WorldWideScience

Sample records for surface studies continuing

  1. Numerical Study of Thermal Boundary Layer on a Continuous Moving Surface in Power Law Fluids

    Institute of Scientific and Technical Information of China (English)

    Hao ZHANG; Xinxin ZHANG; Liancun ZHENG

    2007-01-01

    This paper investigates flow and heat transfer of power law fluids on a continuous moving surface. The temperature distribution is obtained numerically by considering the effect of the power law viscosity on thermal diffusivity and the characteristics of the flow and heat transfer are analyzed. The results show that the distribution of the thermal boundary layer depends not only on the velocity ratio parameter of the plate, but also on the power law index and Prandtl number of fluids.

  2. Study of process variables in industrial acetic fermentation by a continuous pilot fermentor and response surfaces.

    Science.gov (United States)

    Garrido-Vidal, Diego; Pizarro, Consuelo; González-Sáiz, José M

    2003-01-01

    The modeling and optimization of industrial processes requires an intensive study of the factors involved. In this work, a continuous pilot system for studying the industrial process of acetic fermentation is developed. A Doehlert design is applied to the five variables involved in the pilot process. This experimental design allows reduction of the experimental burden and the maximum amount of information to be obtained, studying the factors at different levels depending on their significance. The experimental system provides a robust measure of the specific growth rate and the rates of substrates consumption and acetic acid production, related to the flow of effluent stream evaluated in the steady state. The results demonstrate the growth-associated kinetics of substrates and product, and the yield factors are calculated with low values of variances for the coefficients, i.e., within the range 1-11%. The specific growth rate suits the quadratic model proposed. The response surfaces generated by the model are applied to explain the behavior of the bacterial growth and, therefore, the effects of the process variables studied over the acetic acid production. Very low levels of ethanol or oxygen make the acetification rate decrease, and a saturation effect with high levels of ethanol or oxygen is also deduced. The effects of the aeration rate, agitation, and overpressure suggest a kind of inhibition of the acetic acid production caused by the oxygen that has not been practically studied before. The temperature strengthens the inhibitory effect of the ethanol and the oxygen. The conclusions of this work consolidate the structure of a hybrid model for the acetic fermentation.

  3. Correlated adatom trimer on a metal surface: a continuous-time quantum Monte Carlo study.

    Science.gov (United States)

    Savkin, V V; Rubtsov, A N; Katsnelson, M I; Lichtenstein, A I

    2005-01-21

    The problem of three interacting Kondo impurities is solved within a numerically exact continuous-time quantum Monte Carlo scheme. A suppression of the Kondo resonance by interatomic exchange interactions for different cluster geometries is investigated. It is shown that a drastic difference between the Heisenberg and Ising cases appears for antiferromagnetically coupled adatoms. The effects of magnetic frustrations in the adatom trimer are investigated, and possible connections with available experimental data are discussed.

  4. Representing genetic variation as continuous surfaces: An approach for identifying spatial dependency in landscape genetic studies

    Science.gov (United States)

    Melanie A. Murphy; Jeffrey S. Evans; Samuel A. Cushman; Andrew Storfer

    2008-01-01

    Landscape genetics, an emerging field integrating landscape ecology and population genetics, has great potential to influence our understanding of habitat connectivity and distribution of organisms. Whereas typical population genetics studies summarize gene flow as pairwise measures between sampling localities, landscape characteristics that influence population...

  5. 12th International Symposium Continuous Surface Mining

    CERN Document Server

    2015-01-01

    This edited volume contains research results presented at the 12th International Symposium Continuous Surface Mining, ISCSM Aachen 2014. The target audience primarily comprises researchers in the lignite mining industry and practitioners in this field but the book may also be beneficial for graduate students.

  6. Colloids with continuously tunable surface charge.

    Science.gov (United States)

    van Ravensteijn, Bas G P; Kegel, Willem K

    2014-09-09

    In this paper, we present a robust way to tune the surface potential of polystyrene colloids without changing the pH, ionic strength, etc. The colloids are composed of a cross-linked polystyrene core and a cross-linked vinylbenzyl chloride layer. Besides the chlorine groups, the particle surface contains sulfate/sulfonate groups (arising from the polymerization initiators) that provide a negative surface potential. Performing a Menschutkin reaction on the surface chlorine groups with tertiary amines allows us to introduce quaternary, positively charged amines. The overall charge on the particles is then determined by the ratio between the sulfate/sulfonate moieties and the quaternary amines. Using this process, we were able to invert the charge in a continuous manner without losing colloidal stability upon passing the isoelectric point. The straightforward reaction mechanism together with the fact that the reaction could be quenched rapidly resulted in a colloidal system in which the ζ potential can be tuned between -80 and 45 mV. As proof of principle, the positively charged particles were used in heterocoagulation experiments with nanometer- and micrometer-sized negatively charged silica particles to create geometrically well-defined colloidal (nano) clusters.

  7. Continuous metal plasmonic frequency selective surfaces.

    Science.gov (United States)

    Zhang, Jianfa; Ou, Jun-Yu; Papasimakis, Nikitas; Chen, Yifang; Macdonald, Kevin F; Zheludev, Nikolay I

    2011-11-07

    In the microwave part of the spectrum, where losses are minimal, metal films regularly patterned (perforated) on the sub-wavelength scale achieve spectral selectivity by balancing the transmission and reflection characteristics of the surface. Here we show for optical frequencies, where joule losses are important, that periodic structuring of a metal film without violation of continuity (i.e. without perforation) is sufficient to achieve substantial modification of reflectivity. By engineering the geometry of the structure imposed on a surface one can dramatically change the perceived color of the metal without employing any form of chemical modification, thin-film coating or diffraction effects. This novel frequency selective effect is underpinned by plasmonic Joule losses in the constituent elements of the patterns (dubbed 'intaglio' and 'bas relief' metamaterials to distinguish indented and raised structures respectively) and is specific to the optical part of the spectrum. It has the advantage of maintaining the integrity of metal surfaces and is well suited to high-throughput fabrication via techniques such as nano-imprint.

  8. Conditions of G~n Continuity Between Surfaces

    Institute of Scientific and Technical Information of China (English)

    马利庄; 彭群生; 何志钧

    1994-01-01

    Geometric continuity between parametric surfaces is an important issue in CAGD.So far rest-arches have been concentrated on it for N-dimensional surfaces whose common boundary is of N-1 dimensions.No results have ever been obtained for the case where the common boundary of the two surfaces is of L dimensions,0≤L≤N,or the two adjacent surfaces are of unequal dimensions.In this paper,the conditions of high-order geometric continuity between parametric surfaces are studied for these general cases By analysing the structure of Gn transformations,general solutions as well as an iterative method for determining adjustable functions are proposed.Some equivalent conditions of Gn continuity (nth order geometric continuity) are derived with an emphasis on conditions for triangular and rectangular Bezier surfaces.Since the Gn conditions for polynomial parametric surfaces are expressed in the form of explicit relationship of control points of Bezier surfaces,they are very useful both in theory and application for

  9. Continuous biosynthesis of biodiesel from waste cooking palm oil in a packed bed reactor: optimization using response surface methodology (RSM) and mass transfer studies.

    Science.gov (United States)

    Halim, Siti Fatimah Abdul; Kamaruddin, Azlina Harun; Fernando, W J N

    2009-01-01

    This study aimed to develop an optimal continuous procedure of lipase-catalyzes transesterification of waste cooking palm oil in a packed bed reactor to investigate the possibility of large scale production further. Response surface methodology (RSM) based on central composite rotatable design (CCRD) was used to optimize the two important reaction variables packed bed height (cm) and substrate flow rate(ml/min) for the transesterification of waste cooking palm oil in a continuous packed bed reactor. The optimum condition for the transesterification of waste cooking palm oil was as follows: 10.53 cm packed bed height and 0.57 ml/min substrate flow rate. The optimum predicted fatty acid methyl ester (FAME) yield was 80.3% and the actual value was 79%. The above results shows that the RSM study based on CCRD is adaptable for FAME yield studied for the current transesterification system. The effect of mass transfer in the packed bed reactor has also been studied. Models for FAME yield have been developed for cases of reaction control and mass transfer control. The results showed very good agreement compatibility between mass transfer model and the experimental results obtained from immobilized lipase packed bed reactor operation, showing that in this case the FAME yield was mass transfer controlled.

  10. Downward continuation of aeromagnetic data to the marine surface

    Institute of Scientific and Technical Information of China (English)

    XU Shizhe; WANG Rui; ZHOU Jianxin; XIAO Pengfei; CHEN Shengchang

    2008-01-01

    The existing methods of downward continuation of potential field cannot be used to continue the aeromagnetie data to the marine surface because of the limited continuation distance.An iteration method for the downward continuation of potential field with a much larger continuation distance has been developed,which can continue the aeromagnetic data to the marine surface and get the marine-magnetic chart with the same scale as the aeromagnetic data.This downward continuation method will greatly raise the ef- ficiency of marine-magnetic investigation.The principle of the iteration method is presented.The method is demonstrated on synthetic models and real aeromagnetic data.Also,the error brought by continuation is discussed.The efficiency of the iteration method for the downward continuation of potential field is compared with the fast fourier transform (FFT) method,the former is much better than the latter.

  11. Evaluation of ground stiffness parameters using continuous surface wave geophysics

    DEFF Research Database (Denmark)

    Gordon, Anne; Foged, Niels

    2000-01-01

    -small-strain stiffness of the ground Gmax. Continuous surface wave geophysics offers a quick, non-intrusive and economical way of making such measurements. This paper reviews the continuous surface wave techniques and evaluates, in engineering terms, the applicability of the method to the site investigation industry....

  12. Evaluation of ground stiffness parameters using continuous surface wave geophysics

    DEFF Research Database (Denmark)

    Gordon, Anne; Foged, Niels

    2000-01-01

    -small-strain stiffness of the ground Gmax. Continuous surface wave geophysics offers a quick, non-intrusive and economical way of making such measurements. This paper reviews the continuous surface wave techniques and evaluates, in engineering terms, the applicability of the method to the site investigation industry....

  13. G1 Continuity Conditions of B-spline Surfaces

    Institute of Scientific and Technical Information of China (English)

    车翔玖; 梁学章

    2002-01-01

    According to the B-spline theory and Boehm algorithm,this paper presents several necessary and sufficient G1 continuity conditions betwwen two adjacent B-spline surfaces,In Order to meet the need of application,a kind of sufficient conditions of G1 continuity are developed,and a kind of sufficient conditions of G1 continuity among N(N>2) patch B-shline surfaces meeting at a common corner are given at the end.

  14. Continuity of non-uniform recursive subdivision surfaces

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Since Doo-Sabin and Catmull-Clark surfaces were proposed in 1978, eigenstructure, convergence and continuity analyses of stationary subdivision have been performed very well, but it has been very difficult to prove the convergence and continuity of non-uniform recursive subdivision surfaces (NURSSes, for short) of arbitrary topology. In fact, so far a problem whether or not there exists the limit surface as well as G1 continuity of a non-uniform Catmull-Clark subdivision has not been solved yet. Here the concept of equivalent knot spacing is introduced. A new technique for eigenanalysis, convergence and continuity analyses of non-uniform Catmull-Clark surfaces is proposed such that the convergence and G1 continuity of NURSSes at extraordinary points are proved. In addition, slightly improved rules for NURSSes are developed. This offers us one more alternative for modeling free-form surfaces of arbitrary topologies with geometric features such as cusps, sharp edges, creases and darts, while elsewhere maintaining the same order of continuity as B-spline surfaces.

  15. Continuous atmospheric 222Rn concentration measurements to study surface-air exchange at the station of Gredos and Iruelas, in Central Spain

    Science.gov (United States)

    Grossi, Claudia; Morgui, Josep Anton; Àgueda, Alba; Batet, Oscar; Curcoll, Roger; Arias, Rosa; Arnold, Delia; Ealo, Marina; Nofuentes, Manel; Occhipinti, Paola; Sánchez-Garcíaa, Laura; Vargas, Arturo; Rodó, Xavier

    2013-04-01

    The Gredos and Iruelas station (GIC3) is part of the ClimaDat IC3 network (http://climadat.es/). This station is located in the Gredos Natural Park at a latitude of 40.22° N and a longitude of -5.14° E in the Spanish central plateau. The ClimaDat network is made by 8 stations distributed around Spain and it has been developed with the aim of studying climatic processes and the responses of impacted systems, at different time and space scales. Since November 2012, measurements of CO2, CH4, and of the natural radioactive gas 222Rn are continuously performed at GIC3 station at 20 m agl and at 1100 m asl . Maximum,minimum and average values of meteorological parameters, such as ambient air humidity and temperature, wind speed and direction are also measured at GIC3 station. Particularly, the concentration series of 222Rn measured at GIC3 station are extremely useful to evaluate the exchange of this noble radioactive gas between the soil surface and the lower troposphere in this area, under different weather situations and environmental conditions. The Gredos Natural Park is located in a granitic basement and this type of soil presents a high porosity and permeability. Furthermore, granitic materials have high activity levels of 228U. These factors enable large amount of radon to escape from the deeper soil, giving radon flux values of 90-100 Bq m-2 h-1 . These radon flux values are much higher than the average radon flux over the Earth, which is about 50 Bq m-2 h-1 (Szegvary et al, 2009). On the other hand, this geographical area is frequently affected by snow and rain events which drastically reduce the local radon exhalation. It is also influenced by winds coming from the Atlantic Ocean, which are poor in radon and strong, causing an important mixing. In addition, the cold nights' stability leads to an observed nocturnal radon accumulation. All the aforementioned conditions influence atmospheric radon concentrations measured at the GIC3 station, enlarging the range

  16. Continuity of non-uniform recursive subdivision surfaces

    Institute of Scientific and Technical Information of China (English)

    秦开怀; 王华维

    2000-01-01

    Since Doo-Sabin and Catmull-Clark surfaces were proposed in 1978, eigenstructure, convergence and continuity analyses of stationary subdivision have been performed very well, but it has been very difficult to prove the convergence and continuity of non-uniform recursive subdivision surfaces (NURSSes, for short) of arbitrary topology. In fact, so far a problem whether or not there exists the limit surface as well as G1 continuity of a non-uniform Catmull-Clark subdivision has not been solved yet. Here the concept of equivalent knot spacing is introduced. A new technique for eigenanaly-sis, convergence and continuity analyses of non-uniform Catmull-Clark surfaces is proposed such that the convergence and G1 continuity of NURSSes at extraordinary points are proved. In addition, slightly improved rules for NURSSes are developed. This offers us one more alternative for modeling free-form surfaces of arbitrary topologies with geometric features such as cusps, sharp edges, creases and darts, while elsewhere ma

  17. Fitting C² continuous parametric surfaces to frontiers delimiting physiologic structures.

    Science.gov (United States)

    Bayer, Jason D; Epstein, Matthew; Beaumont, Jacques

    2014-01-01

    We present a technique to fit C(2) continuous parametric surfaces to scattered geometric data points forming frontiers delimiting physiologic structures in segmented images. Such mathematical representation is interesting because it facilitates a large number of operations in modeling. While the fitting of C(2) continuous parametric curves to scattered geometric data points is quite trivial, the fitting of C(2) continuous parametric surfaces is not. The difficulty comes from the fact that each scattered data point should be assigned a unique parametric coordinate, and the fit is quite sensitive to their distribution on the parametric plane. We present a new approach where a polygonal (quadrilateral or triangular) surface is extracted from the segmented image. This surface is subsequently projected onto a parametric plane in a manner to ensure a one-to-one mapping. The resulting polygonal mesh is then regularized for area and edge length. Finally, from this point, surface fitting is relatively trivial. The novelty of our approach lies in the regularization of the polygonal mesh. Process performance is assessed with the reconstruction of a geometric model of mouse heart ventricles from a computerized tomography scan. Our results show an excellent reproduction of the geometric data with surfaces that are C(2) continuous.

  18. Constructing C1 Continuous Surface on Irregular Quad Meshes

    Institute of Scientific and Technical Information of China (English)

    HE Jun; GUO Qiang

    2013-01-01

    A new method is proposed for surface construction on irregular quad meshes as extensions to uniform B-spline surfaces. Given a number of control points, which form a regular or irregular quad mesh, a weight function is constructed for each control point. The weight function is defined on a local domain and is C1 continuous. Then the whole surface is constructed by the weighted combination of all the control points. The property of the new method is that the surface is defined by piecewise C1 bi-cubic rational parametric polynomial with each quad face. It is an extension to uniform B-spline surfaces in the sense that its definition is an analogy of the B-spline surface, and it produces a uniform bi-cubic B-spline surface if the control mesh is a regular quad mesh. Examples produced by the new method are also included.

  19. Surface electromyography of continuous drinking in healthy adults.

    Science.gov (United States)

    Vaiman, Michael; Gabriel, Chaim; Eviatar, Ephraim; Segal, Samuel

    2005-01-01

    To give a description of normal surface electromyography (sEMG) aspects of uninterrupted (continuous) drinking and to establish normal sEMG values for swallowing 100 mL of water. Prospective observational study of healthy volunteers. Four hundred twenty apparently healthy male and female volunteers divided into three age groups (18-40, 41-65, 66+ years). The evaluated parameters included the total duration, number of swallows, amount of water per swallow, and voltage of the EMG activity of the orbicularis oris, masseter, and submental-submandibular muscles and the infrahyoid muscle groups covered by the m. platysma. The overall normal mean values for duration, number of swallows, and amplitude of muscle activity during continuous drinking were compiled. The age-related increase in duration of swallows and of total drinking time was significant only in the older group (95% confidence interval, P or = .05). The mean electric activity (in muV) varied insignificantly among the age groups. The activity of the m. orbicularis oris was the least informative. An unexpectedly significant number of healthy subjects (14.25%, P swallow after drinking. The establishment of normal sEMG levels now makes this modality applicable for evaluating the swallowing mechanism among adults for potentially identifying and ruling out abnormalities. Its simplicity, noninvasiveness, and low level of discomfort also make it highly suitable for screening purposes.

  20. Note: Continuous synthesis of uniform vertical graphene on cylindrical surfaces.

    Science.gov (United States)

    Bo, Zheng; Cui, Shumao; Yu, Kehan; Lu, Ganhua; Mao, Shun; Chen, Junhong

    2011-08-01

    This note describes a new reactor design for continuous synthesis of vertically oriented graphene (VG) sheets on cylindrical wire substrates using an atmospheric plasma-enhanced chemical vapor deposition (PECVD) system. Through combining a U-shaped reactor design with "dynamic mode" synthesis featuring simultaneous rotational and axial movements of the metallic wire substrate, the new setup can enable continuous synthesis of VG sheets on the wire surface with remarkable uniformity in both circumferential and axial directions. In contrast, synthesis of VG at "static mode" with a fixed substrate can only lead to non-uniform growth of VG sheets on the wire surface. Potential applications of the resulting uniform-VG-coated metallic wire could include field emitters, field-ionization-based neutral atom detectors, and indoor corona discharges.

  1. A continuous-vorticity panel method for lifting surfaces

    Science.gov (United States)

    Yen, A.; Mook, D. T.; Nayfeh, A. H.

    1981-01-01

    A continuous-vorticity panel method is developed and utilized to predict the steady aerodynamic loads on lifting surfaces having sharp-edge separation. Triangular panels with linearly varying vorticity are used. The velocity field generated by an individual element is obtained in closed form. An optimization scheme is constructed for finding the vorticity at the nodes of the elements. The method is not restricted by aspect ratios, angles of attack, planforms, or camber. Rectangular and delta wings are presented as numerical examples. The numerical results are in good agreement with the experimental data for incompressible flows.

  2. A continuous surface reconstruction method on point cloud captured from a 3D surface photogrammetry system

    Science.gov (United States)

    Liu, Wenyang; Cheung, Yam; Sabouri, Pouya; Arai, Tatsuya J.; Sawant, Amit; Ruan, Dan

    2015-01-01

    Purpose: To accurately and efficiently reconstruct a continuous surface from noisy point clouds captured by a surface photogrammetry system (VisionRT). Methods: The authors have developed a level-set based surface reconstruction method on point clouds captured by a surface photogrammetry system (VisionRT). The proposed method reconstructs an implicit and continuous representation of the underlying patient surface by optimizing a regularized fitting energy, offering extra robustness to noise and missing measurements. By contrast to explicit/discrete meshing-type schemes, their continuous representation is particularly advantageous for subsequent surface registration and motion tracking by eliminating the need for maintaining explicit point correspondences as in discrete models. The authors solve the proposed method with an efficient narrowband evolving scheme. The authors evaluated the proposed method on both phantom and human subject data with two sets of complementary experiments. In the first set of experiment, the authors generated a series of surfaces each with different black patches placed on one chest phantom. The resulting VisionRT measurements from the patched area had different degree of noise and missing levels, since VisionRT has difficulties in detecting dark surfaces. The authors applied the proposed method to point clouds acquired under these different configurations, and quantitatively evaluated reconstructed surfaces by comparing against a high-quality reference surface with respect to root mean squared error (RMSE). In the second set of experiment, the authors applied their method to 100 clinical point clouds acquired from one human subject. In the absence of ground-truth, the authors qualitatively validated reconstructed surfaces by comparing the local geometry, specifically mean curvature distributions, against that of the surface extracted from a high-quality CT obtained from the same patient. Results: On phantom point clouds, their method

  3. A continuous surface reconstruction method on point cloud captured from a 3D surface photogrammetry system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenyang [Department of Bioengineering, University of California, Los Angeles, California 90095 (United States); Cheung, Yam; Sabouri, Pouya; Arai, Tatsuya J.; Sawant, Amit [Department of Radiation Oncology, University of Texas Southwestern, Dallas, Texas 75390 (United States); Ruan, Dan, E-mail: druan@mednet.ucla.edu [Department of Bioengineering, University of California, Los Angeles, California 90095 and Department of Radiation Oncology, University of California, Los Angeles, California 90095 (United States)

    2015-11-15

    Purpose: To accurately and efficiently reconstruct a continuous surface from noisy point clouds captured by a surface photogrammetry system (VisionRT). Methods: The authors have developed a level-set based surface reconstruction method on point clouds captured by a surface photogrammetry system (VisionRT). The proposed method reconstructs an implicit and continuous representation of the underlying patient surface by optimizing a regularized fitting energy, offering extra robustness to noise and missing measurements. By contrast to explicit/discrete meshing-type schemes, their continuous representation is particularly advantageous for subsequent surface registration and motion tracking by eliminating the need for maintaining explicit point correspondences as in discrete models. The authors solve the proposed method with an efficient narrowband evolving scheme. The authors evaluated the proposed method on both phantom and human subject data with two sets of complementary experiments. In the first set of experiment, the authors generated a series of surfaces each with different black patches placed on one chest phantom. The resulting VisionRT measurements from the patched area had different degree of noise and missing levels, since VisionRT has difficulties in detecting dark surfaces. The authors applied the proposed method to point clouds acquired under these different configurations, and quantitatively evaluated reconstructed surfaces by comparing against a high-quality reference surface with respect to root mean squared error (RMSE). In the second set of experiment, the authors applied their method to 100 clinical point clouds acquired from one human subject. In the absence of ground-truth, the authors qualitatively validated reconstructed surfaces by comparing the local geometry, specifically mean curvature distributions, against that of the surface extracted from a high-quality CT obtained from the same patient. Results: On phantom point clouds, their method

  4. Mirror reactor surface study

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, A. L.; Damm, C. C.; Futch, A. H.; Hiskes, J. R.; Meisenheimer, R. G.; Moir, R. W.; Simonen, T. C.; Stallard, B. W.; Taylor, C. E.

    1976-09-01

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included.

  5. Volume Continuation of potential fields from the minimum-length solution: An optimal tool for continuation through general surfaces

    Science.gov (United States)

    Mastellone, Daniela; Fedi, Maurizio; Ialongo, Simone; Paoletti, Valeria

    2014-12-01

    Many methods have been used to upward continue potential field data. Most techniques employ the Fast Fourier transform, which is an accurate, quick way to compute level-to-level upward continuation or spatially varying scale filters for level-to-draped surfaces. We here propose a new continuation approach based on the minimum-length solution of the inverse potential field problem, which we call Volume Continuation (VOCO). For real data the VOCO is obtained as the regularized solution to the Tikhonov problem. We tested our method on several synthetic examples involving all types of upward continuation and downward continuation (level-to-level, level-to-draped, draped-to-level, draped-to-draped). We also employed the technique to upward continue to a constant height (2500 m a.s.l.), the high-resolution draped aeromagnetic data of the Ischia Island in Southern Italy. We found that, on the average, they are consistent with the aeromagnetic regional data measured at the same altitude. The main feature of our method is that it does not only provide continued data over a specified surface, but it yields a volume of upward continuation. For example, the continued data refers to a volume and thus, any surface may be easily picked up within the volume to get upward continuation to different surfaces. This approach, based on inversion of the measured data, tends to be especially advantageous over the classical techniques when dealing with draped-to-level upward continuation. It is also useful to obtain a more stable downward continuation and to continue noisy data. The inversion procedure involved in the method implies moderate computational costs, which are well compensated by getting a 3D set of upward continued data to achieve high quality results.

  6. Surface adhesive properties of continuous PBO fiber after air-plasma-grafting-epoxy treatment

    Institute of Scientific and Technical Information of China (English)

    贾彩霞; 王乾; 陈平; 蒲永伟

    2016-01-01

    It was found that air dielectric barrier discharge (DBD) plasma contributed to the grafting of epoxy resin onto continuous PBO fiber surface. This air-plasma-grafting-epoxy method yielded a noticeable enhancement in the interfacial adhesion between PBO fiber and thermoplastic matrix resin, with the interlaminar shear strength of the resulting composites increased by 66.7%. DSC and FTIR analyses were then used to study the curing behavior of epoxy coating on PBO fiber surface, deduce the possible grafting reactions and investigate the grafting mechanism. More importantly, TGA measurement showed that the grafting of epoxy onto PBO fiber had almost no effect on the composite heat resistance, and there was more thermoplastic matrix resin adhering to the fiber surface; the latter could also be clearly found in the SEM photos. Thereby, the air-plasma-grafting-epoxy treatment was proved to be an effective method for the improvement of continuous PBO fiber surface adhesive properties.

  7. Theoretical and methodological studies of continuous microbial bioreactors.

    Science.gov (United States)

    Toda, Kiyoshi

    2003-08-01

    This article reviews most of the author's studies on process development and reactor design for continuous microbial reactions. (1) Enzyme reactions of growing and non-growing microbial cells immobilized in agar gel beads were analyzed pertaining to the effects of external and internal diffusion of substrate on reaction kinetics. (2) Experimental correlations of production rates of beta-fructosidase and acid phosphatase with dilution rate of continuous culture were simulated based on an operon model for enzyme regulation. (3) Population dynamics of an amylase-producing bacteria and their mutant were discussed in relation to enzyme productivity in a continuous culture of spore-forming bacteria. (4) Plasmid mobilization in a mixed population of donor, recipient, and helper cells was investigated in a continuous culture as a model study of accidental release of a genetically modified plasmid into a natural environment. (5) A production rate increase of up to 100-fold was achieved by cell-recycle culturing of continuous acetic acid fermentation using a filter module with a hollow fiber membrane. (6) The feasibility of a continuous surface culture for the biooxidation of organic substances was ascribed to an enhanced oxygen absorption rate in the presence of a microbial film on a liquid surface. (7) Simultaneous separation of inhibitory products using an electrodialysis module during some organic acid fermentations was effective for increasing production in a continuous culture.

  8. Continuous Estimation of Wrist Torque from Surface EMG Signals Using Path-dependent Model

    Institute of Scientific and Technical Information of China (English)

    PAN Li-zhi; ZHANG Ding-guo; SHENG Xin-jun; ZHU Xiang-yang

    2014-01-01

    Continuous estimation of wrist torque from surface electromyography (EMG) signals has been studied by some research institutes. Hysteresis effect is a phenomenon in EMG force relationship. In this work, a path-dependent model based on hysteresis effect was used for continuously estimating wrist torque from surface EMG signals. The surface EMG signals of the flexor carpi ulnaris (FCU) and extensor carpi radialis (ECR) were collected along with wrist torque of flexion/extension degree-of-freedom. EMG signal of FCU was used to estimate the torque of wrist flexion and EMG signal of ECR to estimate the torque of wrist extension. The existence of hysteresis effect has been proven either during wrist flexion or extension on all subjects. And the estimation performance of path-dependent model is much better than the overall model. Thus, the path-dependent model is suitable to improve the wrist torque's estimation accuracy.

  9. Continuous Rating for Diggability Assessment in Surface Mines

    Science.gov (United States)

    IPHAR, Melih

    2016-10-01

    The rocks can be loosened either by drilling-blasting or direct excavation using powerful machines in opencast mining operations. The economics of rock excavation is considered for each method to be applied. If blasting operation is not preferred and also the geological structures and rock mass properties in site are convenient (favourable ground conditions) for ripping or direct excavation method by mining machines, the next step is to determine which machine or excavator should be selected for the excavation purposes. Many researchers have proposed several diggability or excavatability assessment methods for deciding on excavator type to be used in the field. Most of these systems are generally based on assigning a rating for the parameters having importance in rock excavation process. However, the sharp transitions between the two adjacent classes for a given parameter can lead to some uncertainties. In this paper, it has been proposed that varying rating should be assigned for a given parameter called as “continuous rating” instead of giving constant rating for a given class.

  10. Plant and soil modifications by continuous surface effluent application

    Energy Technology Data Exchange (ETDEWEB)

    Tedesco, M.J.; Levien, R. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. of Solos; Mohrdieck, F.G.; Rodrigues, N.R. [CORSAN-SITEL, Triunfo, RS (Brazil). Polo Petroquimico do Sul. Dept. de Operacao e Manutencao; Flores, A.I.P.

    1993-12-31

    In order to study the effects on soil and plants of the liquid effluent generated by a the Integrated Liquid Effluent Treatment System of a large Brazilian petrochemical complex, a field study was conducted in four areas which received the effluent and compared to control sites. This work presents some results of this study. 12 refs., 1 fig., 3 tabs.

  11. Surface finish measurement studies

    Science.gov (United States)

    Teague, E. C.

    1983-01-01

    The performance of stylus instruments for measuring the topography of National Transonic Facility (NTF) model surfaces both for monitoring during fabrication and as an absolute measurement of topography was evaluated. It was found that the shop-grade instruments can damage the surface of models and that their use for monitoring fabrication procedures can lead to surface finishes that are substantially out of range in critical areas of the leading edges. The development of a prototype light-scattering instrument which would allow for rapid assessment of the surface finish of a model is also discussed.

  12. Continuous wavelet transform and discrete multi-resolution analysis of surface fluxes and atmospheric stability

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Variations of land surface fluxes of sensible heat (H), latent heat ( LE ), and CO2(F-CO2) obtained from the eddy-covariance measurements above a winter wheat field from March 30 to April 24, 2001 have been studied at scales ranging from 10 minutes to days. Wavelet transform is used in the analysis of land surface fluxes and atmospheric stability (ζ) calculated from the measurements to reveal the changes in land surface fluxes in hours to days scales. The main results are: (1) Concise and compact information about the fluxes, net radiation (Rn), temperature (T) and ζ in the scale-time domain are extracted from the data by continuous wavelet analysis,and 1 day, 0.5 day and short-period (shorter than 0.5 day) components are revealed. Continuous wavelet coefficients can be used to characterize periodic components of changes in fluxes and ζ. (2) Discrete-time multi-resolution analysis can be used to concentrate total energy variance of time series of the measurements to a small number of coefficients, plotting the relative energy distribution to get several meaningful characteristics of the data. (3) Under neutral atmospheric conditions, the relative energy distributions of the Haar multi-resolution analysis of the three non-dimensional coefficients (T/T* , q/q * and c/c * ) display clear similarities.

  13. An Intuitive Approach to Geometric Continuity for Parametric Curves and Surfaces (Extended Abstract)

    Science.gov (United States)

    Derose, T. D.; Barsky, B. A.

    1985-01-01

    The notion of geometric continuity is extended to an arbitrary order for curves and surfaces, and an intuitive development of constraints equations is presented that are necessary for it. The constraints result from a direct application of the univariate chain rule for curves, and the bivariate chain rule for surfaces. The constraints provide for the introduction of quantities known as shape parameters. The approach taken is important for several reasons: First, it generalizes geometric continuity to arbitrary order for both curves and surfaces. Second, it shows the fundamental connection between geometric continuity of curves and geometric continuity of surfaces. Third, due to the chain rule derivation, constraints of any order can be determined more easily than derivations based exclusively on geometric measures.

  14. Continuous directional water transport on the peristome surface of Nepenthes alata

    Science.gov (United States)

    Chen, Huawei; Zhang, Pengfei; Zhang, Liwen; Liu, Hongliang; Jiang, Ying; Zhang, Deyuan; Han, Zhiwu; Jiang, Lei

    2016-04-01

    Numerous natural systems contain surfaces or threads that enable directional water transport. This behaviour is usually ascribed to hierarchical structural features at the microscale and nanoscale, with gradients in surface energy and gradients in Laplace pressure thought to be the main driving forces. Here we study the prey-trapping pitcher organs of the carnivorous plant Nepenthes alata. We find that continuous, directional water transport occurs on the surface of the ‘peristome’—the rim of the pitcher—because of its multiscale structure, which optimizes and enhances capillary rise in the transport direction, and prevents backflow by pinning in place any water front that is moving in the reverse direction. This results not only in unidirectional flow despite the absence of any surface-energy gradient, but also in a transport speed that is much higher than previously thought. We anticipate that the basic ‘design’ principles underlying this behaviour could be used to develop artificial fluid-transport systems with practical applications.

  15. Study progresses on continuous curvilinear capsulorhexis

    Directory of Open Access Journals (Sweden)

    Bo Gao

    2015-10-01

    Full Text Available As the progress of modern techniques for cataract extraction surgery and various needs of intraocular lens(IOLimplantation, continuous curvilinear capsulorhexis(CCCis still in absolute dominance among different ways of incision of anterior capsular lens in clinical practices, due to its advantages such as smoothness of capsulor opening, strong anti-tearing ability, integrity of supporting capsular bag, and strength at maintaining IOL stability. This article describes in general the historical development of CCC and complementary methods adapted to raise success rate when it is used in special cases of cataract extraction surgery. Meanwhile, the article also discusses briefly and envisions the prospects of femotsecond laser applied in CCC technique for cataract extraction.

  16. Continuously Tunable Wettability by Using Surface Patterned Shape Memory Polymers with Giant Deformability.

    Science.gov (United States)

    Zhao, Lingyu; Zhao, Jun; Liu, Yayun; Guo, Yufeng; Zhang, Liangpei; Chen, Zhuo; Zhang, Hui; Zhang, Zhong

    2016-06-01

    Designing smart surfaces with tunable wettability has drawn much attention in recent years for academic research and practical applications. Most of the previous methods to achieve such surfaces demand some particular materials that inherently have special features or complicated structures which are usually not easy to obtain. A novel strategy to achieve such smart surfaces is proposed by using the surface patterned shape memory polymers of chemically crosslinked polycyclooctene which shows a giant deformability of up to ≈730% strain. The smart surfaces possess the ability to continuously tune the wettability by controlling the recovery temperature and/or time. Coating the modified titanium dioxide nanoparticles onto such surfaces renders the surface superhydrophobicity and expands the tunable range of contact angles (CAs). Theoretical calculations of the CAs at different strains via modified Cassie model well explain the tunable wettability behaviors of such smart surfaces.

  17. Marketing Continuing Education: A Study of Price Strategies. Occasional Papers in Continuing Education, No. 11.

    Science.gov (United States)

    Lamoureux, Marvin E.

    The objective of the study conducted at the Centre for Continuing Education (CCE) at the University of British Columbia was to determine that threshold pricing not only existed for continuing education courses, but also was applicable to an administrative decision-making structure. The first part of the three-part investigation analyzed consumer…

  18. Plasma-mediated inactivation of Pseudomonas aeruginosa biofilms grown on borosilicate surfaces under continuous culture system.

    Directory of Open Access Journals (Sweden)

    Kurt G Vandervoort

    Full Text Available Biofilms are microbial communities attached to a surface and embedded in a matrix composed of exopolysaccharides and excreted nucleic acids. Bacterial biofilms are responsible for undesirable effects such as disease, prostheses colonization, biofouling, equipment damage, and pipe plugging. Biofilms are also more resilient than free-living cells to regular sterilization methods and therefore it is indispensable to develop better ways to control and remove them. The use of gas discharge plasmas is a good alternative since plasmas contain a mixture of reactive agents well-known for their decontamination potential against free microorganisms. We have previously reported that Pseudomonas aeruginosa biofilms were inactivated after a 1-min plasma exposure. We determined that the adhesiveness and the thickness of Pseudomonas biofilms grown on borosilicate were reduced. We also reported sequential morphological changes and loss of viability upon plasma treatment. However, the studies were carried out in batch cultures. The use of a continuous culture results in a more homogenous environment ensuring reproducible biofilm growth. The aim of this work was to study plasma-mediated inactivation of P. aeruginosa biofilms grown on borosilicate in a continuous culture system. In this paper we show that biofilms grown on glass under continuous culture can be inactivated by using gas discharge plasma. Both biofilm architecture and cell culturability are impacted by the plasma treatment. The inactivation kinetics is similar to previously described ones and cells go through sequential changes ranging from minimal modification without loss of viability at short plasma exposure times, to major structure and viability loss at longer exposure times. We report that changes in biofilm structure leading to the loss of culturability and viability are related to a decrease of the biofilm matrix adhesiveness. To our knowledge, there has been no attempt to evaluate the

  19. Plasma-mediated inactivation of Pseudomonas aeruginosa biofilms grown on borosilicate surfaces under continuous culture system.

    Science.gov (United States)

    Vandervoort, Kurt G; Brelles-Mariño, Graciela

    2014-01-01

    Biofilms are microbial communities attached to a surface and embedded in a matrix composed of exopolysaccharides and excreted nucleic acids. Bacterial biofilms are responsible for undesirable effects such as disease, prostheses colonization, biofouling, equipment damage, and pipe plugging. Biofilms are also more resilient than free-living cells to regular sterilization methods and therefore it is indispensable to develop better ways to control and remove them. The use of gas discharge plasmas is a good alternative since plasmas contain a mixture of reactive agents well-known for their decontamination potential against free microorganisms. We have previously reported that Pseudomonas aeruginosa biofilms were inactivated after a 1-min plasma exposure. We determined that the adhesiveness and the thickness of Pseudomonas biofilms grown on borosilicate were reduced. We also reported sequential morphological changes and loss of viability upon plasma treatment. However, the studies were carried out in batch cultures. The use of a continuous culture results in a more homogenous environment ensuring reproducible biofilm growth. The aim of this work was to study plasma-mediated inactivation of P. aeruginosa biofilms grown on borosilicate in a continuous culture system. In this paper we show that biofilms grown on glass under continuous culture can be inactivated by using gas discharge plasma. Both biofilm architecture and cell culturability are impacted by the plasma treatment. The inactivation kinetics is similar to previously described ones and cells go through sequential changes ranging from minimal modification without loss of viability at short plasma exposure times, to major structure and viability loss at longer exposure times. We report that changes in biofilm structure leading to the loss of culturability and viability are related to a decrease of the biofilm matrix adhesiveness. To our knowledge, there has been no attempt to evaluate the inactivation

  20. 42 CFR 431.713 - Continuing study and investigation.

    Science.gov (United States)

    2010-10-01

    ... SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS STATE ORGANIZATION AND GENERAL ADMINISTRATION State Programs for Licensing Nursing Home Administrators § 431.713 Continuing study and investigation. The agency or board must conduct a continuing study of nursing homes and administrators within the State...

  1. Fitting C2 Continuous Parametric Surfaces to Frontiers Delimiting Physiologic Structures

    Directory of Open Access Journals (Sweden)

    Jason D. Bayer

    2014-01-01

    Full Text Available We present a technique to fit C2 continuous parametric surfaces to scattered geometric data points forming frontiers delimiting physiologic structures in segmented images. Such mathematical representation is interesting because it facilitates a large number of operations in modeling. While the fitting of C2 continuous parametric curves to scattered geometric data points is quite trivial, the fitting of C2 continuous parametric surfaces is not. The difficulty comes from the fact that each scattered data point should be assigned a unique parametric coordinate, and the fit is quite sensitive to their distribution on the parametric plane. We present a new approach where a polygonal (quadrilateral or triangular surface is extracted from the segmented image. This surface is subsequently projected onto a parametric plane in a manner to ensure a one-to-one mapping. The resulting polygonal mesh is then regularized for area and edge length. Finally, from this point, surface fitting is relatively trivial. The novelty of our approach lies in the regularization of the polygonal mesh. Process performance is assessed with the reconstruction of a geometric model of mouse heart ventricles from a computerized tomography scan. Our results show an excellent reproduction of the geometric data with surfaces that are C2 continuous.

  2. Fitting C 2 Continuous Parametric Surfaces to Frontiers Delimiting Physiologic Structures

    Science.gov (United States)

    Bayer, Jason D.

    2014-01-01

    We present a technique to fit C 2 continuous parametric surfaces to scattered geometric data points forming frontiers delimiting physiologic structures in segmented images. Such mathematical representation is interesting because it facilitates a large number of operations in modeling. While the fitting of C 2 continuous parametric curves to scattered geometric data points is quite trivial, the fitting of C 2 continuous parametric surfaces is not. The difficulty comes from the fact that each scattered data point should be assigned a unique parametric coordinate, and the fit is quite sensitive to their distribution on the parametric plane. We present a new approach where a polygonal (quadrilateral or triangular) surface is extracted from the segmented image. This surface is subsequently projected onto a parametric plane in a manner to ensure a one-to-one mapping. The resulting polygonal mesh is then regularized for area and edge length. Finally, from this point, surface fitting is relatively trivial. The novelty of our approach lies in the regularization of the polygonal mesh. Process performance is assessed with the reconstruction of a geometric model of mouse heart ventricles from a computerized tomography scan. Our results show an excellent reproduction of the geometric data with surfaces that are C 2 continuous. PMID:24782911

  3. Advanced surface chemical analysis of continuously manufactured drug loaded composite pellets.

    Science.gov (United States)

    Hossain, Akter; Nandi, Uttom; Fule, Ritesh; Nokhodchi, Ali; Maniruzzaman, Mohammed

    2017-04-15

    The aim of the present study was to develop and characterise polymeric composite pellets by means of continuous melt extrusion techniques. Powder blends of a steroid hormone (SH) as a model drug and either ethyl cellulose (EC N10 and EC P7 grades) or hydroxypropyl methylcellulose (HPMC AS grade) as polymeric carrier were extruded using a Pharma 11mm twin screw extruder in a continuous mode of operation to manufacture extruded composite pellets of 1mm length. Molecular modelling study using commercial Gaussian 09 software outlined a possible drug-polymer interaction in the molecular level to develop solid dispersions of the drug in the pellets. Solid-state analysis conducted via a differential scanning calorimetry (DSC), hot stage microscopy (HSM) and X-ray powder diffraction (XRPD) analyses revealed the amorphous state of the drug in the polymer matrices. Surface analysis using SEM/energy dispersive X-ray (EDX) of the produced pellets arguably showed a homogenous distribution of the C and O atoms in the pellet matrices. Moreover, advanced chemical surface analysis conducted via atomic force microscopy (AFM) showed a homogenous phase system having the drug molecule dispersed onto the amorphous matrices while Raman mapping confirmed the homogenous single-phase drug distribution in the manufactured composite pellets. Such composite pellets are expected to deliver multidisciplinary applications in drug delivery and medical sciences by e.g. modifying drug solubility/dissolutions or stabilizing the unstable drug (e.g. hormone, protein) in the composite network. Copyright © 2016. Published by Elsevier Inc.

  4. Registering cortical surfaces based on whole-brain structural connectivity and continuous connectivity analysis.

    Science.gov (United States)

    Gutman, Boris; Leonardo, Cassandra; Jahanshad, Neda; Hibar, Derrek; Eschenburg, Kristian; Nir, Talia; Villalon, Julio; Thompson, Paul

    2014-01-01

    We present a framework for registering cortical surfaces based on tractography-informed structural connectivity. We define connectivity as a continuous kernel on the product space of the cortex, and develop a method for estimating this kernel from tractography fiber models. Next, we formulate the kernel registration problem, and present a means to non-linearly register two brains' continuous connectivity profiles. We apply theoretical results from operator theory to develop an algorithm for decomposing the connectome into its shared and individual components. Lastly, we extend two discrete connectivity measures to the continuous case, and apply our framework to 98 Alzheimer's patients and controls. Our measures show significant differences between the two groups.

  5. A tri-continuous mesoporous material with a silica pore wall following a hexagonal minimal surface

    KAUST Repository

    Han, Yu

    2009-04-06

    Ordered porous materials with unique pore structures and pore sizes in the mesoporous range (2-50nm) have many applications in catalysis, separation and drug delivery. Extensive research has resulted in mesoporous materials with one-dimensional, cage-like and bi-continuous pore structures. Three families of bi-continuous mesoporous materials have been made, with two interwoven but unconnected channels, corresponding to the liquid crystal phases used as templates. Here we report a three-dimensional hexagonal mesoporous silica, IBN-9, with a tri-continuous pore structure that is synthesized using a specially designed cationic surfactant template. IBN-9 consists of three identical continuous interpenetrating channels, which are separated by a silica wall that follows a hexagonal minimal surface. Such a tri-continuous mesostructure was predicted mathematically, but until now has not been observed in real materials. © 2009 Macmillan Publishers Limited. All rights reserved.

  6. Continuous droplet removal upon dropwise condensation of humid air on a hydrophobic micropatterned surface.

    Science.gov (United States)

    Zamuruyev, Konstantin O; Bardaweel, Hamzeh K; Carron, Christopher J; Kenyon, Nicholas J; Brand, Oliver; Delplanque, Jean-Pierre; Davis, Cristina E

    2014-08-26

    Combination of two physical phenomena, capillary pressure gradient and wettability gradient, allows a simple two-step fabrication process that yields a reliable hydrophobic self-cleaning condenser surface. The surface is fabricated with specific microscopic topography and further treatment with a chemically inert low-surface-energy material. This process does not require growth of nanofeatures (nanotubes) or hydrophilic-hydrophobic patterning of the surface. Trapezoidal geometry of the microfeatures facilitates droplet transfer from the Wenzel to the Cassie state and reduces droplet critical diameter. The geometry of the micropatterns enhances local coalescence and directional movement for droplets with diameter much smaller than the radial length of the micropatterns. The hydrophobic self-cleaning micropatterned condenser surface prevents liquid film formation and promotes continuous dropwise condensation cycle. Upon dropwise condensation, droplets follow a designed wettability gradient created with micropatterns from the most hydrophobic to the least hydrophobic end of the surface. The surface has higher condensation efficiency, due to its directional self-cleaning property, than a plain hydrophobic surface. We explain the self-actuated droplet collection mechanism on the condenser surface and demonstrate experimentally the creation of an effective wettability gradient over a 6 mm radial distance. In spite of its fabrication simplicity, the fabricated surface demonstrates self-cleaning property, enhanced condensation performance, and reliability over time. Our work enables creation of a hydrophobic condenser surface with the directional self-cleaning property that can be used for collection of biological (chemical, environmental) aerosol samples or for condensation enhancement.

  7. Continuous electrocoagulation of cheese whey wastewater: an application of Response Surface Methodology.

    Science.gov (United States)

    Tezcan Un, Umran; Kandemir, Ayse; Erginel, Nihal; Ocal, S Eren

    2014-12-15

    In this study, treatment of cheese whey wastewater was performed using a uniquely-designed continuous electrocoagulation reactor, not previously encountered in the literature. An iron horizontal rotating screw type anode was used in the continuous mode. An empirical model, in terms of effective operational factors, such as current density (40, 50, 60 mA/cm(2)), pH (3, 5, 7) and retention time (20, 40, 60 min), was developed through Response Surface Methodology. An optimal region characterized by low values of Chemical Oxygen Demand (COD) was determined. As a result of experiments, a linear effect in the removal efficiency of COD was obtained for current density and retention time, while the initial pH of the wastewater was found to have a quadratic effect in the removal efficiency of COD. The best fit nonlinear mathematical model, with a coefficient of determination value (R(2)) of 85%, was defined. An initial COD concentration of 15.500 mg/L was reduced to 2112 mg/L with a removal efficiency of 86.4%. In conclusion, it can be said that electrocoagulation was successfully applied for the treatment of cheese whey wastewater.

  8. Data of continuous harvest of stem cells via partial detachment from thermoresponsive nanobrush surfaces

    Directory of Open Access Journals (Sweden)

    Chin-Chen Yeh

    2016-03-01

    Full Text Available This data article contains two figures and one table supporting the research article entitled: “Continuous harvest of stem cells via partial detachment from thermoresponsive nanobrush surface” [1]. The table shows coating conditions of three copolymers, poly(styrene-co-acrylic acid grafted with oligovitronectin, poly(styrene-co-N-isopropylacrylamide and poly(styrene-co-polyethylene glycol methacrylate to prepare thermoresponsive surface. XPS spectra show the nitrogen peak of the polystyrene surface coated with poly(styrene-co-acrylic acid grafted with oligovitronectin. The surface coating density analyzed from sorption of poly(styrene-co-acrylic acid grafted with oligovitronectin by UV–vis spectroscopy is also presented.

  9. Variational space-time (dis)continuous Galerkin method for linear free surface waves

    NARCIS (Netherlands)

    Ambati, V.R.; Vegt, van der J.J.W.; Bokhove, O.

    2008-01-01

    A new variational (dis)continuous Galerkin finite element method is presented for the linear free surface gravity water wave equations. We formulate the space-time finite element discretization based on a variational formulation analogous to Luke's variational principle. The linear algebraic system

  10. Continuous Compressed Sensing for Surface Dynamical Processes with Helium Atom Scattering

    Science.gov (United States)

    Jones, Alex; Tamtögl, Anton; Calvo-Almazán, Irene; Hansen, Anders

    2016-06-01

    Compressed Sensing (CS) techniques are used to measure and reconstruct surface dynamical processes with a helium spin-echo spectrometer for the first time. Helium atom scattering is a well established method for examining the surface structure and dynamics of materials at atomic sized resolution and the spin-echo technique opens up the possibility of compressing the data acquisition process. CS methods demonstrating the compressibility of spin-echo spectra are presented for several measurements. Recent developments on structured multilevel sampling that are empirically and theoretically shown to substantially improve upon the state of the art CS techniques are implemented. In addition, wavelet based CS approximations, founded on a new continuous CS approach, are used to construct continuous spectra. In order to measure both surface diffusion and surface phonons, which appear usually on different energy scales, standard CS techniques are not sufficient. However, the new continuous CS wavelet approach allows simultaneous analysis of surface phonons and molecular diffusion while reducing acquisition times substantially. The developed methodology is not exclusive to Helium atom scattering and can also be applied to other scattering frameworks such as neutron spin-echo and Raman spectroscopy.

  11. 连续退火热镀锌板镀层表面黑点缺陷研究%Study of dark dot defect on coating surface of continuously annealed hot-dip galvanized steel sheet

    Institute of Scientific and Technical Information of China (English)

    刘李斌; 蒋光锐; 马兵智; 李蔚然; 刘华赛; 齐春雨

    2014-01-01

    研究了热镀锌板镀层表面黑点的产生机理,分析了该缺陷对热镀锌板涂镀质量的影响,提出了相应的改进措施。结果表明,基板表面存在微小凹坑,镀锌后表面形成黑色圆形氧化膜,即黑点缺陷,对热镀锌板涂镀后的磷化膜质量产生不利影响。实际生产中,通过降低热轧卷的卷曲温度、清洗槽电解电流密度及提高退火炉的密封性,可有效减轻该缺陷。%Generation mechanism of dark dot defect and effect on painting surface quality of hot -dip galvanized steel sheet were studied , and some relative improvement measures were proposed .The results show that little pits exist on the substrate , which form dark dot defect is composed of oxide film after galvanized .The dark dot defect markedly influences crystal structure of phosphate coating .Moreover , during practical production , it could be effectively reduced by decreasing coiling temperature , reducing current density in rinse tank and improving sealing of the annealing furnace .

  12. Erosion of Ag surface by continuous irradiation with slow, large Ar clusters

    Energy Technology Data Exchange (ETDEWEB)

    Rzeznik, Lukasz, E-mail: lukasz.rzeznik@uj.edu.pl [Institute of Physics, Jagiellonian University, Reymonta 4, Krakow (Poland); Paruch, Robert [Institute of Physics, Jagiellonian University, Reymonta 4, Krakow (Poland); Garrison, Barbara J. [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States); Postawa, Zbigniew, E-mail: zbigniew.postawa@uj.edu.pl [Institute of Physics, Jagiellonian University, Reymonta 4, Krakow (Poland)

    2011-07-15

    Molecular dynamics computer simulations are employed to probe processes taking place during continuous irradiation of Ag(1 1 1) surface by keV Ar{sub 872} projectiles. Surface modification, the total sputtering yield, and the angular distributions of ejected species are calculated at fluences ranging from 0 up to {approx}6 x 10{sup 13} impacts/cm{sup 2}. It has been shown that two trends can be identified in the development of surface roughness. At the beginning surface roughness increases fast. This fast increase terminates around 1 x 10{sup 13} impacts/cm{sup 2} and is followed by a slow increase that finally saturates. The effect of the surface roughness on the sputtering yield depends on the impact angle. At normal incidence the sputtering yield is rather insensitive to the development of the surface topography. Modification of the surface morphology has, however, a significant influence on the total sputtering yield at large impact angles. Both the shape of the sputtering yield dependence on the impact angle and the angular spectra of ejected particles are sensitive to the surface roughness.

  13. First principles studies on anatase surfaces

    Science.gov (United States)

    Selcuk, Sencer

    TiO2 is one of the most widely studied metal oxides from both the fundamental and the technological points of view. A variety of applications have already been developed in the fields of energy production, environmental remediation, and electronics. Still, it is considered to have a high potential for further improvement and continues to be of great interest. This thesis describes our theoretical studies on the structural and electronic properties of anatase surfaces, and their (photo)chemical behavior. Recently much attention has been focused on anatase crystals synthesized by hydrofluoric acid assisted methods. These crystals exhibit a high percentage of {001} facets, generally considered to be highly reactive. We used first principles methods to investigate the structure of these facets, which is not yet well understood. Our results suggest that (001) surfaces exhibit the bulk-terminated structure when in contact with concentrated HF solutions. However, 1x4-reconstructed surfaces, as observed in UHV, become always more stable at the typical temperatures used to clean the as-prepared crystals in experiments. Since the reconstructed surfaces are only weakly reactive, we predict that synthetic anatase crystals with dominant {001} facets should not exhibit enhanced photocatalytic activity. Understanding how defects in solids interact with external electric fields is important for technological applications such as memristor devices. We studied the influence of an external electric field on the formation energies and diffusion barriers of the surface and the subsurface oxygen vacancies at the anatase (101) surface from first principles. Our results show that the applied field can have a significant influence on the relative stabilities of these defects, whereas the effect on the subsurface-to-surface defect migration is found to be relatively minor. Charge carriers play a key role in the transport properties and the surface chemistry of TiO2. Understanding their

  14. Continuous vs. pulsating flow boiling. Part 2: Statistical comparison using response surface methodology

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Elmegaard, Brian; Meyer, Knud Erik

    2016-01-01

    Response surface methodology is used to investigate an active method for flow boiling heat transfer enhancement by means of fluid flow pulsation. The flow pulsations are introduced by a flow modulating expansion device and compared with the baseline continuous flow provided by a stepper-motor exp......Response surface methodology is used to investigate an active method for flow boiling heat transfer enhancement by means of fluid flow pulsation. The flow pulsations are introduced by a flow modulating expansion device and compared with the baseline continuous flow provided by a stepper...... pulsations is statistically significant in terms of the time-averaged flow boiling heat transfer coefficient. The cycle time range from 1 s to 9 s for the pulsations. The results show that the effect of fluid flow pulsations is statistically significant, disregarding the lowest heat flux measurements...

  15. Model for continuously scanning ultrasound vibrometer sensing displacements of randomly rough vibrating surfaces.

    Science.gov (United States)

    Ratilal, Purnima; Andrews, Mark; Donabed, Ninos; Galinde, Ameya; Rappaport, Carey; Fenneman, Douglas

    2007-02-01

    An analytic model is developed for the time-dependent ultrasound field reflected off a randomly rough vibrating surface for a continuously scanning ultrasound vibrometer system in bistatic configuration. Kirchhoff's approximation to Green's theorem is applied to model the three-dimensional scattering interaction of the ultrasound wave field with the vibrating rough surface. The model incorporates the beam patterns of both the transmitting and receiving ultrasound transducers and the statistical properties of the rough surface. Two methods are applied to the ultrasound system for estimating displacement and velocity amplitudes of an oscillating surface: incoherent Doppler shift spectra and coherent interferometry. Motion of the vibrometer over the randomly rough surface leads to time-dependent scattering noise that causes a randomization of the received signal spectrum. Simulations with the model indicate that surface displacement and velocity estimation are highly dependent upon the scan velocity and projected wavelength of the ultrasound vibrometer relative to the roughness height standard deviation and correlation length scales of the rough surface. The model is applied to determine limiting scan speeds for ultrasound vibrometer measuring ground displacements arising from acoustic or seismic excitation to be used in acoustic landmine confirmation sensing.

  16. CONTINUOUS IMPROVEMENT PRACTICE IN LARGE ENTERPRISES: STUDY RESULTS

    Directory of Open Access Journals (Sweden)

    Dorota Stadnicka

    2015-03-01

    Full Text Available Continuous improvement is indispensable for ensuring the company's development and its survival on the constantly changing global market. Continuous improvement is particularly important in the quality and production management systems. A company should deliver a product compliant with a client's requirements in a specified time and at an appropriate price. That is why, continuous improvement refers to different areas of an organization's functioning and it is an integral part of Lean Manufacturing. This article presents the results of the study conducted in production enterprises on a limited area. The aim of the study was the assessment of the implementation of continuous improvement in Lean Manufacturing, and, in particular, employees' involvement in the problem identification and in reporting improvements as well as the way of motivating employees to involve themselves. The authors also tried to identify the factors influencing the elements of a continuous improvement system.

  17. Continuous modulations of femtosecond laser-induced periodic surface structures and scanned line-widths on silicon by polarization changes.

    Science.gov (United States)

    Han, Weina; Jiang, Lan; Li, Xiaowei; Liu, Pengjun; Xu, Le; Lu, YongFeng

    2013-07-01

    Large-area, uniform laser-induced periodic surface structures (LIPSS) are of wide potential industry applications. The continuity and processing precision of LIPSS are mainly determined by the scanning intervals of adjacent scanning lines. Therefore, continuous modulations of LIPSS and scanned line-widths within one laser scanning pass are of great significance. This study proposes that by varying the laser (800 nm, 50 fs, 1 kHz) polarization direction, LIPSS and the scanned line-widths on a silicon (111) surface can be continuously modulated with high precision. It shows that the scanned line-width reaches the maximum when the polarization direction is perpendicular to the scanning direction. As an application example, the experiments show large-area, uniform LIPSS can be fabricated by controlling the scanning intervals based on the one-pass scanned line-widths. The simulation shows that the initially formed LIPSS structures induce directional surface plasmon polaritons (SPP) scattering along the laser polarization direction, which strengthens the subsequently anisotropic LIPSS fabrication. The simulation results are in good agreement with the experiments, which both support the conclusions of continuous modulations of the LIPSS and scanned line-widths.

  18. Variational space-time (dis)continuous Galerkin method for linear free surface waves

    OpenAIRE

    Ambati, V.R.; Vegt, van der, N.F.A.; Bokhove, O.

    2008-01-01

    A new variational (dis)continuous Galerkin finite element method is presented for the linear free surface gravity water wave equations. We formulate the space-time finite element discretization based on a variational formulation analogous to Luke's variational principle. The linear algebraic system of equations resulting from the finite element discretization is symmetric with a very compact stencil. To build and solve these equations, we have employed PETSc package in which a block sparse ma...

  19. Variational space-time (dis)continuous Galerkin method for nonlinear free surface waves

    OpenAIRE

    Gagarina, E; Vegt, van der, N.F.A.; Ambati, V.R.; Bokhove, O.

    2013-01-01

    A new variational finite element method is developed for nonlinear free surface gravity water waves. This method also handles waves generated by a wave maker. Its formulation stems from Miles' variational principle for water waves together with a space-time finite element discretization that is continuous in space and discontinuous in time. The key features of this formulation are: (i) a discrete variational approach that gives rise to conservation of discrete energy and phase space and prese...

  20. Theoretical Studies of Reaction Surfaces

    Science.gov (United States)

    2007-11-02

    Similar levels of agreement are being found in studies of water clusters12 , the Menshutkin reaction 13 (ion separation reaction ), a prototypical SN2 ...of both reactants and products. These analyses reveal that Bery pseudorotation occurs repeatedly during the side attack, whereas the SN2 reaction H...31 Aug 97 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS AASERT93 THEORETICAL STUDIES OF REACTION SURFACES F49620-93-1-0556 3484/XS 6. AUTHOR(S) 61103D DR

  1. Effects of continuous casting mould fluxes on reducing longitudinal and star cracks on a slab surface

    Institute of Scientific and Technical Information of China (English)

    WANG Qian; WANG Yu; CHI Jinghao; XIE Bing; HE Yuming; ZHU Bing; CHEN Wenman

    2004-01-01

    In the continuous casting production of medium carbon steel (whose mass fraction of carbon is 0.09 % to 0.16 %)and high strength Iow alloy steel (whose mass fraction of Mn is 0.90 % to 1.40 %), flecks occurring the most often are usually longitudinal and star cracks. In additional to the employment of a galvanized plate mould, two kinds; of fluxes with special properties were studied and used to harmonize the conflicts between the function of heat transfer and lubrication. An industrial application revealed that the crystallizing temperature (To) and crystal ratio (R) of fluxes have a crucible effect on impeding the occurrence of above defects on a slab surface. In the case of slab section (180 to 240) mm×(1000 to 1400) mm and casting speed Vc of (0.7 to 1.2) m/min, the optimized parameters of fluxes are Tc of (1170 to 1190) ℃, R of 80 % to 95 % for medium carbon steel, and Tc of (1100 to 1150) ℃, plus R of 40 % to 60 % for high strength Iow alloy steel.

  2. Optimization of ultrasonic assisted continuous production of biodiesel using response surface methodology.

    Science.gov (United States)

    Mostafaei, M; Ghobadian, B; Barzegar, M; Banakar, A

    2015-11-01

    This paper evaluates and optimizes the continuous production of biodiesel from waste cooking oil. In this research work, methanol and potassium hydroxide were used as catalyst engaging response surface methodology. For this purpose, the central composite experimental design (CCED), the effects of various factors such as irradiation distance, probe diameter, ultrasonic amplitude, vibration pulse and material flow into the reactor on reaction yield were studied to optimize the process. The results showed that all of the considered parameters affect the reaction efficiency significantly. The optimum combination of the findings include: irradiation distance which was 75 mm, probe diameter of 28 mm, ultrasonic amplitude of 56%, vibration pulse of 62% and flow rate of 50 ml/min that caused the reaction yield of 91.6% and energy consumption of 102.8 W. To verify this optimized combination, three tests were carried out. The results showed an average efficiency of 91.12% and 102.4 W power consumption which is well matched with the model's predictions. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Advanced surface chemical analysis of continuously manufactured drug loaded composite pellets

    OpenAIRE

    2016-01-01

    The aim of the present study was to develop and characterise polymeric composite pellets by means of continuous melt extrusion techniques. Powder blends of a steroid hormone (SH) as a model drug and either ethyl cellulose (EC N10 and EC P7 grades) or hydroxylpropyl methylcellulose (HPMC AS grade) as polymeric carrier were extruded using a Pharma 11 mm twin screw extruder in a continuous mode of operation to manufacture extruded composite pellets of 1 mm length. Molecular modelling study using...

  4. Variational space-time (dis)continuous Galerkin method for nonlinear free surface water waves

    Science.gov (United States)

    Gagarina, E.; Ambati, V. R.; van der Vegt, J. J. W.; Bokhove, O.

    2014-10-01

    A new variational finite element method is developed for nonlinear free surface gravity water waves using the potential flow approximation. This method also handles waves generated by a wave maker. Its formulation stems from Miles' variational principle for water waves together with a finite element discretization that is continuous in space and discontinuous in time. One novel feature of this variational finite element approach is that the free surface evolution is variationally dependent on the mesh deformation vis-à-vis the mesh deformation being geometrically dependent on free surface evolution. Another key feature is the use of a variational (dis)continuous Galerkin finite element discretization in time. Moreover, in the absence of a wave maker, it is shown to be equivalent to the second order symplectic Störmer-Verlet time stepping scheme for the free-surface degrees of freedom. These key features add to the stability of the numerical method. Finally, the resulting numerical scheme is verified against nonlinear analytical solutions with long time simulations and validated against experimental measurements of driven wave solutions in a wave basin of the Maritime Research Institute Netherlands.

  5. Longitudinal surface cracks on continuous casting slabs of P and Cu containing container steel

    Institute of Scientific and Technical Information of China (English)

    Xinhua Wang; Zhiyuan Zhu; Li Zhang; Guodong Xu

    2003-01-01

    The fact that the amount of the mold flux components differs at different locations on the cracking surface indicates that the longitudinal surface cracks are initially formed in the mold and are enlarged in the secondary cooling zone. Based on the hot ductility measurement of two typical container used steels, it is known that the steels are in severe embrittlement state in the temperature range of 825-775℃. By means of increasing Cr/Ni plating thickness on the upper part of the mold, reducing mold heat flux, adopting new secondary cooling pattern, etc., the occurrence of the surface longitudinal cracks on the steel CC (continuous casting) slabs has been significantly reduced.

  6. Hamilton--Jacobi theory for continuation of magnetic field across a toroidal surface supporting a plasma pressure discontinuity

    CERN Document Server

    McGann, M; Dewar, R L; von Nessi, G

    2010-01-01

    The vanishing of the divergence of the total stress tensor (magnetic plus kinetic) in a neighborhood of an equilibrium plasma containing a toroidal surface of discontinuity gives boundary and jump conditions that strongly constrain allowable continuations of the magnetic field across the surface. The boundary conditions allow the magnetic fields on either side of the discontinuity surface to be described by surface magnetic potentials, reducing the continuation problem to that of solving a Hamilton--Jacobi equation. The characteristics of this equation obey Hamiltonian equations of motion, and a necessary condition for the existence of a continued field across a general toroidal surface is that there exist invariant tori in the phase space of this Hamiltonian system. It is argued from the Birkhoff theorem that existence of such an invariant torus is also, in general, sufficient for continuation to be possible. An important corollary is that the rotational transform of the continued field on a surface of disco...

  7. A novel method about online monitoring surface shape of optical elements in continuous polishing

    Science.gov (United States)

    Yin, Jin; Zhu, Jianqiang; Jiao, Xiang; Wu, Yongzhong

    2016-10-01

    In conventional continuous polishing process, the surface shape of work-piece was measured by an optical plane template after being placed in such environment with constant temperature for 1 to 2 hours. During this period, uncertain influence may occur on the polishing pad due to the change of system state. Meanwhile, the regular off-line testing may cause re-processing. In this paper, a new method about on-line monitoring surface shape of optical elements is proposed by the theory of run sphere, and the change in curvature radius of the work-piece which lead to its radial tilt angle change. The change in work-piece surface shape indirectly obtain by the correction plate small angle with respect to the horizontal, and the angle were detected on line by the high-precision goniometer with the resolution 0.04 ''. According to theoretical calculations, the diameter of 200mm precision work-piece PV value up to 0.02λ (λ = 632.8nm). The fused quartz glass was measured by above method. The test results showed that the surface accuracy and processing efficiency were significantly promoted, and also improving the controllability of surface shape of work-piece based on this method.

  8. Continuous fabrication of nanostructure arrays for flexible surface enhanced Raman scattering substrate

    Science.gov (United States)

    Zhang, Chengpeng; Yi, Peiyun; Peng, Linfa; Lai, Xinmin; Chen, Jie; Huang, Meizhen; Ni, Jun

    2017-01-01

    Surface-enhanced Raman spectroscopy (SERS) has been a powerful tool for applications including single molecule detection, analytical chemistry, electrochemistry, medical diagnostics and bio-sensing. Especially, flexible SERS substrates are highly desirable for daily-life applications, such as real-time and in situ Raman detection of chemical and biological targets, which can be used onto irregular surfaces. However, it is still a major challenge to fabricate the flexible SERS substrate on large-area substrates using a facile and cost-effective technique. The roll-to-roll ultraviolet nanoimprint lithography (R2R UV-NIL) technique provides a solution for the continuous fabrication of flexible SERS substrate due to its high-speed, large-area, high-resolution and high-throughput. In this paper, we presented a facile and cost-effective method to fabricate flexible SERS substrate including the fabrication of polymer nanostructure arrays and the metallization of the polymer nanostructure arrays. The polymer nanostructure arrays were obtained by using R2R UV-NIL technique and anodic aluminum oxide (AAO) mold. The functional SERS substrates were then obtained with Au sputtering on the surface of the polymer nanostructure arrays. The obtained SERS substrates exhibit excellent SERS and flexibility performance. This research can provide a beneficial direction for the continuous production of the flexible SERS substrates. PMID:28051175

  9. Continuous fabrication of nanostructure arrays for flexible surface enhanced Raman scattering substrate

    Science.gov (United States)

    Zhang, Chengpeng; Yi, Peiyun; Peng, Linfa; Lai, Xinmin; Chen, Jie; Huang, Meizhen; Ni, Jun

    2017-01-01

    Surface-enhanced Raman spectroscopy (SERS) has been a powerful tool for applications including single molecule detection, analytical chemistry, electrochemistry, medical diagnostics and bio-sensing. Especially, flexible SERS substrates are highly desirable for daily-life applications, such as real-time and in situ Raman detection of chemical and biological targets, which can be used onto irregular surfaces. However, it is still a major challenge to fabricate the flexible SERS substrate on large-area substrates using a facile and cost-effective technique. The roll-to-roll ultraviolet nanoimprint lithography (R2R UV-NIL) technique provides a solution for the continuous fabrication of flexible SERS substrate due to its high-speed, large-area, high-resolution and high-throughput. In this paper, we presented a facile and cost-effective method to fabricate flexible SERS substrate including the fabrication of polymer nanostructure arrays and the metallization of the polymer nanostructure arrays. The polymer nanostructure arrays were obtained by using R2R UV-NIL technique and anodic aluminum oxide (AAO) mold. The functional SERS substrates were then obtained with Au sputtering on the surface of the polymer nanostructure arrays. The obtained SERS substrates exhibit excellent SERS and flexibility performance. This research can provide a beneficial direction for the continuous production of the flexible SERS substrates.

  10. Continuous Multiscale Entanglement Renormalization Ansatz as Holographic Surface-State Correspondence

    Science.gov (United States)

    Miyaji, Masamichi; Numasawa, Tokiro; Shiba, Noburo; Takayanagi, Tadashi; Watanabe, Kento

    2015-10-01

    We present how the surface-state correspondence, conjectured by Miyaji and Takayanagi, works in the setup of AdS3/CFT2 by generalizing the formulation of a continuous multiscale entanglement renormalization group ansatz. The boundary states in conformal field theories play a crucial role in our formulation and the bulk diffeomorphism is naturally taken into account. We give an identification of bulk local operators which reproduces correct scalar field solutions on AdS3 and bulk scalar propagators. We also calculate the information metric for a locally excited state and show that it reproduces the time slice of AdS3.

  11. Continuous Multiscale Entanglement Renormalization Ansatz as Holographic Surface-State Correspondence.

    Science.gov (United States)

    Miyaji, Masamichi; Numasawa, Tokiro; Shiba, Noburo; Takayanagi, Tadashi; Watanabe, Kento

    2015-10-23

    We present how the surface-state correspondence, conjectured by Miyaji and Takayanagi, works in the setup of AdS(3)/CFT(2) by generalizing the formulation of a continuous multiscale entanglement renormalization group ansatz. The boundary states in conformal field theories play a crucial role in our formulation and the bulk diffeomorphism is naturally taken into account. We give an identification of bulk local operators which reproduces correct scalar field solutions on AdS(3) and bulk scalar propagators. We also calculate the information metric for a locally excited state and show that it reproduces the time slice of AdS(3).

  12. Short term forecasting of surface layer wind speed using a continuous cascade model

    CERN Document Server

    Baile, Rachel; Poggi, Philippe

    2010-01-01

    This paper describes a statistical method for short-term forecasting of surface layer wind velocity amplitude relying on the notion of continuous cascades. Inspired by recent empirical findings that suggest the existence of some cascading process in the mesoscale range, we consider that wind speed can be described by a seasonal component and a fluctuating part represented by a "multifractal noise" associated with a random cascade. Performances of our model are tested on hourly wind speed series gathered at various locations in Corsica (France) and Netherlands. The obtained results show a systematic improvement of the prediction as compared to reference models like persistence or Artificial Neural Networks.

  13. A 45-element continuous facesheet surface micromachined deformable mirror for optical aberration correction

    Directory of Open Access Journals (Sweden)

    Weimin Wang

    2014-02-01

    Full Text Available A 45-element continuous facesheet surface micromachined deformable mirror (DM is presented and is fabricated using the PolyMUMPs multi-user micro-electro-mechanical system processes. The effects of the structural parameters on the characteristics of the DM, such as its stroke, frequency and actuator coupling, are analyzed. In addition, the DM design has also been verified through experimental testing. This DM prototype has a surface figure of 0.5 μm and a fill factor of 95%. The DM can provide a 0.6 μm stroke with 5.9% actuator coupling. A static aberration correction based on this DM is also demonstrated, which acts as a reference for the potential adaptive optics (AO applications of the device.

  14. Highly Nonlinear Luminescence Induced by Gold Nanoparticles on Glass Surfaces with Continuous-Wave Laser Illumination

    CERN Document Server

    Wu, Yong; Toro, Ligia; Stefani, Enrico

    2015-01-01

    We report on highly nonlinear luminescence being observed from individual spherical gold nanoparticles immobilized on a borosilicate glass surface and illuminated by continuous-wave (CW) lasers with relatively low power. The nonlinear luminescence shows optical super-resolution beyond the diffraction limit in three dimensions compared to the scatting of the excitation laser light. The luminescence intensity from most nanoparticles is proportional to the 5th--7th power of the excitation laser power and has wide excitation and emission spectra across the visible wavelength range. Strong nonlinear luminescence is only observed near the glass surface. High optical nonlinearity excited by low CW laser power is related to a long-lived dark state of the gold nanoparticles, where the excitation light is strongly absorbed. This phenomenon has potential biological applications in super-resolution and deep tissue imaging.

  15. Preservation of the Pt(100) surface reconstruction after growth of a continuous layer of graphene

    DEFF Research Database (Denmark)

    Nilsson, Louis; Andersen, Mie; Bjerre, Jacob;

    2012-01-01

    Scanning tunneling microscopy shows that a layer of graphene can be grown on the hex-reconstructed Pt(100) surface and that the reconstruction is preserved after growth. A continuous sheet of graphene can be grown across domain boundaries and step edges without loss of periodicity or change...... to accommodation of edge dislocations. The defect formation energy and the induced buckling of the graphene have been characterized by DFT calculations....... in direction. Density functional theory calculations on a simple model system support the observation that the graphene can have different rotation angles relative to the hex-reconstructed Pt surface. The graphene sheet direction can be changed by incorporating pentagon-heptagon defects giving rise...

  16. Pseudo-random noise-continuous-wave laser radar for surface and cloud measurements

    Science.gov (United States)

    Matthey, Renaud; Mitev, Valentin

    2005-03-01

    Laser radar (lidar) application may require an instrument with compact size, long life of the components, low consumption and eye-safety. One possibility to achieve these features is to use a continuous-wave (cw) diode laser as lidar transmitter. A practical way to perform range-resolved measurements with a cw laser diode is the pseudo-random noise (PRN) modulation. This paper presents a compact PRN-cw lidar, using a 370-mW cw diode laser and an APD as detector. Daytime measurements of cloud base and topographic surface are demonstrated with the PRN-cw lidar technique, where the range detection exceeds 2 km. The detection of the topographic surface is performed with integration time of some tens of milliseconds during daytime and some tens of microseconds during night-time.

  17. Circadian rhythms in human muscular efficiency: continuous physical exercise versus continuous rest. A crossover study.

    Science.gov (United States)

    Callard, D; Davenne, D; Gauthier, A; Lagarde, D; Van Hoecke, J

    2000-09-01

    This study deals with the influence of time of day on neuromuscular efficiency in competitive cyclists during continuous exercise versus continuous rest. Knee extension torque was measured in ultradistance cyclists over a 24h period (13:00 to 13:00 the next day) in the laboratory. The subjects were requested to maintain a constant speed (set at 70% of their maximal aerobic speed obtained during a preliminary test) on their own bicycles, which were equipped with cyclosimulators. Every 4h, torque developed and myoelectric activity were estimated during maximal isometric voluntary contractions of knee extensors using an isokinetic dynamometer. Mesenteric temperature was monitored by telemetry. The same measures were also recorded while the subjects were resting awake until 13:00 the next day. During activity, torque changed within the 24h period (p rhythm was observed in knee extensor torque (p rhythms were correlated significantly. Although at rest the diurnal rhythm followed muscular activity (i.e., neurophysiological factors), during exercise, this rhythm was thought to stem more from fluctuations in the contractile state of muscle.

  18. Continuous measurements of water surface height and width along a 6.5km river reach for discharge algorithm development

    Science.gov (United States)

    Tuozzolo, S.; Durand, M. T.; Pavelsky, T.; Pentecost, J.

    2015-12-01

    The upcoming Surface Water and Ocean Topography (SWOT) satellite will provide measurements of river width and water surface elevation and slope along continuous swaths of world rivers. Understanding water surface slope and width dynamics in river reaches is important for both developing and validating discharge algorithms to be used on future SWOT data. We collected water surface elevation and river width data along a 6.5km stretch of the Olentangy River in Columbus, Ohio from October to December 2014. Continuous measurements of water surface height were supplemented with periodical river width measurements at twenty sites along the study reach. The water surface slope of the entire reach ranged from during 41.58 cm/km at baseflow to 45.31 cm/km after a storm event. The study reach was also broken into sub-reaches roughly 1km in length to study smaller scale slope dynamics. The furthest upstream sub-reaches are characterized by free-flowing riffle-pool sequences, while the furthest downstream sub-reaches were directly affected by two low-head dams. In the sub-reaches immediately upstream of each dam, baseflow slope is as low as 2 cm/km, while the furthest upstream free-flowing sub-reach has a baseflow slope of 100 cm/km. During high flow events the backwater effect of the dams was observed to propagate upstream: sub-reaches impounded by the dams had increased water surface slopes, while free flowing sub-reaches had decreased water surface slopes. During the largest observed flow event, a stage change of 0.40 m affected sub-reach slopes by as much as 30 cm/km. Further analysis will examine height-width relationships within the study reach and relate cross-sectional flow area to river stage. These relationships can be used in conjunction with slope data to estimate discharge using a modified Manning's equation, and are a core component of discharge algorithms being developed for the SWOT mission.

  19. Continued Use of a Chinese Online Portal: An Empirical Study

    Science.gov (United States)

    Shih, Hung-Pin

    2008-01-01

    The evolution of the internet has made online portals a popular means of surfing the internet. In internet commerce, understanding the post-adoption behaviour of users of online portals can help enterprises to attract new users and retain existing customers. For predicting continued use intentions, this empirical study focused on applying and…

  20. Continental-scale water fluxes from continuous GPS observations of Earth surface loading

    Science.gov (United States)

    Borsa, A. A.; Agnew, D. C.; Cayan, D. R.

    2015-12-01

    After more than a decade of observing annual oscillations of Earth's surface from seasonal snow and water loading, continuous GPS is now being used to model time-varying terrestrial water fluxes on the local and regional scale. Although the largest signal is typically due to the seasonal hydrological cycle, GPS can also measure subtle surface deformation caused by sustained wet and dry periods, and to estimate the spatial distribution of the underlying terrestrial water storage changes. The next frontier is expanding this analysis to the continental scale and paving the way for incorporating GPS models into the National Climate Assessment and into the observational infrastructure for national water resource management. This will require reconciling GPS observations with predictions from hydrological models and with remote sensing observations from a suite of satellite instruments (e.g. GRACE, SMAP, SWOT). The elastic Earth response which transforms surface loads into vertical and horizontal displacements is also responsible for the contamination of loading observations by tectonic and anthropogenic transients, and we discuss these and other challenges to this new application of GPS.

  1. Study on a continuous heat integrated distillation column

    Energy Technology Data Exchange (ETDEWEB)

    Glenchur, T.; Govind, R.

    1987-12-01

    A novel continuous heat integrated distillation column called a concentric column has been studied using computer simulation. It is shown that a concentric column is a novel implementation of a thermodynamically reversible distillation column and has a lower energy loss than an ordinary distillation column. Their studies show that a concentric column has reduced column height, since the stripping section is configured concentrically around the rectifying section, and uses less utilities than a conventional column.

  2. MHD flow and heat transfer from continuous surface in uniform free stream of non-Newtonian fluid

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An analysis is carried out to study the steady flow and heat transfer characteristics from a continuous flat surface moving in a parallel free stream of an electrically conducting non-Newtonian viscoelastic fluid. The flow is subjected to a transverse uniform magnetic field. The constitutive equation of the fluid is modeled by that for a second grade fluid. Numerical results are obtained for the distribution of velocity and temperature profiles. The effects of various physical parameters like viscoelastic parameter, magnetic parameter and Prandtl number on various momentum and heat transfer characteristics are discussed in detail and shown graphically.

  3. [Comparative study on software demodulation for continuous wave and quasi-continuous wave wavelength modulation spectroscopy].

    Science.gov (United States)

    Shao, Xin; Liu, Fu-Gui; Chen, Wen-Liang

    2013-12-01

    According to the modulation signal applied on laser diodes, wavelength modulation spectroscopy (WMS) can be divided into continuous wave (CW) WMS and quasi-continuous wave (QCW) WMS. In order to deeply compare CW-WMS and QCW-WMS, we used a specific software-realized lock-in amplifier for continuous and quasi-continuous modulation signal demodulation. The invalid signal in quasi-continuous modulation spectrum was filtered off, and then the effective detection signal was demodulated to obtain the second harmonic signal (WMS-2f). It was compared with the 2f signal demodulated continuous laser modulation spectrum with software. The results show that while the same system parameters are set, the signal-to-noise of the quasi-continuous modulation spectrum is 5% higher than the continuous modulation spectrum with software demodulation measurements, and the detection limit is 11.3% lower. And without the invalid signal in quasi-continuous modulation spectrum, the standard WMS-2f signal can be demodulated, which has potential to be used for the investigation of gas absorption profile. This work has provided accurate reference for selections of the laser modulation spectroscopy.

  4. Continuous neurophatic orofacial pain: A retrospective study of 23 cases.

    Science.gov (United States)

    Sotorra-Figuerola, Dídac; Sánchez-Torres, Alba; Valmaseda-Castellón, Eduard; Gay-Escoda, Cosme

    2016-04-01

    To determine the clinical characteristics of Continuous Neuropathic Orofacial Pain in patients that suffer Persistent Idiopathic Facial Pain (PIFP), Painful Post-Traumatic Trigeminal Neuropathy (PPTTN) or Burning Mouth Syndrome (BMS) and to describe their treatment. A retrospective observational study was made, reviewing the clinical history of the patients diagnosed with Continuous Neuropathic Orofacial Pain between 2004 and 2011 at the Orofacial Pain Unit of the Master of Oral Surgery and Implantology of the University of Barcelona and at the Orofacial Pain Unit of the Teknon Medical Center of Barcelona. The average age of the patients with Continuous Neuropathic Orofacial Pain was 54.5, with a clear female predominance (86.9%, n=20). Of all patients, 60.9% (n=14) were suffering a PIFP, 21.7% (n=5) had a BMS and 17.4% (n=4) were presenting a PPTTN. The pain quality described by the patients with Continuous Neuropathic Orofacial Pain was oppressive (43.47%, n=10), widely represented by patients with PIFP, and burning (39.13%, n=9) being the only quality that described patients with BMS. The treatment carried out with the patients was only pharmacologic. The most used drugs for the treatment of PIFP and PPTTN were clonazepam (50%, n=9) and amitriptyline (44.44%, n=8). However, a 55.5% (n=10) of the patients with PIFP or PPTTN required the association of two or more drugs for a correct pain control. All the patients with BMS responded satisfactorily to clonazepam. Continuous Neuropathic Orofacial Pain is a little known condition among the general population, physicians and dentists. This favors a late diagnosis and inaccurate treatments which entail unnecessary suffering. It is important to inform both the general population and health professionals concerning this painful condition. Continuous neuropathic orofacial pain, persistent idiopathic facial pain, painful post-traumatic trigeminal neuropathy, burning mouth syndrome, atypical odontalgia.

  5. Continuity in Multi-Device Interaction: An Online Study

    DEFF Research Database (Denmark)

    Raptis, Dimitrios; Kjeldskov, Jesper; Skov, Mikael

    2016-01-01

    Techniques for multi-device interactions are finding their way into commercial products. This means that people are now exposed to possibilities of interacting with and across their devices, and this presents a valuable opportunity for studying their uptake and use in real life. In this paper we...... investigate and discuss the emerging multi-device interaction concept of “continuity”, which allow an activity to begin on one device and continue on another. We present a study of the challenges people have experienced in the use of a specific new product offering such functionality, namely Apple......’s Continuity. The study was done through surveying 3361 posts from technology web sites, discussion forums, and blogs, with a qualitative analysis of 1603 posts. Our findings present challenges in six themes of privacy, appropriation, customization, awareness, exclusion, and troubleshooting in relation...

  6. Continuous surface force based lattice Boltzmann equation method for simulating thermocapillary flow

    CERN Document Server

    Zheng, Lin; Zhai, Qinglan

    2014-01-01

    In this paper, we extend a lattice Boltzmann equation (LBE) with continuous surface fore (CSF) to simulate thermocapillary flows. The model is designed on our previous CSF LBE for athermal two phase flow, in which the interfacial tension forces and the Marangoni stresses as the results of the interface interactions between different phases are described by a conception of CSF. In this model, the sharp interfaces between different phases are separated by a narrow transition layers, and the kinetics and morphology evolution of phase separation would be characterized by an order parameter visa Cahn-Hilliard equation which is solved in the frame work of LBE. The scalar convection-diffusion equation for temperature field is also solved by thermal LBE. The models are validated by thermal two layered Poiseuille flow, and a two superimposed planar fluids at negligibly small Reynolds and Marangoni numbers for the thermocapillary driven convection, which have analytical solutions for the velocity and temperature. Then ...

  7. Continuous-wave optically pumped green perovskite vertical-cavity surface-emitter

    KAUST Repository

    Alias, Mohd Sharizal

    2017-09-11

    We report an optically pumped green perovskite vertical-cavity surface-emitter operating in continuous-wave (CW) with a power density threshold of ∼89  kW/cm2. The device has an active region of CH3NH3PbBr3 embedded in a dielectric microcavity; this feat was achieved with a combination of optimal spectral alignment of the optical cavity modes with the perovskite optical gain, an adequate -factor of the microcavity, adequate thermal stability, and improved material quality with a smooth, passivated, and annealed thin active layer. Our results signify a way towards efficient CW perovskite emitter operation and electrical injection using low-cost fabrication methods for addressing monolithic optoelectronic integration and lasing in the green gap.

  8. Continuous-wave optically pumped green perovskite vertical-cavity surface-emitter

    KAUST Repository

    Alias, Mohd Sharizal

    2017-09-11

    We report an optically pumped green perovskite vertical-cavity surface-emitter operating in continuous-wave (CW) with a power density threshold of ~89 kW/cm. The device has an active region of CHNHPbBr embedded in a dielectric microcavity; this feat was achieved with a combination of optimal spectral alignment of the optical cavity modes with the perovskite optical gain, an adequate Q-factor of the microcavity, adequate thermal stability, and improved material quality with a smooth, passivated, and annealed thin active layer. Our results signify a way towards efficient CW perovskite emitter operation and electrical injection using low-cost fabrication methods for addressing monolithic optoelectronic integration and lasing in the green gap.

  9. Microscopic degradation mechanism of polyimide film caused by surface discharge under bipolar continuous square impulse voltage

    Science.gov (United States)

    Luo, Yang; Wu, Guang-Ning; Liu, Ji-Wu; Peng, Jia; Gao, Guo-Qiang; Zhu, Guang-Ya; Wang, Peng; Cao, Kai-Jiang

    2014-02-01

    Polyimide (PI) film is an important type of insulating material used in inverter-fed motors. Partial discharge (PD) under a sequence of high-frequency square impulses is one of the key factors that lead to premature failures in insulation systems of inverter-fed motors. In order to explore the damage mechanism of PI film caused by discharge, an aging system of surface discharge under bipolar continuous square impulse voltage (BCSIV) is designed based on the ASTM 2275 01 standard and the electrical aging tests of PI film samples are performed above the partial discharge inception voltage (PDIV). The chemical bonds of PI polymer chains are analyzed through Fourier transform infrared spectroscopy (FTIR) and the dielectric properties of unaged and aged PI samples are investigated by LCR testers HIOKI 3532-50. Finally, the micro-morphology and micro-structure changes of PI film samples are observed through scanning electron microscopy (SEM). The results show that the physical and chemical effects of discharge cut off the chemical bonds of PI polymer chains. The fractures of ether bond (C—O—C) and imide ring (C—N—C) on the backbone of a PI polymer chain leads to the decrease of molecular weight, which results in the degradation of PI polymers and the generation of new chemical groups and materials, like carboxylic acid, ketone, aldehydes, etc. The variation of microscopic structure of PI polymers can change the orientation ability of polarizable units when the samples are under an AC electric field, which would cause the dielectric constant ɛ to increase and dielectric loss tan δ to decrease. The SEM images show that the degradation path of PI film is initiated from the surface and then gradually extends to the interior with continuous aging. The injection charge could result in the PI macromolecular chain degradation and increase the trap density in the PI polymer bulk.

  10. Continuous order-disorder phase transition (2 x 2){yields}(1 x 1) on the (0001)AlN surface

    Energy Technology Data Exchange (ETDEWEB)

    Mansurov, V.G.; Galitsyn, Yu.G.; Nikitin, A.Yu.; Kolosovsky, E.A.; Zhuravlev, K.S. [Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, pr. ak. Lavrent' eva 13, Novosibirsk 630090 (Russian Federation); Osvath, Z.; Dobos, L.; Horvath, Z.E.; Pecz, B. [Research Institute for Technical Physics and Materials Science, Hungarian Academy of Sciences, P.O. Box 49, 1525 Budapest (Hungary)

    2007-06-15

    Smooth (0001)AlN surface on a (0001) sapphire substrate was prepared by ammonia Molecular Beam Epitaxy. A continuous (2 x 2){yields}(1 x 1) reconstruction phase transition on the (0001)AlN surface under ammonia flux was experimentally investigated by RHEED. The intensity of a fractional (0 1/2) streak was studied as a function of the sample temperature under different ammonia fluxes. The temperature of the transition increases with increasing of the ammonia flux (an effective activation energy is about 1.3 eV). The phase transition is described in the frame of the Bethe-Peierls approximation. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Direct writing of continuous and discontinuous sub-wavelength periodic surface structures on single-crystalline silicon using femtosecond laser

    Energy Technology Data Exchange (ETDEWEB)

    Kuladeep, Rajamudili; Sahoo, Chakradhar; Narayana Rao, Desai, E-mail: dnrsp@uohyd.ernet.in, E-mail: dnr-laserlab@yahoo.com [School of Physics, University of Hyderabad, Hyderabad 500046 (India)

    2014-06-02

    Laser-induced ripples or uniform arrays of continuous near sub-wavelength or discontinuous deep sub-wavelength structures are formed on single-crystalline silicon (Si) by femtosecond (fs) laser direct writing technique. Laser irradiation was performed on Si wafers at normal incidence in air and by immersing them in dimethyl sulfoxide using linearly polarized Ti:sapphire fs laser pulses of ∼110 fs pulse duration and ∼800 nm wavelength. Morphology studies of laser written surfaces reveal that sub-wavelength features are oriented perpendicular to laser polarization, while their morphology and spatial periodicity depend on the surrounding dielectric medium. The formation mechanism of the sub-wavelength features is explained by interference of incident laser with surface plasmon polaritons. This work proves the feasibility of fs laser direct writing technique for the fabrication of sub-wavelength features, which could help in fabrication of advanced electro-optic devices.

  12. Physics-Based Continuous Simulation of Long-Term Near-Surface Hydrologic Response for the Coos Bay Experimental Catchment

    Science.gov (United States)

    Ebel, B. A.; Loague, K.; Montgomery, D. R.; Dietrich, W. E.

    2007-12-01

    The study reported here employed the physics-based InHM to simulate continuous hydrologic response from 1990 through 1996 for the Coos Bay (CB1) experimental catchment. InHM dynamically simulates 3D variably- saturated subsurface flow using Richards equation and 2D surface and open channel flow using the diffusion- wave approximation to the depth-integrated shallow-water equations. The uniqueness of the boundary-value problem (BVP) used in a previous study to successfully simulate three sprinkling experiments was assessed, via model performance evaluation against piezometric and discharge data, for 33 events extracted from the seven- year continuous record. The simulations conducted in this effort suggest the potential for interaction between the deeper water table and near-surface hydrologic response, which is in agreement with the detailed field observations made during the CB1 sprinkling experiments. The InHM simulations could not adequately reproduce the observed pore-water pressures, suggesting that detailed characterization of the locations and connectivities of bedrock fractures would be necessary to simulate distributed hydrologic response at locations where bedrock fracture flow is important. The results from this study suggest that uniqueness is a problem for physics-based models when employing a BVP used successfully for smaller magnitude storms to simulate larger storms. The long-term simulations conducted here, combined with previous event-based hydrologic- response simulations and field-based observations, highlight the challenges in characterizing / simulating fractured bedrock flow at small catchments like CB1.

  13. Continuing Studies on Lead/Scintillating Fibres Calorimetry (LFC)

    CERN Multimedia

    2002-01-01

    Starting from the results obtained in the framework of the LAA Project~2B, we propose a continuation of the R&D on lead/scintillating fibres calorimetry (``spaghetti calorimetry''), including further tests on the old calorimeter prototypes and the construction and testing of new prototypes. The main results we pursue concern the performances of a projective calorimeter built with new, cheaper, techniques and the radiation hardness of the scintillating fibres, the optimization of a preshower detector system is also studied.

  14. Land Movement Studies at Tide Gauge using Continuous GPS Technique

    Science.gov (United States)

    Niemnil, Sommart

    From land movement studies using Continuous GPS (CGPS) Technique at tide gauge station in Phrachunlachomklao Fort, Samutprakan province, Thailand results that this station clearly subsides 2 - 3 mm./yr which is higher than CGPS Permanent station at Chulalongkorn University in Bangkok. The preliminary horizontal land motion in north, east direction and vertical movement results are -0.28 ± 3.63, 27.87 ± 4.35 and -27.89 ± 5.59, mm./yr respectively.

  15. Continuous surface charge polarizable continuum models of solvation. I. General formalism.

    Science.gov (United States)

    Scalmani, Giovanni; Frisch, Michael J

    2010-03-21

    Continuum solvation models are appealing because of the simplified yet accurate description they provide of the solvent effect on a solute, described either by quantum mechanical or classical methods. The polarizable continuum model (PCM) family of solvation models is among the most widely used, although their application has been hampered by discontinuities and singularities arising from the discretization of the integral equations at the solute-solvent interface. In this contribution we introduce a continuous surface charge (CSC) approach that leads to a smooth and robust formalism for the PCM models. We start from the scheme proposed over ten years ago by York and Karplus and we generalize it in various ways, including the extension to analytic second derivatives with respect to atomic positions. We propose an optimal discrete representation of the integral operators required for the determination of the apparent surface charge. We achieve a clear separation between "model" and "cavity" which, together with simple generalizations of modern integral codes, is all that is required for an extensible and efficient implementation of the PCM models. Following this approach we are now able to introduce solvent effects on energies, structures, and vibrational frequencies (analytical first and second derivatives with respect to atomic coordinates), magnetic properties (derivatives with respect of magnetic field using GIAOs), and in the calculation more complex properties like frequency-dependent Raman activities, vibrational circular dichroism, and Raman optical activity.

  16. The Einstein-Vlasov system with cosmological constant in a surface-symmetric cosmological model local existence and continuation criteria

    CERN Document Server

    Tchapnda, S B; Tchapnda, Sophonie Blaise; Noutchegueme, Norbert

    2003-01-01

    The Einstein-Vlasov system describes a self-gravitating, collisionless gas within the framework of general relativity. We investigate the initial value problem in a cosmological setting with surface symmetry and a non-zero cosmological constant and prove local existence and continuation criteria in both time directions. The continuation criterion says that as long as the maximum velocity remains bounded and the lapse function remains bounded then the solution can be continued. This applies to either time direction.

  17. Perturbative study on the analytic continuation for generalized gravitational entropy

    Science.gov (United States)

    Prudenziati, Andrea

    2015-05-01

    We study the analytic continuation used by Lewkowycz and Maldacena to prove the Ryu-Takayanagi formula for entanglement entropy, which is the holographic dual of the trace of the β -power of the Euclidean time evolution operator when β ∈R . This will be done perturbatively using a weakly time dependent Hamiltonian, corresponding to a small shift of the dual static background. The perturbation will be set to either satisfy the Lewkowycz-Maldacena proposal or a different analytic continuation, depending on its periodicity conditions. The two choices will be tested by computing the associated entropies and compared to the Ryu-Takayanagi formula. To our surprise we discover that, at first order, they both correctly reproduce the associated entanglement entropy. Furthermore in both cases we find unexpected divergent contributions that we have to discard in order to fit the minimal area computation, and an additional requirement on the β dependence on the metric.

  18. Research on improved design of airfoil profiles based on the continuity of airfoil surface curvature of wind turbines

    DEFF Research Database (Denmark)

    Chen, Jin; Cheng, Jiangtao; Shen, Wenzhong

    2013-01-01

    Aerodynamic of airfoil performance is closely related to the continuity of its surface curvature, and airfoil profiles with a better aerodynamic performance plays an important role in the design of wind turbine. The surface curvature distribution along the chord direction and pressure distributio...

  19. Laser surface processing and model studies

    CERN Document Server

    Yilbas, Bekir Sami

    2013-01-01

    This book introduces model studies associated with laser surface processing such as conduction limited heating, surface re-melting, Marangoni flow and its effects on the temperature field, re-melting of multi-layered surfaces, laser shock processing, and practical applications. The book provides insight into the physical processes involved with laser surface heating and phase change in laser irradiated region. It is written for engineers and researchers working on laser surface engineering.

  20. Monitoring the Continuous Surface Motion of Glaciers by Low-Cost GNSS Receivers

    Science.gov (United States)

    Völksen, Christof; Mayer, Christoph

    2015-04-01

    framework which is placed on the surface of the glacier. Here we observed continuously the melting process of the glacier surface during the ablation season 2014, which reduced the glacier elevation at this location by 2 m. A similar experiment was also applied on the glacier Mýrdalsjökull in Iceland. Even though the experiment did not last over the entire winter we could observe a significant difference in the motion of the glacier. During the summer the resulting horizontal velocity was almost 22 m/a, while the average over the entire year was estimated to 13 m/a.

  1. Surface Wave Tomography with Spatially Varying Smoothing Based on Continuous Model Regionalization

    Science.gov (United States)

    Liu, Chuanming; Yao, Huajian

    2017-03-01

    Surface wave tomography based on continuous regionalization of model parameters is widely used to invert for 2-D phase or group velocity maps. An inevitable problem is that the distribution of ray paths is far from homogeneous due to the spatially uneven distribution of stations and seismic events, which often affects the spatial resolution of the tomographic model. We present an improved tomographic method with a spatially varying smoothing scheme that is based on the continuous regionalization approach. The smoothness of the inverted model is constrained by the Gaussian a priori model covariance function with spatially varying correlation lengths based on ray path density. In addition, a two-step inversion procedure is used to suppress the effects of data outliers on tomographic models. Both synthetic and real data are used to evaluate this newly developed tomographic algorithm. In the synthetic tests, when the contrived model has different scales of anomalies but with uneven ray path distribution, we compare the performance of our spatially varying smoothing method with the traditional inversion method, and show that the new method is capable of improving the recovery in regions of dense ray sampling. For real data applications, the resulting phase velocity maps of Rayleigh waves in SE Tibet produced using the spatially varying smoothing method show similar features to the results with the traditional method. However, the new results contain more detailed structures and appears to better resolve the amplitude of anomalies. From both synthetic and real data tests we demonstrate that our new approach is useful to achieve spatially varying resolution when used in regions with heterogeneous ray path distribution.

  2. An efficient analytical decomposition and numerical procedure for boundary layer flow on a continuous stretching surface

    Institute of Scientific and Technical Information of China (English)

    Xuehui Chen; Liancun Zheng; Xinxin Zhang

    2006-01-01

    An efficient Adomian analytical decomposition technique for studying the momentum and heat boundary layer equations with exponentially stretching surface conditions was presented and an approximate analytical solution was obtained, which can be represented in terms of a rapid convergent power series with elegantly computable terms. The reliability and efficiency of the approximate solution were verified using numerical solutions in the literature. The approximate solution can be successfully applied to provide the values of skin friction and the temperature gradient coefficient.

  3. Capacitor film surface assessment studies

    Science.gov (United States)

    Galperin, I.; White, W.

    1985-02-01

    In the present investigation of the optical surface of the three widely used, biaxially oriented capacitor films, polypropylene, polyvinylidene fluoride, and polyester, with attention to film surface defects and thickness variation, the defects and their rate of occurrence proved traceable in terms of polymer structure, chemical grouping, and fabrication processing. Film thickness variation was small, yet differed for each film type. Film breakdown voltages have been determined, and alternative causes for the voltage values obtained are proposed. A reciprocal relation is noted between the film breakdown voltage and the dielectric constant.

  4. Using continuous measurements of near-surface atmospheric water vapor isotopes to document snow-air interactions

    Science.gov (United States)

    Steen-Larsen, Hans Christian; Masson-Delmotte, Valerie; Hirabayashi, Motohiro; Winkler, Renato; Satow, Kazuhide; Prie, Frederic; Bayou, Nicolas; Brun, Eric; Cuffey, Kurt; Dahl-Jensen, Dorthe; Dumont, Marie; Guillevic, Myriam; Kipfstuhl, Sepp; Landais, Amaelle; Popp, Trevor; Risi, Camille; Steffen, Konrad; Stenni, Barbara; Sveinbjornsdottir, Arny

    2014-05-01

    recrystallization processes associated with temperature gradients near the snow surface. Our findings have implications for ice core data interpretation and model-data comparisons, and call for further process studies. Reference: Steen-Larsen et al.: What controls the isotopic composition of Greenland surface snow?, Climate of the Past Discussions, 9, 6035-6076, 2013 http://www.clim-past-discuss.net/9/6035/2013/cpd-9-6035-2013.html Steen-Larsen et al.: Continuous monitoring of summer surface water vapor isotopic composition above the Greenland Ice Sheet, Atmos. Chem. Phys., 13, 4815-4828, 2013 http://www.atmos-chem-phys.net/13/4815/2013/acp-13-4815-2013.html

  5. Flow and thermal behavior of the top surface flux/powder layers in continuous casting molds

    Science.gov (United States)

    McDavid, R. M.; Thomas, B. G.

    1996-08-01

    Steady-state finite-element models have been formulated to investigate the coupled fluid flow and thermal behavior of the top-surface flux layers in continuous casting of steel slabs. The three-dimensional (3-D) FIDAP model includes the shear stresses imposed on the flux/steel interface by flow velocities calculated in the molten steel pool. It also includes different temperature-dependent powder properties for solidification and melting. Good agreement between the 3-D model and experimental measurements was obtained. The shear forces, imposed by the steel surface motion toward the submerged entry nozzle (SEN), create a large recirculation zone in the liquid flux pool. Its depth increases with increasing casting speed, increasing liquid flux conductivity, and decreasing flux viscosity. For typical conditions, this zone contains almost 4 kg of flux, which contributes to an average residence time of about 2 minutes. Additionally, because the shear forces produced by the narrowface consumption and the steel flow oppose each other, the flow in the liquid flux layer separates at a location centered 200 mm from the narrowface wall. This flow separation depletes the liquid flux pool at this location and may contribute to generically poor feeding of the mold-strand gap there. As a further consequence, a relatively cold spot develops at the wideface mold wall near the separation point. This nonuniformity in the temperature distribution may result in nonuniform heat removal, and possibly nonuniform initial shell growth in the meniscus region along the wideface off-corner region. In this way, potential steel quality problems may be linked to flow in the liquid flux pool.

  6. Study on Control Algorithm for Continuous Segments Trajectory Interpolation

    Institute of Scientific and Technical Information of China (English)

    SHI Chuan; YE Peiqing; LV Qiang

    2006-01-01

    In CNC machining, the complexity of the part contour causes a series of problems including the repeated start-stop of the motor, low machining efficiency, and poor machining quality. To relieve those problems, a new interpolation algorithm was put forward to realize the interpolation control of continuous sections trajectory. The relevant error analysis of the algorithm was also studied. The feasibility of the algorithm was proved by machining experiment using a laser machine to carve the interpolation trajectory in the CNC system GT100. This algorithm effectively improved the machining efficiency and the contour quality.

  7. MODIS Surface Temperatures for Cryosphere Studies (Invited)

    Science.gov (United States)

    Hall, D. K.; Comiso, J. C.; DiGirolamo, N. E.; Shuman, C. A.; Riggs, G. A.

    2013-12-01

    We have used Moderate-resolution Imaging Spectroradiometer (MODIS) land-surface temperature (LST) and ice-surface temperature (IST) products for several applications in studies of the cryosphere. A climate-quality climate data record (CDR) of the IST of the Greenland ice sheet has been developed and was one of the data sources used to monitor the extreme melt event covering nearly the entire Greenland ice sheet on 11 - 12 July 2012. The IST CDR is available online for users to employ in models, and to study temperature distributions and melt trends on the ice sheet. We continue to assess accuracy of the IST product through comparative analysis with air temperature data from the NOAA Logan temperature sensor at Summit Station, Greenland. We find a small offset between the air temperature and the IST with the IST being slightly lower which is consistent with findings of other studies. The LST data product has been applied in studies of snow melt in regions where snow is a significant water resource. We have used LST data in seasonally snow-covered areas such as the Wind River Range, Wyoming, to monitor the relationship between LST and seasonal streamflow. A close association between a sudden and sustained increase in LST and complete snowmelt, and between melt-season maximum LST and maximum daily streamflow has been documented. Use of LST and MODIS snow-cover and products in hydrological models increases the accuracy of the modeled prediction of runoff. The IST and LST products have also been applied to study of sea ice, e.g. extent and concentration, and lake ice, such as determining ice-out dates, and these efforts will also be described.

  8. Laboratory Studies of Cometary Materials - Continuity Between Asteroid and Comet

    Science.gov (United States)

    Messenger, Scott; Walker, Robert M.

    2015-01-01

    Laboratory analysis of cometary samples have been enabled by collection of cometary dust in the stratosphere by high altitude aircraft and by the direct sampling of the comet Wild-2 coma by the NASA Stardust spacecraft. Cometary materials are composed of a complex assemblage of highly primitive, unprocessed interstellar and primordial solar system materials as well as a variety of high temperature phases that must have condensed in the inner regions of the protoplanetary disk. These findings support and contradict conclusions of comet properties based solely on astronomical observations. These sample return missions have instead shown that there is a continuity of properties between comets and asteroids, where both types of materials show evidence for primitive and processed materials. Furthermore, these findings underscore the importance and value of direct sample return. There will be great value in comparing the findings of the Stardust cometary coma sample return mission with those of future asteroid surface sample returns OSIRIS-REx and Hayabusa II as well as future comet nucleus sample returns.

  9. High-performance wearable supercapacitors fabricated with surface activated continuous filament graphite fibers

    Science.gov (United States)

    Jia, Dedong; Yu, Xin; Chen, Tinghan; Wang, Shu; Tan, Hua; Liu, Hong; Wang, Zhong Lin; Li, Linlin

    2017-08-01

    Generally, carbon or graphite fibers (GFs) are used as the supporting materials for the preparation of flexible supercapacitors (SCs) by assembling various electrochemically active nanomaterials on them. A facile and rapid electrochemical oxidation method with a voltage of 3 V in a mixed H2SO4-HNO3 solution for 2-15 min is proposed to active continuous filament GFs. Detailed structural characterization, SEM, TEM, XRD, Raman and XPS demonstrate that the GFs-8 (oxidized for 8 min) possessing high specific surface area which provided numerous electrochemical sites and a large number of oxygen-containing functional groups producing pseudocapacitance. Cyclic voltammetric (CV), galvanostatic charge-discharge measurements and electrochemical impedance spectroscopy (EIS) are conducted to test the capacitive of GFs and activated GFs. The capacitance of GFs-8 reaches as high as 570 mF cm-1 at the current density of 1 mA cm-1 in LiCl electrolyte, a 1965-fold enhancement with respect to the pristine GFs (0.29 mF cm-1). The fabricated fiber solid-state supercapacitors (SSCs) provide high energy density of 0.68 mWh cm-3 at the power density 3.3 W cm-3 and have excellent durability with 90% capacitance retention after 10000 cycles. In addition, such fiber SSCs features flexibility and mechanical stability, which may have wide applications in wearable electronic devices.

  10. Continuous surface force based lattice Boltzmann equation method for simulating thermocapillary flow

    Science.gov (United States)

    Zheng, Lin; Zheng, Song; Zhai, Qinglan

    2016-02-01

    In this paper, we extend a lattice Boltzmann equation (LBE) with continuous surface force (CSF) to simulate thermocapillary flows. The model is designed on our previous CSF LBE for athermal two phase flow, in which the interfacial tension forces and the Marangoni stresses as the results of the interface interactions between different phases are described by a conception of CSF. In this model, the sharp interfaces between different phases are separated by a narrow transition layers, and the kinetics and morphology evolution of phase separation would be characterized by an order parameter via Cahn-Hilliard equation which is solved in the frame work of LBE. The scalar convection-diffusion equation for temperature field is resolved by thermal LBE. The models are validated by thermal two layered Poiseuille flow, and two superimposed planar fluids at negligibly small Reynolds and Marangoni numbers for the thermocapillary driven convection, which have analytical solutions for the velocity and temperature. Then thermocapillary migration of two/three dimensional deformable droplet are simulated. Numerical results show that the predictions of present LBE agreed with the analytical solution/other numerical results.

  11. Continuous surface force based lattice Boltzmann equation method for simulating thermocapillary flow

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Lin, E-mail: lz@njust.edu.cn [School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Zheng, Song [School of Mathematics and Statistics, Zhejiang University of Finance and Economics, Hangzhou 310018 (China); Zhai, Qinglan [School of Economics Management and Law, Chaohu University, Chaohu 238000 (China)

    2016-02-05

    In this paper, we extend a lattice Boltzmann equation (LBE) with continuous surface force (CSF) to simulate thermocapillary flows. The model is designed on our previous CSF LBE for athermal two phase flow, in which the interfacial tension forces and the Marangoni stresses as the results of the interface interactions between different phases are described by a conception of CSF. In this model, the sharp interfaces between different phases are separated by a narrow transition layers, and the kinetics and morphology evolution of phase separation would be characterized by an order parameter via Cahn–Hilliard equation which is solved in the frame work of LBE. The scalar convection–diffusion equation for temperature field is resolved by thermal LBE. The models are validated by thermal two layered Poiseuille flow, and two superimposed planar fluids at negligibly small Reynolds and Marangoni numbers for the thermocapillary driven convection, which have analytical solutions for the velocity and temperature. Then thermocapillary migration of two/three dimensional deformable droplet are simulated. Numerical results show that the predictions of present LBE agreed with the analytical solution/other numerical results. - Highlights: • A CSF LBE to thermocapillary flows. • Thermal layered Poiseuille flows. • Thermocapillary migration.

  12. Reinitialised versus continuous regional climate simulations using ALARO-0 coupled to the land surface model SURFEXv5

    Science.gov (United States)

    Berckmans, Julie; Giot, Olivier; De Troch, Rozemien; Hamdi, Rafiq; Ceulemans, Reinhart; Termonia, Piet

    2017-01-01

    Dynamical downscaling in a continuous approach using initial and boundary conditions from a reanalysis or a global climate model is a common method for simulating the regional climate. The simulation potential can be improved by applying an alternative approach of reinitialising the atmosphere, combined with either a daily reinitialised or a continuous land surface. We evaluated the dependence of the simulation potential on the running mode of the regional climate model ALARO coupled to the land surface model Météo-France SURFace EXternalisée (SURFEX), and driven by the ERA-Interim reanalysis. Three types of downscaling simulations were carried out for a 10-year period from 1991 to 2000, over a western European domain at 20 km horizontal resolution: (1) a continuous simulation of both the atmosphere and the land surface, (2) a simulation with daily reinitialisations for both the atmosphere and the land surface and (3) a simulation with daily reinitialisations of the atmosphere while the land surface is kept continuous. The results showed that the daily reinitialisation of the atmosphere improved the simulation of the 2 m temperature for all seasons. It revealed a neutral impact on the daily precipitation totals during winter, but the results were improved for the summer when the land surface was kept continuous. The behaviour of the three model configurations varied among different climatic regimes. Their seasonal cycle for the 2 m temperature and daily precipitation totals was very similar for a Mediterranean climate, but more variable for temperate and continental climate regimes. Commonly, the summer climate is characterised by strong interactions between the atmosphere and the land surface. The results for summer demonstrated that the use of a daily reinitialised atmosphere improved the representation of the partitioning of the surface energy fluxes. Therefore, we recommend using the alternative approach of the daily reinitialisation of the atmosphere for

  13. Wrist Hypothermia Related to Continuous Work with a Computer Mouse: A Digital Infrared Imaging Pilot Study

    OpenAIRE

    Jelena Reste; Tija Zvagule; Natalja Kurjane; Zanna Martinsone; Inese Martinsone; Anita Seile; Ivars Vanadzins

    2015-01-01

    Computer work is characterized by sedentary static workload with low-intensity energy metabolism. The aim of our study was to evaluate the dynamics of skin surface temperature in the hand during prolonged computer mouse work under different ergonomic setups. Digital infrared imaging of the right forearm and wrist was performed during three hours of continuous computer work (measured at the start and every 15 minutes thereafter) in a laboratory with controlled ambient conditions. Four people p...

  14. Comparative study of homotopy continuation methods for nonlinear algebraic equations

    Science.gov (United States)

    Nor, Hafizudin Mohamad; Ismail, Ahmad Izani Md.; Majid, Ahmad Abd.

    2014-07-01

    We compare some recent homotopy continuation methods to see which method has greater applicability and greater accuracy. We test the methods on systems of nonlinear algebraic equations. The results obtained indicate the superior accuracy of Newton Homotopy Continuation Method (NHCM).

  15. THE METHOD OF ROLL SURFACE QUALITY MEASUREMENT FOR CONTINUOUS HOT DIP ZINC COATED STEEL SHEET PRODUCTION LINE

    Directory of Open Access Journals (Sweden)

    Ki Yong Choi

    2015-01-01

    Full Text Available The present paper describes a developed analyzing system of roll surface during the process of continuous hot dip zinc coated steel sheet production line, in particular, adhering problem by transferred inclusions from roll to steel sheet surface during annealing process so called the pickup. The simulated test machine for coated roll surface in processing line has been designed and performed. The system makes it possible to analyze roll surface condition according to pickup phenomena from various roll coatings concerning operating conditions of hearth rolls in annealing furnace. The algorithm of fast pickup detection on surface is developed on the base of processing of several optical images of surface. The parameters for quality estimation of surface with pickups were developed. The optical system for images registration and image processing electronics may be used in real time and embed in processing line.

  16. Using Selective Drainage Methods to Extract Continuous Surface Flow from 1-Meter Lidar-Derived Digital Elevation Data

    Science.gov (United States)

    Poppenga, Sandra K.; Worstell, Bruce B.; Stoker, Jason M.; Greenlee, Susan K.

    2010-01-01

    Digital elevation data commonly are used to extract surface flow features. One source for high-resolution elevation data is light detection and ranging (lidar). Lidar can capture a vast amount of topographic detail because of its fine-scale ability to digitally capture the surface of the earth. Because elevation is a key factor in extracting surface flow features, high-resolution lidar-derived digital elevation models (DEMs) provide the detail needed to consistently integrate hydrography with elevation, land cover, structures, and other geospatial features. The U.S. Geological Survey has developed selective drainage methods to extract continuous surface flow from high-resolution lidar-derived digital elevation data. The lidar-derived continuous surface flow network contains valuable information for water resource management involving flood hazard mapping, flood inundation, and coastal erosion. DEMs used in hydrologic applications typically are processed to remove depressions by filling them. High-resolution DEMs derived from lidar can capture much more detail of the land surface than courser elevation data. Therefore, high-resolution DEMs contain more depressions because of obstructions such as roads, railroads, and other elevated structures. The filling of these depressions can significantly affect the DEM-derived surface flow routing and terrain characteristics in an adverse way. In this report, selective draining methods that modify the elevation surface to drain a depression through an obstruction are presented. If such obstructions are not removed from the elevation data, the filling of depressions to create continuous surface flow can cause the flow to spill over an obstruction in the wrong location. Using this modified elevation surface improves the quality of derived surface flow and retains more of the true surface characteristics by correcting large filled depressions. A reliable flow surface is necessary for deriving a consistently connected drainage

  17. STUDIES ON CONTINUOUS GRINDING PROCESS FOR DRIED WATER CHESTNUT KERNEL

    Directory of Open Access Journals (Sweden)

    S.K. GARG

    2010-06-01

    Full Text Available Grinding is a unit operation to break big solid material into smaller pieces. As far as process of grinding is concerned, power consumption, specific energy consumption and particle size distribution and mill capacity are main considerations from engineering point of view. The experiments were conducted to study the effect of speed of mill, sieve size, feed rate and time of grinding on power consumption and average particle diameter of water chestnut in continuous grinding process. Power consumption was measured for a constant feed rate of 1 and 2 kg/h at different speed of the mill varied from 800 to 1200 rpm for the sieve openings of 0.5 mm, 1.0 mm and 2.0 mm. For all the sieve sizes and feed rates, it was observed that as the speed of the mill increases, there is an increase in power consumption and found significantly low for higher sieve size and lower feed rate. The size distribution of the water chestnut kernel for different speeds and sieve sizes at constant feed rate were obtained by sieve analysis. The milling speed has no significant effect on particle size distribution of ground product and mass fraction was minimum at lower feed rate and higher sieve size. Harris model was found best suitable to describe the size distribution in continuous grinding process. Fineness modulus decreases with increase of milling speed for experimental sieve size and feed rate.

  18. A simple technique for continuous measurement of time-variable gas transfer in surface waters

    Science.gov (United States)

    Bohlke, Johnkarl F.; Harvey, Judson W.; Busenberg, Eurybiades; Tobias, Craig R.

    2009-01-01

    Mass balance models of dissolved gases in streams, lakes, and rivers serve as the basis for estimating wholeecosystem rates for various biogeochemical processes. Rates of gas exchange between water and the atmosphere are important and error-prone components of these models. Here we present a simple and efficient modification of the SF6 gas tracer approach that can be used concurrently while collecting other dissolved gas samples for dissolved gas mass balance studies in streams. It consists of continuously metering SF6-saturated water directly into the stream at a low rate of flow. This approach has advantages over pulse injection of aqueous solutions or bubbling large amounts of SF6 into the stream. By adding the SF6 as a saturated solution, we minimize the possibility that other dissolved gas measurements are affected by sparging and/or bubble injecta. Because the SF6 is added continuously we have a record of changing gas transfer velocity (GTV) that is contemporaneous with the sampling of other nonconservative ambient dissolved gases. Over a single diel period, a 30% variation in GTV was observed in a second-order stream (Sugar Creek, Indiana, USA). The changing GTV could be attributed in part to changes in temperature and windspeed that occurred on hourly to diel timescales.

  19. Relationships between the surface quality of a single crystal copper ingot and the process parameters of a heated mould continuous casting method

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The relationships between the surface quality of a single crystal copper ingot and the process parameters of heated mould continuous casting method were studied experimentally using our own design of horizontal heated mould continuous casting apparatus, and the mechanism by which process parameters affect the surface quality of a single crystal copper ingot is analyzed in the present paper. The results show that the process parameters affect the surface quality of a pure copper ingot by affecting the position of the liquid-solid interface in the mould. The position of the liquid-solid interface in the mould must be controlled carefully within an appropriate range, which is determined through a series of experiments,in order to gain a single crystal copper ingot with good surface quality.

  20. Continuous sheathless microparticle and cell patterning using CL-SSAWs (conductive liquid-based standing surface acoustic waves)

    Science.gov (United States)

    Nam, Jeonghun; Kim, Jae Young; Lim, Chae Seung

    2017-01-01

    We present continuous, sheathless microparticle patterning using conductive liquid (CL)-based standing surface acoustic waves (SSAWs). Conventional metal electrodes patterned on a piezoelectric substrate were replaced with electrode channels filled with a CL. The device performance was evaluated with 5-μm fluorescent polystyrene particles at different flow rate and via phase shifting. In addition, our device was further applied to continuous concentration of malaria parasites at the sidewalls of the fluidic channel.

  1. Continuous sheathless microparticle and cell patterning using CL-SSAWs (conductive liquid-based standing surface acoustic waves

    Directory of Open Access Journals (Sweden)

    Jeonghun Nam

    2017-01-01

    Full Text Available We present continuous, sheathless microparticle patterning using conductive liquid (CL-based standing surface acoustic waves (SSAWs. Conventional metal electrodes patterned on a piezoelectric substrate were replaced with electrode channels filled with a CL. The device performance was evaluated with 5-μm fluorescent polystyrene particles at different flow rate and via phase shifting. In addition, our device was further applied to continuous concentration of malaria parasites at the sidewalls of the fluidic channel.

  2. Design studies of continuously variable transmissions for electric vehicles

    Science.gov (United States)

    Parker, R. J.; Loewenthal, S. H.; Fischer, G. K.

    1981-01-01

    Preliminary design studies were performed on four continuously variable transmission (CVT) concepts for use with a flywheel equipped electric vehicle of 1700 kg gross weight. Requirements of the CVT's were a maximum torque of 450 N-m (330 lb-ft), a maximum output power of 75 kW (100 hp), and a flywheel speed range of 28,000 to 14,000 rpm. Efficiency, size, weight, cost, reliability, maintainability, and controls were evaluated for each of the four concepts which included a steel V-belt type, a flat rubber belt type, a toroidal traction type, and a cone roller traction type. All CVT's exhibited relatively high calculated efficiencies (68 percent to 97 percent) over a broad range of vehicle operating conditions. Estimated weight and size of these transmissions were comparable to or less than equivalent automatic transmission. The design of each concept was carried through the design layout stage.

  3. Colonic epithelial cell expression of ICAM-1 relates to loss of surface continuity

    DEFF Research Database (Denmark)

    Vainer, Ben; Horn, Thomas; Nielsen, Ole Haagen

    2006-01-01

    . The aim of this study was to assess the ICAM-1 expression in human colonic tissue representing UC, Crohn's disease (CD), adenomas, and adenocarcinomas, with special attention to the epithelium. MATERIAL AND METHODS: Formalin-fixed and paraffin-embedded tissue from the archives of the Department...... of Pathology of Rigshospitalet University of Copenhagen was examined. Colonic tissue from 10 patients with UC, 10 with CD, 32 adenomas, 27 adenocarcinomas, and 10 lymph node metastases were included. The expression of ICAM-1 was assessed by using the EnVision(+)technique (DakoCytomation). RESULTS: Endothelial...... ICAM-1 was up-regulated in areas with dense lymphocyte infiltration and near crypt abscesses and ulcerations. Ulcerations were covered by a continuous layer of macrophages and epithelial cells expressing ICAM-1. Similar observations were made in the case of adenomas and adenocarcinomas...

  4. Multiple Continuous Differential GPS Records of Surface Speed on the Bench Glacier, Alaska

    Science.gov (United States)

    Anderson, R. S.; O'Neel, S.; Anderson, S. P.; Loso, M. G.

    2002-12-01

    Traditional measurement of glacier surface speed is labor intensive and weather-dependent. While it is thought that sliding speeds are tightly coupled to the subglacial hydrologic system, the nature of the connections requires further elucidation. We deployed 5 GPS receivers at ~ 1 km intervals from the terminus into the accumulation area on the Bench Glacier, Chugach Range, Alaska, and a base station on a nearby bedrock ridge from mid-May through mid-July, 2002. Simultaneous measurement of the terminal stream discharge and air temperature allowed us to constrain meteorological forcing and to calculate the evolution of subglacial water storage. The 4-hour resolution ice surface velocity record reveals that departure from the low early season speeds of roughly 3-5 cm/d occurs progressively upglacier from JD 145 to JD 149; peak speeds were attained within about a week, and were 2-3-fold above background. This is in accord with optical surveying records from 1999 and 2000, although in 2002 the onset of anomalous motion is more subtle, progresses more rapidly upglacier (500-700 m/d) and is of longer duration. However, the stream responded very little to this sliding event; discharge remained at 1-2 m3/s over this interval. In contrast, a high air temperature/melt event (JD 166-168) triggered simultaneous rapid motion (up to 30 cm/d) at all stakes except the highest. Stream discharge rose to 7 m3/s within hours, and remained high, even after the termination of rapid sliding 3 days later. Total sliding during this event varied from 0.2 m at the terminus to 0.7 m at the ELA, while bed separation deduced from the vertical component is roughly one quarter of this. Motion becomes glacier surface-parallel within a week after the termination of sliding. Post-event speeds were consistently below the speeds of the more subtle early event. We interpret this data as follows. In early season, poorly connected cavities prevent efficient subglacial drainage of the snowmelt inputs

  5. Case studies continue to illuminate the cognitive neuroscience of memory.

    Science.gov (United States)

    Rosenbaum, R Shayna; Gilboa, Asaf; Moscovitch, Morris

    2014-05-01

    The current ubiquity of functional neuroimaging studies, and the importance they have had in elucidating brain function, obscures the fact that much of what we know about brain-behavior relationships derives largely from the study of single- and multiple-patient cases. A major goal of the present review is to describe how single cases continue to uniquely and critically contribute to cognitive neuroscience theory. With several recent examples from the literature, we demonstrate that single cases can both challenge accepted dogma and generate hypotheses and theories that steer the field in new directions. We discuss recent findings from case studies that specify critical functions of the hippocampus in episodic memory and recollection, and clarify its role in nonmnemonic abilities. Although we focus on the hippocampus, we discuss other regions and the occurrence of new associative learning, as well as the involvement of the ventromedial prefrontal and parietal cortices in memory encoding and retrieval. We also describe ways of dealing with the shortcomings of case studies, and emphasize the partnership of patient and neuroimaging methods in constraining neurocognitive models of memory.

  6. Continuous manufacturing of tablets with PROMIS-line - Introduction and case studies from continuous feeding, blending and tableting.

    Science.gov (United States)

    Simonaho, Simo-Pekka; Ketolainen, Jarkko; Ervasti, Tuomas; Toiviainen, Maunu; Korhonen, Ossi

    2016-07-30

    Drug manufacturing technology is in the midst of modernization and continuous manufacturing of drug products is especially the focus of great interest. The adoption of new manufacturing approaches requires extensive cooperation between industry, regulatory bodies, academics and equipment manufacturers. In this paper we introduce PROMIS-line which is a continuous tableting line built at the University of Eastern Finland, School of Pharmacy, PROMIS-centre. PROMIS-line is modular and tablets can be produced via dry granulation or direct compression. In three case studies, continuous feeding, blending and tablet performance is studied to illustrate some basic features of PROMIS-line. In conclusion, the PROMIS-line is an excellent tool for studying the fundamentals of continuous manufacturing of tablets.

  7. Surface studies of plasma processed Nb samples

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Puneet V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Doleans, Marc [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Hannah, Brian S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Afanador, Ralph [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Stewart, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Mammosser, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Howell, Matthew P [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Saunders, Jeffrey W [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Degraff, Brian D [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Kim, Sang-Ho [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)

    2015-01-01

    Contaminants present at top surface of superconducting radio frequency (SRF) cavities can act as field emitters and restrict the cavity accelerating gradient. A room temperature in-situ plasma processing technology for SRF cavities aiming to clean hydrocarbons from inner surface of cavities has been recently developed at the Spallation Neutron Source (SNS). Surface studies of the plasma-processed Nb samples by Secondary ion mass spectrometry (SIMS) and Scanning Kelvin Probe (SKP) showed that the NeO2 plasma processing is very effective to remove carbonaceous contaminants from top surface and improves the surface work function by 0.5 to 1.0 eV.

  8. CONSTRUCTION OF G2 CONTINUOUS CURVES ON SURFACE WITH PLANAR CUBIC B(E)ZIER CURVES

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaoping; Zhang Weizhong; Zhang Liyan; Zhou Rurong

    2005-01-01

    The problem of constructing curve on parametric surface (or surface that can be parameterized) such that it interpolates a sequence of points with prescribed tangent direction and curvature vector (or geodesic curvature) at every point and the issue of curve blending on this kind of surface are researched. The mapping and tangent mapping from the surface to its parametric plane are introduced and thus several conclusions with differential geometry are deduced. Based on those conclusions, the problem of interpolating (or blending) curve on a parametric surface is converted to a similar one on its parametric plane. The final solution curve of either interpolation or blending issue is explicit and can still be expressed by parametric form. And so, unlike existing methods, the presented method needs not to use any surface/surface intersection algorithms, usually a troublesome process, for displaying such interpolation curve. Experiment results show the presented methods are feasible and applicable to CAD/CAM and computer graphics.

  9. Correlation studies on surface particle detection methods

    Science.gov (United States)

    Peterson, Ronald V.; White, James C.

    1988-01-01

    The accurate determination of dust levels on optical surfaces is necessary to assess sensor system performance. A comparison study was made on several particle measurement methods including those based on direct imaging and light scattering. The effectiveness of removing the particles from the surface prior to determining particle size distributions was also assessed. These studies revealed that some methods, especially those requiring particle removal before analysis, are subject to large systematic errors affecting particle size distributions. Thus, an understanding of the particle measurement methods employed is necessary before any surface cleanliness or obstruction value assignments are accepted as true representations of an optical surface contamination condition.

  10. Results from one-year continuous operation of a large aperture scintillometer over a heterogeneous land surface

    NARCIS (Netherlands)

    Beyrich, F.; DeBruin, H.A.R.; Meijninger, W.M.L.; Schipper, J.W.; Lohse, H.

    2002-01-01

    A large-aperture scintillometer (LAS) was operated continuously during a period of more than one year over a heterogeneous land surface in Central Europe at the transition between marine and continental climates. The LAS measurements of the refractive index structure parameter, C N2, were used to es

  11. On the Heat Transfer through a Solid Slab Heated Uniformly and Continuously on One of Its Surfaces

    Science.gov (United States)

    Marin, E.; Lara-Bernal, A.; Calderon, A.; Delgado-Vasallo, O.

    2011-01-01

    Some peculiarities of the heat transfer through a sample that is heated by the superficial absorption of light energy under continuous uniform illumination are discussed. We explain, using a different approach to that presented in a recent article published in this journal (Salazar "et al" 2010 "Eur. J. Phys." 31 1053-9), that the front surface of…

  12. Continuity, but at what cost? The impact of telemonitoring COPD on continuities of care: a qualitative study.

    Science.gov (United States)

    Fairbrother, Peter; Pinnock, Hilary; Hanley, Janet; McCloughan, Lucy; Sheikh, Aziz; Pagliari, Claudia; McKinstry, Brian

    2012-09-01

    Continuity of care is widely regarded as an important marker of quality in the management of patients with long-term conditions. New services that integrate telemonitoring into care pathways have potential to change aspects of continuity in both positive and negative ways. A telemonitoring service for patients with chronic obstructive pulmonary disease (COPD) was introduced in Lothian, Scotland, in 2009. A qualitative study, nested within the TELESCOT COPD randomised control trial, was undertaken to explore the views of patients and professionals on telemonitoring. The perceived impact of telemonitoring on continuity of care was investigated as part of the research. Semi-structured interviews were undertaken with 38 patients (47% male, mean age 67.5 years). A maximum variation sample in relation to age, sex, socio-economic background, disease severity, and compliance with telemonitoring was recruited. Thirty-two stakeholders (healthcare professionals and managers) were interviewed. Transcribed coded data were analysed thematically using the framework approach. Interpretation was supported by multidisciplinary discussion. Patients and healthcare professionals considered that relationship-based continuity of care was important in the delivery of telemonitoring services. Managers placed emphasis on improved continuity of clinical management as a means of reducing healthcare costs. However, professionals described many operational challenges arising from the 'bolting-on' of telemonitoring provision to existing usual care provision which, they considered, resulted in the proliferation of additional managerial discontinuities. Managers and healthcare professionals face major challenges in meeting demands for both relationship continuity and continuity of clinical management in the development of telemonitoring services.

  13. A study on the continuing education of radiologic technologists: Focused on current status and satisfaction of continuing education

    Energy Technology Data Exchange (ETDEWEB)

    Min, Hye Lim; Choi, In Seok; Nam, So Ra; Kim, Hyun Ji; Yoon, Yong Su; Her, Jae; Han, Seong Gyu; Kim, Jung Min [Dept. of bio-convergence engineering, graduate school, Korea university, Seoul (Korea, Republic of); Ahn, Duck Sun [Korea university college of medicine, Seoul (Korea, Republic of)

    2014-06-15

    In this study, we surveyed the current status, satisfaction and demand of radiologic technologist continuing education for 93 radiologic technologists who participated in the continuing education. To understand the current status and general evaluation and to find out the improvement direction, survey was conducted on 3 categories: participation, satisfaction and demand of continuing education. In addition, we analyzed the continuing education implementation status and the management system by collecting related regulations. As a result, the education completion rates of radiologic technologists from 2010 to 2012 were respectively 42.6%, 43.4% and 34.2%; the rates were similar to other medical technician’s average education completion rates. According to the survey, in case of participation, the most frequent answer was ‘more than five times less than 10 times per year’ with 48.4% and in satisfaction section, the most common answer was ‘Average(3)’ with 34.4%. In demand of continuing education section, 32.8% of the respondents chose ‘Clinical skill training in major field’. In the results of this research, continuing education needs to be managed in the direction of helping radiologists improve their personal ability and self development. Furthermore, to meet the demand of radiologists, the quality of continuing education should be improved to satisfy the educatee.

  14. Continuous Wavelet Transform Analysis of Surface Electromyography for Muscle Fatigue Assessment on the Elbow Joint Motion

    Directory of Open Access Journals (Sweden)

    Triwiyanto Triwiyanto

    2017-01-01

    Full Text Available Studying muscle fatigue plays an important role in preventing the risks associated with musculoskeletal disorders. The effect of elbow-joint angle on time-frequency parameters during a repetitive motion provides valuable information in finding the most accurate position of the angle causing muscle fatigue. Therefore, the purpose of this study is to analyze the effect of muscle fatigue on the spectral and time-frequency domain parameters derived from electromyography (EMG signals using the Continuous Wavelet Transform (CWT. Four male participants were recruited to perform a repetitive motion (flexion and extension movements from a non-fatigue to fatigue condition. EMG signals were recorded from the biceps muscle. The recorded EMG signals were then analyzed offline using the complex Morlet wavelet. The time-frequency domain data were analyzed using the time-averaged wavelet spectrum (TAWS and the Scale-Average Wavelet Power (SAWP parameters. The spectral domain data were analyzed using the Instantaneous Mean Frequency (IMNF and the Instantaneous Mean Power Spectrum (IMNP parameters. The index of muscle fatigue was observed by calculating the increase of the IMNP and the decrease of the IMNF parameters. After performing a repetitive motion from non-fatigue to fatigue condition, the average of the IMNF value decreased by 15.69% and the average of the IMNP values increased by 84%, respectively. This study suggests that the reliable frequency band to detect muscle fatigue is 31.10-36.19Hz with linear regression parameters of 0.979mV^2Hz^(-1 and 0.0095mV^2Hz^(-1 for R^2 and slope, respectively.

  15. Numerical Continuation Methods for Intrusive Uncertainty Quantification Studies

    Energy Technology Data Exchange (ETDEWEB)

    Safta, Cosmin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Najm, Habib N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Phipps, Eric Todd [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    Rigorous modeling of engineering systems relies on efficient propagation of uncertainty from input parameters to model outputs. In recent years, there has been substantial development of probabilistic polynomial chaos (PC) Uncertainty Quantification (UQ) methods, enabling studies in expensive computational models. One approach, termed ”intrusive”, involving reformulation of the governing equations, has been found to have superior computational performance compared to non-intrusive sampling-based methods in relevant large-scale problems, particularly in the context of emerging architectures. However, the utility of intrusive methods has been severely limited due to detrimental numerical instabilities associated with strong nonlinear physics. Previous methods for stabilizing these constructions tend to add unacceptably high computational costs, particularly in problems with many uncertain parameters. In order to address these challenges, we propose to adapt and improve numerical continuation methods for the robust time integration of intrusive PC system dynamics. We propose adaptive methods, starting with a small uncertainty for which the model has stable behavior and gradually moving to larger uncertainty where the instabilities are rampant, in a manner that provides a suitable solution.

  16. LBM-LES Simulation of the Transient Asymmetric Flow and Free Surface Fluctuations under Steady Operating Conditions of Slab Continuous Casting Process

    Science.gov (United States)

    Zhao, Peng; Li, Qiang; Kuang, S. B.; Zou, Zongshu

    2017-02-01

    Transient flow structures in a continuous casting mold can strongly influence the slag entrainment in liquid steel and the bubbles capture in the initial solidified shell, both of which are associated with the quality of the final product. This paper presents a numerical study of the turbulent flow with a top free surface in the continuous casting mold at a meso-scale level by a three-dimensional combined approach of Free Surface Lattice Boltzmann Method and Large Eddy Simulation (FSLBM-LES). The validity of the model is verified by the good agreement between the calculated results and the measurements from various water experiments in terms of the flow velocity and free surface profile. The mathematical model is then used to reveal the transient and spatiotemporal asymmetric characteristics associated with the transient flow field and the free surface fluctuation, although the steady state operation is considered during the continuous casting process. The results show that the locations of the jets of liquid steel from the two out ports of the Submerged Entry Nozzle (SEN) always fluctuate alternatively within a certain range, and periodically deviate from the design angle of the SEN within the same time period. The oscillating behavior of the jets promotes the asymmetric flow patterns and multi-scale vortices at both sides of the SEN. By introducing the Q-criterion in the results analysis, the formation, development, and shedding of the coherent structure (CS) of the turbulent flow are quantitatively characterized. The interaction between the transient flow patterns and the fluctuations of the top free surface as well as the evolution of the transient profile and velocities of the free surface are also demonstrated. The results obtained from the current study suggest that the FSLBM-LES model offers a promising way to study the complex flows and related transfer phenomena in the continuous casting process.

  17. Surface studies of gas sensing metal oxides.

    Science.gov (United States)

    Batzill, Matthias; Diebold, Ulrike

    2007-05-21

    The relation of surface science studies of single crystal metal oxides to gas sensing applications is reviewed. Most metal oxide gas sensors are used to detect oxidizing or reducing gases and therefore this article focuses on surface reduction processes and the interaction of oxygen with these surfaces. The systems that are discussed are: (i) the oxygen vacancy formation on the surface of the ion conductor CeO(2)(111); (ii) interaction of oxygen with TiO(2) (both adsorption processes and the incorporation of oxygen into the TiO(2)(110) lattice are discussed); (iii) the varying surface composition of SnO(2)(101) and its consequence for the adsorption of water; and (iv) Cu modified ZnO(0001)-Zn surfaces and its interaction with oxygen. These examples are chosen to give a comprehensive overview of surface science studies of different kinds of gas sensing materials and to illustrate the potential that surface science studies have to give fundamental insight into gas sensing phenomena.

  18. Variable Camber Continuous Aerodynamic Control Surfaces and Methods for Active Wing Shaping Control

    Science.gov (United States)

    Nguyen, Nhan T. (Inventor)

    2016-01-01

    An aerodynamic control apparatus for an air vehicle improves various aerodynamic performance metrics by employing multiple spanwise flap segments that jointly form a continuous or a piecewise continuous trailing edge to minimize drag induced by lift or vortices. At least one of the multiple spanwise flap segments includes a variable camber flap subsystem having multiple chordwise flap segments that may be independently actuated. Some embodiments also employ a continuous leading edge slat system that includes multiple spanwise slat segments, each of which has one or more chordwise slat segment. A method and an apparatus for implementing active control of a wing shape are also described and include the determination of desired lift distribution to determine the improved aerodynamic deflection of the wings. Flap deflections are determined and control signals are generated to actively control the wing shape to approximate the desired deflection.

  19. Surface modification of droplet polymeric microfluidic devices for the stable and continuous generation of aqueous droplets.

    Science.gov (United States)

    Subramanian, Balamurugan; Kim, Namwon; Lee, Wonbae; Spivak, David A; Nikitopoulos, Dimitris E; McCarley, Robin L; Soper, Steven A

    2011-06-21

    Droplet microfluidics performed in poly(methyl methacrylate) (PMMA) microfluidic devices resulted in significant wall wetting by water droplets formed in a liquid-liquid segmented flow when using a hydrophobic carrier fluid such as perfluorotripropylamine (FC-3283). This wall wetting led to water droplets with nonuniform sizes that were often trapped on the wall surfaces, leading to unstable and poorly controlled liquid-liquid segmented flow. To circumvent this problem, we developed a two-step procedure to hydrophobically modify the surfaces of PMMA and other thermoplastic materials commonly used to make microfluidic devices. The surface-modification route involved the introduction of hydroxyl groups by oxygen plasma treatment of the polymer surface followed by a solution-phase reaction with heptadecafluoro-1,1,2,2-tetrahydrodecyl trichlorosilane dissolved in fluorocarbon solvent FC-3283. This procedure was found to be useful for the modification of PMMA and other thermoplastic surfaces, including polycyclic olefin copolymer (COC) and polycarbonate (PC). Angle-resolved X-ray photoelectron spectroscopy indicated that the fluorination of these polymers took place with high surface selectivity. This procedure was used to modify the surface of a PMMA droplet microfluidic device (DMFD) and was shown to be useful in reducing the wetting problem during the generation of aqueous droplets in a perfluorotripropylamine (FC-3283) carrier fluid and could generate stable segmented flows for hours of operation. In the case of PMMA DMFD, oxygen plasma treatment was carried out after the PMMA cover plate was thermally fusion bonded to the PMMA microfluidic chip. Because the appended chemistry to the channel wall created a hydrophobic surface, it will accommodate the use of other carrier fluids that are hydrophobic as well, such as hexadecane or mineral oils.

  20. The Submerged Printing of Cells onto a Modified Surface Using a Continuous Flow Microspotter

    Science.gov (United States)

    Davidoff, Sherry N.; Miles, Adam R.; Romanov, Valentin; Gale, Bruce K.; Eckman, Josh W.; Brooks, Benjamin D.

    2014-01-01

    The printing of cells for microarray applications possesses significant challenges including the problem of maintaining physiologically relevant cell phenotype after printing, poor organization and distribution of desired cells, and the inability to deliver drugs and/or nutrients to targeted areas in the array. Our 3D microfluidic printing technology is uniquely capable of sealing and printing arrays of cells onto submerged surfaces in an automated and multiplexed manner. The design of the microfluidic cell array (MFCA) 3D fluidics enables the printhead tip to be lowered into a liquid-filled well or dish and compressed against a surface to form a seal. The soft silicone tip of the printhead behaves like a gasket and is able to form a reversible seal by applying pressure or backing away. Other cells printing technologies such as pin or ink-jet printers are unable to print in submerged applications. Submerged surface printing is essential to maintain phenotypes of cells and to monitor these cells on a surface without disturbing the material surface characteristics. By printing onto submerged surfaces, cell microarrays are produced that allow for drug screening and cytotoxicity assessment in a multitude of areas including cancer, diabetes, inflammation, infections, and cardiovascular disease. PMID:24796939

  1. Surface study of mercury-cadmium-telluride

    Energy Technology Data Exchange (ETDEWEB)

    Lops, V.C.

    1985-01-01

    Single crystals of Hg/sub 1-x/Cd/sub x/Te were studied to determine how changes in the surface conditions affected electrical properties. Infrared detector grade material from Honeywell Radiation Center (x = 0.2, bandgap near 10 ..mu..m) was used to examine the effects of changes in the surface charge density on electrical I/f noise. The surface charge density, which was controlled by the pH of the aqueous solution was measured in a zeta meter that operated much like a Millikan oil-drop experiment. The electrophoresis zeta potential measurements on (HgCd)Te identified the active surface oxide as TeO/sub 2/ and also revealed information on the surface chemistry. An experimental fit yielded the dissociation constant of tellurous acid, which was the result of TeO/sub 2/ combining with H/sub 2/O. The dissociation of tellurous acid was responsible for the measured surface charge densities and the surface chemistry from pH = 1 to pH = 8. At pH = 1, the surface was H/sub 3/TeO/sub 2//sup +/. At pH = 1.5, the surface was H/sub 2/TeO/sub 3/ which gave the neutral point, PZZP (Point of Zero Zeta Potential). With the pH between 2 and 6, the surface was HTeO/sub 3//sup -/. As the pH was changed to 7 and greater, the surface was TeO/sub 3//sup -/. Electrical I/f noise in (HgCd)Te was found to be dominated by bulk and not surface effects at room temperature.

  2. Simulation study of PET detector limitations using continuous crystals

    Science.gov (United States)

    Cabello, Jorge; Etxebeste, Ane; Llosá, Gabriela; Ziegler, Sibylle I.

    2015-05-01

    Continuous crystals can potentially obtain better intrinsic detector spatial resolution compared to pixelated crystals, additionally providing depth of interaction (DoI) information from the light distribution. To achieve high performance sophisticated interaction position estimation algorithms are required. There are a number of algorithms in the literature applied to different crystal dimensions and different photodetectors. However, the different crystal properties and photodetector array geometries have an impact on the algorithm performance. In this work we analysed, through Monte Carlo simulations, different combinations of realistic crystals and photodetector parameters to better understand their influence on the interaction position estimation accuracy, with special emphasis on the DoI. We used an interaction position estimation based on an analytical model for the present work. Different photodetector granulation schemes were investigated. The impact of the number of crystal faces readout by photodetectors was studied by simulating scenarios with one and two photodetectors. In addition, crystals with different levels of reflection and aspect ratios (AR) were analysed. Results showed that the impact of photodetector granularity is mainly shown near the edges and specially in the corners of the crystal. The resulting intrinsic spatial resolution near the centre with a 12 × 12 × 10 mm3 LYSO crystal was 0.7-0.9 mm, while the average spatial resolution calculated on the entire crystal was 0.77 ± 0.18 mm for all the simulated geometries with one and two photodetectors. Having front and back photodetectors reduced the DoI bias (Euclidean distance between estimated DoI and real DoI) and improved the transversal resolution near the corners. In scenarios with one photodetector, small AR resulted in DoI inaccuracies for absorbed events at the entrance of the crystal. These inaccuracies were slightly reduced either by increasing the AR or reducing the amount of

  3. HEAT TRANSFER IN THREE DIMENSIONAL MHD BOUNDARY LAYER FLOW OVER A CONTINUOUS POROUS SURFACE MOVING IN A PARALLEL FREE STREAM

    Directory of Open Access Journals (Sweden)

    KHEM CHAND

    2011-07-01

    Full Text Available The heat transfer and hydromagnetic boundary layer flow of an electrically conducting viscous ,incompressible fluid over a continuous flat surface moving in a parallel free stream is investigated. The porous infinite surface is subjected to a slightly sinusoidal transverse suction velocity distribution. The flow becomes three dimensional due to this type of suction velocity without taking into account the induced magnetic field; the mathematical analysis is presented for the hydromagnetic laminar boundary layer flow. For the asymptotic flow condition, the components of the surface skin friction and the rate of heat transfer are obtained. During discussion it is found that with the increase of Hartmann number M, the skin friction factor F1 increase sharply for lower values of theReynolds number, but for the large value it increases steadily. But if the surface velocity is more than that of free stream velocity then the reverse trend is observed.

  4. Application of the FlexiForce contact surface force sensor to continuous extraocular compression monitoring during craniotomy for cerebral aneurysms.

    Science.gov (United States)

    Mutoh, Tatsushi; Ishikawa, Tatsuya; Nishimura, Hiromi; Yasui, Nobuyuki

    2010-01-01

    The aims of this study were to introduce our newly developed device equipped with a contact surface force sensor (FlexiForce) for monitoring extraocular compression continuously, and to illustrate its potential clinical application using this device in patients undergoing uncomplicated frontotemporal or bifrontal craniotomy for surgical clipping of unruptured anterior circulation aneurysms. In a pilot study with volunteers, we determined the critical force of 100 gf to cause painful ocular sensation. Then we performed the bilateral extraocular force measurements in 15 patients undergoing uncomplicated frontotemporal or bifrontal craniotomy for surgical clipping of unruptured anterior circulation aneurysms. Extraocular force increased immediately after retraction of the flap, increased to 144+/-26 gf (mean+/-SD) during lower craniotomy close to the orbit, was maintained at 91+/-18 gf during microsurgery, and returned close to baseline at 24+/-14 gf after restoration of skin flap retraction. Such changes were observed only on the surgical side in frontotemporal craniotomy. Abnormal increase in extraocular force was effectively reduced by placing a real-time digital panel meter to warn surgeons to avoid excessive skin flap retraction during the surgical procedure. In conclusion, this new tool may allow us to monitor the external forces that can be applied intraoperatively to the ocular globe in the supine position.

  5. Electrode surface studies by LEED-Auger

    Science.gov (United States)

    Ogrady, W. E.; Woo, M. Y. C.; Hagans, P. L.; Yeager, E.

    1977-01-01

    The role the electronic and geometric structures of the metal surface play in electrochemical surface reactions remains as yet an unknown factor. In order to investigate these surface contributions to electrochemical reactions, a low-energy-electron diffraction (LEED) and an Auger electron spectrometer (AES) have been combined with an electrochemical thin-layer cell. The surface to be studied electrochemically is first characterized by LEED-AES and then transferred into a second chamber where it becomes part of the electrochemical thin-layer cell. Electrochemical reactions are then run on this surface. The sample may then be transferred back to the LEED-AES chamber for further characterization. Data on Pt (111) will be presented.

  6. Measuring floodplain spatial patterns using continuous surface metrics at multiple scales

    Science.gov (United States)

    Murray Scown,; Martin Thoms,; DeJager, Nathan R.

    2015-01-01

    Interactions between fluvial processes and floodplain ecosystems occur upon a floodplain surface that is often physically complex. Spatial patterns in floodplain topography have only recently been quantified over multiple scales, and discrepancies exist in how floodplain surfaces are perceived to be spatially organised. We measured spatial patterns in floodplain topography for pool 9 of the Upper Mississippi River, USA, using moving window analyses of eight surface metrics applied to a 1 × 1 m2 DEM over multiple scales. The metrics used were Range, SD, Skewness, Kurtosis, CV, SDCURV,Rugosity, and Vol:Area, and window sizes ranged from 10 to 1000 m in radius. Surface metric values were highly variable across the floodplain and revealed a high degree of spatial organisation in floodplain topography. Moran's I correlograms fit to the landscape of each metric at each window size revealed that patchiness existed at nearly all window sizes, but the strength and scale of patchiness changed within window size, suggesting that multiple scales of patchiness and patch structure exist in the topography of this floodplain. Scale thresholds in the spatial patterns were observed, particularly between the 50 and 100 m window sizes for all surface metrics and between the 500 and 750 m window sizes for most metrics. These threshold scales are ~ 15–20% and 150% of the main channel width (1–2% and 10–15% of the floodplain width), respectively. These thresholds may be related to structuring processes operating across distinct scale ranges. By coupling surface metrics, multi-scale analyses, and correlograms, quantifying floodplain topographic complexity is possible in ways that should assist in clarifying how floodplain ecosystems are structured.

  7. Continuous monitoring of summer surface water vapor isotopic composition above the Greenland Ice Sheet

    Directory of Open Access Journals (Sweden)

    H. C. Steen-Larsen

    2013-05-01

    Full Text Available We present here surface water vapor isotopic measurements conducted from June to August 2010 at the NEEM (North Greenland Eemian Drilling Project camp, NW Greenland (77.45° N, 51.05° W, 2484 m a.s.l.. Measurements were conducted at 9 different heights from 0.1 m to 13.5 m above the snow surface using two different types of cavity-enhanced near-infrared absorption spectroscopy analyzers. For each instrument specific protocols were developed for calibration and drift corrections. The inter-comparison of corrected results from different instruments reveals excellent reproducibility, stability, and precision with a standard deviations of ~ 0.23‰ for δ18O and ~ 1.4‰ for δD. Diurnal and intraseasonal variations show strong relationships between changes in local surface humidity and water vapor isotopic composition, and with local and synoptic weather conditions. This variability probably results from the interplay between local moisture fluxes, linked with firn–air exchanges, boundary layer dynamics, and large-scale moisture advection. Particularly remarkable are several episodes characterized by high (> 40‰ surface water vapor deuterium excess. Air mass back-trajectory calculations from atmospheric analyses and water tagging in the LMDZiso (Laboratory of Meteorology Dynamics Zoom-isotopic atmospheric model reveal that these events are associated with predominant Arctic air mass origin. The analysis suggests that high deuterium excess levels are a result of strong kinetic fractionation during evaporation at the sea-ice margin.

  8. Variational space–time (dis)continuous Galerkin method for nonlinear free surface water waves

    NARCIS (Netherlands)

    Gagarina, E.; Ambati, V.R.; Vegt, van der J.J.W.; Bokhove, O.

    2014-01-01

    A new variational finite element method is developed for nonlinear free surface gravity water waves using the potential flow approximation. This method also handles waves generated by a wave maker. Its formulation stems from Miles’ variational principle for water waves together with a finite element

  9. Variational space-time (dis)continuous Galerkin method for nonlinear free surface waves

    NARCIS (Netherlands)

    Gagarina, E.; Vegt, van der J.J.W.; Ambati, V.R.; Bokhove, O.

    2013-01-01

    A new variational finite element method is developed for nonlinear free surface gravity water waves. This method also handles waves generated by a wave maker. Its formulation stems from Miles' variational principle for water waves together with a space-time finite element discretization that is cont

  10. A chemical ionization mass spectrometer for continuous underway shipboard analysis of dimethylsulfide in near-surface seawater

    Directory of Open Access Journals (Sweden)

    E. S. Saltzman

    2009-11-01

    Full Text Available A compact, low-cost atmospheric pressure, chemical ionization mass spectrometer ("mini-CIMS" has been developed for continuous underway shipboard measurements of dimethylsulfide (DMS in seawater. The instrument was used to analyze DMS in air equilibrated with flowing seawater across a porous Teflon membrane equilibrator. The equilibrated gas stream was diluted with air containing an isotopically-labeled internal standard. DMS is ionized at atmospheric pressure via proton transfer from water vapor, then declustered, mass filtered via quadrupole mass spectrometry, and detected with an electron multiplier. The instrument described here is based on a low-cost residual gas analyzer (Stanford Research Systems, which has been modified for use as a chemical ionization mass spectrometer. The mini-CIMS has a gas phase detection limit of 220 ppt DMS for a 1 min averaging time, which is roughly equivalent to a seawater DMS concentration of 0.1 nM DMS at 20°C. The mini-CIMS has the sensitivity, selectivity, and time response required for underway measurements of surface ocean DMS over the full range of oceanographic conditions. The simple, robust design and relatively low cost of the instrument are intended to facilitate use in process studies and surveys, with potential for long-term deployment on research vessels, ships of opportunity, and large buoys.

  11. A chemical ionization mass spectrometer for continuous underway shipboard analysis of dimethylsulfide in near-surface seawater

    Directory of Open Access Journals (Sweden)

    E. S. Saltzman

    2009-07-01

    Full Text Available A compact, low-cost atmospheric pressure, chemical ionization mass spectrometer ("mini-CIMS" has been developed for continuous underway shipboard measurements of dimethylsulfide (DMS in seawater. The instrument was used to analyze DMS in air equilibrated with flowing seawater across a porous Teflon membrane equilibrator. The equilibrated gas stream was diluted with air containing an isotopically-labeled internal standard. DMS is ionized at atmospheric pressure via proton transfer from water vapor, then declustered, mass filtered via quadrupole mass spectrometry, and detected with an electron multiplier. The instrument described here is based on a low-cost residual gas analyzer (Stanford Research Systems, which has been modified for use as a chemical ionization mass spectrometer. The mini-CIMS has a gas phase detection limit of 170 ppt DMS for a 1 min averaging time, which is roughly equivalent to a seawater DMS concentration of 0.1 nM DMS at 20°C. The mini-CIMS has the sensitivity, selectivity, and time response required for underway measurements of surface ocean DMS over the full range of oceanographic conditions. The simple, robust design and relatively low cost of the instrument are intended to facilitate use in process studies and surveys, with potential for long-term deployment on research vessels, ships of opportunity, and large buoys.

  12. Comparative study of the surface layer density of liquid surfaces

    Science.gov (United States)

    Chacón, E.; Fernández, E. M.; Duque, D.; Delgado-Buscalioni, R.; Tarazona, P.

    2009-11-01

    Capillary wave fluctuations blur the inherent structure of liquid surfaces in computer simulations. The intrinsic sampling method subtracts capillary wave fluctuations and yields the intrinsic surface structure, leading to a generic picture of the liquid surface. The most relevant magnitude of the method is the surface layer density ns that may be consistently determined from different properties: the layering structure of the intrinsic density profiles, the turnover rate for surface layer particles, and the hydrodynamic damping rate of capillary waves. The good agreement among these procedures provides evidence for the physical consistency of the surface layering hypothesis, as an inherent physical property of the liquid surfaces. The dependence of the surface compactness, roughness, and exchange rate with temperature is analyzed for several molecular interaction models.

  13. Consistent projection methods for variable density incompressible Navier-Stokes equations with continuous surface forces on a rectangular collocated mesh

    Science.gov (United States)

    Ni, Ming-Jiu

    2009-10-01

    Two consistent projection methods of second-order temporal and spatial accuracy have been developed on a rectangular collocated mesh for variable density Navier-Stokes equations with a continuous surface force. Instead of the original projection methods (denoted as algorithms I and II in this paper), in which the updated cell center velocity from the intermediate velocity and the pressure gradient is not guaranteed solenoidal, the consistent projection methods (denoted as algorithms III and IV) obtain the cell center velocity based on an interpolation from a conservative fluxes with velocity unit on surrounding cell faces. Dependent on treatment of the continuous surface force, the pressure gradient in algorithm III or the sum of the pressure gradient and the surface force in algorithm IV at a cell center is then conducted from the difference between the updated velocity and the intermediate velocity in a consistent projection method. A non-viscous 3D static drop with serials of density ratios is numerically simulated. Using the consistent projection methods, the spurious currents can be greatly reduced and the pressure jump across the interface can be accurately captured without oscillations. The developed consistent projection method are also applied for simulation of interface evolution of an initial ellipse driven by the surface tension and of an initial sphere bubble driven by the buoyancy with good accuracy and good resolution.

  14. STUDY ON CONTINUOUS ELECTROREGENERATION OF ION EXCHANEG RESIN

    Institute of Scientific and Technical Information of China (English)

    XuTaishun

    1996-01-01

    In this paper,the continuous electroregeneration of ion exchange resin is investegated.The mixed resin is inserted between a cation exchange membrane and an anion exchange membrane.The effluent water of fresh water room meets the demand for power plant on water treatment.The B2 that is the cumulative formation constant of the metal complexes of resin is very differente with or without electric field.It indicates that the dissociation degree of metal complexes of resin is greater wit electric field than that without electric field.

  15. STUDY ON CONTINUOUS-TIME HEDGING PROBLEM IN INCOMPLETE MARKETS

    Institute of Scientific and Technical Information of China (English)

    刘海龙; 吴冲锋

    2002-01-01

    This paper extended the continuous-time dynamic-hedging theorem for the incomplete markets of Bertsimas, Kogan and Lo's to the case in which riskless interest rate is not zero. The theorem was then proved with the stochastic dynamic programming theory, by constructing a self-financing dynamic strategy that best approximates an arbitrary payoff function in the mean-squared sense. When the riskless interest rate is zero, our optimal hedging strategy coincides with the results of Bertsimas, Kogan and Lo,i.e. their results are special cases of ours.

  16. Entropy Generation Analysis of Open Parallel Microchannels Embedded Within a Permeable Continuous Moving Surface: Application to Magnetohydrodynamics (MHD

    Directory of Open Access Journals (Sweden)

    Mohammad H. Yazdi

    2011-12-01

    Full Text Available This paper presents a new design of open parallel microchannels embedded within a permeable continuous moving surface due to reduction of exergy losses in magnetohydrodynamic (MHD flow at a prescribed surface temperature (PST. The entropy generation number is formulated by an integral of the local rate of entropy generation along the width of the surface based on an equal number of microchannels and no-slip gaps interspersed between those microchannels. The velocity, the temperature, the velocity gradient and the temperature gradient adjacent to the wall are substituted into this equation resulting from the momentum and energy equations obtained numerically by an explicit Runge-Kutta (4, 5 formula, the Dormand-Prince pair and shooting method. The entropy generation number, as well as the Bejan number, for various values of the involved parameters of the problem are also presented and discussed in detail.

  17. A randomized RSA study concentrating especially on continuous migration.

    Science.gov (United States)

    Molt, Mats; Ryd, Leif; Toksvig-Larsen, Sören

    2016-06-01

    Background and purpose - There is a general call for phased introduction of new implants, and one step in the introduction is an early evaluation of micromotion. We compared the micromotion in the Triathlon and its predecessor, the Duracon total knee prosthesis, concentrating especially on continuous migration over 5 years of follow-up. Patients and methods - 60 patients were randomized to receive either a cemented Triathlon total knee prosthesis or a cemented Duracon total knee prosthesis. 3-D tibial component migration was measured by radiostereometric analysis (RSA) at 3 months and at 1, 2, and 5 years. Results - There was no statistically significant difference in maximum total point motion (MTPM) between the 2 groups (p = 0.1). The mean MTPM at 5 years for the Duracon was 1.10 (SD 1.21) mm and for the Triathlon it was 0.66 (SD 0.38) mm. The numbers of continuously migrating prostheses were similar in the groups at the fifth year of follow-up; 6 of 21 prostheses in the Duracon group and 3 of 21 in the Triathlon group had migrated more than 0.3 mm between the second year and the fifth year of follow-up (p = 0.2). Interpretation - The Triathlon has a micromotion pattern similar to that of the Duracon total knee system at both short-term and medium-term follow-up, and may therefore, over time, show the same good long-term mechanical stability.

  18. The optimization of essential oils supercritical CO2 extraction from Lavandula hybrida through static-dynamic steps procedure and semi-continuous technique using response surface method.

    Science.gov (United States)

    Kamali, Hossein; Aminimoghadamfarouj, Noushin; Golmakani, Ebrahim; Nematollahi, Alireza

    2015-01-01

    The aim of this study was to examine and evaluate crucial variables in essential oils extraction process from Lavandula hybrida through static-dynamic and semi-continuous techniques using response surface method. Essential oil components were extracted from Lavandula hybrida (Lavandin) flowers using supercritical carbon dioxide via static-dynamic steps (SDS) procedure, and semi-continuous (SC) technique. Using response surface method the optimum extraction yield (4.768%) was obtained via SDS at 108.7 bar, 48.5°C, 120 min (static: 8×15), 24 min (dynamic: 8×3 min) in contrast to the 4.620% extraction yield for the SC at 111.6 bar, 49.2°C, 14 min (static), 121.1 min (dynamic). The results indicated that a substantial reduction (81.56%) solvent usage (kg CO2/g oil) is observed in the SDS method versus the conventional SC method.

  19. Continuous mine environmental monitoring system - a case study

    Energy Technology Data Exchange (ETDEWEB)

    Tripathy, D.P.; Sahu, H.B. [Regional Engineering College, Rourkela (India)

    2001-07-01

    The introduction of continuous remote environmental monitoring and control systems in modern coal mines is a great step forward in achieving increased mine safety, higher productivity and effective utilization of manpower. They provide alarms and displays of early warnings and impending dangerous conditions in the mine. They also provide facilities to monitor and control air quality, differential pressure, noise etc. Telemetry systems have distinct advantages over the old tube bundle techniques and are being increasingly used. This article discusses in detail the basic components and the functioning of telemonitoring systems in use with special reference to Colliery A, a degree-1 gassy coal mine worked by the bord and pillar method. The system monitors and processes data on temperature, methane and carbon monoxide. 1 figs., 3 tabs.

  20. Saltstone studies using the scaled continuous processing facility

    Energy Technology Data Exchange (ETDEWEB)

    Fowley, M. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Cozzi, A. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-01

    The Savannah River National Laboratory (SRNL) has supported the Saltstone Facility since its conception with bench-scale laboratory experiments, mid-scale testing at vendor facilities, and consultations and testing at the Saltstone Facility. There have been minimal opportunities for the measurement of rheological properties of the grout slurry at the Saltstone Production Facility (SPF); thus, the Scaled Continuous Processing Facility (SCPF), constructed to provide processing data related to mixing, transfer, and other operations conducted in the SPF, is the most representative process data for determining the expected rheological properties in the SPF. These results can be used to verify the laboratory scale experiments that support the SPF using conventional mixing processes that appropriately represent the shear imparted to the slurry in the SPF.

  1. Surface diffusion studies by optical diffraction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, X.D.

    1992-11-01

    The newly developed optical techniques have been combined with either second harmonic (SH) diffraction or linear diffraction off a monolayer adsorbate grating for surface diffusion measurement. Anisotropy of surface diffusion of CO on Ni(l10) was used as a demonstration for the second harmonic dim reaction method. The linear diffraction method, which possesses a much higher sensitivity than the SH diffraction method, was employed to study the effect of adsorbate-adsorbate interaction on CO diffusion on Ni(l10) surface. Results showed that only the short range direct CO-CO orbital overlapping interaction influences CO diffusion but not the long range dipole-dipole and CO-NI-CO interactions. Effects of impurities and defects on surface diffusion were further explored by using linear diffraction method on CO/Ni(110) system. It was found that a few percent S impurity can alter the CO diffusion barrier height to a much higher value through changing the Ni(110) surface. The point defects of Ni(l10) surface seem to speed up CO diffusion significantly. A mechanism with long jumps over multiple lattice distance initiated by CO filled vacancy is proposed to explain the observed defect effect.

  2. Stream Surface Strip Element Method and Simulation of Three-Dimensional Deformation of Continuous Hot Rolled Strip

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-min; WANG Ying-rui

    2004-01-01

    A new method, the stream surface strip element method, for simulating the three-dimensional deformation of plate and strip rolling process was proposed. The rolling deformation zone was divided into a number of stream surface (curved surface) strip elements along metal flow traces, and the stream surface strip elements were mapped into the corresponding plane strip elements for analysis and computation. The longitudinal distributions of the lateral displacement and the altitudinal displacement of metal were respectively constructed to be a quartic curve and a quadratic curve, of which the lateral distributions were expressed as the third-power spline function, and the altitudinal distributions were fitted in the quadratic curve. From the flow theory of plastic mechanics, the mathematical models of the three-dimensional deformations and stresses of the deformation zone were constructed. Compared with the streamline strip element method proposed by the first author of this paper, the stream surface strip element method takes into account the uneven distributions of stresses and deformations along altitudinal direction, and realizes the precise three-dimensional analysis and computation. The simulation example of continuous hot rolled strip indicates that the method and the model accord with facts and provide a new reliable engineering-computation method for the three-dimensional mechanics simulation of plate and strip rolling process.

  3. Surface chemistry studies of phosphate glasses

    Science.gov (United States)

    Barnes, Amy Suzanne

    This research examined the surface of an undoped and rare-earth doped sodium alumino metaphosphate glass after fracture or surface finishing and subsequent exposure to humid and aqueous environments. In addition, the adsorption of aminopropyl triethoxysilane (APS), and the dominant parameters controlling the structure of the deposited film, were studied. Typically, commercial glasses must be cut and polished into optical components for engineering applications. This process involves a series of aqueous treatments in both acidic and basic media. The experiments performed here on aluminophosphate glass showed that this results in dissolution, surface composition changes (depletion of Na) and surface pitting. In both alkaline detergent and acid etching solution, dissolution at a rate of approximately 4 x 10 -3 mol/m2/hr (0.2 mum/hr) occurs along with a drastic alteration of the surface morphology. When exposed to an environment of elevated humidity and temperature for an extended period of time, this aluminophosphate glass was observed to break down, forming a soluble phosphate gel that dissolves away from the surface. Simultaneously, the surface became enriched in silica, a trace contaminant in the glass, which eventually precipitated and coalesced into a dendritic pattern that covered the surface. The freshly powdered phosphate glass was found to contain surface hydroxyls weakly associated with one another, and some bound by a stronger hydrogen bond, likely to adjacent non-bridging oxygens. Most of these hydroxyls could be desorbed upon heating above the glass transition temperature to leave only a small concentration of weakly associated hydroxyls and free hydroxyls on the surface. The characterization of hydroxyls and water on the phosphate glass surface was used to understand the adsorption of aminopropyl tri-ethoxysilane (APS) also through the use of in-situ DRIFTS. The concentration of adsorbed APS was found to be independent of solution pH, but the measured

  4. Toroidal Continuously Variable Transmission Systems: Terminology and Present Studies

    Directory of Open Access Journals (Sweden)

    Ahmet YILDIZ

    2014-04-01

    Full Text Available The use of continuously variable transmission systems in many different areas such as aerospace, robotics, machinery and automotive industries as an alternative to conventional speed changers with constant ratio becomes widely.Especially in the automotive industry, these systems have been used increasingly, since they enable that internal combustion engines in vehicles run at optimal speeds, and consequently provide considerable fuel savings and therefore lower emission values and also they provide powerful acceleration and quiet working. CVT systems have several constructive variants such as belted, chained, balled, toroidal etc. In this paper, toroidal CVT systems based on elastohydrodynamic principles are concerned with, and fundamental works of last two decades in this field are reviewed. However, the relevant terminology and dynamics along with the control of these systems are briefly treated for better understanding of the literature mentioned. Attention is drawn to the lack of some significant issues in present research works, and potential future works are pointed out. This paper, to the authors’ knowledge, will be the first review on toroidal CVT systems in Turkish literature

  5. Surface science studies of metal hexaborides

    Science.gov (United States)

    Trenary, Michael

    2012-04-01

    Over 30 years of surface science research on metal hexaborides are reviewed. Of this class of compounds, lanthanum hexaboride has been the subject of the majority of the studies because of its outstanding properties as a thermionic emitter. The use of LaB6 cathodes as an electron source stems from the unusually low work function of ~2.5 eV for the (100) surface combined with a low evaporation rate at high temperatures. Of particular interest has been the determination of the surface geometric and electronic structure responsible for the low work function and how the work function is affected by various adsorbates. The low-index faces of single crystals of LaB6 and other hexaborides have been studied with a variety of ultrahigh vacuum surface science methods to gain a better understanding of the structure and properties of the clean surfaces as well as their interactions with gases such as O2, H2O and CO.

  6. Surface science studies of metal hexaborides

    Directory of Open Access Journals (Sweden)

    Michael Trenary

    2012-01-01

    Full Text Available Over 30 years of surface science research on metal hexaborides are reviewed. Of this class of compounds, lanthanum hexaboride has been the subject of the majority of the studies because of its outstanding properties as a thermionic emitter. The use of LaB6 cathodes as an electron source stems from the unusually low work function of ~2.5 eV for the (100 surface combined with a low evaporation rate at high temperatures. Of particular interest has been the determination of the surface geometric and electronic structure responsible for the low work function and how the work function is affected by various adsorbates. The low-index faces of single crystals of LaB6 and other hexaborides have been studied with a variety of ultrahigh vacuum surface science methods to gain a better understanding of the structure and properties of the clean surfaces as well as their interactions with gases such as O2, H2O and CO.

  7. Surface air concentration and deposition of lead-210 in French Guiana: two years of continuous monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Melieres, Marie-Antoinette E-mail: melieres@glaciog.ujf-grenoble.fr; Pourchet, Michel; Richard, Sandrine

    2003-07-01

    To make up for the lack of data on {sup 210}Pb aerosol deposition in tropical regions and to use this radionuclide as an aerosol tracer,a monitoring station was run for two years at Petit-Saut, French Guiana. Lead-210 concentration in air at ground level was monitored continuously together with atmospheric total deposition. The air concentration has a mean value of 0.23{+-}0.02 mBq m{sup -3} during both wet and dry seasons, and it is only weakly affected by the precipitation mechanism. This result was unexpected in a wet tropical region, with a high precipitation rate. In contrast, deposition clearly correlates with precipitation for low/moderate rainfall (<15 cm per 15-day), while this correlation is masked by strong fluctuations at high rainfall. The estimated mean annual deposition over the last ten years is 163{+-}75 Bq m{sup -2} y{sup -1}. This provides a procedure fo estimating this mean flux at other sites in French Guiana.

  8. Semi-continuous, real-time monitoring of protein biomarker using a recyclable surface plasmon resonance sensor.

    Science.gov (United States)

    Kim, Dong-Hyung; Cho, Il-Hoon; Park, Ji-Na; Paek, Sung-Ho; Cho, Hyun-Mo; Paek, Se-Hwan

    2017-02-15

    Although label-free immunosensors based on, for example, surface plasmon resonance (SPR) provide advantages of real-time monitoring of the analyte concentration, its application to routine clinical analysis in a semi-continuous manner is problematic because of the high cost of the sensor chip. The sensor chip is in most cases regenerated by employing an acidic pH. However, this causes gradual deterioration of the activity of the capture antibody immobilized on the sensor surface. To use sensor chips repeatedly, we investigated a novel surface modification method that enables regeneration of the sensor surface under mild conditions. We introduced a monoclonal antibody (anti-CBP Ab) that detects the conformational change in calcium binding protein (CBP) upon Ca(2+) binding (>1mM). To construct a regenerable SPR-based immunosensor, anti-CBP Ab was first immobilized on the sensor surface, and CBP conjugated to the capture antibody (specific for creatine kinase-MB isoform (CK-MB); CBP-CAb) then bound in the presence of Ca(2+). A serum sample was mixed with the detection antibody to CK-MB, which generated an SPR signal proportional to the analyte concentration. After each analysis, the sensor surface was regenerated using medium (pH 7) without Ca(2+), and then adding fresh CBP-CAb in the presence of Ca(2+) for the subsequent analysis. Analysis of multiple samples using the same sensor was reproducible at a rate >98.7%. The dose-response curve was linear for 1.75-500.75ng/mL CK-MB, with an acceptable coefficient of variation of 96%), and exhibited analytical stability for 1 month. To our knowledge, this is the first report of a renewal of a sensor surface with fresh antibody after each analysis, providing high consistency in the assay during a long-term use (e.g., a month at least).

  9. High-efficiency tri-band quasi-continuous phase gradient metamaterials based on spoof surface plasmon polaritons

    Science.gov (United States)

    Li, Yongfeng; Ma, Hua; Wang, Jiafu; Pang, Yongqiang; Zheng, Qiqi; Chen, Hongya; Han, Yajuan; Zhang, Jieqiu; Qu, Shaobo

    2017-01-01

    A high-efficiency tri-band quasi-continuous phase gradient metamaterial is designed and demonstrated based on spoof surface plasmon polaritons (SSPPs). High-efficiency polarizaiton conversion transmission is firstly achieved via tailoring phase differece between the transmisive SSPP and the space wave in orthogonal directions. As an example, a tri-band circular-to-circular (CTC) polarization conversion metamateiral (PCM) was designed by a nonlinearly dispersive phase difference. Using such PCM unit cell, a tri-band quasi-continuous phase gradient metamaterial (PGM) was then realized by virtue of the Pancharatnam-Berry phase. The distribution of the cross-polarization transmission phase along the x-direction is continuous except for two infinitely small intervals near the phases 0° and 360°, and thus the phase gradient has definition at any point along the x-direction. The simulated normalized polarization conversion transmission spectrums together with the electric field distributions for circularly polarized wave and linearly polarized wave demonstrated the high-efficiency anomalous refraction of the quasi-continuous PGM. The experimental verification for the linearly polarized incidence was also provided.

  10. Study Paths, Riemann Surfaces, and Strebel Differentials

    Science.gov (United States)

    Buser, Peter; Semmler, Klaus-Dieter

    2017-01-01

    These pages aim to explain and interpret why the late Mika Seppälä, a conformal geometer, proposed to model student study behaviour using concepts from conformal geometry, such as Riemann surfaces and Strebel differentials. Over many years Mika Seppälä taught online calculus courses to students at Florida State University in the United States, as…

  11. A Continuous Liquid-Level Sensor for Fuel Tanks Based on Surface Plasmon Resonance.

    Science.gov (United States)

    Pozo, Antonio M; Pérez-Ocón, Francisco; Rabaza, Ovidio

    2016-05-19

    A standard problem in large tanks at oil refineries and petrol stations is that water and fuel usually occupy the same tank. This is undesirable and causes problems such as corrosion in the tanks. Normally, the water level in tanks is unknown, with the problems that this entails. We propose herein a method based on surface plasmon resonance (SPR) to detect in real time the interfaces in a tank which can simultaneously contain water, gasoline (or diesel) and air. The plasmonic sensor is composed of a hemispherical glass prism, a magnesium fluoride layer, and a gold layer. We have optimized the structural parameters of the sensor from the theoretical modeling of the reflectance curve. The sensor detects water-fuel and fuel-air interfaces and measures the level of each liquid in real time. This sensor is recommended for inflammable liquids because inside the tank there are no electrical or electronic signals which could cause explosions. The sensor proposed has a sensitivity of between 1.2 and 3.5 RIU(-1) and a resolution of between 5.7 × 10(-4) and 16.5 × 10(-4) RIU.

  12. A Continuous Liquid-Level Sensor for Fuel Tanks Based on Surface Plasmon Resonance

    Science.gov (United States)

    Pozo, Antonio M.; Pérez-Ocón, Francisco; Rabaza, Ovidio

    2016-01-01

    A standard problem in large tanks at oil refineries and petrol stations is that water and fuel usually occupy the same tank. This is undesirable and causes problems such as corrosion in the tanks. Normally, the water level in tanks is unknown, with the problems that this entails. We propose herein a method based on surface plasmon resonance (SPR) to detect in real time the interfaces in a tank which can simultaneously contain water, gasoline (or diesel) and air. The plasmonic sensor is composed of a hemispherical glass prism, a magnesium fluoride layer, and a gold layer. We have optimized the structural parameters of the sensor from the theoretical modeling of the reflectance curve. The sensor detects water-fuel and fuel-air interfaces and measures the level of each liquid in real time. This sensor is recommended for inflammable liquids because inside the tank there are no electrical or electronic signals which could cause explosions. The sensor proposed has a sensitivity of between 1.2 and 3.5 RIU−1 and a resolution of between 5.7 × 10−4 and 16.5 × 10−4 RIU. PMID:27213388

  13. A Continuous Liquid-Level Sensor for Fuel Tanks Based on Surface Plasmon Resonance

    Directory of Open Access Journals (Sweden)

    Antonio M. Pozo

    2016-05-01

    Full Text Available A standard problem in large tanks at oil refineries and petrol stations is that water and fuel usually occupy the same tank. This is undesirable and causes problems such as corrosion in the tanks. Normally, the water level in tanks is unknown, with the problems that this entails. We propose herein a method based on surface plasmon resonance (SPR to detect in real time the interfaces in a tank which can simultaneously contain water, gasoline (or diesel and air. The plasmonic sensor is composed of a hemispherical glass prism, a magnesium fluoride layer, and a gold layer. We have optimized the structural parameters of the sensor from the theoretical modeling of the reflectance curve. The sensor detects water-fuel and fuel-air interfaces and measures the level of each liquid in real time. This sensor is recommended for inflammable liquids because inside the tank there are no electrical or electronic signals which could cause explosions. The sensor proposed has a sensitivity of between 1.2 and 3.5 RIU−1 and a resolution of between 5.7 × 10−4 and 16.5 × 10−4 RIU.

  14. G1 Continuity Conditions of B-spline Surfaces%B样条曲面间的G1连续条件

    Institute of Scientific and Technical Information of China (English)

    车翔玖; 梁学章

    2002-01-01

    According to the B-spline theory and Boehm algorithm, this paper presents severalnecessary and sufficient G1 continuity conditions between two adjacent B-spline surfaces. In orderto meet the need of application, a kind of sufficient conditions of G1 continuity are developed, anda kind of sufficient conditions of G1 continuity among N(N > 2) patch B-spline surfaces meetingat a common corner are given at the end.

  15. Surface-emitting terahertz quantum cascade lasers with continuous-wave power in the tens of milliwatt range

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Gangyi, E-mail: gangyi.xu@mail.sitp.ac.cn [Institut d' Electronique Fondamentale, Univ. Paris Sud, UMR8622 CNRS, 91405 Orsay (France); Key Laboratory of Infrared Imaging Materials and Detectors, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Li, Lianhe; Giles Davies, A.; Linfield, Edmund H. [School of Electronic and Electrical Engineering, University of Leeds, Leeds LS9 2JT (United Kingdom); Isac, Nathalie; Halioua, Yacine; Colombelli, Raffaele, E-mail: raffaele.colombelli@u-psud.fr [Institut d' Electronique Fondamentale, Univ. Paris Sud, UMR8622 CNRS, 91405 Orsay (France)

    2014-03-03

    We demonstrate efficient surface-emitting terahertz frequency quantum cascade lasers with continuous wave output powers of 20–25 mW at 15 K and maximum operating temperatures of 80–85 K. The devices employ a resonant-phonon depopulation active region design with injector, and surface emission is realized using resonators based on graded photonic heterostructures (GPHs). GPHs can be regarded as energy wells for photons and have recently been implemented through grading the period of the photonic structure. In this paper, we show that it is possible to keep the period constant and grade instead the lateral metal coverage across the GPH. This strategy ensures spectrally single-mode operation across the whole laser dynamic range and represents an additional degree of freedom in the design of confining potentials for photons.

  16. Study of hair surface energy and conditioning.

    Science.gov (United States)

    Gao, Timothy; He, Yingxia; Landa, Peter; Tien, Jung-Mei

    2011-01-01

    A new test method has been developed to determine surface energy of hair fibers through measurements of contact angles at two hair/liquid interfaces. By measuring changes in surface energy of the same hair fiber before and after a cosmetic treatment, effects of active ingredients and the performance of tested formulations can be evaluated.The establishment of the method is based on Fowkes theory (1,2) described with two components, a dispersive and a non-dispersive component. The non-polar liquid used in this study was diiodomethane, and the polar liquid was benzyl alcohol. A Kruss 100 Tensiometer was used to measure contact angles of hair fibers. Virgin dark brown and regular bleached hairs were treated with selected conditioner formulations. Reductions in combing forces of hair tresses before and after respective treatments were correlated with decreases in average surface energy of hair fibers obtained from the corresponding tresses.Experimental results indicate that the average surface energy of hair fibers treated with conditioners decreases and the hydrophobicity of the hair surface increases, the results correlate well with the reduction in combing forces after respective treatments. This research work provides a new methodology to evaluate/screen conditioning performance of hair care ingredients and formulations for development of better products.

  17. Sustaining Continuous Improvement: A Longitudinal and Regional Study

    Directory of Open Access Journals (Sweden)

    Henry J. Quesada-Pineda

    2013-09-01

    companies, no changes in perception were found during the period of study for any of the factors. For the other two, however, changes were perceived in at least one of the five constructs in the study. Changes were also found across the regions included. By leveraging the quantitative analysis with qualitative data collected through interviews and visits to the case study companies, we were able to explain the changes in perception and single out the best CI management process to sustain CI in the long term.

  18. Surface and Interface Studies with Radioactive Ions

    CERN Multimedia

    Weber, A

    2002-01-01

    Investigations on the atomic scale of magnetic surfaces and magnetic multilayers were performed by Perturbed Angular Correlation (PAC) spectroscopy. The unique combination of the Booster ISOLDE facility equipped with a UHV beamline and the UHV chamber ASPIC (Apparatus for Surface Physics and Interfaces at CERN) is ideally suited for such microscopic studies. Main advantages are the choice of problem-oriented radioactive probes and the purity of mass-separated beams. The following results were obtained: $\\,$i) Magnetic hyperfine fields (B$_{hf}$) of Se on Fe, Co, Ni surfaces were determined. The results prompted a theoretical study on the B$_{hf}$ values of the 4sp-elements in adatom position on Ni and Fe, confirming our results and predicting unexpected behaviour for the other elements. $\\,$ii) Exemplarily we have determined B$_{hf}$ values of $^{111}$Cd at many different adsorption sites on Ni surfaces. We found a strong dependence on the coordination number of the probes. With decreasing coordination nu...

  19. Business Studies within Design and Technology: Continuity and Progression.

    Science.gov (United States)

    Mathews, Maggie; Swainston, David

    1992-01-01

    Explores the placement of business studies courses within design and technology education programs in the United Kingdom. Reports the sense of isolation felt by business educators. Suggests a progression by which economic concepts could be taught on the various grade levels. Calls for further discussion of the proposal. (SG)

  20. Continuing Personal Professional Development of University Lecturers: A Case Study.

    Science.gov (United States)

    Kapp, C A.; Cilliers, C. D.

    1998-01-01

    A study investigated the design and effectiveness of the faculty development efforts of one University of Stellenbosch (South Africa) faculty member over a two-year period. The experience included use of a professional growth contract to indicate commitment and intention, student feedback from over 500 students in eight courses, structured alumni…

  1. Taking Up Challenges to Surface Engineering by Sci-Tech Advance (Continued)

    Institute of Scientific and Technical Information of China (English)

    Zhang Minsen; Qiu Xianming

    1996-01-01

    @@ Strategy on the Oil/Gas Field Engineering in the Ninth Five-Year Plan Period To study multiphase transportation technology and liquid-liquid hydrocyclone technology For the development of low-permeability oil fields and the oil fields in desert and very shallow sea area, we shall study multiphase transportation technology. These studies will emphasize on multiphase flow behavior and calculation methods, process technology of multiphase transportation, application of multiphase transportation equipment, multiphase meter and its calibration. As most of the oil fields in East China enter the period with medium and high water cut, highly efficient new treatment technology for massive produced liquid needs to be developed urgently. For the development of the oil fields in desert and very shallow sea areas, it is also urgent to develop small-sized, high weight, efficient and reliable oilwater separation technology. The cyclone separation technology needs to be studied, mainly on the flow behavior of the liquid in liquid-liquid cyclone separator and the mechanism of separation, the development of static cyclone and the corollary techniques for liquid-liquid cyclone separation process.

  2. Improvement of Castability and Surface Quality of Continuously Cast TWIP Slabs by Molten Mold Flux Feeding Technology

    Science.gov (United States)

    Cho, Jung-Wook; Yoo, Shin; Park, Min-Seok; Park, Joong-Kil; Moon, Ki-Hyeon

    2016-10-01

    An innovative continuous casting process named POCAST (POSCO's advanced CASting Technology) was developed based on molten mold flux feeding technology to improve both the productivity and the surface quality of cast slabs. In this process, molten mold flux is fed into the casting mold to enhance the thermal insulation of the meniscus and, hence, the lubrication between the solidifying steel shell and the copper mold. Enhancement of both the castability and the surface quality of high-aluminum advanced high-strength steel (AHSS) slabs is one of the most important advantages when the new process has been applied into the commercial continuous casting process. A trial cast of TWIP steel has been carried out using a 10-ton scale pilot caster and 100-ton scale and 250-ton scale commercial casters. The amount of mold flux consumption was more than 0.2 kg/m2 in the new process, which is much larger than that in the conventional powder casting. Trial TWIP castings at both the pilot and the plant caster showed stable mold performances such as mold heat transfer. Also, cast slabs showed periodic/sound oscillation marks and little defects. The successful casting of TWIP steel has been attributed to the following characteristics of POCAST: dilution of the reactant by increasing the slag pool depth, enlargement of channel for slag film infiltration at meniscus by elimination of the slag bear, and decrease of apparent viscosity of the mold slag at meniscus by increasing the slag temperature.

  3. Improvement of Castability and Surface Quality of Continuously Cast TWIP Slabs by Molten Mold Flux Feeding Technology

    Science.gov (United States)

    Cho, Jung-Wook; Yoo, Shin; Park, Min-Seok; Park, Joong-Kil; Moon, Ki-Hyeon

    2017-02-01

    An innovative continuous casting process named POCAST (POSCO's advanced CASting Technology) was developed based on molten mold flux feeding technology to improve both the productivity and the surface quality of cast slabs. In this process, molten mold flux is fed into the casting mold to enhance the thermal insulation of the meniscus and, hence, the lubrication between the solidifying steel shell and the copper mold. Enhancement of both the castability and the surface quality of high-aluminum advanced high-strength steel (AHSS) slabs is one of the most important advantages when the new process has been applied into the commercial continuous casting process. A trial cast of TWIP steel has been carried out using a 10-ton scale pilot caster and 100-ton scale and 250-ton scale commercial casters. The amount of mold flux consumption was more than 0.2 kg/m2 in the new process, which is much larger than that in the conventional powder casting. Trial TWIP castings at both the pilot and the plant caster showed stable mold performances such as mold heat transfer. Also, cast slabs showed periodic/sound oscillation marks and little defects. The successful casting of TWIP steel has been attributed to the following characteristics of POCAST: dilution of the reactant by increasing the slag pool depth, enlargement of channel for slag film infiltration at meniscus by elimination of the slag bear, and decrease of apparent viscosity of the mold slag at meniscus by increasing the slag temperature.

  4. Study of metalloproteins using continuous wave electron paramagnetic resonance (EPR).

    Science.gov (United States)

    Gambarelli, Serge; Maurel, Vincent

    2014-01-01

    Electron paramagnetic resonance (EPR) is an invaluable tool when studying systems with paramagnetic centers. It is a sensitive spectroscopic method, which can be used with dilute samples in aqueous buffer solutions. Here, we describe the basic procedure for recording an X-band EPR spectrum of a metalloprotein sample at low temperature. We also discuss basic optimization techniques to provide spectra with a high signal to noise ratio and minimum distortion.

  5. Treatment of gaseous effluents by using surface discharge plasma in continuous reactors: Process modelling and simulation

    OpenAIRE

    Assadi, Aymen,; Bouzaza, Abdelkrim; Wolbert, Dominique

    2015-01-01

    International audience; In the present work, the oxidation of isovaleraldehyde, a typical pollutant of indoor air, is investigated by using two different plasma DBD reactors: cylindrical and planar reactor. The study of the influence of the specific energy shows that its increment is accompanied by an increase of the removal efficiency. In fact, when specific energy extends three times, the removal efficiency is increased from 5 to 40%. Moreover an increase of the specific energy induces a hi...

  6. Treatment of gaseous effluents by using surface discharge plasma in continuous reactors: Process modelling and simulation

    OpenAIRE

    Assadi, Aymen; Bouzaza, Abdelkrim; Wolbert, Dominique

    2015-01-01

    International audience; In the present work, the oxidation of isovaleraldehyde, a typical pollutant of indoor air, is investigated by using two different plasma DBD reactors: cylindrical and planar reactor. The study of the influence of the specific energy shows that its increment is accompanied by an increase of the removal efficiency. In fact, when specific energy extends three times, the removal efficiency is increased from 5 to 40%. Moreover an increase of the specific energy induces a hi...

  7. A study of different supports for the catalytic reduction of nitrates from natural water with a continuous reactor

    OpenAIRE

    Palomares, A.E.; Franch, C.; Corma,A.

    2011-01-01

    The aim of this work is to study the activity for the nitrate catalytic reduction in natural water, using a continuous stirred tank reactor, of Pd/Cu and Pd/Sn catalysts supported on different materials. The studied supports are: -Al2O3 (commercial), active carbon, graphite, hydrotalcite and alumina synthesized in our laboratory with a high surface area. The activity and selectivity of the catalysts supported on these materials have been compared. The best results have been obtain...

  8. Surface and Mechanical studies of Bismaleimide coatings

    OpenAIRE

    Bhattacharyya, A. S.; Paul, D; Dutta, P. P.; Bhattacharjee, G.

    2015-01-01

    Bismaleimide (BMI) resins are a new breed of thermosetting resins used mainly for high temperature applications and have major usage in aerospace. BMI polymer coatings were deposited on aluminum and mild steel substrates. The effect of corrosion on mild steel and aluminum by Ringers Solution and there protection using BMI coatings were observed. X-ray diffraction studies showed crystalline nature of the BMI coatings. Surface contact angle measurements were carried out using goniometer.

  9. Mapping the land surface for global atmosphere-biosphere models: Toward continuous distributions of vegetation's functional properties

    Science.gov (United States)

    Defries, Ruth S.; Field, Christopher B.; Fung, Inez; Justice, Christopher O.; Los, Sietse; Matson, Pamela A.; Matthews, Elaine; Mooney, Harold A.; Potter, Christopher S.; Prentice, Katharine; Sellers, Piers J.; Townshend, John R. G.; Tucker, Compton J.; Ustin, Susan L.; Vitousek, Peter M.

    1995-10-01

    Global land surface characteristics are important boundary conditions for global models that describe exchanges of water, energy, and carbon dioxide between the atmosphere and biosphere. Existing data sets of global land cover are based on classification schemes that characterize each grid cell as a discrete vegetation type. Consequently, parameter fields derived from these data sets are dependent on the particular scheme and the number of vegetation types it includes. The functional controls on exchanges of water, energy, and carbon dioxide between the atmosphere and biosphere are now well enough understood that it is increasingly feasible to model these exchanges using a small number of vegetation characteristics that either are related to or closely related to the functional controls. Ideally, these characteristics would be mapped as continuous distributions to capture mixtures and gradients in vegetation within the cell size of the model. While such an approach makes it more difficult to build models from detailed observations at a small number of sites, it increases the potential for capturing functionally important variation within, as well as between, vegetation types. Globally, the vegetation characteristics that appear to be most important in controlling fluxes of water, energy, and carbon dioxide include (1) growth form (tree, shrub, herb), (2) seasonality of woody vegetation (deciduous, evergreen), (3) leaf type (broadleaf, coniferous), (4) photosynthetic pathway of nonwoody vegetation (C3, C4), (5) longevity (annual, perennial), and (6) type and intensity of disturbance (e.g., cultivation, fire history). Many of these characteristics can be obtained through remote sensing, though some require ground-based information. The minimum number and the identity of the required land surface characteristics almost certainly vary with the intended objective, but the philosophy of driving models with continuous distributions of a small number of land surface

  10. Surface coating for flame-retardant behavior of cotton fabric using a continuous layer-by-layer process

    Science.gov (United States)

    Cotton’s exceptional softness, breathability, and absorbency have made it America’s best selling textile fiber; however, cotton textiles are generally more combustible than their synthetic counterparts. In this study, a continuous layer-by-layer self-assembly technique was used to deposit polymer-cl...

  11. Meaning and Semantics of Surface Continuity%曲面连续性及其形态语义

    Institute of Scientific and Technical Information of China (English)

    张欣; 唐瑶瑶

    2011-01-01

    根据曲面连续性在产品设计中的广泛应用为启示,分析了曲面连续形式的界定、分类、视觉感受及实用价值,并结合自然生物形式案例、设计史知识及符号学理论,论述了曲面连续形式的语意来源,进而又分析了多连续性形式进化所引发的语意变化及对产品风格的影响。在此基础上,提出将连续性形式语意描述应用于实践,能有利于设计过程的延续和行动反恩的强化,是引导进一步探索的有效方式。%It analyzed the definition, classification, visual experience and practical value of surface continuity in product design according to wide application of it. With the help of relative nature forms, design history knowledge and semeiotics theory, it proposed semantic sources of curved continuous forms, and then explored the meaning change of form evolution in multi-continuity. Multi-continuity forms had certain economic value and aesthetic value, it is an important design basis of high quality products. The application of semantics description in practice can be beneficial to design process. It will strengthen reflection-in-action and be an effective guide to further inquiry.

  12. Surface properties of a single perfluoroalkyl group on water surfaces studied by surface potential measurements.

    Science.gov (United States)

    Shimoaka, Takafumi; Tanaka, Yuki; Shioya, Nobutaka; Morita, Kohei; Sonoyama, Masashi; Amii, Hideki; Takagi, Toshiyuki; Kanamori, Toshiyuki; Hasegawa, Takeshi

    2016-12-01

    A discriminative study of a single perfluoroalkyl (Rf) group from a bulk material is recently recognized to be necessary toward the total understanding of Rf compounds based on a primary chemical structure. The single molecule and the bulk matter have an interrelationship via an intrinsic two-dimensional (2D) aggregation property of an Rf group, which is theorized by the stratified dipole-arrays (SDA) theory. Since an Rf group has dipole moments along many C-F bonds, a single Rf group would possess a hydrophilic-like character on the surface. To reveal the hydration character of a single Rf group, in the present study, surface potential (ΔV) measurements are performed for Langmuir monolayers of Rf-containing compounds. From a comparative study with a monolayer of a normal hydrocarbon compound, the hydration/dehydration dynamics of a lying Rf group on water has first been monitored by ΔV measurements, through which a single Rf group has been revealed to have a unique "dipole-interactive" character, which enables the Rf group interacted with the water 'surface.' In addition, the SDA theory proves to be useful to predict the 2D aggregation property across the phase transition temperature of 19°C by use of the ΔV measurements.

  13. Mathematics Teachers' Perception of Lesson Study as a Continuous Professional Development Programme

    Science.gov (United States)

    bin Hj Suhaili, Hj Ade Shahren; Khalid, Madihah

    2011-01-01

    Lesson Study can be viewed as a continuous development programme because it offers teachers support in an environment unlike other traditional continuous development programmes. In this study, 28 primary mathematics teachers were surveyed and 4 out of the 28 were interviewed to examine how they perceived Lesson Study as professional development.…

  14. Continuous acoustic studies of overwintering sprat Sprattus sprattus reveal flexible behavior

    KAUST Repository

    Solberg, I

    2012-09-19

    The clupeid fish Sprattus sprattus was studied in a 150 m deep Norwegian fjord throughout an entire overwintering period during which the fjord froze over and a major water renewal occurred. A bottom-mounted (upward-facing) echosounder provided continuous high-resolution data and enabled studies of swimming speed and behavior of individual sprat in addition to population behavior. The continuous acoustic studies were supplemented with intermittent field campaigns. The sprat displayed different behavioral modes with changing environmental conditions. During the first part of the winter, the majority of the population occurred in deep waters during both day and night, yet exhibited a shallower night-time distribution. Individual sprat swam alternately up and down, a ‘rise and sink’ behavior likely a compensation for negative buoyancy because of swim bladder compression. Because feeding was negligible in deep waters, the swimming pattern was not inferred as prey search behavior. Another part of the population schooled at shallower depths during the day and carried out vertical migration to upper waters at night. However, individuals were observed as they switched between these behavioral groups. A sudden change in both swimming behavior and vertical distribution occurred as the fjord became ice covered. Near-bottom ‘rise and sink’ swimming was replaced by schooling in mid-water during the day, and the sprat aggregated in dense layers near the surface at night. We suggest that the ice made the sprat shift their antipredator strategy from hiding at depth to hiding in schools in the darker waters below the ice. This long-term acoustic study has shown that sprat have a flexible behavioral repertoire, displaying different overwintering strategies within a population, depending on environmental conditions.

  15. Continuous-flow microfluidic blood cell sorting for unprocessed whole blood using surface-micromachined microfiltration membranes.

    Science.gov (United States)

    Li, Xiang; Chen, Weiqiang; Liu, Guangyu; Lu, Wei; Fu, Jianping

    2014-07-21

    White blood cells (WBCs) constitute about 0.1% of the blood cells, yet they play a critical role in innate and adaptive immune responses against pathogenic infections, allergic conditions, and malignancies and thus contain rich information about the immune status of the body. Rapid isolation of WBCs directly from whole blood is a prerequisite for any integrated immunoassay platform designed for examining WBC phenotypes and functions; however, such functionality is still challenging for blood-on-a-chip systems, as existing microfluidic cell sorting techniques are inadequate for efficiently processing unprocessed whole blood on chip with concurrent high throughput and cell purity. Herein we report a microfluidic chip for continuous-flow isolation and sorting of WBCs from whole blood with high throughput and separation efficiency. The microfluidic cell sorting chip leveraged the crossflow filtration scheme in conjunction with a surface-micromachined poly(dimethylsiloxane) (PDMS) microfiltration membrane (PMM) with high porosity. With a sample throughput of 1 mL h(-1), the microfluidic cell sorting chip could recover 27.4 ± 4.9% WBCs with a purity of 93.5 ± 0.5%. By virtue of its separation efficiency, ease of sample recovery, and high throughput enabled by its continuous-flow operation, the microfluidic cell sorting chip holds promise as an upstream component for blood sample preparation and analysis in integrated blood-on-a-chip systems.

  16. Drag Force of Non-newtonian Fluid on a Continuous Moving Surface with Strong Suction/Blowing

    Institute of Scientific and Technical Information of China (English)

    郑连存; 张欣欣; 赫冀成

    2003-01-01

    A theoretical analysis for the laminar boundary layer flow of a non-Newtonian fluid on a continuous moving flat plate with surface strong suction/blowing is made. The types of potential flows necessary for similar solutions to the boundary layer are determined and both analytical and numerical solutions are presented. It is shown that the solution of the boundary layer problem depends not only on the ratio of the velocity of the plate to the velocity of the free stream, but also on the suction/blowing parameter. The skin friction decreases with increasing the parameters of power law and blowing. In the case of existing suction, the shear force decreases with the increases of tangential velocity, the largest shear force occurs at wall and the smallest shear force occurs at the edge of the boundary layer. However, in the case of existing surface blowing, the shear force initially increases with tangentialvelocity and the biggest shear force occurs at the interior of the boundary layer, the skin friction approaches to zero as the blowing rate approaches the critical value.

  17. A KINEMATIC STUDY OF FINSWIMMING AT SURFACE

    Directory of Open Access Journals (Sweden)

    Pier-Giorgio Zanone

    2004-06-01

    Full Text Available Finswimming is a sport of speed practiced on the surface or underwater, in which performance is based on whole-body oscillations. The present study investigated the undulatory motion performed by finswimmers at the surface. This study aiming to analyze the influence of the interaction of gender, practice level, and race distance on selected kinematic parameters. Six elite and six novices finswimmers equipped with joints markers (wrist, elbow, shoulder, hip, knee, and ankle were recorded in the sagittal plane. The position of these anatomical marks was digitized at 50 Hz. An automated motion analysis software yielded velocity, vertical amplitude, frequency, and angular position. Results showed that stroke frequency decreased whereas the mean amplitude of all joints increased with increasing race distance (p < 0.01. Mean joint amplitude for the upper limbs (wrist, elbow and shoulder was smaller for experts than for novices. Whereas that of the ankle was larger, so that the oscillation amplitude increased from shoulder to ankle. Elite male finswimmers were pitching more acutely than female. Moreover, elite male finswimmers showed a smaller knee bending than novices and than elite females (p < 0.01. This indicated that elite male finswimmers attempt to reduce drag forces thanks to a weak knee bending and a low upper limbs pitch. To sum up, gender, expertise, and race distance affect the performance and its kinematics in terms frontal drag. Expertise in finswimming requires taking advantage of the mechanical constraints pertaining to hydrodynamic constraints in order to optimize performance

  18. Polylactide/acetylated nanocrystalline cellulose composites prepared by a continuous route: A phase interface-property relation study.

    Science.gov (United States)

    Xu, Chunjiang; Chen, Jianxiang; Wu, Defeng; Chen, Yang; Lv, Qiaolian; Wang, Mengqi

    2016-08-01

    A 'continuous route' was developed in this work for the preparation of nanocrystalline cellulose (NCC) filled polylactide (PLA) composites. It combines several separated steps, including extraction of NCC, surface acetylation of NCC, and final composite preparation, into a continuous process, without traditional freeze drying. The obtained PLA composites were then studied in terms of phase interface structure, rheological and mechanical properties. The results reveal that surface acetylation of NCC can improve its affinity to PLA evidently. The thickened interfacial layer makes the system filled with modified NCC show lower percolation threshold than the one filled with pristine NCC; and the former presents a typical strain-scaling stress overshoot behavior in the start-up shear flow because the network structure of modified NCC presents stronger characteristics of self-similarity. The phase interface adhesion also plays an important role in the mechanical behavior of PLA/NCC composites, which is further revealed by the nanomechanical analysis using atom force microscopy.

  19. Wettability studies of topologically distinct titanium surfaces.

    Science.gov (United States)

    Kulkarni, Mukta; Patil-Sen, Yogita; Junkar, Ita; Kulkarni, Chandrashekhar V; Lorenzetti, Martina; Iglič, Aleš

    2015-05-01

    Biomedical implants made of titanium-based materials are expected to have certain essential features including high bone-to-implant contact and optimum osteointegration, which are often influenced by the surface topography and physicochemical properties of titanium surfaces. The surface structure in the nanoscale regime is presumed to alter/facilitate the protein binding, cell adhesion and proliferation, thereby reducing post-operative complications with increased lifespan of biomedical implants. The novelty of our TiO2 nanostructures lies mainly in the high level control over their morphology and roughness by mere compositional change and optimisation of the experimental parameters. The present work focuses on the wetting behaviour of various nanostructured titanium surfaces towards water. Kinetics of contact area of water droplet on macroscopically flat, nanoporous and nanotubular titanium surface topologies was monitored under similar evaporation conditions. The contact area of the water droplet on hydrophobic titanium planar surface (foil) was found to decrease during evaporation, whereas the contact area of the droplet on hydrophobic nanorough titanium surfaces practically remained unaffected until the complete evaporation. This demonstrates that the surface morphology and roughness at the nanoscale level substantially affect the titanium dioxide surface-water droplet interaction, opposing to previous observations for microscale structured surfaces. The difference in surface topographic nanofeatures of nanostructured titanium surfaces could be correlated not only with the time-dependency of the contact area, but also with time-dependency of the contact angle and electrochemical properties of these surfaces.

  20. Physicochemical Studies of the Sea Surface Microlayer.

    Science.gov (United States)

    Zhengbin; Liansheng; Zhijian; Jun; Haibing

    1998-08-15

    The sea surface microlayer and its thickness are theoretically analyzed. A multiple-layer model of the sea surface microlayer is proposed. Through in situ and laboratory imitation experiments using glass plate, rotating drum, screen, and funnel samplers, the relationships between pH, surface tension, the concentrations of dissolved trace metals Cu and Pb, phosphate, and particulate and sampling thicknesses are carefully investigated. The apparent sampling thickness of the sea surface microlayer is determined to be 50 +/- 10 µm, which is basically consistent with the mean thickness of the liquid boundary film in the models of gas exchange across the sea surface. Copyright 1998 Academic Press.

  1. Structural and spectroscopic studies of surfaces

    CERN Document Server

    Laitenberger, P

    1996-01-01

    and on a 10ML thick Ar spacer layer, a remarkable substrate dependence is revealed. A new STM-based technique for fabricating simple metal-structures with dimensions in the 10-100nm regime which are partially electrically isolated from their environment was developed in collaboration with Dr. L. A. Silva. This technique employs the STM tip as a mechanical nanofabrication tool to machine gaps into a thin metallic film deposited on an insulating substrate, which laterally confine and electrically isolate the desired metal regions. Several metal structures, such as nanoscale wires and pads, were successfully created. Finally, the conceptual basis and present stage of construction of a new surface analytical tool, the Scanning Probe Energy Loss Spectrometer (SPELS), is discussed. The SPELS offers the exciting prospect of collecting structural as well as spectroscopic information with a spatial resolution of a few nanometres. Once successfully developed, it will be ideally suited for spectroscopic studies of nanos...

  2. The optimization of essential oils supercritical CO 2 extraction from Lavandula hybrida through static-dynamic steps procedure and semi-continuous technique using response surface method

    Directory of Open Access Journals (Sweden)

    Hossein Kamali

    2015-01-01

    Full Text Available Aim: The aim of this study was to examine and evaluate crucial variables in essential oils extraction process from Lavandula hybrida through static-dynamic and semi-continuous techniques using response surface method. Materials and Methods: Essential oil components were extracted from Lavandula hybrida (Lavandin flowers using supercritical carbon dioxide via static-dynamic steps (SDS procedure, and semi-continuous (SC technique. Results: Using response surface method the optimum extraction yield (4.768% was obtained via SDS at 108.7 bar, 48.5° C , 120 min (static: 8×15, 24 min (dynamic: 8×3 min in contrast to the 4.620% extraction yield for the SC at 111.6 bar, 49.2° C , 14 min (static, 121.1 min (dynamic. Conclusion: The results indicated that a substantial reduction (81.56% solvent usage (kg CO 2 /g oil is observed in the SDS method versus the conventional SC method.

  3. A longitudinal study of temperament continuity through IBQ, TBAQ and CBQ.

    Science.gov (United States)

    Carranza, José Antonio; González-Salinas, Carmen; Ato, Ester

    2013-12-01

    The aim of this work was to study the continuity of temperament in a Spanish sample (n = 60), covering the developmental stages of infancy, toddlerhood and childhood. Temperamental dimensions showed, with few exceptions, as much homotypic as heterotypic continuity as was to be expected. At the level of latent superconstructs continuity, we found that Anger and Fear followed different developmental paths and showed continuity over all the periods evaluated. Positive Affect/Regulation superconstruct showed continuity from infancy to toddlerhood. From toddlerhood, Positive Affect/Regulation showed continuity with the superconstruct of Effortful Control but not with the superconstruct of Surgency/Extraversion. At an ipsative level, we found two groups of subjects, labeled 'nonexpressive/controlled' and 'noncontrolled/expressive'. Generally, these results confirm the stability of temperament in the periods analyzed and underline the importance of toddlerhood as a transitional period in the maturity of self-regulatory capabilities shown in childhood.

  4. Spatiotemporal Dynamics of Surface Water Extent from Three Decades of Seasonally Continuous Landsat Time Series at Subcontinental Scale

    Science.gov (United States)

    Tulbure, M. G.; Broich, M.; Stehman, Stephen V.

    2016-06-01

    Surface water is a critical resource in semi-arid areas. The Murray-Darling Basin (MDB) of Australia, one of the largest semi-arid basins in the world is aiming to set a worldwide example of how to balance multiple interests (i.e. environment, agriculture and urban use), but has suffered significant water shrinkages during the Millennium Drought (1999-2009), followed by extensive flooding. Baseline information and systematic quantification of surface water (SW) extent and flooding dynamics in space and time are needed for managing SW resources across the basin but are currently lacking. To synoptically quantify changes in SW extent and flooding dynamics over MDB, we used seasonally continuous Landsat TM and ETM+ data (1986 - 2011) and generic machine learning algorithms. We further mapped flooded forest at a riparian forest site that experienced severe tree dieback due to changes in flooding regime. We used a stratified sampling design to assess the accuracy of the SW product across time. Accuracy assessment yielded an overall classification accuracy of 99.94%, with producer's and user's accuracy of SW of 85.4% and 97.3%, respectively. Overall accuracy was the same for Landsat 5 and 7 data but user's and producer's accuracy of water were higher for Landsat 7 than 5 data and stable over time. Our validated results document a rapid loss in SW bodies. The number, size, and total area of SW showed high seasonal variability with highest numbers in winter and lowest numbers in summer. SW extent per season per year showed high interannual and seasonal variability, with low seasonal variability during the Millennium Drought. Examples of current uses of the new dataset will be presented and include (1) assessing ecosystem response to flooding with implications for environmental water releases, one of the largest investment in environment in Australia; (2) quantifying drivers of SW dynamics (e.g. climate, human activity); (3) quantifying changes in SW dynamics and

  5. Transcranial direct current stimulation in refractory continuous spikes and waves during slow sleep: a controlled study

    DEFF Research Database (Denmark)

    Varga, Edina T; Terney, Daniella; Atkins, Mary D

    2011-01-01

    Cathodal transcranial direct current stimulation (tDCS) decreases cortical excitability. The purpose of the study was to investigate whether cathodal tDCS could interrupt the continuous epileptiform activity. Five patients with focal, refractory continuous spikes and waves during slow sleep were ...

  6. Almost All Start but Who Continue? A Longitudinal Study of Youth Participation in Swedish Club Sports

    Science.gov (United States)

    Jakobsson, Britta Thedin; Lundvall, Suzanne; Redelius, Karin; Engstrom, Lars-Magnus

    2012-01-01

    Many young people in Sweden stop participating in club sports during their teens, but some continue. Drawing on a longitudinal study, the aim of this article is to highlight some of the characteristics of teenagers who continue with club sports and to discuss the relation between club-sport participation and social and cultural conditions, with…

  7. Surface-induced ordering and disordering in face-centered-cubic alloys: A Monte Carlo study

    Science.gov (United States)

    Schweika, W.; Landau, D. P.; Binder, K.

    1996-04-01

    Using extensive Monte Carlo simulations we have studied phase transitions in a fcc model with antiferromagnetic nearest-neighbor couplings J in the presence of different free surfaces which lead either to surface-induced order or to surface-induced disorder. Our model is a prototype for CuAu-type ordering alloys and shows a strong first-order bulk transition at a temperature kTcb/||J||=1.738 005(50). For free (100) surfaces, we find a continuous surface transition at a temperature Tcs>~Tcb exhibiting critical exponents of the two-dimensional Ising model. Surface-induced ordering occurs as the temperature approaches Tcb and the surface excess order and surface excess energy diverges logarithmically. For a free (111) surface, the surface order vanishes continuously at Tcb accompanied by surface-induced disorder (SID). In addition to a logarithmic divergence of the excess quantities of order and energy, we find further critical exponents which confirm the actual theory of SID and critical wetting and which can be understood in terms of rough interfaces. For both cases of free surfaces, the asymptotic behavior of the squared interfacial width shows the expected logarithmic divergence.

  8. Cavitation control on a 2D hydrofoil through a continuous tangential injection of liquid: Experimental study

    Science.gov (United States)

    Timoshevskiy, M. V.; Zapryagaev, I. I.; Pervunin, K. S.; Markovich, D. M.

    2016-10-01

    In the paper, the possibility of active control of a cavitating flow over a 2D hydrofoil that replicates a scaled-down model of high-pressure hydroturbine guide vane (GV) was tested. The flow manipulation was implemented by a continuous tangential liquid injection at different flow rates through a spanwise slot in the foil surface. In experiments, the hydrofoil was placed in the test channel at the attack angle of 9°. Different cavitation conditions were reached by varying the cavitation number and injection velocity. In order to study time dynamics and spatial patterns of partial cavities, high-speed imaging was employed. A PIV method was used to measure the mean and fluctuating velocity fields over the hydrofoil. Hydroacoustic measurements were carried out by means of a pressure transducer to identify spectral characteristics of the cavitating flow. It was found that the present control technique is able to modify the partial cavity pattern (or even totally suppress cavitation) in case of stable sheet cavitation and change the amplitude of pressure pulsations at unsteady regimes. The injection technique makes it also possible to significantly influence the spatial distributions of the mean velocity and its turbulent fluctuations over the GV section for non-cavitating flow and sheet cavitation.

  9. An Application Study of Transition Surface Reconstruction in Reverse Engineering

    Institute of Scientific and Technical Information of China (English)

    LUJing-ping; HEYu-lin; LIAOXiao-ping

    2004-01-01

    the reconstruction of transition surface is one of time consuming activities during surface modeling in reverse engineering. Yet currently available software applications suffer from shortcoming in processing the connection among free form surfaces. In this paper, a new method is put forward combining Surfacer with Unigraphics to resolve this problem: Curves and surfaces are first constructed in Surfacer, then, the finished data is imported into Unigraphics based on IGES format. At last, the transition surface can be reconstructed in Unigraphics. The application of this method in transition surface reconstruction is illustrated by means of two case studies,showing the connection between free form surfaces; filleting and rounding among multiple surfaces; transition surface between two sets of surfaces.

  10. Older adults' attitudes about continuing cancer screening later in life: a pilot study interviewing residents of two continuing care communities

    Directory of Open Access Journals (Sweden)

    Walter Louise C

    2006-08-01

    Full Text Available Abstract Background Individualized decision making has been recommended for cancer screening decisions in older adults. Because older adults' preferences are central to individualized decisions, we assessed older adults' perspectives about continuing cancer screening later in life. Methods Face to face interviews with 116 residents age 70 or over from two long-term care retirement communities. Interview content included questions about whether participants had discussed cancer screening with their physicians since turning age 70, their attitudes about information important for individualized decisions, and their attitudes about continuing cancer screening later in life. Results Forty-nine percent of participants reported that they had an opportunity to discuss cancer screening with their physician since turning age 70; 89% would have preferred to have had these discussions. Sixty-two percent believed their own life expectancy was not important for decision making, and 48% preferred not to discuss life expectancy. Attitudes about continuing cancer screening were favorable. Most participants reported that they would continue screening throughout their lives and 43% would consider getting screened even if their doctors recommended against it. Only 13% thought that they would not live long enough to benefit from cancer screening tests. Factors important to consider stopping include: age, deteriorating or poor health, concerns about the effectiveness of the tests, and doctors recommendations. Conclusion This select group of older adults held positive attitudes about continuing cancer screening later in life, and many may have had unrealistic expectations. Individualized decision making could help clarify how life expectancy affects the potential survival benefits of cancer screening. Future research is needed to determine whether educating older adults about the importance of longevity in screening decisions would be acceptable, affect older adults

  11. Preliminary results of continuous GPS monitoring of surface deformation at the Aquistore underground CO2 storage site

    Science.gov (United States)

    Craymer, M. R.; Henton, J. A.; Piraszewski, M.; Silliker, J.; Samsonov, S. V.

    2013-12-01

    Aquistore is a demonstration project for the underground storage of CO2 at a depth of ~3350 m near Estevan, Saskatchewan, Canada. An objective of the project is to design, adapt, and test non-seismic monitoring methods that have not been systematically utilized to date for monitoring CO2 storage projects, and to integrate the data from these various monitoring tools to obtain quantitative estimates of the change in subsurface fluid distributions, pressure changes and associated surface deformation. Monitoring methods being applied include satellite-, surface- and wellbore-based monitoring systems and comprise natural- and controlled-source electromagnetic methods, gravity monitoring, GPS, synthetic aperture radar interferometry (InSAR), tiltmeter array analysis, and chemical tracer studies. Here we focus on the GPS monitoring of surface deformation. Five of the planned thirteen GPS monitoring stations were installed in November 2012 and results subsequently processed on a weekly basis. The first GPS results prior to CO2 injection have just been determined using both precise point positioning (PPP) and baseline processing with the Bernese GPS Software. The time series of the five sites are examined, compared and analysed with respect to monument stability, seasonal signals and estimates of expected regional ground motion. The individual weekly network solutions are combined together in a cumulative 4D network solution to provide a preliminary local velocity field in the immediately vicinity of the injection well. The results are compared to those from InSAR.

  12. Continuation of cinacalcet immediately after renal transplantation: a prospective cohort study.

    NARCIS (Netherlands)

    Aalten, J.; Wetzels, J.F.M.; Hoitsma, A.J.

    2010-01-01

    BACKGROUND: cinacalcet is used for treating secondary hyperparathyroidism in dialysis patients, but it is currently unknown whether it can safely be continued immediately after renal transplantation. METHODS: we prospectively studied renal transplant recipients with secondary hyperparathyroidism who

  13. An action research study; cultural differences impact how manufacturing organizations receive continuous improvement

    Science.gov (United States)

    Kattman, Braden R.

    National culture and organizational culture impact how continuous improvement methods are received, implemented and deployed by suppliers. Previous research emphasized the dominance of national culture over organizational culture. The countries studied included Poland, Mexico, China, Taiwan, South Korea, Estonia, India, Canada, the United States, the United Kingdom, and Japan. The research found that Canada was most receptive to continuous improvement, with China being the least receptive. The study found that organizational culture was more influential than national culture. Isomorphism and benchmarking is driving continuous-improvement language and methods to be more universally known within business. Business and management practices are taking precedence in driving change within organizations.

  14. Two Conceptual Approaches For The Continuous Time Computation of Infiltration and Surface Runoff In Spatially Distributed Rainfall-runoff Models

    Science.gov (United States)

    Brath, A.; Crosta, G.; Frattini, P.; Montanari, A.; Moretti, G.

    Distributed rainfall-runoff models are often applied for performing hydrological sim- ulations extended to the time span of single flood events, in order to limit the compu- tational effort. The increasing availability of computing powers makes now possible to move towards standard techniques for flood hydrograph estimation based upon the application of continuous simulation distributed models. These allow to perform hy- drological analyses that would be not possible by using lumped models, such as, for instance, the assessment of the effects on river discharges of spatially distributed land- use changes. In order to perform spatially-distributed and continuous time hydrologi- cal simulations, one has to represent the infiltration process at the local scale by using schemes which are capable of simulating the soil water content redistribution during the interstorm periods. To this end, the present study aims at presenting an application of two conceptual schemes, which have been derived by modifying the event-based Green-Ampt and Curve Number infiltration models. The proposed approaches have been embedded in a spatially distributed, DEM-based, rainfall-runoff model. An ap- plication of the model is presented, that refers to a river basin located in Northern Italy.

  15. Cultural continuity, traditional Indigenous language, and diabetes in Alberta First Nations: a mixed methods study.

    Science.gov (United States)

    Oster, Richard T; Grier, Angela; Lightning, Rick; Mayan, Maria J; Toth, Ellen L

    2014-10-19

    We used an exploratory sequential mixed methods approach to study the association between cultural continuity, self-determination, and diabetes prevalence in First Nations in Alberta, Canada. We conducted a qualitative description where we interviewed 10 Cree and Blackfoot leaders (members of Chief and Council) from across the province to understand cultural continuity, self-determination, and their relationship to health and diabetes, in the Alberta First Nations context. Based on the qualitative findings, we then conducted a cross-sectional analysis using provincial administrative data and publically available data for 31 First Nations communities to quantitatively examine any relationship between cultural continuity and diabetes prevalence. Cultural continuity, or "being who we are", is foundational to health in successful First Nations. Self-determination, or "being a self-sufficient Nation", stems from cultural continuity and is seriously compromised in today's Alberta Cree and Blackfoot Nations. Unfortunately, First Nations are in a continuous struggle with government policy. The intergenerational effects of colonization continue to impact the culture, which undermines the sense of self-determination, and contributes to diabetes and ill health. Crude diabetes prevalence varied dramatically among First Nations with values as low as 1.2% and as high as 18.3%. Those First Nations that appeared to have more cultural continuity (measured by traditional Indigenous language knowledge) had significantly lower diabetes prevalence after adjustment for socio-economic factors (p =0.007). First Nations that have been better able to preserve their culture may be relatively protected from diabetes.

  16. Effects of continuous cover forestry on soil moisture pattern - Beginning steps of a Hungarian study

    Science.gov (United States)

    Kalicz, Péter; Bartha, Dénes; Brolly, Gábor; Csáfordi, Péter; Csiszár, Ágnes; Eredics, Attila; Gribovszki, Zoltán; Király, Géza; Kollár, Tamás; Korda, Márton; Kucsara, Mihály; Nótári, Krisztina; Kornél Szegedi, Balázs; Tiborcz, Viktor; Zagyvai, Gergely; Zagyvai-Kiss, Katalin Anita

    2014-05-01

    Nowadays Hungarian foresters encounter a new challenge. The traditional management practices do not meet anymore with the demand of the civil society. The good old clearcut is no more a supported technology in forest regeneration. The transition to the continuous cover forestry induces much higher spatial variability compared to the even aged, more or less homogeneous, monoculture stands. The gap cutting is one of the proposed key methods in the Hungarian forestry. There is an active discussion among forest professionals how to determine the optimal gap size to maintain ideal conditions for the seedlings. Among other open questions for example how the surrounding trees modify the moisture pattern of the forest floor in the gap? In the early steps of a multidisciplinary project we established four research plots to study the spatial and temporal variability of soil moisture in the forest gap and the surrounding undisturbed stand. Each plot is located in oak (Quercus spp.) stands. Natural regeneration of oak stands is more problematic in our climate compared to the beech (Fagus sylvatica) which is located in the more humid or semi-humid areas of our country. All plots are located in the western part of Hungary: close to Sopron, Bejcgyertyános, Vép and Vajszló settlements. The last plot is an extensive research area, which is located in the riparian zone of a tributary of Feketevíz River. We monitor here the close-to-surface groundwater level fluctuation with pressure transducers. With a diurnal fluctuation based method it is possible to quantify the evapotranspiration differences between the gap and the stand. In two of the remaining stands (Bejcgyertyános and Vép) the gaps were opened in 2010. The monitoring of soil moisture began in 2013. A mobile sensor is used to monitor soil-moisture in a regular grid. The spatial variability of soil-moisture time-series shows a characteristic pattern during the growing-season. The plot in Sopron was established in 2013

  17. Feasibility Studies on Underwater Laser Surface Hardening Process

    OpenAIRE

    Biao Jin; Min Li; TaeWoo Hwang; YoungHoon Moon

    2015-01-01

    Laser surface hardening process is a very promising hardening method for ferrous and nonferrous alloys where transformations occur during cooling after laser melting in the solid state. This study experimentally characterizes laser surface hardening of tool steel in both water and air. For the underwater operation, laser surface scanning is performed over the tool steel surface which is immersed in water. The laser surface hardening tests are performed with a maximum 200 W fiber laser with a ...

  18. First Results of Continuous GPS Monitoring of Surface Deformation at the Aquistore Underground CO2 Storage Site

    Science.gov (United States)

    Craymer, M. R.; Ferland, R.; Piraszewski, M.; Samsonov, S. V.; Czarnogorska, M.

    2014-12-01

    Aquistore is a demonstration project for the underground storage of CO2 at a depth of ~3350 m near Estevan, Saskatchewan, Canada. An objective of the project is to design, adapt, and test non-seismic monitoring methods that have not been systematically utilized to date for monitoring CO2 storage projects, and to integrate the data from these various monitoring tools to obtain quantitative estimates of the change in subsurface fluid distributions, pressure changes and associated surface deformation. Monitoring methods being applied include satellite-, surface- and wellbore-based monitoring systems and comprise natural- and controlled-source electromagnetic methods, gravity monitoring, GPS, synthetic aperture radar interferometry (InSAR), tiltmeter array analysis, and chemical tracer studies. Here we focus on the GPS monitoring of surface deformation. Five GPS monitoring stations were installed in 2012 and another six in 2013, some collocated on top of InSAR retroreflectors. The GPS data from these stations have been processed on a weekly basis in both baseline processing mode using the Bernese GPS Software and precise point positioning mode using CSRS-PPP. Here we present the first complete results with 1-2 years of data at all sites prior to CO2 injection. The time series of these sites are examined, compared and analysed with respect to monument stability, seasonal signals and estimates of expected regional ground motion. The individual weekly network solutions have also been combined together in a cumulative 4D network solution to provide a preliminary local velocity field in the immediately vicinity of the injection well. These results are also compared to those obtained independently from InSAR, in particular the direct comparison of GPS and InSAR at the retroreflectors.

  19. Transcranial direct current stimulation in refractory continuous spikes and waves during slow sleep: a controlled study

    DEFF Research Database (Denmark)

    Varga, Edina T; Terney, Daniella; Atkins, Mary D;

    2011-01-01

    Cathodal transcranial direct current stimulation (tDCS) decreases cortical excitability. The purpose of the study was to investigate whether cathodal tDCS could interrupt the continuous epileptiform activity. Five patients with focal, refractory continuous spikes and waves during slow sleep were...... recruited. Cathodal tDCS and sham stimulation were applied to the epileptic focus, before sleep (1 mA; 20 min). Cathodal tDCS did not reduce the spike-index in any of the patients....

  20. Continuous deep sedation for patients nearing death in the Netherlands: descriptive study

    NARCIS (Netherlands)

    J.A.C. Rietjens (Judith); J.J.M. van Delden (Johannes); B.D. Onwuteaka-Philipsen (Bregje); H.M. Buiting (Hilde); P.J. van der Maas (Paul); A. van der Heide (Agnes)

    2008-01-01

    textabstractObjectives To study the practice of continuous deep sedation in 2005 in the Netherlands and compare it with findings from 2001. Design Questionnaire study about random samples of deaths reported to a central death registry in 2005 and 2001. Setting Nationwide physician study in the Net

  1. Continuous care and patients' basic needs during weaning from mechanical ventilation: A qualitative study.

    Science.gov (United States)

    Khalafi, Ali; Elahi, Nasrin; Ahmadi, Fazlollah

    2016-12-01

    Mechanical ventilation is associated with a number of risks and complications. Thus, rapid and safe weaning from mechanical ventilation is of great importance. Weaning is a complex and challenging process, requiring continuous care and knowledge of the patient. The aim of the present study was to describe the continuous care process during weaning as well as to analyse the facilitators and obstacles to the weaning process from start to finish from the perspective of intensive care unit (ICU) staff, particularly nurses. Twenty-two ICU staff members, including nurses and physicians, and three patients hospitalised in the ICU were enrolled in this qualitative study. Semi-structured interviews were used for data collection and the transcripts were analysed using qualitative content analysis. 'Continuous care' was found to be the patients' basic need during weaning from mechanical ventilation. Uninterrupted, stable, comprehensive and dynamic care and monitoring with immediate response to all physiological and psychological changes were features of continuous care. The three main themes identified by this study were time spent with the patient, comprehensive supervision and maintenance of the quality of care during shifts. Continuous and constant care should be provided during the weaning process. Such care will help to provide health care staff with a deeper understanding of the patient and his or her continuous changes, leading to a timely and favourable response during weaning. To achieve this goal, skill, communication and organisational changes are essential. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Oynophagia in patients after dental extraction: surface electromyography study.

    Science.gov (United States)

    Vaiman, Michael; Nahlieli, Oded; Eliav, Eli

    2006-10-17

    Surface electromyographic (sEMG) studies were performed on 40 adult patients following extraction of lower third and second molars to research the approach and limitations of sEMG evaluation of their odynophagia complaints. Parameters evaluated during swallowing and drinking include the timing, number of swallows per 100 cc of water, and range (amplitude) of EMG activity of m. masseter, infrahyoid and submental-submandibular group. The above mentioned variables (mean + standard deviation) were measured for the group of dental patients (n = 40) and control group of healthy adults (n = 40). The duration of swallows and drinking in all tests showed increase in dental patients' group, in which this tendency is statistically significant. There was no statistically significant difference between male and female adults' duration and amplitude of muscle activity during continuous drinking in both groups (p = 0.05). The mean of electric activity (in muV) of m. masseter was significantly lower in the dental patients' group in comparison with control group. The electric activity of submental-submandimular and infrahyoid muscle groups was the same in both groups. Surface EMG of swallowing is a simple and reliable noninvasive method for evaluation of odynophagia/dysphagia complaints following dental extraction with low level of discomfort of the examination. The surface EMG studies prove that dysphagia following dental extraction and molar surgery has oral origin, does not affect pharingeal segment and submental-submandibular muscle group. This type of dysphagia has clear EMG signs: increased duration of single swallow, longer drinking time, low range of electric activity of m. masseter, normal range of activity of submental-submandibular muscle group, and the "dry swalow" aftereffect. The data can be used for evaluation of complaints and symptoms, as well as for comparison purposes in pre- and postoperative stages and in EMG monitoring during treatment of post-surgical oral

  3. Oynophagia in patients after dental extraction: surface electromyography study

    Directory of Open Access Journals (Sweden)

    Nahlieli Oded

    2006-10-01

    Full Text Available Abstract Objectives Surface electromyographic (sEMG studies were performed on 40 adult patients following extraction of lower third and second molars to research the approach and limitations of sEMG evaluation of their odynophagia complaints. Methods Parameters evaluated during swallowing and drinking include the timing, number of swallows per 100 cc of water, and range (amplitude of EMG activity of m. masseter, infrahyoid and submental-submandibular group. The above mentioned variables (mean + standard deviation were measured for the group of dental patients (n = 40 and control group of healthy adults (n = 40. Results The duration of swallows and drinking in all tests showed increase in dental patients' group, in which this tendency is statistically significant. There was no statistically significant difference between male and female adults' duration and amplitude of muscle activity during continuous drinking in both groups (p = 0.05. The mean of electric activity (in μV of m. masseter was significantly lower in the dental patients' group in comparison with control group. The electric activity of submental-submandimular and infrahyoid muscle groups was the same in both groups. Conclusion Surface EMG of swallowing is a simple and reliable noninvasive method for evaluation of odynophagia/dysphagia complaints following dental extraction with low level of discomfort of the examination. The surface EMG studies prove that dysphagia following dental extraction and molar surgery has oral origin, does not affect pharingeal segment and submental-submandibular muscle group. This type of dysphagia has clear EMG signs: increased duration of single swallow, longer drinking time, low range of electric activity of m. masseter, normal range of activity of submental-submandibular muscle group, and the "dry swalow" aftereffect. The data can be used for evaluation of complaints and symptoms, as well as for comparison purposes in pre- and postoperative stages and

  4. Accumulated versus continuous exercise for health benefit: a review of empirical studies.

    Science.gov (United States)

    Murphy, Marie H; Blair, Steven N; Murtagh, Elaine M

    2009-01-01

    Current physical activity guidelines endorse the notion that the recommended amount of daily physical activity can be accumulated in short bouts performed over the course of a day. Although intuitively appealing, the evidence for the efficacy of accumulated exercise is not plentiful. The purpose of this review was to compare the effects of similar amounts of exercise performed in either one continuous or two or more accumulated bouts on a range of health outcomes. Sixteen studies met the selection criteria for inclusion in the review, in which at least one outcome known to affect health was measured before and after continuous and accumulated exercise training interventions. Where improvements in cardiovascular fitness were noted, most studies reported no difference in the alterations between accumulated and continuous patterns of exercise. In the few studies where a normalization of blood pressure was observed from baseline to post-intervention, there appear to be no differences between accumulated and continuous exercise in the magnitude of this effect. For other health outcomes such as adiposity, blood lipids and psychological well-being, there is insufficient evidence to determine whether accumulated exercise is as effective as the more traditional continuous approach. Seven short-term studies in which at least one health-related outcome was measured during the 0- to 48-hour period after a single continuous bout of exercise and a number of short bouts of equivalent total duration were included in the review. Many of the studies of such short-term effects considered the plasma triglyceride response to a meal following either accumulated short or continuous bouts of exercise. Collectively, these studies suggest that accumulated exercise may be as effective at reducing postprandial lipaemia. Further research is required to determine if even shorter bouts of accumulated exercise (benefit and whether an accumulated approach to physical activity increases adherence

  5. Continuous Flow Liquid Microjunction Surface Sampling Probe Connected On-line with HPLC/MS for Spatially Resolved Analysis of Small Molecules and Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Van Berkel, Gary J [ORNL; Kertesz, Vilmos [ORNL

    2013-01-01

    RATIONALE: A continuous flow liquid microjunction surface sampling probe extracts soluble material from surfaces for direct ionization and detection by MS. Demonstrated here is the on-line coupling of such a probe with HPLC/MS enabling extraction, separation and detection of small molecules and proteins from surfaces in a spatially resolved (~0.5 mm diameter spots) manner. Methods: A continuous flow liquid microjunction surface sampling probe was connected to a 6-port, 2-position valve for extract collection and injection to an HPLC column. A QTRAP 5500 hybrid triple quadrupole linear ion trap equipped with a Turbo V ion source operated in positive ESI mode was used for all experiments. System operation was tested with extraction, separation and detection of propranolol and associated metabolites from drug dosed tissues and proteins from dried sheep blood spots on paper. Results: Confirmed in the tissue were the parent drug and two different hydroxypropranolol glucuronides. The mass spectrometric response for these compounds from different locations in the liver showed an increase with increasing extraction time (5, 20 and 40 s extractions). For on-line separation and detection/identification of extracted proteins from dried sheep blood spots, two major protein peaks dominated the chromatogram and could be correlated with the expected masses for the hemoglobin and chains. Conclusions: Spatially resolved sampling, separation, and detection of small molecules and proteins from surfaces can be accomplished using a continuous flow liquid microjunction surface sampling probe coupled on-line with HPLC/MS detection.

  6. Study the Postbuckling of Hexagonal Piezoelectric Nanowires with Surface Effect

    Directory of Open Access Journals (Sweden)

    O. Rahmani

    2014-04-01

    Full Text Available Piezoelectric nanobeams having circular, rectangular and hexagonal cross-sections are synthesized and used in various Nano structures; however, piezoelectric nanobeams with hexagonal cross-sections have not been studied in detail. In particular, the physical mechanisms of the surface effect and the role of surface stress, surface elasticity and surface piezoelectricity have not been discussed thoroughly. The present study investigated post-buckling behavior of piezoelectric nanobeams by examining surface effects. The energy method was applied to post-buckling of hexagonal nanobeams and the critical buckling voltage and amplitude are derived analytically from bulk and surface material properties and geometric factors.

  7. Characterization of the banana streak virus capsid protein and mapping of the immunodominant continuous B-cell epitopes to the surface-exposed N terminus.

    Science.gov (United States)

    Vo, Jenny N; Campbell, Paul R; Mahfuz, Nur N; Ramli, Ras; Pagendam, Daniel; Barnard, Ross; Geering, Andrew D W

    2016-12-01

    This study identified the structural proteins of two badnavirus species, Banana streak MY virus (BSMYV) and Banana streak OL virus (BSOLV), and mapped the distribution of continuous B-cell epitopes. Two different capsid protein (CP) isoforms of about 44 and 40 kDa (CP1 and CP2) and the virion-associated protein (VAP) were consistently associated with purified virions. For both viral species, the N terminus of CP2 was successfully sequenced by Edman degradation but that of CP1 was chemically blocked. De novo peptide sequencing of tryptic digests suggested that CP1 and CP2 derive from the same region of the P3 polyprotein but differ in the length of either the N or the C terminus. A three-dimensional model of the BSMYV-CP was constructed, which showed that the CP is a multi-domain structure, containing homologues of the retroviral capsid and nucleocapsid proteins, as well as a third, intrinsically disordered protein region at the N terminus, henceforth called the NID domain. Using the Pepscan approach, the immunodominant continuous epitopes were mapped to the NID domain for five different species of banana streak virus. Anti-peptide antibodies raised against these epitopes in BSMYV were successfully used for detection of native virions and denatured CPs in serological assays. Immunoelectron microscopy analysis of the virion surface using the anti-peptide antibodies confirmed that the NID domain is exposed on the surface of virions, and that the difference in mass of the two CP isoforms is due to variation in length of the NID domain.

  8. Surface Plasmon Resonance Studies on Molecular Imprinting

    Directory of Open Access Journals (Sweden)

    Baoping Lin

    2002-01-01

    Full Text Available The molecular imprinted polymer (MIP members were fabricated with the print molecule L-phenylalanine ethyl ester. The elution and adsorption procedures were investigated by surface plasmon resonance in situ. The changes of refractive angle during elution procedure suggest that the MIP is prepared on the base of the non-covalent interactions. This MIP member sensor can achieve enantioselective recognition.

  9. Target studies for surface muon production

    Science.gov (United States)

    Berg, F.; Desorgher, L.; Fuchs, A.; Hajdas, W.; Hodge, Z.; Kettle, P.-R.; Knecht, A.; Lüscher, R.; Papa, A.; Rutar, G.; Wohlmuther, M.

    2016-02-01

    Meson factories are powerful drivers of diverse physics programs. With beam powers already in the MW-regime attention has to be turned to target and beam line design to further significantly increase surface muon rates available for experiments. For this reason we have explored the possibility of using a neutron spallation target as a source of surface muons by performing detailed Geant4 simulations with pion production cross sections based on a parametrization of existing data. While the spallation target outperforms standard targets in the backward direction by more than a factor 7 it is not more efficient than standard targets viewed under 90°. Not surprisingly, the geometry of the target plays a large role in the generation of surface muons. Through careful optimization, a gain in surface muon rate of between 30% and 60% over the standard "box-like" target used at the Paul Scherrer Institute could be achieved by employing a rotated slab target. An additional 10% gain could also be possible by utilizing novel target materials such as, e.g., boron carbide.

  10. Target Studies for Surface Muon Production

    CERN Document Server

    Berg, F; Fuchs, A; Hajdas, W; Hodge, Z; Kettle, P -R; Knecht, A; Lüscher, R; Papa, A; Rutar, G; Wohlmuther, M

    2015-01-01

    Meson factories are powerful drivers of diverse physics programmes. With beam powers already in the MW-regime attention has to be turned to target and beam line design to further significantly increase surface muon rates available for experiments. For this reason we have explored the possibility of using a neutron spallation target as a source of surface muons by performing detailed Geant4 simulations with pion production cross sections based on a parametrization of existing data. While the spallation target outperforms standard targets in the backward direction by more than a factor 7 it is not more efficient than standard targets viewed under 90{\\deg}. Not surprisingly, the geometry of the target plays a large role in the generation of surface muons. Through careful optimization, a gain in surface muon rate of between 30 - 60% over the standard "box-like" target used at the Paul Scherrer Institute could be achieved by employing a rotated slab target. An additional 10% gain could also be possible by utilizin...

  11. Kinetic Study of Acetone-Butanol-Ethanol Fermentation in Continuous Culture.

    Science.gov (United States)

    Buehler, Edward A; Mesbah, Ali

    2016-01-01

    Acetone-butanol-ethanol (ABE) fermentation by clostridia has shown promise for industrial-scale production of biobutanol. However, the continuous ABE fermentation suffers from low product yield, titer, and productivity. Systems analysis of the continuous ABE fermentation will offer insights into its metabolic pathway as well as into optimal fermentation design and operation. For the ABE fermentation in continuous Clostridium acetobutylicum culture, this paper presents a kinetic model that includes the effects of key metabolic intermediates and enzymes as well as culture pH, product inhibition, and glucose inhibition. The kinetic model is used for elucidating the behavior of the ABE fermentation under the conditions that are most relevant to continuous cultures. To this end, dynamic sensitivity analysis is performed to systematically investigate the effects of culture conditions, reaction kinetics, and enzymes on the dynamics of the ABE production pathway. The analysis provides guidance for future metabolic engineering and fermentation optimization studies.

  12. Kinetic Study of Acetone-Butanol-Ethanol Fermentation in Continuous Culture

    Science.gov (United States)

    Buehler, Edward A.; Mesbah, Ali

    2016-01-01

    Acetone-butanol-ethanol (ABE) fermentation by clostridia has shown promise for industrial-scale production of biobutanol. However, the continuous ABE fermentation suffers from low product yield, titer, and productivity. Systems analysis of the continuous ABE fermentation will offer insights into its metabolic pathway as well as into optimal fermentation design and operation. For the ABE fermentation in continuous Clostridium acetobutylicum culture, this paper presents a kinetic model that includes the effects of key metabolic intermediates and enzymes as well as culture pH, product inhibition, and glucose inhibition. The kinetic model is used for elucidating the behavior of the ABE fermentation under the conditions that are most relevant to continuous cultures. To this end, dynamic sensitivity analysis is performed to systematically investigate the effects of culture conditions, reaction kinetics, and enzymes on the dynamics of the ABE production pathway. The analysis provides guidance for future metabolic engineering and fermentation optimization studies. PMID:27486663

  13. Study on the relationship of continuous laser printing and the distance of trace on the OPC

    Directory of Open Access Journals (Sweden)

    Xingzhou Han

    2017-01-01

    Full Text Available This thesis aims to seek the relationship between photosensitive drum cyclical trace distance of two pages (shorted for L' and continuity printing of laser printers. Characteristics quantification, statistics are chosen to evaluate the data and results. It is indicated that the regularity is existed between L' and continuity printing, and regular performance between different models of HP and Canon printers are consistent. According to the data, L' of continuous printing are summed up, the probability of replacing the front page and the middle page which can meet the continuity regularity are analyzed. The numerical interval is given of noncontinuous printing. The study can enhance the scientificity of printing document examination and have innovation and practical significance in civil disputes, criminal cases, and social community.

  14. Synchrotron x-ray diffraction study of liquid surfaces

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Pershan, P.S.

    1983-01-01

    A spectrometer for X-ray diffraction and refraction studies of horizontal, free surfaces of liquids is described. As an illustration smetic-A layering at the surface of a liquid crystal is presented.......A spectrometer for X-ray diffraction and refraction studies of horizontal, free surfaces of liquids is described. As an illustration smetic-A layering at the surface of a liquid crystal is presented....

  15. Synchrotron x-ray diffraction study of liquid surfaces

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Pershan, P.S.

    1983-01-01

    A spectrometer for X-ray diffraction and refraction studies of horizontal, free surfaces of liquids is described. As an illustration smetic-A layering at the surface of a liquid crystal is presented.......A spectrometer for X-ray diffraction and refraction studies of horizontal, free surfaces of liquids is described. As an illustration smetic-A layering at the surface of a liquid crystal is presented....

  16. In situ high temperature microscopy study of the surface oxidation and phase transformations in titanium alloys.

    Science.gov (United States)

    Malinov, S; Sha, W; Voon, C S

    2002-09-01

    Two popular commercial titanium alloys, Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo-0.08Si, were used for in situ high temperature microscopy study. The experiments were performed on an optical microscope equipped with high temperature stage using both normal and florescence lights. Two kinds of experiments were performed, at continuous heating/cooling with different rates and in isothermal conditions at different temperatures. The changes taking place on the sample surface during the experiments were monitored. The morphology of the alpha ==> beta ==> alpha phase transformation was recorded at different heat treatment conditions using the effect of thermal etching. An effect of sample surface oxidation and deoxidation was observed during continuous heating. The appearance and disappearance of ordered titanium oxides Ti3O and Ti2O are discussed based on the phase equilibrium diagram. The kinetics of the surface oxidation was monitored in both isothermal and continuous cooling conditions.

  17. Study of Surface Cell Madelung Constant and Surface Free Energy of Nanosized Crystal Grain

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-Jia; WANG Tian-Min; CUI Min

    2005-01-01

    Surface cell Madelung constant is firstly defined in calculating surface free energy of nanosized crystal grains, which explains the physical performance of small crystals and may be great benefit to make surface analysis and study dynamics of crystal nucleus growth. A new ap- proximative expression of surface energy and relevant thermodynamic data was used in this cal- culation. A new formula and computing method for calculating the Madelung constant α of any complex crystals is proposed, and surface free energies and surface electrostatic energies of nano- sized crystal grains as well as Madelung constant of some complex crystals are theoretically cal- culated in this paper. The surface free energy of nanosized crystal grain TiO2 and surface elec- trostatic energy(absolute value) of nanosized crystal grain α-Al2O3 are found to be the biggest among other crystal grains.

  18. Study of surface cell Madelung constant and surface free energy of nanosized crystal grain

    Institute of Scientific and Technical Information of China (English)

    Zhang Wei-Jia; Wang Tian-Min; Rong Ai-Lun; Cui Min

    2006-01-01

    Surface cell Madelung constant is firstly defined for calculating the surface free energy of nanosized crystal grains,which explains the physical performance of small crystals and may be greatly beneficial to the analysis of surface states and the study of the dynamics of crystal nucleation and growth.A new approximative expression of the surface energy and relevant thermodynamic data are used in this calculation.New formula and computing method for calculating the Madelung constant α of any complex crystals are proposed,and the surface free energies and surface electrostatic energies of nanosized crystal grains and the Madelung constant of some complex crystals are theoretically calculated in this paper.The surface free energy of nanosized-crystal-grain TiO2 and the surface electrostatic energy (absolute value) of nanosized-crystal-grain α-A12O3 are found to be the biggest among all the crystal grains including those of other species.

  19. Effects of Continued Care: A Study of Chronic Illness in the Home.

    Science.gov (United States)

    Katz, Sidney; And Others

    This study of chronic illness in the home originates in theoretical and practical questions posed by physicians, nurses, and biometricians. The study covers the following elements: The research plan, the patient sample, providing continued care, interviewing, classification of disease and mental status, effect of treatment program, classification…

  20. A Descriptive Study of Intrinsic Motivation in Three California Accredited Model Continuation High Schools

    Science.gov (United States)

    Dike, Daniel E.

    2012-01-01

    Purpose: The first purpose of this study was to identify and describe teachers' perceptions of intrinsic motivation in classrooms among at-risk adolescent students in 3 model continuation high schools. The second purpose of this study was to identify and describe teacher practices that promote intrinsic motivation among at-risk adolescent students…

  1. The Role of Cultural Context in Continuing Vocational Training: A Study on Auto Repairmen in Turkey

    Science.gov (United States)

    Akbas, Oktay

    2011-01-01

    This study analysed how auto repairmen working in micro-enterprises undertake continuing vocational training in relation to cultural context. The study was conducted in Kirikkale, a city in central Anatolia in Turkey. To this end, the descriptive research technique of structured interview was used. Interviews with 33 auto repairmen were recorded…

  2. Surface studies of magnetic thin films

    CERN Document Server

    Zeybek, O

    2000-01-01

    Despite the resonances of the various multiplet components the dichroism signal retains a uniform spectral shape. The well-resolved multiplet structures have been obtained in 5p photoemission of Tb using circularly polarised light. This multiplet structure is caused by the interaction between the core level photohole and those partially filled subshell, i.e. as result of the unpaired 4f and 5p electrons. In 4f levels of Tb(0001) films, the well-resolved surface component of the Tb sup 8 S sub 7 sub / sub 2 has been observed a separation of magnetic circular dichroism in the angular dependence effect for the surface layer and for the bulk. Depending on the preparation procedure, new iron superstructures on W(110) substrate have been observed. The photographs of the LEED images provide information about the ordered arrangement of atoms on the surface and the distances between the spots. These LEED patterns are also an evidence of crystal structure of iron films. The sharpness of the spots gives insight on how w...

  3. Continuation of copper and levonorgestrel intrauterine devices: a retrospective cohort study.

    Science.gov (United States)

    Phillips, Sharon J; Hofler, Lisa G; Modest, Anna M; Harvey, Lara F B; Wu, Lily H; Hacker, Michele R

    2017-07-01

    Studies conflict on whether the duration of use of the copper intrauterine device is longer than that of the levonorgestrel intrauterine device, and whether women who continue using intrauterine devices differ from those who discontinue. We sought to assess continuation rates and performance of levonorgestrel intrauterine devices compared with copper intrauterine devices over a 5-year period. We performed a retrospective cohort study of 1164 individuals who underwent intrauterine device placement at an urban academic medical center. The analysis focused on a comparison of continuation rates between those using levonorgestrel intrauterine device and copper intrauterine device, factors associated with discontinuation, and intrauterine device performance. We assessed the differences in continuation at discrete time points, pregnancy, and expulsion rates using χ(2) tests and calculated hazard ratios using a multivariable Cox model. Of 1164 women who underwent contraceptive intrauterine device insertion, 956 had follow-up data available. At 2 years, 64.9% of levonorgestrel intrauterine device users continued their device, compared with 57.7% of copper intrauterine device users (P = .11). At 4 years, continuation rates were 45.1% for levonorgestrel intrauterine device and 32.6% for copper intrauterine device (P 4 years was 0.71 (95% confidence interval, 0.55-0.93) and >5 years was 0.82 (95% confidence interval, 0.64-1.05) after adjusting for race, age, parity, and education. Copper intrauterine device users were more likely to experience expulsion (10.2% copper intrauterine device vs 4.9% levonorgestrel intrauterine device, P < .01) over the study period and to become pregnant in the first year of use (1.6% copper intrauterine device vs 0.1% levonorgestrel intrauterine device, P < .01). We found a difference in continuation rates between levonorgestrel and copper intrauterine device users at 4 years but not at 5 years. Copper intrauterine device users were more likely

  4. Abdominal wound closure. A randomized prospective study of 571 patients comparing continuous vs. interrupted suture techniques.

    Science.gov (United States)

    Richards, P C; Balch, C M; Aldrete, J S

    1983-01-01

    A randomized, prospective study was designed to compare a continuous with an interrupted technique for closing an abdominal incision. Five hundred seventy-one patients were randomized between the closure methods and stratified as to type of wound: clean, clean-contaminated, or contaminated. In mid-line incisions, the dehiscence rate was 2.0% (5/244) for the continuous group versus 0.9% (2/229) for the interrupted group. The difference was not statistically significant. Ventral hernias formed in 2.0% (4/201) of the continuous group vs. 0.5% (1/184) of the interrupted group. The type of wound had no influence on the results. In oblique incisions, 0% (0/39) of wounds closed continuously dehised while 2% (1/50) of incisions closed interruptedly dehised. No ventral hernias formed. Further analysis of the data indicated that dehiscence was more likely related to improper surgical technique than to the method of closure. An abdominal incision could be closed with a continuous suture in approximately half the time required for placing interrupted sutures (20 vs. 40 minutes). A continuous closure is preferred because it is more expedient and because it has the same incidence of wound disruption compared with an interrupted closure. PMID:6297417

  5. Experimental study on effect of surface vibration on micro textured surfaces with hydrophobic and hydrophilic materials

    Science.gov (United States)

    Yao, Chun-Wei; Lai, Chen-Ling; Alvarado, Jorge L.; Zhou, Jiang; Aung, Kendrick T.; Mejia, Jose E.

    2017-08-01

    Artificial hydrophobic surfaces have been studied in the last ten years in an effort to understand the effects of structured micro- and nano-scale features on droplet motion and self-cleaning mechanisms. Among these structured surfaces, micro-textured surfaces consisting of a combination of hydrophilic and hydrophobic materials have been designed, fabricated and characterized to understand how surface properties and morphology affect enhanced self-cleaning mechanisms. However, use of micro textured surfaces leads to a strong pinning effect that takes place between the droplets and the hydrophobic-hydrophilic edge, leading to a significant contact angle hysteresis effect. This research study focuses on the effects of surface vibrations on droplet shedding at different inclined angles on micro-textured surfaces. Surface vibration and shedding processes were experimentally characterized using a high speed imaging system. Experimental results show that droplets under the influence of surface vibration depict different contour morphologies when vibrating at different resonance frequencies. Moreover, droplet sliding angles can be reduced through surface vibration when the proper combination of droplet size and surface morphology is prescribed.

  6. Stability of Surface Nanobubbles: A Molecular Dynamics Study

    NARCIS (Netherlands)

    Maheshwari, Shantanu; Hoef, van der Martin; Zhang, Xuehua; Lohse, Detlef

    2016-01-01

    The stability and growth or dissolution of a single surface nanobubble on a chemically patterned surface are studied by molecular dynamics simulations of binary mixtures consisting of Lennard-Jones (LJ) particles. Our simulations reveal how pinning of the three-phase contact line on the surface can

  7. Theoretical studies of potential energy surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Harding, L.B. [Argonne National Laboratory, IL (United States)

    1993-12-01

    The goal of this program is to calculate accurate potential energy surfaces (PES) for both reactive and nonreactive systems. To do this the electronic Schrodinger equation must be solved. Our approach to this problem starts with multiconfiguration self-consistent field (MCSCF) reference wavefunctions. These reference wavefunctions are designed to be sufficiently flexible to accurately describe changes in electronic structure over a broad range of geometries. Electron correlation effects are included via multireference, singles and doubles configuration interaction (MRSDCI) calculations. With this approach, the authors are able to provide useful predictions of the energetics for a broad range of systems.

  8. Experimental studies of liquid marbles and superhydrophobic surfaces

    OpenAIRE

    Elliott, SJ

    2009-01-01

    The interaction of water droplets with hydrophobic or rough, superhydrophobic solid surfaces has been studied. Such surfaces may be found in the natural world and their potential applications range from waterproof and self-cleaning surfaces to droplet microfluidics. A measure of hydrophobicity is obtained from the angle between the liquid and solid surface measured from the solid through the liquid, known as the contact angle. Variations in this angle can indicate not only a level of ‘wetting...

  9. Ab initio study of proton dynamics on perovskite oxide surfaces

    Directory of Open Access Journals (Sweden)

    Fuyuki Shimojo

    2007-01-01

    Full Text Available First-principles studies of the proton dynamics in perovskite oxides and the water adsorption on various oxide surfaces are briefly reviewed. Recent progress in the study of the microscopic mechanism of the proton absorption from perovskite oxide surfaces is also presented. It is shown that dopant ions on the surface and oxygen vacancies in the inside just below the surface play an important role for the proton absorption, while oxygen vacancies on the surface are influential for the dissociative adsorption of water molecules.

  10. A study on the fabrication of main scale of linear encoder using continuous roller imprint method

    Science.gov (United States)

    Fan, Shanjin; Shi, Yongsheng; Yin, Lei; Feng, Long; Liu, Hongzhong

    2013-10-01

    Linear encoder composed of main and index scales has an extensive application in the field of modern precision measurement. The main scale is the key component of linear encoder as measuring basis. In this article, the continuous roller imprint technology is applied to the manufacturing of the main scale, this method can realize the high efficiency and low cost manufacturing of the ultra-long main scale. By means of the plastic deformation of the soft metal film substrate, the grating microstructure on the surface of the cylinder mold is replicated to the soft metal film substrate directly. Through the high precision control of continuous rotational motion of the mold, ultra-long high precision grating microstructure is obtained. This paper mainly discusses the manufacturing process of the high precision cylinder mold and the effects of the roller imprint pressure and roller rotation speed on the imprint replication quality. The above process parameters were optimized to manufacture the high quality main scale. At last, the reading test of a linear encoder contains the main scale made by the above method was conducted to evaluate its measurement accuracy, the result demonstrated the feasibility of the continuous roller imprint method.

  11. Evaluation of the bioremoval of Cr(VI) and TOC in biofilters under continuous operation using response surface methodology.

    Science.gov (United States)

    Leles, Daniela M A; Lemos, Diego A; Filho, Ubirajara C; Romanielo, Lucienne L; de Resende, Miriam M; Cardoso, Vicelma L

    2012-06-01

    In the present study, the bioremoval of Cr(VI) and the removal of total organic carbon (TOC) were achieved with a system composed by an anaerobic filter and a submerged biofilter with intermittent aeration using a mixed culture of microorganisms originating from contaminated sludge. In the aforementioned biofilters, the concentrations of chromium, carbon, and nitrogen were optimized according to response surface methodology. The initial concentration of Cr(VI) was 137.35 mg l(-1), and a bioremoval of 85.23% was attained. The optimal conditions for the removal of TOC were 4 to 8 g l(-1) of sodium acetate, >0.8 g l(-1) of ammonium chloride and 60 to 100 mg l(-1) of Cr(VI). The results revealed that ammonium chloride had the strongest effect on the TOC removal, and 120 mg l(-1) of Cr(VI) could be removed after 156 h of operation. Moreover, 100% of the Cr(VI) and the total chromium content of the aerobic reactor output were removed, and TOC removals of 80 and 87% were attained after operating the anaerobic and aerobic reactors for 130 and 142 h, respectively. The concentrations of cells in both reactors remained nearly constant over time. The residence time distribution was obtained to evaluate the flow through the bioreactors.

  12. Postoperative analgesia with continuous epidural sufentanil and bupivacaine : A prospective study in 614 patients

    NARCIS (Netherlands)

    Broekema, AA; Gielen, MJM; Hennis, PJ

    1996-01-01

    To assess the efficacy and safety of postoperative analgesia with continuous epidural sufentanil and bupivacaine, we performed a prospective study in 614 patients undergoing major surgery. Before surgical incision, all patients received an initial dose of 50 mu g sufentanil in 6-10 mL bupivacaine 0.

  13. Word segmentation from continuous speech: An ERP study with 10-month-old infants

    NARCIS (Netherlands)

    Kooijman, V.M.; Hagoort, P.; Cutler, A.

    2004-01-01

    Behavioral studies have shown that infants can segment some words from continuous speech well before they begin to speak - from about 7.5 months of age for English-learning infants and from at least 9 months of age for Dutch-learning infants. The predominant stress pattern of these languages seems t

  14. Postoperative analgesia with continuous epidural sufentanil and bupivacaine : A prospective study in 614 patients

    NARCIS (Netherlands)

    Broekema, AA; Gielen, MJM; Hennis, PJ

    To assess the efficacy and safety of postoperative analgesia with continuous epidural sufentanil and bupivacaine, we performed a prospective study in 614 patients undergoing major surgery. Before surgical incision, all patients received an initial dose of 50 mu g sufentanil in 6-10 mL bupivacaine

  15. Study on 660-nm quasi-continuous-wave intracavity frequency-doubled Nd:YAG laser

    Institute of Scientific and Technical Information of China (English)

    Tao Wang(王涛); Jianquan Yao(姚建铨); Baigang Zhang(张百钢); Guiyan Zang(臧贵艳); Peng Wang(王鹏); Yizhong Yu(于意仲)

    2003-01-01

    A quasi-continuous-wave intracavity frequency-doubled Nd:YAG laser which operates at 660 nm is studied.By using a flat-flat laser cavity, 2 Kr-lamps, KTP crystal and an acousto-optically Q-switch, 2-W outputpower at 660 nm is obtained. The relationship between laser cavity length and output power is analyzed.

  16. Word segmentation from continuous speech: An ERP study with 10-month-old infants

    NARCIS (Netherlands)

    Kooijman, V.M.; Hagoort, P.; Cutler, A.

    2004-01-01

    Behavioral studies have shown that infants can segment some words from continuous speech well before they begin to speak - from about 7.5 months of age for English-learning infants and from at least 9 months of age for Dutch-learning infants. The predominant stress pattern of these languages seems

  17. General practitioners' continuing medical education: A prospective study from the County of Aarhus

    DEFF Research Database (Denmark)

    Nielsen, Jan E.; Lous, Jørgen; Adeler, H.F.;

    2002-01-01

    Participation of Danish general practitioners (GPs) in continuing medical education (CME) has often been the subject of debate, although very little is known about the extent and content of activities. One-hundred-and-sixty-one Danish GPs participated in this one-year prospective study...

  18. Assessing the operational life of flexible printed boards intended for continuous flexing applications : a case study.

    Energy Technology Data Exchange (ETDEWEB)

    Beck, David Franklin

    2011-01-01

    Through the vehicle of a case study, this paper describes in detail how the guidance found in the suite of IPC (Association Connecting Electronics Industries) publications can be applied to develop a high level of design assurance that flexible printed boards intended for continuous flexing applications will satisfy specified lifetime requirements.

  19. Effect of Continuous Assessment on Learning Outcomes on Two Chemical Engineering Courses: Case Study

    Science.gov (United States)

    Tuunila, R.; Pulkkinen, M.

    2015-01-01

    In this paper, the effect of continuous assessment on the learning outcomes of two chemical engineering courses is studied over a several-year period. Average grades and passing percentages of courses after the final examination are reported and also student feedback on the courses is collected. The results indicate significantly better learning…

  20. Design study of a continuously variable roller cone traction CVT for electric vehicles

    Science.gov (United States)

    Mccoin, D. K.; Walker, R. D.

    1980-01-01

    Continuously variable ratio transmissions (CVT) featuring cone and roller traction elements and computerized controls are studied. The CVT meets or exceeds all requirements set forth in the design criteria. Further, a scalability analysis indicates the basic concept is applicable to lower and higher power units, with upward scaling for increased power being more readily accomplished.

  1. A comparative study of biomolecule and polymer surface modifications by a surface microdischarge

    Science.gov (United States)

    Bartis, Elliot A. J.; Luan, Pingshan; Knoll, Andrew J.; Graves, David B.; Seog, Joonil; Oehrlein, Gottlieb S.

    2016-02-01

    Cold atmospheric plasma (CAP) sources are attractive sources of reactive species with promising industrial and biomedical applications, but an understanding of underlying surface mechanisms is lacking. A kHz-powered surface microdischarge (SMD) operating with N2/O2 mixtures was used to study the biological deactivation of two immune-stimulating biomolecules: lipopolysaccharide (LPS) and peptidoglycan (PGN), found in bacteria such as Escherichia coli and Staphylococcus aureus, respectively. Model polymers were also studied to isolate specific functional groups. Changes in the surface chemistry were measured to understand which plasma-generated species and surface modifications are important for biological deactivation. The overall goal of this work is to determine which effects of CAP treatment are generic and which bonds are susceptible to attack. CAP treatment deactivated biomolecules, oxidized surfaces, and introduced surface bound NO3. These effects can be controlled by the N2 fraction in O2 and applied voltage and vary among different target surfaces. The SMD was compared with an Ar/O2/N2-fed kHz-powered atmospheric pressure plasma jet and showed much higher surface modifications and surface chemistry tunability compared to the jet. Possible mechanisms are discussed and findings are compared with recent computational investigations. Our results demonstrate the importance of long-lived plasma-generated species and advance an atomistic understanding of CAP-surface interactions.

  2. Formation of continuous metallic film on quartz studied by noncontact resonant ultrasound spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, N., E-mail: nobutomo@me.es.osaka-u.ac.jp; Yoshimura, N.; Ogi, H.; Hirao, M. [Osaka University, Graduate School of Engineering Science, Toyonaka, Osaka 560-8531 (Japan)

    2015-08-28

    Dynamics of continuous film formation of metallic films on quartz substrates is studied using an electrodeless resonance method. Bare quartz is used as a substrate, and a metallic film is deposited on it. We use antenna transmission technique to measure the evolution of resonance frequencies and internal friction of the substrate during and after deposition, and the morphological transition between discontinuous islands and a continuous film is detected. By comparison with atomic force microscopy images, we confirm that the frequency drop and the internal-friction peak that appear during deposition indicate this transition. We also find that Pt film shows unexpected morphology change after deposition.

  3. Feasibility Studies on Underwater Laser Surface Hardening Process

    Directory of Open Access Journals (Sweden)

    Biao Jin

    2015-01-01

    Full Text Available Laser surface hardening process is a very promising hardening method for ferrous and nonferrous alloys where transformations occur during cooling after laser melting in the solid state. This study experimentally characterizes laser surface hardening of tool steel in both water and air. For the underwater operation, laser surface scanning is performed over the tool steel surface which is immersed in water. The laser surface hardening tests are performed with a maximum 200 W fiber laser with a Gaussian distribution of energy in the beam. For the surface hardening, single-track melting experiment which sequentially scans elongated path of single line has been performed. As the hardened depth depends on the thermal conductivity of the material, the surface temperature and the penetration depth may be varied by underwater laser processing. The feasibility of underwater laser surface hardening process is discussed on the basis of average hardness level and hardened bead shape.

  4. Continuous Integration and Quality Assurance: a case study of two open source projects

    Directory of Open Access Journals (Sweden)

    Jesper Holck

    2003-11-01

    Full Text Available A decentralized variant of continuous integration can be defined in terms of two fundamental rules: (1 Developers’ access to add contributions to the development version at any time, and (2 developers’ obligation to integrate their own contributions properly. Decentralized, continuous integration may adapt well to organizations where developers work relatively independently, as in many open source projects. The approach raises the issue of how these organizations can exercise central control, as attaining the benefits of continuous integration requires that contributions are useful and satisfy the project’s definition of successful integration. We have investigated the use of continuous integration in FreeBSD and Mozilla. Our account of quality assurance activities in the two open source projects distinguishes between Mintzberg’s three complementary forms of central control: Standardization and control of work output, work processes, and worker skills. Our study indicates that two major challenges face projects using decentralized, continuous integration: (1 To balance the access to add contributions against the need to stabilize and mature the software prior to a release, and (2 to consider the developers’ limited time and resources when interpreting their obligation to integrate their changes properly.

  5. Exploratory Study for Continuous-time Parameter Estimation of Ankle Dynamics

    Science.gov (United States)

    Kukreja, Sunil L.; Boyle, Richard D.

    2014-01-01

    Recently, a parallel pathway model to describe ankle dynamics was proposed. This model provides a relationship between ankle angle and net ankle torque as the sum of a linear and nonlinear contribution. A technique to identify parameters of this model in discrete-time has been developed. However, these parameters are a nonlinear combination of the continuous-time physiology, making insight into the underlying physiology impossible. The stable and accurate estimation of continuous-time parameters is critical for accurate disease modeling, clinical diagnosis, robotic control strategies, development of optimal exercise protocols for longterm space exploration, sports medicine, etc. This paper explores the development of a system identification technique to estimate the continuous-time parameters of ankle dynamics. The effectiveness of this approach is assessed via simulation of a continuous-time model of ankle dynamics with typical parameters found in clinical studies. The results show that although this technique improves estimates, it does not provide robust estimates of continuous-time parameters of ankle dynamics. Due to this we conclude that alternative modeling strategies and more advanced estimation techniques be considered for future work.

  6. An experimental study on thermo-catalytic pyrolysis of plastic waste using a continuous pyrolyser.

    Science.gov (United States)

    Auxilio, Anthony R; Choo, Wei-Lit; Kohli, Isha; Chakravartula Srivatsa, Srikanth; Bhattacharya, Sankar

    2017-09-01

    A bench scale, two-stage, thermo-catalytic reactor equipped with a continuous feeding system was used to pyrolyse pure and waste plastics. Experiments using five zeolitic and clay-based catalysts of different forms (pellet and powders) and different plastic feedstocks - virgin HDPE, HDPE w1aste and mixed plastic waste (MPW) were compared to the control experiments - pyrolysis without catalyst. Results indicated that the two pelletized catalysts were the most promising for the conditions employed. Of these two, one with higher acidity and surface area was highly selective for the gasoline fraction (C5-C11) giving 80% from the total medium distillate conversion using virgin HDPE as feedstock. It also produced the least amount of olefins (17% for virgin HDPE, 4% for HDPE waste and 2% for MPW) and coke (pelletized catalyst exhibited high selectivity for the diesel fraction (C12-C25) giving 63% from the total medium distillate conversion using virgin HDPE as feedstock. The amount of coke deposited on the catalyst surface depended mainly on the mesopore volume, with less coke deposited as the mesopore volume increased. The variation in catalyst selectivity with acidity strength due to Lewis sites on the catalyst surface controls selectivity towards carbon chain length. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Thin films of solid electrolytes and studies of their surface

    Science.gov (United States)

    Pan, Xiaoren; Gu, Zhi X.

    1991-11-01

    Much research work has been done on the materials of solid electrolytes and their applications. Solid electrolytes or fast ionic conductors are generally used in solid state batteries and solid state ionic devices. In the utilization of solid electrolytes, thin film forms have practical advantages. They will make the devices and batteries miniaturization which is particularly important for certain applications such as microelectronic devices, space programs, and integrated circuits of self-contained power. So preparation of thin films of solid electrolytes and studies of their surfaces are significant. There has been interest in the properties of amorphous ionic conductors, as glasses have acknowledged advantages over crystalline electrolytes, including physical isotropy, the absence of grain boundaries, and continuously-variable composition. Furthermore, many glasses based on silver halides have conductivities as high as 10 Scm-1 at room temperature. So we have chosen the quaternary system AgI-Ag2O-P2O5-B2O3 as the basic materials, prepared thin films, studied their properties, and constructed thin film electrolytic batteries.

  8. Continued Statin Prescriptions After Adverse Reactions and Patient Outcomes: A Cohort Study.

    Science.gov (United States)

    Zhang, Huabing; Plutzky, Jorge; Shubina, Maria; Turchin, Alexander

    2017-08-15

    Many patients discontinue statin treatment, often after having a possible adverse reaction. The risks and benefits of continued statin therapy after an adverse reaction are not known. To examine the relationship between continuation of statin therapy (any prescription within 12 months after an adverse reaction) and clinical outcomes. Retrospective cohort study. Primary care practices affiliated with 2 academic medical centers. Patients with a presumed adverse reaction to a statin between 2000 and 2011. Information on adverse reactions to statins was obtained from structured electronic medical record data or natural-language processing of narrative provider notes. The primary composite outcome was time to a cardiovascular event (myocardial infarction or stroke) or death. Most (81%) of the adverse reactions to statins were identified from the text of electronic provider notes. Among 28 266 study patients, 19 989 (70.7%) continued receiving statin prescriptions after the adverse reaction. Four years after the presumed adverse event, the cumulative incidence of the composite primary outcome was 12.2% for patients with continued statin prescriptions, compared with 13.9% for those without them (difference, 1.7% [95% CI, 0.8% to 2.7%]; P statin was prescribed after the adverse reaction, 2014 (26.5%) had a documented adverse reaction to the second statin, but 1696 (84.2%) of those patients continued receiving statin prescriptions. The risk for recurrent adverse reactions to statins could not be established for the entire sample. It was also not possible to determine whether patients actually took the statins. Continued statin prescriptions after an adverse reaction were associated with a lower incidence of death and cardiovascular events. Chinese National Key Program of Clinical Science, National Natural Science Foundation of China, and Young Scientific Research Fund of Peking Union Medical College Hospital.

  9. Oxidation of clean silicon surfaces studied by four-point probe surface conductance measurements

    DEFF Research Database (Denmark)

    Petersen, Christian Leth; Grey, Francois; Aono, M.

    1997-01-01

    We have investigated how the conductance of Si(100)-(2 x 1) and Si(111)-(7 x 7) surfaces change during exposure to molecular oxygen. A monotonic decrease in conductance is seen as the (100) surfaces oxidizes. In contract to a prior study, we propose that this change is caused by a decrease in sur...

  10. A climatological study of rural surface ozone in central Greece

    Directory of Open Access Journals (Sweden)

    P. D. Kalabokas

    2004-01-01

    Full Text Available Recent studies show that surface ozone levels at rural sites in Greece are generally high when compared with rural ozone measurements at northern European sites. The area of SE Europe, including Greece, is not very well monitored regarding rural ozone in comparison to central and northern Europe. In order to have the best possible picture of the rural surface ozone climatology in the area, based on the available data-sets of long-term continuous monitoring stations, the 10-year measurement records (1987-1996 of the Athens peripheral station of Liossia, (12 km N of the city center and the urban background station of Geoponiki (3 km W as well as the 4-year record (1996-1999 of the rural station of Aliartos (100 km NW of Athens, are analyzed in this paper. The data for Liossia and Geoponiki stations are screened for cases of strong airflow from rural areas (N-NE winds stronger than 5 m/s. The variation characteristics of the average rural ozone afternoon levels (12:00-18:00, with the best vertical atmospheric mixing, are mainly examined since these measurements are expected to be representative of the broader area. In all three stations there is a characteristic seasonal variation of rural ozone concentrations with lowest winter afternoon values at about 50 μg/m3 in December-January and average summer afternoon values at about 120 μg/m3 in July-August, indicating that high summer values are observed all over the area. The rural summer afternoon ozone values are very well correlated between the three stations, implying spatial homogeneity all over the area but also temporal homogeneity, since during the 13-year period 1987-1999 the rural afternoon ozone levels remained almost constant around the value of 120 μg/m3.

  11. Neural correlates of simple unimanual discrete and continuous movements: a functional imaging study at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Habas, Christophe; Cabanis, Emmanuel A. [Hopital des Quinze-Vingts, UPMC Paris 6, Service de NeuroImagerie, Paris (France)

    2008-04-15

    The cerebral and cerebellar network involved in unimanual continuous and discrete movements was studied in blood oxygenation level-dependent functional magnetic resonance imaging (fMRI) at 3 T. Seven healthy right-handed volunteers were scanned (1) while drawing a circle with the tip of the right index finger (continuous motor task), and (2) while drawing a triangle with the tip of the right index finger (discrete motor task). In both motor tasks, extensive activations were observed in the sensorimotor (M1/S1), parietal, prefrontal, insular, lateral occipital (LOC) and anterior cerebellar cortices. Subcortical activations within red, thalamic and lentiform nuclei were also detected. However, discrete movements were specifically followed by the recruitment of the left orbitofrontal cortex, right dentate nucleus and the second cerebellar homunculus (HVIII), and bilateral and stronger activation of the sensorimotor cortical areas, whereas continuous movements specifically activated the right prefrontal cortex and the lateral hemispherical part of the neocerebellum (crus 1). We confirm the findings of previous studies showing partly distinct neural networks involved in monitoring continuous and discrete movements, but we found new differential neural relays within the prefrontal, insular and neocerebellar cortices. (orig.)

  12. Continuation versus discontinuation of lithium in recurrent bipolar illness: a naturalistic study.

    Science.gov (United States)

    Biel, Matthew G; Peselow, Eric; Mulcare, Loretta; Case, Brady G; Fieve, Ron

    2007-08-01

    Lithium's efficacy in prophylaxis of mood episodes in bipolar disorder (BD) is well established in the clinical trial setting, but may be less robust in routine clinical practice. We compared illness recurrence in bipolar patients naturalistically continued on or discontinued from lithium after an extended period of clinical stability on lithium monotherapy, and evaluated other potential risk factors for relapse. We followed 213 patients who were stable for 2 years on lithium monotherapy following resolution of acute symptoms marking their last manic episode. Based upon patient preference and clinical judgment, 159 patients were continued on lithium monotherapy and 54 patients were slowly discontinued. Survival differences between the continued and discontinued groups were assessed using the Kaplan-Meier product limit method, and risk factors for relapse were evaluated in Cox proportional hazards regression. Patients continued on lithium prophylaxis experienced risk of recurrence equivalent to a third of that suffered by discontinued patients during the first year of treatment (0.15 versus 0.45), and significant survival differences persisted throughout follow-up. Median survival time to illness recurrence for patients continued on lithium was 7.33 years [95% confidence interval (CI) 5.67-9.67]; that for patients discontinued from lithium was 1.33 years (95% CI 0.33-2.33). After controlling for all significant covariates, lithium discontinuation was associated with a hazard ratio of 4.85. Inter-episode manic and depressive symptoms conferred increased risk for subsequent recurrence of illness in both groups, while lower lithium levels recorded during the two years of clinical stability preceding study onset were protective. Despite considerable rates of illness recurrence in both groups, those who continued on lithium sustained markedly lower rates of recurrence over a lengthy follow-up period. Lithium discontinuation in BD after successful maintenance monotherapy

  13. Clinical study on acute renal failure treated with continuous blood purification

    Institute of Scientific and Technical Information of China (English)

    Jie Luo

    2016-01-01

    Objective: To study the clinical effect of continuous blood purification on acute renal failure. Methods: A total of 46 patients with acute renal failure treated with continuous renal replacement therapy in our hospital from April 2011 to December 2015 were retro-spectively analyzed. Patients choosing continuous veno-venous hemofiltration (CVVH) mode were collected into CVVH group and patients choosing continuous venovenous hemodiafiltration (CVVHDF) mode were collected into CVVHDF group, and their general condition, hospitalization conditions and blood biochemical indexes were analyzed. Results: Before and after treatment, the voided volumes and APACHE II scores of patients in CVVHDF group and CVVH group showed no differences. After treatment, the voided volumes of patients in the two groups were all higher than those before treatment and their APACHE II scores were all lower than those before treatment. The duration of continuous renal replacement therapy and the hospital stays in ICU of patients in CVVHDF group were all shorter than those in CVVH group. In CVVHDF group, the ratios of mechanical ventilation and death and the total hospitalization time had no sig-nificant differences with those in CVVH group. After treatment, the contents of blood urea nitrogen, serum creatinine, uric acid, β2 microglobulin, glutamic-pyruvic trans-aminase, aspartate transaminase, lactic dehydrogenase and creatine kinase isoenzyme of patients in CVVHDF group were all lower than those in CVVH group. Conclusions: Continuous blood purification therapy possesses exact curative effect on acute renal failure. The cleanup effect of CVVHDF mode on solutes and its protective effect on heart and liver were all superior to those of CVVH mode.

  14. A study of continuing nurse education in Malta: the importance of national context.

    Science.gov (United States)

    Adami, Maria Fenech; Kiger, Alice

    2005-01-01

    The literature recommends that in the light of the constant changes in the contexts in which nurses perform [Buerhaus, P., 1997. The future of the nurse labour market. Image 29(4), 313-318], nurse education systems should incorporate specialised and continuing education [Lenera, V., 1987. The Nurse and the Future: Role and Function. In: Health Care and Nurse Education in the 21st Century. Commission of the European Communities, Brussels; Castledine, G., McGee, P., 1998. Advanced and Specialist Nursing Practice, Blackwell Science Ltd., Oxford; Chiarella, M., 1998. Developing the credibility of continuing education. Nurse Education Today 10, 70-73 ]. Using a qualitative approach, the research study reported in this article explored views of student and qualified nurses in Malta about such educational opportunities. Data were collected using questionnaires administered by post to student and qualified nurses in Malta (n=172) [Fenech Adami, M., 2002. An exploratory study of the adequacy of the nurse education system in Malta. PhD Thesis. University of Aberdeen.]. In congruence with the literature, the findings revealed widespread support for and interest in specialised and continuing education in general [Nolan, M., 1994. Continuing professional education: identifying the characteristics an effective system. Journal of Advanced Nursing 22, 551-560; Wilson-Barnett, J., 1994. Evaluating the clinical nurse specialist - a review. International Journal of Nursing Studies 31(6), 561-571]. However, some of the findings challenge that which is recommended in the literature. The findings should contribute to the effective development of specialised and continuing education opportunities in Malta. Moreover, by their divergence from the literature, these findings illustrate that nurse education should always be planned against a backdrop of the context in which it is to be delivered. In turn, the findings point out the importance of researching education within specific contexts

  15. A surface study of mercury-cadmium-telluride

    Science.gov (United States)

    Lopes, V. C.

    1985-12-01

    Single crystals of Hg (sub 1-x) Cd (sub x) Te were studied to determine how changes in the surface conditions affected electrical properties, infrared detector grade material was used to examine the effects of changes in the surface charge density on electrical l/f noise. The surface charge density which was controlled by the pH of the aqueous solution was measured in a zeta meter which operated much like a Millikan oil drop experiment. The electrophoresis zeta potential measurements on (HgCd)Te have identified the active surface oxide as TeO2 and has also revealed information on the surface chemistry. Electrical l/f noise in-(HgCd)Te was found to be dominated by bulk and not surface effects at room temperature. Laser Raman and Auger spectroscopy were used to assess mechanical surface damage and anodic oxide composition.

  16. Preliminary study on aerobic granular biomass formation with aerobic continuous flow reactor

    Science.gov (United States)

    Yulianto, Andik; Soewondo, Prayatni; Handajani, Marissa; Ariesyady, Herto Dwi

    2017-03-01

    A paradigm shift in waste processing is done to obtain additional benefits from treated wastewater. By using the appropriate processing, wastewater can be turned into a resource. The use of aerobic granular biomass (AGB) can be used for such purposes, particularly for the processing of nutrients in wastewater. During this time, the use of AGB for processing nutrients more reactors based on a Sequencing Batch Reactor (SBR). Studies on the use of SBR Reactor for AGB demonstrate satisfactory performance in both formation and use. SBR reactor with AGB also has been applied on a full scale. However, the use use of SBR reactor still posses some problems, such as the need for additional buffer tank and the change of operation mode from conventional activated sludge to SBR. This gives room for further reactor research with the use of a different type, one of which is a continuous reactor. The purpose of this study is to compare AGB formation using continuous reactor and SBR with same operation parameter. Operation parameter are Organic Loading Rate (OLR) set to 2,5 Kg COD/m3.day with acetate as substrate, aeration rate 3 L/min, and microorganism from Hospital WWTP as microbial source. SBR use two column reactor with volumes 2 m3, and continuous reactor uses continuous airlift reactor, with two compartments and working volume of 5 L. Results from preliminary research shows that although the optimum results are not yet obtained, AGB can be formed on the continuous reactor. When compared with AGB generated by SBR, then the characteristics of granular diameter showed similarities, while the sedimentation rate and Sludge Volume Index (SVI) characteristics showed lower yields.

  17. Continuation of Health Behaviors: Psychosocial Factors Sustaining Drinking Water Chlorination in a Longitudinal Study from Chad

    Directory of Open Access Journals (Sweden)

    Jonathan Lilje

    2016-11-01

    Full Text Available Behavior that has changed following promotion campaigns is usually not maintained at its initial level. Psychosocial factors for initiating behavior are often not the same as for the continuation of health behaviors such as water treatment and are much less understood. Better knowledge of factors for behavioral continuation would help to improve programs, both in the design of strategies for sustainable behavior change and by defining stronger criteria for the evaluation of sustainability. This study compared the mindsets of caregivers who continuously performed household drinking water treatment over time with individuals that stopped doing so in a population sample from Chad. Several factors from health psychology based on the Risks, Attitudes, Norms, Abilities, and Self-Regulation (RANAS model were used to compare the two groups and examine their differing development. Normative factors such as others’ behavior, personal obligation, social support and discourse, perceived self-efficacy convictions, action control, and intention best discriminated between the two groups and developed significantly more positively over time for continuers of water treatment. These factors should be considered when designing future interventions intended to lead to sustainable behavior change.

  18. Breakdown of continuity in public mental healthcare in the Netherlands: a longitudinal case study

    Directory of Open Access Journals (Sweden)

    André Wierdsma

    2011-09-01

    Full Text Available Introduction: Continuity of care for long-term service-dependent patients in the public mental health system requires intensive collaboration between all agencies involved. Understanding the ways in which various aspects of continuity of care interact may reveal help to find out more about how care de­livered over time improves outcomes. Case study: Based on medical records, an addicted couple was monitored for number and type of contacts with health and social services. Over the years, 81 social workers or nurses, spread over 25 health and social services, have been involved in the rehabilitation process. Breakdown of continuity of care is linked to lack of information, missing procedures and guidelines, fragile relationships with the patient, and a reluctant public health approach. Conclusion: Prominent among relevant factors is the absence of protocols governing the transfer of patients between the various links in the continuum of mental healthcare services. High-quality follow-up after admission is partly a matter of professional principle in ensuring that problems in the chain of services are discussed. Case presen­tation in psychiatric journals should give syste­matic at­ten­tion to sources of error in continuity of mental health­care.

  19. Arctic Marine Water Isotope Characteristics: In-situ, Continuous Surface and Water Column Isoscapes (δ18O and δ2H) and Linkages into the Marine Food Web

    Science.gov (United States)

    Welker, J. M.; Klein, E. S.; Collins, E.; Iken, K.; Hopcroft, R. R.; Norcross, B.

    2016-12-01

    The Arctic is under going rapid and profound sea ice, temperature, food web, ocean current, precipitation and synoptic weather changes. Delineating these changes requires a suite of tools, especially those that have the ability to depict the interactive nature of the marine system. Understanding the marine water isotope cycle is paramount to recognizing the unique isotopic properties of this region and to characterize possibly the reorganization of the Arctic. The Arctic marine water isotope system has been primarily examined with shore-based stations and or episodic station sampling; without continuous surface water sampling in combination with station-specific water column and organismic measurements. New technologies that allow in situ and continuous water isotope measurements (vapor and liquid) and the integration of inorganic and organic water isotope geochemistry provide a means to reveal in more detail the fundamental traits of the Arctic marine water isotope system. In July and August of 2016, we are measuring seawater surface (8 m depth) isotopes (δ18O and δ2H) in-situ and continuously (Picarro CWS system) along a research transect (60oN to 77oN) from the Gulf of Alaska to the Arctic Ocean Basin. These continuous surface water isotope measurements are being combined with periodic water column isotope profiling and corresponding organic δ18O and δ2H measurements of pelagic and benthic organisms (microbes to fish) to depths of up to 2600m. We measured surface seawater δ18O that from -1‰ to -6‰; while seawater profiles followed vertical separation in the water column; possibly reflecting divergent currents of the Arctic. Station based δ18O and δ2H values of surface water did not vary by more than 1‰ δ18O over the course of our 24-36 hour sampling periods. The δ18O and δ2H values of marine organism throughout the water column and by trophic level will be analyzed and a seawater-food web model will be developed in addition to surface and water

  20. Modeling the field control of the surface electroclinic effect near continuous and first-order smectic-A* to smectic-C* transitions.

    Science.gov (United States)

    Zappitelli, Kara; Hipolite, Dana N; Saunders, Karl

    2014-02-01

    We present and analyze a model for the combination of bulk and surface electroclinic effects in the smectic-A* (Sm-A*) phase near a Sm-A*-Sm-C* transition. As part of our analysis we calculate the dependence of the surface tilt on external electric field and show that it can be eliminated, or even reversed from its zero-field value, as demonstrated in previous experimental work on a system (W415) with a continuous Sm-A*-Sm-C* transition. We also analyze, for the first time, the combination of bulk and surface electroclinic effects in systems with a first-order Sm-A*-Sm-C* transition. The variation of surface tilt with electric field in this case is much more dramatic, with discontinuities and hysteresis. With regard to technological, e.g., display, applications, this could be a feature to be avoided or potentially exploited. Near each type of Sm-A*-Sm-C* transition we obtain the temperature dependence of the field required to eliminate surface tilt. Additionally, we analyze the effect of varying the system's enantiomeric excess, showing that it strongly affects the field dependence of surface tilt, in particular, near a first-order Sm-A*-Sm-C* transition. In this case, increasing enantiomeric excess can change the field dependence of surface tilt from continuous to discontinuous. Our model also allows us to calculate the variation of layer spacing in going from surface to bulk, which in turn allows us to estimate the strain resulting from the difference between the surface and bulk layer spacing. We show that for certain ranges of applied electric field, this strain can result in layer buckling, which reduces the overall quality of the liquid crystal cell. For de Vries materials, with small tilt-induced change in layer spacing, the induced strain for a given surface tilt should be smaller. However, we argue that this may be offset by the fact that de Vries materials, which typically have Sm-A*-Sm-C* transitions near a tricritical point, will generally have larger

  1. Conformation of bovine submaxillary mucin layers on hydrophobic surface as studied by biomolecular probes

    DEFF Research Database (Denmark)

    Pakkanen, Kirsi I.; Madsen, Jan Busk; Lee, Seunghwan

    2015-01-01

    In the present study, the conformational changes of bovine submaxillary mucin (BSM) adsorbed on a hydrophobic surface (polystyrene (PS)) as a function of concentration in bulk solution (up to 2mg/mL) have been investigated with biomolecular probe-based approaches, including bicinchoninic acid (BCA...... solution. Adsorbed masses of BSM onto hydrophobic surface, as probe by BCA, showed a continuously increasing trend up to 2mg/mL. But, the signals from EIA and ELLA, which probe the concentration of available unglycosylatedC-terminals and the central glycosylated regions, respectively, showed complicated...... non-linear responses with increasing surface concentration. The results from this study support the conventional amphiphilic, triblock model of BSM in the adsorption onto hydrophobic surface from aqueous solution.The biomolecular probe-based approaches employed in this study, however, provided further...

  2. Phase I study of continuous weekly dosing of dimethylamino benzoylphenylurea (BPU) in patients with solid tumours.

    Science.gov (United States)

    Messersmith, Wells A; Rudek, Michelle A; Baker, Sharyn D; Zhao, Ming; Collins, Connie; Colevas, A Dimitrios; Donehower, Ross C; Carducci, Michael A; Wolff, Antonio C

    2007-01-01

    A phase I study of dimethylamino benzoylphenylurea (BPU), a tubulin inhibitor, was performed using a weekly continuous schedule. Patients with refractory solid tumours received oral BPU once weekly without interruption at doses ranging from 5 to 320mg using an accelerated titration design. Nineteen subjects received 54 cycles of BPU. Early pharmacokinetic findings of decreased clearance with increasing dose and plasma accumulation led to the expansion of the 320mg dose level. Two subjects then developed late haematologic dose-limiting toxicities (DLTs) that were associated with the highest plasma exposure to BPU and metabolites. Study enrollment resumed at dose 150mg with real-time pharmacokinetic monitoring. Seven additional subjects (6 evaluable) were treated for a median of 2 cycles (range 1.5-4) without further myelotoxicity. A long half-life and accumulation of BPU and active metabolites were observed, recommending against a continuous administration. Weekly oral BPU therapy should be further tested using an interrupted schedule.

  3. A study of tumour growth based on stoichiometric principles: a continuous model and its discrete analogue.

    Science.gov (United States)

    Saleem, M; Agrawal, Tanuja; Anees, Afzal

    2014-01-01

    In this paper, we consider a continuous mathematically tractable model and its discrete analogue for the tumour growth. The model formulation is based on stoichiometric principles considering tumour-immune cell interactions in potassium (K (+))-limited environment. Our both continuous and discrete models illustrate 'cancer immunoediting' as a dynamic process having all three phases namely elimination, equilibrium and escape. The stoichiometric principles introduced into the model allow us to study its dynamics with the variation in the total potassium in the surrounding of the tumour region. It is found that an increase in the total potassium may help the patient fight the disease for a longer period of time. This result seems to be in line with the protective role of the potassium against the risk of pancreatic cancer as has been reported by Bravi et al. [Dietary intake of selected micronutrients and risk of pancreatic cancer: An Italian case-control study, Ann. Oncol. 22 (2011), pp. 202-206].

  4. The Discourse Semantics of Attitudinal Relations: Continuing the Study of Lexis

    Directory of Open Access Journals (Sweden)

    Дж Р Мартин

    2017-12-01

    Full Text Available This paper explores some aspects of the problem of categorizing attitudinal relations in English, as part of a description of evaluation informed by systemic functional linguistics (SFL - appraisal. It reviews paradigmatic and syntagmatic orientations to lexis within this tradition, and the development of typological and topological representations of systemic relations. Corpus based argumentation is considered in relation to work on evaluation by Bednarek 2008; and proposals for continuing the study of lexis are suggested, focusing on resources for negotiating sadness and negative reactions to behavior (e.g. embarrassed , ashamed and the affordances of topological representation. The paper highlights the possibilities and challenges involved in continuing the study of lexis in descriptions using SFL as their informing theory.

  5. Study on the Needs of Continuing Vocational Training for Social Workers in Bulgaria

    Directory of Open Access Journals (Sweden)

    Preslava Dimitrova

    2017-06-01

    Full Text Available The occupation of the social worker in modern times is challenged by the dynamically changing economic and social environment, growing requirements to their qulifications and competences and the needs of gaining new skills and permanen development and improvement. The aim of the presented study of defining the needs for continuing vocational training of specialists providing social services is to provide recommendations regarding the need of training for skills contributing to the increase in the degree of correspondence between labor supply and demand on the labor market, contributing to the improvement of the quality of the labor force in the country as a competitive factor with an increasing importance for successful economic development. The investigation and the specific examples discussed can be a solid basis for future studies and development of models for improvement the system of continuing and vocational training for acquiring the needed knowledge, skills and competences for effective work.

  6. Optimal Conditions for Continuous Immobilization of Pseudozyma hubeiensis (Strain HB85A Lipase by Adsorption in a Packed-Bed Reactor by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Roberta Bussamara

    2012-01-01

    Full Text Available This study aimed to develop an optimal continuous process for lipase immobilization in a bed reactor in order to investigate the possibility of large-scale production. An extracellular lipase of Pseudozyma hubeiensis (strain HB85A was immobilized by adsorption onto a polystyrene-divinylbenzene support. Furthermore, response surface methodology (RSM was employed to optimize enzyme immobilization and evaluate the optimum temperature and pH for free and immobilized enzyme. The optimal immobilization conditions observed were 150 min incubation time, pH 4.76, and an enzyme/support ratio of 1282 U/g support. Optimal activity temperature for free and immobilized enzyme was found to be 68°C and 52°C, respectively. Optimal activity pH for free and immobilized lipase was pH 4.6 and 6.0, respectively. Lipase immobilization resulted in improved enzyme stability in the presence of nonionic detergents, at high temperatures, at acidic and neutral pH, and at high concentrations of organic solvents such as 2-propanol, methanol, and acetone.

  7. A Feasibility Study for Life Signs Monitoring via a Continuous-Wave Radar

    Directory of Open Access Journals (Sweden)

    Francesco Soldovieri

    2012-01-01

    Full Text Available We present a feasibility study for life signs detection using a continuous-wave radar working in the band around 4 GHz. The data-processing is carried out by using two different data processing approaches, which are compared about the possibility to characterize the frequency behaviour of the breathing and heartbeat activity. The two approaches are used with the main aim to show the possibility of monitoring the vital signs activity in an accurate and reliable way.

  8. Phase I Study of Continuous Weekly Dosing of Dimethylamino Benzoylphenylurea (BPU) in Patients with Solid Tumours

    OpenAIRE

    Messersmith, Wells A.; Rudek, Michelle A.; Baker, Sharyn D.; Zhao, Ming; Collins, Connie; Colevas, A. Dimitrios; Donehower, Ross C.; Carducci, Michael A.; Wolff, Antonio C.

    2006-01-01

    A phase I study of Dimethylamino Benzoylphenylurea (BPU), a tubulin inhibitor, was performed using a weekly continuous schedule. Patients with refractory solid tumours received oral BPU once weekly without interruption at doses ranging from 5 to 320mg using an accelerated titration design. Nineteen subjects received 54 cycles of BPU. Early pharmacokinetic findings of decreased clearance with increasing dose and plasma accumulation led to the expansion of the 320mg dose level. Two subjects the...

  9. Proposal for continuing studies on lead/scintillating fibres calorimetry (LFC)

    CERN Document Server

    Anzivino, Giuseppina; Bari, G; Basile, M; Bellagamba, L; Bencheikh, C; Boscherini, D; Bruni, G; Bruni, P; Buzuloiu, V; Cara Romeo, G; Chiarini, M; Cifarelli, Luisa; Cindolo, F; Ciralli, F; Contin, A; Dardo, M; De Pasquale, S; DeSalvo, R; Frasconi, F; Gheorghe, A; Giusti, P; Hao, E; Iacobucci, G; Laurenti, G; Lundin, M; Maccarrone, G D; Margotti, A; Massam, Thomas; Mondardini, M R; Nania, R; Peskov, Vladimir; Sartorelli, G; Scioni, M; Timellini, R; Wang, Y; Xu, C; You, K; Zichichi, Antonino; CERN. Geneva. Detector Research and Development Committee

    1991-01-01

    Starting from the results obtained in the framework of the LAA Project 2B, we propose a continuation of the R&D on lead/scintillating fibres calorimetry ("spaghetti calorimetry"), including further tests on the old calorimeter prototypes and the construction and testing of new prototypes. The main results we pursue concern the performances of a projective calorimeter built with new, cheaper techniques and the radiation hardness of the scintillating fibres; the optimization of a preshower detector system is also studied.

  10. Nurses in emotional competence: exploratory study on population of continued care national network

    OpenAIRE

    Lopes, Tânia; Veiga-Branco, Augusta; Baptista, Gorete

    2014-01-01

    The relevance of this study - the first empirical research (to our knowledge) in Continued Care National Network (RCNN) context - emerge to understand the role of emotions in workplace behaviour (Côté, 2005; Austin, Dore & Donovan, 2008; Liu et al. 2008; Barsade, Ramarajan, Burack, 2008), but here, with terminally ill people and great physical and psychological weakness. Recent scientific literature is exposing a significatly negative correlations between Emotional Intelligence...

  11. Continuous Assessment: A Preliminary Study of Student Engagement in the Assessment Process

    OpenAIRE

    Nevin, Edmund; Mageean, Eileen; Llorens, Marisa

    2013-01-01

    This paper provides an objective analysis of student engagement with continuous assessment over a three year period. The results of two groups of students from different stages of a modularised level seven engineering programme were examined. As both groups had taken modules where they studied numerical differentiation, this topic was selected and the corresponding assessment results and attendance of both groups were analysed. Two assessment methods were used to evaluate student engagemen...

  12. Contact angle hysteresis on randomly rough surfaces: a computational study.

    Science.gov (United States)

    David, Robert; Neumann, A Wilhelm

    2013-04-09

    Wetting is important in many applications, and the solid surfaces being wet invariably feature some amount of surface roughness. A free energy-based computational simulation is used to study the effect of roughness on wetting and especially contact angle hysteresis. On randomly rough, self-affine surfaces, it is found that hysteresis depends primarily on the value of the Wenzel roughness parameter r, increasing in proportion with r - 1. Micrometer-level roughness causes hysteresis of a few degrees.

  13. Controlled surface neutralization: A quantitative approach to study surface charging in photoemission

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S. [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Mukherjee, M. [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)], E-mail: manabendra.mukherjee@saha.ac.in

    2007-02-15

    Photons when used to probe poorly conducting materials induce emission of secondary electrons that are inadequately compensated from the sample ground giving rise to a phenomenon commonly known as sample charging. In case of photoemission spectroscopy of an insulating material the data obtained from the charged surface are accordingly distorted. Here we have used a controlled neutralization technique to obtain photoemission data from continuously varying equilibrium charging conditions from two dissimilar insulating polymeric systems. A quantitative scheme for data analysis has been developed to demonstrate systematic behavior in the apparently distorted spectra and the charging peak shift has been described by an effective model. It is shown that the neutralization responses are non-linear for both the systems and possess intrinsic similarity. Around a critical electron flux the neutralization of the samples appears to occur through the percolation of homogeneously dispersed surface domains.

  14. Biocompatibility and Surface Studies of Microwave CVD Diamond Films

    Science.gov (United States)

    Davis, Brian; Garguilo, J. M.; Koeck, F. A. M.; Nemanich, R. J.; Price, K. J.

    2002-03-01

    The structure and surface properties of a variety of diamond and diamond like carbon films were studied at the nano-scale, in an attempt to assess the biocompatibility of these surfaces. The process of microwave chemical vapor deposition was used to deposit undoped diamond, nitrogen doped diamond, diamond with a titanium monolayer, and diamond-like carbon samples. The contact angles of de-ionized water droplets on the surface of the samples were measured to analyze the surface energy of each film. The rms roughness values of the diamond films measured by atomic force microscopy were also used in determining surface characteristics. Surface treatments of hydrogen passivation, and oxidization were applied to the surface of each film. Hydrogen passivation of the undoped diamond, and nitrogen doped diamond surfaces increases the contact angle on average 30 degrees. Oxidation of the surface decreases the contact angle on average 20 degrees. The surface treatments did not significantly change the contact angle of the diamond like carbon films. Protein adsorption is the first event to take place at a tissue/material interface of an implant into the body, and fibrinogen is the major surface protein, which initiates coagulation and inflammation in the body. The adsorption of fibrinogen was used as an indicator of the biocompatibility of these diamond materials. Fibrinogen was applied to the diamond, and diamond like carbon films. A correlation between contact angle/surface energy, roughness, and the fibrinogen adsorption of these diamond surfaces is reported. There was no significant change in the contact angles following the application of fibrinogen to the surface of the films. This could indicate the biocompatibility of the diamond films. This work supported by the NSF REU program at NCSU and a Physical Sciences Student Research grant from MSU.

  15. Heat transfer in a couple stress fluid over a continuous moving surface with internal hat generation and convective boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Tasawar [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Mathematics; King Saud Univ., Riyadh (Saudi Arabia). Dept. of Physics; Iqbal, Zahid [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Mathematics; Qasim, Muhammad [COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan). Dept. of Mathematics; Aldossary, Omar M. [King Saud Univ., Riyadh (Saudi Arabia). Dept. of Physics

    2012-05-15

    This investigation reports the boundary layer flow and heat transfer characteristics in a couple stress fluid flow over a continuos moving surface with a parallel free stream. The effects of heat generation in the presence of convective boundary conditions are also investigated. Series solutions for the velocity and temperature distributions are obtained by the homotopy analysis method (HAM). Convergence of obtained series solutions are analyzed. The results are obtained and discussed through graphs for physical parameters of interest. (orig.)

  16. Toward continuous LC-MS analysis: surface modification of magnetic microparticles with TiO2 for phosphate adsorption.

    Science.gov (United States)

    Akutagawa, Issei; Akiyama, Yoshitake; Takahashi, Yutaka; Iijima, Motoyuki; Okada, Yohei; Kamiya, Hidehiro; Chiba, Kazuhiro

    2014-01-01

    Continuous liquid chromatography-mass spectrometry (LC-MS) analysis was successfully demonstrated by using magnetic TiO2/Fe3O4 microparticles at the desalination interface. The particles could be prepared easily even on a practical scale at sufficient quality for efficient phosphate adsorption. Not only phosphate but several biomolecules were adsorbed onto the particles in a non-specific manner. Such samples could still be detected effectively in MS because the removal of phosphate derived from the LC eluent enhanced sample ionization and resulted in a significant reduction of phosphate cluster ions.

  17. Studying Polymer Transport on Soft and Hard Surfaces

    Science.gov (United States)

    Kumar, Sanat

    2007-03-01

    We have employed experiments and simulations to understand the factors controlling the transport of polymers on surfaces. From an experimental viewpoint we have focused on the transport of DNA (single stranded) on lipid bilayers. We show that this behavior is slaved to the mobility of the lipids. More surprisingly, it appears that the transport of molecules adsorbed on surfaces follows the same dependence on lipid mobility as for molecules incorporated into the lipid layer. The ability to control this surface diffusion through the introduction of posts or varying the strength of adsorption (by the use of an AC field normal to the surfaces) will also be studied. Theoretically we have used molecular dynamics simulations of a polymer chain of length N dissolved in explicit solvent and adsorbed as a pancake at the solid-liquid interface to discriminate between respective influences on surface diffusion of hydrodynamics and adsorption energetics. Only for analytically-smooth surfaces do we observe a strong influence of hydrodynamics; the polymer lateral diffusion constant, D, scales as D 1/N^3/4, more weakly than for implicit solvent. For atomistic surface corrugation with uniform surface chemical makeup, D 1/N instead. This suggests that while we can understand the results for diffusion on lipid surfaces, more recent experimental observations of stronger N dependence for diffusion on hard solid surfaces originate not in hydrodynamic interactions but in spatially patchy energetic interactions.

  18. Surface roughness measurement using dichromatic speckle pattern: an experimental study.

    Science.gov (United States)

    Fujii, H; Lit, J W

    1978-09-01

    Surface roughness is studied experimentally by making use of the statistical properties of dichromatic speckle patterns. The rms intensity difference between two speckle patterns produced by two argon laser lines are analyzed in the far field as functions of the object surface roughness and the difference in the two wavenumbers of the illuminating light. By applying previously derived formulas, the rms surface roughness is obtained from rms intensity differences. Glass and metal rough surfaces are used. Other than the scattering arrangement, the experimental setup has a simple spectrometric system and an electronic analyzing circuit.

  19. Studies of liquid metal surfaces using Auger spectroscopy

    Science.gov (United States)

    Hardy, S.; Fine, J.

    1982-01-01

    The surface composition of liquid gallium-tin alloys is studied in an Auger electron spectrometer as a function of bulk composition and temperature. The sessile drop samples are cleaned by argon ion bombardment sputtering of the liquid. This technique produces surfaces that are entirely free of impurities within the sensitivity of the spectrometer and remain so for many days. Tin is found to be strongly adsorbed at the liquid-vacuum interface. Surface concentrations based on Auger measurements are found to be in reasonably good agreement with values calculated from surface tension measurements interpreted in terms of a monolayer depth distribution model for the adsorbed tin.

  20. Surface oxidation of cobalt nanoparticles studied by Mossbauer spectroscopy

    DEFF Research Database (Denmark)

    Bødker, Franz; Mørup, Steen; Charles, S.W.

    1999-01-01

    The surface oxide formed on cobalt nanoparticles has been studied by Mossbauer emission spectroscopy. Exposure of the cobalt particles to oxygen at room temperature was found to result in the formation of a relatively well-ordered surface oxide with Mossbauer parameters similar to those of CoO....

  1. Surface magnetism studied by polarized light emission after He+ scattering

    NARCIS (Netherlands)

    Manske, J; Dirska, M; Lubinski, G; Schleberger, M; Narmann, A; Hoekstra, R

    1997-01-01

    Surface magnetism is studied by means of an ion beam of low energy (2-15 keV) scattered off the surface under grazing incidence conditions. During the scattering, a small fraction of the ions is neutralized into excited states which decay subsequently by light emission. The circular polarization of

  2. Facial recognition and laser surface scan: a pilot study

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Clausen, Maja-Lisa; Kristoffersen, Agnethe May

    2009-01-01

    Surface scanning of the face of a suspect is presented as a way to better match the facial features with those of a perpetrator from CCTV footage. We performed a simple pilot study where we obtained facial surface scans of volunteers and then in blind trials tried to match these scans with 2D...

  3. Nonlinear-damping continuation of the nonlinear Schr\\"odinger equation - a numerical study

    CERN Document Server

    Fibich, G

    2011-01-01

    We study the nonlinear-damping continuation of singular solutions of the critical and supercritical NLS. Our simulations suggest that for generic initial conditions that lead to collapse in the undamped NLS, the solution of the weakly-damped NLS $$ i\\psi_t(t,\\X)+\\Delta\\psi+|\\psi|^{p-1}\\psi+i\\delta|\\psi|^{q-1}\\psi=0,\\qquad0<\\delta \\ll 1, $$ is highly asymmetric with respect to the singularity time, and the post-collapse defocusing velocity of the singular core goes to infinity as the damping coefficient $\\delta$ goes to zero. In the special case of the minimal-power blowup solutions of the critical NLS, the continuation is a minimal-power solution with a higher (but finite) defocusing velocity, whose magnitude increases monotonically with the nonlinear damping exponent $q$.

  4. THEORETICAL AND EXPERIMENTAL STUDY ON THE PRESSURE AND VACUUM CONTINUOUS CONTROL SYSTEM BASED ON HYBRID PUMP

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel pressure and vacuum continuous control system, which adopts a hybrid pump as pressure and vacuum source, is presented. The mathematical model of the system is developed. The theoretical simulation and analysis on the system are implemented in order to study the relationships among the characteristics, parameters and working points of the system. The experimental investigations on the system characteristics are presented with the adoption of a fuzzy-PID controller. The simulation and experimental results indicate that the pressure and vacuum continuous control system based on hybrid pump has good dynamic and static performance, strong robustness and satisfactory adaptability to various system parameters. According to the results, system can successfully gain high accuracy and fast response signal. Also, the mathematical model of system is also testified by the experimental results.

  5. Study on hydrophilicity of polymer surfaces improved by plasma treatment

    Science.gov (United States)

    Lai, Jiangnan; Sunderland, Bob; Xue, Jianming; Yan, Sha; Zhao, Weijiang; Folkard, Melvyn; Michael, Barry D.; Wang, Yugang

    2006-03-01

    Surface properties of polycarbonate (PC), polypropylene (PP), polyethylene terephthalate (PET) samples treated by microwave-induced argon plasma have been studied with contact angle measurement, X-ray photoelectron spectroscopy (XPS) and scanned electron microscopy (SEM). It is found that plasma treatment modified the surfaces both in composition and roughness. Modification of composition makes polymer surfaces tend to be highly hydrophilic, which mainly depended on the increase of ratio of oxygen-containing group as same as other papers reported. And this experiment further revealed that C dbnd O bond is the key factor to the improvement of the hydrophilicity of polymer surfaces. Our SEM observation on PET shown that the roughness of the surface has also been improved in micron scale and it has influence on the surface hydrophilicity.

  6. Study on hydrophilicity of polymer surfaces improved by plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lai Jiangnan [Key Laboratory of Heavy Ion Physics, Peking University, MOE, Beijing (China); Sunderland, Bob [Gray Cancer Institute, Mount Vernon Hospital, Northwood, Middlesex (United Kingdom); Xue Jianming [Key Laboratory of Heavy Ion Physics, Peking University, MOE, Beijing (China); Yan, Sha [Key Laboratory of Heavy Ion Physics, Peking University, MOE, Beijing (China); Zhao Weijiang [Key Laboratory of Heavy Ion Physics, Peking University, MOE, Beijing (China); Folkard, Melvyn [Gray Cancer Institute, Mount Vernon Hospital, Northwood, Middlesex (United Kingdom); Michael, Barry D. [Gray Cancer Institute, Mount Vernon Hospital, Northwood, Middlesex (United Kingdom); Wang Yugang [Key Laboratory of Heavy Ion Physics, Peking University, MOE, Beijing (China)]. E-mail: ygwang@pku.edu.cn

    2006-03-15

    Surface properties of polycarbonate (PC), polypropylene (PP), polyethylene terephthalate (PET) samples treated by microwave-induced argon plasma have been studied with contact angle measurement, X-ray photoelectron spectroscopy (XPS) and scanned electron microscopy (SEM). It is found that plasma treatment modified the surfaces both in composition and roughness. Modification of composition makes polymer surfaces tend to be highly hydrophilic, which mainly depended on the increase of ratio of oxygen-containing group as same as other papers reported. And this experiment further revealed that C=O bond is Key factor to the improvement of the hydrophilicity of polymer surfaces. Our SEM observation on PET shown that the roughness of the surface has also been improved in micron scale and it has influence on the surface hydrophilicity.

  7. A molecular dynamics study on surface properties of supercooled water

    Institute of Scientific and Technical Information of China (English)

    L(U) Yongjun; WEI Bingbo

    2006-01-01

    Molecular dynamics simulations were performed to study the surface properties of water in a temperature range from 228 to 293 K by using the extended simple point charge (SPC/E) and four-site TIP4P potentials. The calculated surface tension increases with the decrease of temperature, and moreover the slopes of the surface tension-temperature curves show a weak rise below 273 K, whereas no obvious anomalies appear near 228 K, which accords with the previous experiments. Compared with the measured values, the SPC/E potential shows a good agreement, and the TIP4P potential scription of the surface structure of supercooled water for the SPC/E. When simulating the orientational distributions of water molecules near the surface, the SPC/E potential produces higher ordering and larger surface potentials than the TIP4P potential.

  8. Chemical treatment of zinc surface and its corrosion inhibition studies

    Indian Academy of Sciences (India)

    S K Rajappa; T V Venkatesha; B M Praveen

    2008-02-01

    The surface treatment of zinc and its corrosion inhibition was studied using a product (BTSC) formed in the reaction between benzaldehyde and thiosemicarbozide. The corrosion behaviour of chemically treated zinc surface was investigated in aqueous chloride–sulphate medium using galvanostatic polarization technique. Zinc samples treated in BTSC solution exhibited good corrosion resistance. The measured electrochemical data indicated a basic modification of the cathode reaction during corrosion of treated zinc. The corrosion protection may be explained on the basis of adsorption and formation of BTSC film on zinc surface. The film was binding strongly to the metal surface through nitrogen and sulphur atoms of the product. The formation of film on the zinc surface was established by surface analysis techniques such as scanning electron microscopy (SEM–EDS) and Fourier transform infrared spectroscopy (FTIR).

  9. Controlling Multivalent Binding through Surface Chemistry: Model Study on Streptavidin

    Science.gov (United States)

    2017-01-01

    Although multivalent binding to surfaces is an important tool in nanotechnology, quantitative information about the residual valency and orientation of surface-bound molecules is missing. To address these questions, we study streptavidin (SAv) binding to commonly used biotinylated surfaces such as supported lipid bilayers (SLBs) and self-assembled monolayers (SAMs). Stability and kinetics of SAv binding are characterized by quartz crystal microbalance with dissipation monitoring, while the residual valency of immobilized SAv is quantified using spectroscopic ellipsometry by monitoring binding of biotinylated probes. Purpose-designed SAv constructs having controlled valencies (mono-, di-, trivalent in terms of biotin-binding sites) are studied to rationalize the results obtained on regular (tetravalent) SAv. We find that divalent interaction of SAv with biotinylated surfaces is a strict requirement for stable immobilization, while monovalent attachment is reversible and, in the case of SLBs, leads to the extraction of biotinylated lipids from the bilayer. The surface density and lateral mobility of biotin, and the SAv surface coverage are all found to influence the average orientation and residual valency of SAv on a biotinylated surface. We demonstrate how the residual valency can be adjusted to one or two biotin binding sites per immobilized SAv by choosing appropriate surface chemistry. The obtained results provide means for the rational design of surface-confined supramolecular architectures involving specific biointeractions at tunable valency. This knowledge can be used for the development of well-defined bioactive coatings, biosensors and biomimetic model systems. PMID:28234007

  10. TOLNET – A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Directory of Open Access Journals (Sweden)

    Newchurch Michael J.

    2016-01-01

    Full Text Available Ozone lidars measure continuous, high-resolution ozone profiles critical for process studies and for satellite validation in the lower troposphere. However, the effectiveness of lidar validation by using single-station data is limited. Recently, NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly timeresolved (few minutes tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation. This article briefly describes the concept, stations, major specifications of the TOLNet instruments, and data archiving.

  11. Continuing education in ethical decision making using case studies from medical social work.

    Science.gov (United States)

    McCormick, Andrew J; Stowell-Weiss, Patti; Carson, Jennifer; Tebo, Gerald; Hanson, Inga; Quesada, Bianca

    2014-01-01

    Medical social workers have needs for training in ethics that is specific to dilemmas that arise while providing service to patients who are very ill, mentally compromised, or in a terminal condition. A social work department developed a continuing education training to educate social workers in bioethics related to determining decisional capacity and understanding standards of ethical decision making. Case studies are used to illustrate ethical conflicts and the role of social workers in resolving them. The benefits of case study training are discussed.

  12. The cost of continuity: A study of the performance of isogeometric finite elements using direct solvers

    KAUST Repository

    Collier, Nathaniel Oren

    2012-03-01

    We study the performance of direct solvers on linear systems of equations resulting from isogeometric analysis. The problem of choice is the canonical Laplace equation in three dimensions. From this study we conclude that for a fixed number of unknowns and polynomial degree of approximation, a higher degree of continuity k drastically increases the CPU time and RAM needed to solve the problem when using a direct solver. This paper presents numerical results detailing the phenomenon as well as a theoretical analysis that explains the underlying cause. © 2011 Elsevier B.V.

  13. Comparison of Fourier transform and continuous wavelet transform to study echo-planar imaging flow maps

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez G, A.; Bowtell, R.; Mansfield, P. [Area de Procesamiento Digital de Senales e Imagenes Biomedicas. Universidad Autonoma Metropolitana Iztapalapa. Mexico D.F. 09340 Mexico (Mexico)

    1998-12-31

    Velocity maps were studied combining Doyle and Mansfield method (1986) with each of the following transforms: Fourier, window Fourier and wavelet (Mexican hat). Continuous wavelet transform was compared against the two Fourier transform to determine which technique is best suited to study blood maps generated by Half Fourier Echo-Planar Imaging. Coefficient images were calculated and plots of the pixel intensity variation are presented. Finally, contour maps are shown to visualize the behavior of the blood flow in the cardiac chambers for the wavelet technique. (Author)

  14. STUDY OF DYNAMIC RECRYSTALLIZATION OF LOW CARBON STEEL IN THIN SLAB CONTINUOUS ROLLING PROCESS

    Institute of Scientific and Technical Information of China (English)

    X.K. Liang; X.J. Sun; Q.Y. Liu; H. Dong

    2006-01-01

    Combined with the technological characteristics of thin slab continuous rolling process (TSCR),dynamic recrystallization of an extremely coarse austenite of low carbon steel is studied by Thermecmaster-Z hot simulator. By the analysis of true stress-strain curves and the observation of microstructures at different deformation stages, the critical stress and critical strain are determined under different deformation conditions. The effect of Z parameter on dynamic recrystallization of coarse austenite is studied. The microstructure evolution in real production is also discussed.

  15. Disagreements in meta-analyses using outcomes measured on continuous or rating scales: observer agreement study

    DEFF Research Database (Denmark)

    Tendal, Britta; Higgins, Julian P T; Jüni, Peter

    2009-01-01

    OBJECTIVE: To study the inter-observer variation related to extraction of continuous and numerical rating scale data from trial reports for use in meta-analyses. DESIGN: Observer agreement study. DATA SOURCES: A random sample of 10 Cochrane reviews that presented a result as a standardised mean...... difference (SMD), the protocols for the reviews and the trial reports (n=45) were retrieved. DATA EXTRACTION: Five experienced methodologists and five PhD students independently extracted data from the trial reports for calculation of the first SMD result in each review. The observers did not have access...

  16. Continuous-wave 1.55 $\\mu$m diode-pumped surface emitting semiconductor laser for broadband multiplex spectroscopy

    CERN Document Server

    Jacquemet, M; Guelachvili, G; Picqué, N; Sagnes, I; Strassner, M; Symonds, C; Garnache, Arnaud; Guelachvili, Guy; Jacquemet, Mathieu; Picqu\\'{e}, Nathalie; Sagnes, Isabelle; Strassner, Martin; Symonds, Cl\\'{e}mentine

    2007-01-01

    A room temperature operating Vertical External Cavity Surface Emitting Laser is applied around 1550 nm to intracavity laser absorption spectroscopy analyzed by time-resolved Fourier transform interferometry. At an equivalent pathlength of 15 km, the high resolution spectrum of the semiconductor disk laser emission covers 17 nm simultaneously. A noise equivalent absorption coefficient at one second averaging equal to 1.5 10^{-10} cm^{-1}.Hz^{-1/2} per spectral element is reported for the 65 km longest path length employed.

  17. Sputter deposited bioceramic coatings: surface characterisation and initial protein adsorption studies using surface-MALDI-MS

    DEFF Research Database (Denmark)

    Boyd, A. R.; Burke, G. A.; Duffy, H.

    2011-01-01

    Protein adsorption onto calcium phosphate (Ca–P) bioceramics utilised in hard tissue implant applications has been highlighted as one of the key events that influences the subsequent biological response, in vivo. This work reports on the use of surface-matrix assisted laser desorption ionisation...... to a combination of growth factors and lipoproteins present in serum. From the data obtained here it is evident that surface-MALDI-MS has significant utility as a tool for studying the dynamic nature of protein adsorption onto the surfaces of bioceramic coatings, which most likely plays a significant role...

  18. Intensity-Modulated Continuous-Wave Lidar Measurements of Surface Reflectance and Implications for CO2 Column Measurements: Results from 2013 ASCENDS Airborne Campaign

    Science.gov (United States)

    Nehrir, A. R.; Browell, E. V.; Harrison, F. W.; Dobler, J. T.; Lin, B.; Ismail, S.; Kooi, S. A.; Obland, M. D.

    2013-12-01

    Improved knowledge of the Earth's surface reflectance in the 1.57-micron spectral band is of particular importance for accurate Integrated Path Differential Absorption (IPDA) measurements and modeling of IPDA CO2 column measurements as required by the Active Sensing of CO2 Emission of Nights Days and Seasons (ASCENDS) Decadal Survey space mission. The Earth's surface albedo in the near-infrared portion of the spectrum is extremely low for snow and ice and for water under high wind conditions, and this can lead to degraded signal to noise ratios of surface reflectances and of IPDA CO2 column retrievals, requiring increased integration periods. This paper discusses the magnitude and variability of the surface reflectance and corresponding column CO2 measurements over snow measured using an intensity-modulated continuous-wave (IM-CW) laser absorption spectrometer (LAS), namely the Exelis Multi-function Fiber Laser Lidar (MFLL), during the winter 2013 ASCENDS airborne campaign. This LAS system is currently being evaluated by NASA Langley as the ASCENDS space mission prototype system. The surface reflectance measurements over snow and ice as well as over water collected during the 2013 winter DC-8 flight campaign were calibrated using surface reflectance data obtained over well-established satellite radiometric calibration sites such as Railroad Valley, Nevada and over other homogeneous desert sites in California and Arizona that have been used for similar calibrations on past ASCENDS airborne campaigns. Two separate flights targeting differences in surface reflectances between fresh and aged snow were conducted over the U.S. Central Plains and Colorado Rockies, respectively. From these measurements, the nominal surface reflectance of fresh snow (less than 1-2 days old; ~ 0.01/sr at 1.57 microns) was found to be approximately half that of aged snow (3-4 days old; ~ 0.02/sr) which is believed to be a result of increased absorption due to the snow water content. The

  19. Development and evaluation of a PBL-based continuing education for clinical nurses: a pilot study.

    Science.gov (United States)

    Kim, Hee Soon; Hwang, Seon Young; Oh, Eui Geum; Lee, Jae Eun

    2006-12-01

    The purposes of this study were to develop a PBL program for continuing nurse education and to evaluate the program after its implementation. The PBL program was developed in the core cardio-pulmonary nursing concepts through a collaborative approach with a nursing school and a hospital. The PBL packages with simulation on ACLS were implemented to 40 clinical nurses. The entire PBL program consisted of six 3-hour weekly classes and was evaluated by the participants' subjective responses. Two PBL packages in cardio-pulmonary system including clinical cases and tutorial guidelines were developed. The 57.5% of the participants responded positively about the use of PBL as continuing nurse education in terms of self-motivated and cooperative learning, whereas 20.0% of the participants answered that the PBL method was not suitable for clinical nurses. Some modifications were suggested in grouping participants and program contents for PBL. The PBL method could be utilized to promote nurses' clinical competencies as well as self-learning abilities. Further research is needed in the implementation strategies of PBL-based continuing education in order to improve its effectiveness.

  20. Obstacles to continuity of care in young mental health service users’ pathways - an explorative study

    Directory of Open Access Journals (Sweden)

    Marian Ådnanes

    2013-08-01

    Full Text Available Background: Users of mental health services often move between different primary and specialised health and care services, depending on their current condition, and this often leads to fragmentation of care. The aim of this study was to map care pathways in the case of young adult mental health service users and to identify key obstacles to continuity of care. Method: Quarterly semi-structured interviews were performed with nine young adults with mental health difficulties, following their pathways in and out of different services in the course of a year. Results: Key obstacles to continuity of care included the mental health system's lack of access to treatment, lack of integration between different specialist services, lack of progress in care and inadequate coordination tools such as ‘Individual Plan’ and case conferences that did not prevent fragmented care pathways. Conclusions: Continuity of care should be more explicitly linked to aspirations for development and progress in the users' care pathways, and how service providers can cooperate with users to actually develop and make progress. Coordination tools such as case conferences and ‘individual plans’ should be upgraded to this end and utilised to the utmost. This may be the most effective way to counteract the system obstacles.

  1. Obstacles to continuity of care in young mental health service users’ pathways - an explorative study

    Directory of Open Access Journals (Sweden)

    Marian Ådnanes

    2013-08-01

    Full Text Available Background: Users of mental health services often move between different primary and specialised health and care services, depending on their current condition, and this often leads to fragmentation of care. The aim of this study was to map care pathways in the case of young adult mental health service users and to identify key obstacles to continuity of care.Method: Quarterly semi-structured interviews were performed with nine young adults with mental health difficulties, following their pathways in and out of different services in the course of a year.Results: Key obstacles to continuity of care included the mental health system's lack of access to treatment, lack of integration between different specialist services, lack of progress in care and inadequate coordination tools such as ‘Individual Plan’ and case conferences that did not prevent fragmented care pathways.Conclusions: Continuity of care should be more explicitly linked to aspirations for development and progress in the users' care pathways, and how service providers can cooperate with users to actually develop and make progress. Coordination tools such as case conferences and ‘individual plans’ should be upgraded to this end and utilised to the utmost. This may be the most effective way to counteract the system obstacles.

  2. How Visual Management for Continuous Improvement Might Guide and Affect Hospital Staff: A Case Study.

    Science.gov (United States)

    Ulhassan, Waqar; von Thiele Schwarz, Ulrica; Westerlund, Hugo; Sandahl, Christer; Thor, Johan

    2015-01-01

    Visual management (VM) tools such as whiteboards, often employed in Lean thinking applications, are intended to be helpful in improving work processes in different industries including health care. It remains unclear, however, how VM is actually applied in health care Lean interventions and how it might influence the clinical staff. We therefore examined how Lean-inspired VM using whiteboards for continuous improvement efforts related to the hospital staff's work and collaboration. Within a case study design, we combined semistructured interviews, nonparticipant observations, and photography on 2 cardiology wards. The fate of VM differed between the 2 wards; in one, it was well received by the staff and enhanced continuous improvement efforts, whereas in the other ward, it was not perceived to fit in the work flow or to make enough sense in order to be sustained. Visual management may enable the staff and managers to allow communication across time and facilitate teamwork by enabling the inclusion of team members who are not present simultaneously; however, its adoption and value seem contingent on finding a good fit with the local context. A combination of continuous improvement and VM may be helpful in keeping the staff engaged in the change process in the long run.

  3. Study of an ammonia-based wet scrubbing process in a continuous flow system

    Energy Technology Data Exchange (ETDEWEB)

    Resnik, Kevin P.; Pennline, Henry W.

    2013-03-01

    A continuous gas and liquid flow, regenerative scrubbing process for CO{sub 2} capture was demonstrated at the bench-scale level. An aqueous ammonia-based solution captures CO{sub 2} from simulated flue gas in an absorber and releases a nearly pure stream of CO{sub 2} in the regenerator. After the regeneration, the solution of ammonium compounds is recycled to the absorber. The design of a continuous flow unit was based on earlier exploratory results from a semi-batch reactor, where a CO{sub 2} and N{sub 2} simulated flue gas mixture flowed through a well-mixed batch of ammonia-based solution. During the semi-batch tests, the solution was cycled between absorption and regeneration steps to measure the carrying capacity of the solution at various initial ammonia concentrations and temperatures. Consequentially, a series of tests were conducted on the continuous unit to observe the effect of various parameters on CO{sub 2} removal efficiency and regenerator effectiveness within the flow system. The parameters that were studied included absorber temperature, regenerator temperature, initial NH{sub 3} concentration, simulated flue gas flow rate, liquid solvent inventory in the flow system, and height of the packed-bed absorber. From this testing and subsequent testing, ammonia losses from both the absorption and regeneration steps were quantified, and attempts were made to maintain steady state during operations. Implications of experimental results with respect to process design are discussed.

  4. Optimized Model Surfaces for Advanced Atomic Force Microscopy Studies of Surface Nanobubbles.

    Science.gov (United States)

    Song, Bo; Zhou, Yi; Schönherr, Holger

    2016-11-01

    The formation of self-assembled monolayers (SAMs) of binary mixtures of 16-mercaptohexadecanoic acid (MHDA) and 1-octadecanethiol (ODT) on ultraflat template-stripped gold (TSG) surfaces was systematically investigated to clarify the assembly behavior, composition, and degree of possible phase segregation in light of atomic force microscopy (AFM) studies of surface nanobubbles on these substrates. The data for SAMs on TSG were compared to those obtained by adsorption on rough evaporated gold, as reported in a previous study. Quartz crystal microbalance and surface plasmon resonance data acquired in situ on TSG indicate that similar to SAM formation on conventional evaporated gold substrates ODT and MHDA form monolayers and bilayers, respectively. The second layer on MHDA, whose formation is attributed to hydrogen bonding, can be easily removed by adequate rinsing with water. The favorable agreement of the grazing incidence reflection Fourier transform infrared (GIR FTIR) spectroscopy and contact angle data analyzed with the Israelachvili-Gee model suggests that the binary SAMs do not segregate laterally. This conclusion is fully validated by high-resolution friction force AFM observations down to a length scale of 8-10 nm, which is much smaller than the typical observed surface nanobubble radii. Finally, correspondingly functionalized TSG substrates are shown to be valuable supports for studying surface nanobubbles by AFM in water and for addressing the relation between surface functionality and nanobubble formation and properties.

  5. Continuous quality inspection in hard disc drive manufacturing: A case study

    Directory of Open Access Journals (Sweden)

    Yupa Lorkanchanakul

    2016-02-01

    Full Text Available This paper presents the continuous sampling plan CSP-100 that was developed from the continuous sampling plans CSP-1, CSP-4 and CSP-C. The objective of this paper is to apply the continuous sampling plan for the new CSP-100 plan proving a reduction in the delivery inspection time compared to the single lot sampling plan (SSP while maintaining the same or greater quality conformance. This CSP-100 was studied in Hard Disc Drive manufacturing. The parameters used in the CSP-100 plan are as follows; i (the number of consecutive conforming units, f (the sampling frequency of partial number in 100% inspected units and c (the acceptance number. CSP-100 computes four performance measures, Average Fraction Inspected (AFI, Average Outgoing Quality (AOQ, Lot Acceptance Rate (LAR and Defective Parts Per Million (DPPM. The advantage of this CSP-100 plan is not only to reduce the inspection time but also prove higher productivity numbers when compared with SSP. The verified results of using the CSP-100 plan proved a reduced inspection time of 6,722,702 minutes or 15% compared to SSP. CSP-100 also eliminates the work stations and transportation processes due to the inspection area and inspectors are no longer required. The Function Out of Box Audit (FOBA is introduced to monitor the CSP-100 performance. The FOBA audit results confirm that the CSP-100 maintains the same good quality level as the SSP. The excellent results of implementing the CSP-100 show a reduction in the inspection cost by 3,693,730.04 baht or 60.40% compared to SSP, as well as the additional cost savings by no longer needing to purchase a new tester; a savings of ~44 million baht. The CSP-100 plan also eliminates the issue of delayed delivery that is part of the SSP process. Moreover it is a better choice in inspecting the continuous quality process in Hard Disc Drive manufacturing.

  6. Studies of surfaces using optical second-harmonic generation

    Energy Technology Data Exchange (ETDEWEB)

    Tom, H.W.K.

    1984-04-01

    The experiments reported in this thesis demonstrate the use of second-harmonic generation (SHG) and sum-frequency generation (SFG) in reflection from surfaces to study various surface properties. The experiments firmly establish SHG as a viable new surface probe that complements existing surface probes in ultrahigh vacuum environments and is in many ways unique for studying interfaces between dense media. Surface structural symmetry can be revealed through the anisotropy in the SH signal from the surface as the sample is rotated about its normal. The form of this anisotropy is derived in theory and verified with an experiment on the Si(100) and (111) surfaces. The SHG and SFG signals from molecules adsorbed on noninteracting substrates have a direct relationship to the number, average orientation, and spectroscopic properties of the molecules. The SH intensity was used to measure the isotherm for adsorption of p-nitrobenzoic acid from ethanolic solution to fused silica. Experiments performed on a strongly-interacting well-characterized Rh(111) surface in ultrahigh vacuum establish the sensitivity of the SH probe in corroboration with other surface probes. For the first time, the SH coverage-dependence was fit by theory in a quantitative way for the case of O-atom adsorption. The sensitivity of SH to adsorption at different sites was established for CO on top- and bridge-sites. SHG was shown to be surface specific in that the SHG from alkali metal surfaces originates from the first two monolayers. SH sensitivity to the adsorption of catalytically-important hydrocarbons and to chemical processes such as benzene dehydrogenation was also demonstrated. 122 references, 27 figures, 2 tables.

  7. Microscopic Study of Surface Microtopographic Characteristics of Dental Implants.

    Science.gov (United States)

    Sezin, M; Croharé, L; Ibañez, J C

    2016-01-01

    To determine and compare the micro topographic characteristics of dental implants submitted to different surface treatments, using scanning electron microscopy (SEM). Implants were divided into 7 groups of 3 specimens each, according to the surface treatment used: group 1: Osseotite, BIOMET 3i; group 2: SLA surface, Institut Straumann AG; group 3: Oxalife surface, Tree-Oss implant; group 4: B&W implant surface; group 5: Q-implant surface; group 6: ML implant surface; group 7: RBM surface, Rosterdent implant. The surfaces were examined under SEM (Carl Zeiss FE-SEM-SIGMA). Image Proplus software was used to determine the number and mean diameter of pores per area unit (mm). The data obtained were analyzed with the Mann-Whitney test. A confocal laser microscope (LEXT-OLS4100 Olympus) was used to conduct the comparative study of surface roughness (Ra). Data were analyzed using Tukey's HSD test. The largest average pore diameter calculated in microns was found in group 5 (3.45 µm+/-1.91) while the smallest in group 7 (1.47µm+/-1.29). Significant differences were observed among each one of the groups studied (p<0.05). The largest number of pores/mm(2) was found in group 2 (229343) and the smallest number in group 4 (10937). Group 2 showed significant differences regarding the other groups (p<0.05). The greatest roughness (Ra) was observed in group 2 (0.975µm+/-0.115) and the smallest in group 4 (0.304µm+/-0.063). Group 2 was significantly different from the other groups (p<0.05). The micro topography observed in the different groups presented dissimilar and specific features, depending on the chemical treatment used for the surfaces..

  8. Microscopic Study of Surface Microtopographic Characteristics of Dental Implants

    Science.gov (United States)

    Sezin, M.; Croharé, L.; Ibañez, J.C.

    2016-01-01

    Objective: To determine and compare the micro topographic characteristics of dental implants submitted to different surface treatments, using scanning electron microscopy (SEM). Materials and Methods: Implants were divided into 7 groups of 3 specimens each, according to the surface treatment used: group 1: Osseotite, BIOMET 3i; group 2: SLA surface, Institut Straumann AG; group 3: Oxalife surface, Tree-Oss implant; group 4: B&W implant surface; group 5: Q-implant surface; group 6: ML implant surface; group 7: RBM surface, Rosterdent implant. The surfaces were examined under SEM (Carl Zeiss FE-SEM-SIGMA). Image Proplus software was used to determine the number and mean diameter of pores per area unit (mm). The data obtained were analyzed with the Mann-Whitney test. A confocal laser microscope (LEXT-OLS4100 Olympus) was used to conduct the comparative study of surface roughness (Ra). Data were analyzed using Tukey's HSD test. Results: The largest average pore diameter calculated in microns was found in group 5 (3.45 µm+/-1.91) while the smallest in group 7 (1.47µm+/-1.29). Significant differences were observed among each one of the groups studied (p<0.05). The largest number of pores/mm2 was found in group 2 (229343) and the smallest number in group 4 (10937). Group 2 showed significant differences regarding the other groups (p<0.05). The greatest roughness (Ra) was observed in group 2 (0.975µm+/-0.115) and the smallest in group 4 (0.304µm+/-0.063). Group 2 was significantly different from the other groups (p<0.05). Conclusion: The micro topography observed in the different groups presented dissimilar and specific features, depending on the chemical treatment used for the surfaces.. PMID:27335615

  9. Multi-objective Optimization of Continuous Drive Friction Welding Process Parameters Using Response Surface Methodology with Intelligent Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    P M AJITH; T MAFSAL HUSAIN; P SATHIYA; S ARAVINDAN

    2015-01-01

    The optimum friction welding (FW) parameters of duplex stainless steel (DSS) UNS S32205 joint was determined. The experiment was carried out as the central composite array of 30 experiments. The selected input parameters were friction pressure (F), upset pressure (U), speed (S) and burn-off length (B), and responses were hardness and ultimate tensile strength. To achieve the quality of the welded joint, the ultimate tensile strength and hardness were maximized, and response surface methodology (RSM) was applied to create separate regression equations of tensile strength and hardness. Intelligent optimization technique such as genetic algorithm was used to predict the Pareto optimal solutions. Depending upon the application, preferred suitable welding parameters were selected. It was inferred that the changing hardness and tensile strength of the friction welded joint inlfuenced the upset pressure, friction pressure and speed of rotation.

  10. Platelet adhesion studies on dipyridamole coated polyurethane surfaces

    Directory of Open Access Journals (Sweden)

    Aldenhoff Y. B.J.

    2003-06-01

    Full Text Available Surface modification of polyurethanes (PUs by covalent attachment of dipyridamole (Persantinregistered is known to reduce adherence of blood platelets upon exposure to human platelet rich plasma (PRP. This effect was investigated in further detail. First platelet adhesion under static conditions was studied with four different biomaterial surfaces: untreated PU, PU immobilised with conjugate molecule 1, PU immobilised with conjugate molecule 2, and PU immobilised with conjugate molecule 3. In PU immobilised with 1 dipyridamole is directly linked to the surface, in PU immobilised with 2 there is a short hydrophilic spacer chain in between the surface and the dipyridamole, while conjugate molecule 3 is merely the spacer chain. Scanning electron microscopy (SEM was used to characterise platelet adhesion from human PRP under static conditions, and fluorescence imaging microscopy was used to study platelet adhesion from whole blood under flow. SEM experiments encompassed both density measurements and analysis of the morphology of adherent platelets. In the static experiments the surface immobilised with 2 showed the lowest platelet adherence. No difference between the three modified surfaces emerged from the flow experiments. The surfaces were also incubated with washed blood platelets and labeled with Oregon-Green Annexin V. No capture of Oregon-Green Annexin V was seen, implying that the adhered platelets did not expose any phosphatidyl serine at their exteriour surface.

  11. Study of transient flow and particle transport in continuous steel caster molds: Part I. Fluid flow

    Science.gov (United States)

    Yuan, Quan; Thomas, Brian G.; Vanka, S. P.

    2004-08-01

    Unsteady three-dimensional flow in the mold region of the liquid pool during continuous casting of steel slabs has been computed using realistic geometries starting from the submerged inlet nozzle. Three large-eddy simulations (LES) have been validated with measurements and used to compare results between full-pool and symmetric half-pool domains and between a full-scale water model and actual behavior in a thin-slab steel caster. First, time-dependent turbulent flow in the submerged nozzle is computed. The time-dependent velocities exiting the nozzle ports are then used as inlet conditions for the flow in the liquid pool. Complex time-varying flow structures are observed in the simulation results, in spite of the nominally steady casting conditions. Flow in the mold region is seen to switch between a “double-roll” recirculation zone and a complex flow pattern with multiple vortices. The computed time-averaged flow pattern agrees well with measurements obtained by hot-wire anemometry and dye injection in full-scale water models. Full-pool simulations show asymmetries between the left and right sides of the flow, especially in the lower recirculation zone. These asymmetries, caused by interactions between two halves of the liquid pool, are not present in the half-pool simulation. This work also quantifies differences between flow in the water model and the corresponding steel caster. The top-surface liquid profile and fluctuations are predicted in both systems and agree favorably with measurements. The flow field in the water model is predicted to differ from that in the steel caster in having higher upward velocities in the lower-mold region and a more uniform top-surface liquid profile. A spectral analysis of the computed velocities shows characteristics similar to previous measurements. The flow results presented here are later used (in Part II of this article) to investigate the transport of inclusion particles.

  12. Theoretical study of fractal growth and stability on surface

    DEFF Research Database (Denmark)

    Dick, Veronika V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2009-01-01

    We perform a theoretical study of the fractal growing process on surface by using the deposition, diffusion, aggregation method. We present a detailed analysis of the post-growth processes occurring in a nanofractal on surface. For this study we developed a method which describes the internal...... dynamics of particles in a fractal and accounts for their diffusion and detachment. We demonstrate that these kinetic processes are responsible for the formation of the final shape of the islands on surface after the post-growth relaxation....

  13. Theoretical study of fractal growth and stability on surface

    DEFF Research Database (Denmark)

    Dick, Veronika V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2009-01-01

    We perform a theoretical study of the fractal growing process on surface by using the deposition, diffusion, aggregation method. We present a detailed analysis of the post-growth processes occurring in a nanofractal on surface. For this study we developed a method which describes the internal...... dynamics of particles in a fractal and accounts for their diffusion and detachment. We demonstrate that these kinetic processes are responsible for the formation of the final shape of the islands on surface after the post-growth relaxation....

  14. Experimental study of surface crystallization on integrated circuit chips

    Institute of Scientific and Technical Information of China (English)

    Zhang Xin; Liu Meng-Xin; Gao Yong; Wang Cai-Lin; Wang Zhi-Wei; Zhang Xian

    2006-01-01

    A surface crystallization phenomenon on bonding pads and wires of integrated circuit chip is reported in this paper. Through a lot of experiments, an unknown failure effect caused by mixed crystalline matter is revealed, whereas non-plasma fluorine contamination cannot cause the failure of bonding pads. By experiments combined with infrared spectroscopy analysis, the surface crystallization effect is studied. The conclusion of the study can provide the guidance for IC fabrication, modelling and analysis.

  15. Study of surface mud sediment in an urban environment

    Science.gov (United States)

    Seleznev, A.; Savastianova, A.; Yarmoshenko, I.

    2017-06-01

    Surface mud sediment is a media integrating pollution over space and time. Sampling of the mud sediment allows obtaining additional information about environmental state. The results of the study of surface mud sediment in Ekaterinburg city (Russia) are represented in the paper. Particle-size composition of the sediment is primarily represented by dust and fine sand. Study of the sediment allows ranking the territories over pollution degree with heavy metals, identifying technogenic and typomorphic geochemical associations of the elements in environmental compartments.

  16. Early Student Support for Process Studies of Surface Freshwater Dispersal

    Science.gov (United States)

    2016-06-24

    light field is varied to decay exponentially with depth. The spectra of tracer variance are computed for different growth rates and related to the...To) 06/24/2016 FINAL 12/01 /2012-03/31 /2016 4. TITLE AND SUBTITLE sa. CONTRACT NUMBER Early Student Support for Process Studies of Surface...ONRREPORT Early Student Support Process Studies of Surface Freshwater Dispersal June 24, 2016 Amala Mahadevan Woods Hole Oceanographic Institution

  17. A numerical study of three-dimensional surface tension driven convection with fre surface deformation

    Science.gov (United States)

    Hsieh, Kwang-Chung

    1992-01-01

    The steady three-dimensional thermocapillary motion with a deformable free surface is studied numerically in both normal and zero gravity environments. Flow configurations consist of a square cavity heated from the side. In the analysis, the free surface is allowed to deform and the grid distribution is adapted to the surface deformation. The divergence-free condition is satisfied by using a dual time-stepping approach in the numerical scheme. Convective flux derivatives are evaluated using a third-order accurate upwind-biased flux-split differencing technique. The numerical solutions at the midplane of the square cavity are compared with the results from two-dimensional calculations. In addition, numerial results for cases under zero and normal gravity conditions are compared. Significantly different flow structures and surface deformation have been observed. The comparison of calculated results will be compared with experimental data in the updated version of this paper.

  18. Meta-Analysis With a Continuous Covariate That Is Differentially Categorized Across Studies.

    Science.gov (United States)

    Perin, Jamie; Fischer Walker, Christa L; Black, Robert E; Aryee, Martin J

    2016-03-01

    We propose taking advantage of methodology for missing data to estimate relationships and adjust outcomes in a meta-analysis where a continuous covariate is differentially categorized across studies. The proposed method incorporates all available data in an implementation of the expectation-maximization algorithm. We use simulations to demonstrate that the proposed method eliminates bias that would arise by ignoring a covariate and generalizes the meta-analytical approach for incorporating covariates that are not uniformly categorized. The proposed method is illustrated in an application for estimating diarrhea incidence in children aged ≤59 months.

  19. Comparative study on performances of a continuously variable transmission used in two different powertrain architectures

    Science.gov (United States)

    Sibiceanu, A. R.; Ivan, F.; Nicolae, V.; Iorga, A.; Cioroianu, C.

    2017-08-01

    Given the importance of reducing carbon emissions from road transport, price and security of oil supply, hybrid electric vehicle can provide a viable alternative solution to conventional vehicles, equipped with thermal engines, which use fossil fuels. Based on the growing trends of new vehicles sales, which include hybrid and electric vehicles closely associated with their use in terms of harmful emissions, strict regulations are established. In this paper were created models of thermal and hybrid electric powertrains groups, using computer simulation program AVL Cruise, making a comparative study using petroleum fuels for continuously variable transmission. The results obtained highlights both fuel consumption as well as pollutant emissions.

  20. Continuously Phase-Modulated Standing Surface Acoustic Waves for Separation of Particles and Cells in Microfluidic Channels Containing Multiple Pressure Nodes

    CERN Document Server

    Lee, Junseok; Kang, Byungjun; Lee, Hyungsuk

    2016-01-01

    This paper describes continuously phase-modulated standing surface acoustic waves (CPM-SSAW) and its application for particle separation in multiple pressure nodes. A linear change of phase in CPM-SSAW applies a force to particles whose magnitude depends on their size and contrast factors. During continuous phase modulation, we demonstrate that particles with the target dimension are translated in the direction of moving pressure nodes, whereas smaller particles show oscillatory movements. The rate of phase modulation is optimized for separation of target particles from the relationship between mean particle velocity and period of oscillation. The developed technique is applied to separate particles of the target dimension from the particle mixture. Furthermore, we also demonstrate human keratinocyte cells can be separated in the cell and bead mixture. The separation technique is incorporated with a microfluidic channel spanning multiple pressure nodes, which is advantageous over separation in a single pressu...

  1. Continuously phase-modulated standing surface acoustic waves for separation of particles and cells in microfluidic channels containing multiple pressure nodes

    Science.gov (United States)

    Lee, Junseok; Rhyou, Chanryeol; Kang, Byungjun; Lee, Hyungsuk

    2017-04-01

    This paper describes continuously phase-modulated standing surface acoustic waves (CPM-SSAW) and its application for particle separation in multiple pressure nodes. A linear change of phase in CPM-SSAW applies a force to particles whose magnitude depends on their size and contrast factors. During continuous phase modulation, we demonstrate that particles with a target dimension are translated in the direction of moving pressure nodes, whereas smaller particles show oscillatory movements. The rate of phase modulation is optimized for separation of target particles from the relationship between mean particle velocity and period of oscillation. The developed technique is applied to separate particles of a target dimension from the particle mixture. Furthermore, we also demonstrate human keratinocyte cells can be separated in the cell and bead mixture. The separation technique is incorporated with a microfluidic channel spanning multiple pressure nodes, which is advantageous over separation in a single pressure node in terms of throughput.

  2. EMPLOYEES’ PERSPECTIVES ON CONTINUING MANAGEMENT EDUCATION (CME: A STUDY OF BPO INDUSTRY IN NOIDA

    Directory of Open Access Journals (Sweden)

    Dr. Kriti Priya,

    2015-10-01

    Full Text Available The paper focusses on the importance of Continuing Education in ‘Management’ area (Continuing Management Education (CME for working professionals of NOIDA (India based BPO companies. The study analyzes the role of three factors viz. ‘Institutional characteristics’, ‘Institutional support’, and ‘Features of CME programme’ in influencing the employees’ choices of education providers (institutes/colleges and CME programmes. The paper also analyzes the employees’ perspectives on the impact of CME on their Career Development (CD by considering two aspects of CD i.e. ‘Personal growth’ and ‘Professional growth’. A systematic survey of the employees of 11 randomly selected NOIDA based BPOs have been conducted for collecting primary data through structured questionnaires. The collected data has been analyzed using quantitative techniques. The findings of the study indicate that all the factors (Institutional characteristics, Institutional support, and Features of CME programme play an important role in the decision making of BPO employees regarding CME programmes. The results of the study also indicate that CME plays a significant role in the employees’ ‘Personal growth’ as well as ‘Professional growth’.

  3. An IB-LBM study of continuous cell sorting in deterministic lateral displacement arrays

    Science.gov (United States)

    Wei, Qiang; Xu, Yuan-Qing; Tang, Xiao-Ying; Tian, Fang-Bao

    2016-12-01

    The deterministic lateral displacement (DLD) is an important method used to sort particles and cells of different sizes. In this paper, the flexible cell sorting with the DLD method is studied by using a numerical model based on the immersed boundary-lattice Boltzmann method (IB-LBM). In this model, the fluid motion is solved by the LBM, and the cell membrane-fluid interaction is modeled with the LBM. The proposed model is validated by simulating the rigid particle sorted with the DLD method, and the results are found in good agreement with those measured in experiments. We first study the effect of flexibility on a single cell and multiple cells continuously going through a DLD device. It is found that the cell flexibility can significantly affect the cell path, which means the flexibility could have significant effects on the continuous cell sorting by the DLD method. The sorting characteristics of white blood cells and red blood cells are further studied by varying the spatial distribution of cylinder arrays and the initial cell-cell distance. The numerical results indicate that a well concentrated cell sorting can be obtained under a proper arrangement of cylinder arrays and a large enough initial cell-cell distance.

  4. Evaluation of Linear Alkylbenzene Sulfonate (LAS) behaviour in agricultural soil through laboratory continuous studies.

    Science.gov (United States)

    Oliver-Rodríguez, B; Zafra-Gómez, A; Reis, M S; Duarte, B P M; Verge, C; de Ferrer, J A; Pérez-Pascual, M; Vílchez, J L

    2015-07-01

    The behaviour of Linear Alkylbenzene Sulfonate (LAS) in agricultural soil is investigated in the laboratory using continuous-flow soil column studies in order to simultaneously analyze the three main underlying phenomena (adsorption/desorption, degradation and transport). The continuous-flow soil column experiments generated the breakthrough curves for each LAS homologue, C10, C11, C12 and C13, and by adding them up, for total LAS, from which the relevant retention, degradation and transport parameters could be estimated, after proposing adequate models. Several transport equations were considered, including the degradation of the sorbate in solution and its retention by soil, under equilibrium and non-equilibrium conditions between the sorbent and the sorbate. In general, the results obtained for the estimates of those parameters that were common to the various models studied (such as the isotherm slope, first order degradation rate coefficient and the hydrodynamic dispersion coefficient) were rather consistent, meaning that mass transfer limitations are not playing a major role in the experiments. These three parameters increase with the length of the LAS homologue chain. The study will provide the underlying conceptual framework and fundamental parameters to understand, simulate and predict the environmental behaviour of LAS compounds in agricultural soils.

  5. Surface Propensity of Atmospherically Relevant Amino Acids Studied by XPS.

    Science.gov (United States)

    Mocellin, Alexandra; Gomes, Anderson Herbert de Abreu; Araújo, Oscar Cardoso; de Brito, Arnaldo Naves; Bjorneholm, Olle

    2017-03-30

    Amino acids constitute an important fraction of the water-soluble organic nitrogen (WSON) compounds in aerosols and are involved in many processes in the atmosphere. In this work, we applied XPS to study aqueous solutions of four amino acids: glycine, alanine, valine and methionine, in their zwitterionic forms. We found that amino acids with hydrophilic side chains and smaller size, GLY and ALA, tend to stay in the bulk of the liquid, while the hydrophobic and bigger amino acids, VAL and MET, are found to concentrate more on the surface. We found experimental evidences that the amino acids have preferential orientation relative to the surface, with the hydrophobic side chain being closer to the surface than the hydrophilic carboxylate group. The observed amino acid surface propensity has implications in atmospheric science as the surface interaction play a central role in cloud droplet formation, and they should be considered in climate models.

  6. Deposition of latex colloids at rough mineral surfaces: an analogue study using nanopatterned surfaces.

    Science.gov (United States)

    Krishna Darbha, Gopala; Fischer, Cornelius; Michler, Alex; Luetzenkirchen, Johannes; Schäfer, Thorsten; Heberling, Frank; Schild, Dieter

    2012-04-24

    Deposition of latex colloids on a structured silicon surface was investigated. The surface with well-defined roughness and topography pattern served as an analogue for rough mineral surfaces with half-pores in the submicrometer size. The silicon topography consists of a regular pit pattern (pit diameter = 400 nm, pit spacing = 400 nm, pit depth = 100 nm). Effects of hydrodynamics and colloidal interactions in transport and deposition dynamics of a colloidal suspension were investigated in a parallel plate flow chamber. The experiments were conducted at pH ∼ 5.5 under both favorable and unfavorable adsorption conditions using carboxylate functionalized colloids to study the impact of surface topography on particle retention. Vertical scanning interferometry (VSI) was applied for both surface topography characterization and the quantification of colloidal retention over large fields of view. The influence of particle diameter variation (d = 0.3-2 μm) on retention of monodisperse as well as polydisperse suspensions was studied as a function of flow velocity. Despite electrostatically unfavorable conditions, at all flow velocities, an increased retention of colloids was observed at the rough surface compared to a smooth surface without surface pattern. The impact of surface roughness on retention was found to be more significant for smaller colloids (d = 0.3, 0.43 vs. 1, 2 μm). From smooth to rough surfaces, the deposition rate of 0.3 and 0.43 μm colloids increased by a factor of ∼2.7 compared to a factor of 1.2 or 1.8 for 1 and 2 μm colloids, respectively. For a substrate herein, with constant surface topography, the ratio between substrate roughness and radius of colloid, Rq/rc, determined the deposition efficiency. As Rq/rc increased, particle-substrate overall DLVO interaction energy decreased. Larger colloids (1 and 2 μm) beyond a critical velocity (7 × 10(-5) and 3 × 10(-6) m/s) (when drag force exceeds adhesion force) tend to detach from the surface

  7. Reactor models for a series of continuous stirred tank reactors with a gas-liquid-solid leaching system: Part I. Surface reaction control

    Science.gov (United States)

    Papangelakis, V. G.; Demopoulos, G. P.

    1992-12-01

    In this three-part series of articles, comprehensive three-phase steady-state hydrometallurgical reactor models of the continuous stirred tank reactor (CSTR) type are developed and applied to a commercial (pressure oxidation) process. The key features of the developed models are the coupling of both mass and heat balance equations, the description of the nonisothermal performance (autothermal) of a multistage continuous reactor, and the treatment of multimineral feed materials. The model considers only the oxidation reactions, because they mainly affect the thermal balance of the reactor. The stoichiometries and intrinsic kinetics of the heterogeneous leaching reactions, which are established via independent experiments, are the foundation of the developed model. A three-phase (g-l-s) reaction process might be controlled by either surface reaction control, i.e., the rate(s) of the heterogeneous leaching reaction(s), or by gas transfer control, i.e., the rate of transfer of the gaseous reactant into the liquid phase. In the present article (Part I), the case of surface reaction control is treated. The article addresses, in particular, the following topics: (1) it outlines the basic mass and heat balance equations which describe the performance of a multistage leaching reactor; (2) it presents a continuous function to describe the particle size distribution of the feed; and (3) it develops, on the basis of probability theory, number- and mass-particle size density functions which give the size distribution of particle populations reacting according to the surface reaction control-shrinking core model.

  8. Neural effects of mental fatigue caused by continuous attention load: a magnetoencephalography study.

    Science.gov (United States)

    Tanaka, Masaaki; Ishii, Akira; Watanabe, Yasuyoshi

    2014-05-02

    Mental fatigue can be defined as a psychobiological state caused by prolonged periods of demanding cognitive activity and manifests as a reduced efficiency in cognitive performance. Mental fatigue is one of the most significant causes of accidents in modern society. Therefore, understanding the neural mechanisms of mental fatigue is important. However, the neural mechanisms of mental fatigue are not fully understood. In this study, we investigated the neural activity that results from mental fatigue caused by a continuous attention load. We used magnetoencephalography (MEG) to evaluate the neural activities during the attention task. Ten healthy male volunteers participated in this study. They performed a continuous attention task lasting 10 min. Subjective ratings of mental fatigue, mental stress, boredom, and sleepiness were performed just after the task trial. MEG data were analyzed using narrow-band adaptive spatial filtering methods. An increase in the beta-frequency band (13-25 Hz) power in the right inferior and middle frontal gyri (Brodmann׳s areas 44 and 9 respectively) was caused by the mental fatigue. The increase in the beta-frequency band power in the right middle frontal gyrus was negatively associated with the self-reported level of mental stress and was positively associated with those of boredom and sleepiness. These results demonstrate that performing a continuous mental fatigue-inducing task causes changes in the activation of the prefrontal cortex, and manifests as an increased beta-frequency power in this brain area as well as sleepiness. Our results contribute to greater understanding of the neural mechanisms of mental fatigue.

  9. A Study of the Oscillation Marks' Characteristics of Continuously Cast Incoloy Alloy 825 Blooms

    Science.gov (United States)

    Saleem, Saud; Vynnycky, Michael; Fredriksson, Hasse

    2016-08-01

    A comprehensive experimental study of oscillation mark (OM) formation and its characteristics during the solidification of Incoloy alloy 825 in the continuous casting of blooms is investigated by plant trials and metallographic study. The experiments involved two heats with the same casting and mold conditions and sampling at different locations across the strand. The metallographic study combined macro/micro-examinations of OMs and segregation analysis of Cr, Mn, Mo, Ni, and Si by microprobe analysis. The results show that OMs have widely different characteristics, such as mark type, depth, segregation, and accompanying microstructure. Furthermore, the mark pitch can vary considerably even for the similar casting conditions, leading to different conditions for the marks' formation in relation to the mold's cyclic movement. Finally, a mechanism for the OM formation is discussed and proposed. Possible solutions for minimizing the observed defects by optimizing the mold conditions are suggested.

  10. Glass transition near the free surface studied by synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sikorski, M.

    2008-06-15

    A comprehensive picture of the glass transition near the liquid/vapor interface of the model organic glass former dibutyl phthalate is presented in this work. Several surface-sensitive techniques using x-ray synchrotron radiation were applied to investigate the static and dynamic aspects of the formation of the glassy state from the supercooled liquid. The amorphous nature of dibutyl phthalate close to the free surface was confirmed by grazing incidence X-ray diffraction studies. Results from X-ray reflectivity measurements indicate a uniform electron density distribution close to the interface excluding the possibility of surface freezing down to 175 K. Dynamics on sub-{mu}m length-scales at the surface was studied with coherent synchrotron radiation via x-ray photon correlation spectroscopy. From the analysis of the dispersion relation of the surface modes, viscoelastic properties of the dibutyl phthalate are deduced. The Kelvin-Voigt model of viscoelastic media was found to describe well the properties of the liquid/vapor interface below room temperature. The data show that the viscosity at the interface matches the values reported for bulk dibutyl phthalate. The scaled relaxation rate at the surface agrees with the bulk data above 210 K. Upon approaching the glass transition temperature the free surface was observed to relax considerably faster close to the liquid/vapor interface than in bulk. The concept of higher relaxation rate at the free surface is also supported by the results of the quasielastic nuclear forward scattering experiment, during which dynamics on molecular length scales around the calorimetric glass transition temperature is studied. The data were analyzed using mode-coupling theory of the glass transition and the model of the liquid(glass)/vapor interface, predicting inhomogeneous dynamics near the surface. The quasielastic nuclear forward scattering data can be explained when the molecular mobility is assumed to decrease with the increasing

  11. A Trial Study of Engineering Ethics Education for Continuing Engineering Education and Social Collaboration of Professional Engineers of Japan

    Science.gov (United States)

    Tanaka, Hidekazu; Uchida, Norio; Ito, Hiroshi; Haruta, Yoichi; Hiyagon, Hitoshi; Mizuno, Asao; Watanabe, Yoshihiro

    The ability of continuing study and working with high responsibility to the society are indispensable to all of professional engineers. The continuing engineering educations of professional engineers, such as initial professional development (IPD) and continuing professional development (CPD) are essential for the quality assurance of the profession. We propose a trial study of the engineering ethics education for the professional engineers' IPD and CPD activities. We discuss and demonstrate the effectiveness of the study with respect to the continuing engineering educations and the social collaboration.

  12. A prospective, longitudinal study to assess use of continuous and reactive low-pressure mattresses to reduce pressure ulcer incidence in a pediatric intensive care unit

    OpenAIRE

    García Molina, Pablo; Balaguer López, Evelin; Torra i Bou, Joan Enric; Álvarez Ordiales, Adán; Quesada Ramos, Cristina; Verdú Soriano, José

    2012-01-01

    Pressure between bony prominences and sleep surfaces, as well as pressure from the use of medical devices, put children admitted to pediatric intensive care units (PICUs) at risk of developing pressure ulcers (PUs). To assess the effect of two pediatric-specific, continuous and reactive low-pressure mattresses on the incidence of PUs, an observational, descriptive, prospective, longitudinal (2009–2011) study was conducted among PICU patients. The two pediatric mattresses — one for children we...

  13. Guar gum coupled microscale ZVI for in situ treatment of CAHs: continuous-flow column study.

    Science.gov (United States)

    Velimirovic, Milica; Simons, Queenie; Bastiaens, Leen

    2014-01-30

    A column study was performed under in situ conditions to evaluate to which extend the inactivation of the microscale zerovalent iron (mZVI) by guar gum occurs under continuous flow conditions. Five aquifer containing columns were set up under different conditions. Efficient removal of trichloroethene was observed for the column amended by mZVI. Stabilization of the mZVI with guar gum led to slightly reduced activity. More reduced reactivity was observed in the poisoned column containing guar gum stabilized mZVI. This confirms that soil microorganisms can degrade guar gum and that subsequent removal of the oligosaccharides by the groundwater flow (flushing effect) can reactivate the mZVI. After more than six months of continuous operation the columns were dismantled. DNA-based qPCR analysis revealed that mZVI does not significantly affect the bacterial community, while guar gum stabilized mZVI particles can even induce bacterial growth. Overall, this study suggests that the temporarily decreased mZVI reactivity due to guar gum, has a rather limited impact on the performance of in situ reactive zones. The presence of guar gum slightly reduced the reactivity of iron, but also slowed down the iron corrosion rate which prolongs the life time of reactive zone.

  14. Wireless non-invasive continuous respiratory monitoring with FMCW radar: a clinical validation study.

    Science.gov (United States)

    van Loon, K; Breteler, M J M; van Wolfwinkel, L; Rheineck Leyssius, A T; Kossen, S; Kalkman, C J; van Zaane, B; Peelen, L M

    2016-12-01

    Altered respiratory rate is one of the first symptoms of medical conditions that require timely intervention, e.g., sepsis or opioid-induced respiratory depression. To facilitate continuous respiratory rate monitoring on general hospital wards a contactless, non-invasive, prototype monitor was developed using frequency modulated continuous wave radar. We aimed to study whether radar can reliably measure respiratory rate in postoperative patients. In a diagnostic cross-sectional study patients were monitored with the radar and the reference monitor (pneumotachograph during mechanical ventilation and capnography during spontaneous breathing). Eight patients were included; yielding 796 min of observation time during mechanical ventilation and 521 min during spontaneous breathing. After elimination of movement artifacts the bias and 95 % limits of agreement for mechanical ventilation and spontaneous breathing were -0.12 (-1.76 to 1.51) and -0.59 (-5.82 to 4.63) breaths per minute respectively. The radar was able to accurately measure respiratory rate in mechanically ventilated patients, but the accuracy decreased during spontaneous breathing.

  15. Continuous blood pressure recordings simultaneously with functional brain imaging: studies of the glymphatic system

    Science.gov (United States)

    Zienkiewicz, Aleksandra; Huotari, Niko; Raitamaa, Lauri; Raatikainen, Ville; Ferdinando, Hany; Vihriälä, Erkki; Korhonen, Vesa; Myllylä, Teemu; Kiviniemi, Vesa

    2017-03-01

    The lymph system is responsible for cleaning the tissues of metabolic waste products, soluble proteins and other harmful fluids etc. Lymph flow in the body is driven by body movements and muscle contractions. Moreover, it is indirectly dependent on the cardiovascular system, where the heart beat and blood pressure maintain force of pressure in lymphatic channels. Over the last few years, studies revealed that the brain contains the so-called glymphatic system, which is the counterpart of the systemic lymphatic system in the brain. Similarly, the flow in the glymphatic system is assumed to be mostly driven by physiological pulsations such as cardiovascular pulses. Thus, continuous measurement of blood pressure and heart function simultaneously with functional brain imaging is of great interest, particularly in studies of the glymphatic system. We present our MRI compatible optics based sensing system for continuous blood pressure measurement and show our current results on the effects of blood pressure variations on cerebral brain dynamics, with a focus on the glymphatic system. Blood pressure was measured simultaneously with near-infrared spectroscopy (NIRS) combined with an ultrafast functional brain imaging (fMRI) sequence magnetic resonance encephalography (MREG, 3D brain 10 Hz sampling rate).

  16. Fuzzy Continuous Review Inventory Model using ABC Multi-Criteria Classification Approach: A Single Case Study

    Directory of Open Access Journals (Sweden)

    Meriastuti - Ginting

    2015-06-01

    Full Text Available Abstract. Inventory is considered as the most expensive, yet important,to any companies. It representsapproximately 50% of the total investment. Inventory cost has become one of the majorcontributorsto inefficiency, therefore it should be managed effectively. This study aims to propose an alternative inventory model, by using ABC multi-criteria classification approach to minimize total cost. By combining FANP (Fuzzy Analytical Network Process and TOPSIS (Technique of Order Preferences by Similarity to the Ideal Solution, the ABC multi-criteria classification approach identified 12 items of 69 inventory items as “outstanding important class” that contributed to 80% total inventory cost. This finding is then used as the basis to determine the proposed continuous review inventory model.This study found that by using fuzzy trapezoidal cost, the inventory turnover ratio can be increased, and inventory cost can be decreased by 78% for each item in “class A” inventory. Keywords:ABC multi-criteria classification, FANP-TOPSIS, continuous review inventory model lead-time demand distribution, trapezoidal fuzzy number

  17. Fuzzy Continuous Review Inventory Model using ABC Multi-Criteria Classification Approach: A Single Case Study

    Directory of Open Access Journals (Sweden)

    Meriastuti - Ginting

    2015-07-01

    Full Text Available Abstract. Inventory is considered as the most expensive, yet important,to any companies. It representsapproximately 50% of the total investment. Inventory cost has become one of the majorcontributorsto inefficiency, therefore it should be managed effectively. This study aims to propose an alternative inventory model,  by using ABC multi-criteria classification approach to minimize total cost. By combining FANP (Fuzzy Analytical Network Process and TOPSIS (Technique of Order Preferences by Similarity to the Ideal Solution, the ABC multi-criteria classification approach identified 12 items of 69 inventory items as “outstanding important class” that contributed to 80% total inventory cost. This finding  is then used as the basis to determine the proposed continuous review inventory model.This study found that by using fuzzy trapezoidal cost, the inventory  turnover ratio can be increased, and inventory cost can be decreased by 78% for each item in “class A” inventory.Keywords:ABC multi-criteria classification, FANP-TOPSIS, continuous review inventory model lead-time demand distribution, trapezoidal fuzzy number 

  18. Experimental study of combustion behavior during continuous hydrogen injection with an operating igniter

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Zhe, E-mail: zhe.liang@cnl.ca; Clouthier, Tony; Thomas, Bryan

    2016-03-15

    Highlights: • Combustion during continuous hydrogen release. • Periodical slow burning with a low release rate or weak turbulence. • Fast global burning with stratified hydrogen or strong turbulence. • Initiation of standing flame. - Abstract: Deliberate hydrogen ignition systems have been widely installed in many water cooled nuclear power plants to mitigate hydrogen risk in a loss-of-coolant accident. Experimental studies were performed at a large scale facility to simulate a post-accident containment scenario, where hydrogen is released into a volume (not closed) with an energized igniter. The test chamber had a volume of 60 m{sup 3}. The test parameters included hydrogen injection mass flow rate, injection elevation, igniter elevation, and level of turbulence in the chamber. Several dynamic combustion behaviors were observed. Under certain conditions, slow burning occurred periodically or locally without significant pressurization, and the hydrogen concentration could be maintained near the lean hydrogen flammability limit or a steady hydrogen distribution profile could be formed with a maximum hydrogen concentration less than 9 vol.%. Under other conditions, a global fast burn or a burn moving along the hydrogen dispersion pathway was observed and was followed by an immediate initiation of a standing flame. The study provided a better understanding of the dynamic combustion behavior induced by a deliberate igniter during a continuous hydrogen release. The data can be used for validation of combustion models used for hydrogen safety analysis.

  19. Study of H2S increasing in gas production of vapor continuous injection

    Energy Technology Data Exchange (ETDEWEB)

    Centeno, J. [PDVSA INTEVEP (Venezuela)

    2011-07-01

    In the heavy oil industry, thermal recovery methods are often used to enhance oil recovery, continuous vapor injection is one of them. In this method, water vapor is injected into the reservoir at high temperatures, affecting the geochemical system of the fluid reservoir. It has been noticed that the use of the continuous vapor injection method results in increased concentrations of H2S in gas production. Previous studies proved that H2S diffusion is affected by the H2S/CO2 ratio and this paper aimed at determining the influence of such ratios on the diffusion properties of acid gases. Experiments were conducted with three different H2S/CO2 ratios and heavy oil samples from Orinoco oil elt. Results showed that acid gas diffusion decreases when the H2S/CO2 ratio increases and that the diffusion of H2S is better with a high percentage of water. This study successfully assessed the variation of acid gas diffusion with different values of H2S/CO2 ratios and water percentages.

  20. Sputter deposited bioceramic coatings: surface characterisation and initial protein adsorption studies using surface-MALDI-MS.

    Science.gov (United States)

    Boyd, A R; Burke, G A; Duffy, H; Holmberg, M; O' Kane, C; Meenan, B J; Kingshott, P

    2011-01-01

    Protein adsorption onto calcium phosphate (Ca-P) bioceramics utilised in hard tissue implant applications has been highlighted as one of the key events that influences the subsequent biological response, in vivo. This work reports on the use of surface-matrix assisted laser desorption ionisation mass spectrometry (Surface-MALDI-MS) as a technique for the direct detection of foetal bovine serum (FBS) proteins adsorbed to hybrid calcium phosphate/titanium dioxide surfaces produced by a novel radio frequency (RF) magnetron sputtering method incorporating in situ annealing between 500°C and 700°C during deposition. XRD and XPS analysis indicated that the coatings produced at 700°C were hybrid in nature, with the presence of Ca-P and titanium dioxide clearly observed in the outer surface layer. In addition to this, the Ca/P ratio was seen to increase with increasing annealing temperature, with values of between 2.0 and 2.26 obtained for the 700°C samples. After exposure to FBS solution, surface-MALDI-MS indicated that there were significant differences in the protein patterns as shown by unique peaks detected at masses below 23.1 kDa for the different surfaces. These adsorbates were assigned to a combination of growth factors and lipoproteins present in serum. From the data obtained here it is evident that surface-MALDI-MS has significant utility as a tool for studying the dynamic nature of protein adsorption onto the surfaces of bioceramic coatings, which most likely plays a significant role in subsequent bioactivity of the materials.

  1. Experimental Study on Material Surface Modification of Tool Steel

    Institute of Scientific and Technical Information of China (English)

    沈丽如; 童洪辉; 王珂; 铁军; 孙爱萍

    2002-01-01

    This paper presents the surface temperature behavior of M42 high-speed tool steel samples during N+ implantation in an industrialized GLZ-100 metal-ion implantation machine. A detail study has been made on the parameters ofN+ implantation. Optimized technical parameters have been presented. The microhardness of the sample surface implanted under these parameters has been increased by a factor of 2.3, and the wear-resistance has been improved by about 5.4 times.The research on the mechanism of surface modification of M42 steel by nitrogen ion implantation has also been made.

  2. Study on Surface Free Energy of Thermochromic Wood

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Thermochromic wood is a kind of new functional materials. It is significant for thermochromic wood development to study surface free energy. Samples of Chinese white poplar were colored using thermochromic agent though the method of ultrasonic impregnation and its surface free energy was investigated in the experiment. The results showed that the surface free energy for untreated, black-red, orange-yellow and blue thermochromic wood was 40.25, 29.85, 28.30 and 21.05 mN/m, respectively. The FTIR results show...

  3. Experimental studies of surface plasmon polariton band gap effect

    DEFF Research Database (Denmark)

    Volkov, V. S.; Bozhevolnyi, S. I.; Leosson, K.

    2003-01-01

    Surface plasmon polaritons (SPPs) propagation at a gold film surface covered by periodic arrays of ~40-nm-high scatterers arranged in a triangular lattice of different periods containing straight line defects is studied using collection scanning near-field optical microscopy. The results reveal...... the dependence of the SPP band gap (SPPBG) effect manifested via the SPP reflection and guiding (along line defects) on the parameters of the surface structures (period, filling factor and lattice orientation). We find that the SPPBG effect is stronger along &ggr;K direction for all investigated periodic...

  4. Synthesis, surface characterization, and biointeraction studies of low-surface energy side-chain polyetherurethanes

    Science.gov (United States)

    Porter, Stephen Christopher

    1999-10-01

    New segmented polyetherurethanes (PEUs) with low surface energy hydrocarbon and fluorocarbon side-chains attached to the polymer hard segments were synthesized. The surface chemistry of solvent cast polymer films was studied using X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and dynamic contact angle (DCA) measurements. Increases in the overall density and length of the alkyl side-chains within the PEUs resulted in greater side-chain concentrations at the polymer surface. PEUs bearing long alkyl (> C10 ) and perfluorocarbon side-chains were found to posses surfaces with highly enriched side-chain concentrations relative to the bulk polymer. In PEUs with significant side-chain surface enrichment, the relatively polar hard segment blocks were shown to reside in high concentrations just below the side-chain enriched surface layer. Furthermore, DCA measurements demonstrated that the surface of the alkyl side-chain PEUs did not undergo significant rearrangement when placed into an aqueous environment, whereas the surface of a hard segment model polymer bearing C18 sidechains (PEU-C18-HS) did. Hydrogen bonding within the PEUs was examined using FTIR and was shown to be disrupted by the addition of side-chains; an effect dependent on the density but not on the length of the side-chains. Heteropolymer blends comprised of mixtures of high side-chain density and side-chain free PEUs were compared with homopolymers having the same overall side-chain concentration as the blends. Significantly more surface enrichment of side-chains was found in the heteropolymer blends whereas hydrogen bonding nearly the same as in the homopolymers. Adsorption of native and delipidized human serum albumin (HSA) from pure solution and blood plasma; the elutabilty of adsorbed HSA; and static platelet adhesion to plasma preadsorbed surfaces, were all examined on alkyl side-chain PEUs. Several polymers with high C18 side-chain densities displayed increased

  5. Exanthema after a stress Tc-99m sestamibi study: continue with a rest sestamibi study?

    DEFF Research Database (Denmark)

    Hesse, Birger; Vinberg, Niels; Mosbech, Holger

    2011-01-01

    Purpose:  A mild allergic reaction assumed to be caused by injection of Tc-99m sestamibi for a stress myocardial perfusion imaging (MPI) is presented. We want to discuss the risk involved in completing the MPI with another sestamibi injection, and the precautions and possible treatment in case of......, but anaphylactic reactions have been reported and may be life threatening. If repeated administration of the radio-pharmaceutical must be given, the prophylactic and therapeutic interventions should follow general international guidelines for allergic reactions........ After prophylactic treatment with antihistamine and corticosteroid, an uneventful rest MPI was performed. Discussion and conclusion:  International recommendations or guidelines related to treatment of AEs after nuclear medicine studies do not exist. Serious AEs in nuclear medicine are very rare...

  6. Sonde data of continuous surface water flow-through system for the West Florida Shelf: USGS Cruise 11BHM01

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing...

  7. Sonde data of continuous surface water flow-through system for the West Florida Shelf: USGS Cruise 11BHM02

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing...

  8. Sonde data of continuous surface water flow-through system for the West Florida Shelf: USGS Cruise 11CEV02

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing...

  9. Sonde data of continuous surface water flow-through system for the West Florida Shelf: USGS Cruise 11BHM04

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing...

  10. Sonde data of continuous surface water flow-through system for the West Florida Shelf: USGS Cruise 11BHM01

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing...

  11. Sonde data of continuous surface water flow-through system for the West Florida Shelf: USGS Cruise 11BHM03

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing...

  12. Sonde data of continuous surface water flow-through system for the West Florida Shelf: USGS Cruise 11BHM03

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing...

  13. Sonde data of continuous surface water flow-through system for the West Florida Shelf: USGS Cruise 11CEV02

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing...

  14. Sonde data of continuous surface water flow-through system for the West Florida Shelf: USGS Cruise 11BHM02

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing...

  15. Sonde data of continuous surface water flow-through system for the West Florida Shelf: USGS Cruise 11BHM04

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing...

  16. Continuity theory

    CERN Document Server

    Nel, Louis

    2016-01-01

    This book presents a detailed, self-contained theory of continuous mappings. It is mainly addressed to students who have already studied these mappings in the setting of metric spaces, as well as multidimensional differential calculus. The needed background facts about sets, metric spaces and linear algebra are developed in detail, so as to provide a seamless transition between students' previous studies and new material. In view of its many novel features, this book will be of interest also to mature readers who have studied continuous mappings from the subject's classical texts and wish to become acquainted with a new approach. The theory of continuous mappings serves as infrastructure for more specialized mathematical theories like differential equations, integral equations, operator theory, dynamical systems, global analysis, topological groups, topological rings and many more. In light of the centrality of the topic, a book of this kind fits a variety of applications, especially those that contribute to ...

  17. Are physical activity studies in Hispanics meeting reporting guidelines for continuous monitoring technology? A systematic review.

    Science.gov (United States)

    Layne, Charles S; Parker, Nathan H; Soltero, Erica G; Rosales Chavez, José; O'Connor, Daniel P; Gallagher, Martina R; Lee, Rebecca E

    2015-09-18

    Continuous monitoring technologies such as accelerometers and pedometers are the gold standard for physical activity (PA) measurement. However, inconsistencies in use, analysis, and reporting limit the understanding of dose-response relationships involving PA and the ability to make comparisons across studies and population subgroups. These issues are particularly detrimental to the study of PA across different ethnicities with different PA habits. This systematic review examined the inclusion of published guidelines involving data collection, processing, and reporting among articles using accelerometers or pedometers in Hispanic or Latino populations. English (PubMed; EbscoHost) and Spanish (SCIELO; Biblioteca Virtual en Salud) articles published between 2000 and 2013 using accelerometers or pedometers to measure PA among Hispanics or Latinos were identified through systematic literature searches. Of the 253 abstracts which were initially reviewed, 57 met eligibility criteria (44 accelerometer, 13 pedometer). Articles were coded and reviewed to evaluate compliance with recommended guidelines (N = 20), and the percentage of accelerometer and pedometer articles following each guideline were computed and reported. On average, 57.1 % of accelerometer and 62.2 % of pedometer articles reported each recommended guideline for data collection. Device manufacturer and model were reported most frequently, and provision of instructions for device wear in Spanish was reported least frequently. On average, 29.6 % of accelerometer articles reported each guideline for data processing. Definitions of an acceptable day for inclusion in analyses were reported most frequently, and definitions of an acceptable hour for inclusion in analyses were reported least frequently. On average, 18.8 % of accelerometer and 85.7 % of pedometer articles included each guideline for data reporting. Accelerometer articles most frequently included average number of valid days and least frequently

  18. Comparative study of gas-analyzing systems designed for continuous monitoring of TPP emissions

    Science.gov (United States)

    Kondrat'eva, O. E.; Roslyakov, P. V.

    2017-06-01

    Determining the composition of combustion products is important in terms of both control of emissions into the atmosphere from thermal power plants and optimization of fuel combustion processes in electric power plants. For this purpose, the concentration of oxygen, carbon monoxide, nitrogen, and sulfur oxides in flue gases is monitored; in case of solid fuel combustion, fly ash concentration is monitored as well. According to the new nature conservation law in Russia, all large TPPs shall be equipped with continuous emission monitoring and measurement systems (CEMMS) into the atmosphere. In order to ensure the continuous monitoring of pollutant emissions, direct round-the-clock measurements are conducted with the use of either domestically produced or imported gas analyzers and analysis systems, the operation of which is based on various physicochemical methods and which can be generally used when introducing CEMMS. Depending on the type and purposes of measurement, various kinds of instruments having different features may be used. This article represents a comparative study of gas-analysis systems for measuring the content of polluting substances in exhaust gases based on various physical and physicochemical analysis methods. It lists basic characteristics of the methods commonly applied in the area of gas analysis. It is proven that, considering the necessity of the long-term, continuous operation of gas analyzers for monitoring and measurement of pollutant emissions into the atmosphere, as well as the requirements for reliability and independence from aggressive components and temperature of the gas flow, it is preferable to use optical gas analyzers for the aforementioned purposes. In order to reduce the costs of equipment comprising a CEMMS at a TPP and optimize the combustion processes, electrochemical and thermomagnetic gas analyzers may also be used.

  19. Illusory vowels resulting from perceptual continuity: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Heinrich, Antje; Carlyon, Robert P; Davis, Matthew H; Johnsrude, Ingrid S

    2008-10-01

    We used functional magnetic resonance imaging to study the neural processing of vowels whose perception depends on the continuity illusion. Participants heard sequences of two-formant vowels under a number of listening conditions. In the "vowel conditions," both formants were always present simultaneously and the stimuli were perceived as speech-like. Contrasted with a range of nonspeech sounds, these vowels elicited activity in the posterior middle temporal gyrus (MTG) and superior temporal sulcus (STS). When the two formants alternated in time, the "speech-likeness" of the sounds was reduced. It could be partially restored by filling the silent gaps in each formant with bands of noise (the "Illusion" condition) because the noise induced an illusion of continuity in each formant region, causing the two formants to be perceived as simultaneous. However, this manipulation was only effective at low formant-to-noise ratios (FNRs). When the FNR was increased, the illusion broke down (the "illusion-break" condition). Activation in vowel-sensitive regions of the MTG was greater in the illusion than in the illusion-break condition, consistent with the perception of Illusion stimuli as vowels. Activity in Heschl's gyri (HG), the approximate location of the primary auditory cortex, showed the opposite pattern, and may depend instead on the number of perceptual onsets in a sound. Our results demonstrate that speech-sensitive regions of the MTG are sensitive not to the physical characteristics of the stimulus but to the perception of the stimulus as speech, and also provide an anatomically distinct, objective physiological correlate of the continuity illusion in human listeners.

  20. Wetting and evaporation studies on molecularly modified surfaces

    OpenAIRE

    Soolaman, Dinah Michele

    2007-01-01

    Wetting and evaporation of liquid microdroplets on solid surfaces are ubiquitous in nature. Two of the many important factors that influence how a droplet wets and “escapes”, are the chemical composition and roughness of the solid surface. In order to gain a better understanding of these processes as a whole, a systematic study on the factors that influence wetting/evaporation behaviour, including the liquid’s composition, the liquid-solid interface, and the substrate morphology has been carr...

  1. Experimental Study of a Membrane Antenna Surface Adaptive Control System

    Science.gov (United States)

    Fang, H.; Quijano, U.; Bach, V.; Hill, J.; Wang, K. W.

    2011-01-01

    Due to their ultra lightweight and high packaging efficiency, membrane reflectors are getting more and more attentions for mission architectures that need extremely large inspace deployable antennas. However how to maintain the surface shape of a membrane reflector to the instrument precision requirements is a very challenging problem. This experimental study investigated using PVDF membrane piezoelectric material as actuators to control the surface figures of membrane reflectors. The feasibility of this approach is demonstrated by several sets of test results.

  2. Positron studies of surfaces, structure and electronic properties of nanocrystals

    OpenAIRE

    Eijt, S. W. H.; Barbiellini, B.; Houtepen, A.J.; Vanmaekelbergh, D.; Mijnarends, P. E.; Bansil, A.

    2007-01-01

    A brief review is given of recent positron studies of metal and semiconductor nanocrystals. The prospects offered by positron annihilation as a sensitive method to access nanocrystal (NC) properties are described and compared with other experimental methods. The tunability of the electronic structure of nanocrystals underlies their great potential for application in many areas. Owing to their large surface-to-volume ratio, the surfaces and interfaces of NCs play a crucial role in determining ...

  3. Study on Obstacles to Continuous Cropping of Vegetables and Soil Remediation Technology

    Institute of Scientific and Technical Information of China (English)

    Pingsheng FAN; Gang CHEN; Deli XU; Weimin FENG; Yuyu LU; Anqin GUAN

    2016-01-01

    Firstly,this paper analyzes the cause of obstacles to continuous cropping of vegetables,and then introduces the soil ecological remediation technology used for overcoming obstacles to continuous cropping of vegetables. Finally,this paper analyzes the effect of applying soil ecological remediation technology in overcoming obstacles to continuous cropping of vegetables.

  4. PIV and LIF study of slot continuous jet at low Reynolds number

    Directory of Open Access Journals (Sweden)

    Broučková Zuzana

    2016-01-01

    Full Text Available This study deals with a continuous jet issuing from a small narrow slot with a width of 0.36 mm. The experimental arrangement is based on the piezoelectric synthetic jet actuator studied previously for easy comparisons. The working fluid is water at room temperature. The experiments were performed using methods of particle image velocimetry (PIV and flow visualization (laser induced fluorescence, LIF. The time-mean volume flux through the exit nozzle was quantified using precise scales. The mean velocity and the Reynolds number were evaluated as Um = 0.12 m/s and Re = 90, respectively. The results of LIF and PIV techniques revealed the three-dimensional character of the flow field, namely the saddle-shape velocity profiles. This behavior is typical for steady jets from a rectangular nozzle. The obtained results were compared with previous measurements of the synthetic jet issuing from the same cavity and the slot nozzle.

  5. Feasibility and design study of continuously variable capacity refrigeration plant. A demonstration at Safeway plc

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    This report concerns a feasibility and design study carried out on a new type of high efficiency refrigeration system for use in supermarkets. The study compared the performance of Margaux Continuously Variable Capacity (CVC) refrigeration equipment with conventional supermarket plant. The tests were carried out at a Presto store in Stanley near Newcastle-upon-Tyne from August 1988 to February 1989. They involved assessment of systems for both chilled food (HT) and frozen food (LT). Significant energy savings were achieved by the CVC equipment. The HT system reduced energy consumption by 56% compared with conventional plant. Measured LT savings were only 13%, although adjustments made for monitoring problems and improved temperature control indicate savings of around 30%. (author)

  6. Organisational performance and business continuity management: a theoretical perspective and a case study.

    Science.gov (United States)

    Sawalha, Ihab Hanna Salman

    2013-01-01

    This paper seeks to extend the research relating to the strategic view of business continuity management (BCM) to the context of organisational performance (OP). It discusses potential performance consequences resulting from applying BCM aspects/elements within an organisation. The paper contributes to the understanding of the role of BCM in OP by discussing how deployment of BCM key aspects/elements can improve OP. Two main issues are discussed: first, background to performance and the elements of OP; and secondly, the role of BCM in achieving optimised OP. These issues are significant, as they go further than the extant literature relating to the significance of BCM and its potential influence on OP. The study focuses on Jordanian banks as a case study and as a way of illustrating how BCM helps improve OP for those organisations facing performance shortcomings or difficulties.

  7. A phase I and pharmacokinetic study with 21-day continuous infusion of epirubicin.

    Science.gov (United States)

    de Vries, E G; Greidanus, J; Mulder, N H; Nieweg, M B; Postmus, P E; Schipper, D L; Sleijfer, D T; Uges, D R; Willemse, P H

    1987-09-01

    A phase I study with continuous administration of epirubicin for 21 days using a venous access port and a portable pump was performed. The first dose step was 2 mg/m2/d for 21 days. Interval between courses was 3 weeks. Dose increment per step was 1 mg/m2/d. Twenty-two patients entered the study and received a total of 58 courses with a median of two (range, one to nine). Up to 5 mg/m2/d no toxicity (according to World Health Organization [WHO] criteria) occurred. At 6 mg/m2/d (six pts), one patient had leukopenia grade 3. Two others had some hair loss. At 7 mg/m2/d (four patients), all patients developed mucositis (two grade 3). Three patients had bone marrow depression (one grade 3 anemia, one grade 4 leukocytopenia), and one patient developed the hand-foot syndrome. No other toxicity occurred in the patients. One patient obtained a partial response (18 weeks), ten had stable disease (12 to 54 weeks), seven had progressive disease, and four were not evaluable for response. One patient developed cellulitis around the port, responding to antibiotic treatment; one patient developed a vena cava superior syndrome that resolved with urokinase and removal of the access port. No septicemia occurred. Pharmacokinetic studies were performed by high-performance liquid chromatography (HPLC) with fluorometric detection. Plasma steady state was reached after 57 hours. During steady state there was a linear relationship between epirubicin dose administered and epirubicin level in plasma (r = .58, P less than .05), whole blood (r = .75, P less than .005), and in leukocytes (r = .68, P less than .05). The area under the curve in leukocytes was higher with continuous infusion of 6 mg/m2 for 21 days compared with bolus injection of 80 mg/m2. This method of continuous infusion with epirubicin may be a way to increase intracellular drug-uptake as expressed by intracellular area under curve (AUC). We recommend 6 mg/m2/d for 3 weeks for evaluation of antitumor efficacy in phase II

  8. A Process Evaluation of Project Developmental Continuity. Interim Report II, Part A: Program Case Studies. Volume I.

    Science.gov (United States)

    Spencer, Lynn, Ed.

    These 8 case studies are part of a series of documents on the evaluation of Project Developmental Continuity (PDC), a Head Start demonstration program aimed at providing educational and developmental continuity between children's Head Start and primary school experiences. Each case study reviews the planning year at a PDC demonstration site in one…

  9. A Process Evaluation of Project Developmental Continuity. Interim Report II, Part A: Program Case Studies. Volume 2.

    Science.gov (United States)

    Spencer, Lynn, Ed.

    These 7 case studies are part of a series of documents on the evaluation of Project Developmental Continuity (PDC), a Head Start demonstration program aimed at providing educational and developmental continuity between children's Head Start and primary school experiences. Each case study reviews the planning year at a PDC demonstration site in one…

  10. A Monte Carlo study of time-aggregation in continuous-time and discrete-time parametric hazard models.

    NARCIS (Netherlands)

    Hofstede, ter F.; Wedel, M.

    1998-01-01

    This study investigates the effects of time aggregation in discrete and continuous-time hazard models. A Monte Carlo study is conducted in which data are generated according to various continuous and discrete-time processes, and aggregated into daily, weekly and monthly intervals. These data are

  11. A continuous nonlinear model approach to study the behavior of large signal DC to DC converters

    Science.gov (United States)

    Guinjoan, Francisco

    The study of signal switching DC-DC converters behavior is addressed. Given the fact that the linear methods cannot be used in this case, a nonlinear model was developed. The power stage nonlinear continuous model, which can be applied in both conduction modes (continuous and discontinuous), is obtained from the partition of the characteristic state vector variables in two subsets. This method is applied to the elementary switching cells (buck, boost, and buck-boost) and Cuk converter. It is oriented to the fast numerical simulation by means of general purpose simulation programs. Different results from numerical simulations, confirming the accuracy of the method used, either in an open loop or in a closed loop, are obtained, provided the validity of its domain is respected. The nonlinear model linearization made it possible to obtain equivalent transmittances for the DC-DC converters. Its application to a boost converter operating in the discontinuous condition mode at variable frequency rate enables the comparison of the obtained results with other existing methods and equivalence between the two of them to be easily established. The revision of the initial hypothesis leads to the establishment of a small signal model valid in the high frequency domain and to the results obtained being derived in a more systematic way. A model for switching DC-DC converters is given. Its validity is established, whatever its order and conduction modes, either in an open loop or a closed loop.

  12. Original position statistic distribution analysis study of low alloy steel continuous casting billet

    Institute of Scientific and Technical Information of China (English)

    WANG; Haizhou; ZHAO; Pei; CHEN; Jiwen; LI; Meiling; YANG; Z

    2005-01-01

    The homogeneity of low alloy steels continuous casting billet obtained under different technological conditions has been investigated by original position statistic distribution analysis technique. On the basis of systematic analysis of ten thousands primary optical signals at the corresponding original positions, the quantitative statistic distribution information of each element was obtained. The biggest degrees of segregation of low alloy steel continuous casting billet were calculated accurately according to the quantitative distribution maps of the contents. It was suggested that the weight ratio in a certain content range was used to judge the homogeneity of the materials, and the two models -- the total weight ratio of contents (the degree of statistic homogeneity, H) within the permissive content range (C0±R) and the median value confidence extension ratio (the degree of statistic segregation, S) at 95% of confidence limit of weight ratio -- were put forward. The two models reflect the composition and state distribution regularity of the metal materials in a large region. The difference between the sample with high columnar crystal and the sample with high equiaxed crystal has been studied by using the two models.

  13. Strategic planning as a focus for continuous improvement. A case study

    Science.gov (United States)

    Oneill, John W.; Gordon-Winkler, Lyn

    What do most of the successful people and organizations in our world have in common? Instead of worrying about the future, they work to create it. They have a plan, or a vision of what they want to accomplish and they focus their efforts on success. Strategic planning has been described as a disciplined, ongoing process to produce fundamental decisions and actions that shape what an organization is, what it does, and how it will respond to a changing environment. This case study discussion will evaluate the relationship between strategic planning and Total Quality Management (TQM), or continuous improvement, through the experience of the NASA Johnson Space Center in developing a strategy for the future. That experience clearly illustrates the value of strategic planning in setting the framework and establishing the overall thrust of continuous improvement initiatives. Equally significant, the fundamentals of a quality culture such as strong customer and supplier partnerships, participative involvement, open communications, and ownership were essential in overcoming the challenges inherent in the planning process. A reinforced management commitment to the quality culture was a clear, long-term benefit.

  14. Study on shear strengthening of RC continuous T-beams using different layers of CFRP strips

    Energy Technology Data Exchange (ETDEWEB)

    Alferjani, M. B. S.; Samad, A. A. Abdul; Mohamad, Noridah [Faculty of Civil and Environmental Engineering, Universiti Tun Hussein Onn Malaysia, Batu Pahat (Malaysia); Elrawaff, Blkasem S.; Elzaroug, Omer [Faculty of Civil Engineering Omar Al Mukhtar University, Bayda, Libya, Africa (Libya)

    2015-05-15

    Carbon fiber reinforced polymer (CFRP) laminates are externally bonded to reinforced concrete (RC) members to provide additional strength such as flexural, shear, etc. However, this paper presents the results of an experimental investigation for enhancing the shear capacity of reinforced concrete (RC) continuous T- beams using different layers of CFRP wrapping schemes. A total of three concrete beams were tested and various sheet configurations and layouts were studied to determine their effects on ultimate shear strength and shear capacity of the beams. One beam was kept as control beams, while other beams were strengthened with externally bonded CFRP strips with three side bonding and one or two layers of CFRP strips. From the test results, it was found that all schemes were found to be effective in enhancing the shear strength of RC beams. It was observed that the strength increases with the number of sheet layers provided the most effective strengthening for RC continuous T- beam. Beam strengthened using this scheme showed 23.21% increase in shear capacity as compared to the control beam. Two prediction models available in literature were used for computing the contribution of CFRP strips and compared with the experimental results.

  15. Experimental study on the sound absorption characteristics of continuously graded phononic crystals

    Directory of Open Access Journals (Sweden)

    X. H. Zhang

    2016-10-01

    Full Text Available Novel three-dimensional (3D continuously graded phononic crystals (CGPCs have been designed, and fabricated by 3D printing. Each of the CGPCs is an entity instead of a combination of several other samples, and the porosity distribution of the CGPC along the incident direction is nearly linear. The sound absorption characteristics of CGPCs were experimentally investigated and compared with those of uniform phononic crystals (UPCs and discretely stepped phononic crystals (DSPCs. Experimental results show that CGPCs demonstrate excellent sound absorption performance because of their continuously graded structures. CGPCs have higher sound absorption coefficients in the large frequency range and more sound absorption coefficient peaks in a specific frequency range than UPCs and DSPCs. In particular, the sound absorption coefficients of the CGPC with a porosity of 0.6 and thickness of 30 mm are higher than 0.56 when the frequency is 1350–6300 Hz and are all higher than 0.2 in the studied frequency range (1000–6300 Hz. CGPCs are expected to have potential application in noise control, especially in the broad frequency and low-frequency ranges.

  16. Study on shear strengthening of RC continuous T-beams using different layers of CFRP strips

    Science.gov (United States)

    Alferjani, M. B. S.; Samad, A. A. Abdul; Elrawaff, Blkasem S.; Elzaroug, Omer; Mohamad, Noridah

    2015-05-01

    Carbon fiber reinforced polymer (CFRP) laminates are externally bonded to reinforced concrete (RC) members to provide additional strength such as flexural, shear, etc. However, this paper presents the results of an experimental investigation for enhancing the shear capacity of reinforced concrete (RC) continuous T- beams using different layers of CFRP wrapping schemes. A total of three concrete beams were tested and various sheet configurations and layouts were studied to determine their effects on ultimate shear strength and shear capacity of the beams. One beam was kept as control beams, while other beams were strengthened with externally bonded CFRP strips with three side bonding and one or two layers of CFRP strips. From the test results, it was found that all schemes were found to be effective in enhancing the shear strength of RC beams. It was observed that the strength increases with the number of sheet layers provided the most effective strengthening for RC continuous T- beam. Beam strengthened using this scheme showed 23.21% increase in shear capacity as compared to the control beam. Two prediction models available in literature were used for computing the contribution of CFRP strips and compared with the experimental results.

  17. Kinetic study of austenite formation during continuous heating of unalloyed ductile iron

    Institute of Scientific and Technical Information of China (English)

    Octavio Vzquez-Gmez; Jos Antonio Barrera-Godnez; Hctor Javier Vergara-Hernndez

    2015-01-01

    The austenite formation kinetics in unalloyed cast ductile iron was studied on the basis of dilatometry measurements, and Avrami’s equation was used to estimate the material’s kinetic parameters. A continuous heating transformation diagram was constructed us-ing heating rates in the range of 0.06 to 0.83°C⋅s−1. As the heating rate was augmented, the critical temperatures, c1A and Aα, as well as the intercritical range, which was evaluated as the difference between the critical temperatures, α c1Δ T =A −A , increased. At a low heating rate, the kinetics of austenite formation was slow as a consequence of the iron’s silicon content. The effect of heating rate on k and n, the kinetic parameters of Avrami’s equation, was also determined. Parameter n, which is associated with nucleation sites and growth geometry, de-creased with an increase in heating rate. In addition, parameter k increased with the increase of heating rate, suggesting that the nucleation and growth rates are carbon-and silicon-diffusion controlled during austenite formation under continuous heating.

  18. Surface properties of hard protective coatings studied by optical techniques

    Science.gov (United States)

    Jaglarz, Janusz; Wolska, N.; Mitura, K.; Duraj, R.; Marszalek, K. W.; El Kouari, Y.

    2016-06-01

    The paper describes optical study of SiC, C and NiC layers deposited on Si substrates by double beam ion sputtering (DBIS) method. The following optical methods: ellipsometry, bidirectional reflection distribution function (BRDF) and total integrated scattering (TIS) studies have been applied. The obtained results allowed us to determine the refractive indices, extinction coefficients and the roughness parameters of DBIS films. Also surface profiles of optical constants determined from scanning ellipsometric measurements have been presented. The power spectral density functions (PSD) of surface roughness for studied samples have been determined. The influence of the deposition technology on film topography has been discussed.

  19. Continuing education on child development for primary healthcare professionals: a prospective before-and-after study

    Directory of Open Access Journals (Sweden)

    Amira Consuêlo Melo Figueiras

    Full Text Available CONTEXT AND OBJECTIVE: Children's developmental disorders are often identified late by healthcare professionals working in primary care. The aim of this study was to assess the impact of a continuing education program on child development, on the knowledge and practices of these professionals.DESIGN AND SETTING: Prospective single-cohort study (before-and-after study, conducted in the city of Belém, Pará , Brazil.METHODS: Two hundred and twenty-one professionals working in primary healthcare (82.2% participated in a continuing education program on child development and were assessed before and after implementation of the program through tests on their knowledge of child development, consisting of 19 questions for physicians and 14 for nurses, and questionnaires on their professional practices.RESULTS: One to three years after the program, the mean number of correct answers in the tests had increased from 11.5 to 14.3 among physicians in the Healthy Family Program (Programa Família Saudável, PFS; 13.0 to 14.3 among physicians in Municipal Health Units (Unidades Municipais de Saúde, UMS; 8.3 to 10.0 among PFS nurses; and 7.8 to 9.4 among UMS nurses. In interviews with mothers attended by these professionals before the program, only 21.7% reported that they were asked about their children's development, 24.7% reported that the professional asked about or observed their children's development and 11.1% received advice on how to stimulate them. After the program, these percentages increased to 34.5%, 54.2% and 30.3%, respectively.CONCLUSIONS: Professionals who participated in the program showed improved performance regarding child development knowledge and practices.

  20. Continuous positive airway pressure for bronchiolitis in a general paediatric ward; a feasibility study

    Science.gov (United States)

    2014-01-01

    Background Continuous positive airway pressure (CPAP) is commonly used to relieve respiratory distress in infants with bronchiolitis, but has mostly been studied in an intensive care setting. Our prime aim was to evaluate the feasibility of CPAP for infants with bronchiolitis in a general paediatric ward, and secondary to assess capillary PCO2 (cPCO2) levels before and during treatment. Methods From May 1st 2008 to April 30th 2012, infants with bronchiolitis at Stavanger University Hospital were treated with CPAP in a general paediatric ward, but could be referred to an intensive care unit (ICU) when needed, according to in-house guidelines. Levels of cPCO2 were prospectively registered before the start of CPAP and at approximately 4, 12, 24 and 48 hours of treatment as long as CPAP was given. We had a continuous updating program for the nurses and physicians caring for the infants with CPAP. The study was population based. Results 672 infants (3.4%) were hospitalized with bronchiolitis. CPAP was initiated in 53 infants (0.3%; 7.9% of infants with bronchiolitis), and was well tolerated in all but three infants. 46 infants were included in the study, the majority of these (n = 33) were treated in the general ward only. These infants had lower cPCO2 before treatment (8.0; 7.7, 8.6)(median; quartiles) than those treated at the ICU (n = 13) (9.3;8.5, 9.9) (p bronchiolitis may be feasible in a general paediatric ward, providing sufficient staffing and training, and the possibility of referral to an ICU when needed. PMID:24886569

  1. Experimental Study of Water Droplet Vaporization on Nanostructured Surfaces

    Science.gov (United States)

    Padilla, Jorge, Jr.

    This dissertation summarizes results of an experimental exploration of heat transfer during vaporization of a water droplet deposited on a nanostructured surface at a temperature approaching and exceeding the Leidenfrost point for the surface and at lower surface temperatures 10-40 degrees C above the saturated temperature of the water droplet at approximately 101 kPa. The results of these experiments were compared to those performed on bare smooth copper and aluminum surfaces in this and other studies. The nanostructured surfaces were composed of a vast array of zinc oxide (ZnO) nanocrystals grown by hydrothermal synthesis on a smooth copper substrate having an average surface roughness of approximately 0.06 micrometer. Various nanostructured surface array geometries were produced on the copper substrate by performing the hydrothermal synthesis for 4, 10 and 24 hours. The individual nanostructures were randomly-oriented and, depending on hydrothermal synthesis time, had a mean diameter of about 500-700 nm, a mean length of 1.7-3.3 micrometers,and porosities of approximately 0.04-0.58. Surface wetting was characterized by macroscopic measurements of contact angle based on the droplet profile and calculations based on measurements of liquid film spread area. Scanning electron microscope imaging was used to document the nanoscale features of the surface before and after the experiments. The nanostructured surfaces grown by hydrothermal synthesis for 4 and 24 hours exhibited contact angles of approximately 10, whereas the surfaces grown for 10 hours were superhydrophilic, exhibiting contact angles typically less than 3 degrees. In single droplet deposition experiments at 101 kPa, a high-speed video camera was used to document the droplet-surface interaction. Distilled and degassed water droplets ranging in size from 2.5-4.0 mm were deposited onto the surface from heights ranging from approximately 0.2-8.1 cm, such that Weber numbers spanned a range of approximately 0

  2. Experimental study of a two-phase surface jet

    Science.gov (United States)

    Perret, Matias; Esmaeilpour, Mehdi; Politano, Marcela S.; Carrica, Pablo M.

    2013-04-01

    Results of an experimental study of a two-phase jet are presented, with the jet issued near and below a free surface, parallel to it. The jet under study is isothermal and in fresh water, with air injectors that allow variation of the inlet air volume fraction between 0 and 13 %. Measurements of water velocity have been performed using LDV, and the jet exit conditions measured with PIV. Air volume fraction, bubble velocity and chord length distributions were measured with sapphire optical local phase detection probes. The mean free surface elevation and RMS fluctuations were obtained using local phase detection probes as well. Visualization was performed with laser-induced fluorescence. Measurements reveal that the mean free surface elevation and turbulent fluctuations significantly increase with the injection of air. The water normal Reynolds stresses are damped by the presence of bubbles in the bulk of the liquid, but very close to the free surface the effect is reversed and the normal Reynolds stresses increase slightly for the bubbly flow. The Reynolds shear stresses time it takes the bubbles to pierce the free surface, resulting in a considerable increase in the local air volume fraction. In addition to first explore a bubbly surface jet, the comprehensive dataset reported herein can be used to validate two-phase flow models and computational tools.

  3. Surface enhanced raman spectroscopy studies on triglycine sulphate single crystals

    Science.gov (United States)

    Parameswari, A.; Mohamed Asath, R.; Premkumar, R.; Milton Franklin Benial, A.

    2017-01-01

    Adsorption characteristics of triglycine sulphate (TGS) on silver (Ag) surface were investigated based on density functional theory calculations and surface enhanced Raman spectroscopy (SERS) technique. The single crystals of TGS were grown by slow evaporation method. Ag nanoparticles (Ag NPs) were prepared by solution combustion method and characterized. The calculated and observed structural parameters of TGS molecule were compared. Raman and SERS spectra for TGS single crystal were studied experimentally and validated theoretically. Frontier molecular orbitals (FMOs) analysis was carried out for TGS and TGS adsorbed on Ag surface. The second harmonic generation measurements confirm the nonlinear optical (NLO) activity of the TGS molecule. SERS spectral analysis reveals that the TGS adsorbed as tilted orientation on the silver surface. The theoretical and experimental results evidence the suitability of the grown TGS single crystal for optoelectronic applications.

  4. Study of surface charges in ballistic deflection transistors

    Science.gov (United States)

    Millithaler, J.-F.; Iñiguez-de-la-Torre, I.; Mateos, J.; GonzáIez, T.; Margala, M.

    2015-12-01

    This paper presents a comprehensive study of the behavior of surface charges in ballistic deflection transistors, at room temperature, where the in-plane geometry associating two drains with two gates in push-pull modes allows the control of electron path. Monte Carlo simulations were performed and compared with experimental data by using different models for accounting for surface charge effects. The simple model which assumes a constant and uniform value of the surface charge provides good results at equilibrium, but it is not able to correctly reproduce the BDT’s complex behavior when biased. We have confirmed that for a correct description of the device operation it is necessary to use a model allowing the surface charge to adapt itself locally to the carrier concentration in its surroundings.

  5. In situ ellipsometric study of surface immobilization of flagellar filaments

    Energy Technology Data Exchange (ETDEWEB)

    Kurunczi, S., E-mail: kurunczi@mfa.kfki.hu [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Nemeth, A.; Huelber, T. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Kozma, P. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Petrik, P. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Jankovics, H. [Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Sebestyen, A. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Vonderviszt, F. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Institute of Enzymology, Karolina ut 29-33, Budapest, H-1113 (Hungary); and others

    2010-10-15

    Protein filaments composed of thousands of subunits are promising candidates as sensing elements in biosensors. In this work in situ spectroscopic ellipsometry is applied to monitor the surface immobilization of flagellar filaments. This study is the first step towards the development of layers of filamentous receptors for sensor applications. Surface activation is performed using silanization and a subsequent glutaraldehyde crosslinking. Structure of the flagellar filament layers immobilized on activated and non-activated Si wafer substrates is determined using a two-layer effective medium model that accounted for the vertical density distribution of flagellar filaments with lengths of 300-1500 nm bound to the surface. The formation of the first interface layer can be explained by the multipoint covalent attachment of the filaments, while the second layer is mainly composed of tail pinned filaments floating upwards with the free parts. As confirmed by atomic force microscopy, covalent immobilization resulted in an increased surface density compared to absorption.

  6. A Metacognitive-Motivational Model of Surface Approach to Studying

    Science.gov (United States)

    Spada, Marcantonio M.; Moneta, Giovanni B.

    2012-01-01

    In this study, we put forward and tested a model of how surface approach to studying during examination preparation is influenced by the trait variables of motivation and metacognition and the state variables of avoidance coping and evaluation anxiety. A sample of 528 university students completed, one week before examinations, the following…

  7. An exploratory study assessing reasons behind initiation, continuation or stoppage of alcohol after first use

    Directory of Open Access Journals (Sweden)

    B S Chavan

    2015-01-01

    Full Text Available Objective: Few studies have investigated the reasons for alcohol initiation and continuation. The present study examined reasons for trying alcohol for the first time and its subsequent use. Furthermore, the study attempted to discover the possible predictors that make an individual vulnerable to alcohol use. Methodology: A total of 280 first-year college students from six different colleges were contacted. Using the method of equal probability, every third subject from each class was selected. All the selected subjects were interviewed and administered semi-structured questionnaire for gathering information regarding their experience with alcohol. Results: In our study, experimentation and peer pressure were found to be the main reasons for both alcohol use and its re-use. The first time drinkers differed a lot from those with multiple users in terms of reasons for trying alcohol, the effect of alcohol, family history of alcohol use, and self-view about alcohol use. The results depicted that the gender, educational stream, and family history of alcohol use are the factors that make an individual vulnerable to alcohol use. Conclusion: First-year of college is a unique transitional period. First-year students with high levels of sensation seeking may be especially at high-risk to begin or escalate heavy drinking. Studying the nature of alcohol initiation may not only be helpful in planning awareness programs but also in preventing underage drinking and alcohol abuse.

  8. Relationship preferences and experience of primary care patients in continuity of care: a case study in Beijing, China.

    Science.gov (United States)

    Liu, Chaojie; Wu, Yeqing; Chi, Xueyang

    2017-08-22

    Continuity of care can bring a wide range of benefits to consumers, providers and health care systems. This study aimed to understand the relationship preferences of primary care patients and their associations with patient experience of continuity of care. A questionnaire survey was conducted on 700 patients who sought medical care from a community health organisation in Beijing. The survey contained four items examining the relationship preferences of the respondents, and a modified Questionnaire of Continuity between Care Levels (CCAENA) measuring patient experience of continuity of care based on a three dimensional (relational, informational and managerial) model. The associations between the relationship preferences and the experience of respondents in continuity of care was tested using a linear regression model controlling for age, sex, education, medical insurance, personal income and servicing facilities. The respondents experienced relatively lower levels of informational and managerial continuity compared with relational continuity of care. More than 80% of respondents preferred free choice and a continuing relationship with doctors, compared with 59% who endorsed community facility control over hospital appointments. A preference for a continuing relationship with doctors was associated with all aspects of continuity of care. A preference in favour of community facility control over hospital appointments was a strong predictor of managerial continuity (β = 0.333, p  0.08). Perceived importance of information exchange was associated with relational and managerial continuity (p relationship with doctors. Relationship preferences of patients are associated with their experience of continuity of care. But patient strong preference for free choice of doctors is not aligned with relational continuity with primary care, a desirable feature of cost-effective healthcare systems.

  9. Development of virtual research environment for regional climatic and ecological studies and continuous education support

    Science.gov (United States)

    Gordov, Evgeny; Lykosov, Vasily; Krupchatnikov, Vladimir; Bogomolov, Vasily; Gordova, Yulia; Martynova, Yulia; Okladnikov, Igor; Titov, Alexander; Shulgina, Tamara

    2014-05-01

    measurements data and support profound statistical analysis of storaged and modeled on demand data. In particular, one can run the integrated models, preprocess modeling results data, using dedicated modules for numerical processing perform analysys and visualize obtained results. New functionality recently has been added to the statistical analysis tools set aimed at detailed studies of climatic extremes occurring in Northern Asia. The VRE element is also supporting thematic educational courses for students and post-graduate students of the Tomsk State University. In particular, it allow students to perform on-line thematic laboratory work cycles on the basics of analysis of current and potential future regional climate change using Siberia territory as an example (Gordova et al, 2013). We plan to expand the integrated models set and add comprehensive surface and Arctic Ocean description. Developed VRE element "Climate" provides specialists involved into multidisciplinary research projects with reliable and practical instruments for integrated research of climate and ecosystems changes on global and regional scales. With its help even a user without programming skills can process and visualize multidimensional observational and model data through unified web-interface using a common graphical web-browser. This work is partially supported by SB RAS project VIII.80.2.1, RFBR grant 13-05-12034, grant 14-05-00502, and integrated project SB RAS 131. References 1. Gordov E.P., Lykosov V.N., Krupchatnikov V.N., Okladnikov I.G., Titov A.G., Shulgina T.M. Computationaland information technologies for monitoring and modeling of climate changes and their consequences. Novosibirsk: Nauka, Siberian branch, 2013. - 195 p. (in Russian) 2. T.M. Shulgina, E.P. Gordov, I.G. Okladnikov, A.G., Titov, E.Yu. Genina, N.P. Gorbatenko, I.V. Kuzhevskaya,A.S. Akhmetshina. Software complex for a regional climate change analysis. // Vestnik NGU. Series: Information technologies. 2013. Vol. 11. Issue 1. P

  10. Use of surface electromyography in phonation studies: an integrative review

    Directory of Open Access Journals (Sweden)

    Balata, Patricia Maria Mendes

    2014-01-01

    Full Text Available Introduction: Surface electromyography has been used to assess the extrinsic laryngeal muscles during chewing and swallowing, but there have been few studies assessing these muscles during phonation. Objective: To investigate the current state of knowledge regarding the use of surface electromyography for evaluation of the electrical activity of the extrinsic muscles of the larynx during phonation by means of an integrative review. Method: We searched for articles and other papers in the PubMed, Medline/Bireme, and Scielo databases that were published between 1980 and 2012, by using the following descriptors: surface electromyography and voice, surface electromyography and phonation, and surface electromyography and dysphonia. The articles were selectedon the basis ofinclusion and exclusion criteria. Data Synthesis: This was carried out with a cross critical matrix. We selected 27 papers,i.e., 24 articles and 3 theses. The studies differed methodologically with regards to sample size and investigation techniques, making it difficult to compare them, but showed differences in electrical activity between the studied groups (dysphonicsubjects, non-dysphonicsubjects, singers, and others. Conclusion: Electromyography has clinical applicability when technical precautions with respect to application and analysis are obeyed. However, it is necessary to adopt a universal system of assessment tasks and related measurement techniques to allow comparisons between studies.

  11. Study of Magnetohydrodynamic Surface Waves on Liquid Gallium

    Energy Technology Data Exchange (ETDEWEB)

    Hantao Ji; William Fox; David Pace; H.L. Rappaport

    2004-05-13

    Magnetohydrodynamic (MHD) surface waves on liquid gallium are studied theoretically and experimentally in the small magnetic Reynolds number limit. A linear dispersion relation is derived when a horizontal magnetic field and a horizontal electric current is imposed. No wave damping is found in the shallow liquid limit while waves always damp in the deep liquid limit with a magnetic field parallel to the propagation direction. When the magnetic field is weak, waves are weakly damped and the real part of the dispersion is unaffected, while in the opposite limit waves are strongly damped with shortened wavelengths. In a table-top experiment, planar MHD surface waves on liquid gallium are studied in detail in the regime of weak magnetic field and deep liquid. A non-invasive diagnostic accurately measures surface waves at multiple locations by reflecting an array of lasers off the surface onto a screen, which is recorded by an Intensified-CCD camera. The measured dispersion relation is consistent with the linear theory with a reduced surface tension likely due to surface oxidation. In excellent agreement with linear theory, it is observed that surface waves are damped only when a horizontal magnetic field is imposed parallel to the propagation direction. No damping is observed under a perpendicular magnetic field. The existence of strong wave damping even without magnetic field suggests the importance of the surface oxide layer. Implications to the liquid metal wall concept in fusion reactors, especially on the wave damping and a Rayleigh-Taylor instability when the Lorentz force is used to support liquid metal layer against gravity, are discussed.

  12. Hydrogenation of nitriles on a well-characterized nickel surface: From surface science studies to liquid phase catalytic activity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gardin, D.E.

    1993-12-01

    Nitrile hydrogenation is the most commonly used method for preparing diverse amines. This thesis is aimed at the mechanism and factors affecting the performance of Ni-based catalysts in nitrile hydrogenations. Surface science techniques are used to study bonding of nitriles and amines to a Ni(111) surface and to identify surface intermediates. Liquid-phase hydrogenations of cyclohexene and 1-hexene on a Pt foil were carried out successfully. Finally, knowledge about the surface structure, surface chemical bond, dynamics of surface atoms (diffusion, growth), and reactivity of metal surfaces from solid-gas interface studies, is discussed.

  13. Continuous shear - a method for studying material elements passing a stationary shear plane

    DEFF Research Database (Denmark)

    Lindegren, Maria; Wiwe, Birgitte; Wanheim, Tarras

    2003-01-01

    Traditionally, material response to shear deformation has been studied with methods where the shear is gradually increasing from zero to the final value over a certain fixed deformation zone, e.g. in the well-known torsion test of a tube with a defined shear zone established by a machined...... circumferential groove. Normally shear in metal forming processes is of another nature, namely where the material elements move through a stationary shear zone, often of small width. In this paper a method enabling the simulation of this situation is presented. A tool for continuous shear has beeen manufactured...... and tested with AlMgSil and copper. The sheared material has thereafter been tested n plane strain compression with different orientation concerning the angle between the shear plane and the compression direction....

  14. Study of the behavior of actinides continuously recycled in a hard spectrum reactor

    Energy Technology Data Exchange (ETDEWEB)

    Schofield, P.E.

    1980-12-01

    The behavior of actinides continuously recycled through the central region of an EBR-II type reactor was studied. Such a reactor would convert long-lived nuclear wastes to short-lived isotopes, and simultaneously produce useful power. This process is proposed as an alternative to the geological isolation of long-lived actinide wastes. A driver region of 50% U-235 enriched fuel provided a nearly-constant spectrum and flux that was extremely hard compared to standard LMFBRs. This resulted in a high fission-to-capture ratio for most isotopes. The original actinide fuel was the discharge from a LWR, cooled for two years, with 99.9% of the uranium and plutonium removed by chemical processing. Comparison was made between removal of both Pu and U and removal of only U in subsequent cycles. The latter case resulted in substantial quantities of trans-plutonics burned per cycle.

  15. Integrated vibration-based maintenance: an approach for continuous reduction in LCC. A case study

    Energy Technology Data Exchange (ETDEWEB)

    Najjar, B. [ER Konsult Utveckling AB, Vaexjoe (Sweden)

    1998-12-31

    The biggest thread in achieving and maintaining high equipment effectiveness can be stated as: whether the improved manufacturing processes capable of producing quality products at a competitive cost. The effect of a new vibration-based maintenance concept, called Total Quality Maintenance (TQMain), is introduced. It aims to make intensive use of the real-time data acquisition and analysis to detect causes behind product quality deviation and failures in machinery, and following defect development at an early stage to increase machine mean effective life and improve company`s economics. The effect of TQMain on LCC of machinery and company`s economics is discussed. A case study to reveal savings in maintenance cost when a vibration-based policy involved, is presented. Using TQMain, company`s economics can be improved effectively through continuous improvement of the technical and economic effectiveness of production processes. (orig.) 14 refs.

  16. Continuous improvement, burnout and job engagement: a study in a Dutch nursing department.

    Science.gov (United States)

    Benders, Jos; Bleijerveld, Hans; Schouteten, Roel

    2016-05-27

    Continuous improvement (CI) programs are potentially powerful means to improve the quality of care. The more positive nurses perceive these programs' effects, the better they may be expected to cooperate. Crucial to this perception is how nurses' quality of working life is affected. We studied this in a nursing department, using the job demands-resources model. We found that two job demands improved, and none of the job resources. Job engagement did not change significantly, while the burnout risk decreased slightly. Overall, the nurses felt the impact to be small yet the changes were in a positive direction. CI can thus be used to improve nurses' working lives and, by restructuring the work processes, the quality of care. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Biological production of ethanol from coal. Task 4 report, Continuous reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    1992-10-01

    The production of ethanol from synthesis gas by the anaerobic bacterium C. ljungdahlii has been demonstrated in continuous stirred tank reactors (CSTRs), CSTRs with cell recycle and trickle bed reactors. Various liquid media were utilized in these studies including basal medium, basal media with 1/2 B-vitamins and no yeast extract and a medium specifically designed for the growth of C. ljungdahlii in the CSTR. Ethanol production was successful in each of the three reactor types, although trickle bed operation with C. ljungdahlii was not as good as with the stirred tank reactors. Operation in the CSTR with cell recycle was particularly promising, producing 47 g/L ethanol with only minor concentrations of the by-product acetate.

  18. Imaging study of a phase-sensitive breast-CT system in continuous acquisition mode

    Science.gov (United States)

    Delogu, P.; Golosio, B.; Fedon, C.; Arfelli, F.; Bellazzini, R.; Brez, A.; Brun, F.; Di Lillo, F.; Dreossi, D.; Mettivier, G.; Minuti, M.; Oliva, P.; Pichera, M.; Rigon, L.; Russo, P.; Sarno, A.; Spandre, G.; Tromba, G.; Longo, R.

    2017-01-01

    The SYRMA-CT project aims to set-up the first clinical trial of phase-contrast breast Computed Tomography with synchrotron radiation at the SYRMEP beamline of Elettra, the Italian synchrotron light source. The challenge in a dedicated breast CT is to match a high spatial resolution with a low dose level. In order to fulfil these requirements, the SYRMA-CT project uses a large area CdTe single photon counting detector (Pixirad-8), simultaneous algebraic reconstruction technique (SART) and phase retrieval pre-processing. This work investigates the imaging performances of the system in a continuous acquisition mode and with a low dose level towards the clinical application. A custom test object and a large surgical sample have been studied.

  19. Continuous Auditory Feedback of Eye Movements: An Exploratory Study toward Improving Oculomotor Control

    Directory of Open Access Journals (Sweden)

    Eric O. Boyer

    2017-04-01

    Full Text Available As eye movements are mostly automatic and overtly generated to attain visual goals, individuals have a poor metacognitive knowledge of their own eye movements. We present an exploratory study on the effects of real-time continuous auditory feedback generated by eye movements. We considered both a tracking task and a production task where smooth pursuit eye movements (SPEM can be endogenously generated. In particular, we used a visual paradigm which enables to generate and control SPEM in the absence of a moving visual target. We investigated whether real-time auditory feedback of eye movement dynamics might improve learning in both tasks, through a training protocol over 8 days. The results indicate that real-time sonification of eye movements can actually modify the oculomotor behavior, and reinforce intrinsic oculomotor perception. Nevertheless, large inter-individual differences were observed preventing us from reaching a strong conclusion on sensorimotor learning improvements.

  20. Study on Compatibility between Converters and Casting Machines for Daily Steelmaking and Continuous Casting Scheduling

    Institute of Scientific and Technical Information of China (English)

    MA Feng-cai; ZHANG Qun

    2009-01-01

    In this paper, daily production scheduling is studied based on the Third Steelmaking Plant of Wuhan Iron and steel corporation (WISCO). To make sure the daily production plan is feasible, method of casting gToup is established, and the compatibility between two converters and three continuous casting devices in the Third Steelmaking Plant of WISCO is analyzed. The process flow chart of daily production scheduling is given in this paper. Then, algorithms and procedures for the simulation of daily production plan is developed. Using the actual data from the Third Steelmaking Plant, the feasible daily steelmaking plan and cast plan are given. The plan contains 7 groups of cast plan, figured out 54 converters, and a- bout 13,500 tons steel.

  1. Study on deformation and microstructure characterizations of mild steel joints by continuous drive friction welding

    Institute of Scientific and Technical Information of China (English)

    Li Wenya; Yu Min; Li Jinglong; Gao Dalu

    2009-01-01

    Macro-deformation characteristics of continuous drive friction welded mild steel joints were examined by using one deformable workpiece (objective) and the other undeformable one (rigid). The microstructure evolution and hardness change across the joint were studied. The results show that the axial shortening and radial increment of joints increase with increasing the friction time at 1 200rpm. The cementite particles of pearlites in the weld center are uniformly distributed on the ferrite matrix, while the cementites of the pearlite in the thermal-mechanically affected zone are broken and discontinuously dispersed in the pearlite. The hardness decreases rapidly from the weld center to the parent metal under the coupled effects of heat and deformation during the rapid heating and cooling processes.

  2. A detection system for charged-particle decay studies with a continuous-implantation method

    Energy Technology Data Exchange (ETDEWEB)

    Sun, L.J. [China Institute of Atomic Energy, Beijing 102413 (China); Xu, X.X., E-mail: xuxinxing@ciae.ac.cn [China Institute of Atomic Energy, Beijing 102413 (China); Lin, C.J., E-mail: cjlin@ciae.ac.cn [China Institute of Atomic Energy, Beijing 102413 (China); Wang, J.S. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Fang, D.Q. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, Z.H. [School of Physic and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Wang, Y.T. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, J. [School of Physic and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Yang, L.; Ma, N.R. [China Institute of Atomic Energy, Beijing 102413 (China); Wang, K. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Zang, H.L. [School of Physic and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Wang, H.W.; Li, C.; Shi, C.Z.; Nie, M.W.; Li, X.F.; Li, H. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Ma, J.B.; Ma, P. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); and others

    2015-12-21

    A new detection system with high detection efficiency and low detection threshold has been developed for charged-particle decay studies, including β-delayed proton, α decay or direct proton emission from proton-rich nuclei. The performance was evaluated by using the β-delayed proton emitter {sup 24}Si produced by projectile fragmentation at the First Radioactive Ion Beam Line in Lanzhou. Under a continuous-beam mode, the isotopes of interest were implanted into two double-sided silicon strip detectors, where the subsequent decays were measured and correlated to the preceding implantations by using position and time information. The system allows us to measure protons with energies down to about 200 keV without obvious β background in the proton spectrum. Further application of the detection system can be extended to the measurements of β-delayed proton decay and the direct proton emission of more exotic proton-rich nuclei.

  3. A perturbative study on the analytic continuation for generalized gravitational entropy

    CERN Document Server

    Prudenziati, Andrea

    2014-01-01

    We study the analytic continuation used by Lewkowycz and Maldacena to prove the Ryu-Takayanagi formula for entanglement entropy, which is the holographic dual of the trace of the $\\beta$-power of the time evolution operator when $\\beta\\in \\mathbb{R}$. This will be done perturbatively by using a weakly time dependent Hamiltonian, corresponding to a small shift of the dual static background. Depending on the periodicity we impose on the gravitational solution, we consider two different possibilities and compare the associated entropies with the results obtained through a minimal area computation. To our surprise we discover that, at first order, both choices correctly reproduce the associated entanglement entropy. Furthermore we find unexpected divergent contributions that we have to discard in order to fit the minimal area computation, and an additional requirement that needs to be imposed on the $\\beta$ dependence on the metric.

  4. a Surface Study of Mercury-Cadmium Telluride.

    Science.gov (United States)

    Lopes, Vincent C.

    Single crystals of Hg(,1-x)Cd(,x)Te were studied to determine how changes in the surface conditions affected electrical properties. Infrared detector grade material from Honeywell Radiation Center (x = 0.2, bandgap near 10(mu)m) was used to examine the effects of changes in the surface charge density on electrical l/f noise. The surface charge density which was controlled by the pH of the aqueous solution was measured in a zeta meter which operated much like a Millikan oil drop experiment. The electrophoresis zeta potential measurements on (HgCd)Te have identified the active surface oxide as TeO(,2) and has also revealed information on the surface chemistry. An experimental fit yielded the dissociation constant of tellurous acid which was the result of TeO(,2) combining with H(,2)O. The dissociation of tellurous acid was responsible for the measured surface charge densities and the surface chemistry from pH = 1 to pH = 8. At pH = 1, the surface was H(,3)TeO(,3)('+). At pH = 1.5, the surface was H(,2)TeO(,3) which gave the neutral point, PZZP (Point of Zero Zeta Potential). With the pH between 2 and 6, the surface was HTeO(,3)('-). As the pH was changed to 7 and greater, the surface was TeO(,3)-. Electrical l/f noise in (HgCd)Te was found to be dominated by bulk and not surface effects at room temperature. l/f noise measure- ments were made in an air ambient and in various electrolytic solu- tions which produced different surface charge conditions. The l/f noise voltage did not change within experimental error as the surface charge density was changed (due to major changes in the surface chemistry) by pH; at pH = 7, ((sigma)(,s) = -3 x 10('12) e/cm('2) due to TeO(,3)-), with the pH between 2 and 6 (-1 x 10('12) e/cm('2) < (sigma)(,s) < -2 x 10('12) e/cm('2) due to HTeO(,3)('-)), and to pH = 1.5 ((sigma)(,s) = 0 due to H(,2)TeO(,3)). Laser Raman and Auger spectroscopy were used to assess mechanical surface damage and anodic oxide composition. Surface damage on (Hg

  5. Causal inference in longitudinal comparative effectiveness studies with repeated measures of a continuous intermediate variable.

    Science.gov (United States)

    Wang, Chen-Pin; Jo, Booil; Brown, C Hendricks

    2014-09-10

    We propose a principal stratification approach to assess causal effects in nonrandomized longitudinal comparative effectiveness studies with a binary endpoint outcome and repeated measures of a continuous intermediate variable. Our method is an extension of the principal stratification approach originally proposed for the longitudinal randomized study "Prevention of Suicide in Primary Care Elderly: Collaborative Trial" to assess the treatment effect on the continuous Hamilton depression score adjusting for the heterogeneity of repeatedly measured binary compliance status. Our motivation for this work comes from a comparison of the effect of two glucose-lowering medications on a clinical cohort of patients with type 2 diabetes. Here, we consider a causal inference problem assessing how well the two medications work relative to one another on two binary endpoint outcomes: cardiovascular disease-related hospitalization and all-cause mortality. Clinically, these glucose-lowering medications can have differential effects on the intermediate outcome, glucose level over time. Ultimately, we want to compare medication effects on the endpoint outcomes among individuals in the same glucose trajectory stratum while accounting for the heterogeneity in baseline covariates (i.e., to obtain 'principal effects' on the endpoint outcomes). The proposed method involves a three-step model estimation procedure. Step 1 identifies principal strata associated with the intermediate variable using hybrid growth mixture modeling analyses. Step 2 obtains the stratum membership using the pseudoclass technique and derives propensity scores for treatment assignment. Step 3 obtains the stratum-specific treatment effect on the endpoint outcome weighted by inverse propensity probabilities derived from Step 2.

  6. A new finite element model in studying earthquake triggering and continuous evolution of stress field

    Institute of Scientific and Technical Information of China (English)

    HU CaiBo; ZHOU YiJie; CAI YongEn

    2009-01-01

    In this paper, a new finite element model (FEM) In consideration of regional stress field and an earthquake triggering factor C are proposed for studying earthquake triggering and stress field evolution in an earthquake sequence. The factor C is defined as a ratio between the shear stress and the frictional strength on a slip surface, and it can be used to tell if earthquake is triggered or not. The new FEM and the factor C are used to study the aftershock triggering of the 1976 Tangshan earthquake sequence. The results indicate that the effects of the stress field and the heterogeneity of the Tangshan earthquake fault zone on the aftershock triggering are very important. The affershocks fallen in the earthquake triggering regions predicted by the new FEM are more than those fallen in the regions of △CFS≥0 predicted by seismic dislocation theory.

  7. A new finite element model in studying earthquake triggering and continuous evolution of stress field

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, a new finite element model (FEM) in consideration of regional stress field and an earthquake triggering factor C are proposed for studying earthquake triggering and stress field evolution in an earthquake sequence. The factor C is defined as a ratio between the shear stress and the frictional strength on a slip surface, and it can be used to tell if earthquake is triggered or not. The new FEM and the factor C are used to study the aftershock triggering of the 1976 Tangshan earthquake sequence. The results indicate that the effects of the stress field and the heterogeneity of the Tangshan earthquake fault zone on the aftershock triggering are very important. The aftershocks fallen in the earthquake triggering regions predicted by the new FEM are more than those fallen in the regions of ΔCFS≥ 0 predicted by seismic dislocation theory.

  8. Quality of pharmacokinetic studies in critically ill patients receiving continuous renal replacement therapy.

    Science.gov (United States)

    Vaara, S; Pettila, V; Kaukonen, K-M

    2012-02-01

    Continuous renal replacement therapy (CRRT) is the preferred renal replacement therapy modality in the critically ill. We aimed to reveal the literature on the pharmacokinetic studies in critically ill patients receiving CRRT with special reference to quality assessment of these studies and the CRRT dose. We conducted a systematic review by searching the MEDLINE, EMBASE, and the Cochrane databases to December 2009 and bibliographies of relevant review articles. We included original studies reporting from critically ill adult subjects receiving CRRT because of acute kidney injury with a special emphasis on drug pharmacokinetics. We used the minimum reporting criteria for CRRT studies by Acute Dialysis Quality Initiative (ADQI) and, second, the Downs and Black checklist to assess the quality of the studies. We calculated the CRRT dose per study. We included pharmacokinetic parameters, residual renal function, and recommendations on drug dosing. Of 182 publications, 95 were considered relevant and 49 met the inclusion criteria. The median [interquartile range (IQR)] number of reported criteria by ADQI was 7.0 (5.0-8.0) of 12. The median (IQR) Downs and Black quality score was 15 (14-16) of 32. None of the publications reported CRRT dose directly. The median (IQR) weighted CRRT dose was 23.7 (18.8-27.9) ml/kg/h. More attention should be paid both to standardizing the CRRT dose and reporting of the CRRT parameters in pharmacokinetic studies. The general quality of the studies during CRRT in the critically ill was only moderate and would be greatly improved by reports in concordant with the ADQI recommendations. © 2011 The Authors Acta Anaesthesiologica Scandinavica © 2011 The Acta Anaesthesiologica Scandinavica Foundation.

  9. Growth model and metabolic activity of brewing yeast biofilm on the surface of spent grains: a biocatalyst for continuous beer fermentation.

    Science.gov (United States)

    Brányik, Tomás; Vicente, António A; Kuncová, Gabriela; Podrazký, Ondrej; Dostálek, Pavel; Teixeira, José A

    2004-01-01

    In the continuous systems, such as continuous beer fermentation, immobilized cells are kept inside the bioreactor for long periods of time. Thus an important factor in the design and performance of the immobilized yeast reactor is immobilized cell viability and physiology. Both the decreasing specific glucose consumption rate (q(im)) and intracellular redox potential of the cells immobilized to spent grains during continuous cultivation in bubble-column reactor implied alterations in cell physiology. It was hypothesized that the changes of the physiological state of the immobilized brewing yeast were due to the aging process to which the immobilized yeast are exposed in the continuous reactor. The amount of an actively growing fraction (X(im)act) of the total immobilized biomass (X(im)) was subsequently estimated at approximately X(im)act = 0.12 g(IB) g(C)(-1) (IB = dry immobilized biomass, C = dry carrier). A mathematical model of the immobilized yeast biofilm growth on the surface of spent grain particles based on cell deposition (cell-to-carrier adhesion and cell-to-cell attachment), immobilized cell growth, and immobilized biomass detachment (cell outgrowth, biofilm abrasion) was formulated. The concept of the active fraction of immobilized biomass (X(im)act) and the maximum attainable biomass load (X(im)max) was included into the model. Since the average biofilm thickness was estimated at ca. 10 microm, the limitation of the diffusion of substrates inside the yeast biofilm could be neglected. The model successfully predicted the dynamics of the immobilized cell growth, maximum biomass load, free cell growth, and glucose consumption under constant hydrodynamic conditions in a bubble-column reactor. Good agreement between model simulations and experimental data was achieved.

  10. Kinetic Study of Acetone-Butanol-Ethanol Fermentation in Continuous Culture

    OpenAIRE

    Buehler, Edward A.; Mesbah, Ali

    2016-01-01

    Acetone-butanol-ethanol (ABE) fermentation by clostridia has shown promise for industrial-scale production of biobutanol. However, the continuous ABE fermentation suffers from low product yield, titer, and productivity. Systems analysis of the continuous ABE fermentation will offer insights into its metabolic pathway as well as into optimal fermentation design and operation. For the ABE fermentation in continuous Clostridium acetobutylicum culture, this paper presents a kinetic model that inc...

  11. Numerical study of three-dimensional free surface dynamics

    Institute of Scientific and Technical Information of China (English)

    Baozeng Yue; Zhaolin Wang

    2006-01-01

    The dynamic problem of three-dimensional free surface is numerically studied in this paper.The ALE (Arbitrary Lagrange-Euler) kinematic description is introduced into the control equation system.The ALE description method is used to track free surface.Accurate formulations for calculating the normal vector on the free surface are presented.The discrete numerical equations by finite element method are developed by Galerkin weighted residual method.The boundary condition about free-surface tension is represented in the form of weak integration that can be computed by a differential geometry method derived in the present paper.The effect of contact angle is incorporated in the numerical algorithm.Furthermore, the numerical computations are performed and the comparison between computational and analytical results validated the effectiveness of the method.The results of this paper provide a fundamental understandings of the dynamics of liquid free surfaces,in which the surface tension and contact angle boundary conditions are taken into account.Finally,numerical simulation of largescale amplitude sloshing of liquid in a cylindrical container is performed and a numerical analysis of the effect of an annular ring-shaped rigid damping baffle on liquid sloshing oscillations in a cylindrical tank is also carried out.

  12. Universal Design and Continuing Professional Development for Architects: An Irish Case Study.

    Science.gov (United States)

    Shea, Eoghan C O; Basnak, Megan; Bucholz, Merritt; Steinfeld, Edward

    2016-01-01

    The Tomar Resolution urged that all occupations working in the built environment be educated in the principles and measures of Universal Design in order to facilitate all people playing a full role in society. For Architects and Architectural Technologists, under-graduate education will continue to have a major role to play. At the same time in the Republic of Ireland, and in an ever-growing number of other jurisdictions, Continuous Professional Development (CPD) is a requirement for all Architects and Architectural Technologists and can significantly affect knowledge, skill and competence in a number of subjects including Universal Design. This paper looks at the results of a recent survey of Architects and Architectural Technologists practising in Ireland, architectural educators, and client bodies that sought to assess the following: 1. How inherent is Universal Design knowledge to current building design practice? 2. What are the current Universal Design education and training needs of Architects and Architectural Technologists practising in Ireland? 3. Which Universal Design themes and topics are of most interest to Architects and Architectural Technologists practising in Ireland? 4. To what extent does existing CPD for Architects and Architectural Technologists practising in Ireland address Universal Design topics? 5. What can motivate Architects and Architectural Technologists practising in Ireland to access Universal Design CPD? 6. What are the most effective means by which to deliver Universal Design CPD to Architects and Architectural Technologists practising in Ireland? The survey discussed in this paper is one phase of a longer study aimed at providing a research base for developing CPD in Universal Design for Architects and Architectural Technologists practising in Ireland.

  13. How does hospitalization affect continuity of drug therapy: an exploratory study

    Science.gov (United States)

    Blozik, Eva; Signorell, Andri; Reich, Oliver

    2016-01-01

    Introduction Transitions between different levels of health care, such as hospital admission and discharge, pose a significant threat to the quality and continuity of medication therapy. This study aims to explore the role of hospitalization on medication changes as patients are transferred from and back to ambulatory care. Methods Secondary analysis of claims data from Swiss residents with basic health insurance at the Helsana Group was performed. We evaluated medication invoices of patients who were hospitalized in a Swiss private hospital group in the year 2013. Medication changes were defined as discontinuation, new prescription, or change in the Anatomical Therapeutic Chemical (ATC) Classification System level 4, which is equivalent to a change in the chemical/therapeutic/pharmacological subgroup. Multiple Poisson regression analysis was applied to evaluate whether medication change was predicted by socioeconomic or clinical patient characteristics or by a system factor (physician dispensing of medication allowed in canton of residence). Results We investigated a total of 10,123 hospitalized patients, among whom a mean number of 3.85 (median 3.00) changes were identified. Change most frequently affected antihypertensives, analgesics, and antirheumatics. If patients were enrolled in a managed care plan, they were less likely to undergo changes. If a patient resided in a canton, in which physicians were allowed to dispense medication directly, the patient was more likely to experience change. Conclusion There is considerable change in medication when patients shift between ambulatory and inpatient health care levels. This interruption of medication continuity is in part desirable as it responds to clinical needs. However, we hypothesize that there is also a significant proportion of change due to unwarranted factors such as financial incentives for change of products. PMID:27578981

  14. Effective continuing professional development for translating shared decision making in primary care: A study protocol

    Science.gov (United States)

    2010-01-01

    Background Shared decision making (SDM) is a process by which a healthcare choice is made jointly by the healthcare professional and the patient. SDM is the essential element of patient-centered care, a core concept of primary care. However, SDM is seldom translated into primary practice. Continuing professional development (CPD) is the principal means by which healthcare professionals continue to gain, improve, and broaden the knowledge and skills required for patient-centered care. Our international collaboration seeks to improve the knowledge base of CPD that targets translating SDM into the clinical practice of primary care in diverse healthcare systems. Methods Funded by the Canadian Institutes of Health Research (CIHR), our project is to form an international, interdisciplinary research team composed of health services researchers, physicians, nurses, psychologists, dietitians, CPD decision makers and others who will study how CPD causes SDM to be practiced in primary care. We will perform an environmental scan to create an inventory of CPD programs and related activities for translating SDM into clinical practice. These programs will be critically assessed and compared according to their strengths and limitations. We will use the empirical data that results from the environmental scan and the critical appraisal to identify knowledge gaps and generate a research agenda during a two-day workshop to be held in Quebec City. We will ask CPD stakeholders to validate these knowledge gaps and the research agenda. Discussion This project will analyse existing CPD programs and related activities for translating SDM into the practice of primary care. Because this international collaboration will develop and identify various factors influencing SDM, the project could shed new light on how SDM is implemented in primary care. PMID:20977774

  15. Comparative study of anticoagulation versus saline flushes in continuous renal replacement therapy

    Directory of Open Access Journals (Sweden)

    Nagarik Amit

    2010-01-01

    Full Text Available Systemic heparinization during continuous renal replacement therapy (CRRT is associated with disadvantage of risk of bleeding. This study analyses the efficacy of frequent saline flushes compared with heparin anticoagulation to maintain filter life. From January 2004 to November 2007, 65 critically ill patients with acute renal failure underwent CRRT. Continuous venovenous hemodialfiltration (CVVHDF was performed using Diapact Braun CRRT machine. 1.7% P.D. fluid was used as dialysate. 0.9% NS with addition of 10% Ca Gluconate, Magnesium Sulphate, Soda bicarbonate and Potassium Chloride added sequentially in separate units were used for replacement, carefully monitoring their levels. Anticoagulation of extracorporeal circuit was achieved with unfractionated heparin (250-500 units alternate hour in 35 patients targeting aPTT of 45-55 seconds. No anticoagulation was used in 30 patients with baseline APTT > 55 seconds and extracorporeal circuit was maintained with saline flushes at 30 min interval. 65 pa-tients including 42 males. Co-morbidities were comparable in both groups. HMARF was signifi-cantly more common in heparin group while Sepsis was comparable in both the groups. CRRT parameters were similar in both groups. Average filter life in heparin group was 26 ± 6.4 hours while it was 24.5 ± 6.36 hours in heparin free group ( P=NS. Patients receiving heparin had 16 bleeding episodes (0.45/patient while only four bleeding episodes occurred in heparin free group (0.13/patient, P< 0.05. Mortality was 71% in heparin group and 67% in heparin free group. Frequent saline flushes is an effective mode of maintainance of extracorporeal circuit in CRRT when aPTT is already on the higher side, with significantly decreased bleeding episodes.

  16. Experimental study on oscillating grid turbulence and free surface fluctuation

    Science.gov (United States)

    Chiapponi, Luca; Longo, Sandro; Tonelli, Mara

    2012-11-01

    This paper analyses the interaction between the turbulence and free surface. The phenomenon takes place in many natural flows and industrial processes. In the present experiments, turbulence is generated by a vertically oscillating grid moving beneath the free surface. Fluid velocity has been measured through a hot-film anemometer, and the free surface elevation has been measured by an ultrasonic sensor. Integral length scales and several turbulence estimators have been computed. In order to detect the generation of turbulence near the free surface, the correlation between free surface elevation and the underneath flow velocity has been studied, as well as the time lag between turbulence and free surface. The free surface dynamics has been characterized by a velocity scale and a length scale. The kinetic energy associated with the free surface fluctuations increases with the Reynolds number at a rate depending on the frequency of the grid movement. For Reynolds number larger than ≈1000, however, the relationships collapse to a single curve characterized by a lower rate. The present experiments do not achieve the inertial sub-range in the vertical velocity fluctuations, and the estimated spectrum decays with an exponent smaller than -3, which is the typical value for the two-dimensional turbulence in the inertial sub-range. The macro length scale, estimated by using the Taylor's frozen turbulence hypothesis, experiences a decay away from the grid, which follows reasonably well the profile of Thompson and Turner (J Fluid Mechanics 67: 349-368, 1975). The micro length scale reduces immediately beneath the free surface, which can be interpreted by the increase of dissipation rate in the subsurface layer. The classification diagram by Brocchini and Peregrine (J Fluid Mech 449: 225-254, 2001) indicates that most tests fall in the weak turbulence domain, but some tests fall in the wavy domain. The vertical velocity fluctuations and the free surface level show a

  17. Study on contaminants on flight and other critical surfaces

    Science.gov (United States)

    Workman, Gary L.; Hughes, Charles; Arendale, William F.

    1994-01-01

    The control of surface contamination in the manufacture of space hardware can become a critical step in the production process. Bonded surfaces have been shown to be affected markedly by contamination. It is important to insure surface cleanliness by preventing contamination prior to bonding. In this vein techniques are needed in which the contamination which may affect bonding are easily found and removed. Likewise, if materials which are detrimental to bonding are not easily removed, then they should not be used in the manufacturing process. This study will address the development of techniques to locate and quantify contamination levels of particular contaminants. With other data becoming available from MSFC and its contractors, this study will also quantify how certain contaminants affect bondlines and how easily they are removed in manufacturing.

  18. A STUDY OF CONTINUING EDUCATION NEEDS OF SELECTED PROFESSIONAL GROUPS AND UNIVERSITY EXTENSION CONTRACT PROGRAMS IN WYOMING.

    Science.gov (United States)

    NICHOLAS, ROBERT A.

    THIS STUDY AIMED TO DEVELOP PRINCIPLES FOR A MODEL PROGRAM OF CONTINUING EDUCATION FOR THE PROFESSIONS AT THE UNIVERSITY OF WYOMING. THE AUTHOR REVIEWED THE LITERATURE ON THE GROWTH OF THE PROFESSIONS AND ON CONTINUING EDUCATION IN THE PROFESSIONS GENERALLY, WITH SPECIAL REFERENCE TO ARCHITECTURE, DENTISTRY, LAW, MEDICINE, AND PHARMACY. FROM THIS…

  19. A study of biofunctionalized silica nanospring surface for immunosensor applications

    Science.gov (United States)

    Timalsina, Yukta P.; McIlroy, David N.

    2012-02-01

    A study of biofunctionalized VANS (vertically aligned (silica) nanospring) surface for immunosensor applications is presented. VANS surface treated with 3-aminopropyltriethoxysilane (APTES) leaves a primary amine groups on the VANS surface. Glutaraldehyde (GA) reacts with APTES modified VANS surface forming imine bonds at one end of glutaraldehyde, leaving aldehyde groups at the other end to react with the antibody. X-ray photoelectron study verifies each step of VANS surface functionalization. A goat anti mouse antibody (GαM IgG I) is immobilized as a biorecognition layer on the APTES-GA modified surface and targeted to mouse IgG. It is investigated that mouse IgG captured from the solution phase specifically binds to goat anti mouse IgG on APTES-GA- GαM IgG I. Then layer of GαM IgG II attached to the APTES-GA- GαM IgG I-mouse IgG surface reacts only when there is mouse IgG instead of rabbit IgG. A modeling of a resistor-inductor-capacitor (RLC) circuit of impedance spectra measured after the addition of successive layer indicates the these biological layers behave as insulating layers. It is explored that there is a greater magnitude of change between successive bio-layers below 10 kHz. Changes in the magnitudes of the elements of the RLC equivalent circuit indicate that the addition of biological layers impedes ionic motion thereby changing the effective dielectric response by the biomolecule polarization.

  20. Study on Dielectric Function Models for Surface Plasmon Resonance Structure

    Directory of Open Access Journals (Sweden)

    Peyman Jahanshahi

    2014-01-01

    Full Text Available The most common permittivity function models are compared and identifying the best model for further studies is desired. For this study, simulations using several different models and an analytical analysis on a practical surface Plasmon structure were done with an accuracy of ∼94.4% with respect to experimental data. Finite element method, combined with dielectric properties extracted from the Brendel-Bormann function model, was utilized, the latter being chosen from a comparative study on four available models.

  1. Theoretical Study of Mercury Species Adsorption on CaO(100) Surface

    Science.gov (United States)

    Zhang, Chong; Liu, Yu; Zhao, Li; Cui, Min-Shu; Lu, Qiang

    2017-05-01

    As an important air pollutant, mercury produced by power generation can be captured by CaO incoal-firedfly ash. In order to understand the interaction mechanism of CaO with mercury in HCl atmosphere, the density functional theory method is utilizedto investigate the adsorption of mercury species on the fly ash components. The CaO(100) surface is built to study the stable adsorption configurations of Hg0, HCl, HgCl and HgCl2 on all possible adsorption sites. The results show that CaO(100) surface cannot absorb Hg0 directly, but the intermediate HgCl can be adsorbed on the surface stably, and then continue to combine with a Cl radical to produce HgCl2, which is easy to be removed.

  2. Adsorption of Ar on planar surfaces studied with a density functional theory

    Science.gov (United States)

    Sartarelli, Salvador A.; Szybisz, Leszek

    2009-11-01

    The adsorption of Ar on planar structureless substrates of alkali metals, alkaline-earth metal Mg, CO2 , and Au was analyzed by applying a density functional formalism which includes a recently proposed effective attractive pair potential conditioned to Ar. It is shown that this approach reproduces the experimental surface tension of the liquid-vapor interface over the entire bulk coexistence curve for temperatures T spanning from the triple point Tt up to the critical point Tc . The wetting properties were studied over the entire range temperatures Tt↔Tc . It was found that Ar wets all the investigated surfaces. The adsorption isotherms for alkali metals exhibit first-order phase transitions. Prewetting lines were resolved even for the less attractive surfaces. In the cases of Mg, CO2 , and Au a continuous growth for T≥Tt was obtained. A comparison with experimental data and other microscopic calculations is reported.

  3. Water-clay surface interaction: A neutron scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Sobolev, O., E-mail: sobolev38@gmail.com [LGIT, University of Grenoble and CNRS, BP 53-38041 Grenoble (France); Favre Buivin, F. [HES-SO Fribourg, Bd de Perolles 80-CP 32, CH-1705 Fribourg (Switzerland); Kemner, E.; Russina, M. [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Glienicker Strasse 100, D-14109 Berlin (Germany); Beuneu, B. [Laboratoire Leon Brillouin, C.E. Saclay, 91191 Gif sur Yvette (France); Cuello, G.J. [Institut Laue Langevin and Ikerbasque, 6, rue Jules Horowitz, BP 156, 38042 Grenoble, Cedex 9 (France); Charlet, L. [LGIT, University of Grenoble and CNRS, BP 53-38041 Grenoble (France)

    2010-08-23

    Graphical abstract: Interaction between water molecules and internal clay surfaces was studied by means of neutron diffraction and quasielastic neutron scattering. A hydrophobic cation, TMA{sup +} was used to reduce hydration of interlayer cations. - Abstract: The aim of this study was to investigate interaction between water molecules and internal clay surfaces by means of neutron diffraction and quasielastic neutron scattering. A hydrophobic cation, TMA{sup +} (NC{sub 4}H{sub 12}), was used to saturate the interlayer space of nontronite NAu-1 in order to reduce hydration of interlayer cations that could hinder the effects related to the clay-water interactions. The water content was low in order to reduce hydrogen bonding between water molecules. It was found that water molecules form strong hydrogen bonds with surface oxygen atoms of nontronite. The diffusion activation energy value E{sub a} = 29 {+-} 3 kJ/mol was obtained for water molecules hydrating the clay surface. These results confirm the assumption that surfaces of smectite clays with tetrahedral substitutions are hydrophilic.

  4. A phase I pharmacokinetic study of 21-day continuous infusion mitoxantrone.

    Science.gov (United States)

    Greidanus, J; de Vries, E G; Mulder, N H; Sleijfer, D T; Uges, D R; Oosterhuis, B; Willemse, P H

    1989-06-01

    A phase I study of mitoxantrone given as a continuous infusion for 21 days using a venous access port and a portable pump was performed. The first dose step was 0.3 mg/m2/d for 21 days. Courses were repeated every 6 weeks. Dose increment per step was 0.1 mg/m2/d in the first three dose steps and 0.2 mg/m2/d in the latter dose steps. Twenty-five patients entered the study and received a total of 50 courses, with a median of two courses (range, one to five). Up to 0.5 mg/m2/d, no toxicity (according to the World Health Organization [WHO] criteria) occurred. At 0.7 mg/m2/d, one patient experienced grade 2 leukocytopenia and at the 0.9 mg/m2/d dose step, one patient experienced grade 2 leukocytopenia, grade 1 thrombocytopenia, and grade 1 hair loss. At 1.1 mg/m2/d, two of six patients had grade 3 leukocytopenia, and in one patient treatment was discontinued after two days because of myocardial infarction. In both patients receiving 1.3 mg/m2/d, treatment was discontinued after 2 weeks because of grade 3 leukocytopenia. Three patients at the 1.1 mg/m2/d, dose step and two patients at the 1.3 mg/m2/d dose step experienced some nausea in the last week of the infusion period. One patient developed subclavian vein thrombosis. No infectious complications occurred. Pharmacokinetic studies were performed by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Plasma steady-state was reached after 35 hours. During steady-state there was a linear relationship between the mitoxantrone dose administered and the level of mitoxantrone in plasma (r = .93, P less than .005). The mitoxantrone level in leukocytes increased significantly during the infusion period at the 0.9 mg/m2, the 1.1 mg/m2, and the 1.3 mg/m2 dose steps. The area under the curve (AUC) in leukocytes was higher with continuous infusion of 1.1 mg/m2/d for 21 days compared with bolus injection of 12 mg/m2. Mitoxantrone could be detected in plasma for at least five days after the end of the 21

  5. Study of surface modification of uranium and UFe{sub 2} by various surface analysis techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bonino, O.; Dugne, O.; Merlet, C. E-mail: merlet@dstu.univ-montp2.fr; Gat, E.; Holliger, Ph.; Lahaye, M

    2001-04-01

    The surface modification of U, UFe{sub 2} by exposition in air at room temperature and at 63 deg. C was studied by secondary ion mass spectroscopy (SIMS), time of flight-secondary ion mass spectroscopy (ToF-SIMS), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) with variable detection angle. For the two systems, a first layer of carbon contamination, followed by complex oxide layer constitutes the surface. For U, the oxide layer is composed of a mixture of UO{sub 2} and UO{sub 2+x} with x maximal at the surface. In UFe{sub 2}, the oxide layer is composed of a mixture of UO{sub 2} and UO{sub 2+x}, oxidised iron in Fe2+ and Fe3+ chemical states (more probably FeO), a few percent of a ternary oxide UFeO{sub 4}, and less than 1% of uranium carbide. A surface segregation of uranium is shown in UFe{sub 2}.

  6. The Inquiring Mind: A Study of the Adult Who Continues To Learn. Second Edition.

    Science.gov (United States)

    Houle, Cyril O.

    This book is the second edition of a work drawn from a series of lectures given by a distinguished scholar and teacher in the field of adult learning at the University of Wisconsin in 1960. The subject of the lectures was adult continuing education--who continues to learn and why. Research was conducted through a series of 2-hour interviews with…

  7. A Comparative Study on the Practice of Continuous Assessment between Addis Ababa and Unity Universities

    Science.gov (United States)

    Zeleke, Aytaged Sisay

    2013-01-01

    This paper aims to explore the practice of continuous assessment at Unity University College and Addis Ababa University. It has also investigated constraints instructors say they have been facing in implementing continuous assessment. Students' attitudes about the practice of this assessment mode towards their course achievements were explored.…

  8. Using Dentistry as a Case Study to Examine Continuing Education and Its Impact on Practice

    Science.gov (United States)

    Bullock, Alison; Firmstone, Vickie; Frame, John; Thomas, Hywel

    2010-01-01

    Continuing education is a defining characteristic of work in the professions. Yet the approach various professional groups take to continuing professional development (CPD) differs widely in terms of regulatory frameworks and requirements, modes of delivery and funding. Importantly, little is understood about how CPD impacts on practice. This…

  9. Online Learning Experiences of New versus Continuing Learners: A Large-Scale Replication Study

    Science.gov (United States)

    Li, Nai; Marsh, Vicky; Rienties, Bart; Whitelock, Denise

    2017-01-01

    A vast body of research has indicated the importance of distinguishing new vs. continuing students' learning experiences in blended and online environments. Continuing learners may have developed learning and coping mechanisms for "surviving" in such learning environments, while new learners might still need to adjust their learning…

  10. Online Learning Experiences of New versus Continuing Learners: A Large-Scale Replication Study

    Science.gov (United States)

    Li, Nai; Marsh, Vicky; Rienties, Bart; Whitelock, Denise

    2017-01-01

    A vast body of research has indicated the importance of distinguishing new vs. continuing students' learning experiences in blended and online environments. Continuing learners may have developed learning and coping mechanisms for "surviving" in such learning environments, while new learners might still need to adjust their learning…

  11. A 3-D Computational Study of a Variable Camber Continuous Trailing Edge Flap (VCCTEF) Spanwise Segment

    Science.gov (United States)

    Kaul, Upender K.; Nguyen, Nhan T.

    2015-01-01

    Results of a computational study carried out to explore the effects of various elastomer configurations joining spanwise contiguous Variable Camber Continuous Trailing Edge Flap (VCCTEF) segments are reported here. This research is carried out as a proof-of-concept study that will seek to push the flight envelope in cruise with drag optimization as the objective. The cruise conditions can be well off design such as caused by environmental conditions, maneuvering, etc. To handle these off-design conditions, flap deflection is used so when the flap is deflected in a given direction, the aircraft angle of attack changes accordingly to maintain a given lift. The angle of attack is also a design parameter along with the flap deflection. In a previous 2D study,1 the effect of camber was investigated and the results revealed some insight into the relative merit of various camber settings of the VCCTEF. The present state of the art has not advanced sufficiently to do a full 3-D viscous analysis of the whole NASA Generic Transport Model (GTM) wing with VCCTEF deployed with elastomers. Therefore, this study seeks to explore the local effects of three contiguous flap segments on lift and drag of a model devised here to determine possible trades among various flap deflections to achieve desired lift and drag results. Although this approach is an approximation, it provides new insights into the "local" effects of the relative deflections of the contiguous spanwise flap systems and various elastomer segment configurations. The present study is a natural extension of the 2-D study to assess these local 3-D effects. Design cruise condition at 36,000 feet at free stream Mach number of 0.797 and a mean aerodynamic chord (MAC) based Reynolds number of 30.734x10(exp 6) is simulated for an angle of attack (AoA) range of 0 to 6 deg. In the previous 2-D study, the calculations revealed that the parabolic arc camber (1x2x3) and circular arc camber (VCCTEF222) offered the best L

  12. Kinetic-energy functionals studied by surface calculations

    DEFF Research Database (Denmark)

    Vitos, Levente; Skriver, Hans Lomholt; Kollár, J.

    1998-01-01

    The self-consistent jellium model of metal surfaces is used to study the accuracy of a number of semilocal kinetic-energy functionals for independent particles. It is shown that the poor accuracy exhibited by the gradient expansion approximation and most of the semiempirical functionals in the low...

  13. Studying surface glow discharge for application in plasma aerodynamics

    Science.gov (United States)

    Tereshonok, D. V.

    2014-02-01

    Surface glow discharge in nitrogen between two infinite planar electrodes occurring on the same plane has been studied in the framework of a diffusion-drift model. Based on the results of numerical simulations, the plasma structure of this discharge is analyzed and the possibility of using it in plasma aerodynamics is considered.

  14. Localization of optical excitations on random surfaces: SNOM studies

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.

    1999-01-01

    Localization of optical excitations on nanostructured metal surfaces and fractal colloid silver aggregates are studied by using a scanning near-field optical microscope (SNOM). The SNOM images obtained in both configurations exhibit spatially localized (within 150 to 250 nm) light intensity...

  15. Theoretical study of n-alkane adsorption on metal surfaces

    DEFF Research Database (Denmark)

    Morikawa, Yoshitada; Ishii, Hisao; Seki, Kazuhiko

    2004-01-01

    The interaction between n-alkane and metal surfaces has been studied by means of density-functional theoretical calculations within a generalized gradient approximation (GGA). We demonstrate that although the GGA cannot reproduce the physisorption energy well, our calculations can reproduce the e...

  16. Comparative study of isomalt and sucrose by means of continuous indirect calorimetry.

    Science.gov (United States)

    Thiébaud, D; Jacot, E; Schmitz, H; Spengler, M; Felber, J P

    1984-09-01

    Isomalt (Palatinit) an equimolar mixture of alpha-D-glucopyranosido-1,6-sorbitol and alpha-D-glucopyranosido-1,6-mannitol, was compared to sucrose in a prospective double-blind controlled crossover study. The acute effects of oral ingestion of 30-g loads of isomalt or sucrose on plasma glucose, insulin, free fatty acids (FFA), lactic acid, and carbohydrate (CHO) and lipid oxidation were studied over six hours by means of continuous indirect calorimetry in ten healthy normal-weight subjects. Unlike sucrose, whose ingestion was followed by significant changes in plasma glucose, insulin, and lactic acid during the first 60 minutes of the test, no significant changes in these parameters were observed following the administration of isomalt. The increase in CHO oxidation occurring between 30 and 150 minutes was significantly lower (P less than 0.01) following isomalt than after sucrose. Conversely, the decrease in lipid oxidation was significantly less (P less than 0.01) after isomalt in comparison to sucrose. It is concluded that the rise in CHO oxidation and in plasma glucose and insulin levels is markedly reduced when sucrose is replaced by an equal weight of isomalt. In contrast to other sugar substitutes, no increase in plasma lactic acid was observed after isomalt administration.

  17. Pseudo-continuous arterial spin labeling MRI study of schizophrenic patients.

    Science.gov (United States)

    Ota, Miho; Ishikawa, Masanori; Sato, Noriko; Okazaki, Mitsutoshi; Maikusa, Norihide; Hori, Hiroaki; Hattori, Kotaro; Teraishi, Toshiya; Ito, Kimiteru; Kunugi, Hiroshi

    2014-04-01

    Arterial spin labeling (ASL) magnetic resonance imaging (MRI) is a novel noninvasive technique that can measure regional cerebral blood flow (rCBF). To our knowledge, few studies have examined rCBF in patients with schizophrenia by ASL-MRI. Here we used pseudo-continuous ASL (pCASL) to examine the structural and functional imaging data in schizophrenic patients, taking the regional cerebral gray matter volume into account. The subjects were 36 patients with schizophrenia and 42 healthy volunteers who underwent 3-tesla MRI, diffusion tensor imaging (DTI), and pCASL. We evaluated the gray matter volume imaging, DTI, and pCASL imaging data in a voxel-by-voxel statistical analysis. The schizophrenia patients showed reduced rCBF in the left prefrontal and bilateral occipital cortices compared to the healthy volunteers. There was a significant reduction of gray matter volume in the left inferior frontal cortex in the schizophrenia patients. With respect to the fractional anisotropy (FA) values in the DTI, there were significant FA reductions in the left superior temporal, left external capsule, and left inferior prefrontal regions in the patients compared to the controls. Our pCASL study with partial volume effect correction together with volumetry and DTI data demonstrated hypoactivity in the left prefrontal area beyond structural abnormalities in schizophrenia patients. There were also hypofunction areas in bilateral occipital cortices, although structural abnormalities were not apparent. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Reservoir Simulation on the Cerro Prieto Geothermal Field: A Continuing Study

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, M.; Marquez, R.; Arellano, V.; Esquer, C.A.

    1983-12-15

    The Cerro Prieto geothermal field is a liquid-dominated geothermal reservoir of complex geological and hydrological structure. It is located at the southern end of the Salton-Mexicali trough which includes other geothermal anomalies as Heber and East Mesa. Although in 1973, the initial power plant installed capacity was 75 MW of electrical power, this amount increased to 180 MW in 1981 as field development continued. It is expected to have a generating capacity of 620 MW by the end of 1985, when two new plants will be completely in operation. Questions about field deliverability, reservoir life and ultimate recovery related to planned installations are being presently asked. Numerical modeling studies can give very valuable answers to these questions, even at the early stages in the development of a field. An effort to simulate the Cerro Prieto geothermal reservoir has been undergoing for almost two years. A joint project among Comision Federal de Electricidad (CFE), Instituto de Investigaciones Electricas (IIE) and Intercomp of Houstin, Texas, was created to perform reservoir engineering and simulation studies on this field. The final project objective is tosimulate the behavior of the old field region when production from additional wells located in the undeveloped field zones will be used for feeding the new power plants.

  19. Single incision laparoscopic TAPP with standard laparoscopic instruments and suturing of flaps: A continuing study

    Directory of Open Access Journals (Sweden)

    Rajeev Sinha

    2015-01-01

    Full Text Available Background: Single incision laparoscopic surgery, especially transumbilical, should be the closest to replicate the minimal access results achieved by natural orifice endoscopic surgery (NOTES. This study of single incision transabdominal preperitoneal (SITAPP inguinal hernia repair is a continuing study exploring the peroperative variables and short and long term complications of this procedure. Patients and Methods: All the 183 patients were operated by the same surgeon through a horizontal transumbilical incision positioned across the lower third of the umbilicus. Port access was through three separate transfacial punctures. Routine rigid instruments were used and the peritoneal flaps were either tacked or sutured into place. Patients with irreducible hernia and obstructed hernia were included, while those with strangulated hernia were excluded. Results: All the patients were male with an average age of 41.4 years. Twenty four patients had bilateral hernia, 15 patients had irreducible and 6 patients had obstructed hernia. The mean operating time was 38.3 mins for unilateral hernias completed with tackers and 42.8 mins in those with intracorporeal suturing. The corresponding operating time for bilateral hernias was 53.2 and 62.7 minutes. There was minimal serous discharge from the umbilicus in 8 patients, port site infection in 1 patient and recurrence in 2 patients over a 36 months period. Conclusions: SITAPP for groin hernias, performed with conventional instruments is feasible, easy to learn, has a very high patient acceptance and is cosmetically superior to conventional TAPP. The use of tackers reduces the operating time significantly.

  20. Numerical study of steady turbulent flow through bifurcated nozzles in continuous casting

    Science.gov (United States)

    Najjar, Fady M.; Thomas, Brian G.; Hershey, Donald E.

    1995-08-01

    Bifurcated nozzles are used in continuous casting of molten steel, where they influence the quality of the cast steel slabs. The present study performs two-dimensional (2-D) and three-dimensional (3-D) simulations of steady turbulent (K- ɛ) flow in bifurcated nozzles, using a finite-element (FIDAP) model, which has been verified previously with water model experiments. The effects of nozzle design and casting process operating variables on the jet characteristics exiting the nozzle are investigated. The nozzle design parameters studied include the shape, angle, height, width, and thickness of the ports and the bottom geometry. The process operating practices include inlet velocity profile and angle as well as port curvature caused by erosion or inclusion buildup. Results show that the jet angle is controlled mainly by the port angle but is steeper with larger port area and thinner walls. The degree of swirl is increased by larger or rounder ports. The effective port area, where there is no recirculation, is increased by smaller or curved ports. Flow asymmetry is more severe with skewed or angled inlet conditions or unequal port sizes. Turbulence levels in the jet are higher with higher casting speed and smaller ports.

  1. Impact of microcrystalline cellulose material attributes: a case study on continuous twin screw granulation.

    Science.gov (United States)

    Fonteyne, Margot; Correia, Ana; De Plecker, Sofie; Vercruysse, Jurgen; Ilić, Ilija; Zhou, Qi; Vervaet, Chris; Remon, Jean Paul; Onofre, Fernanda; Bulone, Vincent; De Beer, Thomas

    2015-01-30

    The International Conference on Harmonisation (ICH) states in its Q8 'Pharmaceutical Development' guideline that the manufacturer of pharmaceuticals should have an enhanced knowledge of the product performance over a range of material attributes, manufacturing process options and process parameters. The present case study evaluates the effect of unspecified variability of raw material properties upon the quality attributes of granules; produced using a continuous from-powder-to-tablet wet granulation line (ConsiGma™ 25). The impact of different material attributes of six samples of microcrystalline cellulose (MCC) was investigated. During a blind study the different samples of MCC were used separately and the resulting granules were evaluated in order to identify the differences between the six samples. Variation in size distribution due to varying water binding capacity of the MCC samples was observed. The cause of this different water binding capacity was investigated and was caused by a different degree of crystallinity. Afterwards, an experimental design was conducted in order to evaluate the effect of both product and process variability upon the granule size distribution. This model was used in order to calculate the required process parameters to obtain a preset granule size distribution regardless of the type of MCC used. The difference in water binding capacity and its effect on granular properties was still present when combining the MCC grades with different binders. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Determination of 2-propanol in surface cleaning solutions used for copper continuous casting process by flow injection-spectrophotometric detection with on-line column separation.

    Science.gov (United States)

    Hayashibe, Yutaka; Tokuda, Masahiro; Takeya, Minoru

    2003-09-01

    A flow-injection system has been developed for the determination of 2-propanol in the surface cleaning solutions used in the copper continuous cast rod making system. Adsorption chromatography in nitric acid medium was used for the on-line separation of oily substances in the sample solution. Cerium(IV) diammonium nitrate was utilized as the chromogenic reagent for the spectrophotometric detection of 2-propanol. The system permits a throughput of one sample per hour for the oily sample, and of 12 samples per hour for the none-oily sample. The reproducibility has been proven to be satisfactory with a relative standard deviation of less than 6.0% (2.2%(V/V) 2-propanol level, n = 23). The detection limit is 0.01% (V/V).

  3. Frequency-modulated continuous-wave laser radar using dual vertical-cavity surface-emitting laser diodes for real-time measurements of distance and radial velocity

    Science.gov (United States)

    Kakuma, Seiichi

    2017-02-01

    A frequency-modulated continuous-wave (FMCW) laser radar capable of real-time displaying the distance to a target object and its radial velocity as their corresponding frequency spectra is developed. The system employs a pair of oppositely frequency-swept vertical-cavity surface-emitting laser diodes (VCSELs). This makes possible simultaneous detection of beat signals induced by the increment (up-ramp) and decrement (down-ramp) in laser frequencies. By mixing these two beat signals, their sum and difference frequencies are directly obtained without arithmetic processing such as averaging and subtraction. Results of the test experiments adopting axially moving block gauges as target objects show that both the distance and given velocities are accurately determined from the spectrum of the frequency mixer.

  4. Studies of surface diffusion by second harmonic fluctuation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiaolin; Goh, M.C.; Subrahmanyan, S.; Eisenthal, K.B. (Columbia Univ., New York, NY (USA))

    1990-05-03

    The authors have shown how the fluctuations in the signal from surface second harmonic generation can be utilized for the study of a heterogeneous surface such as palmitic acid (C{sub 15}H{sub 31}COOH) spread on the air/water interface, under conditions of gas-liquid coexistence. The authors report observations of time-correlated fluctuations in the SH signal, with decay constant of approximately 6 s. This is attributed to motions of the liquidlike clusters of palmitic acid. If the motion is diffusive, a diffusion constant of about 10{sup {minus}8} cm{sup 2}/s is estimated for these clusters.

  5. Study on the Surface Property of Surfactant Ionic Liquids Solutions

    Institute of Scientific and Technical Information of China (English)

    Yan An GAO; Zhong Ni WANG; Jin ZHANG; Wan Guo HOU; Gan Zuo LI; Bu Xing HAN; Feng Feng Lü; Gao Yong ZHANG

    2005-01-01

    The surfactant TX-100 can be dissolved in ionic liquid bmimPF6 and decrease the surface tension of 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6) solutions. Here,we confirmed that in this new system, the pure solvents need rearrangement at the air-water interface at the initial stage. The dynamic surface tension (DST) study shows that at the initial adsorption stage, the adsorption model of surfactant accords with the diffusion-controlled adsorption mechanism, and the dilute ionic liquids solutions is further close to the diffusion-controlled adsorption.

  6. Laboratory Study of Dispersion of Buoyant Surface Plumes

    DEFF Research Database (Denmark)

    Petersen, Ole; Larsen, Torben

    1990-01-01

    A laboratory a study on surface dispersion of buoyant plumes in open channel turbulence in made, where the buoyancy is due to both salinity and heat. The measured parameters are the downstream derivative of a plume width and height, which are integral-characteristics of the distributions of density......-differences. Other methods as infra-red sensing are used for visualizing purpose. The results are used to calibrate an integral model of the dispersion. Conclusions are that the dispersion of a buoyant surface plume can be treated the superposition of a buoyancy induced stretching and turbulent diffusion, reduced...

  7. Continuous Production of Lipase-Catalyzed Biodiesel in a Packed-Bed Reactor: Optimization and Enzyme Reuse Study

    OpenAIRE

    Hsiao-Ching Chen; Hen-Yi Ju; Tsung-Ta Wu; Yung-Chuan Liu; Chih-Chen Lee; Cheng Chang; Yi-Lin Chung; Chwen-Jen Shieh

    2010-01-01

    An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in a tert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature have significant effects on the percentage of mol...

  8. Continuing medical education revisited: theoretical assumptions and practical implications: a qualitative study.

    Science.gov (United States)

    Dionyssopoulos, Alexander; Karalis, Thanassis; Panitsides, Eugenia A

    2014-12-31

    Recent research has evidenced that although investment in Continuing Medical Education (CME), both in terms of participation as well as financial resources allocated to it, has been steadily increasing to catch up with accelerating advances in health information and technology, effectiveness of CME is reported to be rather limited. Poor and disproportional returns can be attributed to failure of CME courses to address and stimulate an adult audience. The present study initially drew on research findings and adult learning theories, providing the basis for comprehending adult learning, while entailing practical implications on fostering effectiveness in the design and delivery of CME. On a second level, a qualitative study was conducted with the aim to elucidate parameters accounting for effectiveness in educational interventions. Qualitative data was retrieved through 12 in-depth interviews, conducted with a random sample of participants in the 26th European Workshop of Advanced Plastic Surgery (EWAPS). The data underwent a three level qualitative analysis, following the "grounded theory" methodology, comprising 'open coding', 'axial coding' and 'selective coding'. Findings from the EWAPS study come in line with relevant literature, entailing significant implications for the necessity to apply a more effective and efficient paradigm in the design and delivery of educational interventions, advocating for implementing learner-centered schemata in CME and benefiting from a model that draws on the learning environment and social aspects of learning. What emerged as a pivotal parameter in designing educational interventions is to focus on small group educational events which could provide a supportive friendly context, enhance motivation through learner-centered approaches and allow interaction, experimentation and critical reflection. It should be outlined however that further research is required as the present study is limited in scope, having dealt with a limited

  9. Archaeomagnetic study of ancient slag mounds in Cyprus: continuous paleointensity curves in high resolution

    Science.gov (United States)

    Shaar, R.; Tauxe, L.; Ben-Yosef, E.; Levy, T. E.; Kassianidou, V.; Lorentzen, B. E.

    2012-12-01

    One of the main challenges in paleointensity research is obtaining continuous high-resolution records that describe the behavior of the geomagnetic field on short time scales. One difficulty in obtaining such records is the problem of precise dating of suitable samples. Another fundamental difficulty is the assessment of the uncertainty involved in the interpretation of paleointensity experiments. Here we present an archaeomagnetic study of ancient slag mounds, which is designed to minimize these difficulties. We study two archaeological slag mounds in the Troodos foothills of Cyprus; one from the massive Roman mines at Skouriotissa, and another pre Roman near Mitsero Kokkinoyia. The mounds consist of industrial layers of copper slag intermixed with charcoal, which were deposited during times of intense copper smelting activity. The slag mound at Skouriotissa represents one of the largest copper production sites in the ancient world, including a 25 m high section and more than 40 archaeological layers. The mound at Mitsero is ca. 10 m high and contains about 32 layers. Hundreds of slag samples and associated charcoals from both mounds were collected, from which more than 600 slag specimens from more than 150 individual samples were analyzed for paleointensity. In addition,19 charcoals were radiocarbon dated. To minimize the uncertainty in the radiocarbon dating we applied a Bayesian model for each mound, which takes into account the relative stratigraphy of the layers. To reduce the uncertainty involved in the subjective interpretation of the paleointensity experiments (conventionally done by manually selecting temperature bounds in the Arai plot of each specimen) we designed new optimization software. The optimization software uses the assumption that paleointensity estimates from samples that were collected from the same level, should be similar. The optimization algorithm finds the selecting criteria that yields minimum scatter within each level, assigns

  10. Linear optical studies of metal surfaces: Diffusion, growth, and surface dynamics

    Science.gov (United States)

    Nabighian, Edward Ara

    Through the use of laser-induced thermal desorption, a monolayer density grating is produced on a Ni(111) substrate. Using linear optical diffraction from this grating we monitor surface diffusion. By varying the angular direction of the grating we also monitor the azimuthal dependence of diffusion over 360° rotation. For hydrogen on Ni(111) we measured the diffusion rates from 65 K to 240 K, yielding diffusion rates which vary from 2 × 10 -15 cm2/sec to 2 × 10-7 cm2/sec. The results reveal energies of diffusion in both the classical overbarrier hopping and phonon-assisted quantum regimes. For xenon on Ni(111) we measured the diffusion rates from 30 K to 60 K, yielding diffusion rates which vary from 1.3 × 10-10 cm2/sec to 1 × 10-9 cm2/sec. In the case of xenon diffusion, the results also reveal an unusually low diffusivity. In addition, growth measurements of xenon on Ni(111) were studied from 35 K to 60 K using an optical reflectance difference technique. The growth of xenon was found to change mechanisms as temperature varied. At 35 K xenon grows in 3-dimensional islands (Volmer-Weber growth), at 40 K xenon grows as 2-dimensional islands (Frank van der Merwe growth), and above 60 K xenon grows to a thickness of only one monolayer. We can not only monitor the growth mechanism, but the growth rate as well. Finally we use optical reflectance difference to monitor sputtering and annealing on the Ni(111) substrate. The competing surface roughening of sputtering and surface reordering of annealing was found to follow an Arrhenius form with an activation energy of Ea = 1.1 eV/atom given by direct atom evaporation from step edges. By monitoring the formation of islands and pits on the surface during sputtering at various temperatures we are able to determine that above 823 K the annealing process reorders the surface faster than sputtering can create surface roughness. As temperature decreases we see an increase in island and pit formation due to the lessened

  11. The study of UHMWPEF surface modification with plasma- induced polymerization

    Science.gov (United States)

    Zhang, Yu-Fang; Jia, Qing-Xiu; Wang, Xin; Zhang, Pei-Ran

    2015-07-01

    In order to improve the surface activity levels of the ultrahigh molecular weight polyethylene fiber (UHMWPEF), as well as enhancing the interface strength of the UHMWPEF based composite materials, the method of plasma-induced polymerization was applied to modify the UHMWPEF surface. In this study, the plasma's power, time, pressure and the grafting monomer concentration were introduced. Also, through a well-conducted comparison and analysis of the grafting rate, fabric surface functional groups and the microcosmic morphology, the most suitable plasma modification process was discovered and determined. The mechanics performance of hybrid composites with the modified UHMWPEF and unidirectional carbon fiber cloth (CF) was tested to reveal that, compared with the unmodified composites, the tensile strength and the laminar shear strength could be improved.

  12. Experimental Study on Plasma Surface Treatment of Capacitors Film

    Science.gov (United States)

    Ling, Dai; Ting, Yin; Fuchang, Lin; Fei, Yan

    Plasma surface treatment is an optional way to change the electrical performance of the film capacitors used widely in pulse power application. This paper presents the experimental study of glow discharge plasma treatment to polyphenylene sulfide (PPS) film. By using infrared spectra and scanning electron microscope (SEM), the chemical component and microstructure of material surface has detected to be changed with different treatment strength and various discharge gas. After treatment, the film surface tends to be rougher and some sorts of polar radicals or groups found to be introduced. But there is no obvious change of the electrical strength of the film. At last, theoretical analysis has been carried out with polypropylene film experimental treatment results in author's former work.

  13. Surface photovoltage studies of nonstoichiometric rutile titanium dioxide

    Science.gov (United States)

    Sheppard, L. R.; Dittrich, T.; Nowotny, J.; Bak, T.

    2010-02-01

    The aim of the present investigation was to assess how processing at elevated temperatures impacts upon the room temperature electronic structure of rutile TiO2. Consequently, strongly reduced and oxidized rutile TiO2 pellets were processed under controlled conditions and studied using surface photovoltage spectroscopy. Under illumination with photon energies above the band gap energy, reduced and oxidized rutile, respectively, displayed positive and negative surface photovoltages. This result indicates that undoped TiO2 may be tailored to promote either photoreduction or photo-oxidation reactions. Several transitions involving surface and bulk electronic states within the band gap were observed in oxidized rutile, but in contrast, similar states could not be readily distinguished in reduced rutile. A band diagram of oxidized rutile is proposed.

  14. Study of surface plasmon chirality induced by Archimedes' spiral grooves.

    Science.gov (United States)

    Ohno, Tomoki; Miyanishi, Shintaro

    2006-06-26

    A chirality of surface plasmons excited on a silver film with Archimedes' spiral grooves during incidence of a circularly polarized light is analytically and numerically studied by using the finite-difference time-domain (FDTD) modeling method. We found that the surface of a plasmon has selective chirality, which is given by the sum of the chiralities of the incident light and the spiral structure. The surface plasmons with the chirality lead to zero-order, first-order, and high-order evanescent Bessel beams with electric charge distributions on the film. This selectivity could be widely applied for chiral detection of the incident light and chiral excitation of several optical modes in nanophotonics.

  15. Analytical study of surface states caused by the edge decoration

    Institute of Scientific and Technical Information of China (English)

    Zhao Yuan-Yuan; Li Wei; Tao Rui-Bao

    2012-01-01

    Analytical studies of the effect of edge decoration on the energy spectrum of semi-infinite one-dimensional (1D) model and zigzag edged graphene (ZEG) are presented by means of transfer matrix method,in the frame of which the conditions for the existence of edge states are determined.For 1D model,the zero-energy surface state occurs regardless of whether the decorations exist or not,while the non-zero-energy surface states can be induced and manipulated through adjusting the edge decoration.On the other hand,the case for the semi-infinite ZEG model with nearestneighbour interaction is discussed in the analogous way.The non-zero-energy surface states can be induced by the edge decoration and moreover,the ratio between the edge hopping and the bulk hopping amplitudes should be within a certain threshold.

  16. STUDY OF SURFACE PHENOMENA IN MATERIALS OF PROSTHETIC RESTORATION

    Directory of Open Access Journals (Sweden)

    Mihaela-Păpuşa Vasiliu

    2012-12-01

    Full Text Available As a direct consequence of their application domain – the oral cavity – dental materials are subjected to the corosive action of saliva, being surrounded by microorganisms, fluids and alimentary rests, which modify their surface characteristics. Concerns on the quality of the dental materials explain the numeorus interdisciplinary studies, characterized by a close relation among various scientific domains (physics, chemistry, biology, science of biomaterials, techniques also applied in clinical stomatology. Analysis of the saliva–dental materials interface made use of ceramic surfaces, composites and artificial saliva, permitting to determine the main surface parameters of the materials of prosthetic restoration, calculated with some physical models, starting from measurements of the contact angle: surface energy, its polar and dispersive components, surface rugosity, adhesion mechanic work. All composites showed low values of the adhesion mechanic work, the conclusion being that they are much more hydrophobic than the ceramic materials. Such a property is especially important from an aesthetic perspective, as the hydrophobic materials have a better colour stability in time.

  17. CFD study of turbulent jet impingement on curved surface

    Institute of Scientific and Technical Information of China (English)

    Javad Taghinia; Md Mizanur Rahman; Timo Siikonen

    2016-01-01

    The heat transfer and flow characteristics of air jet impingement on a curved surface are investigated with com-putational fluid dynamics (CFD) approach. The first applied model is a one-equation SGS model for large eddy simulation (LES) and the second one is the SST-SAS hybrid RANS-LES. These models are utilized to study the flow physics in impinging process on a curved surface for different jet-to-surface (h/B) distances at two Reynolds numbers namely, 2960 and 4740 based on the jet exit velocity (Ue) and the hydraulic diameter (2B). The predic-tions are compared with the experimental data in the literature and also the results from RANS k-εmodel. Com-parisons show that both models can produce relatively good results. However, one-equation model (OEM) produced more accurate results especial y at impingement region at lower jet-to-surface distances. In terms of heat transfer, the OEM also predicted better at different jet-to-surface spacings. It is also observed that both models show similar performance at higher h/B ratios.

  18. Localization of a continuous CO2 leak from an isotropic flat-surface structure using acoustic emission detection and near-field beamforming techniques

    Science.gov (United States)

    Yan, Yong; Cui, Xiwang; Guo, Miao; Han, Xiaojuan

    2016-11-01

    Seal capacity is of great importance for the safety operation of pressurized vessels. It is crucial to locate the leak hole timely and accurately for reasons of safety and maintenance. This paper presents the principle and application of a linear acoustic emission sensor array and a near-field beamforming technique to identify the location of a continuous CO2 leak from an isotropic flat-surface structure on a pressurized vessel in the carbon capture and storage system. Acoustic signals generated by the leak hole are collected using a linear high-frequency sensor array. Time-frequency analysis and a narrow-band filtering technique are deployed to extract effective information about the leak. The impacts of various factors on the performance of the localization technique are simulated, compared and discussed, including the number of sensors, distance between the leak hole and sensor array and spacing between adjacent sensors. Experiments were carried out on a laboratory-scale test rig to assess the effectiveness and operability of the proposed method. The results obtained suggest that the proposed method is capable of providing accurate and reliable localization of a continuous CO2 leak.

  19. First Principles Studies of ABO3 Perovskite Surfaces and Nanostructures

    Science.gov (United States)

    Pilania, Ghanshyam

    Perovskite-type complex oxides, with general formula ABO 3, constitute one of the most prominent classes of metal oxides which finds key applications in diverse technological fields. In recent years, properties of perovskites at reduced dimensions have aroused considerable interest. However, a complete atomic-level understanding of various phenomena is yet to emerge. To fully exploit the materials opportunities provided by nano-structured perovskites, it is important to characterize and understand their bulk and near-surface electronic structure along with the electric, magnetic, elastic and chemical properties of these materials in the nano-regime, where surface and interface effects naturally play a dominant role. In this thesis, state-of-the-art first principles computations are employed to systematically study properties of one- and two-dimensional perovskite systems which are of direct technological significance. Specifically, our bifocal study targets (1) polarization behavior and dielectric response of ABO3 ferroelectric nanowires, and (2) oxygen chemistry relevant for catalytic properties of ABO3 surfaces. In the first strand, we identify presence of novel closure or vortex-like polarization domains in PbTIO3 and BaTiO3 ferroelectric nanowires and explore ways to control the polarization configurations by means of strain and surface chemistry in these prototypical model systems. The intrinsic tendency towards vortex polarization at reduced dimensions and the underlying driving forces are discussed and previously unknown strain induced phase transitions are identified. Furthermore, to compute the dielectric permittivity of nanostructures, a new multiscale model is developed and applied to the PbTiO3 nanowires with conventional and vortex-like polarization configurations. The second part of the work undertaken in this thesis is comprised of a number of ab initio surface studies, targeted to investigate the effects of surface terminations, prevailing chemical

  20. A Study of the Microstructure and Mechanical Properties of Continuously Cast Iron Products

    Directory of Open Access Journals (Sweden)

    Bockus, S.

    2006-01-01

    Full Text Available The horizontal continuous casting has a lot of advantages in comparison with traditional casting methods. But it has a few disadvantages and unsolved problems. The objective of this research was the experimental investigation of the effect of chemical composition of cast iron and the casting conditions on the microstructure and properties of continuously cast ingots. As a result, tensile strength, Brinell hardness, and pearlite content increased with increasing Cr, Cu, and Sb additions and decreasing carbon equivalent. As for microstructure of graphite, higher silicon to carbon ratio and lower solidification rate decreased a zone of interdendritic graphite. Nomograph of continuously cast iron structure was made.

  1. Surface chemical study on the covalent attachment of hydroxypropyltrimethyl ammonium chloride chitosan to titanium surfaces

    Science.gov (United States)

    Xu, Xiaofen; Wang, Ling; Guo, Shengrong; Lei, Lei; Tang, Tingting

    2011-10-01

    An anti-microbial and bioactive coating could not only reduce the probability of infection related to titanium implants but also support the growth of surrounding osteogenic cells. Our previous study has showed that hydroxypropyltrimethyl ammonium chloride chitosan (HACC) with a DS (degrees of substitution) of 18% had improved solubility and significantly higher antibacterial activities against three bacteria which were usually associated with infections in orthopaedics. In the current study, HACC with a DS of 18% coating was bonded to titanium surface by a three-step process. The titanium surface after each individual reaction step was analyzed by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection (ATR) of Fourier-transformed infrared (FT-IR) spectroscopy. The XPS results demonstrated that there were great changes in the atomic ratios of C/Ti, O/Ti, and N/Ti after each reaction step. The XPS high resolution and corresponding devolution spectra of carbon, oxygen, nitrogen, and titanium were also in good coordination with the anticipated reaction steps. Additionally, the absorption bands around 3365 cm -1 (-OH vibration), 1664 cm -1 (Amide I), 1165 cm -1 ( νas, C-O-C bridge), and the broad absorption bands between 958 cm -1 and 1155 cm -1 (skeletal vibrations involving the C-O stretching of saccharide structure of HACC) verified that HACC was successfully attached to titanium surface.

  2. Surface chemical study on the covalent attachment of hydroxypropyltrimethyl ammonium chloride chitosan to titanium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Xu Xiaofen; Wang Ling [School of Pharmacy, Shanghai Jiao Tong University, 800 Dong-chuan Road, Shanghai 200240 (China); Guo Shengrong, E-mail: srguo@sjtu.edu.cn [School of Pharmacy, Shanghai Jiao Tong University, 800 Dong-chuan Road, Shanghai 200240 (China); Lei Lei [School of Pharmacy, Shanghai Jiao Tong University, 800 Dong-chuan Road, Shanghai 200240 (China); Tang Tingting, E-mail: tingtingtang@hotmail.com [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiaotong University School of Medicine (China)

    2011-10-01

    An anti-microbial and bioactive coating could not only reduce the probability of infection related to titanium implants but also support the growth of surrounding osteogenic cells. Our previous study has showed that hydroxypropyltrimethyl ammonium chloride chitosan (HACC) with a DS (degrees of substitution) of 18% had improved solubility and significantly higher antibacterial activities against three bacteria which were usually associated with infections in orthopaedics. In the current study, HACC with a DS of 18% coating was bonded to titanium surface by a three-step process. The titanium surface after each individual reaction step was analyzed by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection (ATR) of Fourier-transformed infrared (FT-IR) spectroscopy. The XPS results demonstrated that there were great changes in the atomic ratios of C/Ti, O/Ti, and N/Ti after each reaction step. The XPS high resolution and corresponding devolution spectra of carbon, oxygen, nitrogen, and titanium were also in good coordination with the anticipated reaction steps. Additionally, the absorption bands around 3365 cm{sup -1} (-OH vibration), 1664 cm{sup -1} (Amide I), 1165 cm{sup -1} ({nu}{sub as}, C-O-C bridge), and the broad absorption bands between 958 cm{sup -1} and 1155 cm{sup -1} (skeletal vibrations involving the C-O stretching of saccharide structure of HACC) verified that HACC was successfully attached to titanium surface.

  3. Nutritional status and clinical outcome of children on continuous renal replacement therapy: a prospective observational study

    Directory of Open Access Journals (Sweden)

    Castillo Ana

    2012-09-01

    Full Text Available Abstract Background No studies on continuous renal replacement therapy (CRRT have analyzed nutritional status in children. The objective of this study was to assess the association between mortality and nutritional status of children receiving CRRT. Methods Prospective observational study to analyze the nutritional status of children receiving CRRT and its association with mortality. The variables recorded were age, weight, sex, diagnosis, albumin, creatinine, urea, uric acid, severity of illness scores, CRRT-related complications, duration of admission to the pediatric intensive care unit, and mortality. Results The sample comprised 174 critically ill children on CRRT. The median weight of the patients was 10 kg, 35% were under percentile (P 3, and 56% had a weight/P50 ratio of less than 0.85. Only two patients were above P95. The mean age for patients under P3 was significantly lower than that of the other patients (p = 0.03. The incidence of weight under P3 was greater in younger children (p = 0.007 and in cardiac patients and in those who had previous chronic renal insufficiency (p = 0.047. The mortality analysis did not include patients with pre-existing renal disease. Mortality was 38.9%. Mortality for patients with weight P3 (51% vs 33%; p = 0.037. In the univariate and multivariate logistic regression analyses, the only factor associated with mortality was protein-energy wasting (malnutrition (OR, 2.11; 95% CI, 1.067-4.173; p = 0.032. Conclusions The frequency of protein-energy wasting in children who require CRRT is high, and the frequency of obesity is low. Protein-energy wasting is more frequent in children with previous end-stage renal disease and heart disease. Underweight children present a higher mortality rate than patients with normal body weight.

  4. Continuous quality improvement in daily clinical practice: a proof of concept study.

    Directory of Open Access Journals (Sweden)

    Jonathan A Lorch

    Full Text Available Continuous Quality Improvement (CQI is an iterative process of: planning to improve a product or process, plan implementation, analyzing and comparing results against those expected, and corrective action on differences between actual and expected results. It is little used in clinical medicine. Anemia, a complex problem in End Stage Renal Disease patients, served to test the ability of an unique electronic medical record (EMR optimized for daily care to empower CQI in practice. We used data collected during daily care, stored in the EMR, and organized to display temporal relationships between clinical, laboratory, and therapeutic events. Our aims were optimal hemoglobin with minimum epoetin, and maintaining stable hemoglobin and epoetin. The study was done on 250 patients treated by maintenance hemodialysis (HD, receiving epoetin prior to February 1, 2010 and followed to July 31, 2011. Repleting iron, ensuring iron sufficiency, slow epoetin reduction, and decision support tools enabling data display over long periods in patient-centered reports were key elements. Epoetin dose, adjusted 6-8 weekly, was based on current clinical conditions and past responses. Hemoglobin increased by months 1-2; epoetin decreased from month 4. By months 16-18, epoetin had decreased 42% to 9,720 units/week while hemoglobin increased 8% to 123.6 g/L. Hemoglobin and epoetin were stable from month 7 onward. New epoetin orders decreased 83%. Transferrin saturation increased after the study start. Individual patient hemoglobin variation decreased by 23%, range by 27%. Mortality, 11.78 per 100 patient years, was 42% less than United States dialysis patient mortality. Allowable epoetin charges decreased by $15.33 per treatment and were $22.88 less than current Medicare allowance. The study validates the hypothesis that an EMR optimized for daily patient care can empower CQI in clinical medicine and serve to monitor medical care quality and cost.

  5. Speed of processing in the primary motor cortex: a continuous theta burst stimulation study.

    Science.gov (United States)

    Lakhani, Bimal; Bolton, David A E; Miyasike-Dasilva, Veronica; Vette, Albert H; McIlroy, William E

    2014-03-15

    'Temporally urgent' reactions are extremely rapid, spatially precise movements that are evoked following discrete stimuli. The involvement of primary motor cortex (M1) and its relationship to stimulus intensity in such reactions is not well understood. Continuous theta burst stimulation (cTBS) suppresses focal regions of the cortex and can assess the involvement of motor cortex in speed of processing. The primary objective of this study was to explore the involvement of M1 in speed of processing with respect to stimulus intensity. Thirteen healthy young adults participated in this experiment. Behavioral testing consisted of a simple button press using the index finger following median nerve stimulation of the opposite limb, at either high or low stimulus intensity. Reaction time was measured by the onset of electromyographic activity from the first dorsal interosseous (FDI) muscle of each limb. Participants completed a 30 min bout of behavioral testing prior to, and 15 min following, the delivery of cTBS to the motor cortical representation of the right FDI. The effect of cTBS on motor cortex was measured by recording the average of 30 motor evoked potentials (MEPs) just prior to, and 5 min following, cTBS. Paired t-tests revealed that, of thirteen participants, five demonstrated a significant attenuation, three demonstrated a significant facilitation and five demonstrated no significant change in MEP amplitude following cTBS. Of the group that demonstrated attenuated MEPs, there was a biologically significant interaction between stimulus intensity and effect of cTBS on reaction time and amplitude of muscle activation. This study demonstrates the variability of potential outcomes associated with the use of cTBS and further study on the mechanisms that underscore the methodology is required. Importantly, changes in motor cortical excitability may be an important determinant of speed of processing following high intensity stimulation.

  6. AN EMPIRICAL STUDY ON SER VICE QUALITY PERCEPTIONS AND CONTINUANCE INTENTIO N IN MOBILE BANKING CONTEXT IN INDIA

    Directory of Open Access Journals (Sweden)

    Reji Kumar. G

    2012-04-01

    Full Text Available This paper examines the factors influencing the continuance decisions of the early adopters of m-banking services in Kerala, India. The study was designed in the backdrop of the issues faced by the banks to attract more customers irrespective of the huge mobile penetration in the country. The study used constructs adopted from Technology Acceptance Model along with constructs of perceived service quality, perceived credibility and perceived risk to empirically establish the influence on satisfaction and continuance usage intentions. The study could find strong linkage between perceived service quality, satisfaction and continuance intentions. The study also confirmed that after adoption of the technology, the customer finds satisfaction in the quality parameters of the service. Perceptions about the risks involved in m-banking had adverse impact on service quality and satisfaction. Continuance intentions were found solely dependent on satisfaction in the m-banking context in Kerala.

  7. Continuous corticosterone delivery via the drinking water or pellet implantation: A comparative study in mice.

    Science.gov (United States)

    Gasparini, Sylvia J; Weber, Marie-Christin; Henneicke, Holger; Kim, Sarah; Zhou, Hong; Seibel, Markus J

    2016-12-01

    In order to investigate the effects of glucocorticoid excess in rodent models, reliable methods of continuous glucocorticoid delivery are essential. The current study compares two methods of corticosterone (CS) delivery in regards to their ability to induce typical adverse outcomes such as fat accrual, insulin resistance, sarcopenia and bone loss. Eight-week-old mice received CS for 4weeks either via the drinking water (25-100μgCS/mL) or through weekly surgical implantation of slow release pellets containing 1.5mg CS. Both methods induced abnormal fat mass accrual, inhibited lean mass accretion and bone expansion, suppressed serum osteocalcin levels and induced severe insulin resistance. There was a clear dose dependant relationship between the CS concentrations in the drinking water and the severity of the phenotype, with a concentration of 50μg CS/mL drinking water most closely matching the metabolic changes induced by weekly pellet implantations. In contrast to pellets, however, delivery of CS via the drinking water resulted in a consistent diurnal exposure pattern, closely mimicking the kinetics of clinical glucocorticoid therapy. In addition, the method is safe, inexpensive, easily adjustable, non-invasive and avoids operative stress to the animals. Our data demonstrate that delivery of CS via the drinking water has advantages over weekly implantations of slow-release pellets. A dose of 50μg CS/mL drinking water is appropriate for the investigation of chronic glucocorticoid excess in mice.

  8. Study of continuous-wave domain fluorescence diffuse optical tomography for quality control on agricultural produce

    Energy Technology Data Exchange (ETDEWEB)

    Nadhira, Vebi, E-mail: vebi@tf.itb.ac.id; Kurniadi, Deddy, E-mail: vebi@tf.itb.ac.id; Juliastuti, E., E-mail: vebi@tf.itb.ac.id; Sutiswan, Adeline, E-mail: vebi@tf.itb.ac.id [Instrumentation and Control Research Group, Faculty of Industrial Technology, Institute Technology of Bandung, Ganesha 10 40132 Bandung (Indonesia)

    2014-03-24

    The importance of monitoring the quality of vegetables and fruits is prosperity by giving a competitive advantage for producer and providing a more healthy food for consumer. Diffuse Optical Tomography (DOT) is offering the possibility to detect the internal defects of the agricultural produce quality. Fluorescence diffuse optical tomography (FDOT) is the development of DOT, offering the possibilities to improve spatial resolution and to contrast image. The purpose of this research is to compare FDOT and DOT in forward analysis with continuous wave approach. The scattering and absorbing parameters of potatoes are used to represent the real condition. The object was illuminated by the NIR source from some positions on the boundary of object. A set of NIR detector are placed on the peripheral position of the object to measure the intensity of propagated or emitted light. In the simulation, we varied a condition of object then we analyzed the sensitivity of forward problem. The result of this study shows that FDOT has a better sensitivity than DOT and a better potential to monitor internal defects of agricultural produce because of the contrast value between optical and fluorescence properties of agricultural produce normal tissue and defects.

  9. Study of continuous-wave domain fluorescence diffuse optical tomography for quality control on agricultural produce

    Science.gov (United States)

    Nadhira, Vebi; Kurniadi, Deddy; Juliastuti, E.; Sutiswan, Adeline

    2014-03-01

    The importance of monitoring the quality of vegetables and fruits is prosperity by giving a competitive advantage for producer and providing a more healthy food for consumer. Diffuse Optical Tomography (DOT) is offering the possibility to detect the internal defects of the agricultural produce quality. Fluorescence diffuse optical tomography (FDOT) is the development of DOT, offering the possibilities to improve spatial resolution and to contrast image. The purpose of this research is to compare FDOT and DOT in forward analysis with continuous wave approach. The scattering and absorbing parameters of potatoes are used to represent the real condition. The object was illuminated by the NIR source from some positions on the boundary of object. A set of NIR detector are placed on the peripheral position of the object to measure the intensity of propagated or emitted light. In the simulation, we varied a condition of object then we analyzed the sensitivity of forward problem. The result of this study shows that FDOT has a better sensitivity than DOT and a better potential to monitor internal defects of agricultural produce because of the contrast value between optical and fluorescence properties of agricultural produce normal tissue and defects.

  10. Continuous Microfluidic Fabrication of Synthetic Asymmetric Vesicles for Membrane Biology Studies

    Science.gov (United States)

    Lu, Li; Schertzer, Jeffrey; Chiarot, Paul

    2015-11-01

    Membrane vesicles are spherical structures comprised of a single lipid bilayer enclosing an aqueous lumen. In nature, vesicles carry out many important functions in both eukaryotic and prokaryotic organisms. When preparing vesicles artificially, it is difficult to simultaneously control vesicle membrane asymmetry, size, unilamellarity, throughput, and monodispersity. Membrane asymmetry, where each leaflet of the lipid bilayer consists of a different lipid distribution, is of particular importance as it is a feature of nearly all natural membranes. In this study, we report on a novel microfluidic strategy to build monodisperse asymmetric vesicles with customized membrane composition, size, and luminal content at high-throughput. The microfluidic device consists of a triangular post region and two flow-focusing regions. The major steps of the vesicle fabrication process include: (1) assembly of the inner-leaflet, (2) continuous flow separation - replacing the inner-leaflet-lipid with the outer-leaflet-lipid, (3) assembly of the outer-leaflet, and (4) extraction of the intermediate oil layer. Membrane asymmetry and unilamellarity are confirmed using a fluorescence quenching assay and a membrane protein insertion assay, respectively. Our vesicle fabrication method can yield membrane asymmetries as high as 95%, which is maintained at a high-degree for over 30 hours. In addition, over 80% of the vesicles remain stable for at least 6 weeks. The effect of bilayer composition on the mechanical properties of the membrane and the role of small molecules on membrane architecture will be investigated.

  11. A Mathematical Modeling Study of Tracer Mixing in a Continuous Casting Tundish

    Science.gov (United States)

    Chen, Chao; Jonsson, Lage Tord Ingemar; Tilliander, Anders; Cheng, Guoguang; Jönsson, Pär Göran

    2015-02-01

    A mathematical model based on a water model was developed to study the tracer mixing in a single strand tundish. The mixing behavior of black ink and KCl solution was simulated by a mixed composition fluid model, and the data were validated by water modeling results. In addition, a model that solves the scalar transport equation (STE) without any physical properties of the tracer was studied and the results were compared to predictions using the density-coupled model. Furthermore, the mixing behaviors of different amounts of KCl tracers were investigated. Before the model was established, KCl tracer properties such as the KCl molecule diffusion (KMD), the water molecule self-diffusion (WSD) in KCl solution, and the KCl solution viscosity (KV) were evaluated. The RTD curve of 250 mL KCl for the KMD case was closer to the water modeling results than that of the case implemented with only density. Moreover, the ensemble average deviation of the RTD curves of the cases implemented with KMD + WSD, KMD + KV, and KMD + WSD + KV to the KMD case is less than 0.7 pct. Thus, the water self-diffusion and KV were neglected, while the KCl density and KMD were implemented in the current study. The flow pattern of black ink was similar to the STE result i.e., the fluid flowed upwards toward the top surface and formed a large circulating flow at the outlet nozzle. The flow behavior of the 100, 150, and 250 mL KCl cases exhibited a strong tendency to sink to the tundish bottom, and subsequently flow through the holes in the dam. Thereafter, it propagated toward the outlet nozzle. Regarding the KCl tracer amount, the tracer concentration propagated to the outlet nozzle much faster for the larger amount case than for the smaller amount cases. However, the flow pattern for the 50 mL KCl case was somewhat different. The fluid propagated to the top surface which acted like black ink during the initial injection, and subsequently the fluid flowed throughout the holes at a much slower pace

  12. How does hospitalization affect continuity of drug therapy: an exploratory study

    Directory of Open Access Journals (Sweden)

    Blozik E

    2016-08-01

    Full Text Available Eva Blozik,1–3 Andri Signorell,1 Oliver Reich1 1Department of Health Sciences, Helsana Group, Zürich, Switzerland; 2Department of Primary Medical Care, University Medical Centre Hamburg-Eppendorf, Hamburg, 3Department of Medicine, University Medical Centre Freiburg, Freiburg im Breisgau, Germany Introduction: Transitions between different levels of health care, such as hospital admission and discharge, pose a significant threat to the quality and continuity of medication therapy. This study aims to explore the role of hospitalization on medication changes as patients are transferred from and back to ambulatory care.Methods: Secondary analysis of claims data from Swiss residents with basic health insurance at the Helsana Group was performed. We evaluated medication invoices of patients who were hospitalized in a Swiss private hospital group in the year 2013. Medication changes were defined as discontinuation, new prescription, or change in the Anatomical Therapeutic Chemical (ATC Classification System level 4, which is equivalent to a change in the chemical/therapeutic/pharmacological subgroup. Multiple Poisson regression analysis was applied to evaluate whether medication change was predicted by socioeconomic or clinical patient characteristics or by a system factor (physician dispensing of medication allowed in canton of residence.Results: We investigated a total of 10,123 hospitalized patients, among whom a mean number of 3.85 (median 3.00 changes were identified. Change most frequently affected antihypertensives, analgesics, and antirheumatics. If patients were enrolled in a managed care plan, they were less likely to undergo changes. If a patient resided in a canton, in which physicians were allowed to dispense medication directly, the patient was more likely to experience change.Conclusion: There is considerable change in medication when patients shift between ambulatory and inpatient health care levels. This interruption of medication

  13. Patient-centred communication intervention study to evaluate nurse-patient interactions in complex continuing care

    Directory of Open Access Journals (Sweden)

    McGilton Katherine S

    2012-10-01

    Full Text Available Abstract Background Communication impairment is a frequent consequence of stroke. Patients who cannot articulate their needs respond with frustration and agitation, resulting in poor optimization of post-stroke functions. A key component of patient-centred care is the ability of staff to communicate in a way that allows them to understand the patient’s needs. We developed a patient-centred communication intervention targeting registered and unregulated nursing staff caring for complex continuing care patients with communication impairments post stroke. Research objectives include 1 examining the effects of the intervention on patients’ quality of life, depression, satisfaction with care, and agitation; and (2 examining the extent to which the intervention improves staff’s attitudes and knowledge in caring for patients with communication impairments. The intervention builds on a previous pilot study. Methods/design A quasi-experimental repeated measures non-equivalent control group design in a complex continuing care facility is being used. Patients with a communication impairment post-stroke admitted to the facility are eligible to participate. All staff nurses are eligible. Baseline data are collected from staff and patients. Follow-up will occur at 1 and 3 months post-intervention. Subject recruitment and data collection from 60 patients and 30 staff will take approximately 36 months. The Patient-Centred Communication Intervention consists of three components: (1 development of an individualized patient communication care plan; (2 a one-day workshop focused on communication and behavioural management strategies for nursing staff; and (3 a staff support system. The intervention takes comprehensive patient assessments into account to inform the development of communication and behavioural strategies specifically tailored to each patient. Discussion The Patient-Centred Communication Intervention will provide staff with strategies to

  14. US EPA Base Study Standard Operating Procedure for Continuous Monitoring of Outdoor Air

    Science.gov (United States)

    The procedure described is intended for monitoring continuously and simultaneously outdoor air quality parameters that are most commonly associated with indoor air quality: the concentrations of carbon dioxide (CO2) and carbon monoxide (CO), temperature, nd relative humidity (RH).

  15. A comparative study of continuous versus interrupted suturing for repair of episiotomy or second degree perineal tear

    OpenAIRE

    Lopamudra Jena; Shyama Kanungo

    2015-01-01

    Background: This study has been taken up to assess the effects of continuous versus interrupted suturing methods on the incidence of short and long term postpartum maternal morbidity experienced by women following repair of episiotomy or second-degree perineal tears after vaginal birth. Methods: This comparative prospective study was conducted in department of obstetrics and gynaecology of S.C.B. medical college, Cuttack, Odisha to compare continuous suturing technique with interrupted m...

  16. Nanobiotechnology advanced antifouling surfaces for the continuous electrochemical monitoring of glucose in whole blood using a lab-on-a-chip.

    Science.gov (United States)

    Picher, Maria M; Küpcü, Seta; Huang, Chun-Jen; Dostalek, Jakub; Pum, Dietmar; Sleytr, Uwe B; Ertl, Peter

    2013-05-07

    In the current work we have developed a lab-on-a-chip containing embedded amperometric sensors in four microreactors that can be addressed individually and that are coated with crystalline surface protein monolayers to provide a continuous, stable, reliable and accurate detection of blood glucose. It is envisioned that the microfluidic device will be used in a feedback loop mechanism to assess natural variations in blood glucose levels during hemodialysis to allow the individual adjustment of glucose. Reliable and accurate detection of blood glucose is accomplished by simultaneously performing (a) blood glucose measurements, (b) autocalibration routines, (c) mediator-interferences detection, and (d) background subtractions. The electrochemical detection of blood glucose variations in the absence of electrode fouling events is performed by integrating crystalline surface layer proteins (S-layer) that function as an efficient antifouling coating, a highly-oriented immobilization matrix for biomolecules and an effective molecular sieve with pore sizes of 4 to 5 nm. We demonstrate that the S-layer protein SbpA (from Lysinibacillus sphaericus CCM 2177) readily forms monomolecular lattice structures at the various microchip surfaces (e.g. glass, PDMS, platinum and gold) within 60 min, eliminating unspecific adsorption events in the presence of human serum albumin, human plasma and freshly-drawn blood samples. The highly isoporous SbpA-coating allows undisturbed diffusion of the mediator between the electrode surface, thus enabling bioelectrochemical measurements of glucose concentrations between 500 μM to 50 mM (calibration slope δI/δc of 8.7 nA mM(-1)). Final proof-of-concept implementing the four microfluidic microreactor design is demonstrated using freshly drawn blood. Accurate and drift-free assessment of blood glucose concentrations (6. 4 mM) is accomplished over 130 min at 37 °C using immobilized enzyme glucose oxidase by calculating the difference between

  17. Radar studies of the planets. [radar measurements of lunar surface, Mars, Mercury, and Venus

    Science.gov (United States)

    Ingalls, R. P.; Pettengill, G. H.; Rogers, A. E. E.; Sebring, P. B. (Editor); Shapiro, I. I.

    1974-01-01

    The radar measurements phase of the lunar studies involving reflectivity and topographic mapping of the visible lunar surface was ended in December 1972, but studies of the data and production of maps have continued. This work was supported by Manned Spacecraft Center, Houston. Topographic mapping of the equatorial regions of Mars has been carried out during the period of each opposition since that of 1967. The method comprised extended precise traveling time measurements to a small area centered on the subradar point. As measurements continued, planetary motions caused this point to sweep out extensive areas in both latitude and longitude permitting the development of a fairly extensive topographical map in the equatorial region. Radar observations of Mercury and Venus have also been made over the past few years. Refinements of planetary motions, reflectivity maps and determinations of rotation rates have resulted.

  18. Computational and Experimental Study of the Transient Transport Phenomena in a Full-Scale Twin-Roll Continuous Casting Machine

    Science.gov (United States)

    Xu, Mianguang; Li, Zhongyang; Wang, Zhaohui; Zhu, Miaoyong

    2017-02-01

    To gain a fundamental understanding of the transient fluid flow in twin-roll continuous casting, the current paper applies both large eddy simulation (LES) and full-scale water modeling experiments to investigate the characteristics of the top free surface, stirring effect of the roll rotation, boundary layer fluctuations, and backflow stability. The results show that, the characteristics of the top free surface and the flow field in the wedge-shaped pool region are quite different with/without the consideration of the roll rotation. The roll rotation decreases the instantaneous fluctuation range of the top free surface, but increases its horizontal velocity. The stirring effect of the roll rotating makes the flow field more homogenous and there exists clear shear flow on the rotating roll surface. The vortex shedding induced by the Kármán Vortex Street from the submerged entry nozzle (SEN) causes the "velocity magnitude wave" and strongly influences the boundary layer stability and the backflow stability. The boundary layer fluctuations or the "velocity magnitude wave" induced by the vortex shedding could give rise to the internal porosity. In strip continuous casting process, the vortex shedding phenomenon indicates that the laminar flow can give rise to instability and that it should be made important in the design of the feeding system and the setting of the operating parameters.

  19. Discrete Surface Modeling Based on Google Earth: A Case Study

    CERN Document Server

    Mei, Gang; Xu, Nengxiong

    2012-01-01

    Google Earth (GE) has become a powerful tool for geological, geophysical and geographical modeling; yet GE can be accepted to acquire elevation data of terrain. In this paper, we present a real study case of building the discrete surface model (DSM) at Haut-Barr Castle in France based on the elevation data of terrain points extracted from GE using the COM API. We first locate the position of Haut-Barr Castle and determine the region of the study area, then extract elevation data of terrain at Haut-Barr, and thirdly create a planar triangular mesh that covers the study area and finally generate the desired DSM by calculating the elevation of vertices in the planar mesh via interpolating with Universal Kriging (UK) and Inverse Distance Weighting (IDW). The generated DSM can reflect the features of the ground surface at Haut-Barr well, and can be used for constructingthe Sealed Engineering Geological Model (SEGM) in further step.

  20. [Continuous insulin therapy versus multiple insulin injections in the management of type 1 diabetes: a longitutinal study].

    Science.gov (United States)

    Ribeiro, Maria Estela Bellini; Del Roio Liberatore Junior, Raphael; Custodio, Rodrigo; Martinelli Junior, Carlos Eduardo

    2016-01-01

    To compare multiple doses of insulin and continuous insulin infusion therapy as treatment for type 1 diabetes melito. 40 patients with type 1 diabetes melito (21 female) with ages between 10 and 20 years (mean=14.2) and mean duration of diabetes of 7 years used multiple doses of insulin for at least 6 months and after that, continuous insulin infusion therapy for at least 6 months. Each one of the patients has used multiple doses of insulin and continuous insulin infusion therapy. For analysis of HbA1c, mean glycated hemoglobin levels (mHbA1c) were obtained during each treatment period (multiple doses of insulin and continuous insulin infusion therapy period). Although mHbA1c levels were lower during continuous insulin infusion therapy the difference was not statistically significant. During multiple doses of insulin, 14.2% had mHbA1c values below 7.5% vs. 35.71% while on continuous insulin infusion therapy; demonstrating better glycemic control with the use of continuous insulin infusion therapy. During multiple doses of insulin, 15-40 patients have severe hypoglycemic events versus 5-40 continuous insulin infusion therapy. No episodes of ketoacidosis events were recorded. This is the first study with this design comparing multiple doses of insulin and continuous insulin infusion therapy in Brazil showing no significant difference in HbA1c; hypoglycemic events were less frequent during continuous insulin infusion therapy than during multiple doses of insulin and the percentage of patients who achieved a HbA1c less than 7.5% was greater during continuous insulin infusion therapy than multiple doses of insulin therapy. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.