation, diameter and length of fibres as well...

  16. Biochemical and microstructural characteristics of meat samples ...

    African Journals Online (AJOL)

    This study was conducted to compare the efficiency of different plant proteases for changing biochemical and microstructural characteristics in muscle foods. The meat samples from chicken, giant catfish, pork and beef were treated with four types of proteolytic enzymes: Calotropis procera latex proteases, papaya latex ...

  17. Microstructural characterization of materials by neural network technique

    Energy Technology Data Exchange (ETDEWEB)

    Barat, P. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India); Chatterjee, A., E-mail: arnomitra@veccal.ernet.i [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India); Mukherjee, P.; Gayathri, N. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India); Jayakumar, T.; Raj, Baldev [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2010-11-15

    Ultrasonic signals received by pulse echo technique from plane parallel Zircaloy 2 samples of fixed thickness and of three different microstructures, were subjected to signal analysis, as conventional parameters like velocity and attenuation could not reliably discriminate them. The signals, obtained from these samples, were first sampled and digitized. Modified Karhunen Loeve Transform was used to reduce their dimensionality. A multilayered feed forward Artificial Neural Network was trained using a few signals in their reduced domain from the three different microstructures. The rest of the signals from the three samples with different microstructures were classified satisfactorily using this network.

  18. Microstructure and cross-sectional shape of limb bones in Great Horned Owls and Red-tailed Hawks: how do these features relate to differences in flight and hunting behavior?

    Science.gov (United States)

    Marelli, Crystal A; Simons, Erin L R

    2014-01-01

    The Red-tailed Hawk and Great Horned Owl are two species of raptor that are similar in body size, diet, and habitat. Both species use their hindlimbs during hunting, but differ in foot morphology, how they approach and immobilize prey, and the average size of prey captured. They also differ in primary flight style: the Red-tailed Hawk uses static soaring and the Great Horned Owl uses flap-gliding. The objectives of this study were to characterize the microstructure and cross-sectional shape of limb bones of these species and examine the relationship with flight and hunting behaviors. The mid-shaft of six limb bones from six individuals of each species was sampled. The degree of bone laminarity (proportion of circular primary vascular canals) and cross-sectional geometric parameters were calculated. In both species, the humerus and femur exhibited features that suggest high resistance to torsional loading, whereas the tibiotarsus and phalanges had a shape more likely to resist compression and bending in a specific plane. The femur of the Red-tailed Hawk exhibited higher laminarity and larger polar moment of area than that of the Great Horned Owl. The tibiotarsus was more elliptical than that of the Great Horned Owl. The hawk approaches prey from a more horizontal axis, takes prey of greater mass, and is more likely to pursue prey on the ground, which could potentially be causing more torsional loads on the femur and bending loads on the tibiotarsus. In addition, differences in polar moment of area of the phalanges between the species could relate to differences in foot morphology or digit length. The humerus and ulna of the flap-gliding Great Horned Owl are more elliptical than the static soaring Red-tailed Hawk, a shape that may better resist the bending loads associated with a larger amount of flapping.

  19. Microstructure, Tensile Adhesion Strength and Thermal Shock Resistance of TBCs with Different Flame-Sprayed Bond Coat Materials Onto BMI Polyimide Matrix Composite

    Science.gov (United States)

    Abedi, H. R.; Salehi, M.; Shafyei, A.

    2017-10-01

    In this study, thermal barrier coatings (TBCs) composed of different bond coats (Zn, Al, Cu-8Al and Cu-6Sn) with mullite top coats were flame-sprayed and air-plasma-sprayed, respectively, onto bismaleimide matrix composites. These polyimide matrix composites are of interest to replace PMR-15, due to concerns about the toxicity of the MDA monomer from which PMR-15 is made. The results showed that pores and cracks appeared at the bond coat/substrate interface for the Al-bonded TBC because of its high thermal conductivity and diffusivity resulting in transferring of high heat flux and temperature to the polymeric substrate during top coat deposition. The other TBC systems due to the lower conductivity and diffusivity of bonding layers could decrease the adverse thermal effect on the polymer substrate during top coat deposition and exhibited adhesive bond coat/substrate interfaces. The tensile adhesion test showed that the adhesion strength of the coatings to the substrate is inversely proportional to the level of residual stress in the coatings. However, the adhesion strength of Al bond-coated sample decreased strongly after mullite top coat deposition due to thermal damage at the bond coat/substrate interface. TBC system with the Cu-6Sn bond coat exhibited the best thermal shock resistance, while Al-bonded TBC showed the lowest. It was inferred that thermal mismatch stresses and oxidation of the bond coats were the main factors causing failure in the thermal shock test.

  20. Explanation of Significant Differences for the Record of Decision for Interim Actions in Zone 1, East Tennessee Technology Park, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel Jacobs

    2011-02-01

    Zone 1 is a 1400-acre area outside the fence of the main plant at The East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. The Record of Decision for Interim Actions in Zone, ETTP (Zone 1 Interim ROD) (DOE 2002) identifies the remedial actions for contaminated soil, buried waste, and subsurface infrastructure necessary to protect human health and to limit further contamination of groundwater. Since the Zone 1 Interim Record of Decision (ROD) was signed, new information has been obtained that requires the remedy to be modified as follows: (1) Change the end use in Contractor's Spoil Area (CSA) from unrestricted industrial to recreational; (2) Remove Exposure Units (EU5) ZI-50, 51, and 52 from the scope of the Zone I Interim ROD; (3) Change the end use of the duct bank corridor from unrestricted industrial to restricted industrial; and (4) Remove restriction for the disturbance of soils below 10 feet in Exposure Unit (EU) Z1-04. In accordance with 40 Code of Federal Regulations (CFR) 300.435, these scope modifications are a 'significant' change to the Zone 1 Interim ROD. In accordance with CERCLA Sect. 117 (c) and 40 CFR 300.435 (c)(2)(i), such a significant change is documented with an Explanation of Significant Differences (ESD). The purpose of this ESD is to make the changes listed above. This ESD is part of the Administrative Record file, and it, and other information supporting the selected remedy, can be found at the DOE Information Center, 475 Oak Ridge Turnpike, Oak Ridge, Tennessee 37830, from 8:00 a.m. to 5:00 p.m., Monday through Friday. The ORR is located in Roane and Anderson counties, within and adjacent to the corporate city limits of Oak Ridge, Tennessee. ETTP is located in Roane County near the northwest corner of the ORR. ETTP began operation during World War II as part of the Manhattan Project. The original mission of ETTP was to produce enriched uranium for use in atomic weapons. The plant produced enriched uranium from

  1. Effects of white matter microstructure on phase and susceptibility maps.

    Science.gov (United States)

    Wharton, Samuel; Bowtell, Richard

    2015-03-01

    To investigate the effects on quantitative susceptibility mapping (QSM) and susceptibility tensor imaging (STI) of the frequency variation produced by the microstructure of white matter (WM). The frequency offsets in a WM tissue sample that are not explained by the effect of bulk isotropic or anisotropic magnetic susceptibility, but rather result from the local microstructure, were characterized for the first time. QSM and STI were then applied to simulated frequency maps that were calculated using a digitized whole-brain, WM model formed from anatomical and diffusion tensor imaging data acquired from a volunteer. In this model, the magnitudes of the frequency contributions due to anisotropy and microstructure were derived from the results of the tissue experiments. The simulations suggest that the frequency contribution of microstructure is much larger than that due to bulk effects of anisotropic magnetic susceptibility. In QSM, the microstructure contribution introduced artificial WM heterogeneity. For the STI processing, the microstructure contribution caused the susceptibility anisotropy to be significantly overestimated. Microstructure-related phase offsets in WM yield artifacts in the calculated susceptibility maps. If susceptibility mapping is to become a robust MRI technique, further research should be carried out to reduce the confounding effects of microstructure-related frequency contributions. © 2014 Wiley Periodicals, Inc.

  2. Effect of different dietary energy and protein sources on antioxidant status, fresh yolk fatty acid profile and microstructure of salted yolks in laying ducks.

    Science.gov (United States)

    Ruan, D; Hu, Y J; Fouad, A M; Lin, C X; Xu, Z P; Chen, W; Fan, Q L; Xia, W G; Wang, S; Wang, Y; Yang, L; Zheng, C T

    2018-01-08

    The study investigated whether different dietary energy and protein sources affect laying performance, antioxidant status, fresh yolk fatty acid profile and quality of salted yolks in laying ducks. In all, 360 19-week-old Longyan ducks were randomly assigned to four diets in a factorial arrangement (2×2). The four diets consisted of two energy sources, corn (CO) or sorghum (SO) and two protein sources, soybean meal (SM) and rapeseed meal with corn distillers dried grains with solubles (RMD), and each treatment contained six replicates of 15 birds each. The experimental diets were isocaloric (metabolizable energy, 10.84 MJ/kg) and isonitrogenous (CP, 17%). The results showed that egg production, average egg weight, egg mass and feed conversion ratio were not affected by diets (P>0.05). Plasma contents of reduced glutathione (GSH), GSH/oxidized glutathione and total antioxidant capacity were lower (P<0.05) in ducks fed the RMD diets compared with those fed SM diets with a substantial increase (P=0.006) in plasma content of malondialdehyde (MDA). Egg yolks from ducks fed SO diets had higher proportions of polyunsaturated fatty acids (PUFA) and lower saturated and monounsaturated fatty acids compared with CO diets (P<0.001). Similarly, ducks fed RMD diets had a higher content of PUFA and n-6/n-3 ratio in fresh yolks (P<0.001), and increased salted yolk MDA, carbonylated proteins content and incidence of hard salted yolks (P<0.05) compared with SM diets. Scanning electron microscopy showed that salted yolks contained rougher polyhedral granules and fewer fat droplets, and were surrounded with a layer of bunchy fibers in ducks fed SO+RMD than those fed CO+SM diet. In conclusion, the current study showed that feeding laying ducks with diets containing SO or RMD reduced antioxidant capacity and increased egg yolk concentrations of PUFA. It appeared that egg yolks from ducks fed these diets were more sensitive to lipid peroxidation and protein oxidation during salting, and

  3. Modelling of deformation and recrystallisation microstructures in rocks and ice

    Science.gov (United States)

    Bons, Paul D.; Evans, Lynn A.; Gomez-Rivas, Enrique; Griera, Albert; Jessell, Mark W.; Lebensohn, Ricardo; Llorens, Maria-Gema; Peternell, Mark; Piazolo, Sandra; Weikusat, Ilka; Wilson, Chris J. L.

    2015-04-01

    Microstructures both record the deformation history of a rock and strongly control its mechanical properties. As microstructures in natural rocks only show the final "post-mortem" state, geologists have attempted to simulate the development of microstructures with experiments and later numerical models. Especially in-situ experiments have given enormous insight, as time-lapse movies could reveal the full history of a microstructure. Numerical modelling is an alternative approach to simulate and follow the change in microstructure with time, unconstrained by experimental limitations. Numerical models have been applied to a range of microstructural processes, such as grain growth, dynamic recrystallisation, porphyroblast rotation, vein growth, formation of mylonitic fabrics, etc. The numerical platform "Elle" (www.elle.ws) in particular has brought progress in the simulation of microstructural development as it is specifically designed to include the competition between simultaneously operating processes. Three developments significantly improve our capability to simulate microstructural evolution: (1) model input from the mapping of crystallographic orientation with EBSD or the automatic fabric analyser, (2) measurement of grain size and crystallographic preferred orientation evolution using neutron diffraction experiments and (3) the implementation of the full-field Fast Fourier Transform (FFT) solver for modelling anisotropic crystal-plastic deformation. The latter enables the detailed modelling of stress and strain as a function of local crystallographic orientation, which has a strong effect on strain localisation such as, for example, the formation of shear bands. These models can now be compared with the temporal evolution of crystallographic orientation distributions in in-situ experiments. In the last decade, the possibility to combine experiments with numerical simulations has allowed not only verification and refinement of the numerical simulation

  4. Utilization of FEM model for steel microstructure determination

    Science.gov (United States)

    Kešner, A.; Chotěborský, R.; Linda, M.; Hromasová, M.

    2018-02-01

    Agricultural tools which are used in soil processing, they are worn by abrasive wear mechanism cases by hard minerals particles in the soil. The wear rate is influenced by mechanical characterization of tools material and wear rate is influenced also by soil mineral particle contents. Mechanical properties of steel can be affected by a technology of heat treatment that it leads to a different microstructures. Experimental work how to do it is very expensive and thanks to numerical methods like FEM we can assumed microstructure at low cost but each of numerical model is necessary to be verified. The aim of this work has shown a procedure of prediction microstructure of steel for agricultural tools. The material characterizations of 51CrV4 grade steel were used for numerical simulation like TTT diagram, heat capacity, heat conduction and other physical properties of material. A relationship between predicted microstructure by FEM and real microstructure after heat treatment shows a good correlation.

  5. A Markov random field approach for microstructure synthesis

    International Nuclear Information System (INIS)

    Kumar, A; Nguyen, L; DeGraef, M; Sundararaghavan, V

    2016-01-01

    We test the notion that many microstructures have an underlying stationary probability distribution. The stationary probability distribution is ubiquitous: we know that different windows taken from a polycrystalline microstructure are generally ‘statistically similar’. To enable computation of such a probability distribution, microstructures are represented in the form of undirected probabilistic graphs called Markov Random Fields (MRFs). In the model, pixels take up integer or vector states and interact with multiple neighbors over a window. Using this lattice structure, algorithms are developed to sample the conditional probability density for the state of each pixel given the known states of its neighboring pixels. The sampling is performed using reference experimental images. 2D microstructures are artificially synthesized using the sampled probabilities. Statistical features such as grain size distribution and autocorrelation functions closely match with those of the experimental images. The mechanical properties of the synthesized microstructures were computed using the finite element method and were also found to match the experimental values. (paper)

  6. Identification of microstructures

    International Nuclear Information System (INIS)

    Padilha, A.F.; Ambrozio Filho, F.

    1984-01-01

    The identification of phases in a material can require the utilization of several techniques. The most used technique and discussed are: optical microscope, scanning electron microscope, transmission electron microscope, X-ray diffraction and 'in-situ' chemical analysis of the phases. The microstructures were classified, in according to the size and phase volumetric fraction, in four types. For each type the most appropriate techniques for identifying the phases are discussed. (E.G.) [pt

  7. Stochastic microstructure characterization and reconstruction via supervised learning

    International Nuclear Information System (INIS)

    Bostanabad, Ramin; Bui, Anh Tuan; Xie, Wei; Apley, Daniel W.; Chen, Wei

    2016-01-01

    Microstructure characterization and reconstruction have become indispensable parts of computational materials science. The main contribution of this paper is to introduce a general methodology for practical and efficient characterization and reconstruction of stochastic microstructures based on supervised learning. The methodology is general in that it can be applied to a broad range of microstructures (clustered, porous, and anisotropic). By treating the digitized microstructure image as a set of training data, we generically learn the stochastic nature of the microstructure via fitting a supervised learning model to it (we focus on classification trees). The fitted supervised learning model provides an implicit characterization of the joint distribution of the collection of pixel phases in the image. Based on this characterization, we propose two different approaches to efficiently reconstruct any number of statistically equivalent microstructure samples. We test the approach on five examples and show that the spatial dependencies within the microstructures are well preserved, as evaluated via correlation and lineal-path functions. The main advantages of our approach stem from having a compact empirically-learned model that characterizes the stochastic nature of the microstructure, which not only makes reconstruction more computationally efficient than existing methods, but also provides insight into morphological complexity.

  8. Effect of microstructure and cutting speed on machining behavior of Ti6Al4V alloy

    Energy Technology Data Exchange (ETDEWEB)

    Telrandhe, Sagar V.; Mishra, Sushil; Saxena, Ashish K. [Indian Institute of Technology Bombay, Mumbai (India)

    2017-05-15

    Machining of aerospace and biomedical grade titanium alloys has always been a challenge because of their low conductivity and elastic modulus. Different machining methods and parameters have been adopted for high precision machining of titanium alloys. Machining of titanium alloys can be improved by microstructure optimization. The present study focuses on the effect of microstructure on ma- chinability of Ti6Al4V alloys at different cutting speeds. Samples were subjected to different annealing conditions resulting in different grain sizes and local micro-strains (misorientation). Cutting forces were significantly reduced after annealing; consequently, sub-surface residual stresses were reduced. Deformation twinning was also observed on samples annealed at a higher temperature due to larger grain size. Initial strain free grains and deformation twinning during machining reduces the cutting force at higher cutting speed.

  9. Altered Sputum Microstructure as a Marker of Airway Obstruction in Cystic Fibrosis Patients

    Science.gov (United States)

    Duncan, Gregg; Jung, James; West, Natalie; Boyle, Michael; Suk, Jung Soo; Hanes, Justin

    In the lungs of cystic fibrosis (CF) patients, highly viscoelastic mucus remains stagnant in the lung leading to obstructed airways prone to recurrent infections. Bulk-fluid rheological measurement is primarily used to assess the pathological features of mucus. However, this approach is limited in detecting microscopic properties on the length scale of pathogens and immune cells. We have shown in prior work based on the transport of muco-inert nanoparticles (MIP) in CF sputum that patients can carry significantly different microstructural properties. In this study, we aimed to determine the factors leading to variations between patients in sputum microstructure and their clinical implications. The microrheological properties of CF sputum were measured using multi-particle tracking experiments of MIP. MIP were made by grafting polyethylene glycol onto the surface of polystyrene nanoparticles which prior work has shown prevents adhesion to CF sputum. Biochemical analyses show that sputum microstructure was significantly altered by elevated mucin and DNA content. Reduction in sputum pore size is characteristic of patients with obstructed airways as indicated by measured pulmonary function tests. Our microstructural read-out may serve as a novel biomarker for CF.

  10. Effects of Ni and Mo on the microstructure and some other properties of Co-Cr dental alloys

    International Nuclear Information System (INIS)

    Matkovic, Tanja; Matkovic, Prosper; Malina, Jadranka

    2004-01-01

    Influences of adding Ni and Mo on the microstructure and properties of as-cast Co-Cr base alloys have been investigated in order to determine the region of their optimal characteristics for biomedical application. The alloys were produced by arc-melting technique under argon atmosphere. Using optical metallography and scanning electron micro analyser it has been established that among 10 samples of Co-Cr-Ni alloys only samples 5 and 9 with the composition Co 55 Cr 40 Ni 5 and Co 60 Cr 30 Ni 10 have appropriate dendritic solidification microstructure. This microstructure, typical for commercial dental alloys, appears and beside greater number of as-cast Co-Cr-Mo alloys. The results of hardness and corrosion resistance measurements revealed the strong influence of different alloy chemistry and of as-cast microstructure. Hardness of alloys decreases with nickel content, but increases with chromium content. Therefore all Co-Cr-Ni alloys have significantly lower hardness than Co-Cr-Mo alloys. Corrosion resistance of alloys in artificial saliva was evaluated on the base of pitting potential. Superior corrosion characteristics have the samples with typical dendritic microstructure and higher chromium content, until nickel content have not significant effect. According to this, in ternary Co-Cr-Ni phase diagram was located the small concentration region (about samples 5 and 9) in them alloy properties can satisfied the high requirements for biomedical applications. This region is considerably larger in Co-Cr-Mo phase diagram

  11. STUDY OF MICROSTRUCTURE, HARDNESS AND WEAR PROPERTIES OF SAND CAST Cu-4Ni-6Sn BRONZE ALLOY

    Directory of Open Access Journals (Sweden)

    S. ILANGOVAN

    2015-04-01

    Full Text Available An alloy of Cu-4Ni-6Sn was cast in the sand moulds. The cast rods were homogenized, solution heat treated and aged for different periods of time. The specimens were prepared from the rods to study the microstructure, microhardness and wear properties. It was found that the aging process increases the hardness of the alloy significantly. It was due to the change in the microstructure of the alloy. Further, spinodal decomposition and the ordering reaction take place during the aging treatment. Specific wear rate was found to decrease with the hardness of the alloy. Coefficient of friction remains constant and is not affected by the aging process.

  12. Microstructure and mechanical properties of electron beam welded dissimilar steel to Fe–Al alloy joints

    Energy Technology Data Exchange (ETDEWEB)

    Dinda, Soumitra Kumar; Basiruddin Sk, Md.; Roy, Gour Gopal [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur (India); Srirangam, Prakash, E-mail: p.srirangam@warwick.ac.uk [Warwick Manufacturing Group (WMG), University of Warwick, Coventry CV4 7AL (United Kingdom)

    2016-11-20

    Electron beam welding (EBW) technique was used to perform dissimilar joining of plain carbon steel to Fe–7%Al alloy under three different weld conditions such as with beam oscillation, without beam oscillation and at higher welding speed. The effect of weld parameters on the microstructure and mechanical properties of dissimilar joints was studied using optical microscopy, SEM, EBSD, hardness, tensile and erichsen cup tests. Microstructure results show that the application of beam oscillation resulted in uniform and homogeneous microstructure compared to without beam oscillations and higher welding speed. Further, it was observed that weld microstructure changes from equiaxed to columnar grains depending on the weld speed. High weld speed results in columnar grain structure in the weld joint. Erichsen cup test results show that the application of beam oscillation results in excellent formability as compared to high weld speed. Tensile test results show no significant difference in strength properties in all three weld conditions, but the ductility was found to be highest for joints obtained with the application of weld beam oscillation as compared to without beam oscillation and high weld speed. This study shows that the application of beam oscillations plays an important role in improving the weld quality and performance of EBW dissimilar steel to Fe–Al joints.

  13. Microstructure and grain refining performance of melt-spun Al-5Ti-1B master alloy

    International Nuclear Information System (INIS)

    Zhang Zhonghua; Bian Xiufang; Wang Yan; Liu Xiangfa

    2003-01-01

    In the present work, the microstructure and grain refining performance of the melt-spun Al-5Ti-1B (wt%) master alloy have been investigated, using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and grain refining tests. It has been found that the microstructure of the melt-spun Al-5Ti-1B master alloy is mainly composed of two phases: metastable, supersaturated α-Al solid solution and uniformly dispersed TiB 2 particles, quite different from that of the rod-like alloy consisting of three phases: α-Al, blocky TiAl 3 , and clusters of TiB 2 particles. Quenching temperatures and wheel speeds (cooling rates), however, have no obvious effect on the microstructure of the melt-spun Al-5Ti-1B alloy. Grain refining tests show that rapid solidification has a significant effect on the grain refining performance of Al-5Ti-1B alloy and leads to the great increase of nucleation rate of the alloy. Nevertheless, the melt-spun Al-5Ti-1B master alloy prepared at different wheel speeds and quenching temperatures possesses the similar grain refining performance. The reasons for the microstructure formation and the improvement of the grain refining performance of the melt-spun Al-5Ti-1B master alloy have been also discussed

  14. Dielectric Characteristics of Microstructural Changes and Property Evolution in Engineered Materials

    Science.gov (United States)

    Clifford, Jallisa Janet

    Heterogeneous materials are increasingly used in a wide range of applications such as aerospace, civil infrastructure, fuel cells and many others. The ability to take properties from two or more materials to create a material with properties engineered to needs is always very attractive. Hence heterogeneous materials are evolving into more complex formulations in multiple disciplines. Design of microstructure at multiple scales control the global functional properties of these materials and their structures. However, local microstructural changes do not directly cause a proportional change to the global properties (such as strength and stiffness). Instead, local changes follow an evolution process including significant interactions. Therefore, in order to understand property evolution of engineered materials, microstructural changes need to be effectively captured. Characterizing these changes and representing them by material variables will enable us to further improve our material level understanding. In this work, we will demonstrate how microstructural features of heterogeneous materials can be described quantitatively using broadband dielectric spectroscopy (BbDS). The frequency dependent dielectric properties can capture the change in material microstructure and represent these changes in terms of material variables, such as complex permittivity. These changes in terms of material properties can then be linked to a number of different conditions, such as increasing damage due to impact or fatigue. Two different broadband dielectric spectroscopy scanning modes are presented: bulk measurements and continuous scanning to measure dielectric property change as a function of position across the specimen. In this study, we will focus on ceramic materials and fiber reinforced polymer matrix composites as test bed material systems. In the first part of the thesis, we will present how different micro-structural design of porous ceramic materials can be captured

  15. Different continuous cropping spans significantly affect microbial community membership and structure in a vanilla-grown soil as revealed by deep pyrosequencing.

    Science.gov (United States)

    Xiong, Wu; Zhao, Qingyun; Zhao, Jun; Xun, Weibing; Li, Rong; Zhang, Ruifu; Wu, Huasong; Shen, Qirong

    2015-07-01

    In the present study, soil bacterial and fungal communities across vanilla continuous cropping time-series fields were assessed through deep pyrosequencing of 16S ribosomal RNA (rRNA) genes and internal transcribed spacer (ITS) regions. The results demonstrated that the long-term monoculture of vanilla significantly altered soil microbial communities. Soil fungal diversity index increased with consecutive cropping years, whereas soil bacterial diversity was relatively stable. Bray-Curtis dissimilarity cluster and UniFrac-weighted principal coordinate analysis (PCoA) revealed that monoculture time was the major determinant for fungal community structure, but not for bacterial community structure. The relative abundances (RAs) of the Firmicutes, Actinobacteria, Bacteroidetes, and Basidiomycota phyla were depleted along the years of vanilla monoculture. Pearson correlations at the phyla level demonstrated that Actinobacteria, Armatimonadetes, Bacteroidetes, Verrucomicrobia, and Firmicutes had significant negative correlations with vanilla disease index (DI), while no significant correlation for fungal phyla was observed. In addition, the amount of the pathogen Fusarium oxysporum accumulated with increasing years and was significantly positively correlated with vanilla DI. By contrast, the abundance of beneficial bacteria, including Bradyrhizobium and Bacillus, significantly decreased over time. In sum, soil weakness and vanilla stem wilt disease after long-term continuous cropping can be attributed to the alteration of the soil microbial community membership and structure, i.e., the reduction of the beneficial microbes and the accumulation of the fungal pathogen.

  16. Kluyveromyces marxianus and Saccharomyces boulardii Induce Distinct Levels of Dendritic Cell Cytokine Secretion and Significantly Different T Cell Responses In Vitro

    NARCIS (Netherlands)

    Smith, Ida M; Baker, Adam; Christensen, Jeffrey E; Boekhout, Teun; Frøkiær, Hanne; Arneborg, Nils; Jespersen, Lene

    2016-01-01

    Interactions between members of the intestinal microbiota and the mucosal immune system can significantly impact human health, and in this context, fungi and food-related yeasts are known to influence intestinal inflammation through direct interactions with specialized immune cells in vivo. The aim

  17. The differences in esophageal motility and its clinical significance between the patients with typical and atypical symptoms of non-erosive reflux disease

    Directory of Open Access Journals (Sweden)

    Ling LIN

    2016-01-01

    Full Text Available Objective  To study the characteristics of esophageal motility in the patients with different symptoms of nonerosive reflux disease (non-erosive reflux disease, NERD. Methods  Eighty-six patients with NERD who visited the Department of Gastroenterology in our hospital from August 2012 to December 2014 were selected. They were all evaluated with upper gastrointestinal endoscopy and high resolution esophageal manometry. Those who had neither definite esophageal mucosal erosion nor Barrett's esophagus at endoscopy were diagnosed as NERD. According to the presence or absence of typical acid reflux and/or heartburn symptoms, patients with NERD were divided into two groups: the typical symptom group (47 cases, and the atypical symptom group (39 cases. High resolution measurement of esophageal pressure was used to evaluate the differences in esophageal dynamic characteristics between patients with different symptoms of NERD. The final results were analyzed with t test and chi-square test. Results  Compared with atypical symptom group, both the resting pressure (20.68±1.64mmHg vs 15.79±1.21mmHg respectively, P0.05. Conclusion  There is a difference in esophageal motility characteristics between the patients with typical and atypical symptoms of NERD, and the main differences are changes in the resting pressure and residual pressure of LES. DOI: 10.11855/j.issn.0577-7402.2015.12.12

  18. The temperature-dependent microstructure of PEDOT/PSS films: insights from morphological, mechanical and electrical analyses

    KAUST Repository

    Zhou, Jian; Anjum, Dalaver H.; Chen, Long; Xu, Xuezhu; Ventura, Isaac Aguilar; Jiang, Long; Lubineau, Gilles

    2014-01-01

    microstructure changes at different temperatures and correlates the microstructure with its physical properties (mechanical and electrical). We used High-Angle Annular Dark-Field Scanning Electron Microscopy (HAADF-STEM) combined with electron energy loss

  19. Effect of microstructure on the impact toughness of high strength steels

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, I.

    2014-07-01

    One of the major challenges in the development of new steel grades is to get increasingly high strength combined with a low ductile brittle transition temperature and a high upper shelf energy. This requires the appropriate microstructural design. Toughness in steels is controlled by different microstructural constituents. Some of them, like inclusions, are intrinsic while others happening at different microstructural scales relate to processing conditions. A series of empirical equations express the transition temperature as a sum of contributions from substitutional solutes, free nitrogen, carbides, pearlite, grain size and eventually precipitation strengthening. Aimed at developing a methodology that could be applied to high strength steels, microstructures with a selected degree of complexity were produced at laboratory in a Nb-microalloyed steel. As a result a model has been developed that consistently predicts the Charpy curves for ferrite-pearlite, bainitic and quenched and tempered microstructures using as input data microstructural parameters. This model becomes a good tool for microstructural design. (Author)

  20. Microstructure and fractal characteristics of the solid-liquid interface forming during directional solidification of Inconel 718

    Directory of Open Access Journals (Sweden)

    WANG Ling

    2007-08-01

    Full Text Available The solidification microstructure and fractal characteristics of the solid-liquid interfaces of Inconel 718, under different cooling rates during directional solidification, were investigated by using SEM. Results showed that 5 μm/s was the cellular-dendrite transient rate. The prime dendrite arm spacing (PDAS was measured by Image Tool and it decreased with the cooling rate increased. The fractal dimension of the interfaces was calculated and it changes from 1.204310 to 1.517265 with the withdrawal rate ranging from 10 to 100 μm/s. The physical significance of the fractal dimension was analyzed by using fractal theory. It was found that the fractal dimension of the dendrites can be used to describe the solidification microstructure and parameters at low cooling rate, but both the fractal dimension and the dendrite arm spacing are needed in order to integrally describe the evaluation of the solidification microstructure completely.

  1. Behavior of porous beryllium under thermomechanical loading. Part 6. Effect of pressure on the microstructure of plasma-sprayed beryllium

    International Nuclear Information System (INIS)

    Hanafee, J.E.; Snell, E.O.

    1975-01-01

    The effects of pressure and specimen preparation on the microstructure of two grades of porous plasma-sprayed beryllium were determined. One grade, P-1, was sintered after spraying while the other grade, P-10, was tested in the as-sprayed condition. the principal microstructural characteristics studied were grain size: grain morphology, and void distribution and size. It was found that machining can readily cause a significant dense surface layer on the porous beryllium specimens, and that the dense surface layer can be removed by etching. There was substantial difference in microstructure between the P-1 sintered and P-10 unsintered specimens both before and after being subjected to shock waves and static compression. (U.S.)

  2. Microstructural evolution in inhomogeneous elastic media

    International Nuclear Information System (INIS)

    Jou, H.J.; Leo, P.H.; Lowengrub, J.S.

    1997-01-01

    We simulate the diffusional evolution of microstructures produced by solid state diffusional transformations in elastically stressed binary alloys in two dimensions. The microstructure consists of arbitrarily shaped precipitates embedded coherently in an infinite matrix. The precipitate and matrix are taken to be elastically isotropic, although they may have different elastic constants (elastically inhomogeneous). Both far-field applied strains and mismatch strains between the phases are considered. The diffusion and elastic fields are calculated using the boundary integral method, together with a small scale preconditioner to remove ill-conditioning. The precipitate-matrix interfaces are tracked using a nonstiff time updating method. The numerical method is spectrally accurate and efficient. Simulations of a single precipitate indicate that precipitate shapes depend strongly on the mass flux into the system as well as on the elastic fields. Growing shapes (positive mass flux) are dendritic while equilibrium shapes (zero mass flux) are squarish. Simulations of multiparticle systems show complicated interactions between precipitate morphology and the overall development of microstructure (i.e., precipitate alignment, translation, merging, and coarsening). In both single and multiple particle simulations, the details of the microstructural evolution depend strongly o the elastic inhomogeneity, misfit strain, and applied fields. 57 refs., 24 figs

  3. VLSI electronics microstructure science

    CERN Document Server

    1982-01-01

    VLSI Electronics: Microstructure Science, Volume 4 reviews trends for the future of very large scale integration (VLSI) electronics and the scientific base that supports its development.This book discusses the silicon-on-insulator for VLSI and VHSIC, X-ray lithography, and transient response of electron transport in GaAs using the Monte Carlo method. The technology and manufacturing of high-density magnetic-bubble memories, metallic superlattices, challenge of education for VLSI, and impact of VLSI on medical signal processing are also elaborated. This text likewise covers the impact of VLSI t

  4. VLSI electronics microstructure science

    CERN Document Server

    1981-01-01

    VLSI Electronics: Microstructure Science, Volume 3 evaluates trends for the future of very large scale integration (VLSI) electronics and the scientific base that supports its development.This book discusses the impact of VLSI on computer architectures; VLSI design and design aid requirements; and design, fabrication, and performance of CCD imagers. The approaches, potential, and progress of ultra-high-speed GaAs VLSI; computer modeling of MOSFETs; and numerical physics of micron-length and submicron-length semiconductor devices are also elaborated. This text likewise covers the optical linewi

  5. CXCR4 expression varies significantly among different subtypes of glioblastoma multiforme (GBM) and its low expression or hypermethylation might predict favorable overall survival.

    Science.gov (United States)

    Ma, Xinlong; Shang, Feng; Zhu, Weidong; Lin, Qingtang

    2017-09-01

    CXCR4 is an oncogene in glioblastoma multiforme (GBM) but the mechanism of its dysregulation and its prognostic value in GBM have not been fully understood. Bioinformatic analysis was performed by using R2 and the UCSC Xena browser based on data from GSE16011 in GEO datasets and in GBM cohort in TCGA database (TCGA-GBM). Kaplan Meier curves of overall survival (OS) were generated to assess the association between CXCR4 expression/methylation and OS in patients with GBM. GBM patients with high CXCR4 expression had significantly worse 5 and 10 yrs OS (p GBM subtypes, there was an inverse relationship between overall DNA methylation and CXCR4 expression. CXCR4 expression was significantly lower in CpG island methylation phenotype (CIMP) group than in non CIMP group. Log rank test results showed that patients with high CXCR4 methylation (first tertile) had significantly better 5 yrs OS (p = 0.038). CXCR4 expression is regulated by DNA methylation in GBM and its low expression or hypermethylation might indicate favorable OS in GBM patients.

  6. The effect of heat treatments applied to superstructure porcelain on the mechanical properties and microstructure of lithium disilicate glass ceramics.

    Science.gov (United States)

    Özdemir, Hatice; Özdoğan, Alper

    2018-01-30

    The aim of this study was to investigate that heat treatments with different numbers applied to superstructure porcelain whether effects microstructure and mechanical properties of lithium disilicate ceramic (LDC). Eighty disc-shaped specimens were fabricated from IPS e.max Press. Specimens were fired at heating values of porcelain in different numbers and divided four groups (n=5). Initial Vickers hardness were measured and X-ray diffraction (XRD) analysis was performed. Different surface treatment were applied and then Vickers hardness, surface roughness and environmental scanning electron microscopy (ESEM) analysis were performed. Data were analyzed with Varyans analysis and Tukey HSD test (α=0.05). Initial hardness among groups was no significant different (p>0.05), but hardness and surface roughness after surface treatments were significant different (pmicrostructure of LDC. Increasing firing numbers and surface treatments effect the microstructure of LDC.

  7. Celebrating diversity: the significance of cultural differences on reading comprehension processes of the young adult EFL learner in a matriculation preparation programme in Israel

    OpenAIRE

    Hellerstein-Yehezkel, Devora

    2013-01-01

    Reading comprehension in English as a foreign language (EFL) is a key to success in academic studies in Israel. As Israel is a cultural melting pot, adult students come from widely diverse educational backgrounds, often determined by their cultural environment. They arrive at the university or college classroom with vastly different approaches to learning and reading, in general, and to reading in EFL, in particular. The challenge for the EFL teacher is to help students draw from their cultur...

  8. Biological significance of [14C]phenol accumulation in different organs of a murrel, Channa punctatus, and the common carp, Cyprinus carpio

    International Nuclear Information System (INIS)

    Mukherjee, D.; Bhattacharya, S.; Kumar, V.; Moitra, J.

    1990-01-01

    Phenol, a ubiquitous component of industrial effluents, is a common pollutant of water resources and a serious threat to fish. The present work demonstrates that a significant amount of phenol is retained by various tissues of the common carp, Cyprinus carpio, and the snake-headed murrel, Channa punctatus. The rate of [ 14 C]phenol accumulation was higher carp than in the murrel. It is suggested that retention of phenol in the brain and ovary may seriously affect the reproductive potential of the fish

  9. Effect of cooling rate on the microstructure and mechanical properties of Nb-microalloyed steels

    International Nuclear Information System (INIS)

    Shanmugam, S.; Ramisetti, N.K.; Misra, R.D.K.; Mannering, T.; Panda, D.; Jansto, S.

    2007-01-01

    We describe here the effect of cooling rate on the microstructure and mechanical properties of Nb-microalloyed steels that were processed as structural beams at three different cooling rates. Nb-microalloyed steels exhibited increase in yield strength with increase in cooling rate during processing. However, the increase in the yield strength was not accompanied by loss in toughness. The microstructure at conventional cooling rate, primarily consisted of polygonal ferrite-pearlite microconstituents, while at intermediate cooling rate besides polygonal ferrite and pearlite contained significant fraction of degenerated pearlite and lath-type ferrite. At higher cooling rate, predominantly, lath-type (acicular) or bainitic ferrite was obtained. The precipitation characteristics were similar at the three cooling rates investigated with precipitation occurring at grain boundaries, on dislocations, and in the ferrite matrix. The fine scale (∼8-12 nm) precipitates in the ferrite matrix were MC type of niobium carbides. The microstructural studies suggest that the increase in toughness of Nb-microalloyed steels with increase in cooling rate is related to the change in the microstructure from predominantly ferrite-pearlite to predominantly bainitic ferrite

  10. Effect of cooling rate on the microstructure and mechanical properties of Nb-microalloyed steels

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, S. [Center for Structural and Functional Materials, University of Louisiana at Lafayette, Lafayette, LA 70504-4130 (United States); Ramisetti, N.K. [Department of Chemical Engineering, University of Louisiana at Lafayette, Lafayette, LA 70504-4130 (United States); Misra, R.D.K. [Center for Structural and Functional Materials, University of Louisiana at Lafayette, Lafayette, LA 70504-4130 (United States); Department of Chemical Engineering, University of Louisiana at Lafayette, Lafayette, LA 70504-4130 (United States)], E-mail: dmisra@louisiana.edu; Mannering, T. [Nucor-Yamato Steel, P.O. Box 1228, 5929 East State Highway 18, Blytheville, AR 72316 (United States); Panda, D. [Nucor-Yamato Steel, P.O. Box 1228, 5929 East State Highway 18, Blytheville, AR 72316 (United States); Jansto, S. [Reference Metals, 1000 Old Pond Road, Bridgeville, PA 15017 (United States)

    2007-07-15

    We describe here the effect of cooling rate on the microstructure and mechanical properties of Nb-microalloyed steels that were processed as structural beams at three different cooling rates. Nb-microalloyed steels exhibited increase in yield strength with increase in cooling rate during processing. However, the increase in the yield strength was not accompanied by loss in toughness. The microstructure at conventional cooling rate, primarily consisted of polygonal ferrite-pearlite microconstituents, while at intermediate cooling rate besides polygonal ferrite and pearlite contained significant fraction of degenerated pearlite and lath-type ferrite. At higher cooling rate, predominantly, lath-type (acicular) or bainitic ferrite was obtained. The precipitation characteristics were similar at the three cooling rates investigated with precipitation occurring at grain boundaries, on dislocations, and in the ferrite matrix. The fine scale ({approx}8-12 nm) precipitates in the ferrite matrix were MC type of niobium carbides. The microstructural studies suggest that the increase in toughness of Nb-microalloyed steels with increase in cooling rate is related to the change in the microstructure from predominantly ferrite-pearlite to predominantly bainitic ferrite.

  11. Direct Numerical Simulations of Microstructure Effects During High-Rate Loading of Additively Manufactured Metals

    Science.gov (United States)

    Battaile, Corbett; Owen, Steven; Moore, Nathan

    2017-06-01

    The properties of most engineering materials depend on the characteristics of internal microstructures and defects. In additively manufactured (AM) metals, these can include polycrystalline grains, impurities, phases, and significant porosity that qualitatively differ from conventional engineering materials. The microscopic details of the interactions between these internal defects, and the propagation of applied loads through the body, act in concert to dictate macro-observable properties like strength and compressibility. In this work, we used Sandia's ALEGRA finite element software to simulate the high-strain-rate loading of AM metals from laser engineered net shaping (LENS) and thermal spraying. The microstructural details of the material were represented explicitly, such that internal features like second phases and pores are captured and meshed as individual entities in the computational domain. We will discuss the dependence of the high-strain-rate mechanical properties on microstructural characteristics such as the shapes, sizes, and volume fractions of second phases and pores. In addition, we will examine how the details of the microstructural representation affect the microscopic material response to dynamic loads, and the effects of using ``stair-step'' versus conformal interfaces smoothed via the SCULPT tool in Sandia's CUBIT software. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the US DOE NNSA under contract DE-AC04-94AL85000.

  12. Mechanical Properties and Microstructural Characterization of Aged Nickel-based Alloy 625 Weld Metal

    Science.gov (United States)

    Silva, Cleiton Carvalho; de Albuquerque, Victor Hugo C.; Miná, Emerson Mendonça; Moura, Elineudo P.; Tavares, João Manuel R. S.

    2018-03-01

    The aim of this work was to evaluate the different phases formed during solidification and after thermal aging of the as-welded 625 nickel-based alloy, as well as the influence of microstructural changes on the mechanical properties. The experiments addressed aging temperatures of 650 and 950 °C for 10, 100, and 200 hours. The samples were analyzed by electron microscopy, microanalysis, and X-ray diffraction in order to identify the secondary phases. Mechanical tests such as hardness, microhardness, and Charpy-V impact test were performed. Nondestructive ultrasonic inspection was also conducted to correlate the acquired signals with mechanical and microstructural properties. The results show that the alloy under study experienced microstructural changes when aged at 650 °C. The aging was responsible by the dissolution of the Laves phase formed during the solidification and the appearance of γ″ phase within interdendritic region and fine carbides along the solidification grain boundaries. However, when it was aged at 950 °C, the Laves phase was continuously dissolved and the excess Nb caused the precipitation of the δ-phase (Ni3Nb), which was intensified at 10 hours of aging, with subsequent dissolution for longer periods such as 200 hours. Even when subjected to significant microstructural changes, the mechanical properties, especially toughness, were not sensitive to the dissolution and/or precipitation of the secondary phases.

  13. The effect of strain distribution on microstructural developments during forging in a newly developed nickel base superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Buckingham, R.C. [Institute of Structural Materials, Swansea University, Bay Campus, Fabian Way, Swansea SA1 8EN (United Kingdom); Argyrakis, C.; Hardy, M.C. [Rolls-Royce plc, PO Box 31, Derby DE24 8BJ (United Kingdom); Birosca, S., E-mail: 522042@swansea.ac.uk [Institute of Structural Materials, Swansea University, Bay Campus, Fabian Way, Swansea SA1 8EN (United Kingdom)

    2016-01-27

    In the current study, the effect of strain distribution in a simple forging geometry on the propensity for recrystallization, and its impact on mechanical properties has been investigated in a newly developed experimental nickel-based superalloy. The new alloy was produced via a Powder Metallurgy (PM) route and was subsequently Hot Isostatic Processed (HIP), isothermally forged, and heat treated to produce a coarse grain microstructure with average grain size of 23–32 μm. The alloy was examined by means of Electron Back-Scatter Diffraction (EBSD) to characterise the microstructural features such as grain orientation and morphology, grain boundary characteristics and the identification of potential Prior Particle Boundaries (PPBs) throughout each stage of the processing route. Results at the central region of the cross-section plane parallel to the loading direction showed significant microstructural differences across the forging depth. This microstructural variation was found to be highly dependent on the value of local strain imparted during forging such that areas of low effective strain showed partial recrystallisation and a necklace grain structure was observed following heat treatment. Meanwhile, a fully recrystallised microstructure with no PPBs was observed in the areas of high strain values, in the central region of the forging.

  14. Quantifying the effect of microstructure variability on the yield strength predictions of Ni-base superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Tiley, J.S. [Air Force Research Laboratory, Wright Patterson AFB, OH 45433 (United States); Kim, S.L.; Parthasarathy, T.A. [UES, Inc., Wright Patterson AFB, OH 45433 (United States); Loughnane, G.T. [Wright State University, Dayton, OH 45435 (United States); Kublik, R.; Salem, A.A. [Materials Resources LLC, Dayton, OH 45402 (United States)

    2017-02-08

    Physics-based models for predicting the mechanical behavior of Ni-based superalloys as a function of microstructure features require the use of microstructure data for calibration and verification. Accurate representation of the heterogeneity of microstructure features requires accurate selection of the representative microstructure data size (i.e. image size). Thus, this work is carried out to address the influence of microstructure data size on the accuracy of a discrete dislocation dynamic model in predicting the critical resolved share stress (CRSS) of IN100. Microstructure features from backscattered electron images were extracted using image processing techniques. Single point statistics (e.g. area fraction, precipitate size, and distance between γ' particles) and higher order statistics using two-point correlations were calculated from segmented 2-D images. Modified Bhattacharyya Coefficient analysis techniques were employed to calculate three-dimensional particle size distributions. Results indicate a significant influence of the microstructure data size on the calculated CRSS.

  15. Microstructured hollow fibers for ultrafiltration

    NARCIS (Netherlands)

    Culfaz, Pmar Zeynep; Culfaz, P.Z.; Rolevink, Hendrikus H.M.; van Rijn, C.J.M.; Lammertink, Rob G.H.; Wessling, Matthias

    2010-01-01

    Hollow fiber ultrafiltration membranes with a corrugated outer microstructure were prepared from a PES/PVP blend. The effect of spinning parameters such as air gap, take-up speed, polymer dope viscosity and coagulation value on the microstructure and membrane characteristics was investigated. Fibers

  16. Difference in prognostic significance of maximum standardized uptake value on [18F]-fluoro-2-deoxyglucose positron emission tomography between adenocarcinoma and squamous cell carcinoma of the lung

    International Nuclear Information System (INIS)

    Tsutani, Yasuhiro; Miyata, Yoshihiro; Misumi, Keizo; Ikeda, Takuhiro; Mimura, Takeshi; Hihara, Jun; Okada, Morihito

    2011-01-01

    This study evaluates the prognostic significance of [18F]-fluoro-2-deoxyglucose positron emission tomography/computed tomography findings according to histological subtypes in patients with completely resected non-small cell lung cancer. We examined 176 consecutive patients who had undergone preoperative [18F]-fluoro-2-deoxyglucose-positron emission tomography/computed tomography imaging and curative surgical resection for adenocarcinoma (n=132) or squamous cell carcinoma (n=44). Maximum standardized uptake values for the primary lesions in all patients were calculated as the [18F]-fluoro-2-deoxyglucose uptake and the surgical results were analyzed. The median values of maximum standardized uptake value for the primary tumors were 2.60 in patients with adenocarcinoma and 6.95 in patients with squamous cell carcinoma (P 6.95 (P=0.83) among patients with squamous cell carcinoma, 2-year disease-free survival rates were 93.9% for maximum standardized uptake value ≤3.7 and 52.4% for maximum standardized uptake value >3.7 (P<0.0001) among those with adenocarcinoma, and notably, 100 and 57.2%, respectively, in patients with Stage I adenocarcinoma (P<0.0001). On the basis of the multivariate Cox analyses of patients with adenocarcinoma, maximum standardized uptake value (P=0.008) was a significantly independent factor for disease-free survival as well as nodal metastasis (P=0.001). Maximum standardized uptake value of the primary tumor was a powerful prognostic determinant for patients with adenocarcinoma, but not with squamous cell carcinoma of the lung. (author)

  17. The significance of a uniform definition of pathological lymph nodes in Hodgkin lymphoma: Impact of different thresholds for positive lymph nodes in CT imaging on staging and therapy

    International Nuclear Information System (INIS)

    Vorwerk, Hilke; Obenauer, Silvia; Schmidberger, Heinz; Hess, Clemens F.; Weiss, Elisabeth

    2008-01-01

    Background and Purpose: The most commonly used approach for the assessment for differentiating malignant versus reactive lymph nodes is the measurement of the cross-section diameter of the lymph nodes in the transversal CT-planes. The intention of this article is to assess the impact of varying definitions of pathological lymph node size in CT-imaging in patients with Hodgkin lymphoma and to evaluate its effect on staging, chemotherapy regimes and radiation field size. Materials and methods: Pretherapeutic CT-scans of 10 consecutive patients with Hodgkin lymphoma have been evaluated based on two different definitions for malignant lymph node size; the classification of the German study group for Hodgkin lymphoma (1.0 cm) and the classification according to the results of the Cotswold consensus meeting 1989 (1.5 cm). Results: Applying the definitions of the DHSG and the Cotswold meeting we found more affected lymph node regions compared to the evaluation of the referring institutions in 9/10 and 6/10 patients, higher stages in 2/10 and 1/10 patients, more intense chemotherapy regimes in 3/10 and 1/10 and larger radiation fields in 10/10 and 6/10 patients, respectively. Conclusions: Varying definitions of pathologic lymph node size and inconsequent application of definitions reduce the comparability between different studies and within each study

  18. Application of High-Density Electropulsing to Improve the Performance of Metallic Materials: Mechanisms, Microstructure and Properties

    Directory of Open Access Journals (Sweden)

    Yinying Sheng

    2018-01-01

    Full Text Available The technology of high-density electropulsing has been applied to increase the performance of metallic materials since the 1990s and has shown significant advantages over traditional heat treatment in many aspects. However, the microstructure changes in electropulsing treatment (EPT metals and alloys have not been fully explored, and the effects vary significantly on different material. When high-density electrical pulses are applied to metals and alloys, the input of electric energy and thermal energy generally leads to structural rearrangements, such as dynamic recrystallization, dislocation movements and grain refinement. The enhanced mechanical properties of the metals and alloys after high-density electropulsing treatment are reflected by the significant improvement of elongation. As a result, this technology holds great promise in improving the deformation limit and repairing cracks and defects in the plastic processing of metals. This review summarizes the effect of high-density electropulsing treatment on microstructural properties and, thus, the enhancement in mechanical strength, hardness and corrosion performance of metallic materials. It is noteworthy that the change of some properties can be related to the structure state before EPT (quenched, annealed, deformed or others. The mechanisms for the microstructural evolution, grain refinement and formation of oriented microstructures of different metals and alloys are presented. Future research trends of high-density electrical pulse technology for specific metals and alloys are highlighted.

  19. Application of High-Density Electropulsing to Improve the Performance of Metallic Materials: Mechanisms, Microstructure and Properties.

    Science.gov (United States)

    Sheng, Yinying; Hua, Youlu; Wang, Xiaojian; Zhao, Xueyang; Chen, Lianxi; Zhou, Hanyu; Wang, James; Berndt, Christopher C; Li, Wei

    2018-01-24

    The technology of high-density electropulsing has been applied to increase the performance of metallic materials since the 1990s and has shown significant advantages over traditional heat treatment in many aspects. However, the microstructure changes in electropulsing treatment (EPT) metals and alloys have not been fully explored, and the effects vary significantly on different material. When high-density electrical pulses are applied to metals and alloys, the input of electric energy and thermal energy generally leads to structural rearrangements, such as dynamic recrystallization, dislocation movements and grain refinement. The enhanced mechanical properties of the metals and alloys after high-density electropulsing treatment are reflected by the significant improvement of elongation. As a result, this technology holds great promise in improving the deformation limit and repairing cracks and defects in the plastic processing of metals. This review summarizes the effect of high-density electropulsing treatment on microstructural properties and, thus, the enhancement in mechanical strength, hardness and corrosion performance of metallic materials. It is noteworthy that the change of some properties can be related to the structure state before EPT (quenched, annealed, deformed or others). The mechanisms for the microstructural evolution, grain refinement and formation of oriented microstructures of different metals and alloys are presented. Future research trends of high-density electrical pulse technology for specific metals and alloys are highlighted.

  20. Application of High-Density Electropulsing to Improve the Performance of Metallic Materials: Mechanisms, Microstructure and Properties

    Science.gov (United States)

    Sheng, Yinying; Hua, Youlu; Zhao, Xueyang; Chen, Lianxi; Zhou, Hanyu; Wang, James; Berndt, Christopher C.; Li, Wei

    2018-01-01

    The technology of high-density electropulsing has been applied to increase the performance of metallic materials since the 1990s and has shown significant advantages over traditional heat treatment in many aspects. However, the microstructure changes in electropulsing treatment (EPT) metals and alloys have not been fully explored, and the effects vary significantly on different material. When high-density electrical pulses are applied to metals and alloys, the input of electric energy and thermal energy generally leads to structural rearrangements, such as dynamic recrystallization, dislocation movements and grain refinement. The enhanced mechanical properties of the metals and alloys after high-density electropulsing treatment are reflected by the significant improvement of elongation. As a result, this technology holds great promise in improving the deformation limit and repairing cracks and defects in the plastic processing of metals. This review summarizes the effect of high-density electropulsing treatment on microstructural properties and, thus, the enhancement in mechanical strength, hardness and corrosion performance of metallic materials. It is noteworthy that the change of some properties can be related to the structure state before EPT (quenched, annealed, deformed or others). The mechanisms for the microstructural evolution, grain refinement and formation of oriented microstructures of different metals and alloys are presented. Future research trends of high-density electrical pulse technology for specific metals and alloys are highlighted. PMID:29364844

  1. Microstructure in Zircaloy Creep Tested in the R2 Reactor

    International Nuclear Information System (INIS)

    Pettersson, Kjell

    2004-12-01

    Tubular specimens of Zircaloy-4 have been creep tested in bending in the R2 reactor in Studsvik. The creep deformation in the reactor core is accelerated in comparison with creep deformation outside the reactor core. The possible mechanisms behind this behaviour are described briefly. In order to determine which the actual mechanism is, the microstructure of the material creep tested in the R2 reactor has been examined by transmission electron microscopy. Due to the bending, material subjected to both tensile and compressive stress during creep was available. Since some of the proposed mechanisms might give microstructures which are different when the material is subjected to compressive or tensile stress it was assumed that examination of both types of material would give valuable information with regard to the operating mechanism. The result of the examination was that in the as-irradiated condition there were no obvious differences detected between materials which had been deformed in tension or compression. After a heat treatment to coarsen the irradiation induced microstructure there were still no significant differences between the two types of material. However it was now observed that in addition to dislocation loops the microstructure also contained network dislocations which presumably had been invisible in the electron microscope before heat treatment due to the high density of small dislocation loops in this state. It is therefore concluded that the most probable mechanism for irradiation creep in this case is climb and glide of the network dislocations. The role of irradiation is two-fold: It accelerates climb due to the production of point defects of which more interstitials than vacancies arrive to the network dislocations stopped at an obstacles. This leads to a net climb after which a dislocation is released from the obstacle and an amount of glide takes place. The second effect is the production of loops which serve as an increasing density of

  2. Short separation regression improves statistical significance and better localizes the hemodynamic response obtained by near-infrared spectroscopy for tasks with differing autonomic responses.

    Science.gov (United States)

    Yücel, Meryem A; Selb, Juliette; Aasted, Christopher M; Petkov, Mike P; Becerra, Lino; Borsook, David; Boas, David A

    2015-07-01

    Autonomic nervous system response is known to be highly task-dependent. The sensitivity of near-infrared spectroscopy (NIRS) measurements to superficial layers, particularly to the scalp, makes it highly susceptible to systemic physiological changes. Thus, one critical step in NIRS data processing is to remove the contribution of superficial layers to the NIRS signal and to obtain the actual brain response. This can be achieved using short separation channels that are sensitive only to the hemodynamics in the scalp. We investigated the contribution of hemodynamic fluctuations due to autonomous nervous system activation during various tasks. Our results provide clear demonstrations of the critical role of using short separation channels in NIRS measurements to disentangle differing autonomic responses from the brain activation signal of interest.

  3. Compositional Similarities and Differences between Transparent Exopolymer Particles (TEP) from two Marine Bacteria and two Marine Algae: Significance to Surface Biofouling

    KAUST Repository

    Li, Sheng; Winters, Harvey; Villacorte, L.O.; Ekowati, Y.; Emwas, Abdul-Hamid M.; Kennedy, M.D.; Amy, Gary L.

    2015-01-01

    indicated that both isolated bacterial and algal TEP/TEP precursors were associated with protein-like materials, and most TEP precursors were high-molecular-weight biopolymers. Furthermore all investigated algal and bacterial TEP/TEP precursors showed a lectin-like property, which can enable them to act as a chemical conditioning layer and to agglutinate bacteria. This property may enhance surface biofouling. However, both proton nuclear magnetic resonance (NMR) spectra and the nitrogen/carbon (N/C) ratios suggested that the algal TEP/TEP precursors contained much less protein content than the bacterial TEP/TEP precursors. This difference may influence their initial deposition and further development of surface biofouling.

  4. Advanced Steel Microstructural Classification by Deep Learning Methods.

    Science.gov (United States)

    Azimi, Seyed Majid; Britz, Dominik; Engstler, Michael; Fritz, Mario; Mücklich, Frank

    2018-02-01

    The inner structure of a material is called microstructure. It stores the genesis of a material and determines all its physical and chemical properties. While microstructural characterization is widely spread and well known, the microstructural classification is mostly done manually by human experts, which gives rise to uncertainties due to subjectivity. Since the microstructure could be a combination of different phases or constituents with complex substructures its automatic classification is very challenging and only a few prior studies exist. Prior works focused on designed and engineered features by experts and classified microstructures separately from the feature extraction step. Recently, Deep Learning methods have shown strong performance in vision applications by learning the features from data together with the classification step. In this work, we propose a Deep Learning method for microstructural classification in the examples of certain microstructural constituents of low carbon steel. This novel method employs pixel-wise segmentation via Fully Convolutional Neural Network (FCNN) accompanied by a max-voting scheme. Our system achieves 93.94% classification accuracy, drastically outperforming the state-of-the-art method of 48.89% accuracy. Beyond the strong performance of our method, this line of research offers a more robust and first of all objective way for the difficult task of steel quality appreciation.

  5. Blastocystis Isolates from Patients with Irritable Bowel Syndrome and from Asymptomatic Carriers Exhibit Similar Parasitological Loads, but Significantly Different Generation Times and Genetic Variability across Multiple Subtypes.

    Directory of Open Access Journals (Sweden)

    Gie-Bele Vargas-Sanchez

    Full Text Available Blastocystis spp is a common intestinal parasite of humans and animals that has been associated to the etiology of irritable bowel syndrome (IBS; however, some studies have not found this association. Furthermore, many biological features of Blastocystis are little known. The objective of present study was to assess the generation times of Blastocystis cultures, from IBS patients and from asymptomatic carriers. A total of 100 isolates were obtained from 50 IBS patients and from 50 asymptomatic carriers. Up to 50 mg of feces from each participant were cultured in Barret's and in Pavlova's media during 48 h. Initial and final parasitological load were measured by microscopy and by quantitative PCR. Amplicons were purified, sequenced and submitted to GenBank; sequences were analysed for genetic diversity and a Bayesian inference allowed identifying genetic subtypes (ST. Generation times for Blastocystis isolates in both media, based on microscopic measures and molecular assays, were calculated. The clinical symptoms of IBS patients and distribution of Blastocystis ST 1, 2 and 3 in both groups was comparable to previous reports. Interestingly, the group of cases showed scarce mean nucleotide diversity (π as compared to the control group (0.011±0.016 and 0.118±0.177, respectively, whilst high gene flow and small genetic differentiation indexes between different ST were found. Besides, Tajima's D test showed negative values for ST1-ST3. No statistical differences regarding parasitological load between cases and controls in both media, as searched by microscopy and by qPCR, were detected except that parasites grew faster in Barret's than in Pavlova's medium. Interestingly, slow growth of isolates recovered from cases in comparison to those of controls was observed (p<0.05. We propose that generation times of Blastocystis might be easily affected by intestinal environmental changes due to IBS probably because virulent strains with slow growth may be

  6. Avoiding delayed diagnosis of significant blunt bowel and mesenteric injuries: Can a scoring tool make the difference? A 7-year retrospective cohort study.

    Science.gov (United States)

    Zingg, Tobias; Agri, Fabio; Bourgeat, Mylène; Yersin, Bertrand; Romain, Benoît; Schmidt, Sabine; Keller, Nathalie; Demartines, Nicolas

    2018-01-01

    Significant blunt bowel and mesenteric injuries (sBBMI) are frequently missed despite the widespread use of computed tomography (CT). Early treatment improves the outcome related to these injuries. The aim of this study was to assess the prevalence of sBBMI, the incidence of delayed diagnosis and to test the performance of the Bowel Injury Prediction Score (BIPS), determined by the white blood cell (WBC) count, presence or absence of abdominal tenderness and CT grade of mesenteric injury. Single-centre, registry-based retrospective cohort study, screening all consecutive trauma patients admitted to Lausanne University Hospital Trauma Centre from 2008 to 2015 after a road traffic accident. All patients with reliable information about the presence or absence of sBBMI who underwent abdominal CT and for whom calculation of the BIPS was possible were included for analysis. The incidence of delayed (>24h after admission) diagnosis in the patient group with sBBMI was determined and the diagnostic performance of the BIPS for sBBMI was assessed. For analysis, 766 patients with reliable information about the presence or absence of sBBMI were included. The prevalence of sBBMI was 3.1% (24/766). In 24% (5/21) of stable trauma patients undergoing CT, a diagnostic delay of more than 24h occurred. Abdominal tenderness (p<0.0001) and CT grade ≥4 (p<0.0001) were associated with sBBMI, whereas CT grade 4 alone (p=0.93) and WBC count ≥17G/l (p=0.30) were not. A BIPS ≥2 had a sensitivity of 89% (95% CI, 67-99), specificity of 89% (95% CI, 86-91), positive likelihood ratio of 8 (95% CI, 6.1-10), negative likelihood ratio of 0.12 (95% CI, 0.03-0.44), positive predictive value (PPV) of 19% (95% CI, 15-24) and negative predictive value (NPV) of 99.7% (95% CI, 98.7-99.9). CT alone identified 79% (15/19) and the BIPS 89% (17/19) of patients with sBBMI (p=0.66). Diagnostic delays in patients with sBBMI are common (24%), despite the routine use of abdominal CT. Application of the BIPS

  7. Clinical Significance of Lymph Node Metastasis in the Mesentery of the Terminal Ileum in Patients With Right-sided Colon Tumors at Different Locations.

    Science.gov (United States)

    Kang, Sung Il; Kim, Duck-Woo; Shin, Eun; Kim, Myung Jo; Son, Il Tae; Oh, Heung-Kwon; Kang, Sung-Bum

    2018-06-01

    There are limited reports on peri-ileal lymph node metastasis in patients with right-sided colon cancer, and little is known about their clinical significance. This study aimed to examine the role of tumor location in the prevalence and clinical significance of peri-ileal lymph node metastasis in patients with right-sided colon cancer. This is a retrospective study from a prospective cohort database. The study was conducted at a tertiary referral hospital. Patients with right-sided colon cancer treated with radical surgery in a hospital between May 2006 and September 2016 were included. The frequency of peri-ileal lymph node metastasis in the study cohort and the role of tumor location and the clinical characteristics of patients with peri-ileal lymph node metastasis were determined. We examined 752 cases with right-sided colon cancer including 82 cecal, 554 ascending colon, and 116 hepatic flexure cancer. Twenty patients (2.7%) had peri-ileal lymph node metastasis. The incidence of metastasis to peri-ileal lymph nodes was 7.3% (6/82) in patients with cecal cancer, 2.2% (12/554) in patients with ascending colon cancer, and 1.7% (2/116) in patients with hepatic flexure cancer. Three patients had stage III cancer and 17 had stage IV. All 3 patients with positive peri-ileal lymph nodes and stage III cancer had cecal tumors. In contrast, all patients with ascending colon or hepatic flexure cancer and positive peri-ileal lymph nodes had stage IV cancer. The results were limited by the retrospective design of the study and t