WorldWideScience

Sample records for surface method incorporating

  1. A simple statistical method for analyzing flood susceptibility with incorporating rainfall and impervious surface

    Science.gov (United States)

    Chiang, Shou-Hao; Chen, Chi-Farn

    2016-04-01

    Flood, as known as the most frequent natural hazard in Taiwan, has induced severe damages of residents and properties in urban areas. The flood risk is even more severe in Tainan since 1990s, with the significant urban development over recent decades. Previous studies have indicated that the characteristics and the vulnerability of flood are affected by the increase of impervious surface area (ISA) and the changing climate condition. Tainan City, in southern Taiwan is selected as the study area. This study uses logistic regression to functionalize the relationship between rainfall variables, ISA and historical flood events. Specifically, rainfall records from 2001 to 2014 were collected and mapped, and Landsat images of year 2001, 2004, 2007, 2010 and 2014 were used to generate the ISA with SVM (support vector machine) classifier. The result shows that rainfall variables and ISA are significantly correlated to the flood occurrence in Tainan City. With applying the logistic function, the likelihood of flood occurrence can be estimated and mapped over the study area. This study suggests the method is simple and feasible for rapid flood susceptibility mapping, when real-time rainfall observations can be available, and it has potential for future flood assessment, with incorporating climate change projections and urban growth prediction.

  2. Ion-beam method characterization of erbium incorporation into glass surface for photonics applications

    Czech Academy of Sciences Publication Activity Database

    Macková, Anna; Peřina, Vratislav; Havránek, Vladimír; Třešnáková-Nebolová, P.; Špirková, J.; Telezhniková, O.

    2004-01-01

    Roč. 566, č. 1 (2004), s. 111-114 ISSN 0039-6028 R&D Projects: GA ČR GP102/01/D069 Institutional research plan: CEZ:AV0Z1048901 Keywords : lanthanides * glass surfaces * X-ray emission Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.168, year: 2004

  3. Surface characterization and biological evaluation of silver-incorporated DLC coatings fabricated by hybrid RF PACVD/MS method.

    Science.gov (United States)

    Bociąga, Dorota; Jakubowski, Witold; Komorowski, Piotr; Sobczyk-Guzenda, Anna; Jędrzejczak, Anna; Batory, Damian; Olejnik, Anna

    2016-06-01

    Since the biological response of the body towards an implanted material is mainly governed by its surface properties, biomaterials are improved by various kinds of coatings. Their role is to provide good mechanical and biological characteristics, and exclude some disadvantages like post-implantation infections. This phenomenon may be reduced by introduction of silver as an antibacterial agent. This study evaluates the Ag-DLC films synthesized by the hybrid RF PACVD/MS method according to the patent number PL401955-A1 worked out inter alia by the authors. Such tests as XPS, SEM, EDS, AFM, FTIR, Raman and ICP-TOF-MS were used to determine surface properties of the coatings. The obtained results were correlated with the biological response estimated on the basis of cells viability assay (osteoblast cells line Saos-2) and bacterial colonization test (Escherichia coli strain DH5α). Results showed that the hybrid RF PACVD/MS method allows one to get tight coating preventing the diffusion of harmful elements from the metallic substrate. Ag concentration increases with the growing power density, it occurs in metallic state, does not create chemical bonds and is evenly dispersed within the DLC matrix in the form of nanoscale silver clusters. Increasing silver content above 2at.% improves bactericidal properties, but decreases cell viability. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Nonlinear free vibration of piezoelectric nanobeams incorporating surface effects

    International Nuclear Information System (INIS)

    Hosseini-Hashemi, Shahrokh; Nahas, Iman; Fakher, Mahmood; Nazemnezhad, Reza

    2014-01-01

    In this study, the nonlinear free vibration of piezoelectric nanobeams incorporating surface effects (surface elasticity, surface tension, and surface density) is studied. The governing equation of the piezoelectric nanobeam is derived within the framework of Euler–Bernoulli beam theory with the von Kármán geometric nonlinearity. In order to satisfy the balance conditions between the nanobeam bulk and its surfaces, the component of the bulk stress, σ zz , is assumed to vary linearly through the nanobeam thickness. An exact solution is obtained for the natural frequencies of a simply supported piezoelectric nanobeam in terms of the Jacobi elliptic functions using the free vibration mode shape of the corresponding linear problem. Then, the influences of the surface effects and the piezoelectric field on the nonlinear free vibration of nanobeams made of aluminum and silicon with positive and negative surface elasticity, respectively, have been studied for various properties of the piezoelectric field, various nanobeam sizes and amplitude ratios. It is observed that if the Young’s modulus of a nanobeam is lower, the effect of the piezoelectric field on the frequency ratios (FRs) of the nanobeam will be greater. In addition, it is seen that by increasing the nanobeam length so that the nanobeam cross section is set to be constant, the surface effects and the piezoelectric field with negative voltage values increases the FRs, whereas it is the other way around when the nanobeam cross section is assumed to be dependent on the length of the nanobeam. (paper)

  5. Incorporation of metal nanoparticles into wood substrate and methods

    Science.gov (United States)

    Rector, Kirk D; Lucas, Marcel

    2015-11-04

    Metal nanoparticles were incorporated into wood. Ionic liquids were used to expand the wood cell wall structure for nanoparticle incorporation into the cell wall structure. Nanoparticles of elemental gold or silver were found to be effective surface enhanced Raman spectroscopy (SERS) imaging contrast or sensing agents. Nanoparticles of elemental iron were found to be efficient microwave absorbers and caused localized heating for disrupting the integrity of the lignocellulosic matrix. Controls suggest that the localized heating around the iron nanoparticles reduces losses of cellulose in the form of water, volatiles and CO.sub.2. The ionic liquid is needed during the incorporation process at room temperature. The use of small amounts of ionic liquid combined with the absence of an ionic liquid purification step and a lower energy and water use are expected to reduce costs in an up-scaled pretreatment process.

  6. Gold Incorporated Mesoporous Silica Thin Film Model Surface as a Robust SERS and Catalytically Active Substrate

    Directory of Open Access Journals (Sweden)

    Anandakumari Chandrasekharan Sunil Sekhar

    2016-05-01

    Full Text Available Ultra-small gold nanoparticles incorporated in mesoporous silica thin films with accessible pore channels perpendicular to the substrate are prepared by a modified sol-gel method. The simple and easy spin coating technique is applied here to make homogeneous thin films. The surface characterization using FESEM shows crack-free films with a perpendicular pore arrangement. The applicability of these thin films as catalysts as well as a robust SERS active substrate for model catalysis study is tested. Compared to bare silica film our gold incorporated silica, GSM-23F gave an enhancement factor of 103 for RhB with a laser source 633 nm. The reduction reaction of p-nitrophenol with sodium borohydride from our thin films shows a decrease in peak intensity corresponding to –NO2 group as time proceeds, confirming the catalytic activity. Such model surfaces can potentially bridge the material gap between a real catalytic system and surface science studies.

  7. Method Development for Efficient Incorporation of Unnatural Amino Acids

    KAUST Repository

    Harris, Paul D.

    2014-04-01

    The synthesis of proteins bearing unnatural amino acids has the potential to enhance and elucidate many processes in biochemistry and molecular biology. There are two primary methods for site specific unnatural amino acid incorporation, both of which use the cell’s native protein translating machinery: in vitro chemical acylation of suppressor tRNAs and the use of orthogonal amino acyl tRNA synthetases. Total chemical synthesis is theoretically possible, but current methods severely limit the maximum size of the product protein. In vivo orthogonal synthetase methods suffer from the high cost of the unnatural amino acid. In this thesis I sought to address this limitation by increasing cell density, first in shake flasks and then in a bioreactor in order to increase the yield of protein per amount of unnatural amino acid used. In a parallel project, I used the in vitro chemical acylation system to incorporate several unnatural amino acids, key among them the fluorophore BODIPYFL, with the aim of producing site specifically fluorescently labeled protein for single molecule FRET studies. I demonstrated successful incorporation of these amino acids into the trial protein GFP, although incorporation was not demonstrated in the final target, FEN1. This also served to confirm the effectiveness of a new procedure developed for chemical acylation.

  8. Incorporating Skew into RMS Surface Roughness Probability Distribution

    Science.gov (United States)

    Stahl, Mark T.; Stahl, H. Philip.

    2013-01-01

    The standard treatment of RMS surface roughness data is the application of a Gaussian probability distribution. This handling of surface roughness ignores the skew present in the surface and overestimates the most probable RMS of the surface, the mode. Using experimental data we confirm the Gaussian distribution overestimates the mode and application of an asymmetric distribution provides a better fit. Implementing the proposed asymmetric distribution into the optical manufacturing process would reduce the polishing time required to meet surface roughness specifications.

  9. The Impact of Incorporating Antimicrobials into Implant Surfaces.

    Science.gov (United States)

    Hickok, N J; Shapiro, I M; Chen, A F

    2018-01-01

    With the increase in numbers of joint replacements, spinal surgeries, and dental implantations, there is an urgent need to combat implant-associated infection. In addition to stringent sterile techniques, an efficacious way to prevent this destructive complication is to create new implants with antimicrobial properties. Specifically, these implants must be active in the dental implant environment where the implant is bathed in the glycoprotein-rich salivary fluids that enhance bacterial adhesion, and propagation, and biofilm formation. However, in designing an antimicrobial surface, a balance must be struck between antimicrobial activity and the need for the implant to interact with the bone environment. Three types of surfaces have been designed to combat biofilm formation, while attempting to maintain osseous interactions: 1) structured surfaces where topography, usually at the nanoscale, decreases bacterial adhesion sufficiently to retard establishment of infection; 2) surfaces that actively elute antimicrobials to avert bacterial adhesion and promote killing; and 3) surfaces containing permanently bonded agents that generate antimicrobial surfaces that prevent long-term bacterial adhesion. Both topographical and elution surfaces exhibit varying, albeit limited, antimicrobial activity in vitro. With respect to covalent coupling, we present studies on the ability of the permanent antimicrobial surfaces to kill organisms while fostering osseointegration. All approaches have significant drawbacks with respect to stability and efficacy, but the permanent surfaces may have an edge in creating a long-term antibacterial environment.

  10. Incorporating contact angles in the surface tension force with the ACES interface curvature scheme

    Science.gov (United States)

    Owkes, Mark

    2017-11-01

    In simulations of gas-liquid flows interacting with solid boundaries, the contact line dynamics effect the interface motion and flow field through the surface tension force. The surface tension force is directly proportional to the interface curvature and the problem of accurately imposing a contact angle must be incorporated into the interface curvature calculation. Many commonly used algorithms to compute interface curvatures (e.g., height function method) require extrapolating the interface, with defined contact angle, into the solid to allow for the calculation of a curvature near a wall. Extrapolating can be an ill-posed problem, especially in three-dimensions or when multiple contact lines are near each other. We have developed an accurate methodology to compute interface curvatures that allows for contact angles to be easily incorporated while avoiding extrapolation and the associated challenges. The method, known as Adjustable Curvature Evaluation Scale (ACES), leverages a least squares fit of a polynomial to points computed on the volume-of-fluid (VOF) representation of the gas-liquid interface. The method is tested by simulating canonical test cases and then applied to simulate the injection and motion of water droplets in a channel (relevant to PEM fuel cells).

  11. A method to incorporate uncertainty in the classification of remote sensing images

    OpenAIRE

    Gonçalves, Luísa M. S.; Fonte, Cidália C.; Júlio, Eduardo N. B. S.; Caetano, Mario

    2009-01-01

    The aim of this paper is to investigate if the incorporation of the uncertainty associated with the classification of surface elements into the classification of landscape units (LUs) increases the results accuracy. To this end, a hybrid classification method is developed, including uncertainty information in the classification of very high spatial resolution multi-spectral satellite images, to obtain a map of LUs. The developed classification methodology includes the following...

  12. Incorporating classic adsorption isotherms into modern surface complexation models: implications for sorption of radionuclides

    International Nuclear Information System (INIS)

    Kulik, D.A.

    2005-01-01

    Full text of publication follows: Computer-aided surface complexation models (SCM) tend to replace the classic adsorption isotherm (AI) analysis in describing mineral-water interface reactions such as radionuclide sorption onto (hydr) oxides and clays. Any site-binding SCM based on the mole balance of surface sites, in fact, reproduces the (competitive) Langmuir isotherm, optionally amended with electrostatic Coulomb's non-ideal term. In most SCM implementations, it is difficult to incorporate real-surface phenomena (site heterogeneity, lateral interactions, surface condensation) described in classic AI approaches other than Langmuir's. Thermodynamic relations between SCMs and AIs that remained obscure in the past have been recently clarified using new definitions of standard and reference states of surface species [1,2]. On this basis, a method for separating the Langmuir AI into ideal (linear) and non-ideal parts [2] was applied to multi-dentate Langmuir, Frumkin, and BET isotherms. The aim of this work was to obtain the surface activity coefficient terms that make the SCM site mole balance constraints obsolete and, in this way, extend thermodynamic SCMs to cover sorption phenomena described by the respective AIs. The multi-dentate Langmuir term accounts for the site saturation with n-dentate surface species, as illustrated on modeling bi-dentate U VI complexes on goethite or SiO 2 surfaces. The Frumkin term corrects for the lateral interactions of the mono-dentate surface species; in particular, it has the same form as the Coulombic term of the constant-capacitance EDL combined with the Langmuir term. The BET term (three parameters) accounts for more than a monolayer adsorption up to the surface condensation; it can potentially describe the surface precipitation of nickel and other cations on hydroxides and clay minerals. All three non-ideal terms (in GEM SCMs implementation [1,2]) by now are used for non-competing surface species only. Upon 'surface dilution

  13. Incorporating breeding abundance into spatial assignments on continuous surfaces.

    Science.gov (United States)

    Rushing, Clark S; Marra, Peter P; Studds, Colin E

    2017-06-01

    Determining the geographic connections between breeding and nonbreeding populations, termed migratory connectivity, is critical to advancing our understanding of the ecology and conservation of migratory species. Assignment models based on stable isotopes historically have been an important tool for studying migratory connectivity of small-bodied species, but the low resolution of these assignments has generated interest into combining isotopes with other sources in information. Abundance is one of the most appealing data sources to include in isotope-based assignments, but there are currently no statistical methods or guidelines for optimizing the contribution of stable isotopes and abundance for inferring migratory connectivity. Using known-origin stable-hydrogen isotope samples of six Neotropical migratory bird species, we rigorously assessed the performance of assignment models that differentially weight the contribution of the isotope and abundance data. For two species with adequate sample sizes, we used Pareto optimality to determine the set of models that simultaneously minimized both assignment error rate and assignment area. We then assessed the ability of the top models from these two species to improve assignments of the remaining four species compared to assignments based on isotopes alone. We show that the increased precision of models that include abundance is often offset by a large increase in assignment error. However, models that optimally weigh the abundance data relative to the isotope data can result in higher precision and, in some cases, lower error than models based on isotopes alone. The top models, however, depended on the distribution of relative breeding abundance, with patchier distributions requiring stronger downweighting of abundance, and we present general guidelines for future studies. These results confirm that breeding abundance can be an important source of information for studies investigating broad-scale movements of

  14. Lactoperoxidase catalyzed radioiodination of cell surface immunoglobulin: incorporated radioactivity may not reflect relative cell surface Ig density

    International Nuclear Information System (INIS)

    Wilder, R.L.; Yuen, C.C.; Mage, R.G.

    1979-01-01

    Rabbit and mouse splenic lymphocytes were radioiodinated by the lactoperoxidase technique, extracted with non-ionic detergent, immunoprecipitated with high titered rabbit anti-kappa antisera, and compared by SDS-PAGE. Mouse sIg peaks were reproducibly larger in size than rabbit sIg peaks (often greater than 10 times). Neither differences in incorporation of label into the rabbit cell surface, nor differences in average sIg density explain this result. Total TCA-precipitable radioactivity was similar in each species. Estimation of the relative amounts of sIg in the mouse and rabbit showed similar average sIg densities. Differences in detergent solubility, proteolytic lability, or antisera used also do not adequately account for this difference. Thus, these data indicate that radioactivity incorporated after lactoperoxidase catalyzed cell surface radioiodination may not reflect cell surface Ig density. Conclusions about cell surface density based upon relative incorporation of radioactivity should be confirmed by other approaches

  15. Ultra-high vacuum surface analysis study of rhodopsin incorporation into supported lipid bilayers.

    Science.gov (United States)

    Michel, Roger; Subramaniam, Varuni; McArthur, Sally L; Bondurant, Bruce; D'Ambruoso, Gemma D; Hall, Henry K; Brown, Michael F; Ross, Eric E; Saavedra, S Scott; Castner, David G

    2008-05-06

    Planar supported lipid bilayers that are stable under ambient atmospheric and ultra-high-vacuum conditions were prepared by cross-linking polymerization of bis-sorbylphosphatidylcholine (bis-SorbPC). X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to investigate bilayers that were cross-linked using either redox-initiated radical polymerization or ultraviolet photopolymerization. The redox method yields a more structurally intact bilayer; however, the UV method is more compatible with incorporation of transmembrane proteins. UV polymerization was therefore used to prepare cross-linked bilayers with incorporated bovine rhodopsin, a light-activated, G-protein-coupled receptor (GPCR). A previous study (Subramaniam, V.; Alves, I. D.; Salgado, G. F. J.; Lau, P. W.; Wysocki, R. J.; Salamon, Z.; Tollin, G.; Hruby, V. J.; Brown, M. F.; Saavedra, S. S. J. Am. Chem. Soc. 2005, 127, 5320-5321) showed that rhodopsin retains photoactivity after incorporation into UV-polymerized bis-SorbPC, but did not address how the protein is associated with the bilayer. In this study, we show that rhodopsin is retained in supported bilayers of poly(bis-SorbPC) under ultra-high-vacuum conditions, on the basis of the increase in the XPS nitrogen concentration and the presence of characteristic amino acid peaks in the ToF-SIMS data. Angle-resolved XPS data show that the protein is inserted into the bilayer, rather than adsorbed on the bilayer surface. This is the first study to demonstrate the use of ultra-high-vacuum techniques for structural studies of supported proteolipid bilayers.

  16. Hepatitis B surface antigen incorporated in dissolvable microneedle array patch is antigenic and thermostable.

    Science.gov (United States)

    Poirier, Danielle; Renaud, Frédéric; Dewar, Vincent; Strodiot, Laurent; Wauters, Florence; Janimak, Jim; Shimada, Toshio; Nomura, Tatsuya; Kabata, Koki; Kuruma, Koji; Kusano, Takayuki; Sakai, Masaki; Nagasaki, Hideo; Oyamada, Takayoshi

    2017-11-01

    Alternatives to syringe-based administration are considered for vaccines. Intradermal vaccination with dissolvable microneedle arrays (MNA) appears promising in this respect, as an easy-to-use and painless method. In this work, we have developed an MNA patch (MNAP) made of hydroxyethyl starch (HES) and chondroitin sulphate (CS). In swines, hepatitis B surface antigen (HBsAg) formulated with the saponin QS-21 as adjuvant, both incorporated in HES-based MNAP, demonstrated the same level of immunogenicity as a commercially available aluminum-adjuvanted HBsAg vaccine, after two immunizations 28 days apart. MNAP application was associated with transient skin reactions (erythema, lump, scab), particularly evident when the antigen was delivered with the adjuvant. The thermostability of the adjuvanted antigen when incorporated in the HES-based matrix was also assessed by storing MNAP at 37, 45 or 50 °C for up to 6 months. We could demonstrate that antigenicity was retained at 37 and 45 °C and only a 10% loss was observed after 6 months at 50 °C. Our results are supportive of MNAP as an attractive alternative to classical syringe-based vaccination. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Surface decontamination compositions and methods

    Science.gov (United States)

    Wright,; Karen, E [Idaho Falls, ID; Cooper, David C [Idaho Falls, ID; Peterman, Dean R [Idaho Falls, ID; Demmer, Ricky L [Idaho Falls, ID; Tripp, Julia L [Pocatello, ID; Hull, Laurence C [Idaho Falls, ID

    2011-03-29

    Clay-based compositions capable of absorbing contaminants from surfaces or objects having surface faces may be applied to a surface and later removed, the removed clay-based compositions absorbing at least a portion of the contaminant from the surface or object to which it was applied.

  18. Ab initio-based approach to reconstruction, adsorption and incorporation on GaN surfaces

    International Nuclear Information System (INIS)

    Ito, T; Akiyama, T; Nakamura, K

    2012-01-01

    Reconstruction, adsorption and incorporation on various GaN surfaces are systematically investigated using an ab initio-based approach that predicts the surface phase diagram as functions of temperature and beam-equivalent pressure (BEP). The calculated results for GaN surface reconstructions with polar (0 0 0 1), nonpolar (1 1 −2 0), semipolar (1 −1 0 1) and semipolar (1 1 −2 2) orientations imply that reconstructions on GaN surfaces with Ga adlayers generally appear on the polar and the semipolar surfaces, while the stable ideal surface without Ga adsorption is found on the nonpolar GaN(1 1 −2 0) surface because it satisfies the electron counting rule. The hydrogen adsorption on GaN(0 0 0 1) and GaN(1 1 −2 0) realizes several surface structures forming N–H and Ga–NH 2 bonds on their surfaces that depend on temperature and Ga BEP during metal-organic vapor-phase epitaxy (MOVPE). In contrast, the stable structures due to hydrogen adsorption on the semipolar GaN(1 −1 0 1) and GaN(1 1 −2 2) surfaces are not varied over the wide range of temperature and Ga BEP. This implies that the hydrogen adsorbed stable structures are expected to emerge on the semipolar surfaces during MOVPE regardless of the growth conditions. Furthermore, we clarify that Mg incorporation on GaN(1 −1 0 1) surfaces is enhanced by hydrogen adsorption consistent with experimental findings

  19. SU-E-T-489: Incorporating Skin Flash Into VMAT WBI: Impacts On Surface Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Buele, A Bejarano; Tanny, S; Warrell, G; Parsai, E [University of Toledo Medical Center, Toledo, OH (United States)

    2015-06-15

    Purpose: Increased use of inverse planning limits the amount of skin flash in whole breast irradiation (WBI). Strategies to incorporate flash into inverse-planned treatments involve overriding air to the density of water or tissue. This introduces uncertainties to the superficial dose distribution, potentially degrading the coverage at the skin-bolus interface. We investigate the accuracy of various commonly used bolus materials to incorporate flash in VMAT WBI plans while minimizing the perturbation near the skin. Methods: We obtained a CT-simulation of an anthropomorphic phantom with a breast attachment. Three VMAT plans were created with different boluses: 1 cm of 1 g/cm{sup 3} bolus (Superflab), 1 cm of 0.65 g/cm{sup 3} bolus (wet towels), and 1 cm of g/cm{sup 3} bolus with 2 dose levels accounting for the difference between bolus and tissue density. The PTV was extended into the bolus, outside the patient body contour to incorporate flash. OSLDs were used to obtain surface doses at the medial, lateral and tip sites of the breast. Each plan was irradiated four times using CBCT for positioning and dosimeter localization. Results: The average thickness of the wet-towel bolus on delivery was 8 mm with a CBCT-measured density of 0.6 g/cm{sup 3}. OSLD measurements demonstrated good agreement with predicted doses from Pinnacle. Average deviations were −5.7%, −2.5%, and −2.6% for plans 1, 2, and 3, respectively. OSLDs placed at the medial and lateral portions of the breast showed the largest average deviations. The maximum recorded deviation from planned values was −8.6%. The largest dose fluctuations occurred near areas where the bolus failed to properly conform to the breast contour. Conclusion: Use of wet-towel bolus improved dose delivery accuracy compared to standard Superflab bolus. Areas of poor bolus conformity adversely affected dose delivery. We recommend the use of wet-towel bolus over Superflab bolus for VMAT WBI.

  20. Surface treatment and protection method for cadmium zinc telluride crystals

    Science.gov (United States)

    Wright, Gomez W.; James, Ralph B.; Burger, Arnold; Chinn, Douglas A.

    2003-01-01

    A method for treatment of the surface of a CdZnTe (CZT) crystal that provides a native dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals. A two step process is disclosed, etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and after attachment of electrical contacts, passivating the CZT crystal surface with a solution of 10 w/o NH.sub.4 F and 10 w/o H.sub.2 O.sub.2 in water.

  1. Surface Treatment And Protection Method For Cadium Zinc Telluride Crystals

    Science.gov (United States)

    Wright, Gomez W.; James, Ralph B.; Burger, Arnold; Chinn, Douglas A.

    2006-02-21

    A method for treatment of the surface of a CdZnTe (CZT) crystal that provides a native dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals. A two step process is disclosed, etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and after attachment of electrical contacts, passivating the CZT crystal surface with a solution of 10 w/o NH4F and 10 w/o H2O2 in water.

  2. Effects of titanium surface anodization with CaP incorporation on human osteoblastic response

    Science.gov (United States)

    OLIVEIRA, Natássia Cristina Martins; MOURA, Camilla Christian Gomes; ZANETTA-BARBOSA, Darceny; MENDONÇA, Daniela Baccelli Silveira; MENDONÇA, Gustavo; DECHICHI, Paula

    2015-01-01

    In this study we investigated whether anodization with calcium phosphate (CaP) incorporation (Vulcano®) enhances growth factors secretion, osteoblast-specific gene expression, and cell viability, when compared to acid etched surfaces (Porous®) and machined surfaces (Screw®) after 3 and 7 days. Results showed significant cell viability for Porous and Vulcano at day 7, when compared with Screw (p=0.005). At the same time point, significant differences regarding runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and bone sialoprotein (BSP) expression were found for all surfaces (p0.05). Although no significant correlation was found for growth factors secretion and Runx2 expression, a significant positive correlation between this gene and ALP/BSP expression showed that their strong association is independent on the type of surface. The incorporation of CaP affected the biological parameters evaluated similar to surfaces just acid etched. The results presented here support the observations that roughness also may play an important role in determining cell response. PMID:23498218

  3. Incorporation of alternating plasticity in the shakedown method

    International Nuclear Information System (INIS)

    Buckthorpe, D.E.; White, P.S.

    1993-01-01

    Shakedown is the process whereby behaviour becomes wholly or predominantly elastic and in particular no further change in the dimensions of a structure occurs after a few cycles of loading. If the loading is increased progressively, a level is reached where shakedown does not occur and the dimensions of the structure continue to change. This is the condition known as ratcheting. Structural materials and weldments are of limited ductility and therefore ratcheting is not acceptable in plant where large numbers of load applications occur. All successful plant must therefore operate within the shakedown limit. The principles of shakedown have been accepted for many years but their use in design has been hindered by difficulty of performing analysis. The method uses the elastic analysis of a load cycle and requires the estimation of a constant (in time) residual stress field which is used to obtain a reference stress for creep damage estimates and local estimates of fatigue damage. The post-processor ADAPT is the basic special computational tool within the shakedown method for performing this estimation. The emphasis of this paper concerns an improvement to the ADAPT algorithms to give better estimates in cases of overall shakedown where a substantial elastic core is maintained but small regions upto 20% of a section may be beyond yield. The present methodology is based on lower bound shakedown theory and in the case of overall shakedown evaluates an approximate self equilibrating residual stress field which minimises the region of plasticity. The new treatment estimates a representative time independent field through a criterion based on approximate symmetrisation of the local stress cycle. A modification of the ADAPT algorithm within the shakedown design method has been described which is intended to provide a residual stress that gives a more nearly symmetrical stress-trajectory in cases of overall shakedown. The modified algorithm may imply a small penalty in

  4. Quantum-Mechanical Methods for Quantifying Incorporation of Contaminants in Proximal Minerals

    Directory of Open Access Journals (Sweden)

    Lindsay C. Shuller-Nickles

    2014-07-01

    Full Text Available Incorporation reactions play an important role in dictating immobilization and release pathways for chemical species in low-temperature geologic environments. Quantum-mechanical investigations of incorporation seek to characterize the stability and geometry of incorporated structures, as well as the thermodynamics and kinetics of the reactions themselves. For a thermodynamic treatment of incorporation reactions, a source of the incorporated ion and a sink for the released ion is necessary. These sources/sinks in a real geochemical system can be solids, but more commonly, they are charged aqueous species. In this contribution, we review the current methods for ab initio calculations of incorporation reactions, many of which do not consider incorporation from aqueous species. We detail a recently-developed approach for the calculation of incorporation reactions and expand on the part that is modeling the interaction of periodic solids with aqueous source and sink phases and present new research using this approach. To model these interactions, a systematic series of calculations must be done to transform periodic solid source and sink phases to aqueous-phase clusters. Examples of this process are provided for three case studies: (1 neptunyl incorporation into studtite and boltwoodite: for the layered boltwoodite, the incorporation energies are smaller (more favorable for reactions using environmentally relevant source and sink phases (i.e., ΔErxn(oxides > ΔErxn(silicates > ΔErxn(aqueous. Estimates of the solid-solution behavior of Np5+/P5+- and U6+/Si4+-boltwoodite and Np5+/Ca2+- and U6+/K+-boltwoodite solid solutions are used to predict the limit of Np-incorporation into boltwoodite (172 and 768 ppm at 300 °C, respectively; (2 uranyl and neptunyl incorporation into carbonates and sulfates: for both carbonates and sulfates, it was found that actinyl incorporation into a defect site is more favorable than incorporation into defect-free periodic

  5. Incorporating Floating Surface Objects into a Fully Dispersive Surface Wave Model

    Science.gov (United States)

    2016-04-19

    Decimation and Interpolation (PDI) Method was dded to NHWAVE by Shi et al. (2015) , who confirmed that the dy- amic pressure can be modeled accurately... cluster Farber located at he University of Delaware. Using 48 cores, it took about 8 h for a imulation of 10 0 0 s. The 10 m water depth was selected to re... decimation and interpolation (PDI) method for a baroclinic non-hydrostatic model. Ocean Mod. 96, 265–279 . 26 M.D. Orzech et al. / Ocean Modelling 102 (2016

  6. Influence of the growth-surface on the incorporation of phosphorus in SiC

    International Nuclear Information System (INIS)

    Rauls, E.; Gerstmann, U.; Frauenheim, Th.

    2005-01-01

    Phosphorus is a common and desired n-type dopant of SiC, but it turned out that doping by diffusion or during growth is rarely successful. To avoid the efforts and the creation of damage if ion implantation is used instead, these techniques were, though, highly desirable. In this work, we have investigated theoretically the experimental observation that phosphorus obviously hardly diffuses into the material. Not the diffusivity of the dopant but its addiction to occupy a three-fold coordinated surface site are critical, together with the way the surface affects the bulk migration barriers of the dopants. Whereas the most common growth direction for 4H-SiC, the polar silicon terminated (0001) surface, seems to be least appropriate for the incorporation of phosphorus atoms, growth along the nonpolar [112-bar 0] provides a good possibility to achieve efficient P-doping during growth

  7. Antibacterial and microstructure properties of titanium surfaces modified with Ag-incorporated nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guangzhong; Cheng, Li [State Key Laboratory of Porous Metal Materials, Northwest Institute for Nonferrous Metal Research (China); Yang, Hui-lin [Department of Orthopaedics, Wuxi People' s Hospital, Nanjing Medical University, Jiangsu Province (China); Zhao, Quan-ming, E-mail: abc8385@163.com [Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou (China)

    2016-07-15

    Although titanium (Ti) and its alloys have been widely used as implants in clinical settings, failures still occur mainly due to poor bioactivity and implant-associated infections. Here, we coated Ti implants with TiO{sub 2} nanotubes (TNTs) incorporated with the antibacterial agent Ag to produce Ag-TNTs, through anodization in AgNO{sub 3} and xenon light irradiation. We characterized surface morphology and composition of the coating with scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. We investigated surface topography of the coatings by atomic force microscopy (AFM) operated in the tapping mode. The results indicate that Ag was successfully doped onto the TNTs, and that the nanoparticles were mainly distributed on the surface of TNTs. Finally, our antibacterial experiments reveal that Ag-TNTs on Ti implants exhibit excellent antibacterial activities, which promises to have significant clinical applications as implants. (author)

  8. METHODS TO DEVELOP A TOROIDAL SURFACE

    Directory of Open Access Journals (Sweden)

    DANAILA Ligia

    2017-05-01

    Full Text Available The paper work presents two practical methods to draw the development of a surface unable to be developed applying classical methods of Descriptive Geometry, the toroidal surface, frequently met in technical practice. The described methods are approximate ones; the development is obtained with the help of points. The accuracy of the methods is given by the number of points used when drawing. As for any other approximate method, when practically manufactured the development may need to be adjusted on site.

  9. First-principles study of Mg incorporation at wurtzite InN (0 0 0 1) and (0001-bar) surfaces

    International Nuclear Information System (INIS)

    Ding, S.F.; Qu, X.P.; Fan, G.H.

    2009-01-01

    In this article we investigate the energetics of Mg adsorption and incorporation at the InN(0 0 0 1) and InN(0001-bar) surfaces by the method of total energy plane-wave expansions with ultra-soft pseudo potential technology based on the density functional theory (DFT) in the generalized approximation (GGA). It is found that for a 1/4 monolayer (ML) coverage of the InN(0 0 0 1) surface, Mg atoms preferentially adsorb at the bridge sites and T4 sites, but they are unstable when compared with Mg incorporated in the first three layers. For a 1/4 ML coverage of the InN(0001-bar) surface, Mg atoms preferentially adsorb at the H3 sites with the formation energy of -3.49 (eV/(2x2) supercell), which is lower than that of the T4 sites, and the formation energy increases with increasing magnesium coverage. Further study shows that the formation energy for Mg atom is lower than that of In atom, which indicates that magnesium adsorption is more favorable in these conditions.

  10. Scanning Electron Microscope (SEM) Evaluation of the Interface between a Nanostructured Calcium-Incorporated Dental Implant Surface and the Human Bone.

    Science.gov (United States)

    Mangano, Francesco; Raspanti, Mario; Maghaireh, Hassan; Mangano, Carlo

    2017-12-17

    Purpose . The aim of this scanning electron microscope (SEM) study was to investigate the interface between the bone and a novel nanostructured calcium-incorporated dental implant surface in humans. Methods . A dental implant (Anyridge ® , Megagen Implant Co., Gyeongbuk, South Korea) with a nanostructured calcium-incorporated surface (Xpeed ® , Megagen Implant Co., Gyeongbuk, South Korea), which had been placed a month earlier in a fully healed site of the posterior maxilla (#14) of a 48-year-old female patient, and which had been subjected to immediate functional loading, was removed after a traumatic injury. Despite the violent trauma that caused mobilization of the fixture, its surface appeared to be covered by a firmly attached, intact tissue; therefore, it was subjected to SEM examination. The implant surface of an unused nanostructured calcium-incorporated implant was also observed under SEM, as control. Results . The surface of the unused implant showed a highly-structured texture, carved by irregular, multi-scale hollows reminiscent of a fractal structure. It appeared perfectly clean and devoid of any contamination. The human specimen showed trabecular bone firmly anchored to the implant surface, bridging the screw threads and filling the spaces among them. Conclusions . Within the limits of this human histological report, the sample analyzed showed that the nanostructured calcium-incorporated surface was covered by new bone, one month after placement in the posterior maxilla, under an immediate functional loading protocol.

  11. Analysis of nonlinear vibrations and stability of rotating asymmetrical nano-shafts incorporating surface energy effects

    Science.gov (United States)

    Ghodousi, Maryam; Shahgholi, Majid; Payganeh, Gholamhassan

    2018-03-01

    The objective of the present work is to investigate the nonlinear vibrations of the rotating asymmetrical nano-shafts by considering surface effect. In order to compute the surface stress tensor, the surface elasticity theory is used. The governing nonlinear equations of motion are obtained with the aid of variational approach. Bubnov-Galerkin is a very effective method for exploiting the reduced-order model of the equations of motion. The averaging method is employed to analyze the reduced-order model of the system. For this purpose, the well-known Van der Pol transformation in the complex form and angle-action transformation are utilized. The effect of surface stress on the forward and backward speeds, steady state responses of the system, fixed points, close orbits and stability of the solutions is examined. The preliminary results of the research show that the absolute values of forward and backward whirling speeds in the presence of surface effect with positive residual surface stress are higher than those of regarding the system without surface effect and in the presence of surface effect with negative residual surface stress. In addition, it is seen that the undamped rotating asymmetrical nano-shaft, for specified value of detuning parameter, in the absence or presence of surface effect has various number of stable and unstable periodic solutions. Besides, there is different number of separatrix (homoclinic orbit type). Furthermore, bifurcations, number of solutions and their stability for damped rotating asymmetrical nano-shaft are investigated. Also, the above results have been obtained for rotating symmetrical nano-shaft.

  12. Effects on cytotoxicity and antibacterial properties of the incorporations of silver nanoparticles into the surface coating of dental alloys.

    Science.gov (United States)

    Shen, Xiao-Ting; Zhang, Yan-Zhen; Xiao, Fang; Zhu, Jing; Zheng, Xiao-Dong

    2017-07-01

    The aim of this study was to research the changes in cytotoxicity and antibacterial properties after silver nanoparticles (AgNPs) were incorporated into the surface coating of dental alloys. AgNPs were attached to cobalt chromium alloys and pure titanium using a hydrothermal method, according to the reaction: AgNO 3 +NaBH 4 → Ag+1/2H 2 +1/2B 2 H 6 +NaNO 3 . A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate the cytotoxicity of the alloys when in contact with osteogenic precursor cells (MC3T3-E1) from mice and mesenchymal stem cells (BMSC) from rats. The antibacterial properties of dental alloys incorporating three different concentrations (10, 4, and 2 μmol/L) of AgNPs were tested on Staphylococcus aureus (SA) and Streptococcus mutans (MS). High cytotoxicity values were observed for all dental alloys that contained 0% of AgNPs (the control groups). The incorporation of AgNPs reduced cytotoxicity values. No significant difference was observed for antibacterial performance when comparing dental alloys containing AgNPs to the respective control groups. The results demonstrated that the cobalt chromium alloys and pure titanium all had cytotoxicity to MC3T3-E1 and BMSC and that the incorporation of AgNPs could reduce this cytotoxicity. The concentrations of AgNPs adopted in this study were found to have no antibacterial action against SA or MS.

  13. Method to incorporate anisotropic semiconductor nanocrystals of all shapes in an ultrathin and uniform silica shell

    NARCIS (Netherlands)

    Hutter, Eline M.; Pietra, Francesca; Moes, Relinde; Mitoraj, Dariusz; Meeldijk, Johannes D.; De Mello Donegá, Celso; Vanmaekelbergh, Daniël

    2014-01-01

    In this work, we present a method for the incorporation of anisotropic colloidal nanocrystals of many different shapes in silica in a highly controlled way. This method yields a uniform silica shell, with thickness tunable from 3 to 17 nm. The silica shell perfectly adapts to the shape of the

  14. An Enzymatic Clinical Chemistry Laboratory Experiment Incorporating an Introduction to Mathematical Method Comparison Techniques

    Science.gov (United States)

    Duxbury, Mark

    2004-01-01

    An enzymatic laboratory experiment based on the analysis of serum is described that is suitable for students of clinical chemistry. The experiment incorporates an introduction to mathematical method-comparison techniques in which three different clinical glucose analysis methods are compared using linear regression and Bland-Altman difference…

  15. Methods of decontaminating surfaces and related compositions

    Science.gov (United States)

    Demmer, Ricky L.; Crosby, Daniel; Norton, Christopher J.

    2016-11-22

    A composition of matter includes water, at least one acid, at least one surfactant, at least one fluoride salt, and ammonium nitrate. A method of decontaminating a surface includes exposing a surface to such a composition and removing the composition from the surface. Other compositions of matter include water, a fatty alcohol ether sulfate, nitrilotriacetic acid, at least one of hydrochloric acid and nitric acid, sodium fluoride, potassium fluoride, ammonium nitrate, and gelatin.

  16. XPS study of PBO fiber surface modified by incorporation of hydroxyl polar groups in main chains

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Tao; Hu Dayong; Jin Junhong; Yang Shenglin [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Li Guang, E-mail: lig@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Jiang Jianming [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China)

    2010-01-15

    Dihydroxy poly(p-phenylene benzobisoxazole) (DHPBO), a modified poly(p-phenylene benzoxazole) (PBO) polymer containing double hydroxyl groups in polymer chains, was synthesized by copolymerization of 4,6-diamino resorcinol dihydrochloride (DAR), purified terephthalic acid (TA) and 2,5-dihydroxyterephthalic acid (DHTA). DHPBO fibers were prepared by dry-jet wet-spinning method. The effects of hydroxyl polar groups on the surface elemental compositions of PBO fiber were investigated by X-ray photoelectron spectroscopy (XPS). The results show that the ratio of oxygen/carbon on the surface of DHPBO fibers is higher than that on the surface of PBO fibers, which indicates the content of polar groups on the surface of DHPBO fiber increase compared with PBO fiber.

  17. Polymer incorporation method affects the physical stability of amorphous indomethacin in aqueous suspension

    DEFF Research Database (Denmark)

    Surwase, S A; Itkonen, L; Aaltonen, J

    2015-01-01

    methylcellulose (HPMC) and Soluplus® (SP)) were used and included in the suspensions either as a solid dispersion (SD) with IND or dissolved in the suspension medium prior to the addition of amorphous IND. The total concentrations of both IND and the polymer in the suspensions were kept the same for both methods......This study reports the potential of different polymers and polymer incorporation methods to inhibit crystallisation and maintain supersaturation of amorphous indomethacin (IND) in aqueous suspensions during storage. Three different polymers (poly(vinyl pyrrolidone) (PVP), hydroxypropyl...... of polymer incorporation. All the polymers (with both incorporation methods) inhibited crystallisation of the amorphous IND. The SDs were better than the predissolved polymer solutions at inhibiting crystallisation. The SDs were also better at maintaining drug supersaturation. SP showed a higher IND...

  18. Monte Carlo method for random surfaces

    International Nuclear Information System (INIS)

    Berg, B.

    1985-01-01

    Previously two of the authors proposed a Monte Carlo method for sampling statistical ensembles of random walks and surfaces with a Boltzmann probabilistic weight. In the present paper we work out the details for several models of random surfaces, defined on d-dimensional hypercubic lattices. (orig.)

  19. Surface physics theoretical models and experimental methods

    CERN Document Server

    Mamonova, Marina V; Prudnikova, I A

    2016-01-01

    The demands of production, such as thin films in microelectronics, rely on consideration of factors influencing the interaction of dissimilar materials that make contact with their surfaces. Bond formation between surface layers of dissimilar condensed solids-termed adhesion-depends on the nature of the contacting bodies. Thus, it is necessary to determine the characteristics of adhesion interaction of different materials from both applied and fundamental perspectives of surface phenomena. Given the difficulty in obtaining reliable experimental values of the adhesion strength of coatings, the theoretical approach to determining adhesion characteristics becomes more important. Surface Physics: Theoretical Models and Experimental Methods presents straightforward and efficient approaches and methods developed by the authors that enable the calculation of surface and adhesion characteristics for a wide range of materials: metals, alloys, semiconductors, and complex compounds. The authors compare results from the ...

  20. SPACE CHARGE SIMULATION METHODS INCORPORATED IN SOME MULTI - PARTICLE TRACKING CODES AND THEIR RESULTS COMPARISON

    International Nuclear Information System (INIS)

    BEEBE - WANG, J.; LUCCIO, A.U.; D IMPERIO, N.; MACHIDA, S.

    2002-01-01

    Space charge in high intensity beams is an important issue in accelerator physics. Due to the complicity of the problems, the most effective way of investigating its effect is by computer simulations. In the resent years, many space charge simulation methods have been developed and incorporated in various 2D or 3D multi-particle-tracking codes. It has becoming necessary to benchmark these methods against each other, and against experimental results. As a part of global effort, we present our initial comparison of the space charge methods incorporated in simulation codes ORBIT++, ORBIT and SIMPSONS. In this paper, the methods included in these codes are overviewed. The simulation results are presented and compared. Finally, from this study, the advantages and disadvantages of each method are discussed

  1. Generalised empirical method for predicting surface subsidence

    International Nuclear Information System (INIS)

    Zhang, M.; Bhattacharyya, A.K.

    1994-01-01

    Based on a simplified strata parameter, i.e. the ratio of total thickness of the strong rock beds in an overburden to the overall thickness of the overburden, a Generalised Empirical Method (GEM) is described for predicting the maximum subsidence and the shape of a complete transverse subsidence profile due to a single completely extracted longwall panel. In the method, a nomogram for predicting the maximum surface subsidence is first developed from the data collected from subsidence measurements worldwide. Then, a method is developed for predicting the shapes of complete transfer subsidence profiles for a horizontal seam and ground surface and is verified by case studies. 13 refs., 9 figs., 2 tabs

  2. Leaching of Heavy Metals Using SPLP Method from Fired Clay Brick Incorporating with Sewage Sludge

    Science.gov (United States)

    Kadir, Aeslina Abdul; Salim, Nurul Salhana Abdul; Amira Sarani, Noor; Aqma Izurin Rahmat, Nur

    2017-05-01

    Sewage sludge is a by-product generate from wastewater treatment process. The sewage sludge contains significant trace metal such as Cr, Mn, Ni, Cu, Zn, As, Cd and Pb which are toxic to the environment. Sewage sludge is disposed of by landfilling method. However, this option not suitable because of land restriction and environmental control regulations imposed. Therefore, sewage sludge from wastewater treatment plant was incorporated into fired clay brick to produce good quality of brick as well as reducing heavy metals from sludge itself. Sewage sludge with 0%, 1%, 5%, 10% and 20% of were incorporated into fired clay bricks and fired at 1050°C temperature with heating rates of 1°C/min. The brick sample then crushed and sieved through 9.5 mm sieve for Synthetic Precipitation Leaching Procedure (SPLP). From the results, incorporation up to 20% of sewage sludge has leached less heavy metals and compliance with USEPA standard.

  3. Enhanced Sensitivity of Surface Acoustic Wave-Based Rate Sensors Incorporating Metallic Dot Arrays

    Directory of Open Access Journals (Sweden)

    Wen Wang

    2014-02-01

    Full Text Available A new surface acoustic wave (SAW-based rate sensor pattern incorporating metallic dot arrays was developed in this paper. Two parallel SAW delay lines with a reverse direction and an operation frequency of 80 MHz on a same X-112°Y LiTaO3 wafer are fabricated as the feedback of two SAW oscillators, and mixed oscillation frequency was used to characterize the external rotation. To enhance the Coriolis force effect acting on the SAW propagation, a copper (Cu dot array was deposited along the SAW propagation path of the SAW devices. The approach of partial-wave analysis in layered media was referred to analyze the response mechanisms of the SAW based rate sensor, resulting in determination of the optimal design parameters. To improve the frequency stability of the oscillator, the single phase unidirectional transducers (SPUDTs and combed transducer were used to form the SAW device to minimize the insertion loss and accomplish the single mode selection, respectively. Excellent long-term (measured in hours frequency stability of 0.1 ppm/h was obtained. Using the rate table with high precision, the performance of the developed SAW rate sensor was evaluated experimentally; satisfactory detection sensitivity (16.7 Hz∙deg∙s−1 and good linearity were observed.

  4. A fast beam hardening correction method incorporated in a filtered back-projection based MAP algorithm

    Science.gov (United States)

    Luo, Shouhua; Wu, Huazhen; Sun, Yi; Li, Jing; Li, Guang; Gu, Ning

    2017-03-01

    The beam hardening effect can induce strong artifacts in CT images, which result in severely deteriorated image quality with incorrect intensities (CT numbers). This paper develops an effective and efficient beam hardening correction algorithm incorporated in a filtered back-projection based maximum a posteriori (BHC-FMAP). In the proposed algorithm, the beam hardening effect is modeled and incorporated into the forward-projection of the MAP to suppress beam hardening induced artifacts, and the image update process is performed by Feldkamp-Davis-Kress method based back-projection to speed up the convergence. The proposed BHC-FMAP approach does not require information about the beam spectrum or the material properties, or any additional segmentation operation. The proposed method was qualitatively and quantitatively evaluated using both phantom and animal projection data. The experimental results demonstrate that the BHC-FMAP method can efficiently provide a good correction of beam hardening induced artefacts.

  5. Investigation of structural transformations in surface layer of phosphate glasses incorporating radiactive wastes

    International Nuclear Information System (INIS)

    Aloj, A.S.; Kolycheva, T.I.; Trofimenko, A.V.; Shashukov, E.A.

    1985-01-01

    The objective of the paper was to clarify possibilities of detection of structural transformations initial stages on the surface of phosphate glasses using the method of infrared reflection spectroscopy. Phase composition of crystalline compounds formed in surface glass layer is determined by the method of X-ray diffraction. All experiments were performed using sodium alumophosphate glass comprising the model mixture of fission product of the following compostion (mass%): Na 2 O-22.0, Al 2 O 3 -14.0, P 2 O 5 -50.0, Fe 2 O 3 -3.5, Cs 2 O-3.5, SrO-3.0, Ln 2 O 3 -4.0, where Ln 2 O 3 is a mixture of cerium, lanthanum and europium oxides. Sample preparation were carried out by molten glass deposition on platinum forms 15mm in diameter and 4mm thick. Glasses were treated within the 600-400deg.C temperature range. Fixing of processes accompanied by structural transformations was accomplished the method of rapid cooling. It has been shown that phase transformations, taking place in investigated phosphate glasses under the action of heat, result in deterioration of chemical properties. Analysis of IR spectra has revealed that emergence of structural transformations in surface layer of investigated glasses results in variation of a ratio of 1060 and 1140cm - 1 reflection band intensities. Experimental dependences of the time of beginning of variation of 1060 and 1140cm - 1 bands relative intensity on temperature are presented. Insemilogarithmic coordinates this dependence has a straight line form within the 600-400 deg C temperature range and is desc ribed by the following formular: lg r=-7.41+5.70x10 3 x1/T, where r is the time of process beginning, h. Extrapolation of established to the region of low temperature is shown. Competence of such extrapolation may be confirmed in the course of further experiments

  6. A strontium-incorporated nanoporous titanium implant surface for rapid osseointegration

    Science.gov (United States)

    Zhang, Wenjie; Cao, Huiliang; Zhang, Xiaochen; Li, Guanglong; Chang, Qing; Zhao, Jun; Qiao, Yuqin; Ding, Xun; Yang, Guangzheng; Liu, Xuanyong; Jiang, Xinquan

    2016-02-01

    Rapid osseointegration of dental implants will shorten the period of treatment and enhance the comfort of patients. Due to the vital role of angiogenesis played during bone development and regeneration, it might be feasible to promote rapid osseointegration by modifying the implant surface to gain a combined angiogenesis/osteogenesis inducing capacity. In this study, a novel coating (MAO-Sr) with strontium-incorporated nanoporous structures on titanium implants was generated via a new micro-arc oxidation, in an attempt to induce angiogenesis and osteogenesis to enhance rapid osseointegration. In vitro, the nanoporous structure significantly enhanced the initial adhesion of canine BMSCs. More importantly, sustained release of strontium ions also displayed a stronger effect on the BMSCs in facilitating their osteogenic differentiation and promoting the angiogenic growth factor secretion to recruit endothelial cells and promote blood vessel formation. Advanced mechanism analyses indicated that MAPK/Erk and PI3K/Akt signaling pathways were involved in these effects of the MAO-Sr coating. Finally, in the canine dental implantation study, the MAO-Sr coating induced faster bone formation within the initial six weeks and the osseointegration effect was comparable to that of the commercially available ITI implants. These results suggest that the MAO-Sr coating has the potential for future use in dental implants.Rapid osseointegration of dental implants will shorten the period of treatment and enhance the comfort of patients. Due to the vital role of angiogenesis played during bone development and regeneration, it might be feasible to promote rapid osseointegration by modifying the implant surface to gain a combined angiogenesis/osteogenesis inducing capacity. In this study, a novel coating (MAO-Sr) with strontium-incorporated nanoporous structures on titanium implants was generated via a new micro-arc oxidation, in an attempt to induce angiogenesis and osteogenesis to

  7. Blue-Emitting Small Silica Particles Incorporating ZnSe-Based Nanocrystals Prepared by Reverse Micelle Method

    Directory of Open Access Journals (Sweden)

    Masanori Ando

    2007-01-01

    Full Text Available ZnSe-based nanocrystals (ca. 4-5 nm in diameter emitting in blue region (ca. 445 nm were incorporated in spherical small silica particles (20–40 nm in diameter by a reverse micelle method. During the preparation, alkaline solution was used to deposit the hydrolyzed alkoxide on the surface of nanocrystals. It was crucially important for this solution to include Zn2+ ions and surfactant molecules (thioglycolic acid to preserve the spectral properties of the final silica particles. This is because these substances in the solution prevent the surface of nanocrystals from deterioration by dissolution during processing. The resultant silica particles have an emission efficiency of 16% with maintaining the photoluminescent spectral width and peak wavelength of the initial colloidal solution.

  8. The comparison of antimicrobial packaging properties with different applications incorporation method of active material

    Science.gov (United States)

    Anwar, R. W.; Sugiarto; Warsiki, E.

    2018-03-01

    Contamination after the processing of products during storage, distribution and marketing is one of the main causes of food safety issues. Handling of food products after processing can be done during the packaging process. Antimicrobial (AM) active packaging is one of the concept of packaging product development by utilize the interaction between the product and the packaging environment that can delay the bacterial damage by killing or reducing bacterial growth. The active system is formed by incorporating an antimicrobial agent against a packaging matrix that will function as a carrier. Many incorporation methods have been developed in this packaging-making concept which were direct mixing, polishing, and encapsulation. The aims of this research were to examine the different of the AM packaging performances including its stability and effectiveness of its function that would be produced by three different methods. The stability of the packaging function was analyzed by looking at the diffusivity of the active ingredient to the matrix using SEM. The effectiveness was analyzed by the ability of the packaging to prevent the growing of the microbial. The results showed that different incorporation methods resulted on different characteristics of the AM packaging.

  9. A novel method incorporating gene ontology information for unsupervised clustering and feature selection.

    Directory of Open Access Journals (Sweden)

    Shireesh Srivastava

    Full Text Available Among the primary goals of microarray analysis is the identification of genes that could distinguish between different phenotypes (feature selection. Previous studies indicate that incorporating prior information of the genes' function could help identify physiologically relevant features. However, current methods that incorporate prior functional information do not provide a relative estimate of the effect of different genes on the biological processes of interest.Here, we present a method that integrates gene ontology (GO information and expression data using Bayesian regression mixture models to perform unsupervised clustering of the samples and identify physiologically relevant discriminating features. As a model application, the method was applied to identify the genes that play a role in the cytotoxic responses of human hepatoblastoma cell line (HepG2 to saturated fatty acid (SFA and tumor necrosis factor (TNF-alpha, as compared to the non-toxic response to the unsaturated FFAs (UFA and TNF-alpha. Incorporation of prior knowledge led to a better discrimination of the toxic phenotypes from the others. The model identified roles of lysosomal ATPases and adenylate cyclase (AC9 in the toxicity of palmitate. To validate the role of AC in palmitate-treated cells, we measured the intracellular levels of cyclic AMP (cAMP. The cAMP levels were found to be significantly reduced by palmitate treatment and not by the other FFAs, in accordance with the model selection of AC9.A framework is presented that incorporates prior ontology information, which helped to (a perform unsupervised clustering of the phenotypes, and (b identify the genes relevant to each cluster of phenotypes. We demonstrate the proposed framework by applying it to identify physiologically-relevant feature genes that conferred differential toxicity to saturated vs. unsaturated FFAs. The framework can be applied to other problems to efficiently integrate ontology information and

  10. Comparison of different pathways in metamorphic graded buffers on GaAs substrate: Indium incorporation with surface roughness

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rahul, E-mail: rkp203@gmail.com [Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur 721302 (India); Mukhopadhyay, P. [Rajendra Mishra School of Engineering Entrepreneurship, Indian Institute of Technology, Kharagpur 721302 (India); Bag, A.; Jana, S. Kr. [Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur 721302 (India); Chakraborty, A. [Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology, Kharagpur 721 302 (India); Das, S.; Mahata, M. Kr. [Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur 721302 (India); Biswas, D. [Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology, Kharagpur 721 302 (India)

    2015-01-01

    Highlights: • In(Al,Ga)As metamorphic buffers on GaAs have been grown. • Surface morphology, strain relaxation and compositional variation have been studied. • Al containing buffers shows inferior surface roughness. • Surface roughness modulates the indium incorporation rate. - Abstract: In this work, compositionally graded In(Al,Ga)As metamorphic buffers (MBs) on GaAs substrate have been grown by MBE through three different paths. A comparative study has been done to comprehend the effect of underlying MB on the constant composition InAlAs healing layer by analyzing the relaxation behaviour, composition and surface morphology of the grown structures. The compositional variation between the constant composition healing layers on top of graded MB has been observed in all three samples although the growth conditions have been kept same. Indium incorporation rate has been found to be dependent on underlying MB. By combining the result of atomic force microscopy, photo-luminescence and X-ray reciprocal space mapping, varying surface roughness has been proposed as the probable driving force behind different Indium incorporation rate.

  11. Comparison of different pathways in metamorphic graded buffers on GaAs substrate: Indium incorporation with surface roughness

    International Nuclear Information System (INIS)

    Kumar, Rahul; Mukhopadhyay, P.; Bag, A.; Jana, S. Kr.; Chakraborty, A.; Das, S.; Mahata, M. Kr.; Biswas, D.

    2015-01-01

    Highlights: • In(Al,Ga)As metamorphic buffers on GaAs have been grown. • Surface morphology, strain relaxation and compositional variation have been studied. • Al containing buffers shows inferior surface roughness. • Surface roughness modulates the indium incorporation rate. - Abstract: In this work, compositionally graded In(Al,Ga)As metamorphic buffers (MBs) on GaAs substrate have been grown by MBE through three different paths. A comparative study has been done to comprehend the effect of underlying MB on the constant composition InAlAs healing layer by analyzing the relaxation behaviour, composition and surface morphology of the grown structures. The compositional variation between the constant composition healing layers on top of graded MB has been observed in all three samples although the growth conditions have been kept same. Indium incorporation rate has been found to be dependent on underlying MB. By combining the result of atomic force microscopy, photo-luminescence and X-ray reciprocal space mapping, varying surface roughness has been proposed as the probable driving force behind different Indium incorporation rate

  12. An experimental method to determine the electrostatic field enhancement factor of a practical conductor surface

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson; Crichton, George C

    1989-01-01

    A method of determining the field enhancement factor of a practical conductor is presented. The method is developed from a modified theory of discharge onset in a gaseous medium. This modification incorporates the influence of conductor surface roughness. Onset data from an experimental study...... that utilized electrodes of varying surface roughness are examined, and the results obtained using the proposed method are discussed with reference to both the underlying theory and the practical aspects of the experimental measurements...

  13. Method for incorporation monitoring - Studies on measurement and interpretation of radionuclide excretion, particularly thorium decay products, via exhaled breath

    International Nuclear Information System (INIS)

    Anon

    1998-01-01

    The development and application of a measuring method is described for thorium incorporation monitoring by way of measuring Rn-220 (thoron) in exhaled breath. The method is intended for application to monitoring the incorporation of thorium by occupationally exposed persons in compliance with the regulatory guide on health physics monitoring for determination of whole-body dose. (orig./CB) [de

  14. Fixed Full Arches Supported by Tapered Implants with Knife-Edge Thread Design and Nanostructured, Calcium-Incorporated Surface: A Short-Term Prospective Clinical Study

    Directory of Open Access Journals (Sweden)

    Soheil Bechara

    2017-01-01

    Full Text Available Purpose. To evaluate implant survival, peri-implant bone loss, and complications affecting fixed full-arch (FFA restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface. Methods. Between January 2013 and December 2015, all patients referred for implant-supported FFA restorations were considered for enrollment in this study. All patients received implants with a knife-edge thread design and nanostructured calcium-incorporated surface (Anyridge®, Megagen, South Korea were restored with FFA restorations and enrolled in a recall program. The final outcomes were implant survival, peri-implant bone loss, biologic/prosthetic complications, and “complication-free” survival of restorations. Results. Twenty-four patients were selected. Overall, 215 implants were inserted (130 maxilla, 85 mandible, 144 in extraction sockets and 71 in healed ridges. Thirty-six FFAs were delivered (21 maxilla, 15 mandible: 27 were immediately loaded and 9 were conventionally loaded. The follow-up ranged from 1 to 3 years. Two fixtures failed, yielding an implant survival rate of 95.9% (patient-based. A few complications were registered, for a “complication-free” survival of restorations of 88.9%. Conclusions. FFA restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface are successful in the short term, with high survival and low complication rates; long-term studies are needed to confirm these outcomes.

  15. Fixed Full Arches Supported by Tapered Implants with Knife-Edge Thread Design and Nanostructured, Calcium-Incorporated Surface: A Short-Term Prospective Clinical Study

    Science.gov (United States)

    Bechara, Soheil; Lukosiunas, Algirdas; Kubilius, Ricardas

    2017-01-01

    Purpose. To evaluate implant survival, peri-implant bone loss, and complications affecting fixed full-arch (FFA) restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface. Methods. Between January 2013 and December 2015, all patients referred for implant-supported FFA restorations were considered for enrollment in this study. All patients received implants with a knife-edge thread design and nanostructured calcium-incorporated surface (Anyridge®, Megagen, South Korea) were restored with FFA restorations and enrolled in a recall program. The final outcomes were implant survival, peri-implant bone loss, biologic/prosthetic complications, and “complication-free” survival of restorations. Results. Twenty-four patients were selected. Overall, 215 implants were inserted (130 maxilla, 85 mandible), 144 in extraction sockets and 71 in healed ridges. Thirty-six FFAs were delivered (21 maxilla, 15 mandible): 27 were immediately loaded and 9 were conventionally loaded. The follow-up ranged from 1 to 3 years. Two fixtures failed, yielding an implant survival rate of 95.9% (patient-based). A few complications were registered, for a “complication-free” survival of restorations of 88.9%. Conclusions. FFA restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface are successful in the short term, with high survival and low complication rates; long-term studies are needed to confirm these outcomes. PMID:28246595

  16. Mass Sensitivity Optimization of a Surface Acoustic Wave Sensor Incorporating a Resonator Configuration

    Directory of Open Access Journals (Sweden)

    Wenchang Hao

    2016-04-01

    Full Text Available The effect of the sensitive area of the two-port resonator configuration on the mass sensitivity of a Rayleigh surface acoustic wave (R-SAW sensor was investigated theoretically, and verified in experiments. A theoretical model utilizing a 3-dimensional finite element method (FEM approach was established to extract the coupling-of-modes (COM parameters in the absence and presence of mass loading covering the electrode structures. The COM model was used to simulate the frequency response of an R-SAW resonator by a P-matrix cascading technique. Cascading the P-matrixes of unloaded areas with mass loaded areas, the sensitivity for different sensitive areas was obtained by analyzing the frequency shift. The performance of the sensitivity analysis was confirmed by the measured responses from the silicon dioxide (SiO2 deposited on different sensitive areas of R-SAW resonators. It is shown that the mass sensitivity varies strongly for different sensitive areas, and the optimal sensitive area lies towards the center of the device.

  17. Improvement of epoxy resin properties by incorporation of TiO2 nanoparticles surface modified with gallic acid esters

    International Nuclear Information System (INIS)

    Radoman, Tijana S.; Džunuzović, Jasna V.; Jeremić, Katarina B.; Grgur, Branimir N.; Miličević, Dejan S.; Popović, Ivanka G.; Džunuzović, Enis S.

    2014-01-01

    Highlights: • Nanocomposites of epoxy resin and TiO 2 nanoparticles surface modified with gallates. • The T g of epoxy resin was increased by incorporation of surface modified TiO 2 . • WVTR of epoxy resin decreased in the presence of surface modified TiO 2 nanoparticles. • WVTR of nanocomposites was reduced with increasing gallates hydrophobic chain length. • Modified TiO 2 nanoparticles react as oxygen scavengers, inhibiting steel corrosion. - Abstract: Epoxy resin/titanium dioxide (epoxy/TiO 2 ) nanocomposites were obtained by incorporation of TiO 2 nanoparticles surface modified with gallic acid esters in epoxy resin. TiO 2 nanoparticles were obtained by acid catalyzed hydrolysis of titanium isopropoxide and their structural characterization was performed by X-ray diffraction and transmission electron microscopy. Three gallic acid esters, having different hydrophobic part, were used for surface modification of the synthesized TiO 2 nanoparticles: propyl, hexyl and lauryl gallate. The gallate chemisorption onto surface of TiO 2 nanoparticles was confirmed by Fourier transform infrared and ultraviolet–visible spectroscopy, while the amount of surface-bonded gallates was determined using thermogravimetric analysis. The influence of the surface modified TiO 2 nanoparticles, as well as the length of hydrophobic part of the gallate used for surface modification of TiO 2 nanoparticles, on glass transition temperature, barrier, dielectric and anticorrosive properties of epoxy resin was investigated by differential scanning calorimetry, water vapor transmission test, dielectric spectroscopy, electrochemical impedance spectroscopy and polarization measurements. Incorporation of surface modified TiO 2 nanoparticles in epoxy resin caused increase of glass transition temperature and decrease of the water vapor permeability of epoxy resin. The water vapor transmission rate of epoxy/TiO 2 nanocomposites was reduced with increasing hydrophobic part chain length of

  18. Incorporating denitrification-decomposition method to estimate field emissions for Life Cycle Assessment.

    Science.gov (United States)

    Deng, Yelin; Paraskevas, Dimos; Cao, Shi-Jie

    2017-09-01

    This study focuses on a detailed Life Cycle Assessment (LCA) for flax cultivation in Northern France. Nitrogen related field emissions are derived both from a process-oriented DeNitrification-DeComposition (DNDC) method and the generic Intergovernmental Panel on Climate Change (IPCC) method. Since the IPCC method is synthesised from field measurements at sites with various soil types, climate conditions, and crops, it contains significant uncertainties. In contrast, the outputs from the DNDC method are considered as more site specific as it is built according to complex models of soil science. As it is demonstrated in this paper the emission factors from the DNDC method and the recommended values from the IPCC method exhibit significant variations for the case of flax cultivation. The DNDC based emission factor for direct N 2 O emission, which is a strong greenhouse gas, is 0.25-0.5%, significantly lower than the recommend 1% level derived from the IPCC method. The DNDC method leads to a reduction of 17% in the impact category of climate change per kg retted flax straw production from the level obtained from the IPCC method. Much higher reductions are recorded for particulate matter formation, terrestrial acidification, and marine eutrophication impact categories. Meanwhile, based on the DNDC and IPCC methods, a comparative LCA per kg flax straw is presented. For both methods sensitivity analysis as well as comparison of uncertainties parameterisation of the N 2 O estimates via Monte-Carlo analysis are performed. The DNDC method incorporates more relevant field emissions from the agricultural life cycle phase, which can also improve the quality of the Life Cycle Inventory as well as allow more precise uncertainty calibration in the LCA inventory. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Projector Augmented Wave Method Incorporated into Gauss-Type Atomic Orbital Based Density Functional Theory.

    Science.gov (United States)

    Xiong, Xiao-Gen; Yanai, Takeshi

    2017-07-11

    The Projector Augmented Wave (PAW) method developed by Blöchl is well recognized as an efficient, accurate pseudopotential approach in solid-state density functional theory (DFT) calculations with the plane-wave basis. Here we present an approach to incorporate the PAW method into the Gauss-type function (GTF) based DFT implementation, which is widely used for molecular quantum chemistry calculations. The nodal and high-exponent GTF components of valence molecular orbitals (MOs) are removed or pseudized by the ultrasoft PAW treatment, while there is elaborate transparency to construct an accurate and well-controlled pseudopotential from all-electron atomic description and to reconstruct an all-electron form of valence MOs from the pseudo MOs. The smoothness of the pseudo MOs should benefit the efficiency of GTF-based DFT calculations in terms of elimination of high-exponent primitive GTFs and reduction of grid points in the numerical quadrature. The processes of the PAW method are divided into basis-independent and -dependent parts. The former is carried out using the previously developed PAW libraries libpaw and atompaw. The present scheme is implemented by incorporating libpaw into the conventional GTF-based DFT solver. The details of the formulations and implementations of GTF-related PAW procedures are presented. The test calculations are shown for illustrating the performance. With the near-complete GTF basis at the cc-pVQZ level, the total energies obtained using our PAW method with suited frozen core treatments converge to those with the conventional all-electron GTF-based method with a rather small absolute error.

  20. Plasmonic nanostructures for surface enhanced spectroscopic methods.

    Science.gov (United States)

    Jahn, Martin; Patze, Sophie; Hidi, Izabella J; Knipper, Richard; Radu, Andreea I; Mühlig, Anna; Yüksel, Sezin; Peksa, Vlastimil; Weber, Karina; Mayerhöfer, Thomas; Cialla-May, Dana; Popp, Jürgen

    2016-02-07

    A comprehensive review of theoretical approaches to simulate plasmonic-active metallic nano-arrangements is given. Further, various fabrication methods based on bottom-up, self-organization and top-down techniques are introduced. Here, analytical approaches are discussed to investigate the optical properties of isotropic and non-magnetic spherical or spheroidal particles. Furthermore, numerical methods are introduced to research complex shaped structures. A huge variety of fabrication methods are reviewed, e.g. bottom-up preparation strategies for plasmonic nanostructures to generate metal colloids and core-shell particles as well as complex-shaped structures, self-organization as well as template-based methods and finally, top-down processes, e.g. electron beam lithography and its variants as well as nanoimprinting. The review article is aimed at beginners in the field of surface enhanced spectroscopy (SES) techniques and readers who have a general interest in theoretical modelling of plasmonic substrates for SES applications as well as in the fabrication of the desired structures based on methods of the current state of the art.

  1. Structure and performance of polymer-derived bulk ceramics determined by method of filler incorporation

    Science.gov (United States)

    Konegger, T.; Schneider, P.; Bauer, V.; Amsüss, A.; Liersch, A.

    2013-12-01

    The effect of four distinct methods of incorporating fillers into a preceramic polymer matrix was investigated with respect to the structural and mechanical properties of the resulting materials. Investigations were conducted with a polysiloxane/Al2O3/ZrO2 model system used as a precursor for mullite/ZrO2 composites. A quantitative evaluation of the uniformity of filler distribution was obtained by employing a novel image analysis. While solvent-free mixing led to a heterogeneous distribution of constituents resulting in limited mechanical property values, a strong improvement of material homogeneity and properties was obtained by using solvent-assisted methods. The results demonstrate the importance of the processing route on final characteristics of polymer-derived ceramics.

  2. A hybrid twin screw extrusion/electrospinning method to process nanoparticle-incorporated electrospun nanofibres

    International Nuclear Information System (INIS)

    Erisken, Cevat; Kalyon, Dilhan M; Wang Hongjun

    2008-01-01

    A new hybrid methodology that fully integrates the processing capabilities of the twin screw extrusion process (conveying solids, melting, dispersive and distributive mixing, pressurization, temperature profiling, devolatilization) with electrospinning is described. The hybrid process is especially suited to the dispersion of nanoparticles into polymeric binders and the generation of nanoparticle-incorporated fibres and nanofibres. The new technology base is demonstrated with the dispersion of β-tricalcium phosphate (β-TCP) nanoparticles into poly(ε-caprolactone) (PCL) to generate biodegradable non-woven meshes that can be targeted as scaffolds for tissue engineering applications. The new hybrid method yielded fibre diameters in the range of 200-2000 nm for both PCL and β-TCP/PCL (35% by weight) composite scaffolds. The degree of crystallinity of polycaprolactone meshes could be manipulated in the 35.1-41% range, using the voltage strength as a parameter. The electrospinning process, integrated with dispersive kneading disc elements, facilitated the decrease of the cluster sizes and allowed the continuous compounding of the nanoparticles into the biodegradable polymer prior to electrospinning. Thermogravimetric analysis (TGA) of the non-woven meshes validated the continuous incorporation of 35 ± 1.5% (by weight) β-TCP nanoparticles for a targeted concentration of 35%. Uniaxial tensile testing of the meshes with and without the nanoparticles indicated that the ultimate tensile strength at break of the meshes increased from 0.47 ± 0.04 to 0.79 ± 0.08 MPa upon the incorporation of the β-TCP nanoparticles. This demonstration study suggests that the new technology base is particularly suitable for the concomitant dispersion and electrospinning of nanoparticles in the generation of myriad types of functional nanofibres

  3. A Method to Incorporate Floor Plan Constraints into Indoor Location Tracking: A Voronoi Approach

    Directory of Open Access Journals (Sweden)

    John D. Hobby

    2018-01-01

    Full Text Available Indoor localization has attracted a lot of research effort in recent years due to the explosion of indoor location-based service (LBS applications. Incorporating map constraints into localization algorithms reduces the uncertainty of walking trajectories and enhances location accuracy. Suitable maps for computer-aided localization algorithms are not readily available, and hence most researchers working on localization solutions manually create maps for their specific localization scenarios. This paper presents a method of generating indoor maps suitable for localization algorithms from CAD floor plans. Our solution is scalable for mass-market LBS deployment. We also propose an adapted map-filtering algorithm that utilizes map information extracted from CAD floor plans. We evaluate the performance of our solution via real-world Wi-Fi RF measurements.

  4. Growth kinetics and morphology of a ballistic deposition model that incorporates surface diffusion for two species

    International Nuclear Information System (INIS)

    El-Nashar, H.F.; Cerdeira, H.A.

    1998-08-01

    We introduce a ballistic deposition model for two kinds of particles (active and inactive) in (2+1) dimensions upon introducing the surface diffusion for the inactive particles. A morphological structural transition is found as the probability of being the inactive particle increases. This transition is well defined by the change in the behavior of the surface width when it is plotted versus time and probability. The exponents α and β calculated for different values of probability show the same behavior. The presence of both types of particles issues three different processes that control the growing surface: overhanging, nonlocal growth and diffusion. It finally leads to a morphological structural transition where the universality changes away from that of Kardar-Parisi-Zhang, in (2+1) dimensions, but not into Edwards-Wilkinson's. (author)

  5. Effect of Nanoparticle Incorporation and Surface Coating on Mechanical Properties of Bone Scaffolds: A Brief Review

    Directory of Open Access Journals (Sweden)

    Jesus Corona-Gomez

    2016-07-01

    Full Text Available Mechanical properties of a scaffold play an important role in its in vivo performance in bone tissue engineering, due to the fact that implanted scaffolds are typically subjected to stress including compression, tension, torsion, and shearing. Unfortunately, not all the materials used to fabricate scaffolds are strong enough to mimic native bones. Extensive research has been conducted in order to increase scaffold strength and mechanical performance by incorporating nanoparticles and/or coatings. An incredible improvement has been achieved; and some outstanding examples are the usage of nanodiamond, hydroxyapatite, bioactive glass particles, SiO2, MgO, and silver nanoparticles. This review paper aims to present the results, to summarize significant findings, and to give perspective for future work, which could be beneficial to future bone tissue engineering.

  6. Effect of Nanoparticle Incorporation and Surface Coating on Mechanical Properties of Bone Scaffolds: A Brief Review

    Science.gov (United States)

    Corona-Gomez, Jesus; Chen, Xiongbiao; Yang, Qiaoqin

    2016-01-01

    Mechanical properties of a scaffold play an important role in its in vivo performance in bone tissue engineering, due to the fact that implanted scaffolds are typically subjected to stress including compression, tension, torsion, and shearing. Unfortunately, not all the materials used to fabricate scaffolds are strong enough to mimic native bones. Extensive research has been conducted in order to increase scaffold strength and mechanical performance by incorporating nanoparticles and/or coatings. An incredible improvement has been achieved; and some outstanding examples are the usage of nanodiamond, hydroxyapatite, bioactive glass particles, SiO2, MgO, and silver nanoparticles. This review paper aims to present the results, to summarize significant findings, and to give perspective for future work, which could be beneficial to future bone tissue engineering. PMID:27420104

  7. In vitro study on the osteogenesis enhancement effect of BMP-2 incorporated biomimetic apatite coating on titanium surfaces.

    Science.gov (United States)

    Zhu, Xiaojing; Zhang, Hui; Zhang, Xinchun; Ning, Chengyun; Wang, Yan

    2017-09-26

    To fabricate a sustained-release delivery system of bone morphogenetic protein (BMP-2) on titanium surface, explore the effect of BMP-2 concentration on the loading/release behavior of BMP-2 and evaluate the cell compatibility of the system in vitro, pure titanium specimens were immersed into supersaturated calcium phosphate solutions (SCP) containing 4 different concentrations of BMP-2: 0, 50, 100, 200 and 400 ng/mL. Biomimetic calcium phosphate coating was formed on titanium surface and BMP-2 was incorporated into the coating through co-deposition. The release profile of BMP-2 suggested that BMP-2 were delivered sustainably up to 20 days. CCK-8 and ALP assay showed that 200 group and 400 ng/mL BMP-2 group have significant effect on promoting MC3T3-E1 cell proliferation and differentiation. The BMP-2 incorporated into the hybrid coating released in a sustained manner and significantly promoted the proliferation and differentiation of MC3T3-E1 on the titanium surface.

  8. Method for surface treatment by electron beams

    International Nuclear Information System (INIS)

    Panzer, S.; Doehler, H.; Bartel, R.; Ardenne, T. von.

    1985-01-01

    The invention has been aimed at simplifying the technology and saving energy in modifying surfaces with the aid of electron beams. The described beam-object geometry allows to abandon additional heat treatments. It can be used for surface hardening

  9. Effects of calcium ion incorporation on osteoblast gene expression in MC3T3-E1 cells cultured on microstructured titanium surfaces.

    Science.gov (United States)

    Park, Jin-Woo; Suh, Jo-Young; Chung, Hyun-Ju

    2008-07-01

    The surface characteristics of a calcium ion (Ca)-incorporated titanium (Ti) surface, produced by hydrothermal treatment using an alkaline Ca-containing solution, and its effects on osteoblastic differentiation were investigated. MC3T3-E1 pre-osteoblastic cells were cultured on machined or grit-blasted Ti surfaces with and without Ca incorporation. The MTT assay was used to determine cell proliferation, and real-time PCR was used for quantitative analysis of osteoblastic gene expression. Hydrothermal treatment with a Ca-containing solution produced a crystalline CaTiO(3) nanostructure of approximately 100 nm in dimension, preserving original micron-scaled surface topographies and microroughness caused by machining, blasting, or blasting and etching treatments. After immersion in Hank's balanced salt solution, considerable apatite formation was observed on all surfaces of the Ca-incorporated samples. Significantly more cell proliferation was found on Ca-incorporated Ti surfaces than on untreated Ti surfaces (p < 0.001). Quantitative real-time PCR analysis showed notably higher alkaline phosphatase, osteopontin, and osteocalcin mRNA levels in cells grown on Ca-incorporated blasted surfaces than on other surfaces at an early time point. Thus, Ca incorporation may have a beneficial effect on osseointegration of microstructured Ti implants by accelerating osteoblast proliferation and differentiation during the early healing phase following implantation. (c) 2007 Wiley Periodicals, Inc.

  10. RBS, PIXE and NDP study of erbium incorporation into glass surface for photonics applications

    Czech Academy of Sciences Publication Activity Database

    Macková, Anna; Havránek, Vladimír; Vacík, Jiří; Salavcová, Linda; Spirková-Hradilová, J.

    2006-01-01

    Roč. 249, 1-2 (2006), s. 856-858 ISSN 0168-583X R&D Projects: GA AV ČR(CZ) KJB100480601; GA ČR GA106/03/0505; GA ČR GA106/05/0706 Institutional research plan: CEZ:AV0Z10480505; CEZ:AV0Z20670512 Keywords : surface analyses * photonics glass * Er diffusion Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.946, year: 2006

  11. Incorporating and Compensating Cerebrospinal Fluid in Surface-Based Forward Models of Magneto- and Electroencephalography.

    Directory of Open Access Journals (Sweden)

    Matti Stenroos

    Full Text Available MEG/EEG source imaging is usually done using a three-shell (3-S or a simpler head model. Such models omit cerebrospinal fluid (CSF that strongly affects the volume currents. We present a four-compartment (4-C boundary-element (BEM model that incorporates the CSF and is computationally efficient and straightforward to build using freely available software. We propose a way for compensating the omission of CSF by decreasing the skull conductivity of the 3-S model, and study the robustness of the 4-C and 3-S models to errors in skull conductivity. We generated dense boundary meshes using MRI datasets and automated SimNIBS pipeline. Then, we built a dense 4-C reference model using Galerkin BEM, and 4-C and 3-S test models using coarser meshes and both Galerkin and collocation BEMs. We compared field topographies of cortical sources, applying various skull conductivities and fitting conductivities that minimized the relative error in 4-C and 3-S models. When the CSF was left out from the EEG model, our compensated, unbiased approach improved the accuracy of the 3-S model considerably compared to the conventional approach, where CSF is neglected without any compensation (mean relative error 40%. The error due to the omission of CSF was of the same order in MEG and compensated EEG. EEG has, however, large overall error due to uncertain skull conductivity. Our results show that a realistic 4-C MEG/EEG model can be implemented using standard tools and basic BEM, without excessive workload or computational burden. If the CSF is omitted, compensated skull conductivity should be used in EEG.

  12. Improvement of surface wetting properties of poly(p-phenylene benzoxazole) by incorporation of ionic groups

    Energy Technology Data Exchange (ETDEWEB)

    Luo Kaiqing [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 200051 (China); Jin Junhong [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 200051 (China); Yang Shenglin [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 200051 (China); Li Guang [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 200051 (China)]. E-mail: lig@dhu.edu.cn; Jiang Jianming [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 200051 (China)

    2006-07-25

    Modified poly(p-phenylene benzoxazole), SPBO, containing ionic sulfonate groups was synthesized by polycondensation of the corresponding monomers in polyphosphoric acid. SPBO fiber was spun via a dry-jet wet-spinning technique. The wetting property of poly(p-phenylene benzoxazole) (PBO) fiber and SPBO fiber were measured by contact angle analysis, and the interfacial shear strength (IFSS) between fibers and epoxy was determined by microbond pull-out testing. The contact angles of water and ethanol on SPBO fiber surface get smaller, and the wetting process becomes faster. The surface free energy of SPBO fiber increases to 38.9 mJ m{sup -2}, which is 9.6% higher than that of PBO fiber. Furthermore the ionic introducing leads to a 23% increase in IFSS from 8.2 MPa for PBO/epoxy to 10.1 MPa for SPBO/epoxy. It could be expected that the failure mode may change from fiber/matrix interface adhesive failure to partly cohesive failure mode.

  13. Durable Self-Cleaning Coatings for Architectural Surfaces by Incorporation of TiO₂ Nano-Particles into Hydroxyapatite Films.

    Science.gov (United States)

    Sassoni, Enrico; D'Amen, Eros; Roveri, Norberto; Scherer, George W; Franzoni, Elisa

    2018-01-23

    To prevent soiling of marble exposed outdoors, the use of TiO₂ nano-particles has been proposed in the literature by two main routes, both raising durability issues: (i) direct application to marble surface, with the risk of particle leaching by rainfall; (ii) particle incorporation into inorganic or organic coatings, with the risk of organic coating degradation catalyzed by TiO₂ photoactivity. Here, we investigated the combination of nano-TiO₂ and hydroxyapatite (HAP), previously developed for marble protection against dissolution in rain and mechanical consolidation. HAP-TiO₂ combination was investigated by two routes: (i) sequential application of HAP followed by nano-TiO₂ ("H+T"); (ii) simultaneous application by introducing nano-TiO₂ into the phosphate solution used to form HAP ("HT"). The self-cleaning ability was evaluated before and after prolonged exposure to simulated rain. "H+T" and "HT" coatings exhibited much better resistance to nano-TiO₂ leaching by rain, compared to TiO₂ alone. In "H+T" samples, TiO₂ nano-particles adhere better to HAP (having flower-like morphology and high specific surface area) than to marble. In "HT" samples, thanks to chemical bonds between nano-TiO₂ and HAP, the particles are firmly incorporated in the HAP coating, which protects them from leaching by rain, without diminishing their photoactivity and without being degraded by them.

  14. X-ray detection capabilities of plastic scintillators incorporated with hafnium oxide nanoparticles surface-modified with phenyl propionic acid

    Science.gov (United States)

    Hiyama, Fumiyuki; Noguchi, Takio; Koshimizu, Masanori; Kishimoto, Shunji; Haruki, Rie; Nishikido, Fumihiko; Yanagida, Takayuki; Fujimoto, Yutaka; Aida, Tsutomu; Takami, Seiichi; Adschiri, Tadafumi; Asai, Keisuke

    2018-01-01

    We synthesized plastic scintillators incorporated with HfO2 nanoparticles as detectors for X-ray synchrotron radiation. Nanoparticles with sizes of less than 10 nm were synthesized with the subcritical hydrothermal method. The detection efficiency of high-energy X-ray photons improved by up to 3.3 times because of the addition of the nanoparticles. Nanosecond time resolution was successfully achieved for all the scintillators. These results indicate that this method is applicable for the preparation of plastic scintillators to detect X-ray synchrotron radiation.

  15. Optimization of VCSELs incorporating monolithic subwavelength high-refractive-index contrast surface grating mirrors

    Science.gov (United States)

    Gebski, Marcin; Marciniak, Magdalena; Dems, Maciej; Czyszanowski, Tomasz; Lott, James A.

    2017-02-01

    We present results of computer simulations of vertical cavity surface emitting lasers (VCSELs) using novel, highreflectivity monolithic high refractive-index contrast grating (MHCG) mirrors and their more advanced version, partially covered by a thin metal layer - metallic MHCG (mMHCG) mirrors. The first experimental realization of this new class of mirrors is presented and discussed. We show that the metal layer does not deteriorate the high reflectivity of an mMHCG mirror, but in contrary, is a crucial element which allows high reflectivity and additionally opens a way for a more efficient electrical pumping of a VCSEL. Comparison of results of thermal-electrical-carrier-gain self-consistent simulations of both MHCG- and mMHCG-based VCSELs is presented and discussed. It is shown that using mHCG mirror as a top mirror of a VCSEL improves electrical characteristics and greatly decreases the differential resistance of the device.

  16. Global Cr-isotope distributions in surface seawater and incorporation of Cr isotopes into carbonate shells

    DEFF Research Database (Denmark)

    Paulukat, Cora Stefanie; Frei, Robert; Vögelin, Andrea Regula

    In this study we present the Cr-isotope composition of surface seawater from several locations worldwide. In addition to the samples from the oceans (Atlantic Ocean, Pacific Ocean, Southern Ocean and Artic Ocean) we analysed water samples from areas with a more limited water exchange (Mediterranean...... Sea, Baltic Sea, Øresund and Kattegat). The long residence time of Cr (7,000 to 40,000 years) [1,2,3] relative to the ocean mixing time (1,000 to 2,000 years) [4] could lead to the expectation that the Cr concentration and Cr-isotope distribution are homogeneous in the oceans. However, our seawater...... observed a negative correlation between the Cr-isotope composition and the Cr concentration. Exceptions are samples from the Baltic Sea/Øresund, which are isotopically light despite low Cr concentrations (~0.1-0.2 ppb). In addition to the seawater data, we measured Cr isotopes in modern biologically...

  17. Characterize Cold Bituminous Emulsion Mixtures Incorporated Ordinary Portland Cement Filler for Local Surface Layer

    Directory of Open Access Journals (Sweden)

    Mustafa Amoori Kadhim

    2018-02-01

    Full Text Available Cold Bituminous Emulsion Mixtures have many environmental, logistical, and economic advantages over conventional Hot Mix Asphalt. Nevertheless, their inferior performance and high water sensitivity at early life attract little attentions. Moreover, it is impossible to apply CBEM as a structural surface layer if left without treatment or enhancement. The main aim of this study is to enhance the properties of CBEM for the hope of using it as a structural layer. Thus, a trial has been made to improve CBEM mechanical and durability properties by replacing the Ordinary Portland Cement by the Conventional Mineral Filler with 3 percentages; namely, 0, 50%, and 100%. CBEM mixtures mechanical properties were evaluated in term of Marshall Stability and Flow, Indirect Tensile Strength, and Wheel Track Test. While Moisture damage was evaluated in terms of Retained Marshall Stability. Test results showed that the addition of 100%OPC filler can improve CBEM mechanical and durability properties efficiently. In terms of mechanical properties results, CBEM comprised 100%OPC, can be used as a structural Surface layer based on local Iraqi specifications limits, where mixture enhanced about 1.9, 1.78, 9,4.85, and 2.6  times in term of MS, MF, rutting deformation resistance, resistance to tensile cracking, and moisture damage resistance, respectively as compared to untreated CBEM. Also, CBEM-100%OPC mix seemed comparable (and sometime superior to HMA, e.g., resistance to rutting of CBEM is about 6.2 times higher than that of HMA. It’s worth to say that OPC upgrades CBEM to a significant level that enables it to use as a structural layer in terms of the mechanical and the durability properties.

  18. Surface Imaging Skin Friction Instrument and Method

    Science.gov (United States)

    Brown, James L. (Inventor); Naughton, Jonathan W. (Inventor)

    1999-01-01

    A surface imaging skin friction instrument allowing 2D resolution of spatial image by a 2D Hilbert transform and 2D inverse thin-oil film solver, providing an innovation over prior art single point approaches. Incoherent, monochromatic light source can be used. The invention provides accurate, easy to use, economical measurement of larger regions of surface shear stress in a single test.

  19. A method of determining surface runoff by

    Science.gov (United States)

    Donald E. Whelan; Lemuel E. Miller; John B. Cavallero

    1952-01-01

    To determine the effects of watershed management on flood runoff, one must make a reliable estimate of how much the surface runoff can be reduced by a land-use program. Since surface runoff is the difference between precipitation and the amount of water that soaks into the soil, such an estimate must be based on the infiltration capacity of the soil.

  20. System and method for free-boundary surface extraction

    KAUST Repository

    Algarni, Marei

    2017-10-26

    A method of extracting surfaces in three-dimensional data includes receiving as inputs three-dimensional data and a seed point p located on a surface to be extracted. The method further includes propagating a front outwardly from the seed point p and extracting a plurality of ridge curves based on the propagated front. A surface boundary is detected based on a comparison of distances between adjacent ridge curves and the desired surface is extracted based on the detected surface boundary.

  1. Incorporating operational flexibility into electric generation planning Impacts and methods for system design and policy analysis

    Science.gov (United States)

    Palmintier, Bryan S.

    impacts occur; 2. Demonstrating that a failure to account for operational flexibility can result in undesirable outcomes for both utility planners and policy analysts; and 3. Extending the state of the art for electric power system models by introducing a tractable method for incorporating unit commitment based operational flexibility at full 876o hourly resolution directly into planning optimization. Together these results encourage and offer a new flexibility-aware approach for capacity planning and accompanying policy design that can enable cleaner, less expensive electric power systems for the future. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs mit.edu)

  2. Nonpolar III-nitride vertical-cavity surface-emitting lasers incorporating an ion implanted aperture

    KAUST Repository

    Leonard, J. T.

    2015-07-06

    © 2015 AIP Publishing LLC. We report on our recent progress in improving the performance of nonpolar III-nitride vertical-cavity surface-emitting lasers (VCSELs) by using an Al ion implanted aperture and employing a multi-layer electron-beam evaporated ITO intracavity contact. The use of an ion implanted aperture improves the lateral confinement over SiNx apertures by enabling a planar ITO design, while the multi-layer ITO contact minimizes scattering losses due to its epitaxially smooth morphology. The reported VCSEL has 10 QWs, with a 3nm quantum well width, 1nm barriers, a 5nm electron-blocking layer, and a 6.95- λ total cavity thickness. These advances yield a single longitudinal mode 406nm nonpolar VCSEL with a low threshold current density (∼16kA/cm2), a peak output power of ∼12μW, and a 100% polarization ratio. The lasing in the current aperture is observed to be spatially non-uniform, which is likely a result of filamentation caused by non-uniform current spreading, lateral optical confinement, contact resistance, and absorption loss.

  3. A volume-based method for denoising on curved surfaces

    KAUST Repository

    Biddle, Harry

    2013-09-01

    We demonstrate a method for removing noise from images or other data on curved surfaces. Our approach relies on in-surface diffusion: we formulate both the Gaussian diffusion and Perona-Malik edge-preserving diffusion equations in a surface-intrinsic way. Using the Closest Point Method, a recent technique for solving partial differential equations (PDEs) on general surfaces, we obtain a very simple algorithm where we merely alternate a time step of the usual Gaussian diffusion (and similarly Perona-Malik) in a small 3D volume containing the surface with an interpolation step. The method uses a closest point function to represent the underlying surface and can treat very general surfaces. Experimental results include image filtering on smooth surfaces, open surfaces, and general triangulated surfaces. © 2013 IEEE.

  4. Oxygen isotope evidence for sorption of molecular oxygen to pyrite surface sites and incorporation into sulfate in oxidation experiments

    International Nuclear Information System (INIS)

    Tichomirowa, Marion; Junghans, Manuela

    2009-01-01

    Experiments were conducted to investigate (i) the rate of O-isotope exchange between SO 4 and water molecules at low pH and surface temperatures typical for conditions of acid mine drainage (AMD) and (ii) the O- and S-isotope composition of sulfates produced by pyrite oxidation under closed and open conditions (limited and free access of atmospheric O 2 ) to identify the O source/s in sulfide oxidation (water or atmospheric molecular O 2 ) and to better understand the pyrite oxidation pathway. An O-isotope exchange between SO 4 and water was observed over a pH range of 0-2 only at 50 deg. C, whereas no exchange occurred at lower temperatures over a period of 8 a. The calculated half-time of the exchange rate for 50 deg. C (pH = 0 and 1) is in good agreement with former experimental data for higher and lower temperatures and excludes the possibility of isotope exchange for typical AMD conditions (T ≤ 25 deg. C, pH ≥ 3) for decades. Pyrite oxidation experiments revealed two dependencies of the O-isotope composition of dissolved sulfates: O-isotope values decreased with longer duration of experiments and increasing grain size of pyrite. Both changes are interpreted as evidence for chemisorption of molecular O 2 to pyrite surface sites. The sorption of molecular O 2 is important at initial oxidation stages and more abundant in finer grained pyrite fractions and leads to its incorporation in the produced SO 4 . The calculated bulk contribution of atmospheric O 2 in the dissolved SO 4 reached up to 50% during initial oxidation stages (first 5 days, pH 2, fine-grained pyrite fraction) and decreased to less than 20% after about 100 days. Based on the direct incorporation of molecular O 2 in the early-formed sulfates, chemisorption and electron transfer of molecular O 2 on S sites of the pyrite surface are proposed, in addition to chemisorption on Fe sites. After about 10 days, the O of all newly-formed sulfates originates only from water, indicating direct interaction

  5. Surface analysis methods in materials science

    CERN Document Server

    Sexton, Brett; Smart, Roger

    1992-01-01

    The idea for this book stemmed from a remark by Philip Jennings of Murdoch University in a discussion session following a regular meeting of the Australian Surface Science group. He observed that a text on surface analysis and applica­ tions to materials suitable for final year undergraduate and postgraduate science students was not currently available. Furthermore, the members of the Australian Surface Science group had the research experience and range of coverage of sur­ face analytical techniques and applications to provide a text for this purpose. A of techniques and applications to be included was agreed at that meeting. The list intended readership of the book has been broadened since the early discussions, particularly to encompass industrial users, but there has been no significant alter­ ation in content. The editors, in consultation with the contributors, have agreed that the book should be prepared for four major groups of readers: - senior undergraduate students in chemistry, physics, metallur...

  6. Incorporating an Inert Polymer into the Interlayer Passivates Surface Defects in Methylammonium Lead Halide Perovskite Solar Cells.

    Science.gov (United States)

    Bi, Shiqing; Zhang, Xuning; Qin, Liang; Wang, Rong; Zhou, Jiyu; Leng, Xuanye; Qiu, Xiaohui; Zhang, Yuan; Zhou, Huiqiong; Tang, Zhiyong

    2017-10-17

    The hysteresis effect and instability are important concerns in hybrid perovskite photovoltaic devices that hold great promise in energy conversion applications. In this study, we show that the power conversion efficiency (PCE), hysteresis, and device lifetime can be simultaneously improved for methylammoniumlead halide (CH 3 NH 3 PbI 3-x Cl x ) solar cells after incorporating poly(methyl methacrylate) (PMMA) into the PC 61 BM electron extraction layer (EEL). By choosing appropriate molecular weights of PMMA, we obtain a 30 % enhancement of PCE along with effectively lowered hysteresis and device degradation, adopting inverted planar device structure. Through the combinatorial study using Kelvin probe force microscopy, diode mobility measurements, and irradiation-dependent solar cell characterization, we attribute the enhanced device parameters (fill factor and open circuit voltage) to the surface passivation of CH 3 NH 3 PbI 3-x Cl x , leading to mitigating charge trapping at the cathode interface and resultant Shockley-Read-Hall charge recombination. Beneficially, modified by inert PMMA, CH 3 NH 3 PbI 3-x Cl x solar cells display a pronounced retardation in performance degradation, resulting from improved film quality in the PC 61 BM layer incorporating PMMA which increases the protection for underneath perovskite films. This work enables a versatile and effective interface approach to deal with essential concerns for solution-processed perovskite solar cells by air-stable and widely accessible materials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Surface control alloy substrates and methods of manufacture therefor

    Energy Technology Data Exchange (ETDEWEB)

    Fritzemeier, Leslie G. (Mendon, MA); Li, Qi (Marlborough, MA); Rupich, Martin W. (Framingham, MA); Thompson, Elliott D. (Coventry, RI); Siegal, Edward J. (Malden, MA); Thieme, Cornelis Leo Hans (Westborough, MA); Annavarapu, Suresh (Brookline, MA); Arendt, Paul N. (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM)

    2004-05-04

    Methods and articles for controlling the surface of an alloy substrate for deposition of an epitaxial layer. The invention includes the use of an intermediate layer to stabilize the substrate surface against oxidation for subsequent deposition of an epitaxial layer.

  8. Incorporating the Uncertainties of Nodal-Plane Orientation in the Seismo-Lineament Analysis Method (SLAM)

    Science.gov (United States)

    Cronin, V.; Sverdrup, K. A.

    2013-05-01

    The process of delineating a seismo-lineament has evolved since the first description of the Seismo-Lineament Analysis Method (SLAM) by Cronin et al. (2008, Env & Eng Geol 14(3) 199-219). SLAM is a reconnaissance tool to find the trace of the fault that produced an shallow-focus earthquake by projecting the corresponding nodal planes (NP) upward to their intersections with the ground surface, as represented by a DEM or topographic map. A seismo-lineament is formed by the intersection of the uncertainty volume associated with a given NP and the ground surface. The ground-surface trace of the fault that produced the earthquake is likely to be within one of the two seismo-lineaments associated with the two NPs derived from the earthquake's focal mechanism solution. When no uncertainty estimate has been reported for the NP orientation, the uncertainty volume associated with a given NP is bounded by parallel planes that are [1] tangent to the ellipsoidal uncertainty volume around the focus and [2] parallel to the NP. If the ground surface is planar, the resulting seismo-lineament is bounded by parallel lines. When an uncertainty is reported for the NP orientation, the seismo-lineament resembles a bow tie, with the epicenter located adjacent to or within the "knot." Some published lists of focal mechanisms include only one NP with associated uncertainties. The NP orientation uncertainties in strike azimuth (+/- gamma), dip angle (+/- epsilon) and rake that are output from an FPFIT analysis (Reasenberg and Oppenheimer, 1985, USGS OFR 85-739) are taken to be the same for both NPs (Oppenheimer, 2013, pers com). The boundaries of the NP uncertainty volume are each comprised by planes that are tangent to the focal uncertainty ellipsoid. One boundary, whose nearest horizontal distance from the epicenter is greater than or equal to that of the other boundary, is formed by the set of all planes with strike azimuths equal to the reported NP strike azimuth +/- gamma, and dip angle

  9. Fabrication of polyester microchannel with functional surface for electro-chromatography - Incorporation of detection devices into the microchip -

    International Nuclear Information System (INIS)

    Uchiyama, Katsumi; Qiu, Jing Miao; Hobo, Toshiyuki

    2001-01-01

    In recent years, new analytical techniques using microchip devise have been extensively studied (micro-TAS). One of the most successful examples is capillary electrophoresis (CE) with glass plate fabricated by photolithography followed by the chemical or physical etching process. Micro CE one of the most excellent separation techniques, performs separations in microchannel formed in appreciate substrate material. We developed a fabrication method for polyester micro channels with aikene alcohol inside the wall of the channel and demonstrated the usefulness of the polymer microchip. Although many researchers have been studying microchannel or micro-devices for analytical use, miniaturization of the total system including sample introduction, separation, detection and data treatment is still under development. Especially, the miniaturization of the detection system will be a hard bar to be overcome. Our method, based upon the in situ polymerization of polyester resin on an appreciate template, can be exported to let some parts incorporated directly into the microchip during the polymerization process. In this paper, we will describe the incorporation of detection components (light emitting diode and optical fiber) into polyester microchip and the application of the microchip to the analysis of amino acids separated by electrophoresis.

  10. Trainable Methods for Surface Natural Language Generation

    OpenAIRE

    Ratnaparkhi, Adwait

    2000-01-01

    We present three systems for surface natural language generation that are trainable from annotated corpora. The first two systems, called NLG1 and NLG2, require a corpus marked only with domain-specific semantic attributes, while the last system, called NLG3, requires a corpus marked with both semantic attributes and syntactic dependency information. All systems attempt to produce a grammatical natural language phrase from a domain-specific semantic representation. NLG1 serves a baseline syst...

  11. Electrical and Optical Properties of Si-Incorporated a-C:H Films via the Radio Frequency Plasma-Enhanced Chemical Vapor Deposition Method.

    Science.gov (United States)

    Kim, In Jun; Choi, Won Seok; Hong, Byungyou

    2016-05-01

    The optical and electrical properties of silicon-incorporated hydrogenated amorphous carbon (a-C:H:Si) films deposited via the radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) method using a mixture of CH4, H2, and SiH4 were observed. The silane gas whose ranged from 0 to 25 vol.% [SiH4/(SiH4 + CH4) was fed into the reactor while the other deposition parameters were kept constant. The basic properties of these films were investigated via Raman spectroscopy, UV-visible spectrometry, I-V measurement, and surface profiling. The experiment results showed that the film thickness increased from 300 nm to 800 nm for the same deposition time as the silane gas increased. The Raman spectrum obtained from the silicon-incorporated a-C:H films suggested that the film property changed from graphitic-like to more diamond-like. As the silane gas increased, the optical gap, E04, slightly increased from 1.98 eV to 2.62 eV. It was shown that the Si atoms incorporated into the a-C:H films reduced the size of the sp2 clusters. As for the I-V characteristics, the Si-incorporated a-C:H films had a lower leakage current than the a-C:H films without Si.

  12. Surface renewal method for estimating sensible heat flux | Mengistu ...

    African Journals Online (AJOL)

    For short canopies, latent energy flux may be estimated using a shortened surface energy balance from measurements of sensible and soil heat flux and the net irradiance at the surface. The surface renewal (SR) method for estimating sensible heat, latent energy, and other scalar fluxes has the advantage over other ...

  13. Method for treatment of a surface area of steel

    NARCIS (Netherlands)

    Bhowmik, S.; Aaldert, P.J.

    2009-01-01

    The invention relates to a method for treatment of a surface area of steel by polishing said surface area and performing a plasma treatment of said surface area wherein the plasma treatment is performed at at least atmospheric conditions and wherein the plasma treatment is carried out at a power of

  14. In vitro method determing sensitivity of anticancer agents by incorporation of radioactive precursors

    International Nuclear Information System (INIS)

    Sakakibara, Satoshi

    1983-01-01

    A new sensitivity test of anticancer agents was developed to measure the lethal effects of cancer cells by the incorporation of radioactive precursors. The thousand cancer cells were cultured in a microplate in the presence of anticancer agents. These cells were exposed to radioactive precursors. Two or three days later, the cancer cells were harvested on a glass fiver filter by a multiple automatic cell-harvester and the incorporation of precursors was counted by a liquid scintillation counter. In this study, the in vivo results of drug testing in animal model systems were compared with drug sensitivities. Mice inoculated Ehrlich ascites cells were treated with various kinds of anticancer drugs. The development of the cells was compatible with the result of the sensitivity test. The growths of Lauson and ME-180 cells derived from human cancers implanted subcutaneously to nude mice were also well correlated with this sensitivity test. (author)

  15. Understanding the stability of Fe incorporation within Mn3N2(0 0 1) surfaces: An ab-initio study

    International Nuclear Information System (INIS)

    Guerrero-Sánchez, J.; Mandru, Andrada-Oana; Takeuchi, Noboru; Cocoletzi, Gregorio H.; Smith, Arthur R.

    2016-01-01

    Graphical abstract: - Highlights: • The Fe incorporation into inner layers of the Mn 3 N 2 surfaces is stable in all range of chemical potential. • Displaced Mn atoms forming cluster-like structures induce the stability of incorporated Fe atoms. • Antiferromagnetic alignment in the [0 0 1] direction and in-plane Ferromagnetic Fe–Fe and Fe–Mn alignments are the same as in Mn 3 N 2 bulk structure. • Incorporated Fe layers contribute to the metallic character of these surfaces. - Abstract: We present first principles spin-polarized calculations of the adsorption and incorporation of iron in the Mn 3 N 2 (0 0 1) surfaces. By means of a surface formation energy criterion, it is demonstrated that Fe incorporation is energetically stable for all studied surfaces. An Fe bilayer formation is achieved after Fe atoms displace Mn atoms in the sub-surface N-vacancy layers. An analysis of the magnetic coupling shows an antiferromagnetic alignment along the [0 0 1] direction as in the clean, ideal surfaces. Also, the in-plane magnetic coupling between Fe–Fe and Fe–Mn shows a ferromagnetic tendency, similar to the clean, ideally terminated surfaces. These results clearly indicate that Fe behaves like Mn when adsorbed into the Mn 3 N 2 surface. Density of states calculations of the stable structures show a slight deviation from the antiferromagnetic-like behavior, with the most important contribution around the Fermi level coming from the Fe-d and Mn-d orbitals.

  16. Understanding the stability of Fe incorporation within Mn{sub 3}N{sub 2}(0 0 1) surfaces: An ab-initio study

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Sánchez, J., E-mail: guerrero@ifuap.buap.mx [Department of Physics and Astronomy, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701 (United States); Benemérita Universidad Autónoma de Puebla, Instituto de Física “Ing Luis Rivera Terrazas”, Apartado Postal J-48, Puebla 72570, México (Mexico); Centro de Nanociencias y Nanotecnologia, Universidad Nacional Autónoma de México, Apartado Postal 14, Ensenada, Baja California Codigo Postal 22800, México (Mexico); Mandru, Andrada-Oana [Department of Physics and Astronomy, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701 (United States); Takeuchi, Noboru [Department of Physics and Astronomy, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701 (United States); Centro de Nanociencias y Nanotecnologia, Universidad Nacional Autónoma de México, Apartado Postal 14, Ensenada, Baja California Codigo Postal 22800, México (Mexico); Cocoletzi, Gregorio H. [Benemérita Universidad Autónoma de Puebla, Instituto de Física “Ing Luis Rivera Terrazas”, Apartado Postal J-48, Puebla 72570, México (Mexico); Smith, Arthur R. [Department of Physics and Astronomy, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701 (United States)

    2016-02-15

    Graphical abstract: - Highlights: • The Fe incorporation into inner layers of the Mn{sub 3}N{sub 2} surfaces is stable in all range of chemical potential. • Displaced Mn atoms forming cluster-like structures induce the stability of incorporated Fe atoms. • Antiferromagnetic alignment in the [0 0 1] direction and in-plane Ferromagnetic Fe–Fe and Fe–Mn alignments are the same as in Mn{sub 3}N{sub 2} bulk structure. • Incorporated Fe layers contribute to the metallic character of these surfaces. - Abstract: We present first principles spin-polarized calculations of the adsorption and incorporation of iron in the Mn{sub 3}N{sub 2}(0 0 1) surfaces. By means of a surface formation energy criterion, it is demonstrated that Fe incorporation is energetically stable for all studied surfaces. An Fe bilayer formation is achieved after Fe atoms displace Mn atoms in the sub-surface N-vacancy layers. An analysis of the magnetic coupling shows an antiferromagnetic alignment along the [0 0 1] direction as in the clean, ideal surfaces. Also, the in-plane magnetic coupling between Fe–Fe and Fe–Mn shows a ferromagnetic tendency, similar to the clean, ideally terminated surfaces. These results clearly indicate that Fe behaves like Mn when adsorbed into the Mn{sub 3}N{sub 2} surface. Density of states calculations of the stable structures show a slight deviation from the antiferromagnetic-like behavior, with the most important contribution around the Fermi level coming from the Fe-d and Mn-d orbitals.

  17. Applying isotope methods in flowing surface waters

    International Nuclear Information System (INIS)

    Mook, W.G.

    1976-01-01

    The most frequent application of natural or environmental isotopes to investigate surface water is as tracer. Especially the natural variations in the 18 O/ 16 O ratio in rainfall are traced in streams and rivers. The isotopes deuterium, 13 C and 14 C enable refined applications such as the investigation of geochemical processes in waters. 18 O analyses are fairly fast (20 samples per day can be carried out) and require little water (1 to 10 ml). Therefore, the natural variations in the 18 O/ 16 O ratio of water are treated. There is a certain connection between the 18 O/ 16 O and D/H ratios in rainfall waters. 18 O analyses are somewhat easier to perform so that this technique is generally preferred. Additional D analyses are of great use in detecting geochemical processes, e.g. evaporation. Although tritium is still an important agent in hydrological studies, the concentration variations in nature are now lower than for 18 O compared to the usual experimental error. Furthermore, they are not so important geochemically. Accurate tritium measurements require relatively much time (1 or 2 analyses per day), are expensive (50 DM to 150 DM) and require more material (10 to 500 ml water), depending on the desired accuracy. The stable and radioactive carbon isotopes are mainly used in special cases to study certain geochemical processes. (orig./HK) [de

  18. Determination of functionalized gold nanoparticles incorporated in hydrophilic and hydrophobic microenvironments by surface modification of quartz crystal microbalance

    International Nuclear Information System (INIS)

    Wu, Tsui-Hsun; Liao, Shu-Chuan; Chen, Ying-Fang; Huang, Yi-You; Wei, Yi-Syuan; Tu, Shu-Ju; Chen, Ko-Shao

    2013-01-01

    In this study, plasma deposition methods were used to immobilize Au electrode of a quartz crystal microbalance (QCM) to create different microenvironments for mass measurement of various modified Au nanoparticles (AuNPs). AuNPs were modified by 11-mercaptoundecanoic acid (MUA) and 1-decanethiol (DCT) for potential applications to drug release, protective coatings, and immunosensors. We aimed to develop a highly sensitive and reliable method to quantify the mass of various modified AuNPs. The surface of AuNPs and Au electrode was coated with polymer films, as determined by Fourier transform infrared spectroscopy and atomic force microscopy. Measurements obtained for various AuNPs and the plasma-treated surface of the Au electrode were compared with those obtained for an untreated Au electrode. According to the resonant frequency shift of QCM, a linear relationship was observed that significantly differed for AuNPs, MUA-AuNPs, and DCT-AuNPs (R 2 range, 0.94–0.965, 0.934–0.972, and 0.874–0.9514, respectively). Compared to inductively coupled plasma and micro-computerized tomography, the QCM method with plasma treatment has advantages of real-time monitoring, greater sensitivity, and lower cost. Our results demonstrate that surface modifications measured by a QCM system for various modified AuNPs were reliable.

  19. Fuzzy surfaces in GIS and geographical analysis theory, analytical methods, algorithms and applications

    CERN Document Server

    Lodwick, Weldon

    2007-01-01

    Surfaces are a central to geographical analysis. Their generation and manipulation are a key component of geographical information systems (GISs). However, geographical surface data is often not precise. When surfaces are used to model geographical entities, the data inherently contains uncertainty in terms of both position and attribute. Fuzzy Surface in GIS and Geographical Analysis sets out a process to identify the uncertainty in geographic entities. It describes how to successfully obtain, model, analyze, and display data, as well as interpret results within the context of GIS. Focusing on uncertainty that arises from transitional boundaries, the book limits its study to three types of uncertainties: intervals, fuzzy sets, and possibility distributions. The book explains that uncertainty in geographical data typically stems from these three and it is only natural to incorporate them into the analysis and display of surface data. The book defines the mathematics associated with each method for analysis,...

  20. Incorporation of velocity-dependent restitution coefficient and particle surface friction into kinetic theory for modeling granular flow cooling.

    Science.gov (United States)

    Duan, Yifei; Feng, Zhi-Gang

    2017-12-01

    Kinetic theory (KT) has been successfully used to model rapid granular flows in which particle interactions are frictionless and near elastic. However, it fails when particle interactions become frictional and inelastic. For example, the KT is not able to accurately predict the free cooling process of a vibrated granular medium that consists of inelastic frictional particles under microgravity. The main reason that the classical KT fails to model these flows is due to its inability to account for the particle surface friction and its inelastic behavior, which are the two most important factors that need be considered in modeling collisional granular flows. In this study, we have modified the KT model that is able to incorporate these two factors. The inelasticity of a particle is considered by establishing a velocity-dependent expression for the restitution coefficient based on many experimental studies found in the literature, and the particle friction effect is included by using a tangential restitution coefficient that is related to the particle friction coefficient. Theoretical predictions of the free cooling process by the classical KT and the improved KT are compared with the experimental results from a study conducted on an airplane undergoing parabolic flights without the influence of gravity [Y. Grasselli, G. Bossis, and G. Goutallier, Europhys. Lett. 86, 60007 (2009)10.1209/0295-5075/86/60007]. Our results show that both the velocity-dependent restitution coefficient and the particle surface friction are important in predicting the free cooling process of granular flows; the modified KT model that integrates these two factors is able to improve the simulation results and leads to better agreement with the experimental results.

  1. Incorporation of velocity-dependent restitution coefficient and particle surface friction into kinetic theory for modeling granular flow cooling

    Science.gov (United States)

    Duan, Yifei; Feng, Zhi-Gang

    2017-12-01

    Kinetic theory (KT) has been successfully used to model rapid granular flows in which particle interactions are frictionless and near elastic. However, it fails when particle interactions become frictional and inelastic. For example, the KT is not able to accurately predict the free cooling process of a vibrated granular medium that consists of inelastic frictional particles under microgravity. The main reason that the classical KT fails to model these flows is due to its inability to account for the particle surface friction and its inelastic behavior, which are the two most important factors that need be considered in modeling collisional granular flows. In this study, we have modified the KT model that is able to incorporate these two factors. The inelasticity of a particle is considered by establishing a velocity-dependent expression for the restitution coefficient based on many experimental studies found in the literature, and the particle friction effect is included by using a tangential restitution coefficient that is related to the particle friction coefficient. Theoretical predictions of the free cooling process by the classical KT and the improved KT are compared with the experimental results from a study conducted on an airplane undergoing parabolic flights without the influence of gravity [Y. Grasselli, G. Bossis, and G. Goutallier, Europhys. Lett. 86, 60007 (2009), 10.1209/0295-5075/86/60007]. Our results show that both the velocity-dependent restitution coefficient and the particle surface friction are important in predicting the free cooling process of granular flows; the modified KT model that integrates these two factors is able to improve the simulation results and leads to better agreement with the experimental results.

  2. Chemical method for producing smooth surfaces on silicon wafers

    Science.gov (United States)

    Yu, Conrad

    2003-01-01

    An improved method for producing optically smooth surfaces in silicon wafers during wet chemical etching involves a pre-treatment rinse of the wafers before etching and a post-etching rinse. The pre-treatment with an organic solvent provides a well-wetted surface that ensures uniform mass transfer during etching, which results in optically smooth surfaces. The post-etching treatment with an acetic acid solution stops the etching instantly, preventing any uneven etching that leads to surface roughness. This method can be used to etch silicon surfaces to a depth of 200 .mu.m or more, while the finished surfaces have a surface roughness of only 15-50 .ANG. (RMS).

  3. An Examination of a Music Appreciation Method Incorporating Tactile Sensations from Artificial Vibrations

    Science.gov (United States)

    Ideguchi, Tsuyoshi; Yoshida, Ryujyu; Ooshima, Keita

    We examined how test subject impressions of music changed when artificial vibrations were incorporated as constituent elements of a musical composition. In this study, test subjects listened to several music samples in which different types of artificial vibration had been incorporated and then subjectively evaluated any resulting changes to their impressions of the music. The following results were obtained: i) Even if rhythm vibration is added to a silent component of a musical composition, it can effectively enhance musical fitness. This could be readily accomplished when actual sounds that had been synchronized with the vibration components were provided beforehand. ii) The music could be listened to more comfortably by adding not only a natural vibration extracted from percussion instruments but also artificial vibration as tactile stimulation according to intentional timing. Furthermore, it was found that the test subjects' impression of the music was affected by a characteristic of the artificial vibration. iii) Adding vibration to high-frequency areas can offer an effective and practical way of enhancing the appeal of a musical composition. iv) The movement sensations of sound and vibration could be experienced when the strength of the sound and vibration are modified in turn. These results suggest that the intentional application of artificial vibration could result in a sensitivity amplification factor on the part of a listener.

  4. ROUGHNESS ON WOOD SURFACES AND ROUGHNESS MEASUREMENT METHODS

    Directory of Open Access Journals (Sweden)

    İsmail Aydın

    2003-04-01

    Full Text Available Some visual characteristics of wood such as color, pattern and texture determine the quality of manufactured products. Surface properties of wood material are important both in production and marketing after production. Initial studies related to the roughness of wood surface were begun in early 1950’s. However, no general agreed standardization can not have been developed for wood surfaces. Surface roughness of wood is function of the production process, product type and the natural anatomical properties of wood. Contact and non-contact tracing methods are used to measure of wood surface roughness. Surface roughness also affects the gluability and wettability of wood surfaces. The success in finishing also depends on the surface roughness of wood.

  5. Formation of Reflecting Surfaces Based on Spline Methods

    Science.gov (United States)

    Zamyatin, A. V.; Zamyatina, E. A.

    2017-11-01

    The article deals with problem of reflecting barriers surfaces generation by spline methods. The cases of reflection when a geometric model is applied are considered. The surfaces of reflecting barriers are formed in such a way that they contain given points and the rays reflected at these points and hit at the defined points of specified surface. The reflecting barrier surface is formed by cubic splines. It enables a comparatively simple implementation of proposed algorithms in the form of software applications. The algorithms developed in the article can be applied in architecture and construction design for reflecting surface generation in optics and acoustics providing the geometrical model of reflex processes is used correctly.

  6. System and method for extracting a sample from a surface

    Science.gov (United States)

    Van Berkel, Gary; Covey, Thomas

    2015-06-23

    A system and method is disclosed for extracting a sample from a sample surface. A sample is provided and a sample surface receives the sample which is deposited on the sample surface. A hydrophobic material is applied to the sample surface, and one or more devices are configured to dispense a liquid on the sample, the liquid dissolving the sample to form a dissolved sample material, and the one or more devices are configured to extract the dissolved sample material from the sample surface.

  7. Safety and effectiveness of early loaded maxillary titanium implants with a novel nanostructured calcium-incorporated surface (Xpeed): 3-year results from a pilot multicenter randomised controlled trial.

    Science.gov (United States)

    Felice, Pietro; Grusovin, Maria Gabriella; Barausse, Carlo; Grandi, Giovanni; Esposito, Marco

    2015-01-01

    To evaluate clinical safety and effectiveness of a novel calcium-incorporated titanium implant surface (Xpeed, MegaGen Implant Co., Gyeongbuk, South Korea). Sixty patients were randomised to receive one to six implants in the maxilla with either calcium-incorporated (Xpeed) or control resorbable blasted media (RBM) surfaces, according to a parallel group design at two centres. Implants were submerged and exposed at three different endpoints in equal groups of 20 patients, each at 12, 10 and 8 weeks, respectively. Within 2 weeks, implants were functionally loaded with provisional or definitive prostheses. Outcome measures were prosthesis failures, implant failures, any complications and peri-implant marginal bone level changes. Thirty patients received 45 calcium-incorporated implants and 30 patients received 42 control titanium implants. Three years after loading four patients dropped-out from the Xpeed group and one from the RBM group. No prosthesis or implant failures occurred. There were no statistically significant differences between the groups for complications (P = 0.91; difference in proportions = 0.79 %; 95% CI -0.71 to 2.29) and mean marginal bone level changes (P = 0.88; mean difference = -0.02 mm; 95% CI -0.26 to 0.22). Both implant surfaces provided good clinical results and no significant difference was found when comparing titanium implants with a nanostructured calcium-incorporated surface versus implants with RBM surfaces.

  8. Evaluation of surface sampling method performance for Bacillus Spores on clean and dirty outdoor surfaces.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mollye C.; Einfeld, Wayne; Boucher, Raymond M.; Brown, Gary Stephen; Tezak, Matthew Stephen

    2011-06-01

    Recovery of Bacillus atrophaeous spores from grime-treated and clean surfaces was measured in a controlled chamber study to assess sampling method performance. Outdoor surfaces investigated by wipe and vacuum sampling methods included stainless steel, glass, marble and concrete. Bacillus atrophaeous spores were used as a surrogate for Bacillus anthracis spores in this study designed to assess whether grime-coated surfaces significantly affected surface sampling method performance when compared to clean surfaces. A series of chamber tests were carried out in which known amounts of spores were allowed to gravitationally settle onto both clean and dirty surfaces. Reference coupons were co-located with test coupons in all chamber experiments to provide a quantitative measure of initial surface concentrations of spores on all surfaces, thereby allowing sampling recovery calculations. Results from these tests, carried out under both low and high humidity conditions, show that spore recovery from grime-coated surfaces is the same as or better than spore recovery from clean surfaces. Statistically significant differences between method performance for grime-coated and clean surfaces were observed in only about half of the chamber tests conducted.

  9. Alternative methods to model frictional contact surfaces using NASTRAN

    Science.gov (United States)

    Hoang, Joseph

    1992-01-01

    Elongated (slotted) holes have been used extensively for the integration of equipment into Spacelab racks. In the past, this type of interface has been modeled assuming that there is not slippage between contact surfaces, or that there is no load transfer in the direction of the slot. Since the contact surfaces are bolted together, the contact friction provides a load path determined by the normal applied force (bolt preload) and the coefficient of friction. Three alternate methods that utilize spring elements, externally applied couples, and stress dependent elements are examined to model the contacted surfaces. Results of these methods are compared with results obtained from methods that use GAP elements and rigid elements.

  10. Lung cancer gene expression database analysis incorporating prior knowledge with support vector machine-based classification method

    Directory of Open Access Journals (Sweden)

    Huang Desheng

    2009-07-01

    Full Text Available Abstract Background A reliable and precise classification is essential for successful diagnosis and treatment of cancer. Gene expression microarrays have provided the high-throughput platform to discover genomic biomarkers for cancer diagnosis and prognosis. Rational use of the available bioinformation can not only effectively remove or suppress noise in gene chips, but also avoid one-sided results of separate experiment. However, only some studies have been aware of the importance of prior information in cancer classification. Methods Together with the application of support vector machine as the discriminant approach, we proposed one modified method that incorporated prior knowledge into cancer classification based on gene expression data to improve accuracy. A public well-known dataset, Malignant pleural mesothelioma and lung adenocarcinoma gene expression database, was used in this study. Prior knowledge is viewed here as a means of directing the classifier using known lung adenocarcinoma related genes. The procedures were performed by software R 2.80. Results The modified method performed better after incorporating prior knowledge. Accuracy of the modified method improved from 98.86% to 100% in training set and from 98.51% to 99.06% in test set. The standard deviations of the modified method decreased from 0.26% to 0 in training set and from 3.04% to 2.10% in test set. Conclusion The method that incorporates prior knowledge into discriminant analysis could effectively improve the capacity and reduce the impact of noise. This idea may have good future not only in practice but also in methodology.

  11. A Strontium-Modified Titanium Surface Produced by a New Method and Its Biocompatibility In Vitro.

    Directory of Open Access Journals (Sweden)

    Chundong Liu

    Full Text Available To present a new and effective method of producing titanium surfaces modified with strontium and to investigate the surface characteristics and in vitro biocompatibility of titanium (Ti surfaces modified with strontium (Sr for bone implant applications.Sr-modified Ti surfaces were produced by sequential treatments with NaOH, strontium acetate, heat and water. The surface characteristics and the concentration of the Sr ions released from the samples were examined. Cell adhesion, morphology and growth were investigated using osteoblasts isolated from the calvaria of neonatal Sprague-Dawley rats. Expression of osteogenesis-related genes and proteins was examined to assess the effect of the Sr-modified Ti surfaces on osteoblasts.The modified titanium surface had a mesh structure with significantly greater porosity, and approximately5.37±0.35at.% of Sr was incorporated into the surface. The hydrophilicity was enhanced by the incorporation of Sr ions and water treatment. The average amounts of Sr released from the Sr-modified plates subjected to water treatment were slight higher than the plates without water treatment. Sr promoted cellular adhesion, spreading and growth compared with untreated Ti surfaces. The Sr-modified Ti plates also promoted expression of osteogenesis-related genes,and expression of OPN and COL-І by osteoblasts. Ti plates heat treated at 700°C showed increased bioactivity in comparison with those treated at 600°C. Water treatment upregulated the expression of osteogenesis-related genes.These results show that Sr-modification of Ti surfaces may improve bioactivity in vitro. Water treatment has enhanced the response of osteoblasts. The Sr-modified Ti heat-treated at 700°C exhibited better bioactivity compared with that heated at 600°C.

  12. A Strontium-Modified Titanium Surface Produced by a New Method and Its Biocompatibility In Vitro.

    Science.gov (United States)

    Liu, Chundong; Zhang, Yanli; Wang, Lichao; Zhang, Xinhua; Chen, Qiuyue; Wu, Buling

    2015-01-01

    To present a new and effective method of producing titanium surfaces modified with strontium and to investigate the surface characteristics and in vitro biocompatibility of titanium (Ti) surfaces modified with strontium (Sr) for bone implant applications. Sr-modified Ti surfaces were produced by sequential treatments with NaOH, strontium acetate, heat and water. The surface characteristics and the concentration of the Sr ions released from the samples were examined. Cell adhesion, morphology and growth were investigated using osteoblasts isolated from the calvaria of neonatal Sprague-Dawley rats. Expression of osteogenesis-related genes and proteins was examined to assess the effect of the Sr-modified Ti surfaces on osteoblasts. The modified titanium surface had a mesh structure with significantly greater porosity, and approximately5.37±0.35at.% of Sr was incorporated into the surface. The hydrophilicity was enhanced by the incorporation of Sr ions and water treatment. The average amounts of Sr released from the Sr-modified plates subjected to water treatment were slight higher than the plates without water treatment. Sr promoted cellular adhesion, spreading and growth compared with untreated Ti surfaces. The Sr-modified Ti plates also promoted expression of osteogenesis-related genes,and expression of OPN and COL-І by osteoblasts. Ti plates heat treated at 700°C showed increased bioactivity in comparison with those treated at 600°C. Water treatment upregulated the expression of osteogenesis-related genes. These results show that Sr-modification of Ti surfaces may improve bioactivity in vitro. Water treatment has enhanced the response of osteoblasts. The Sr-modified Ti heat-treated at 700°C exhibited better bioactivity compared with that heated at 600°C.

  13. Surface-activated joining method for surveillance coupon reconstitution

    International Nuclear Information System (INIS)

    Kaihara, Shoichiro; Nakamura, Terumi

    1993-01-01

    As nuclear power plants approach the end of their license periods and license renewal is contemplated, there is an increasing need to expand the data base of mechanical properties obtainable from archival surveillance specimens. A new joining method for reconstituting broken Charpy specimens is being developed, the objective being to retain the original properties of the material in the process. The new method is called surface-activated joining (SAJ). It is designed to obtain a good junction without applying extra heating and deformation. In particular, the purpose of SAJ is to minimize the width of the heat-affected zone (HAZ) and to decrease the maximum temperature experienced by the specimen during reconsolidation of the two pieces. Generally, machined metal surfaces are contaminated with films of oxide, adsorbed gas, oil, or other vapors that impede bonding of surfaces during joining. However, if surface contamination is removed and the two surfaces are mated as closely as possible, joining can be achieved at low temperatures and modest stress levels. In order to apply the SAJ method, the following requirements must be met: (1) inert atmosphere to protect the surfaces from atmospheric gases and oxidation; (2) removal of the existing contamination layers to activate the surfaces; and (3) method for bringing the two surfaces into very intimate contact prior to joining

  14. Method for Surface Scanning in Medical Imaging and Related Apparatus

    DEFF Research Database (Denmark)

    2015-01-01

    A method and apparatus for surface scanning in medical imaging is provided. The surface scanning apparatus comprises an image source, a first optical fiber bundle comprising first optical fibers having proximal ends and distal ends, and a first optical coupler for coupling an image from the image...

  15. Incorporating vision and hearing tests into aged care assessment: methods and the pilot study.

    Science.gov (United States)

    Jee, Jeanette; Wang, Jie Jin; Rose, Kathryn; Landau, Peter; Lindley, Richard; Mitchell, Paul

    2004-12-01

    Vision and hearing impairments are frequent in older people and may contribute to their reliance on aged care services. This study aims to assess whether incorporating vision and hearing screening into routine aged care assessments and provision of appropriate health care services will influence health outcomes of older individuals. The proposed project is a 2 x 2 factorial design randomized controlled trial. The pilot study recruited 208 participants aged 65+ years attending an aged care assessment center at Westmead Hospital, Sydney, who were randomly allocated to one of four groups: vision and hearing tests, vision tests only, hearing tests only, or neither. Face-to-face interviews with all participants were conducted. Questionnaires included Activity of Daily Living (ADL), 36-item Short-Form health survey (SF-36), Mini-Mental State Exam (MMSE) and questions about use of health care and community support services. Participants will be re-examined after 12 months to assess changes over time in quality-of-life, physical and cognitive function, incident falls and use of health and community aged care services.

  16. 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

  17. Effects of green manure storage and incorporation methods on nitrogen release and N2O emissions after soil application

    DEFF Research Database (Denmark)

    Carter, Mette Sustmann; Sørensen, Peter; Petersen, Søren O.

    2014-01-01

    of plant-available N, nitrous oxide (N2O) fluxes, and soil respiration. Grass-clover silage provided the highest net N release with similar results for the two incorporation methods. Up to one third of the total N content in silage became plant-available during the three months. In contrast, no net N......More efficient use of green manure-derived nitrogen (N) may improve crop yields and reduce environmental impacts in stockless organic arable farming. In this 3-month incubation study, we tested a new strategy where green manure leys are harvested and preserved until the following spring either...... total N. Possibly N2O production via denitrification was stimulated by oxygen-limited conditions near the decomposing silage. In contrast, compost incorporated by harrowing caused net N2O uptake, presumably an effect of reduced mineral N availability in this treatment. Overall, our study revealed...

  18. Interferometric method for measuring high velocities of diffuse surfaces

    International Nuclear Information System (INIS)

    Maron, Y.

    1978-01-01

    An interferometric method for measuring the displacement of diffuse surfaces moving with velocities of a few microsecond is presented. The method utilizes the interference between two light beams reflected from a constant area of the moving surface at two different angles. It enables the detection of high rate velocity variations. Light source of a fairly low temporal coherence and power around 100mW is needed. (author)

  19. 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

    2015-11-01

    To accurately and efficiently reconstruct a continuous surface from noisy point clouds captured by a surface photogrammetry system (VisionRT). 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. On phantom point clouds, their method achieved submillimeter

  20. A general method to incorporate metal nanoparticles in zeolites and zeotypes

    DEFF Research Database (Denmark)

    2015-01-01

    Disclosed herein is a method for producing a zeolite, zeolite-like or zeotype structure with selective formation of metal, metal oxide or metal sulphide nanoparticles and/or clusters inside the zeolite, zeolite-like or zeotype structure.......Disclosed herein is a method for producing a zeolite, zeolite-like or zeotype structure with selective formation of metal, metal oxide or metal sulphide nanoparticles and/or clusters inside the zeolite, zeolite-like or zeotype structure....

  1. Influence of manganese incorporation on structure, surface and As(III)/As(V) removal capacity of iron oxy-hydroxides

    Science.gov (United States)

    Tresintsi, Sofia; Simeonidis, Konstantinos; Mitrakas, Manassis

    2013-04-01

    Iron oxy-hydroxides are well defined As(V) adsorbents dominating in water treatment market. The main drawback of these adsorbents, as well as of all commercial one, is their significantly low adsorption capacity for As(III). A breakthrough for improving As(III) adsorption of iron oxy-hydroxides may come by the MnO2incorporation. However, MnO2 decreases the total arsenic capacity proportionally to its percentage since its efficiency for As(V) is much lower than that of an iron oxy-hydroxide. It is concluded that an ideal adsorbent capable for high and simultaneous As(III) and As(V) removal should be consisted of a binary Fe(III)-Mn(IV) oxy-hydroxide both efficient for As(III) oxidation, due to Mn(IV) presence, and capture of As(V) due to a high positively surface charge density. This work studies the optimum parameters at the synthesis of single Fe and binary Fe/Mn oxy-hydroxides in a continuous flow kilogram-scale production reactor through the precipitation of FeSO4 in the pH range 3-12, under intense oxidative conditions using H2O2/KMnO4, that maximize arsenic adsorption. The evaluation of their efficiency was based on its As(III) and As(V) adsorption capacity (Q10-index) at equilibrium concentration equal to drinking water regulation limit (Ce= 10 μg/L) in NSF challenge water. The pH of synthesis was found to decisively affect, the structure, surface configuration and Q10-index. As a result, both single Fe and binary Fe/Mn oxy-hydroxides prepared at pH 4, which consist of schwertmannite and Mn(IV)-feroxyhyte respectively, were qualified according to their highest Q10-index of 13±0.5 μg As(V)/ mg for a residual arsenic concentration of 10 μg/L at an equilibrium pH 7. The high surface charge and the activation of an ion-exchange mechanism between SO42- adsorbed in the Stern layer and arsenate ions were found to significantly contribute to the increased adsorption capacity. The Q10-index for As(III) of Fe/Mn adsorbent at equilibrium pH 7 was 6.7 μg/mg, which

  2. Comparison study of intraoperative surface acquisition methods for surgical navigation.

    Science.gov (United States)

    Simpson, Amber L; Burgner, Jessica; Glisson, Courtenay L; Herrell, S Duke; Ma, Burton; Pheiffer, Thomas S; Webster, Robert J; Miga, Michael I

    2013-04-01

    Soft-tissue image-guided interventions often require the digitization of organ surfaces for providing correspondence from medical images to the physical patient in the operating room. In this paper, the effect of several inexpensive surface acquisition techniques on target registration error and surface registration error (SRE) for soft tissue is investigated. A systematic approach is provided to compare image-to-physical registrations using three different methods of organ spatial digitization: 1) a tracked laser-range scanner (LRS), 2) a tracked pointer, and 3) a tracked conoscopic holography sensor (called a conoprobe). For each digitization method, surfaces of phantoms and biological tissues were acquired and registered to CT image volume counterparts. A comparison among these alignments demonstrated that registration errors were statistically smaller with the conoprobe than the tracked pointer and LRS (pconoscopic holography) of digitizing surfaces for clinical usage. The tracked conoscopic holography device outperforms LRS acquisitions with respect to registration accuracy.

  3. Laser method of acoustical emission control from vibrating surfaces

    Science.gov (United States)

    Motyka, Zbigniew

    2013-01-01

    For limitation of the noise in environment, the necessity occurs of determining and location of sources of sounds emitted from surfaces of many machines and devices, assuring in effect the possibility of suitable constructional changes implementation, targeted at decreasing of their nuisance. In the paper, the results of tests and calculations are presented for plane surface sources emitting acoustic waves. The tests were realized with the use of scanning laser vibrometer which enabled remote registration and the spectral analysis of the surfaces vibrations. The known hybrid digital method developed for determination of sound wave emission from such surfaces divided into small finite elements was slightly modified by distinguishing the phase correlations between such vibrating elements. The final method being developed may find use in wide range of applications for different forms of vibrations of plane surfaces.

  4. A GPU-based mipmapping method for water surface visualization

    Science.gov (United States)

    Li, Hua; Quan, Wei; Xu, Chao; Wu, Yan

    2018-03-01

    Visualization of water surface is a hot topic in computer graphics. In this paper, we presented a fast method to generate wide range of water surface with good image quality both near and far from the viewpoint. This method utilized uniform mesh and Fractal Perlin noise to model water surface. Mipmapping technology was enforced to the surface textures, which adjust the resolution with respect to the distance from the viewpoint and reduce the computing cost. Lighting effect was computed based on shadow mapping technology, Snell's law and Fresnel term. The render pipeline utilizes a CPU-GPU shared memory structure, which improves the rendering efficiency. Experiment results show that our approach visualizes water surface with good image quality at real-time frame rates performance.

  5. Displacement Forecasting Method in Brittle Crack Surrounding Rock Under Excavation Unloading Incorporating Opening Deformation

    Science.gov (United States)

    Li, X. J.; Yang, W. M.; Wang, L. G.; Butler, I. B.

    2014-11-01

    Splitting failure, which is recognized as a special engineering geology phenomenon, occurs continually in the brittle rock mass of caverns during underground excavation. In this paper, a splitting model of linear slippage crack groups is built with fracture mechanics, energy analysis, and crack extension theories. Considering intrinsic cracks in rock mass and change of outer stress, intrinsic cracks propagate into macroscopical splitting cracks that are approximately parallel to the side wall of caverns. The splitting criterion of cavern rock mass and the method for predicting displacement in view of splitting opening displacement are proposed. In the end, the forecasting method is applied to the Jinping-I Hydropower Station, underground caverns engineering in China, the splitting failure zone and forecasting displacement are accordant with the monitoring data. The new forecasting displacement method is proven to contribute to the construction of similar underground caverns.

  6. Ultrasound-assisted surface treatment of ZrO2with BSA and incorporating in PVC to improve the properties of the obtained nanocomposites: Fabrication and characterization.

    Science.gov (United States)

    Mallakpour, Shadpour; Hajjari, Zahra

    2018-03-01

    This paper describes the preparation of poly(vinyl chloride) (PVC) nanocomposites (NCs) reinforced with modified zirconia (ZrO 2 ) nanoparticles (NPs). The ZrO 2 NPs were defined as efficient filler for PVC NCs. For achieving the best dispersion and improvement of properties, the surface of ZrO 2 NPs was modified by Bovine Serum Albumin (BSA). Carboxylic acids and amines are important functional groups of BSA which handle the grafting BSA on the surface of ZrO 2 NPs. The PVC/ZrO 2 -BSA NCs were fabricated by incorporation of various amounts of the ZrO 2 -BSA NPs (3, 6 and 9wt%) into PVC matrix. All the above processes were accomplished by ultrasonication asa green and environmentally-friendly method. Also, the magnetic and mechanical stirrer was used for the preparation of samples but the results are not suitable and the aggregation was observed which indicated the use of ultrasonic irradiation is the best method for the preparation of NC. The products were characterized by Fourier transform infrared spectroscopy, Transmission electron microscopy, Field emission scanning electron microscopy, X-ray diffraction, Thermogravimetric analysis, Ultraviolet-visible spectroscopy, photoluminescence spectroscopy, energy dispersive X-ray spectroscopy, wettability, and mechanical tests. The achieved PVC/ZrO 2 -BSA NCs showed high thermal stability, good mechanical, optical and wettability properties compared to the pure PVC. In addition, among the obtained NCs, the PVC/ZrO 2 -BSA NC 6wt% showed the best improvement. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Calcification in the staghorn coral Acropora acuminata: variations in apparent skeletal incorporation of radioisotopes due to different methods of processing

    International Nuclear Information System (INIS)

    Crossland, C.J.; Barnes, D.J.

    1977-01-01

    Pieces of branch from the staghorn coral Acropora acuminata were incubated with 45 CaCl 2 and NaH 14 CO 3 under identical conditions in the light or in the dark. Specimens were then processed in different ways. All specimens were placed in N KOH to digest tissues. Some were placed in KOH immediately after incubation; others were placed in KOH after 2 h washing, or after 2 h extraction with methanol-chloroform-water. Specimens were washed in running fresh water or running seawater; some were killed in liquid N 2 before washing. Radioactivity associated with skeleton and tissues was determined. The method of processing profoundly affected the results. In dark incubations, there was up to a four-fold difference in apparent skeletal incorporation of 45 Ca ++ between average values obtained for the different treatments. For 14 C incorporation, there was a difference of up to 2.5 times. In light incubations, skeletal incorporation of both radioisotopes showed a two-fold difference between high and low average values obtained for the different treatments. (orig.) [de

  8. Hazardous Waste Cleanup: Methode Electronics Incorporated in Willingboro Township, New Jersey

    Science.gov (United States)

    The former Methode Electronics facility is a 3.06 acre site located at; 10 Industrial Drive, Willingboro Township, Burlington County, New Jersey, approximately two miles east of the Delaware River, one-half mile southeast of route 130, and one-half mile

  9. A corrected model for static and dynamic electromechanical instability of narrow nanotweezers: Incorporation of size effect, surface layer and finite dimensions

    Science.gov (United States)

    Koochi, Ali; Hosseini-Toudeshky, Hossein; Abadyan, Mohamadreza

    2018-03-01

    Herein, a corrected theoretical model is proposed for modeling the static and dynamic behavior of electrostatically actuated narrow-width nanotweezers considering the correction due to finite dimensions, size dependency and surface energy. The Gurtin-Murdoch surface elasticity in conjunction with the modified couple stress theory is employed to consider the coupling effect of surface stresses and size phenomenon. In addition, the model accounts for the external force corrections by incorporating the impact of narrow width on the distribution of Casimir attraction, van der Waals (vdW) force and the fringing field effect. The proposed model is beneficial for the precise modeling of the narrow nanotweezers in nano-scale.

  10. Classification of reflected signals from cavitated tooth surfaces using an artificial intelligence technique incorporating a fiber optic displacement sensor

    Science.gov (United States)

    Rahman, Husna Abdul; Harun, Sulaiman Wadi; Arof, Hamzah; Irawati, Ninik; Musirin, Ismail; Ibrahim, Fatimah; Ahmad, Harith

    2014-05-01

    An enhanced dental cavity diameter measurement mechanism using an intensity-modulated fiber optic displacement sensor (FODS) scanning and imaging system, fuzzy logic as well as a single-layer perceptron (SLP) neural network, is presented. The SLP network was employed for the classification of the reflected signals, which were obtained from the surfaces of teeth samples and captured using FODS. Two features were used for the classification of the reflected signals with one of them being the output of a fuzzy logic. The test results showed that the combined fuzzy logic and SLP network methodology contributed to a 100% classification accuracy of the network. The high-classification accuracy significantly demonstrates the suitability of the proposed features and classification using SLP networks for classifying the reflected signals from teeth surfaces, enabling the sensor to accurately measure small diameters of tooth cavity of up to 0.6 mm. The method remains simple enough to allow its easy integration in existing dental restoration support systems.

  11. Monitoring of thorium incorporation by thoron in breath measurement: technical design of a routine method

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmenger, A.; Riedel, W.; Scheler, R.; Brose, J

    1998-07-01

    A method for measurement of thoron ({sup 220}Rn) in exhaled air is being developed for routine monitoring of inhaled thorium intakes. Decay products of thoron ({sup 216}Po and {sup 212}Pb) are collected electrostatically and their progeny are measured subsequently by alpha spectrometry. With the equipment presently used the influence of parameters such as chamber volume, collection head geometry and position, supplied high voltage, flow rate and subsequent counting time on the collection efficiency have been investigated. The overall efficiency is approximately 8% at the moment. This makes the method capable of detecting thorium in lungs at an amount of 3% of an ALI (Annual Limit on Intake), for example corresponding to 0.9 Bq of {sup 232}Th (class W), as required by the German radiation protection monitoring guidelines. (author)

  12. Sequence-based antigenic change prediction by a sparse learning method incorporating co-evolutionary information.

    Directory of Open Access Journals (Sweden)

    Jialiang Yang

    Full Text Available Rapid identification of influenza antigenic variants will be critical in selecting optimal vaccine candidates and thus a key to developing an effective vaccination program. Recent studies suggest that multiple simultaneous mutations at antigenic sites accumulatively enhance antigenic drift of influenza A viruses. However, pre-existing methods on antigenic variant identification are based on analyses from individual sites. Because the impacts of these co-evolved sites on influenza antigenicity may not be additive, it will be critical to quantify the impact of not only those single mutations but also multiple simultaneous mutations or co-evolved sites. Here, we developed and applied a computational method, AntigenCO, to identify and quantify both single and co-evolutionary sites driving the historical antigenic drifts. AntigenCO achieved an accuracy of up to 90.05% for antigenic variant prediction, significantly outperforming methods based on single sites. AntigenCO can be useful in antigenic variant identification in influenza surveillance.

  13. Application of Ultrasonic Sensors in Road Surface Condition Distinction Methods

    Directory of Open Access Journals (Sweden)

    Shota Nakashima

    2016-10-01

    Full Text Available The number of accidents involving elderly individuals has been increasing with the increase of the aging population, posing increasingly serious challenges. Most accidents are caused by reduced judgment and physical abilities, which lead to severe consequences. Therefore, studies on support systems for elderly and visually impaired people to improve the safety and quality of daily life are attracting considerable attention. In this study, a road surface condition distinction method using reflection intensities obtained by an ultrasonic sensor was proposed. The proposed method was applied to movement support systems for elderly and visually impaired individuals to detect dangerous road surfaces and give an alarm. The method did not perform well in previous studies of puddle detection, because the alert provided by the method did not enable users to avoid puddles. This study extended the method proposed by previous studies with respect to puddle detection ability. The findings indicate the effectiveness of the proposed method by considering four road surface conditions. The proposed method could detect puddle conditions. The effectiveness of the proposed method was verified in all four conditions, since users could differentiate between road surface conditions and classify the conditions as either safe or dangerous.

  14. METHOD FOR FABRICATING NANOSCALE PATTERNS ON A SURFACE

    DEFF Research Database (Denmark)

    2000-01-01

    A novel method to fabricate nanoscale pits on Au(111) surfaces in contact with aqueous solution is claimed. The method uses in situ electrochemical scanning tunnelling microscopy with independent electrochemical substrate and tip potential control and very small bias voltages. This is significantly...

  15. Europium incorporated into titanium oxide by the sol-gel method

    Directory of Open Access Journals (Sweden)

    Lucas Alonso Rocha

    2005-09-01

    Full Text Available In this work titanium sol was prepared from tetraethylorthotitanate (TEOT in ethanol, stabilized with beta-diketonate 2,4 pentanedione in molar ratio 1:1 homogenized by magnetic stirring, europium ion was add as structural probe. The xerogels were heat treated at 500, 750 and 1000 °C and the characterization was realized by x-ray diffraction (XRD, transmission electron microscopy (TEM, thermogravimetric analysis (TGA/DSC and photoluminescence (PL. The excitation spectra of Eu (III ion present maximum in 394 nm correspondent to 5L6 level and emission spectra present bands characteristic transitions arising from the 5 D0 -> 7F J (J = 0, 1, 2, 3, 4 manifolds to samples treat at 500 and 750 °C. The Eu (III emission disappear, when heated at 1000 °C, probably due to phase transition anatase to rutile and migrations of ions to the external surface that was proved by x-ray diffraction, transmission electronic microscopy and the thermogravimetric analyses of xerogels.

  16. Extrapolation of extreme sea levels: incorporation of Over-Threshold-Modeling to the Joint Probability Method

    Science.gov (United States)

    Mazas, Franck; Hamm, Luc; Kergadallan, Xavier

    2013-04-01

    In France, the storm Xynthia of February 27-28th, 2010 reminded engineers and stakeholders of the necessity for an accurate estimation of extreme sea levels for the risk assessment in coastal areas. Traditionally, two main approaches exist for the statistical extrapolation of extreme sea levels: the direct approach performs a direct extrapolation on the sea level data, while the indirect approach carries out a separate analysis of the deterministic component (astronomical tide) and stochastic component (meteorological residual, or surge). When the tidal component is large compared with the surge one, the latter approach is known to perform better. In this approach, the statistical extrapolation is performed on the surge component then the distribution of extreme seal levels is obtained by convolution of the tide and surge distributions. This model is often referred to as the Joint Probability Method. Different models from the univariate extreme theory have been applied in the past for extrapolating extreme surges, in particular the Annual Maxima Method (AMM) and the r-largest method. In this presentation, we apply the Peaks-Over-Threshold (POT) approach for declustering extreme surge events, coupled with the Poisson-GPD model for fitting extreme surge peaks. This methodology allows a sound estimation of both lower and upper tails of the stochastic distribution, including the estimation of the uncertainties associated to the fit by computing the confidence intervals. After convolution with the tide signal, the model yields the distribution for the whole range of possible sea level values. Particular attention is paid to the necessary distinction between sea level values observed at a regular time step, such as hourly, and sea level events, such as those occurring during a storm. Extremal indexes for both surges and levels are thus introduced. This methodology will be illustrated with a case study at Brest, France.

  17. Quantifying Uncertainty in Near Surface Electromagnetic Imaging Using Bayesian Methods

    Science.gov (United States)

    Blatter, D. B.; Ray, A.; Key, K.

    2017-12-01

    Geoscientists commonly use electromagnetic methods to image the Earth's near surface. Field measurements of EM fields are made (often with the aid an artificial EM source) and then used to infer near surface electrical conductivity via a process known as inversion. In geophysics, the standard inversion tool kit is robust and can provide an estimate of the Earth's near surface conductivity that is both geologically reasonable and compatible with the measured field data. However, standard inverse methods struggle to provide a sense of the uncertainty in the estimate they provide. This is because the task of finding an Earth model that explains the data to within measurement error is non-unique - that is, there are many, many such models; but the standard methods provide only one "answer." An alternative method, known as Bayesian inversion, seeks to explore the full range of Earth model parameters that can adequately explain the measured data, rather than attempting to find a single, "ideal" model. Bayesian inverse methods can therefore provide a quantitative assessment of the uncertainty inherent in trying to infer near surface conductivity from noisy, measured field data. This study applies a Bayesian inverse method (called trans-dimensional Markov chain Monte Carlo) to transient airborne EM data previously collected over Taylor Valley - one of the McMurdo Dry Valleys in Antarctica. Our results confirm the reasonableness of previous estimates (made using standard methods) of near surface conductivity beneath Taylor Valley. In addition, we demonstrate quantitatively the uncertainty associated with those estimates. We demonstrate that Bayesian inverse methods can provide quantitative uncertainty to estimates of near surface conductivity.

  18. Optical description and design method with annularly stitched aspheric surface.

    Science.gov (United States)

    Cheng, De-Wen; Chen, Xue-Jiao; Xu, Chen; Hu, Yuan; Wang, Yong-Tian

    2015-12-01

    The relentless pressure for designs with new optical functions, small volume, and light weight has greatly increased the importance of aspheric surfaces. In this paper, we propose an annularly stitched aspheric surface (ASAS) description method to increase the freedom and flexibility of imaging system design. The rotationally symmetric ASAS consists of a circular central zone and one or more annular zones. Two neighboring zones are constrained to have the same derivatives on their joint curve, and this means the ASAS is C1 continuous. This finding is proved and verified by the mathematical deduction of the surface formulas. Two optimization strategies and two design methods with the C1 continuous constraints are also discussed. This surface can greatly facilitate the design and even achieve some previously impossible designs without increasing the fabrication difficulty. Two different systems with the proposed ASAS are optimized and the results are presented. The design results verified the practicability of the ASAS.

  19. Multiscale Finite Element Methods for Flows on Rough Surfaces

    KAUST Repository

    Efendiev, Yalchin

    2013-01-01

    In this paper, we present the Multiscale Finite Element Method (MsFEM) for problems on rough heterogeneous surfaces. We consider the diffusion equation on oscillatory surfaces. Our objective is to represent small-scale features of the solution via multiscale basis functions described on a coarse grid. This problem arises in many applications where processes occur on surfaces or thin layers. We present a unified multiscale finite element framework that entails the use of transformations that map the reference surface to the deformed surface. The main ingredients of MsFEM are (1) the construction of multiscale basis functions and (2) a global coupling of these basis functions. For the construction of multiscale basis functions, our approach uses the transformation of the reference surface to a deformed surface. On the deformed surface, multiscale basis functions are defined where reduced (1D) problems are solved along the edges of coarse-grid blocks to calculate nodalmultiscale basis functions. Furthermore, these basis functions are transformed back to the reference configuration. We discuss the use of appropriate transformation operators that improve the accuracy of the method. The method has an optimal convergence if the transformed surface is smooth and the image of the coarse partition in the reference configuration forms a quasiuniform partition. In this paper, we consider such transformations based on harmonic coordinates (following H. Owhadi and L. Zhang [Comm. Pure and Applied Math., LX(2007), pp. 675-723]) and discuss gridding issues in the reference configuration. Numerical results are presented where we compare the MsFEM when two types of deformations are used formultiscale basis construction. The first deformation employs local information and the second deformation employs a global information. Our numerical results showthat one can improve the accuracy of the simulations when a global information is used. © 2013 Global-Science Press.

  20. Dynamic Parameters in Preparing Chitosan Nanoparticles with Incorporation Method Using Novel Drug Delivery Systems

    Directory of Open Access Journals (Sweden)

    S.Mojtaba Taghizadeh

    2013-01-01

    Full Text Available Polymeric nanoparticles with biodegradable and biocompatible polymers are good candidates in peptide drugs delivery systems. In this study, we success- fully prepared chitosan nanoparticles including salicylic acid as a model drugby emulsion cross-linking "in oil" method. The various dynamic parameters are considered, including the speed of stirrer, the duration of injecting the aqueous phase into oil phase and the condition of precipitation of particles. It is found that the optimum conditions are achieved at 2000 rpm when the aqueous phase is added within 30 min into the oil phase. According to optimum conditions the nanoparticles of chitosan (the peak of size distribution in 100 nm were prepared and the drug content and the release behavior were estimated. The results demonstrate, that the drug content ofnanoparticles is 35% (w/w. The release behavior of nanoparticles during first 4 hour conform best to Higuchi model and thereafter up to maximum 48 h the amount of drug released is negligible.

  1. A method for estimating tokamak poloidal field coil currents which incorporates engineering constraints

    International Nuclear Information System (INIS)

    Stewart, W.A.

    1990-05-01

    This thesis describes the development of a design tool for the poloidal field magnet system of a tokamak. Specifically, an existing program for determining the poloidal field coil currents has been modified to: support the general case of asymmetric equilibria and coil sets, determine the coil currents subject to constraints on the maximum values of those currents, and determine the coil currents subject to limits on the forces those coils may carry. The equations representing the current limits and coil force limits are derived and an algorithm based on Newton's method is developed to determine a set of coil currents which satisfies those limits. The resulting program allows the designer to quickly determine whether or not a given coil set is capable of supporting a given equilibrium. 25 refs

  2. High-directional light source using photon recycling with a retro-reflective Dome incorporated with a textured LED die surface.

    Science.gov (United States)

    Sun, Ching-Cherng; Chung, Shuang-Chao; Yang, Shuang-Hao; Yu, Yeh-Wei; Chien, Wei-Ting; Chen, Huang-Kuen; Chen, Shih-Peng

    2013-07-29

    This paper demonstrates a novel retro-reflective dome that enhances the directionality of a light emitting diode (LED) by recycling photons reflected by a textured LED die surface. A simulation model is developed to describe both the photon recycling process within the dome and the role of specific pyramid patterns on the top surface of the LED die. Advanced simulations showed that a perfectly polished surface with 100% reflectivity potentially enhances the directionality of the dome by 340%, 250%, and 240% using reflective domes with 10°, 20°, and 30° light cones, respectively. In the experiment, the directionality of the domes exhibiting surface imperfections is enhanced by approximately 160%, 150%, and 130% using 10°, 20°, and 30° light cones, respectively. By incorporating a textured top surface on the LED die, the proposed dome effectively increases the directionality of the LED light source.

  3. Method for Constructing Composite Response Surfaces by Combining Neural Networks with other Interpolation or Estimation Techniques

    Science.gov (United States)

    Rai, Man Mohan (Inventor); Madavan, Nateri K. (Inventor)

    2003-01-01

    A method and system for design optimization that incorporates the advantages of both traditional response surface methodology (RSM) and neural networks is disclosed. The present invention employs a unique strategy called parameter-based partitioning of the given design space. In the design procedure, a sequence of composite response surfaces based on both neural networks and polynomial fits is used to traverse the design space to identify an optimal solution. The composite response surface has both the power of neural networks and the economy of low-order polynomials (in terms of the number of simulations needed and the network training requirements). The present invention handles design problems with many more parameters than would be possible using neural networks alone and permits a designer to rapidly perform a variety of trade-off studies before arriving at the final design.

  4. Experimental Method for Measuring Dust Load on Surfaces in Rooms

    DEFF Research Database (Denmark)

    Lengweiler, Philip; Nielsen, Peter V.; Moser, Alfred

    , there is a need for better understanding of the mechanism of dust deposition and resuspension. With the presented experimental setup, the dust load on surfaces in a channel can be measured as a function of the environmental and surface conditions and the type of particles under controlled laboratory conditions.......A new experimental setup to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airborne dust concentration considerably. As a basis for developing methods to eliminate dust-related problems in rooms...

  5. Incorporating forcing terms in cascaded lattice Boltzmann approach by method of central moments.

    Science.gov (United States)

    Premnath, Kannan N; Banerjee, Sanjoy

    2009-09-01

    Cascaded lattice Boltzmann method (cascaded-LBM) employs a class of collision operators aiming to stabilize computations and remove certain modeling artifacts for simulation of fluid flow on lattice grids with sizes arbitrarily larger than the smallest physical dissipation length scale [Geier, Phys. Rev. E 63, 066705 (2006)]. It achieves this and distinguishes from other collision operators, such as in the standard single or multiple relaxation-time approaches, by performing relaxation process due to collisions in terms of moments shifted by the local hydrodynamic fluid velocity, i.e., central moments, in an ascending order by order at different relaxation rates. In this paper, we propose and derive source terms in the cascaded-LBM to represent the effect of external or internal forces on the dynamics of fluid motion. This is essentially achieved by matching the continuous form of the central moments of the source or forcing terms with its discrete version. Different forms of continuous central moments of sources, including one that is obtained from a local Maxwellian, are considered in this regard. As a result, the forcing terms obtained in this formulation are Galilean invariant by construction. To alleviate lattice artifacts due to forcing terms in the emergent macroscopic fluid equations, they are proposed as temporally semi-implicit and second order, and the implicitness is subsequently effectively removed by means of a transformation to facilitate computation. It is shown that the impressed force field influences the cascaded collision process in the evolution of the transformed distribution function. The method of central moments along with the associated orthogonal properties of the moment basis completely determines the analytical expressions for the source terms as a function of the force and macroscopic velocity fields. In contrast to the existing forcing schemes, it is found that they involve higher-order terms in velocity space. It is shown that the

  6. Noise robustness of interferometric surface topography evaluation methods. Correlogram correlation

    Science.gov (United States)

    Kiselev, Ilia; Kiselev, Egor I.; Drexel, Michael; Hauptmannl, Michael

    2017-12-01

    Different surface height estimation methods are differently affected by interferometric noise. From a theoretical analysis we obtain height variance estimators for the methods. The estimations allow us to rigorously compare the noise robustness of popular evaluation algorithms. The envelope methods have the highest variances and hence the lowest noise resistances. The noise robustness improves from the envelope to the phase methods, but a technique involving the correlation of correlograms is superior even to the latter. We dwell on some details of this correlogram correlation method and the range of its application.

  7. An Adaptive Thresholding Method for BTV Estimation Incorporating PET Reconstruction Parameters: A Multicenter Study of the Robustness and the Reliability

    Directory of Open Access Journals (Sweden)

    M. Brambilla

    2015-01-01

    Full Text Available Objective. The aim of this work was to assess robustness and reliability of an adaptive thresholding algorithm for the biological target volume estimation incorporating reconstruction parameters. Method. In a multicenter study, a phantom with spheres of different diameters (6.5–57.4 mm was filled with 18F-FDG at different target-to-background ratios (TBR: 2.5–70 and scanned for different acquisition periods (2–5 min. Image reconstruction algorithms were used varying number of iterations and postreconstruction transaxial smoothing. Optimal thresholds (TS for volume estimation were determined as percentage of the maximum intensity in the cross section area of the spheres. Multiple regression techniques were used to identify relevant predictors of TS. Results. The goodness of the model fit was high (R2: 0.74–0.92. TBR was the most significant predictor of TS. For all scanners, except the Gemini scanners, FWHM was an independent predictor of TS. Significant differences were observed between scanners of different models, but not between different scanners of the same model. The shrinkage on cross validation was small and indicative of excellent reliability of model estimation. Conclusions. Incorporation of postreconstruction filtering FWHM in an adaptive thresholding algorithm for the BTV estimation allows obtaining a robust and reliable method to be applied to a variety of different scanners, without scanner-specific individual calibration.

  8. A Fully Automated and Robust Method to Incorporate Stamping Data in Crash, NVH and Durability Analysis

    Science.gov (United States)

    Palaniswamy, Hariharasudhan; Kanthadai, Narayan; Roy, Subir; Beauchesne, Erwan

    2011-08-01

    Crash, NVH (Noise, Vibration, Harshness), and durability analysis are commonly deployed in structural CAE analysis for mechanical design of components especially in the automotive industry. Components manufactured by stamping constitute a major portion of the automotive structure. In CAE analysis they are modeled at a nominal state with uniform thickness and no residual stresses and strains. However, in reality the stamped components have non-uniformly distributed thickness and residual stresses and strains resulting from stamping. It is essential to consider the stamping information in CAE analysis to accurately model the behavior of the sheet metal structures under different loading conditions. Especially with the current emphasis on weight reduction by replacing conventional steels with aluminum and advanced high strength steels it is imperative to avoid over design. Considering this growing need in industry, a highly automated and robust method has been integrated within Altair Hyperworks® to initialize sheet metal components in CAE models with stamping data. This paper demonstrates this new feature and the influence of stamping data for a full car frontal crash analysis.

  9. Adsorption, Desorption, Surface Diffusion, Lattice Defect Formation, and Kink Incorporation Processes of Particles on Growth Interfaces of Colloidal Crystals with Attractive Interactions

    Directory of Open Access Journals (Sweden)

    Yoshihisa Suzuki

    2016-07-01

    Full Text Available Good model systems are required in order to understand crystal growth processes because, in many cases, precise incorporation processes of atoms or molecules cannot be visualized easily at the atomic or molecular level. Using a transmission-type optical microscope, we have successfully observed in situ adsorption, desorption, surface diffusion, lattice defect formation, and kink incorporation of particles on growth interfaces of colloidal crystals of polystyrene particles in aqueous sodium polyacrylate solutions. Precise surface transportation and kink incorporation processes of the particles into the colloidal crystals with attractive interactions were observed in situ at the particle level. In particular, contrary to the conventional expectations, the diffusion of particles along steps around a two-dimensional island of the growth interface was not the main route for kink incorporation. This is probably due to the number of bonds between adsorbed particles and particles in a crystal; the number exceeds the limit at which a particle easily exchanges its position to the adjacent one along the step. We also found novel desorption processes of particles from steps to terraces, attributing them to the assistance of attractive forces from additionally adsorbing particles to the particles on the steps.

  10. 3D electric field calculation with surface charge method

    International Nuclear Information System (INIS)

    Yamada, S.

    1992-01-01

    This paper describes an outline and some examples of three dimensional electric field calculations with a computer code developed at NIRS. In the code, a surface charge method is adopted because of it's simplicity in the mesh establishing procedure. The charge density in a triangular mesh is assumed to distribute with a linear function of the position. The electric field distribution is calculated for a pair of drift tubes with the focusing fingers on the opposing surfaces. The field distribution in an acceleration gap is analyzed with a Fourier-Bessel series expansion method. The calculated results excellently reproduces the measured data with a magnetic model. (author)

  11. Multifunctional, Micropipette-based Method for Incorporation And Stimulation of Bacterial Mechanosensitive Ion Channels in Droplet Interface Bilayers.

    Science.gov (United States)

    Najem, Joseph S; Dunlap, Myles D; Yasmann, Anthony; Freeman, Eric C; Grant, John W; Sukharev, Sergei; Leo, Donald J

    2015-11-19

    MscL, a large conductance mechanosensitive channel (MSC), is a ubiquitous osmolyte release valve that helps bacteria survive abrupt hypo-osmotic shocks. It has been discovered and rigorously studied using the patch-clamp technique for almost three decades. Its basic role of translating tension applied to the cell membrane into permeability response makes it a strong candidate to function as a mechanoelectrical transducer in artificial membrane-based biomolecular devices. Serving as building blocks to such devices, droplet interface bilayers (DIBs) can be used as a new platform for the incorporation and stimulation of MscL channels. Here, we describe a micropipette-based method to form DIBs and measure the activity of the incorporated MscL channels. This method consists of lipid-encased aqueous droplets anchored to the tips of two opposing (coaxially positioned) borosilicate glass micropipettes. When droplets are brought into contact, a lipid bilayer interface is formed. This technique offers control over the chemical composition and the size of each droplet, as well as the dimensions of the bilayer interface. Having one of the micropipettes attached to a harmonic piezoelectric actuator provides the ability to deliver a desired oscillatory stimulus. Through analysis of the shapes of the droplets during deformation, the tension created at the interface can be estimated. Using this technique, the first activity of MscL channels in a DIB system is reported. Besides MS channels, activities of other types of channels can be studied using this method, proving the multi-functionality of this platform. The method presented here enables the measurement of fundamental membrane properties, provides a greater control over the formation of symmetric and asymmetric membranes, and is an alternative way to stimulate and study mechanosensitive channels.

  12. Efficiency enhancement of fluorescence blue organic light-emitting diodes by incorporating Ag nanoparticles layers due to a localized surface plasmon

    Science.gov (United States)

    Nam, Minwoo; Chung, Nak-Kwan; Shim, Seob; Yun, Ju-Young; Kim, Jin-Tae; Pyo, Sung Gyu

    2017-09-01

    Enhanced electroluminescence in blue organic light-emitting diodes (OLEDs) is obtained by incorporating Ag nanoparticles (NPs) into hole injection layer of poly(3,4- ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS). The absorption peak of the localized surface plasmons (LSPs) introduced by the 60 nm Ag NPs matches the emission wavelength of the blue OLEDs were matched at wavelength of 442 nm. In addition, to maximize their coupling and to prevent the quenching of the emission, the distance between surface plasmons (SPs) around NPs and organic fluorophores is optimized. Finally, the emission intensity and the current efficiency of diode with Ag NPs were increased by 19% and 18%, respectively.

  13. A NEW HIGH RESOLUTION OPTICAL METHOD FOR OBTAINING THE TOPOGRAPHY OF FRACTURE SURFACES IN ROCKS

    Directory of Open Access Journals (Sweden)

    Steven Ogilvie

    2011-05-01

    Full Text Available Surface roughness plays a major role in the movement of fluids through fracture systems. Fracture surface profiling is necessary to tune the properties of numerical fractures required in fluid flow modelling to those of real rock fractures. This is achieved using a variety of (i mechanical and (ii optical techniques. Stylus profilometry is a popularly used mechanical method and can measure surface heights with high precision, but only gives a good horizontal resolution in one direction on the fracture plane. This method is also expensive and simultaneous coverage of the surface is not possible. Here, we describe the development of an optical method which images cast copies of rough rock fractures using in-house developed hardware and image analysis software (OptiProf™ that incorporates image improvement and noise suppression features. This technique images at high resolutions, 15-200 μm for imaged areas of 10 × 7.5 mm and 100 × 133 mm, respectively and a similar vertical resolution (15 μm for a maximum topography of 4 mm. It uses in-house developed hardware and image analysis (OptiProf™ software and is cheap and non-destructive, providing continuous coverage of the fracture surface. The fracture models are covered with dye and fluid thicknesses above the rough surfaces converted into topographies using the Lambert-Beer Law. The dye is calibrated using 2 devices with accurately known thickness; (i a polycarbonate tile with wells of different depths and (ii a wedge-shaped vial made from silica glass. The data from each of the two surfaces can be combined to provide an aperture map of the fracture for the scenario where the surfaces touch at a single point or any greater mean aperture. The topography and aperture maps are used to provide data for the generation of synthetic fractures, tuned to the original fracture and used in numerical flow modelling.

  14. Workgroup Report: Incorporating In Vitro Alternative Methods for Developmental Neurotoxicity into International Hazard and Risk Assessment Strategies

    Science.gov (United States)

    Coecke, Sandra; Goldberg, Alan M; Allen, Sandra; Buzanska, Leonora; Calamandrei, Gemma; Crofton, Kevin; Hareng, Lars; Hartung, Thomas; Knaut, Holger; Honegger, Paul; Jacobs, Miriam; Lein, Pamela; Li, Abby; Mundy, William; Owen, David; Schneider, Steffen; Silbergeld, Ellen; Reum, Torsten; Trnovec, Tomas; Monnet-Tschudi, Florianne; Bal-Price, Anna

    2007-01-01

    This is the report of the first workshop on Incorporating In Vitro Alternative Methods for Developmental Neurotoxicity (DNT) Testing into International Hazard and Risk Assessment Strategies, held in Ispra, Italy, on 19–21 April 2005. The workshop was hosted by the European Centre for the Validation of Alternative Methods (ECVAM) and jointly organized by ECVAM, the European Chemical Industry Council, and the Johns Hopkins University Center for Alternatives to Animal Testing. The primary aim of the workshop was to identify and catalog potential methods that could be used to assess how data from in vitro alternative methods could help to predict and identify DNT hazards. Working groups focused on two different aspects: a) details on the science available in the field of DNT, including discussions on the models available to capture the critical DNT mechanisms and processes, and b) policy and strategy aspects to assess the integration of alternative methods in a regulatory framework. This report summarizes these discussions and details the recommendations and priorities for future work. PMID:17589601

  15. Correction of surface aberration in strain scanning method with analyzer

    International Nuclear Information System (INIS)

    Shobu, Takahisa; Mizuki, Junichiro; Suzuki, Kenji; Akiniwa, Yoshiaki; Tanaka, Keisuke

    2006-01-01

    When a gauge volume sank below a specimen surface, the diffraction angle shifts. Thus, it is required to correct the surface aberration. For the annealed specimen of S45C, the shift in the diffraction angle was investigated using a strain scanning method with Ge (111) analyzer. This phenomenon was caused by the difference in the centroid between the geometric and the instrumental gauge volumes. This difference is explained by the following factors; 1) the change in the gauge volume by the divergence of the analyzer, 2) the X-ray penetration depth, 3) the gap of the centre line between the double receiving slits due to mis-setting the analyzer. As a result, the correcting method considered into these factors was proposed. For the shot-peened specimens of S45C, the diffraction angles were measured and corrected by our method. The distribution of the residual stress agreed with that obtained by the removal method. (author)

  16. Method and Apparatus for Creating a Topography at a Surface

    Science.gov (United States)

    Adams, David P.; Sinclair, Michael B.; Mayer, Thomas M.; Vasile, Michael J.; Sweatt, William C.

    2008-11-11

    Methods and apparatus whereby an optical interferometer is utilized to monitor and provide feedback control to an integrated energetic particle column, to create desired topographies, including the depth, shape and/or roughness of features, at a surface of a specimen. Energetic particle columns can direct energetic species including, ions, photons and/or neutral particles to a surface to create features having in-plane dimensions on the order of 1 micron, and a height or depth on the order of 1 nanometer. Energetic processes can include subtractive processes such as sputtering, ablation, focused ion beam milling and, additive processes, such as energetic beam induced chemical vapor deposition. The integration of interferometric methods with processing by energetic species offers the ability to create desired topographies at surfaces, including planar and curved shapes.

  17. Multi-phase-field method for surface tension induced elasticity

    Science.gov (United States)

    Schiedung, Raphael; Steinbach, Ingo; Varnik, Fathollah

    2018-01-01

    A method, based on the multi-phase-field framework, is proposed that adequately accounts for the effects of a coupling between surface free energy and elastic deformation in solids. The method is validated via a number of analytically solvable problems. In addition to stress states at mechanical equilibrium in complex geometries, the underlying multi-phase-field framework naturally allows us to account for the influence of surface energy induced stresses on phase transformation kinetics. This issue, which is of fundamental importance on the nanoscale, is demonstrated in the limit of fast diffusion for a solid sphere, which melts due to the well-known Gibbs-Thompson effect. This melting process is slowed down when coupled to surface energy induced elastic deformation.

  18. Temperature sensitive surfaces and methods of making same

    Science.gov (United States)

    Liang, Liang [Richland, WA; Rieke, Peter C [Pasco, WA; Alford, Kentin L [Pasco, WA

    2002-09-10

    Poly-n-isopropylacrylamide surface coatings demonstrate the useful property of being able to switch charateristics depending upon temperature. More specifically, these coatings switch from being hydrophilic at low temperature to hydrophobic at high temperature. Research has been conducted for many years to better characterize and control the properties of temperature sensitive coatings. The present invention provides novel temperature sensitive coatings on articles and novel methods of making temperature sensitive coatings that are disposed on the surfaces of various articles. These novel coatings contain the reaction products of n-isopropylacrylamide and are characterized by their properties such as advancing contact angles. Numerous other characteristics such as coating thickness, surface roughness, and hydrophilic-to-hydrophobic transition temperatures are also described. The present invention includes articles having temperature-sensitve coatings with improved properties as well as improved methods for forming temperature sensitive coatings.

  19. Localized surface plasmon resonance mercury detection system and methods

    Science.gov (United States)

    James, Jay; Lucas, Donald; Crosby, Jeffrey Scott; Koshland, Catherine P.

    2016-03-22

    A mercury detection system that includes a flow cell having a mercury sensor, a light source and a light detector is provided. The mercury sensor includes a transparent substrate and a submonolayer of mercury absorbing nanoparticles, e.g., gold nanoparticles, on a surface of the substrate. Methods of determining whether mercury is present in a sample using the mercury sensors are also provided. The subject mercury detection systems and methods find use in a variety of different applications, including mercury detecting applications.

  20. Method and apparatus for aligning laser reflective surfaces

    International Nuclear Information System (INIS)

    Caruolo, A.B.; Davis, J.W.; Walch, A.P.

    1975-01-01

    Methods and apparatus used in the alignment of high power laser systems to obtain optimum performance are disclosed. An external source of visible radiation provides an alignment beam which is reflected along the axis of a resonator. Reflecting surfaces of the resonator are aligned with respect to the axis located by the visible beam

  1. An alternative safer and cost effective surface sterilization method for ...

    African Journals Online (AJOL)

    Regardless of its serious health effect, mercury chloride is frequently utilized for surface sterilization to mitigate microbial contamination in sugarcane tissue culture. The current study aimed at finding an alternative safer and cost effective sterilization method to substitute mercury chloride. In the study, sugarcane shoot tip ...

  2. Response surface method to optimize the low cost medium for ...

    African Journals Online (AJOL)

    A protease producing Bacillus sp. GA CAS10 was isolated from ascidian Phallusia arabica, Tuticorin, Southeast coast of India. Response surface methodology was employed for the optimization of different nutritional and physical factors for the production of protease. Plackett-Burman method was applied to identify ...

  3. Surface sterilization method for reducing microbial contamination of ...

    African Journals Online (AJOL)

    An effective disinfection method for strawberry (Fragaria x ananassa Duch.) cv. Senga Sengana micropropagation using runner tips and nodal segments as explants was developed. The explants were surface sterilized with different sterilants for different durations. The present studies on the effect of different regimes of ...

  4. Assessment methods of injection moulded nano-patterned surfaces

    DEFF Research Database (Denmark)

    Menotti, S.; Bisacco, G.; Hansen, H. N.

    2014-01-01

    algorithm for feature recognition. To compare the methods, the mould insert and a number of replicated nano-patterned surfaces, injection moulded with an induction heating aid, were measured on nominally identical locations by means of an atomic force microscope mounted on a manual CMM....

  5. An alternative safer and cost effective surface sterilization method for ...

    African Journals Online (AJOL)

    user

    2013-10-30

    Oct 30, 2013 ... Regardless of its serious health effect, mercury chloride is frequently utilized for surface sterilization to mitigate microbial contamination in sugarcane tissue culture. The current study aimed at finding an alternative safer and cost effective sterilization method to substitute mercury chloride. In the study,.

  6. Comparison of surface sampling methods for virus recovery from fomites.

    Science.gov (United States)

    Julian, Timothy R; Tamayo, Francisco J; Leckie, James O; Boehm, Alexandria B

    2011-10-01

    The role of fomites in infectious disease transmission relative to other exposure routes is difficult to discern due, in part, to the lack of information on the level and distribution of virus contamination on surfaces. Comparisons of studies intending to fill this gap are difficult because multiple different sampling methods are employed and authors rarely report their method's lower limit of detection. In the present study, we compare a subset of sampling methods identified from a literature review to demonstrate that sampling method significantly influences study outcomes. We then compare a subset of methods identified from the review to determine the most efficient methods for recovering virus from surfaces in a laboratory trial using MS2 bacteriophage as a model virus. Recoveries of infective MS2 and MS2 RNA are determined using both a plaque assay and quantitative reverse transcription-PCR, respectively. We conclude that the method that most effectively recovers virus from nonporous fomites uses polyester-tipped swabs prewetted in either one-quarter-strength Ringer's solution or saline solution. This method recovers a median fraction for infective MS2 of 0.40 and for MS2 RNA of 0.07. Use of the proposed method for virus recovery in future fomite sampling studies would provide opportunities to compare findings across multiple studies.

  7. Surface zwitterionization: Effective method for preventing oral bacterial biofilm formation on hydroxyapatite surfaces

    Science.gov (United States)

    Lee, Myoungjin; Kim, Heejin; Seo, Jiae; Kang, Minji; Kang, Sunah; Jang, Joomyung; Lee, Yan; Seo, Ji-Hun

    2018-01-01

    In this study, we conducted surface zwitterionization of hydroxyapatite (HA) surfaces by immersing them in the zwitterionic polymer solutions to provide anti-bacterial properties to the HA surface. Three different monomers containing various zwitterionic groups, i.e., phosphorylcholine (PC), sulfobetaine (SB), and carboxybetaine (CB), were copolymerized with the methacrylic monomer containing a Ca2+-binding moiety, using the free radical polymerization method. As a control, functionalization of the copolymer containing the Ca2+-binding moiety was synthesized using a hydroxy group. The stable immobilization of the zwitterionic functional groups was confirmed by water contact angle analysis and X-ray photoelectron spectroscopy (XPS) measurement conducted after the sonication process. The zwitterionized HA surface showed significantly decreased protein adsorption, whereas the hydroxyl group-coated HA surface showed limited efficacy. The anti-bacterial adhesion property was confirmed by conducting Streptococcus mutans (S. mutans) adhesion tests for 6 h and 24 h. When furanone C-30, a representative anti-quorum sensing molecule for S. mutans, was used, only a small amount of bacteria adhered after 6 h and the population did not increase after 24 h. In contrast, zwitterionized HA surfaces showed almost no bacterial adhesion after 6 h and the effect was retained for 24 h, resulting in the lowest level of oral bacterial adhesion. These results confirm that surface zwitterionization is a promising method to effectively prevent oral bacterial adhesion on HA-based materials.

  8. A novel test method for quantifying surface tack of polypropylene compound surfaces

    Directory of Open Access Journals (Sweden)

    2011-11-01

    Full Text Available While adhesiveness is required for polymer surfaces in special applications, tacky surfaces are generally undesirable in many applications like automotive interior parts. The tackiness of polymer surface results from a combination of composition and additivation, and it can change significantly in natural or accelerated ageing. Since there is no established, uniform method to characterize surface tack, the major focus of the present work was on the development of an objective quantification method. A setup having a soft die tip attached to a standard tensile tester was developed aiming for correlation to the human sense of touch. Three different model thermoplastic polyolefin (TPO compound formulations based on a high-impact isotactic polypropylene (iPP composition with varying amounts and types of anti-scratch additives were used for these investigations. As the surface tack phenomenon is related to ageing and weathering, the material’s examination was also performed after various intervals of weathering. The developed method allows a fast assessment of the effect of polymer composition variations and different additive formulations on surface tack and gives identical rankings as the standardized haptic panel.

  9. Advances in calibration methods for micro- and nanoscale surfaces

    Science.gov (United States)

    Leach, R. K.; Giusca, C. L.; Coupland, J. M.

    2012-04-01

    Optical surface topography measuring instrument manufacturers often quote accuracies of the order of nanometres and claim that the instruments can reliably measure a range of surfaces with structures on the micro- to nanoscale. However, for many years there has been debate about the interpretation of the data from optical surface topography measuring instruments. Optical artefacts in the output data and a lack of a calibration infrastructure mean that it can be difficult to get optical instruments to agree with contact stylus instruments. In this paper, the current situation with areal surface topography measurements is discussed along with the ISO specification standards that are in draft form. An infrastructure is discussed whereby the ISO-defined metrological characteristics of optical instruments can be determined, but these characteristics do not allow the instrument to measure complex surfaces. Current research into methods for determining the transfer function of optical instruments is reviewed, which will allow the calibration of optical instruments to measure complex surfaces, at least in the case of weak scattering. The ability of some optical instruments to measure outside the spatial bandwidth limitation of the numerical aperture is presented and some general outlook for future work given.

  10. Optical triangulation method for height measurements on water surfaces

    Science.gov (United States)

    Maas, Hans-Gerd; Hentschel, Bernd; Schreiber, Frank

    2003-01-01

    Optical triangulation methods based on a laser light sheet and a camera are frequently used as a surface measurement technique in a wide range of applications. They allow for the fast accurate determination of height profiles, based on relatively simple hardware and software configurations. Moreover, they can be implemented very efficiently and are especially suited for measurements on moving objects such as products on an assembly line. The study presented in the paper describes the adaptation of laser light sheet optical triangulation techniques to the task of water level profile measurements in hydromechanics experimental facilities. The properties of water surfaces necessitate several modifications of optical triangulation techniques to make them applicable: The mirror-like reflection properties of water surfaces form a contradiction to the assumption of diffuse reflection, on which standard light sheet triangulation techniques are based; this problem can be circumvented by using a diffuse reflecting projection plane to capture the mirror-like reflection of the laser line from the water surface. Due to the angle of incidence law, however, water surface tilts caused by waves will usually cause a strong degradation of the quality of the results when using reflected light; this effect can largely be compensated by processing max-store images derived from short image sequences rather than single images. These extensions of optical triangulation turned out to be crucial for the applicability of the method on water surfaces. Besides the theoretical concept and a sensitivity analysis of the method, a system configuration is outlined, and the results of a number of practical experiments are shown and discussed.

  11. Surface Protonation at the Rutile (110) Interface: Explicit Incorporation of Solvation Structure within the Refined MUSIC Model Framework

    International Nuclear Information System (INIS)

    Machesky, Michael L.; Predota, M.; Wesolowski, David J.

    2008-01-01

    The detailed solvation structure at the (110) surface of rutile (α-TiO 2 ) in contact with bulk liquid water has been obtained primarily from experimentally verified classical molecular dynamics (CMD) simulations of the ab initio-optimized surface in contact with SPC/E water. The results are used to explicitly quantify H-bonding interactions, which are then used within the refined MUSIC model framework to predict surface oxygen protonation constants. Quantum mechanical molecular dynamics (QMD) simulations in the presence of freely dissociable water molecules produced H-bond distributions around deprotonated surface oxygens very similar to those obtained by CMD with nondissociable SPC/E water, thereby confirming that the less computationally intensive CMD simulations provide accurate H-bond information. Utilizing this H-bond information within the refined MUSIC model, along with manually adjusted Ti-O surface bond lengths that are nonetheless within 0.05 (angstrom) of those obtained from static density functional theory (DFT) calculations and measured in X-ray reflectivity experiments (as well as bulk crystal values), give surface protonation constants that result in a calculated zero net proton charge pH value (pHznpc) at 25 C that agrees quantitatively with the experimentally determined value (5.4 ± 0.2) for a specific rutile powder dominated by the (110) crystal face. Moreover, the predicted pH znpc values agree to within 0.1 pH unit with those measured at all temperatures between 10 and 250 C. A slightly smaller manual adjustment of the DFT-derived Ti-O surface bond lengths was sufficient to bring the predicted pH znpc value of the rutile (110) surface at 25 C into quantitative agreement with the experimental value (4.8 ± 0.3) obtained from a polished and annealed rutile (110) single crystal surface in contact with dilute sodium nitrate solutions using second harmonic generation (SHG) intensity measurements as a function of ionic strength. Additionally, the H

  12. Surface Protonation at the Rutile (110) Interface: Explicit Incorporation of Solvation Structure within the Refined MUSIC Model Framework

    Energy Technology Data Exchange (ETDEWEB)

    Machesky, Michael L. [Illinois State Water Survey, Champaign, IL; Predota, M. [University of South Bohemia, Czech Republic; Wesolowski, David J [ORNL

    2008-01-01

    The detailed solvation structure at the (110) surface of rutile ({alpha}-TiO{sub 2}) in contact with bulk liquid water has been obtained primarily from experimentally verified classical molecular dynamics (CMD) simulations of the ab initio-optimized surface in contact with SPC/E water. The results are used to explicitly quantify H-bonding interactions, which are then used within the refined MUSIC model framework to predict surface oxygen protonation constants. Quantum mechanical molecular dynamics (QMD) simulations in the presence of freely dissociable water molecules produced H-bond distributions around deprotonated surface oxygens very similar to those obtained by CMD with nondissociable SPC/E water, thereby confirming that the less computationally intensive CMD simulations provide accurate H-bond information. Utilizing this H-bond information within the refined MUSIC model, along with manually adjusted Ti-O surface bond lengths that are nonetheless within 0.05 {angstrom} of those obtained from static density functional theory (DFT) calculations and measured in X-ray reflectivity experiments (as well as bulk crystal values), give surface protonation constants that result in a calculated zero net proton charge pH value (pHznpc) at 25 C that agrees quantitatively with the experimentally determined value (5.4 {+-} 0.2) for a specific rutile powder dominated by the (110) crystal face. Moreover, the predicted pH{sub znpc} values agree to within 0.1 pH unit with those measured at all temperatures between 10 and 250 C. A slightly smaller manual adjustment of the DFT-derived Ti-O surface bond lengths was sufficient to bring the predicted pH{sub znpc} value of the rutile (110) surface at 25 C into quantitative agreement with the experimental value (4.8 {+-} 0.3) obtained from a polished and annealed rutile (110) single crystal surface in contact with dilute sodium nitrate solutions using second harmonic generation (SHG) intensity measurements as a function of ionic

  13. Method for Reduction of Silver Biocide Plating on Metal Surfaces

    Science.gov (United States)

    Steele, John; Nalette, Timothy; Beringer, Durwood

    2013-01-01

    Silver ions in aqueous solutions (0.05 to 1 ppm) are used for microbial control in water systems. The silver ions remain in solution when stored in plastic containers, but the concentration rapidly decreases to non-biocidal levels when stored in metal containers. The silver deposits onto the surface and is reduced to non-biocidal silver metal when it contacts less noble metal surfaces, including stainless steel, titanium, and nickel-based alloys. Five methods of treatment of contact metal surfaces to deter silver deposition and reduction are proposed: (1) High-temperature oxidation of the metal surface; (2) High-concentration silver solution pre-treatment; (3) Silver plating; (4) Teflon coat by vapor deposition (titanium only); and (5) A combination of methods (1) and (2), which proved to be the best method for the nickel-based alloy application. The mechanism associated with surface treatments (1), (2), and (5) is thought to be the development of a less active oxide layer that deters ionic silver deposition. Mechanism (3) is an attempt to develop an equilibrium ionic silver concentration via dissolution of metallic silver. Mechanism (4) provides a non-reactive barrier to deter ionic silver plating. Development testing has shown that ionic silver in aqueous solution was maintained at essentially the same level of addition (0.4 ppm) for up to 15 months with method (5) (a combination of methods (1) and (2)), before the test was discontinued for nickel-based alloys. Method (1) resulted in the maintenance of a biocidal level (approximately 0.05 ppm) for up to 10 months before that test was discontinued for nickel-based alloys. Methods (1) and (2) used separately were able to maintain ionic silver in aqueous solution at essentially the same level of addition (0.4 ppm) for up to 10 months before the test was discontinued for stainless steel alloys. Method (3) was only utilized for titanium alloys, and was successful at maintaining ionic silver in aqueous solution at

  14. Methods to study microbial adhesion on abiotic surfaces

    Directory of Open Access Journals (Sweden)

    Ana Meireles

    2015-09-01

    Full Text Available Microbial biofilms are a matrix of cells and exopolymeric substances attached to a wet and solid surface and are commonly associated to several problems, such as biofouling and corrosion in industries and infectious diseases in urinary catheters and prosthesis. However, these cells may have several benefits in distinct applications, such as wastewater treatment processes, microbial fuel cells for energy production and biosensors. As microbial adhesion is a key step on biofilm formation, it is very important to understand and characterize microbial adhesion to a surface. This study presents an overview of predictive and experimental methods used for the study of bacterial adhesion. Evaluation of surface physicochemical properties have a limited capacity in describing the complex adhesion process. Regarding the experimental methods, there is no standard method or platform available for the study of microbial adhesion and a wide variety of methods, such as colony forming units counting and microscopy techniques, can be applied for quantification and characterization of the adhesion process.

  15. Simulating condensation on microstructured surfaces using Lattice Boltzmann Method

    Science.gov (United States)

    Alexeev, Alexander; Vasyliv, Yaroslav

    2017-11-01

    We simulate a single component fluid condensing on 2D structured surfaces with different wettability. To simulate the two phase fluid, we use the athermal Lattice Boltzmann Method (LBM) driven by a pseudopotential force. The pseudopotential force results in a non-ideal equation of state (EOS) which permits liquid-vapor phase change. To account for thermal effects, the athermal LBM is coupled to a finite volume discretization of the temperature evolution equation obtained using a thermal energy rate balance for the specific internal energy. We use the developed model to probe the effect of surface structure and surface wettability on the condensation rate in order to identify microstructure topographies promoting condensation. Financial support is acknowledged from Kimberly-Clark.

  16. Facile stamp patterning method for superhydrophilic/superhydrophobic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, Sungnam, E-mail: blueden@postech.ac.kr; Hwang, Woonbong, E-mail: whwang@postech.ac.kr [Department of Mechanical Engineering, POSTECH, Pohang 680-749 (Korea, Republic of)

    2015-11-16

    Patterning techniques are essential to many research fields such as chemistry, biology, medicine, and micro-electromechanical systems. In this letter, we report a simple, fast, and low-cost superhydrophobic patterning method using a superhydrophilic template. The technique is based on the contact stamping of the surface during hydrophobic dip coating. Surface characteristics were measured using scanning electron microscopy and energy-dispersive X-ray spectroscopic analysis. The results showed that the hydrophilic template, which was contacted with the stamp, was not affected by the hydrophobic solution. The resolution study was conducted using a stripe shaped stamp. The patterned line was linearly proportional to the width of the stamp line with a constant narrowing effect. A surface with regions of four different types of wetting was fabricated to demonstrate the patterning performance.

  17. Scattering of surface waves modelled by the integral equation method

    Science.gov (United States)

    Lu, Laiyu; Maupin, Valerie; Zeng, Rongsheng; Ding, Zhifeng

    2008-09-01

    The integral equation method is used to model the propagation of surface waves in 3-D structures. The wavefield is represented by the Fredholm integral equation, and the scattered surface waves are calculated by solving the integral equation numerically. The integration of the Green's function elements is given analytically by treating the singularity of the Hankel function at R = 0, based on the proper expression of the Green's function and the addition theorem of the Hankel function. No far-field and Born approximation is made. We investigate the scattering of surface waves propagating in layered reference models imbedding a heterogeneity with different density, as well as Lamé constant contrasts, both in frequency and time domains, for incident plane waves and point sources.

  18. Response-Surface Methods in R, Using rsm

    Directory of Open Access Journals (Sweden)

    Russell V. Lenth

    2009-10-01

    Full Text Available This article describes the recent package rsm, which was designed to provide R support for standard response-surface methods. Functions are provided to generate central-composite and Box-Behnken designs. For analysis of the resulting data, the package provides for estimating the response surface, testing its lack of fit, displaying an ensemble of contour plots of the fitted surface, and doing follow-up analyses such as steepest ascent, canonical analysis, and ridge analysis. It also implements a coded-data structure to aid in this essential aspect of the methodology. The functions are designed in hopes of providing an intuitive and effective user interface. Potential exists for expanding the package in a variety of ways.

  19. Exploration on Kerf-angle and Surface Roughness in Abrasive Waterjet Machining using Response Surface Method

    Science.gov (United States)

    Babu, Munuswamy Naresh; Muthukrishnan, Nambi

    2017-05-01

    Abrasive waterjet machining is a mechanical based unconventional cutting process which uses a mixture of abrasives and pressurized water as an intermediate to cut the material. The present paper focuses in analyzing the effect process parameters like feed rate, water pressure, standoff distance and abrasive flow rate on the surface roughness and kerf-angle of AISI 1018 mild steel experimentally. The experiments were performed under Taguchi's L27 orthogonal array. Moreover, the optimal parameter that significantly reduces the surface roughness and kerf-angle were calculated through response surface method. The most dominating process parameter that affects the responses was calculated by the Analysis of variance. In addition, machined surfaces are further subjected to scanning electron microscope (SEM) and atomic force microscope (AFM) for detailed study on the texture developed.

  20. Method for Constructing Composite Response Surfaces by Combining Neural Networks with Polynominal Interpolation or Estimation Techniques

    Science.gov (United States)

    Rai, Man Mohan (Inventor); Madavan, Nateri K. (Inventor)

    2007-01-01

    A method and system for data modeling that incorporates the advantages of both traditional response surface methodology (RSM) and neural networks is disclosed. The invention partitions the parameters into a first set of s simple parameters, where observable data are expressible as low order polynomials, and c complex parameters that reflect more complicated variation of the observed data. Variation of the data with the simple parameters is modeled using polynomials; and variation of the data with the complex parameters at each vertex is analyzed using a neural network. Variations with the simple parameters and with the complex parameters are expressed using a first sequence of shape functions and a second sequence of neural network functions. The first and second sequences are multiplicatively combined to form a composite response surface, dependent upon the parameter values, that can be used to identify an accurate mode

  1. Resistance Monitoring of Four Insecticides and a Description of an Artificial Diet Incorporation Method for Chilo suppressalis (Lepidoptera: Crambidae).

    Science.gov (United States)

    Shuijin, Huang; Qiong, Chen; Wenjing, Qin; Yang, Sun; Houguo, Qin

    2017-12-05

    Chilo suppressalis (Walker; Lepidoptera: Crambidae) is one of the most damaging rice pests in China. Insecticides play a major role in its management. We describe how we monitored the resistance of C. suppressalis to four insecticides in seven field populations from Jiangxi, Hubei, and Hunan Provinces, China, in 2014-2016. The topical application method for resistance monitoring was suitable for triazophos, monosultap, and abamectin. The conventional rice seedling dipping method proved ineffective for testing chlorantraniliprole so the new artificial diet incorporation method was substituted. This new method provided more consistent results than the other methods, once baseline toxicity data had been established. All populations had moderate to high resistance to triazophos from 2014 to 2016. Monosultap resistance in two populations increased from low in 2014 to moderate in 2016 and the other five populations showed moderate to high-level resistance throughout. Abamectin resistance in three populations increased from sensitive or low in 2014 to moderate in 2015-2016, and the other populations had moderate to high levels of resistance. Resistance to chlorantraniliprole increased from sensitive or low in 2014 to moderate to high in 2016. These results suggested that resistance management strategies should be developed according to the needs of a specific location. It was suggested that, in these localities, organophosphate insecticides should be prohibited, the application of nereistoxin, macrolide antibiotic, and diamide insecticides should be limited, and other insecticides, including spinetoram and methoxyfenozide, that exhibited no resistance should be used rationally and in rotation to delay resistance development. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Applications of Response Surface-Based Methods to Noise Analysis in the Conceptual Design of Revolutionary Aircraft

    Science.gov (United States)

    Hill, Geoffrey A.; Olson, Erik D.

    2004-01-01

    Due to the growing problem of noise in today's air transportation system, there have arisen needs to incorporate noise considerations in the conceptual design of revolutionary aircraft. Through the use of response surfaces, complex noise models may be converted into polynomial equations for rapid and simplified evaluation. This conversion allows many of the commonly used response surface-based trade space exploration methods to be applied to noise analysis. This methodology is demonstrated using a noise model of a notional 300 passenger Blended-Wing-Body (BWB) transport. Response surfaces are created relating source noise levels of the BWB vehicle to its corresponding FAR-36 certification noise levels and the resulting trade space is explored. Methods demonstrated include: single point analysis, parametric study, an optimization technique for inverse analysis, sensitivity studies, and probabilistic analysis. Extended applications of response surface-based methods in noise analysis are also discussed.

  3. KaKs_Calculator 2.0: A Toolkit Incorporating Gamma-Series Methods and Sliding Window Strategies

    KAUST Repository

    Wang, Dapeng

    2010-05-05

    We present an integrated stand-alone software package named KaKs_Calculator 2.0 as an updated version. It incorporates 17 methods for the calculation of nonsynonymous and synonymous substitution rates; among them, we added our modified versions of several widely used methods as the gamma series including γ-NG, γ-LWL, γ-MLWL, γ-LPB, γ-MLPB, γ-YN and γ-MYN, which have been demonstrated to perform better under certain conditions than their original forms and are not implemented in the previous version. The package is readily used for the identification of positively selected sites based on a sliding window across the sequences of interests in 5\\' to 3\\' direction of protein-coding sequences, and have improved the overall performance on sequence analysis for evolution studies. A toolbox, including C++ and Java source code and executable files on both Windows and Linux platforms together with a user instruction, is downloadable from the website for academic purpose at https://sourceforge.net/projects/kakscalculator2/.

  4. Theoretical studies of potential energy surfaces and computational methods

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, R. [Argonne National Laboratory, IL (United States)

    1993-12-01

    This project involves the development, implementation, and application of theoretical methods for the calculation and characterization of potential energy surfaces involving molecular species that occur in hydrocarbon combustion. These potential energy surfaces require an accurate and balanced treatment of reactants, intermediates, and products. This difficult challenge is met with general multiconfiguration self-consistent-field (MCSCF) and multireference single- and double-excitation configuration interaction (MRSDCI) methods. In contrast to the more common single-reference electronic structure methods, this approach is capable of describing accurately molecular systems that are highly distorted away from their equilibrium geometries, including reactant, fragment, and transition-state geometries, and of describing regions of the potential surface that are associated with electronic wave functions of widely varying nature. The MCSCF reference wave functions are designed to be sufficiently flexible to describe qualitatively the changes in the electronic structure over the broad range of geometries of interest. The necessary mixing of ionic, covalent, and Rydberg contributions, along with the appropriate treatment of the different electron-spin components (e.g. closed shell, high-spin open-shell, low-spin open shell, radical, diradical, etc.) of the wave functions, are treated correctly at this level. Further treatment of electron correlation effects is included using large scale multireference CI wave functions, particularly including the single and double excitations relative to the MCSCF reference space. This leads to the most flexible and accurate large-scale MRSDCI wave functions that have been used to date in global PES studies.

  5. Comparison of optical methods for surface roughness characterization

    DEFF Research Database (Denmark)

    Feidenhans'l, Nikolaj Agentoft; Hansen, Poul Erik; Pilny, Lukas

    2015-01-01

    We report a study of the correlation between three optical methods for characterizing surface roughness: a laboratory scatterometer measuring the bi-directional reflection distribution function (BRDF instrument), a simple commercial scatterometer (rBRDF instrument), and a confocal optical profiler...... of the scattering angle distribution (Aq). The twenty-two investigated samples were manufactured with several methods in order to obtain a suitable diversity of roughness patterns.Our study shows a one-to-one correlation of both the Rq and the Rdq roughness values when obtained with the BRDF and the confocal...

  6. Vibration analysis of bonded double-FGM viscoelastic nanoplate systems based on a modified strain gradient theory incorporating surface effects

    Science.gov (United States)

    Jamalpoor, Ali; Kiani, Ali

    2017-03-01

    On the basis of the modified strain gradient theory, the present paper deals with the theoretical analysis of the free vibration of coupled double-FGM viscoelastic nanoplates by Kelvin-Voigt visco-Pasternak medium. To establish static equilibrium of atoms on the each nanoplate surface, the effects of the surface layers are considered. The properties of material in the thickness direction vary according to the power low distribution. Kirchhoff plate assumption and Hamilton's variational principle are employed to achieve the partial differential equations for three different cases of vibration (out-of-phase, in-phase, and one nanoplate of the system being stationary) and corresponding boundary conditions. Navier's approach which satisfies the simply supported boundary conditions applied to analytically investigate the size effect on the natural frequencies of double-FGM viscoelastic nanoplate systems. Numerical studies are carried out to illustrate the influence of viscoelastic damping structural of the nanoplates, damping coefficient of the visco-Pasternak medium, independent length scale parameter, aspect ratio, surface properties, and other factors on the frequency behavior system. Some numerical results of this research illustrate that the frequencies may increase or decrease with respect to the sign of the surface properties of FGMs.

  7. Delta self-consistent field method to obtain potential energy surfaces of excited molecules on surfaces

    DEFF Research Database (Denmark)

    Gavnholt, Jeppe; Olsen, Thomas; Engelund, Mads

    2008-01-01

    is a density-functional method closely resembling standard density-functional theory (DFT), the only difference being that in Delta SCF one or more electrons are placed in higher lying Kohn-Sham orbitals instead of placing all electrons in the lowest possible orbitals as one does when calculating the ground......-photoemission spectroscopy measurements. This comparison shows that the modified Delta SCF method gives results in close agreement with experiment, significantly closer than the comparable methods. For N2 adsorbed on ruthenium (0001) we map out a two-dimensional part of the potential energy surfaces in the ground state...

  8. TWO METHODS FOR REMOTE ESTIMATION OF COMPLETE URBAN SURFACE TEMPERATURE

    Directory of Open Access Journals (Sweden)

    L. Jiang

    2017-09-01

    Full Text Available Complete urban surface temperature (TC is a key parameter for evaluating the energy exchange between the urban surface and atmosphere. At the present stage, the estimation of TC still needs detailed 3D structure information of the urban surface, however, it is often difficult to obtain the geometric structure and composition of the corresponding temperature of urban surface, so that there is still lack of concise and efficient method for estimating the TC by remote sensing. Based on the four typical urban surface scale models, combined with the Envi-met model, thermal radiant directionality forward modeling and kernel model, we analyzed a complete day and night cycle hourly component temperature and radiation temperature in each direction of two seasons of summer and winter, and calculated hemispherical integral temperature and TC. The conclusion is obtained by examining the relationship of directional radiation temperature, hemispherical integral temperature and TC: (1 There is an optimal angle of radiation temperature approaching the TC in a single observation direction when viewing zenith angle is 45–60°, the viewing azimuth near the vertical surface of the sun main plane, the average absolute difference is about 1.1 K in the daytime. (2 There are several (3–5 times directional temperatures of different view angle, under the situation of using the thermal radiation directionality kernel model can more accurately calculate the hemispherical integral temperature close to TC, the mean absolute error is about 1.0 K in the daytime. This study proposed simple and effective strategies for estimating TC by remote sensing, which are expected to improve the quantitative level of remote sensing of urban thermal environment.

  9. Two Methods for Remote Estimation of Complete Urban Surface Temperature

    Science.gov (United States)

    Jiang, L.; Zhan, W.; Zou, Z.

    2017-09-01

    Complete urban surface temperature (TC) is a key parameter for evaluating the energy exchange between the urban surface and atmosphere. At the present stage, the estimation of TC still needs detailed 3D structure information of the urban surface, however, it is often difficult to obtain the geometric structure and composition of the corresponding temperature of urban surface, so that there is still lack of concise and efficient method for estimating the TC by remote sensing. Based on the four typical urban surface scale models, combined with the Envi-met model, thermal radiant directionality forward modeling and kernel model, we analyzed a complete day and night cycle hourly component temperature and radiation temperature in each direction of two seasons of summer and winter, and calculated hemispherical integral temperature and TC. The conclusion is obtained by examining the relationship of directional radiation temperature, hemispherical integral temperature and TC: (1) There is an optimal angle of radiation temperature approaching the TC in a single observation direction when viewing zenith angle is 45-60°, the viewing azimuth near the vertical surface of the sun main plane, the average absolute difference is about 1.1 K in the daytime. (2) There are several (3-5 times) directional temperatures of different view angle, under the situation of using the thermal radiation directionality kernel model can more accurately calculate the hemispherical integral temperature close to TC, the mean absolute error is about 1.0 K in the daytime. This study proposed simple and effective strategies for estimating TC by remote sensing, which are expected to improve the quantitative level of remote sensing of urban thermal environment.

  10. A Novel Method for Incorporation of Micron-Sized SiC Particles into Molten Pure Aluminum Utilizing a Co Coating

    Science.gov (United States)

    Mohammadpour, M.; Khosroshahi, R. Azari; Mousavian, R. Taherzadeh; Brabazon, D.

    2015-02-01

    Ceramic particles typically do not have sufficiently high wettability by molten metal for effective bonding during metal matrix composite fabrication. In this study, a novel method has been used to overcome this drawback. Micron-sized SiC particles were coated by a cobalt metallic layer using an electroless deposition method. A layer of cobalt on the SiC particles was produced prior to incorporation in molten pure aluminum in order to improve the injected particle bonding with the matrix. For comparison, magnesium was added to the melt in separate experiments as a wetting agent to assess which method was more effective for particle incorporation. It was found that both of these methods were more effective as regard ceramic particulate incorporation compared with samples produced with as-received SiC particles injected into the pure aluminum matrix. SEM images indicated that cobalt coating of the particles was more effective than magnesium for incorporation of fine SiC particles (below 30 µm), while totally the incorporation percentage of the particles was higher for a sample in which Mg was added as a wetting agent. In addition, microhardness tests revealed that the cobalt coating leads to the fabrication of a harder composite due to increased amount of ceramic incorporation, ceramic-matrix bonding, and possibly also to formation of Al-Co intermetallic phases.

  11. Incorporation of surface plasmon resonance with novel valinomycin doped chitosan-graphene oxide thin film for sensing potassium ion

    Science.gov (United States)

    Zainudin, Afiq Azri; Fen, Yap Wing; Yusof, Nor Azah; Al-Rekabi, Sura Hmoud; Mahdi, Mohd Adzir; Omar, Nur Alia Sheh

    2018-02-01

    In this study, the combination of novel valinomycin doped chitosan-graphene oxide (C-GO-V) thin film and surface plasmon resonance (SPR) system for potassium ion (K+) detection has been developed. The novel C-GO-V thin film was deposited on the gold surface using spin coating technique. The system was used to monitor SPR signal for K+ in solution with and without C-GO-V thin film. The K+ can be detected by measuring the SPR signal when C-GO-V thin film is exposed to K+ in solution. The sensor produces a linear response for K+ ion up to 100 ppm with sensitivity and detection limit of 0.00948° ppm- 1 and 0.001 ppm, respectively. These results indicate that the C-GO-V film is high potential as a sensor element for K+ that has been proved by the SPR measurement.

  12. Superhydrophobic photocatalytic surfaces through direct incorporation of titania nanoparticles into a polymer matrix by aerosol assisted chemical vapor deposition.

    Science.gov (United States)

    Crick, Colin R; Bear, Joseph C; Kafizas, Andreas; Parkin, Ivan P

    2012-07-10

    A new class of superhydrophobic photocatalytic surfaces that are self-cleaning through light-induced photodegradation and the Lotus effect are presented. The films are formed in a single-step aerosol-assisted chemical vapor deposition (AACVD) process. The films are durable and show no degradation on continuous exposure to UV-C radiation. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Non thermal plasma surface cleaner and method of use

    KAUST Repository

    Neophytou, Marios

    2017-09-14

    Described herein are plasma generation devices and methods of use of the devices. The devices can be used for the cleaning of various surfaces and/or for inhibiting or preventing the accumulation of particulates, such as dust, or moisture on various surfaces. The devices can be used to remove dust and other particulate contaminants from solar panels and windows, or to avoid or minimize condensation on various surfaces. In an embodiment a plasma generation device is provided. The plasma generation device can comprise: a pair of electrodes (1,2) positioned in association with a surface of a dielectric substrate (3). The pair of electrodes (1,2) can comprise a first electrode (1) and a second electrode (2). The first electrode and second electrode can be of different sizes, one of the electrodes being smaller than the other of the electrodes. The first electrode and second electrode can be separated by a distance and electrically connected to a voltage source (4,5).

  14. Physical and chemical characterization methods of surfaces and interfaces; Methodes de caracterisation physico-chimique des surfaces et des interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Barthes-Labrousse, M.G. [Centre d`Etudes de Chimie Metallurgique, 94 - Vitry-sur-Seine (France)

    1997-12-31

    The main physical and chemical characterization techniques of surfaces and interfaces are presented. There are: Auger electron spectroscopy, photoelectron spectroscopies (XPS and UPS), secondary ions mass spectroscopy (SIMS), infrared and Raman spectroscopies, electron energy loss spectroscopy (EELS and HREELS) and atomic force microscopy (AFM). For each method is given the theoretical principle, the apparatus and the main uses of the techniques. (O.M.) 27 refs.

  15. Surface charge method for molecular surfaces with curved areal elements I. Spherical triangles

    Science.gov (United States)

    Yu, Yi-Kuo

    2018-03-01

    Parametrizing a curved surface with flat triangles in electrostatics problems creates a diverging electric field. One way to avoid this is to have curved areal elements. However, charge density integration over curved patches appears difficult. This paper, dealing with spherical triangles, is the first in a series aiming to solve this problem. Here, we lay the ground work for employing curved patches for applying the surface charge method to electrostatics. We show analytically how one may control the accuracy by expanding in powers of the the arc length (multiplied by the curvature). To accommodate not extremely small curved areal elements, we have provided enough details to include higher order corrections that are needed for better accuracy when slightly larger surface elements are used.

  16. Hydrogen dissociation and incorporation on Mg{sub 17}Al{sub 12}(100) surface: A density functional theory study

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Hua [Guangxi Key Laboratory for Relativistic Astrophysics, Guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related Technology, College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China); Zhou, Zhiyan; Zhang, Ziyan [Guangxi Key Laboratory for Relativistic Astrophysics, Guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related Technology, College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Zhou, Wenzheng; Li, Guangxu [Guangxi Key Laboratory for Relativistic Astrophysics, Guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related Technology, College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China); Guo, Jin, E-mail: guojin@gxu.edu.cn [Guangxi Key Laboratory for Relativistic Astrophysics, Guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related Technology, College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China)

    2017-02-28

    Highlights: • Hydrogen adsorption, dissociation, and penetration on (in) Mg{sub 17}Al{sub 12} (100) surface are studied. • Hydrogen molecules are dissociated on the surface with barrier of 0.63 eV. • The maximum barrier energy for atomic hydrogen penetration into the subsurface is ∼0.7 eV. • The hybridization between the s orbital of H and the s orbitals of Mg is major. - Abstract: Hydrogen adsorption, dissociation, and penetration on (in) Mg{sub 17}Al{sub 12} (100) surface are studied extensively by DFT total-energy calculations. The adsorption geometries, dissociation barriers, various diffusion pathways, penetrative processes, and electronic structures were investigated. Results show that the atomic and molecular hydrogen forms prefer to be adsorbed on the Mg3-Mg3 bridge sites (C sites). Hydrogen molecules are dissociated on the surface with the minimum barrier energy of 0.63 eV. There are two stages in the process of hydrogen incorporation, which are hydrogen diffusion on the surface and the penetration from the surface into the subsurface. Two possible pathways of atomic hydrogen penetration from surface into subsurface are found. The calculations of electronic structures show that the hybridization between the s orbital of H and the s orbitals of Mg is major. The Mg-Mg bond on the outmost surface is shortened from 4.48 Å to 3.30 Å after the hydrogen adsorption on C sites, showing the strong interaction between Mg and H atoms.

  17. New method to design stellarator coils without the winding surface

    Science.gov (United States)

    Zhu, Caoxiang; Hudson, Stuart R.; Song, Yuntao; Wan, Yuanxi

    2018-01-01

    Finding an easy-to-build coils set has been a critical issue for stellarator design for decades. Conventional approaches assume a toroidal ‘winding’ surface, but a poorly chosen winding surface can unnecessarily constrain the coil optimization algorithm, This article presents a new method to design coils for stellarators. Each discrete coil is represented as an arbitrary, closed, one-dimensional curve embedded in three-dimensional space. A target function to be minimized that includes both physical requirements and engineering constraints is constructed. The derivatives of the target function with respect to the parameters describing the coil geometries and currents are calculated analytically. A numerical code, named flexible optimized coils using space curves (FOCUS), has been developed. Applications to a simple stellarator configuration, W7-X and LHD vacuum fields are presented.

  18. A new method for patterning azopolymer thin film surfaces

    Science.gov (United States)

    Sorkhabi, Sh. Golghasemi; Barille, R.; Ahmadi-Kandjani, S.; Zielinska, S.; Ortyl, E.

    2017-04-01

    We present a simple bottom-up approach via an incoherent unpolarized illumination and the choice of a solvent-droplet-induced-dewetting method to photoinduce nano doughnuts on the surface of azopolymer thin films. We demonstrate that doughnut-shaped nanostructures can be formed and tailored with a wide range of typical sizes, thus providing a rich field of applications using surface photo-patterning. Furthermore, due to the presence of highly photoactive azobenzene derivative in the material, illumination of these nanostructures by a polarized laser light shows the possibility of a further growth and reshaping opening the way for fundamental studies of size-dependent scaling laws of optical properties and possible fabrication of nano-reactor or nano-trap patterns.

  19. Economic method for helical gear flank surface characterisation

    Science.gov (United States)

    Koulin, G.; Reavie, T.; Frazer, R. C.; Shaw, B. A.

    2018-03-01

    Typically the quality of a gear pair is assessed based on simplified geometric tolerances which do not always correlate with functional performance. In order to identify and quantify functional performance based parameters, further development of the gear measurement approach is required. Methodology for interpolation of the full active helical gear flank surface, from sparse line measurements, is presented. The method seeks to identify the minimum number of line measurements required to sufficiently characterise an active gear flank. In the form ground gear example presented, a single helix and three profile line measurements was considered to be acceptable. The resulting surfaces can be used to simulate the meshing engagement of a gear pair and therefore provide insight into functional performance based parameters. Therefore the assessment of the quality can be based on the predicted performance in the context of an application.

  20. Surface Protonation at the Rutile (110) Interface: Explicit Incorporation of Solvation Structure within the Refined MUSIC Model Framework

    Czech Academy of Sciences Publication Activity Database

    Machesky, M.L.; Předota, Milan; Wesolowski, D.J.; Vlček, Lukáš; Cummings, P. T.; Rosenqvist, J.; Ridley, M.K.; Kubicki, J.D.; Bandura, A.V.; Kumar, N.; Sofo, J.O.

    2008-01-01

    Roč. 24, č. 21 (2008), s. 12331-12339 ISSN 0743-7463 R&D Projects: GA ČR GA203/08/0094; GA AV ČR 1ET400720507 Grant - others:M.K.R.(US) EAR/0124001; M.L.M(US) DE/AC05/00OR22725 Institutional research plan: CEZ:AV0Z40720504 Keywords : solid-liquid interface * surface * simulation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.097, year: 2008

  1. An experimental method for making spectral emittance and surface temperature measurements of opaque surfaces

    International Nuclear Information System (INIS)

    Moore, Travis J.; Jones, Matthew R.; Tree, Dale R.; Daniel Maynes, R.; Baxter, Larry L.

    2011-01-01

    An experimental procedure has been developed to make spectral emittance and temperature measurements. The spectral emittance of an object is calculated using measurements of the spectral emissive power and of the surface temperature of the object obtained using a Fourier transform infrared (FTIR) spectrometer. A calibration procedure is described in detail which accounts for the temperature dependence of the detector. The methods used to extract the spectral emissive power and surface temperature from measured infrared spectra were validated using a blackbody radiator at known temperatures. The average error in the measured spectral emittance was 2.1% and the average difference between the temperature inferred from the recorded spectra and the temperature indicated on the blackbody radiator was 1.2%. The method was used to measure the spectral emittance of oxidized copper at various temperatures.

  2. Incorporating High-Frequency Physiologic Data Using Computational Dictionary Learning Improves Prediction of Delayed Cerebral Ischemia Compared to Existing Methods

    Directory of Open Access Journals (Sweden)

    Murad Megjhani

    2018-03-01

    Full Text Available PurposeAccurate prediction of delayed cerebral ischemia (DCI after subarachnoid hemorrhage (SAH can be critical for planning interventions to prevent poor neurological outcome. This paper presents a model using convolution dictionary learning to extract features from physiological data available from bedside monitors. We develop and validate a prediction model for DCI after SAH, demonstrating improved precision over standard methods alone.Methods488 consecutive SAH admissions from 2006 to 2014 to a tertiary care hospital were included. Models were trained on 80%, while 20% were set aside for validation testing. Modified Fisher Scale was considered the standard grading scale in clinical use; baseline features also analyzed included age, sex, Hunt–Hess, and Glasgow Coma Scales. An unsupervised approach using convolution dictionary learning was used to extract features from physiological time series (systolic blood pressure and diastolic blood pressure, heart rate, respiratory rate, and oxygen saturation. Classifiers (partial least squares and linear and kernel support vector machines were trained on feature subsets of the derivation dataset. Models were applied to the validation dataset.ResultsThe performances of the best classifiers on the validation dataset are reported by feature subset. Standard grading scale (mFS: AUC 0.54. Combined demographics and grading scales (baseline features: AUC 0.63. Kernel derived physiologic features: AUC 0.66. Combined baseline and physiologic features with redundant feature reduction: AUC 0.71 on derivation dataset and 0.78 on validation dataset.ConclusionCurrent DCI prediction tools rely on admission imaging and are advantageously simple to employ. However, using an agnostic and computationally inexpensive learning approach for high-frequency physiologic time series data, we demonstrated that we could incorporate individual physiologic data to achieve higher classification accuracy.

  3. Roman sophisticated surface modification methods to manufacture silver counterfeited coins

    Science.gov (United States)

    Ingo, G. M.; Riccucci, C.; Faraldi, F.; Pascucci, M.; Messina, E.; Fierro, G.; Di Carlo, G.

    2017-11-01

    By means of the combined use of X-ray photoelectron spectroscopy (XPS), optical microscopy (OM) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS) the surface and subsurface chemical and metallurgical features of silver counterfeited Roman Republican coins are investigated to decipher some aspects of the manufacturing methods and to evaluate the technological ability of the Roman metallurgists to produce thin silver coatings. The results demonstrate that over 2000 ago important advances in the technology of thin layer deposition on metal substrates were attained by Romans. The ancient metallurgists produced counterfeited coins by combining sophisticated micro-plating methods and tailored surface chemical modification based on the mercury-silvering process. The results reveal that Romans were able systematically to chemically and metallurgically manipulate alloys at a micro scale to produce adherent precious metal layers with a uniform thickness up to few micrometers. The results converge to reveal that the production of forgeries was aimed firstly to save expensive metals as much as possible allowing profitable large-scale production at a lower cost. The driving forces could have been a lack of precious metals, an unexpected need to circulate coins for trade and/or a combinations of social, political and economic factors that requested a change in money supply. Finally, some information on corrosion products have been achieved useful to select materials and methods for the conservation of these important witnesses of technology and economy.

  4. Improved detection of highly energetic materials traces on surfaces by standoff laser-induced thermal emission incorporating neural networks

    Science.gov (United States)

    Figueroa-Navedo, Amanda; Galán-Freyle, Nataly Y.; Pacheco-Londoño, Leonardo C.; Hernández-Rivera, Samuel P.

    2013-05-01

    Terrorists conceal highly energetic materials (HEM) as Improvised Explosive Devices (IED) in various types of materials such as PVC, wood, Teflon, aluminum, acrylic, carton and rubber to disguise them from detection equipment used by military and security agency personnel. Infrared emissions (IREs) of substrates, with and without HEM, were measured to generate models for detection and discrimination. Multivariable analysis techniques such as principal component analysis (PCA), soft independent modeling by class analogy (SIMCA), partial least squares-discriminant analysis (PLS-DA), support vector machine (SVM) and neural networks (NN) were employed to generate models, in which the emission of IR light from heated samples was stimulated using a CO2 laser giving rise to laser induced thermal emission (LITE) of HEMs. Traces of a specific target threat chemical explosive: PETN in surface concentrations of 10 to 300 ug/cm2 were studied on the surfaces mentioned. Custom built experimental setup used a CO2 laser as a heating source positioned with a telescope, where a minimal loss in reflective optics was reported, for the Mid-IR at a distance of 4 m and 32 scans at 10 s. SVM-DA resulted in the best statistical technique for a discrimination performance of 97%. PLS-DA accurately predicted over 94% and NN 88%.

  5. Methods on estimation of the evaporation from water surface

    International Nuclear Information System (INIS)

    Trajanovska, Lidija; Tanushevska, Dushanka; Aleksovska, Nina

    2001-01-01

    The whole world water supply on the Earth is in close dependence on hydrological cycle connected with water circulation at Earth-Atmosphere route through evaporation, precipitation and water runoff. Evaporation exists worldwide where the atmosphere is unsatiated of water steam (when there is humidity in short supply) and it depends on climatic conditions in some regions. The purpose of this paper is to determine a method for estimation of evaporation of natural water surface in our areas, that means its determination as exact as possible. (Original)

  6. Composites incorporated a conductive polymer nanofiber network

    Science.gov (United States)

    Pozzo, Lilo Danielle; Newbloom, Gregory

    2017-04-11

    Methods of forming composites that incorporate networks of conductive polymer nanofibers are provided. Networks of less-than conductive polymers are first formed and then doped with a chemical dopant to provide networks of conductive polymers. The networks of conductive polymers are then incorporated into a matrix in order to improve the conductivity of the matrix. The formed composites are useful as conductive coatings for applications including electromagnetic energy management on exterior surfaces of vehicles.

  7. Two Surface-Tension Formulations For The Level Set Interface-Tracking Method

    International Nuclear Information System (INIS)

    Shepel, S.V.; Smith, B.L.

    2005-01-01

    The paper describes a comparative study of two surface-tension models for the Level Set interface tracking method. In both models, the surface tension is represented as a body force, concentrated near the interface, but the technical implementation of the two options is different. The first is based on a traditional Level Set approach, in which the surface tension is distributed over a narrow band around the interface using a smoothed Delta function. In the second model, which is based on the integral form of the fluid-flow equations, the force is imposed only in those computational cells through which the interface passes. Both models have been incorporated into the Finite-Element/Finite-Volume Level Set method, previously implemented into the commercial Computational Fluid Dynamics (CFD) code CFX-4. A critical evaluation of the two models, undertaken in the context of four standard Level Set benchmark problems, shows that the first model, based on the smoothed Delta function approach, is the more general, and more robust, of the two. (author)

  8. Surface plasmon-enhanced localized electric field in organic light-emitting diodes by incorporating silver nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying-Chung; Gao, Chia-Yuan [Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Chen, Kan-Lin [Department of Electronic Engineering, Fortune Institute of Technology, Kaohsiung, Taiwan (China); Huang, Chien-Jung, E-mail: chien@nuk.edu.tw [Department of Applied Physics, National University of Kaohsiung, Kaohsiung, Taiwan (China)

    2014-03-01

    Highlights: • A higher luminance and electron-injection ability are obtained when the mean cluster size of SNCs is 34 nm. • SPRE is the crucial factor to contribute the electron injection. • SPRE induced the enhanced localized electric field around the Ag NPs. - Abstract: The influence of silver nanoclusters (SNCs) on the performance of organic light-emitting diodes is investigated in this study. The SNCs are introduced between the electron-injection layer and cathode alumina by means of thermal evaporation, resulting that different absorption peaks of SNCs were formed. A higher luminance and electron-injection ability are obtained when the mean cluster size is 34 nm. The surface-enhanced Raman scattering spectroscopy reveals that the localized electric field around the SNCs is enhanced, resulting in an increase in electron injection from cathode electrode.

  9. Evaluation of surface renewal and flux-variance methods above agricultural and forest surfaces

    Science.gov (United States)

    Fischer, M.; Katul, G. G.; Noormets, A.; Poznikova, G.; Domec, J. C.; Trnka, M.; King, J. S.

    2016-12-01

    Measurements of turbulent surface energy fluxes are of high interest in agriculture and forest research. During last decades, eddy covariance (EC), has been adopted as the most commonly used micrometeorological method for measuring fluxes of greenhouse gases, energy and other scalars at the surface-atmosphere interface. Despite its robustness and accuracy, the costs of EC hinder its deployment at some research experiments and in practice like e.g. for irrigation scheduling. Therefore, testing and development of other cost-effective methods is of high interest. In our study, we tested performance of surface renewal (SR) and flux variance method (FV) for estimates of sensible heat flux density. Surface renewal method is based on the concept of non-random transport of scalars via so-called coherent structures which if accurately identified can be used for the computing of associated flux. Flux variance method predicts the flux from the scalar variance following the surface-layer similarity theory. We tested SR and FV against EC in three types of ecosystem with very distinct aerodynamic properties. First site was represented by agricultural wheat field in the Czech Republic. The second site was a 20-m tall mixed deciduous wetland forest on the coast of North Carolina, USA. The third site was represented by pine-switchgrass intercropping agro-forestry system located in coastal plain of North Carolina, USA. Apart from solving the coherent structures in a SR framework from the structure functions (representing the most common approach), we applied ramp wavelet detection scheme to test the hypothesis that the duration and amplitudes of the coherent structures are normally distributed within the particular 30-minutes time intervals and so just the estimates of their averages is sufficient for the accurate flux determination. Further, we tested whether the orthonormal wavelet thresholding can be used for isolating of the coherent structure scales which are associated with

  10. Comparison of dimensionality reduction methods for wood surface inspection

    Science.gov (United States)

    Niskanen, Matti; Silven, Olli

    2003-04-01

    Dimensionality reduction methods for visualization map the original high-dimensional data typically into two dimensions. Mapping preserves the important information of the data, and in order to be useful, fulfils the needs of a human observer. We have proposed a self-organizing map (SOM)- based approach for visual surface inspection. The method provides the advantages of unsupervised learning and an intuitive user interface that allows one to very easily set and tune the class boundaries based on observations made on visualization, for example, to adapt to changing conditions or material. There are, however, some problems with a SOM. It does not address the true distances between data, and it has a tendency to ignore rare samples in the training set at the expense of more accurate representation of common samples. In this paper, some alternative methods for a SOM are evaluated. These methods, PCA, MDS, LLE, ISOMAP, and GTM, are used to reduce dimensionality in order to visualize the data. Their principal differences are discussed and performances quantitatively evaluated in a few special classification cases, such as in wood inspection using centile features. For the test material experimented with, SOM and GTM outperform the others when classification performance is considered. For data mining kinds of applications, ISOMAP and LLE appear to be more promising methods.

  11. A new surface resistance measurement method with ultrahigh sensitivity

    International Nuclear Information System (INIS)

    Liang, Changnian.

    1993-01-01

    A superconducting niobium triaxial cavity has been designed and fabricated to study residual surface resistance of planar superconducting materials. The edge of a 25.4 mm or larger diameter sample in the triaxial cavity is located outside the strong field region. Therefore, the edge effects and possible losses between the thin film and the substrate have been minimized, ensuring that induced RF losses are intrinsic to the test material. The fundamental resonant frequency of the cavity is the same as the working frequency of CEBAF cavities. The cavity has a compact size compared to its TE 011 counterpart, which makes it more sensitive to the sample's loss. For even higher sensitivity, a calorimetry method has been used to measure the RF losses on the superconducting sample. At 2 K, a 2 μK temperature change can be resolved by using carbon resistor sensors. The temperature distribution caused by RF heating is measured by 16 carbon composition resistor sensors. A 0.05 μW heating power can be detected as such a resolution, which translates to a surface resistance of 0.02 nΩ at a surface magnetic field of 52 Oe. This is the most sensitive device for surface resistance measurements to date. In addition, losses due to the indium seal, coupling probes, field emission sites other than the sample, and all of the high field resonator surface, are excluded in the measurement. Surface resistance of both niobium and high-Tc superconducting thin films has been measured. A low R s of 35.2 μΩ was measured for a 25.4 mm diameter YBa 2 Cu 3 O 7 thin film at 1.5 GHz and at 2 K. The measurement result is the first result for a large area epitaxially grown thin film sample at such a low RF frequency. The abrupt disappearance of multipacting between two parallel plates has been observed and monitored with the 16 temperature mapping sensors. Field emission or some field dependent anomalous RF losses on the niobium plate have also been observed

  12. Benchmarking a computational design method for the incorporation of metal ion-binding sites at symmetric protein interfaces.

    Science.gov (United States)

    Hansen, William A; Khare, Sagar D

    2017-08-01

    The design of novel metal-ion binding sites along symmetric axes in protein oligomers could provide new avenues for metalloenzyme design, construction of protein-based nanomaterials and novel ion transport systems. Here, we describe a computational design method, symmetric protein recursive ion-cofactor sampling (SyPRIS), for locating constellations of backbone positions within oligomeric protein structures that are capable of supporting desired symmetrically coordinated metal ion(s) chelated by sidechains (chelant model). Using SyPRIS on a curated benchmark set of protein structures with symmetric metal binding sites, we found high recovery of native metal coordinating rotamers: in 65 of the 67 (97.0%) cases, native rotamers featured in the best scoring model while in the remaining cases native rotamers were found within the top three scoring models. In a second test, chelant models were crossmatched against protein structures with identical cyclic symmetry. In addition to recovering all native placements, 10.4% (8939/86013) of the non-native placements, had acceptable geometric compatibility scores. Discrimination between native and non-native metal site placements was further enhanced upon constrained energy minimization using the Rosetta energy function. Upon sequence design of the surrounding first-shell residues, we found further stabilization of native placements and a small but significant (1.7%) number of non-native placement-based sites with favorable Rosetta energies, indicating their designability in existing protein interfaces. The generality of the SyPRIS approach allows design of novel symmetric metal sites including with non-natural amino acid sidechains, and should enable the predictive incorporation of a variety of metal-containing cofactors at symmetric protein interfaces. © 2017 The Protein Society.

  13. Incorporating High-Frequency Physiologic Data Using Computational Dictionary Learning Improves Prediction of Delayed Cerebral Ischemia Compared to Existing Methods.

    Science.gov (United States)

    Megjhani, Murad; Terilli, Kalijah; Frey, Hans-Peter; Velazquez, Angela G; Doyle, Kevin William; Connolly, Edward Sander; Roh, David Jinou; Agarwal, Sachin; Claassen, Jan; Elhadad, Noemie; Park, Soojin

    2018-01-01

    Accurate prediction of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) can be critical for planning interventions to prevent poor neurological outcome. This paper presents a model using convolution dictionary learning to extract features from physiological data available from bedside monitors. We develop and validate a prediction model for DCI after SAH, demonstrating improved precision over standard methods alone. 488 consecutive SAH admissions from 2006 to 2014 to a tertiary care hospital were included. Models were trained on 80%, while 20% were set aside for validation testing. Modified Fisher Scale was considered the standard grading scale in clinical use; baseline features also analyzed included age, sex, Hunt-Hess, and Glasgow Coma Scales. An unsupervised approach using convolution dictionary learning was used to extract features from physiological time series (systolic blood pressure and diastolic blood pressure, heart rate, respiratory rate, and oxygen saturation). Classifiers (partial least squares and linear and kernel support vector machines) were trained on feature subsets of the derivation dataset. Models were applied to the validation dataset. The performances of the best classifiers on the validation dataset are reported by feature subset. Standard grading scale (mFS): AUC 0.54. Combined demographics and grading scales (baseline features): AUC 0.63. Kernel derived physiologic features: AUC 0.66. Combined baseline and physiologic features with redundant feature reduction: AUC 0.71 on derivation dataset and 0.78 on validation dataset. Current DCI prediction tools rely on admission imaging and are advantageously simple to employ. However, using an agnostic and computationally inexpensive learning approach for high-frequency physiologic time series data, we demonstrated that we could incorporate individual physiologic data to achieve higher classification accuracy.

  14. Evaluation of Surface Treatment Methods on the Bond Strength of Zirconia Ceramics Systems, Resin Cements and Tooth Surface

    Directory of Open Access Journals (Sweden)

    Akkuş Emek

    2015-07-01

    Full Text Available Objectives: To compare the effects of airborne-particle abrasion (APA and tribochemical silica coating (TSC surface treatment methods on the shear bond strength of zirconia ceramics systems, resin cements and tooth surface

  15. A plateau-valley separation method for multifunctional surfaces characterization

    DEFF Research Database (Denmark)

    Godi, Alessandro; Kühle, A.; De Chiffre, Leonardo

    2012-01-01

    Turned multifunctional surfaces are a new typology of textured surfaces presenting a flat plateau region and deterministically distributed lubricant reservoirs. Existing standards are not suitable for the characterization of such surfaces, providing at times values without physical meaning. A new...

  16. Innovation of a design method (MoIST) that incorporates non-traditional 'soft' systems science into traditional 'hard' information systems design

    OpenAIRE

    Nwako, Judith

    2007-01-01

    The research explores ways of making the information systems development process\\ud more effective. The thesis documents an original design method. This is the method\\ud of incorporating Systems thinking into Information Systems Design (MoIST). The\\ud thesis demonstrates that MoIST improves information systems design and adds to\\ud the effective arsenal of methods that already exist.\\ud The Computer Science literature has identified some weaknesses in the software\\ud development methodologies...

  17. Advanced Methods for Incorporating Solar Energy Technologies into Electric Sector Capacity-Expansion Models: Literature Review and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, P.; Eurek, K.; Margolis, R.

    2014-07-01

    Because solar power is a rapidly growing component of the electricity system, robust representations of solar technologies should be included in capacity-expansion models. This is a challenge because modeling the electricity system--and, in particular, modeling solar integration within that system--is a complex endeavor. This report highlights the major challenges of incorporating solar technologies into capacity-expansion models and shows examples of how specific models address those challenges. These challenges include modeling non-dispatchable technologies, determining which solar technologies to model, choosing a spatial resolution, incorporating a solar resource assessment, and accounting for solar generation variability and uncertainty.

  18. Biological methods used to assess surface water quality

    Directory of Open Access Journals (Sweden)

    Szczerbiñska Natalia

    2015-12-01

    Full Text Available In accordance with the guidelines of the Water Framework Directive 2000/60 (WFD, both ecological and chemical statuses determine the assessment of surface waters. The profile of ecological status is based on the analysis of various biological components, and physicochemical and hydromorphological indicators complement this assessment. The aim of this article is to present the biological methods used in the assessment of water status with a special focus on bioassay, as well as to provide a review of methods of monitoring water status. Biological test methods include both biomonitoring and bioanalytics. Water biomonitoring is used to assess and forecast the status of water. These studies aim to collect data on water pollution and forecast its impact. Biomonitoring uses organisms which are characterized by particular vulnerability to contaminants. Bioindicator organisms are algae, fungi, bacteria, larval invertebrates, cyanobacteria, macroinvertebrates, and fish. Bioanalytics is based on the receptors of contaminants that can be biologically active substances. In bioanalytics, biosensors such as viruses, bacteria, antibodies, enzymes, and biotests are used to assess degrees of pollution.

  19. Integral methods for shallow free-surface flows with separation

    DEFF Research Database (Denmark)

    Watanabe, S.; Putkaradze, V.; Bohr, Tomas

    2003-01-01

    eddy and separated flow. Assuming a variable radial velocity profile as in Karman-Pohlhausen's method, we obtain a system of two ordinary differential equations for stationary states that can smoothly go through the jump. Solutions of the system are in good agreement with experiments. For the flow down...... an inclined plane we take a similar approach and derive a simple model in which the velocity profile is not restricted to a parabolic or self-similar form. Two types of solutions with large surface distortions are found: solitary, kink-like propagating fronts, obtained when the flow rate is suddenly changed......, and stationary jumps, obtained, for instance, behind a sluice gate. We then include time dependence in the model to study the stability of these waves. This allows us to distinguish between sub- and supercritical flows by calculating dispersion relations for wavelengths of the order of the width of the layer....

  20. Method for producing high surface area chromia materials for catalysis

    Science.gov (United States)

    Gash, Alexander E [Brentwood, CA; Satcher, Joe [Patterson, CA; Tillotson, Thomas [Tracy, CA; Hrubesh, Lawrence [Pleasanton, CA; Simpson, Randall [Livermore, CA

    2007-05-01

    Nanostructured chromium(III)-oxide-based materials using sol-gel processing and a synthetic route for producing such materials are disclosed herein. Monolithic aerogels and xerogels having surface areas between 150 m.sup.2/g and 520 m.sup.2/g have been produced. The synthetic method employs the use of stable and inexpensive hydrated-chromium(III) inorganic salts and common solvents such as water, ethanol, methanol, 1-propanol, t-butanol, 2-ethoxy ethanol, and ethylene glycol, DMSO, and dimethyl formamide. The synthesis involves the dissolution of the metal salt in a solvent followed by an addition of a proton scavenger, such as an epoxide, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively.

  1. A surface acoustic wave response detection method for passive wireless torque sensor

    Science.gov (United States)

    Fan, Yanping; Kong, Ping; Qi, Hongli; Liu, Hongye; Ji, Xiaojun

    2018-01-01

    This paper presents an effective surface acoustic wave (SAW) response detection method for the passive wireless SAW torque sensor to improve the measurement accuracy. An analysis was conducted on the relationship between the response energy-entropy and the bandwidth of SAW resonator (SAWR). A self-correlation method was modified to suppress the blurred white noise and highlight the attenuation characteristic of wireless SAW response. The SAW response was detected according to both the variation and the duration of energy-entropy ascension of an acquired RF signal. Numerical simulation results showed that the SAW response can be detected even when the signal-to-noise ratio (SNR) is 6dB. The proposed SAW response detection method was evaluated with several experiments at different conditions. The SAW response can be well distinguished from the sinusoidal signal and the noise. The performance of the SAW torque measurement system incorporating the detection method was tested. The obtained repeatability error was 0.23% and the linearity was 0.9934, indicating the validity of the detection method.

  2. Modified surface testing method for large convex aspheric surfaces based on diffraction optics.

    Science.gov (United States)

    Zhang, Haidong; Wang, Xiaokun; Xue, Donglin; Zhang, Xuejun

    2017-12-01

    Large convex aspheric optical elements have been widely applied in advanced optical systems, which have presented a challenging metrology problem. Conventional testing methods cannot satisfy the demand gradually with the change of definition of "large." A modified method is proposed in this paper, which utilizes a relatively small computer-generated hologram and an illumination lens with certain feasibility to measure the large convex aspherics. Two example systems are designed to demonstrate the applicability, and also, the sensitivity of this configuration is analyzed, which proves the accuracy of the configuration can be better than 6 nm with careful alignment and calibration of the illumination lens in advance. Design examples and analysis show that this configuration is applicable to measure the large convex aspheric surfaces.

  3. Progression towards optimization of viscosity of highly concentrated carbonaceous solid-water slurries by incorporating and modifying surface chemistry parameters with and without additives

    Science.gov (United States)

    Mukherjee, Amrita

    Carbonaceous solid-water slurries (CSWS) are concentrated suspensions of coal, petcoke bitumen, pitch etc. in water which are used as feedstock for gasifiers. The high solid loading (60-75 wt.%) in the slurry increases CSWS viscosity. For easier handling and pumping of these highly loaded mixtures, low viscosities are desirable. Depending on the nature of the carbonaceous solid, solids loading in the slurry and the particle size distribution, viscosity of a slurry can vary significantly. Ability to accurately predict the viscosity of a slurry will provide a better control over the design of slurry transport system and for viscosity optimization. The existing viscosity prediction models were originally developed for hard-sphere suspensions and therefore do not take into account surface chemistry. As a result, the viscosity predictions using these models for CSWS are not very accurate. Additives are commonly added to decrease viscosity of the CSWS by altering the surface chemistry. Since additives are specific to CSWS, selection of appropriate additives is crucial. The goal of this research was to aid in optimization of CSWS viscosity through improved prediction and selection of appropriate additive. To incorporate effect of surface chemistry in the models predicting suspension viscosity, the effect of the different interfacial interactions caused by different surface chemistries has to be accounted for. Slurries of five carbonaceous solids with varying O/C ratio (to represent different surface chemistry parameters) were used for the study. To determine the interparticle interactions of the carbonaceous solids in water, interfacial energies were calculated on the basis of surface chemistries, characterized by contact angles and zeta potential measurements. The carbonaceous solid particles in the slurries were assumed to be spherical. Polar interaction energy (hydrophobic/hydrophilic interaction energy), which was observed to be 5-6 orders of magnitude higher than the

  4. Collagen hydrogels incorporated with surface-aminated mesoporous nanobioactive glass: Improvement of physicochemical stability and mechanical properties is effective for hard tissue engineering.

    Science.gov (United States)

    El-Fiqi, Ahmed; Lee, Jae Ho; Lee, Eun-Jung; Kim, Hae-Won

    2013-12-01

    Collagen (Col) hydrogels have poor physicochemical and mechanical properties and are susceptible to substantial shrinkage during cell culture, which limits their potential applications in hard tissue engineering. Here, we developed novel nanocomposite hydrogels made of collagen and mesoporous bioactive glass nanoparticles (mBGns) with surface amination, and addressed the effects of mBGn addition (Col:mBG = 2:1, 1:1 and 1:2) and its surface amination on the physicochemical and mechanical properties of the hydrogels. The amination of mBGn was shown to enable chemical bonding with collagen molecules. As a result, the nanocomposite hydrogels exhibited a significantly improved physicochemical and mechanical stability. The hydrolytic and enzymatic degradation of the Col-mBGn hydrogels were slowed down due to the incorporation of mBGn and its surface amination. The mechanical properties of the hydrogels, specifically the resistance to loading as well as the stiffness, significantly increased with the addition of mBGn and its aminated form, as assessed by a dynamic mechanical analysis. Mesenchymal stem cells cultivated within the Col-mBGn hydrogels were highly viable, with enhanced cytoskeletal extensions, due to the addition of surface aminated mBGn. While the Col hydrogel showed extensive shrinkage (down to ∼20% of initial size) during a few days of culture, the shrinkage of the mBGn-added hydrogel was substantially reduced, and the aminated mBGn-added hydrogel had no observable shrinkage over 21 days. Results demonstrated the effective roles of aminated mBGn in significantly improving the physicochemical and mechanical properties of Col hydrogel, which are ultimately favorable for applications in stem cell culture for bone tissue engineering. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  5. Rapid surface enhanced Raman scattering detection method for chloramphenicol residues

    Science.gov (United States)

    Ji, Wei; Yao, Weirong

    2015-06-01

    Chloramphenicol (CAP) is a widely used amide alcohol antibiotics, which has been banned from using in food producing animals in many countries. In this study, surface enhanced Raman scattering (SERS) coupled with gold colloidal nanoparticles was used for the rapid analysis of CAP. Density functional theory (DFT) calculations were conducted with Gaussian 03 at the B3LYP level using the 3-21G(d) and 6-31G(d) basis sets to analyze the assignment of vibrations. Affirmatively, the theoretical Raman spectrum of CAP was in complete agreement with the experimental spectrum. They both exhibited three strong peaks characteristic of CAP at 1104 cm-1, 1344 cm-1, 1596 cm-1, which were used for rapid qualitative analysis of CAP residues in food samples. The use of SERS as a method for the measurements of CAP was explored by comparing use of different solvents, gold colloidal nanoparticles concentration and absorption time. The method of the detection limit was determined as 0.1 μg/mL using optimum conditions. The Raman peak at 1344 cm-1 was used as the index for quantitative analysis of CAP in food samples, with a linear correlation of R2 = 0.9802. Quantitative analysis of CAP residues in foods revealed that the SERS technique with gold colloidal nanoparticles was sensitive and of a good stability and linear correlation, and suited for rapid analysis of CAP residue in a variety of food samples.

  6. Method for Qualification of Coatings Applied to Wet Surfaces

    Science.gov (United States)

    2009-12-16

    The field application of a pipeline repair or rehabilitation coating usually cannot wait until ambient conditions become optimal. In a humid environment, water can condense on the pipe surface because the pipe surface is usually cooler than the ambie...

  7. Response Surface Methods For Spatially-Resolved Optical Measurement Techniques

    Science.gov (United States)

    Danehy, P. M.; Dorrington, A. A.; Cutler, A. D.; DeLoach, R.

    2003-01-01

    Response surface methods (or methodology), RSM, have been applied to improve data quality for two vastly different spatially-resolved optical measurement techniques. In the first application, modern design of experiments (MDOE) methods, including RSM, are employed to map the temperature field in a direct-connect supersonic combustion test facility at NASA Langley Research Center. The laser-based measurement technique known as coherent anti-Stokes Raman spectroscopy (CARS) is used to measure temperature at various locations in the combustor. RSM is then used to develop temperature maps of the flow. Even though the temperature fluctuations at a single point in the flowfield have a standard deviation on the order of 300 K, RSM provides analytic fits to the data having 95% confidence interval half width uncertainties in the fit as low as +/- 30 K. Methods of optimizing future CARS experiments are explored. The second application of RSM is to quantify the shape of a 5-meter diameter, ultra-lightweight, inflatable space antenna at NASA Langley Research Center. Photogrammetry is used to simultaneously measure the shape of the antenna at approximately 500 discrete spatial locations. RSM allows an analytic model to be developed that describes the shape of the majority of the antenna with an uncertainty of 0.4 mm, with 95% confidence. This model would allow a quantitative comparison between the actual shape of the antenna and the original design shape. Accurately determining this shape also allows confident interpolation between the measured points. Such a model could, for example, be used for ray tracing of radio-frequency waves up to 95 GHz. to predict the performance of the antenna.

  8. ROUGHNESS ON WOOD SURFACES AND ROUGHNESS MEASUREMENT METHODS

    OpenAIRE

    İsmail Aydın; Gürsel Çolakoğlu

    2003-01-01

    Some visual characteristics of wood such as color, pattern and texture determine the quality of manufactured products. Surface properties of wood material are important both in production and marketing after production. Initial studies related to the roughness of wood surface were begun in early 1950’s. However, no general agreed standardization can not have been developed for wood surfaces. Surface roughness of wood is function of the production process, product type and the natural anatomic...

  9. A New Method Based on TOPSIS and Response Surface Method for MCDM Problems with Interval Numbers

    Directory of Open Access Journals (Sweden)

    Peng Wang

    2015-01-01

    Full Text Available As the preference of design maker (DM is always ambiguous, we have to face many multiple criteria decision-making (MCDM problems with interval numbers in our daily life. Though there have been some methods applied to solve this sort of problem, it is always complex to comprehend and sometimes difficult to implement. The calculation processes are always ineffective when a new alternative is added or removed. In view of the weakness like this, this paper presents a new method based on TOPSIS and response surface method (RSM for MCDM problems with interval numbers, RSM-TOPSIS-IN for short. The key point of this approach is the application of deviation degree matrix, which ensures that the DM can get a simple response surface (RS model to rank the alternatives. In order to demonstrate the feasibility and effectiveness of the proposed method, three illustrative MCMD problems with interval numbers are analysed, including (a selection of investment program, (b selection of a right partner, and (c assessment of road transport technologies. The contrast of ranking results shows that the RSM-TOPSIS-IN method is in good agreement with those derived by earlier researchers, indicating it is suitable to solve MCDM problems with interval numbers.

  10. A facile method for simulating randomly rough membrane surface associated with interface behaviors

    Science.gov (United States)

    Qu, Xiaolu; Cai, Xiang; Zhang, Meijia; Lin, Hongjun; Leihong, Zhao; Liao, Bao-Qiang

    2018-01-01

    Modeling rough surfaces has emerged as a distinct discipline of considerable research interest in interface behaviors including membrane fouling. In this paper, a facile method was proposed to simulate rough membrane surface morphology. Natural membrane surface was found to be randomly rough, and its height distribution obeys Gaussian distribution. A new method which combines spectrum method, Gaussian distribution and Fourier transform technique was deduced. Simulation of the rough membrane surface showed high similarity in terms of statistical roughness and height distribution between the simulated surface and the real membrane surface, indicating feasibility of the new method. It was found that, correlation length (l) and the number of superposed ridges (N) are key parameters affecting the simulated membrane surface morphology. This new method has evident advantages over conventional modeling methods The proposed method for randomly rough membrane surface modeling could be potentially used to quantify the interfacial interactions between two rough surfaces, giving implications for membrane fouling mitigation.

  11. Cargill Incorporated

    Science.gov (United States)

    Cargill, Incorporated, 518 East Fourth Street, Watkins Glen, New York 14891 has applied to the U.S. Environmental Protection Agency (EPA) under the provisions of the Safe Drinking Water Act, 42 U.S.C. 300f et. seq (the Act), for a new Underground Injection

  12. Simulation of dissolution in porous media in three dimensions with lattice Boltzmann, finite-volume, and surface-rescaling methods

    Science.gov (United States)

    Gray, F.; Cen, J.; Boek, E. S.

    2016-10-01

    We present a pore-scale dissolution model for the simulation of reactive transport in complex porous media such as those encountered in carbon-storage injection processes. We couple a lattice Boltzmann model for flow calculation with a finite-volume method for solving chemical transport equations, and allow the computational grid to change as mineral surfaces are dissolved according to first-order reaction kinetics. We appraise this scheme for use with high Péclet number flows in three-dimensional geometries and show how the popular first-order convection scheme is affected by severe numerical diffusion when grid Péclet numbers exceed unity, and confirm that this can be overcome relatively easily by using a second-order method in conjunction with a flux-limiter function. We then propose a surface rescaling method which uses parabolic elements to counteract errors in surface area exposed by the Cartesian grid and avoid the use of more complex embedded surface methods when surface reaction kinetics are incorporated. Finally, we compute dissolution in an image of a real porous limestone rock sample injected with HCl for different Péclet numbers and obtain dissolution patterns in concordance with theory and experimental observation. A low injection flow rate was shown to lead to erosion of the pore space concentrated at the face of the rock, whereas a high flow rate leads to wormhole formation.

  13. Nanoscale array structures suitable for surface enhanced raman scattering and methods related thereto

    Science.gov (United States)

    Bond, Tiziana C.; Miles, Robin; Davidson, James C.; Liu, Gang Logan

    2014-07-22

    Methods for fabricating nanoscale array structures suitable for surface enhanced Raman scattering, structures thus obtained, and methods to characterize the nanoscale array structures suitable for surface enhanced Raman scattering. Nanoscale array structures may comprise nanotrees, nanorecesses and tapered nanopillars.

  14. Recent Progresses in Incorporating Human Land-Water Management into Global Land Surface Models Toward Their Integration into Earth System Models

    Science.gov (United States)

    Pokhrel, Yadu N.; Hanasaki, Naota; Wada, Yoshihide; Kim, Hyungjun

    2016-01-01

    The global water cycle has been profoundly affected by human land-water management. As the changes in the water cycle on land can affect the functioning of a wide range of biophysical and biogeochemical processes of the Earth system, it is essential to represent human land-water management in Earth system models (ESMs). During the recent past, noteworthy progress has been made in large-scale modeling of human impacts on the water cycle but sufficient advancements have not yet been made in integrating the newly developed schemes into ESMs. This study reviews the progresses made in incorporating human factors in large-scale hydrological models and their integration into ESMs. The study focuses primarily on the recent advancements and existing challenges in incorporating human impacts in global land surface models (LSMs) as a way forward to the development of ESMs with humans as integral components, but a brief review of global hydrological models (GHMs) is also provided. The study begins with the general overview of human impacts on the water cycle. Then, the algorithms currently employed to represent irrigation, reservoir operation, and groundwater pumping are discussed. Next, methodological deficiencies in current modeling approaches and existing challenges are identified. Furthermore, light is shed on the sources of uncertainties associated with model parameterizations, grid resolution, and datasets used for forcing and validation. Finally, representing human land-water management in LSMs is highlighted as an important research direction toward developing integrated models using ESM frameworks for the holistic study of human-water interactions within the Earths system.

  15. Development of an atmospheric diffusion numerical model for a nuclear facility. Numerical calculation method incorporating building effects

    International Nuclear Information System (INIS)

    Sada, Koichi; Michioka, Takenobu; Ichikawa, Yoichi

    2002-01-01

    Because effluent gas is sometimes released from low positions, viz., near the ground surface and around buildings, the effects caused by buildings within the site area are not negligible for gas diffusion predictions. For these reasons, the effects caused by buildings for gas diffusion are considered under the terrain following calculation coordinate system in this report. Numerical calculation meshes on the ground surface are treated as the building with the adaptation of wall function techniques of turbulent quantities in the flow calculations using a turbulence closure model. The reflection conditions of released particles on building surfaces are taken into consideration in the diffusion calculation using the Lagrangian particle model. Obtained flow and diffusion calculation results are compared with those of wind tunnel experiments around the building. It was apparent that features observed in a wind tunnel, viz., the formation of cavity regions behind the building and the gas diffusion to the ground surface behind the building, are also obtained by numerical calculation. (author)

  16. Relationships between response surfaces for tablet characteristics of placebo and API-containing tablets manufactured by direct compression method.

    Science.gov (United States)

    Hayashi, Yoshihiro; Tsuji, Takahiro; Shirotori, Kaede; Oishi, Takuya; Kosugi, Atsushi; Kumada, Shungo; Hirai, Daijiro; Takayama, Kozo; Onuki, Yoshinori

    2017-10-30

    In this study, we evaluated the correlation between the response surfaces for the tablet characteristics of placebo and active pharmaceutical ingredient (API)-containing tablets. The quantities of lactose, cornstarch, and microcrystalline cellulose were chosen as the formulation factors. Ten tablet formulations were prepared. The tensile strength (TS) and disintegration time (DT) of tablets were measured as tablet characteristics. The response surfaces for TS and DT were estimated using a nonlinear response surface method incorporating multivariate spline interpolation, and were then compared with those of placebo tablets. A correlation was clearly observed for TS and DT of all APIs, although the value of the response surfaces for TS and DT was highly dependent on the type of API used. Based on this knowledge, the response surfaces for TS and DT of API-containing tablets were predicted from only two and four formulations using regression expression and placebo tablet data, respectively. The results from the evaluation of prediction accuracy showed that this method accurately predicted TS and DT, suggesting that it could construct a reliable response surface for TS and DT with a small number of samples. This technique assists in the effective estimation of the relationships between design variables and pharmaceutical responses during pharmaceutical development. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Radiation induced diffusion as a method to protect surface

    International Nuclear Information System (INIS)

    Baumvol, I.J.R.

    1980-01-01

    Radiation induced diffusion forms a coating adeherent and without interface on the surface of metalic substrates. This coating improves the behaviour of metal to corrosion and abrasion. The effect of radiation induced diffusion of tin and calcium on pure iron surface is described and analyzed in this work. (author) [pt

  18. Marker-based reconstruction of the kinematics of a chain of segments: a new method that incorporates joint kinematic constraints.

    Science.gov (United States)

    Klous, Miriam; Klous, Sander

    2010-07-01

    The aim of skin-marker-based motion analysis is to reconstruct the motion of a kinematical model from noisy measured motion of skin markers. Existing kinematic models for reconstruction of chains of segments can be divided into two categories: analytical methods that do not take joint constraints into account and numerical global optimization methods that do take joint constraints into account but require numerical optimization of a large number of degrees of freedom, especially when the number of segments increases. In this study, a new and largely analytical method for a chain of rigid bodies is presented, interconnected in spherical joints (chain-method). In this method, the number of generalized coordinates to be determined through numerical optimization is three, irrespective of the number of segments. This new method is compared with the analytical method of Veldpaus et al. [1988, "A Least-Squares Algorithm for the Equiform Transformation From Spatial Marker Co-Ordinates," J. Biomech., 21, pp. 45-54] (Veldpaus-method, a method of the first category) and the numerical global optimization method of Lu and O'Connor [1999, "Bone Position Estimation From Skin-Marker Co-Ordinates Using Global Optimization With Joint Constraints," J. Biomech., 32, pp. 129-134] (Lu-method, a method of the second category) regarding the effects of continuous noise simulating skin movement artifacts and regarding systematic errors in joint constraints. The study is based on simulated data to allow a comparison of the results of the different algorithms with true (noise- and error-free) marker locations. Results indicate a clear trend that accuracy for the chain-method is higher than the Veldpaus-method and similar to the Lu-method. Because large parts of the equations in the chain-method can be solved analytically, the speed of convergence in this method is substantially higher than in the Lu-method. With only three segments, the average number of required iterations with the chain-method

  19. Evaluation of an IBAD thin-film process as an alternative method for surface incorporation of bioceramics on dental implants: a study in dogs Avaliação de um recobrimento de baixa espessura processado pela deposição assistida por feixe iônico como alternativa para a incorporação de biocerâmicas em implantes dentários: estudo em cães

    Directory of Open Access Journals (Sweden)

    Paulo G. Coelho

    2005-03-01

    Full Text Available Thin-film bioceramic coatings are potential alternatives to overcome the limitations provided by other commercially available coating techniques like PSHA, where variable bioceramic dissolution added to a metalloceramic weak link are process- inherent. The purpose of this investigation was to determine the overall and site specific (to 0.5 mm from implant surface levels of osseoactivity around a thin-film (IBAD processed coated titanium alloy implant versus a non surface modified (sand-blasted/acid etched titanium alloy implant in a canine model. The surgical model comprised the proximal tibiae epiphyses with four implants placed in each limb remaining for 2 and 4 weeks in-vivo. 10 mg/Kg oxytetracycline was administered 48 hours prior to euthanization. The limbs were retrieved by sharp dissection, reduced to blocks, and subsequently nondecalcified processed for fluorescent microscopy. Micrographs (20x mag were acquired around the implant perimeter and merged for overall biological response evaluations, and four micrographs (40x mag. subdivided in rectangles were acquired along one of the implant sides for tetracycline labeled area fraction quantification. The results showed biocompatible and osseoconductive properties for the thin-film coated and uncoated titanium alloy implants. Tetracycline labeled area fraction analyses showed that the thin-film coated implants presented significantly higher overall and site specific osseoactivity levels at 2 and 4 weeks. The site specific osseoactivity values were significantly higher compared to overall values for control and thin-film coated implants at both times in-vivo. According to the results obtained in this study, thin-film coated implants enhanced biological response at the early implantation times evaluated.Recobrimentos biocerâmicos de baixa espessura são potenciais alternativas para compensar as limitações de outros recobrimentos biocerâmicos disponíveis comercialmente como o plasma spray

  20. Effect of chlorine treatment on inhibition of E. coli serogroup O2 incorporation into 7-day-old biofilm on polyvinylchloride surface.

    Science.gov (United States)

    Maharjan, P; Dey, S; Huff, G; Zhang, W; Phillips, G K; Watkins, S

    2017-08-01

    Poultry waterlines are constructed using polyvinylchloride (PVC) material on which bacterial biofilm can easily form. Biofilm can harbor pathogens including avian pathogenic E. coli (APEC) strains. An in vitro evaluation was performed to determine if E. coli sero group O2 (avian pathogenic) could attach on a PVC surface that had pre-formed biofilm and if this phenomenon could be affected when water was treated with chlorine. Initially, biofilm growth was induced in PVC test coupons (15.16 cm2) for a 7-day period mimicking the waterline scenario in the first wk of poultry brooding; and then this biofilm was challenged with E. coli O2 seeded water in presence/absence of chlorine treatment. After rinsing, test coupons were sampled for bacterial (APC) and E. coli O2 enumeration at various occasions post seeding the pathogen and chlorine treatment. Day 7 APC recovered from coupons was 4.35 log10 cfu/cm2 in trial 1 and 3.66 log10 cfu/cm2 in trial 2. E. coli O2 was not recovered from chlorine treated test coupons (P  3 log10 cfu/cm2 in trial 1 and > 2 log10 cfu/cm2 in trial 2). This study suggests that E. coli O2 can incorporate into pre-formed biofilm on a PVC surface within 24 h if water sanitation is not present, and the attachment time of the pathogen can prolong in the absence of already formed biofilm. © 2017 Poultry Science Association Inc.

  1. A method of and apparatus for, monitoring the radioactivity of a plurality of samples incorporating lower energy beta-emitting isotopes

    International Nuclear Information System (INIS)

    Warner, G.T.; Potter, C.G.

    1981-01-01

    A method for monitoring the radioactivity of a number of samples incorporating low energy beta-emitting isotopes which allows the simultaneous precipitation of many samples with a minimum of sample handling, is described. The samples are placed on a support so that they are not overlapping, the support and sample are permeated with liquid or gel scintillant and the sample areas are scanned. (U.K.)

  2. Humid scraping method to obtain samples for the analysis of D2 incorporated in the pressure tubes of Embalse Nuclear Power Plant

    International Nuclear Information System (INIS)

    Binetti, Edgardo O.; Cerutti, Carlos R.

    1999-01-01

    From ten fuel channels of the CNE reactor four samples of each channel were taken by means of the Humid Scraping method in order to evaluate the equivalent hydrogen content by incorporating deuterium in the pressure tubes. With these data, it is possible to make a list of priorities of channels for future replacement of spacer rings between pressure and calandria tubes, using Slarette equipment. (author)

  3. Analytical methods for the characterization of surface finishing in bricks

    International Nuclear Information System (INIS)

    Nardini, I.; Zendri, E.; Biscontin, G.; Brunetin, A.

    2006-01-01

    The recent restoration works of Santo Stefano Church Facade (XV century) in Venice have shown traces variously saved of different kind of surface finishes. These finishes were found on the brick's surface both in the masonry and in the decorative elements. Different brick's surface and decorative tile samples were investigated using several techniques: optical microscopy, scanning electron-microscopy, thermal analysis, infrared spectroscopy and reflectance Fourier transform infrared microspectroscopy. The evaluation of the reached results was used to understand the decorative techniques and to recognize the material employed

  4. Carbon nanotube oscillator surface profiling device and method of use

    Science.gov (United States)

    Popescu, Adrian [Tampa, FL; Woods, Lilia M [Tampa, FL; Bondarev, Igor V [Fuquay Varina, NC

    2011-11-15

    The proposed device is based on a carbon nanotube oscillator consisting of a finite length outer stationary nanotube and a finite length inner oscillating nanotube. Its main function is to measure changes in the characteristics of the motion of the carbon nanotube oscillating near a sample surface, and profile the roughness of this surface. The device operates in a non-contact mode, thus it can be virtually non-wear and non-fatigued system. It is an alternative to the existing atomic force microscope (AFM) tips used to scan surfaces to determine their roughness.

  5. Contribution of surface analysis spectroscopic methods to the lubrication field

    International Nuclear Information System (INIS)

    Blanc, C.

    1979-01-01

    The analytical surface technics such as ESCA, AES and SIMS are tested to be applied to a particular lubrication field. One deals with a 100 C 6 steel surface innumered in tricresylphosphate at 110 0 C for 15 days. The nature of the first layers is studied after relevant solvant cleaning. An iron oxide layer is produced on the bearing surface, namely αFe 2 -O 3 . ESCA, AES and SIMS studies show an overlayer of iron phosphate. The exact nature of iron phosphate is not clearly established but the formation of a ferrous phosphate coating can be assumed from ESCA analysis [fr

  6. Pentavalent Bismuth-Mediated Glycosylation Methods to Activate Sialic and Uronic Acids and the Incorporation of Sialic Acids Into Insulin

    Science.gov (United States)

    Kabotso, Daniel Elorm Kwame

    The negative charge at physiological pH of carboxylic acid-containing monosaccharides modulate the properties of many natural biomolecules such as oligosaccharides and glycoconjugates. Unfortunately, these altered electronic properties also make the incorporation of such acidic sugars more challenging as compared to the more commonly studied neutral sugars. Herein are reported the first demonstration of glycosylation reactions mediated by triphenylbis(1,1,1-trifluoromethanesulfonato)-bismuth with thioglycosides containing carboxylic acid substituents protected as esters. Unlike with many neutral sugar substrates, the addition of 1-propanethiol to the reactions proved critical to obtaining good yields of the desired glycosylation products using sialic acid, galacturonic acid, and glucuronic acid. The protocol was demonstrated to be amenable to automation using a liquid-handling platform. The consequences of artificially incorporating carboxylic-acid-containing sugars into proteins were tested by the design of a linker containing 1 to 4 sialic acids--a sugar found in many human proteins and brain tissues--that was attached via reductive amination of trityl thiopropylaldehyde at the phenyl alanine terminal end of the protein insulin produced through solid-phase peptide synthesis. Removal of the trityl group with neat trifluoroacetic acid furnished the thiol-free modified insulin that was ligated via a disulfide bond to the peptide scaffold bearing acetyl protected sialic acids. A 14-15% ammonium hydroxide solution was found to be effective in deprotecting the acetyl groups without degradation of the disulfide bond. In addition to maintaining the potency and bioactivity of insulin, the sialic acid-containing linker rendered insulin more resistant to aggregation due to heat and mechanical agitation compared to the unmodified protein.

  7. Method and coating composition for protecting and decontaminating surfaces

    Science.gov (United States)

    Overhold, D C; Peterson, M D

    1959-03-10

    A protective coating useful in the decontamination of surfaces exposed to radioactive substances is described. This coating is placed on the surface before use and is soluble in water, allowing its easy removal in the event decontamination becomes necessary. Suitable coating compositions may be prepared by mixing a water soluble carbohydrate such as sucrose or dextrin, together with a hygroscopic agent such as calcium chloride or zinc chloride.

  8. Influence of various surface-conditioning methods on the bond strength of metal brackets to ceramic surfaces

    NARCIS (Netherlands)

    Schmage, P; Nergiz, [No Value; Herrmann, W; Ozcan, M; Nergiz, Ibrahim; �zcan, Mutlu

    With the increase in adult orthodontic treatment comes the need to find a reliable method for bonding orthodontic brackets onto metal or ceramic crowns and fixed partial dentures. In this study, shear bond strength and surface roughness tests were used to examine the effect of 4 different surface

  9. Feasibility of using a seismic surface wave method to study seasonal and weather effects on shallow surface soils

    Science.gov (United States)

    The objective of this paper is to study the feasibility of using a seismic surface wave method to investigate seasonal and weather effects on shallow surface soils. In the study, temporal variations of subsurface soil properties were measured and monitored by using a combination of a new seismic su...

  10. Group IV nanocrystals with ion-exchangeable surface ligands and methods of making the same

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, Lance M.; Nichols, Asa W.; Chernomordik, Boris D.; Anderson, Nicholas C.; Beard, Matthew C.; Neale, Nathan R.

    2018-01-09

    Methods are described that include reacting a starting nanocrystal that includes a starting nanocrystal core and a covalently bound surface species to create an ion-exchangeable (IE) nanocrystal that includes a surface charge and a first ion-exchangeable (IE) surface ligand ionically bound to the surface charge, where the starting nanocrystal core includes a group IV element.

  11. A novel surface cleaning method for chemical removal of fouling lead layer from chromium surfaces

    Science.gov (United States)

    Gholivand, Kh.; Khosravi, M.; Hosseini, S. G.; Fathollahi, M.

    2010-10-01

    Most products especially metallic surfaces require cleaning treatment to remove surface contaminations that remain after processing or usage. Lead fouling is a general problem which arises from lead fouling on the chromium surfaces of bores and other interior parts of systems which have interaction with metallic lead in high temperatures and pressures. In this study, a novel chemical solution was introduced as a cleaner reagent for removing metallic lead pollution, as a fouling metal, from chromium surfaces. The cleaner aqueous solution contains hydrogen peroxide (H 2O 2) as oxidizing agent of lead layer on the chromium surface and acetic acid (CH 3COOH) as chelating agent of lead ions. The effect of some experimental parameters such as acetic acid concentration, hydrogen peroxide concentration and temperature of the cleaner solution during the operation on the efficiency of lead cleaning procedure was investigated. The results of scanning electron microscopy (SEM) showed that using this procedure, the lead pollution layer could be completely removed from real chromium surfaces without corrosion of the original surface. Finally, the optimum conditions for the complete and fast removing of lead pollution layer from chromium surfaces were proposed. The experimental results showed that at the optimum condition (acetic acid concentration 28% (V/V), hydrogen peroxide 8% (V/V) and temperature 35 °C), only 15-min time is needed for complete removal of 3 g fouling lead from a chromium surface.

  12. A biomarker panel (Bioscore incorporating monocytic surface and soluble TREM-1 has high discriminative value for ventilator-associated pneumonia: a prospective observational study.

    Directory of Open Access Journals (Sweden)

    Vimal Grover

    Full Text Available Ventilator-associated pneumonia (VAP increases mortality in critical illness. However, clinical diagnostic uncertainty persists. We hypothesised that measuring cell-surface and soluble inflammatory markers, incorporating Triggering Receptor Expressed by Myeloid cells (TREM-1, would improve diagnostic accuracy.A single centre prospective observational study, set in a University Hospital medical-surgical intensive Care unit, recruited 91 patients into 3 groups: 27 patients with VAP, 33 ventilated controls without evidence of pulmonary sepsis (non-VAP, and 31 non-ventilated controls (NVC, without clinical infection, attending for bronchoscopy. Paired samples of Bronchiolo-alveolar lavage fluid (BALF and blood from each subject were analysed for putative biomarkers of infection: Cellular (TREM-1, CD11b and CD62L and soluble (IL-1β, IL-6, IL-8, sTREM-1, Procalcitonin. Expression of cellular markers on monocytes and neutrophils were measured by flow cytometry. Soluble inflammatory markers were determined by ELISA. A biomarker panel ('Bioscore', was constructed, tested and validated, using Fisher's discriminant function analysis, to assess its value in distinguishing VAP from non VAP.The expression of TREM-1 on monocytes (mTREM-1 and neutrophils (nTREM-1 and concentrations of IL-1β, IL-8, and sTREM-1 in BALF were significantly higher in VAP compared with non-VAP and NVC (p<0.001. The BALF/blood mTREM-1 was significantly higher in VAP patients compared to non-VAP and NVC (0.8 v 0.4 v 0.3 p<0.001. A seven marker Bioscore (BALF/blood ratio mTREM-1 and mCD11b, BALF sTREM-1, IL-8 and IL-1β, and serum CRP and IL-6 correctly identified 88.9% of VAP cases and 100% of non-VAP cases.A 7-marker bioscore, incorporating cellular and soluble TREM-1, accurately discriminates VAP from non-pulmonary infection.

  13. Reducing Motional Decoherence in Ion Traps with Surface Science Methods

    Science.gov (United States)

    Haeffner, Hartmut

    2014-03-01

    Many trapped ions experiments ask for low motional heating rates while trapping the ions close to trapping electrodes. However, in practice small ion-electrode distances lead to unexpected high heating rates. While the mechanisms for the heating is still unclear, it is now evident that surface contamination of the metallic electrodes is at least partially responsible for the elevated heating rates. I will discuss heating rate measurements in a microfabricated surface trap complemented with basic surface science studies. We monitor the elemental surface composition of the Cu-Al alloy trap with an Auger spectrometer. After bake-out, we find a strong Carbon and Oxygen contamination and heating rates of 200 quanta/s at 1 MHz trap frequency. After removing most of the Carbon and Oxygen with Ar-Ion sputtering, the heating rates drop to 4 quanta/s. Interestingly, we still measure the decreased heating rate even after the surface oxidized from the background gas throughout a 40-day waiting time in UHV.

  14. Biomimetic superhydrophobic polyolefin surfaces fabricated with a facile scraping, bonding and peeling method

    NARCIS (Netherlands)

    Feng, Huanhuan; Zheng, Tingting; Wang, Huiliang

    2016-01-01

    Inspired by the superhydrophobicity of juicy peach surface, on which microscale hairs are standing vertically to the surface plane, an extremely simple, inexpensive physical method is developed for fabrication of superhydrophobic polyolefin surfaces over large areas. This method includes three

  15. Method of removing hazardous material deposited on concrete surface

    International Nuclear Information System (INIS)

    Komatsu, Fumiaki; Baba, Kyoji.

    1991-01-01

    A salt compound containing a carbonate group such as sodium carbonate or potassium carbonate is dissolved in water and the aqueous solution is sprayed on the surface of concretes, kept for a predetermined period and dried to deposit the carbonate on the surface of the concretes. Then, aqueous solution of an organic acid such as oxalic acid or citric acid is sprayed and reacted with the carbonate to form bubbles of gaseous carbon dioxide. With such procedures, hazardous material containing radioactive materials intruded to the unevenness or fine holes on the surface of the concrete, or heavy metals such as hexavalent chromium or lead are deposited to the bubbles of gaseous carbon dioxide to be raised up therewith. By removing the bubbles, hazardous materials such as radioactive materials or heavy metals intruded to the concretes can be removed without generating powdery dusts, without requiring a large-scaled device and without changing the characteristic of the concretes. (T.M.)

  16. Incorporating Meaningful Gamification in a Blended Learning Research Methods Class: Examining Student Learning, Engagement, and Affective Outcomes

    Science.gov (United States)

    Tan, Meng; Hew, Khe Foon

    2016-01-01

    In this study, we investigated how the use of meaningful gamification affects student learning, engagement, and affective outcomes in a short, 3-day blended learning research methods class using a combination of experimental and qualitative research methods. Twenty-two postgraduates were randomly split into two groups taught by the same…

  17. Methods of remote surface chemical analysis for asteroid missions

    International Nuclear Information System (INIS)

    Sagdeev, R.Z.; Managadze, G.G.; Shutyaev, I.Yu.; Timofeev, P.P.; Szegoe, K.

    1984-06-01

    Different remote sensing methods are discussed which can be applied to investigate the chemical composition of minor bodies of the Solar System. The secondary-ion method, remote laser mass-analysis and electron beam induced X-ray emission analysis are treated in detail. Relative advantages of these techniques are analyzed. The physical limitation of the methods: effects of solar magnetic field and solar wind on the secondary-ion and laser methods and the effect of electrostatic potential of the space apparatus on the ion and electron beam methods are described. First laboratory results of remote laser method are given. (D.Gy.)

  18. A surface refractive index scanning system and method

    DEFF Research Database (Denmark)

    2015-01-01

    The invention relates to a surface refractive index scanning system for characterization of a sample. The system comprises a grating device for holding or receiving the sample, the device comprising at least a first grating region having a first grating width along a transverse direction, and a s......The invention relates to a surface refractive index scanning system for characterization of a sample. The system comprises a grating device for holding or receiving the sample, the device comprising at least a first grating region having a first grating width along a transverse direction...

  19. Application of the Taguchi Method for Optimizing the Process Parameters of Producing Lightweight Aggregates by Incorporating Tile Grinding Sludge with Reservoir Sediments.

    Science.gov (United States)

    Chen, How-Ji; Chang, Sheng-Nan; Tang, Chao-Wei

    2017-11-10

    This study aimed to apply the Taguchi optimization technique to determine the process conditions for producing synthetic lightweight aggregate (LWA) by incorporating tile grinding sludge powder with reservoir sediments. An orthogonal array L 16 (4⁵) was adopted, which consisted of five controllable four-level factors (i.e., sludge content, preheat temperature, preheat time, sintering temperature, and sintering time). Moreover, the analysis of variance method was used to explore the effects of the experimental factors on the particle density, water absorption, bloating ratio, and loss on ignition of the produced LWA. Overall, the produced aggregates had particle densities ranging from 0.43 to 2.1 g/cm³ and water absorption ranging from 0.6% to 13.4%. These values are comparable to the requirements for ordinary and high-performance LWAs. The results indicated that it is considerably feasible to produce high-performance LWA by incorporating tile grinding sludge with reservoir sediments.

  20. A storm-based CSLE incorporating the modified SCS-CN method for soil loss prediction on the Chinese Loess Plateau

    Science.gov (United States)

    Shi, Wenhai; Huang, Mingbin

    2017-04-01

    the storm-based CSLE. In addition, the surface runoff used by the storm-based CSLE was either obtained from measurements or from the values predicted by the modified Soil Conservation Service Curve Number (SCS-CN) method. When using the measured runoff, the storm-based CSLE had an E of 76.6%, whereas the use of the predicted runoff gave an E of 76.4%. The high E values indicated that the storm-based CSLE incorporating the modified SCS-CN method could accurately predict storm-event-based soil losses resulting from both sheet and rill erosion at the field scale on the Chinese Loess Plateau. This approach could be applicable to other areas of the world once the model parameters have been suitably calibrated.

  1. Response surface method applied to optimization of estradiol ...

    Indian Academy of Sciences (India)

    An optimization process based on response surface methodology was carried out in order to develop a statistical model which describes the relationship between active independent variables and estradiol flux. This model can be used to find out a combination of factor levels during response optimization. Possible options ...

  2. Membrane mimetic surface functionalization of nanoparticles: Methods and applications

    Science.gov (United States)

    Weingart, Jacob; Vabbilisetty, Pratima; Sun, Xue-Long

    2013-01-01

    Nanoparticles (NPs), due to their size-dependent physical and chemical properties, have shown remarkable potential for a wide range of applications over the past decades. Particularly, the biological compatibilities and functions of NPs have been extensively studied for expanding their potential in areas of biomedical application such as bioimaging, biosensing, and drug delivery. In doing so, surface functionalization of NPs by introducing synthetic ligands and/or natural biomolecules has become a critical component in regards to the overall performance of the NP system for its intended use. Among known examples of surface functionalization, the construction of an artificial cell membrane structure, based on phospholipids, has proven effective in enhancing biocompatibility and has become a viable alternative to more traditional modifications, such as direct polymer conjugation. Furthermore, certain bioactive molecules can be immobilized onto the surface of phospholipid platforms to generate displays more reminiscent of cellular surface components. Thus, NPs with membrane-mimetic displays have found use in a range of bioimaging, biosensing, and drug delivery applications. This review herein describes recent advances in the preparations and characterization of integrated functional NPs covered by artificial cell membrane structures and their use in various biomedical applications. PMID:23688632

  3. Ion implantation method for preparing polymers having oxygen erosion resistant surfaces

    Science.gov (United States)

    Lee, Eal H.; Mansur, Louis K.; Heatherly, Jr., Lee

    1995-01-01

    Hard surfaced polymers and the method for making them are generally described. Polymers are subjected to simultaneous multiple ion beam bombardment, that results in a hardening of the surface, improved wear resistance, and improved oxygen erosion resistance.

  4. A surface defects inspection method based on multidirectional gray-level fluctuation

    Directory of Open Access Journals (Sweden)

    Yunpeng Ma

    2017-05-01

    Full Text Available Machine vision inspection technology provides an efficient tool for surface defects inspection. However, because of the multiformity of surface defects, the existing machine vision methods for surface defects inspection are limited by application scenarios. In order to improve the versatility of algorithms, and to process various kinds of images more accurately, we propose a new adaptive method for surface defect detection, named neighborhood gray-level difference method using the multidirectional gray-level fluctuation. This method changes thresholds and step values by extracting gray-level-fluctuating condition of images, and then it uses the neighborhood gray-level difference to segment defects from background. Experimental results demonstrate the effectiveness of the proposed method for inspecting different surface defects. Compared with other methods, the proposed method can be applied to inspect various surface defects, and it can provide more accurate defect segmentation results.

  5. Dynamic mapping of conical intersection seams: A general method for incorporating the geometric phase in adiabatic dynamics in polyatomic systems.

    Science.gov (United States)

    Xie, Changjian; Malbon, Christopher L; Yarkony, David R; Guo, Hua

    2017-07-28

    The incorporation of the geometric phase in single-state adiabatic dynamics near a conical intersection (CI) seam has so far been restricted to molecular systems with high symmetry or simple model Hamiltonians. This is due to the fact that the ab initio determined derivative coupling (DC) in a multi-dimensional space is not curl-free, thus making its line integral path dependent. In a recent work [C. L. Malbon et al., J. Chem. Phys. 145, 234111 (2016)], we proposed a new and general approach based on an ab initio determined diabatic representation consisting of only two electronic states, in which the DC is completely removable, so that its line integral is path independent in the simply connected domains that exclude the CI seam. Then with the CIs included, the line integral of the single-valued DC can be used to construct the complex geometry-dependent phase needed to exactly eliminate the double-valued character of the real-valued adiabatic electronic wavefunction. This geometry-dependent phase gives rise to a vector potential which, when included in the adiabatic representation, rigorously accounts for the geometric phase in a system with an arbitrary locus of the CI seam and an arbitrary number of internal coordinates. In this work, we demonstrate this approach in a three-dimensional treatment of the tunneling facilitated dissociation of the S 1 state of phenol, which is affected by a C s symmetry allowed but otherwise accidental seam of CI. Here, since the space is three-dimensional rather than two-dimensional, the seam is a curve rather than a point. The nodal structure of the ground state vibronic wavefunction is shown to map out the seam of CI.

  6. First-principles Green's-function method for surface calculations: A pseudopotential localized basis set approach

    Science.gov (United States)

    Smidstrup, Søren; Stradi, Daniele; Wellendorff, Jess; Khomyakov, Petr A.; Vej-Hansen, Ulrik G.; Lee, Maeng-Eun; Ghosh, Tushar; Jónsson, Elvar; Jónsson, Hannes; Stokbro, Kurt

    2017-11-01

    We present an efficient implementation of a surface Green's-function method for atomistic modeling of surfaces within the framework of density functional theory using a pseudopotential localized basis set approach. In this method, the system is described as a truly semi-infinite solid with a surface region coupled to an electron reservoir, thereby overcoming several fundamental drawbacks of the traditional slab approach. The versatility of the method is demonstrated with several applications to surface physics and chemistry problems that are inherently difficult to address properly with the slab method, including metal work function calculations, band alignment in thin-film semiconductor heterostructures, surface states in metals and topological insulators, and surfaces in external electrical fields. Results obtained with the surface Green's-function method are compared to experimental measurements and slab calculations to demonstrate the accuracy of the approach.

  7. Incorporation of exact boundary conditions into a discontinuous galerkin finite element method for accurately solving 2d time-dependent maxwell equations

    KAUST Repository

    Sirenko, Kostyantyn

    2013-01-01

    A scheme that discretizes exact absorbing boundary conditions (EACs) to incorporate them into a time-domain discontinuous Galerkin finite element method (TD-DG-FEM) is described. The proposed TD-DG-FEM with EACs is used for accurately characterizing transient electromagnetic wave interactions on two-dimensional waveguides. Numerical results demonstrate the proposed method\\'s superiority over the TD-DG-FEM that employs approximate boundary conditions and perfectly matched layers. Additionally, it is shown that the proposed method can produce the solution with ten-eleven digit accuracy when high-order spatial basis functions are used to discretize the Maxwell equations as well as the EACs. © 1963-2012 IEEE.

  8. The orthogonal gradients method: A radial basis functions method for solving partial differential equations on arbitrary surfaces

    KAUST Repository

    Piret, Cécile

    2012-05-01

    Much work has been done on reconstructing arbitrary surfaces using the radial basis function (RBF) method, but one can hardly find any work done on the use of RBFs to solve partial differential equations (PDEs) on arbitrary surfaces. In this paper, we investigate methods to solve PDEs on arbitrary stationary surfaces embedded in . R3 using the RBF method. We present three RBF-based methods that easily discretize surface differential operators. We take advantage of the meshfree character of RBFs, which give us a high accuracy and the flexibility to represent the most complex geometries in any dimension. Two out of the three methods, which we call the orthogonal gradients (OGr) methods are the result of our work and are hereby presented for the first time. © 2012 Elsevier Inc.

  9. Ion Beam Methods for the Surface Characterization of Polymers.

    Science.gov (United States)

    1982-02-01

    These surface spectroscopies are useful in many areas of polymer technology including synthesis, extrusion and forming, and long time durability and...Pure and Applied Chemistry Meeting on Polymer Degradation held at Durham University, Durham, England, in July 1981. The author thanks Dr. W. J. Feast...25 7 SIMS Data in Mass Range 160-330 from Teflon Using Charge Neutralization (Ref. 19) 26 8 (a) ISS/SIMS Data for Polypropylene Using 3He+ at 2500 eV

  10. Methods of Attaching or Grafting Carbon Nanotubes to Silicon Surfaces and Composite Structures Derived Therefrom

    Science.gov (United States)

    Tour, James M. (Inventor); Chen, Bo (Inventor); Flatt, Austen K. (Inventor); Stewart, Michael P. (Inventor); Dyke, Christopher A. (Inventor); Maya, Francisco (Inventor)

    2012-01-01

    The present invention is directed toward methods of attaching or grafting carbon nanotubes (CNTs) to silicon surfaces. In some embodiments, such attaching or grafting occurs via functional groups on either or both of the CNTs and silicon surface. In some embodiments, the methods of the present invention include: (1) reacting a silicon surface with a functionalizing agent (such as oligo(phenylene ethynylene)) to form a functionalized silicon surface; (2) dispersing a quantity of CNTs in a solvent to form dispersed CNTs; and (3) reacting the functionalized silicon surface with the dispersed CNTs. The present invention is also directed to the novel compositions produced by such methods.

  11. A Mixed Methods Evaluation of a 12-Week Insurance-Sponsored Weight Management Program Incorporating Cognitive-Behavioral Counseling

    Science.gov (United States)

    Abildso, Christiaan; Zizzi, Sam; Gilleland, Diana; Thomas, James; Bonner, Daniel

    2010-01-01

    Physical activity is critical in healthy weight loss, yet there is still much to be learned about psychosocial mechanisms of physical activity behavior change in weight loss. A sequential mixed methods approach was used to assess the physical and psychosocial impact of a 12-week cognitive-behavioral weight management program and explore factors…

  12. Review of Electrical and Gravity Methods of Near-Surface ...

    African Journals Online (AJOL)

    The theory and practice of electrical and gravity methods of geophysics for groundwater exploration was reviewed with illustrations and data examples. With the goal of reducing cases of borehole/water-well failure attributed to the lack of the knowledge of the methods of geophysics for groundwater exploration and ...

  13. Review of Electrical and Gravity Methods of Near-Surface ...

    African Journals Online (AJOL)

    USER

    method of groundwater exploration was discussed with field data from Wokbedilo community in Ethopia. ... Electromagnetic and electrical methods have shown superior suitability for groundwater exploration because rock properties that are crucial to hydrogeology ..... Where M and R are the mass and radius of the earth.

  14. Photoswitchable method for the ordered attachment of proteins to surfaces

    Science.gov (United States)

    Camarero, Julio A.; De Yoreo, James J.; Kwon, Youngeun

    2010-04-20

    Described herein is a method for the attachment of proteins to any solid support with control over the orientation of the attachment. The method is extremely efficient, not requiring the previous purification of the protein to be attached, and can be activated by UV-light. Spatially addressable arrays of multiple protein components can be generated by using standard photolithographic techniques.

  15. Ernst Equation and Riemann Surfaces: Analytical and Numerical Methods

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Frederick J [FJE Enterprises, 511 County Route 59, Potsdam, NY 13676 (United States)

    2007-06-18

    source can be represented by discontinuities in the metric tensor components. The first two chapters of this book are devoted to some basic ideas: in the introductory chapter 1 the authors discuss the concept of integrability, comparing the integrability of the vacuum Ernst equation with the integrability of nonlinear equations of Korteweg-de Vries (KdV) type, while in chapter 2 they describe various circumstances in which the vacuum Ernst equation has been determined to be relevant, not only in connection with gravitation but also, for example, in the construction of solutions of the self-dual Yang-Mills equations. It is also in this chapter that one of several equivalent linear systems for the Ernst equation is described. The next two chapters are devoted to Dmitry Korotkin's concept of algebro-geometric solutions of a linear system: in chapter 3 the structure of such solutions of the vacuum Ernst equation, which involve Riemann theta functions of hyperelliptic algebraic curves of any genus, is contrasted with the periodic structure of such solutions of the KdV equation. How such solutions can be obtained, for example, by solving a matrix Riemann-Hilbert problem and how the metric tensor of the associated spacetime can be evaluated is described in detail. In chapter 4 the asymptotic behaviour and the similarity structure of the general algebro-geometric solutions of the Ernst equation are described, and the relationship of such solutions to the perhaps more familiar multi-soliton solutions is discussed. The next three chapters are based upon the authors' own published research: in chapter 5 it is shown that a problem involving counter-rotating infinitely thin disks of matter can be solved in terms of genus two Riemann theta functions, while in chapter 6 the authors describe numerical methods that facilitate the construction of such solutions, and in chapter 7 three-dimensional graphs are displayed that depict all metrical fields of the associated spacetime

  16. The development of thermal nanoprobe methods as a means of characterizing and mapping plasticizer incorporation into ethylcellulose films.

    Science.gov (United States)

    Meng, Jin; Levina, Marina; Rajabi-Siahboomi, Ali R; Round, Andrew N; Reading, Mike; Craig, Duncan Q M

    2012-08-01

    The phase composition and distribution of ethylcellulose (EC) films containing varying amounts of the plasticizer fractionated coconut oil (FCO) were studied using a novel combination of thermal and mapping approaches. The thermal and thermomechanical properties of films containing up to 30% FCO were characterized using modulated temperature differential scanning calorimetry (MTDSC) and dynamic mechanical analysis (DMA). Film surfaces were mapped using atomic force microscopy (AFM; topographic and pulsed force modes) and the composition of specific regions identified using nanothermal probes. Clear evidence of distinct conjugate phases was obtained for the 20-30% FCO/EC film systems. We suggest a model whereby the composition of the distinct phases may be estimated via consideration of the glass transition temperatures observed using DSC and DMA. By combining pulsed force AFM and nano-thermal analysis we demonstrate that it is possible to map the two separated phases. In particular, the use of thermal probes allowed identification of the distinct regions via localized thermomechanical analysis, whereby nanoscale probe penetration is measured as a function of temperature. The study has indicated that by using thermal and imaging techniques in conjunction it is possible to both identify and map distinct regions in binary films.

  17. Integral methods for shallow free-surface flows with separation

    DEFF Research Database (Denmark)

    Watanabe, S.; Putkaradze, V.; Bohr, Tomas

    2003-01-01

    an inclined plane we take a similar approach and derive a simple model in which the velocity profile is not restricted to a parabolic or self-similar form. Two types of solutions with large surface distortions are found: solitary, kink-like propagating fronts, obtained when the flow rate is suddenly changed......, and stationary jumps, obtained, for instance, behind a sluice gate. We then include time dependence in the model to study the stability of these waves. This allows us to distinguish between sub- and supercritical flows by calculating dispersion relations for wavelengths of the order of the width of the layer....

  18. A new method for background rejection with surface sensitive bolometers

    International Nuclear Information System (INIS)

    Nones, C.; Foggetta, L.; Giuliani, A.; Pedretti, M.; Salvioni, C.; Sangiorgio, S.

    2006-01-01

    We report the performance of three prototype TeO 2 macrobolometers, able to identify events due to energy deposited at the detector surface. This capability is obtained by thermally coupling thin active layers to the main absorber of the bolometer, and is proved by irradiating the detectors with alpha particles. This technique can be very useful in view of background study and reduction for the CUORE experiment, a next generation Double Beta Decay search based on TeO 2 macrobolometers and to be installed in the Laboratori Nazionali del Gran Sasso

  19. Using of the surface activation method for enhancement of machine realibility

    International Nuclear Information System (INIS)

    Postnikov, V.I.; Garbar, I.N.

    1979-01-01

    A surface activation method is described for controlling the wear of units and details, allowing one to measure the wear at continuous operation of the mechanism by any program. The main advantages of the surface activation method for the wear tests are shown. By means of that method it was possible to develop a simultaneous controlling conjugate detail wear, and a method of different-activity brands, as well as the method for repeated activation of details. Development of theory for the engineering and technology of engine wear control by the surface activation method allowed one to improve the efficiency and reduce the time of research in the field of friction and wear

  20. Advanced Bayesian Methods for Lunar Surface Navigation, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The key innovation of this project is the application of advanced Bayesian methods to integrate real-time dense stereo vision and high-speed optical flow with an...

  1. Advanced Bayesian Methods for Lunar Surface Navigation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The key innovation of this project will be the application of advanced Bayesian methods to integrate real-time dense stereo vision and high-speed optical flow with...

  2. NATURAL ANTIBIOFOULING AGENTS AS NEW CONTROL METHOD FOR PHOTOTROPHIC BIOFILMS DWELLING ON MONUMENTAL STONE SURFACES

    OpenAIRE

    Oana-Adriana CUZMAN; Mara CAMAITI; Barbara SACCHI; Piero TIANO

    2011-01-01

    Five natural antibiofoulants with terrestrial (capsaicine - CS, cinnamaldehyde - CI) and marine origin (zosteric acid - ZA, poly-alkylpyridinium salts - pAPS and Ceramium botryocarpum extract - CBE) have been selected and tested against phototrophic biofilm formation on the stone surfaces for their inhibitory properties. The antibiofouling agents (ABAs) were incorporated into two commercial silicone based coatings (Silres BS OH 100 - S and Silres BS 290 - W). In this work, phototrophic growth...

  3. Evaluation of chemical surface treatment methods for mitigation of PWSCC

    International Nuclear Information System (INIS)

    Dame, C.; Marks, C.; Olender, A.; Farias, J.

    2015-01-01

    As part of its mission to propose innovative and safe technologies to mitigate Primary Water Stress Corrosion Cracking (PWSCC) in Pressurized Water Reactors (PWR), EPRI recently initiated a program to evaluate potential new chemical surface treatments that might delay the occurrence of PWSCC such that no failure of components would be observed during their lifetime. Among the initial screening of more than thirty technologies, seven were selected for a more detailed review. The selected technologies were: nickel and nickel alloy plating, organic inhibitors, chromium-based inhibitors, silicon carbide, titanium-based inhibitors, rare earth metal (REM)-based inhibitors and encapsulation. The conclusions of the review of these technologies were that two of them were worth pursuing, titanium-based and REM-based inhibitors, and that evaluating the radiological consequences of injecting these products in the primary system, as well as assessing their efficacy to mitigate PWSCC, should be prioritized as the next required steps in qualification for implementation. (authors)

  4. Application of response surface methodology method in designing corrosion inhibitor

    Science.gov (United States)

    Asmara, Y. P.; Athirah; Siregar, J. P.; Kurniawan, T.; Bachtiar, D.

    2017-10-01

    In oil and gas pipelines and offshore structure, inhibitors have been considered to be the first choice to reduce corrosion rate. There are many corrosion inhibitor compositions available in the market. To produce the best corrosion inhibitor requires many experimental data which is not efficient. These experiments used response surface methodology (RSM) to select corrosion inhibitor compositions. The experiments investigated effects of corrosion inhibition on corrosion rate of low carbon steel in 3% NaCl solution with different concentrations of selected main inhibitor compositions which are ethyl acetate (EA), ethylene glycol (EG) and sodium benzoate (SB). Corrosion rate were calculated using linear polarization resistance (LPR). All of the experiments were set in natural conditions at pH 7. MINITAB® version 15 was used for data analysis. It is shown that a quadratic model is a representative model can predict best corrosion inhibitor composition comprehensibly.

  5. Mixture and method for simulating soiling and weathering of surfaces

    Science.gov (United States)

    Sleiman, Mohamad; Kirchstetter, Thomas; Destaillats, Hugo; Levinson, Ronnen; Berdahl, Paul; Akbari, Hashem

    2018-01-02

    This disclosure provides systems, methods, and apparatus related to simulated soiling and weathering of materials. In one aspect, a soiling mixture may include an aqueous suspension of various amounts of salt, soot, dust, and humic acid. In another aspect, a method may include weathering a sample of material in a first exposure of the sample to ultraviolet light, water vapor, and elevated temperatures, depositing a soiling mixture on the sample, and weathering the sample in a second exposure of the sample to ultraviolet light, water vapor, and elevated temperatures.

  6. Platinum incorporation in the Na Y zeolite through impregnation method, and characterization by XRD, FTIR and nitrogen adsorption

    International Nuclear Information System (INIS)

    Araujo, A.S.; Sousa, B.V.; Andrade, A.C.C.; Rodrigues, M.G.F.; Rangel, M.C.

    2007-01-01

    Supported metal catalysts are widely used in petroleum refining, chemical and petroleum industries. These catalysts are important in ammonia synthesis, conversion of hydrocarbons with water vapor to synthesis gas, reforming, hydrocracking, ... Platinum has long been used in cracking, hydrogenation and dehydrogenation processes. The aim of this project is the Na Y zeolitic sample preparation through impregnation for incipient humidity, with 0,5% concentration of platinum, aiming its use as a catalyst in the steam reforming reaction. The characterization techniques used were: X Rays Diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and Nitrogen Adsorption (BET Method). From the obtained results through the techniques mentioned previously it is possible to evidence that the platinum impregnation process did not change the Na Y zeolite structure. Through the superficial specific area (BET) it was possible to observe that the platinum impregnation process caused a decrease in the specific area due to the reduction to the accessibility to the micropores of the zeolitic structure. (author)

  7. A simple method to assess bacterial attachment to surfaces

    Digital Repository Service at National Institute of Oceanography (India)

    Sonak; Bhosle

    of ineubation. There was a highly significant positive linear relationship between crystal violet stained attached cells and the viable cell count of cells attached to aluminium panels (r = 0.9997; p less than 0.001: n = 6). The method is relatively simple...

  8. The calculation of surface free energy based on embedded atom method for solid nickel

    International Nuclear Information System (INIS)

    Luo Wenhua; Hu Wangyu; Su Kalin; Liu Fusheng

    2013-01-01

    Highlights: ► A new solution for accurate prediction of surface free energy based on embedded atom method was proposed. ► The temperature dependent anisotropic surface energy of solid nickel was obtained. ► In isotropic environment, the approach does not change most predictions of bulk material properties. - Abstract: Accurate prediction of surface free energy of crystalline metals is a challenging task. The theory calculations based on embedded atom method potentials often underestimate surface free energy of metals. With an analytical charge density correction to the argument of the embedding energy of embedded atom method, an approach to improve the prediction for surface free energy is presented. This approach is applied to calculate the temperature dependent anisotropic surface energy of bulk nickel and surface energies of nickel nanoparticles, and the obtained results are in good agreement with available experimental data.

  9. The modal surface interpolation method for damage localization

    Science.gov (United States)

    Pina Limongelli, Maria

    2017-05-01

    The Interpolation Method (IM) has been previously proposed and successfully applied for damage localization in plate like structures. The method is based on the detection of localized reductions of smoothness in the Operational Deformed Shapes (ODSs) of the structure. The IM can be applied to any type of structure provided the ODSs are estimated accurately in the original and in the damaged configurations. If the latter circumstance fails to occur, for example when the structure is subjected to an unknown input(s) or if the structural responses are strongly corrupted by noise, both false and missing alarms occur when the IM is applied to localize a concentrated damage. In order to overcome these drawbacks a modification of the method is herein investigated. An ODS is the deformed shape of a structure subjected to a harmonic excitation: at resonances the ODS are dominated by the relevant mode shapes. The effect of noise at resonance is usually lower with respect to other frequency values hence the relevant ODS are estimated with higher reliability. Several methods have been proposed to reliably estimate modal shapes in case of unknown input. These two circumstances can be exploited to improve the reliability of the IM. In order to reduce or eliminate the drawbacks related to the estimation of the ODSs in case of noisy signals, in this paper is investigated a modified version of the method based on a damage feature calculated considering the interpolation error relevant only to the modal shapes and not to all the operational shapes in the significant frequency range. Herein will be reported the comparison between the results of the IM in its actual version (with the interpolation error calculated summing up the contributions of all the operational shapes) and in the new proposed version (with the estimation of the interpolation error limited to the modal shapes).

  10. A quantitative method to estimate high gloss polished tool steel surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rebeggiani, S; Rosen, B-G [Halmstad University, The Functional Surfaces Research Group, Box 823, SE-301 18 HALMSTAD (Sweden); Sandberg, A, E-mail: sabina.rebeggiani@hh.se [Uddeholms AB, SE-683 85 Hagfors (Sweden)

    2011-08-19

    Visual estimations are today the most common way to assess the surface quality of moulds and dies; a method that are both subjective and, with today's high demands on surfaces, hardly usable to distinguish between the finest surface qualities. Instead a method based on non-contact 3D-surface texture analysis is suggested. Several types of tool steel samples, manually as well as machine polished, were analysed to study different types of surface defects such as pitting, orange peel and outwardly features. The classification of the defect structures serves as a catalogue where known defects are described. Suggestions of different levels of 'high surface quality' defined in numerical values adapted to high gloss polished tool steel surfaces are presented. The final goal is to develop a new manual that can work as a 'standard' for estimations of tool steel surfaces for steel producers, mould makers, polishers etc.

  11. Comparison of two methods of surface profile extraction from multiple ultrasonic range measurements

    NARCIS (Netherlands)

    Barshan, B; Baskent, D

    Two novel methods for surface profile extraction based on multiple ultrasonic range measurements are described and compared. One of the methods employs morphological processing techniques, whereas the other employs a spatial voting scheme followed by simple thresholding. Morphological processing

  12. Method of defence of solder surface from oxidization

    Directory of Open Access Journals (Sweden)

    Kurmashev Sh. D.

    2010-02-01

    Full Text Available Compositions are developed for defence of fusion solder from oxidization on the basis of mixture of glycerin, urea and powders of refractory oxides, carbides (Al2O3, TiO2, SIC, graphite. The offered compositions can be used for defence of fusion of solder from oxidization in the process of soludering and tinning of explorers, and also electric conclusions of elements of radio electronic apparatus by the method of immersion in stationary baths.

  13. Laparoscopy training in surgical education: the utility of incorporating a structured preclinical laparoscopy course into the traditional apprenticeship method.

    Science.gov (United States)

    De Win, Gunter; Van Bruwaene, Siska; Aggarwal, Rajesh; Crea, Nicola; Zhang, Zhewen; De Ridder, Dirk; Miserez, Marc

    2013-01-01

    To investigate whether preclinical laparoscopy training offers a benefit over standard apprenticeship training and apprenticeship training in combination with simulation training. This randomized controlled trial consisted of 3 groups of first-year surgical registrars receiving a different teaching method in laparoscopic surgery. The KU LEUVEN Faculty of Medicine is the largest medical faculty in Belgium. Thirty final-year medical students starting a general surgical career in the next academic year. Thirty final-year medical students were randomized into 3 groups, which differed in the way they were exposed to laparoscopic simulation training but were comparable in regard to ambidexterity, sex, age, and laparoscopic psychomotoric skills. The control group received only clinical training during surgical residentship, whereas the interval group received clinical training in combination with simulation training. The registrars were allowed to do deliberate practice. The Centre for Surgical Technologies Preclinical Training Programme (CST PTP) group received a preclinical simulation course during the final year as medical students, but was not exposed to any extra simulation training during surgical residentship. At the beginning of surgical residentship and 6 months later, all subjects performed a standardized suturing task and a laparoscopic cholecystectomy in a POP Trainer. All procedures were recorded together with time and motion tracking parameters. All videos were scored by a blinded observer using global rating scales. At baseline the 3 groups were comparable. At 6 months, for suturing, the CST PTP group was better than both the other groups with respect to time, checklist, and amount of movements. The interval group was better than the control group on only the time and checklist score. For the cholecystectomy evaluation, there was a statistical difference between the CST PTP study group and both other groups on all evaluation scales in favor of the CST PTP

  14. Soft-landing ion deposition of isolated radioactive probe atoms on surfaces: A novel method

    NARCIS (Netherlands)

    Laurens, C.R; Rosu, M.F; Pleiter, F; Niesen, L

    1997-01-01

    We present a method to deposit a wide range of radioactive probe atoms on surfaces, without introducing lattice damage or contaminating the surface with other elements or isotopes. In this method, the probe atoms are mass separated using an isotope separator, decelerated to 5 eV, and directly

  15. Air powder abrasive treatment as an implant surface cleaning method: a literature review

    NARCIS (Netherlands)

    Tastepe, C.S.; van Waas, R.; Liu, Y.; Wismeijer, D.

    2012-01-01

    OBJECTIVE: To evaluate the air powder abrasive treatment as an implant surface cleaning method for peri-implantitis based on the existing literature. MATERIALS AND METHODS: A PubMed search was conducted to find articles that reported on air powder abrasive treatment as an implant surface cleaning

  16. Determination of optimum "multi-channel surface wave method" field parameters.

    Science.gov (United States)

    2012-12-01

    Multi-channel surface wave methods (especially the multi-channel analyses of surface wave method; MASW) are routinely used to : determine the shear-wave velocity of the subsurface to depths of 100 feet for site classification purposes. Users are awar...

  17. Developments of a bonding technique for optical materials by a surface activation method

    International Nuclear Information System (INIS)

    Sugiyama, Akira; Oda, Tomohiro; Abe, Tomoyuki; Kusunoki, Isao

    2005-01-01

    We started developing the laser crystal bounding by the surface activation method which can splice crystals together without using hydrogen bonding. For the surface activation, neutral argon beams were used for irradiation of specimens. In the bonding trials with sapphire crystals, we recognized possibility of the bonding method for optical elements. (author)

  18. Method of electrode printing on one or more surfaces of a dielectric substrate

    KAUST Repository

    Neophytou, Marios

    2017-09-14

    Described herein is a method for printing electrodes surfaces of a dielectric substrate. Provided herein is a new method of depositing electrically conductive electrodes of any shape on flexible and/or rigid dielectric substrates/surfaces and devices so produced. In various embodiments, the devices can generate ionic wind, for example to remove dust or other debris or contaminants or to remove ice or humidity from a surface.

  19. A Level Set Discontinuous Galerkin Method for Free Surface Flows - and Water-Wave Modeling

    DEFF Research Database (Denmark)

    Grooss, Jesper

    2005-01-01

    We present a discontinuous Galerkin method on a fully unstructured grid for the modeling of unsteady incompressible fluid flows with free surfaces. The surface is modeled by a level set technique. We describe the discontinuous Galerkin method in general, and its application to the flow equations...... equations in time are discussed. We investigate theory of di erential algebraic equations, and connect the theory to current methods for solving the unsteady fluid flow equations. We explore the use of a semi-implicit spectral deferred correction method having potential to achieve high temporal order....... The deferred correction method is applied on the fluid flow equations and show good results in periodic domains. We describe the design of a level set method for the free surface modeling. The level set utilize the high order accurate discontinuous Galerkin method fully and represent smooth surfaces very...

  20. Using parallel computing methods to improve log surface defect detection methods

    Science.gov (United States)

    R. Edward Thomas; Liya. Thomas

    2013-01-01

    Determining the size and location of surface defects is crucial to evaluating the potential yield and value of hardwood logs. Recently a surface defect detection algorithm was developed using the Java language. This algorithm was developed around an earlier laser scanning system that had poor resolution along the length of the log (15 scan lines per foot). A newer...

  1. Importance of the carbon surface chemistry: methods of characterization; Importance de la chimie de surface des materiaux carbones

    Energy Technology Data Exchange (ETDEWEB)

    Burg, Ph. [Universite Paul Verlaine, Lab. de Chimie et Applications, UFR Sciences, 57 - Metz (France); Vix-Guterl, C. [Centre National de la Recherche Scientifique, Institut de Chimie des Surfaces et Interfaces (ICSI) UPR CNRS 9069, 68 - Mulhouse (France)

    2006-03-15

    The diversity of the carbonaceous materials in terms of chemical composition and porous texture explains their large field of applications. The performances of such materials are often influenced by their surface chemistry that is not easy to investigate. Thus a large range of complementary analytical methods is necessary. (authors)

  2. A robust real-time surface reconstruction method on point clouds captured from a 3D surface photogrammetry system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenyang [Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095 (United States); Cheung, Yam [Department of Radiation Oncology, University of Texas Southwestern, Dallas, Texas 75390 (United States); Sawant, Amit [Department of Radiation Oncology, University of Texas Southwestern, Dallas, Texas, 75390 and Department of Radiation Oncology, University of Maryland, College Park, Maryland 20742 (United States); Ruan, Dan, E-mail: druan@mednet.ucla.edu [Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095 and Department of Radiation Oncology, University of California, Los Angeles, Los Angeles, California 90095 (United States)

    2016-05-15

    Purpose: To develop a robust and real-time surface reconstruction method on point clouds captured from a 3D surface photogrammetry system. Methods: The authors have developed a robust and fast surface reconstruction method on point clouds acquired by the photogrammetry system, without explicitly solving the partial differential equation required by a typical variational approach. Taking advantage of the overcomplete nature of the acquired point clouds, their method solves and propagates a sparse linear relationship from the point cloud manifold to the surface manifold, assuming both manifolds share similar local geometry. With relatively consistent point cloud acquisitions, the authors propose a sparse regression (SR) model to directly approximate the target point cloud as a sparse linear combination from the training set, assuming that the point correspondences built by the iterative closest point (ICP) is reasonably accurate and have residual errors following a Gaussian distribution. To accommodate changing noise levels and/or presence of inconsistent occlusions during the acquisition, the authors further propose a modified sparse regression (MSR) model to model the potentially large and sparse error built by ICP with a Laplacian prior. The authors evaluated the proposed method on both clinical point clouds acquired under consistent acquisition conditions and on point clouds with inconsistent occlusions. The authors quantitatively evaluated the reconstruction performance with respect to root-mean-squared-error, by comparing its reconstruction results against that from the variational method. Results: On clinical point clouds, both the SR and MSR models have achieved sub-millimeter reconstruction accuracy and reduced the reconstruction time by two orders of magnitude to a subsecond reconstruction time. On point clouds with inconsistent occlusions, the MSR model has demonstrated its advantage in achieving consistent and robust performance despite the introduced

  3. Measurement of the specific surface area of loose copper deposit by electrochemical methods

    Directory of Open Access Journals (Sweden)

    E. A. Dolmatova

    2016-07-01

    Full Text Available In the work the surface area of the electrode with dispersed copper deposit obtained within 30 seconds was evaluated by techniques of chronopotentiometry (CPM and impedance spectroscopy. In method CPM the electrode surface available for measurement depends on the value of the polarizing current. At high currents during the transition time there is a change of surface relief that can not determine the full surface of loose deposit. The electrochemical impedance method is devoid of this shortcoming since the measurements are carried out in indifferent electrolyte in the absence of current. The area measured by the impedance is tens of times higher than the value obtained by chronopotentiometry. It is found that from a solution containing sulfuric acid the deposits form with a high specific surface area. Based on these data it was concluded that the method of impedance spectroscopy can be used to measure in situ the surface area of the dispersed copper deposits.

  4. Comparison of diffusion charging and mobility-based methods for measurement of aerosol agglomerate surface area.

    Science.gov (United States)

    Ku, Bon Ki; Kulkarni, Pramod

    2012-05-01

    We compare different approaches to measure surface area of aerosol agglomerates. The objective was to compare field methods, such as mobility and diffusion charging based approaches, with laboratory approach, such as Brunauer, Emmett, Teller (BET) method used for bulk powder samples. To allow intercomparison of various surface area measurements, we defined 'geometric surface area' of agglomerates (assuming agglomerates are made up of ideal spheres), and compared various surface area measurements to the geometric surface area. Four different approaches for measuring surface area of agglomerate particles in the size range of 60-350 nm were compared using (i) diffusion charging-based sensors from three different manufacturers, (ii) mobility diameter of an agglomerate, (iii) mobility diameter of an agglomerate assuming a linear chain morphology with uniform primary particle size, and (iv) surface area estimation based on tandem mobility-mass measurement and microscopy. Our results indicate that the tandem mobility-mass measurement, which can be applied directly to airborne particles unlike the BET method, agrees well with the BET method. It was also shown that the three diffusion charging-based surface area measurements of silver agglomerates were similar within a factor of 2 and were lower than those obtained from the tandem mobility-mass and microscopy method by a factor of 3-10 in the size range studied. Surface area estimated using the mobility diameter depended on the structure or morphology of the agglomerate with significant underestimation at high fractal dimensions approaching 3.

  5. Advantage Clean & Porous TM new technological methods of surface treatment of dental implants

    Directory of Open Access Journals (Sweden)

    Лев Ильич Винников

    2015-02-01

    Full Text Available The purpose of this study was a comparative analysis of the surfaces of dental implants treated with technological methods SLA and RBM to identify their positive and negative characteristics. Based on these results to develop a new process Clean & Porous surface treatment of dental implants to obtain highly, rough and porous surface, which is characteristic for the technology SLA, and absolutely clean surface characteristic of technology RBM, without their disadvantages (unwarranted complete removal of abrasive particles SLA case and the absence of a clear structure of the surface topography in the case of RBM.The structure and purity of the implant surface Straumann, Alfa-Bio, DIO, Finish Line. studied in micrographs obtained by an electron microscope (SEM at the University of Technion (increase 500,2000,3000. To study the chemical properties of the samples, the method of X-ray energy dispersive spectroscopy (EDS, based on an analysis of its X-ray emission energy spectrum.Comparative analysis of the implant surfaces treated with the methods and RBM SLA showed that despite the reliability of these methods, each of them has certain disadvantages (contamination cases alumina particle surface with sufficient structural SLA and craters on the surface organized RBM. Developed by Finish Line Materials and Processes Ltd new technology of surface treatment of dental implants Clean & PorousTM, combining the best characteristics of the methods of SLA and RBM, possible to obtain a well-structured and absolutely clean surface.The proposed new original method Clean & PorousTM treatment of dental implants meet the criteria (roughness, porosity and surface finish of the implant, which provide an ideal osseointegration. Since osseointegration is a key issue in modern implantology it enables to obtain reliable primary fixation of the implant in the bone. From a clinical point of view it reduces the healing of the implant, as well as creating conditions

  6. Safety and effectiveness of maxillary early loaded titanium implants with a novel nanostructured calcium-incorporated surface (Xpeed): 1-year results from a pilot multicenter randomised controlled trial.

    Science.gov (United States)

    Esposito, Marco; Grusovin, Maria Gabriella; Pellegrino, Gerardo; Soardi, Elisa; Felice, Pietro

    2012-01-01

    To evaluate clinical safety and effectiveness of a novel calcium-incorporated titanium implant (Xpeed, MegaGen Implant Co. Limited, Gyeongbuk, South Korea). Sixty patients were randomised to receive either 1 to 6 calcium-incorporated or control titanium implants in the maxilla according to a parallel group design at 2 different centres. Implants were submerged and exposed at 3 different endpoints in equal groups of 20 patients each at 12, 10 and 8 weeks, respectively. Within 2 weeks, implants were functionally loaded with provisional or definitive prostheses. Outcome measures were prosthesis failures, implant failures, any complications and peri-implant marginal bone level changes. Thirty patients received 45 calcium-incorporated implants and 30 patients received 42 control titanium implants. One year after loading, no drop-outs and no prosthesis or implant failures occurred. There were no statistically significant differences between groups for complications (P = 0.61; difference in proportions = -0.27; 95% CI -0.71 to 0.18) and mean marginal bone level changes (P = 0.64; mean difference -0.04 mm; 95% CI -0.22 to 0.13). Nanostructured calcium-incorporated titanium implants seem to be at least as effective and safe as conventional titanium implants.

  7. Method of driving liquid flow at or near the free surface using magnetic microparticles

    Science.gov (United States)

    Snezhko, Oleksiy [Woodridge, IL; Aronson, Igor [Darien, IL; Kwok, Wai-Kwong [Evanston, IL; Belkin, Maxim V [Woodridge, IL

    2011-10-11

    The present invention provides a method of driving liquid flow at or near a free surface using self-assembled structures composed of magnetic particles subjected to an external AC magnetic field. A plurality of magnetic particles are supported at or near a free surface of liquid by surface tension or buoyancy force. An AC magnetic field traverses the free surface and dipole-dipole interaction between particles produces in self-assembled snake structures which oscillate at the frequency of the traverse AC magnetic field. The snake structures independently move across the free surface and may merge with other snake structures or break up and coalesce into additional snake structures experiencing independent movement across the liquid surface. During this process, the snake structures produce asymmetric flow vortices across substantially the entirety of the free surface, effectuating liquid flow across the free surface.

  8. A robust real-time surface reconstruction method on point clouds captured from a 3D surface photogrammetry system.

    Science.gov (United States)

    Liu, Wenyang; Cheung, Yam; Sawant, Amit; Ruan, Dan

    2016-05-01

    To develop a robust and real-time surface reconstruction method on point clouds captured from a 3D surface photogrammetry system. The authors have developed a robust and fast surface reconstruction method on point clouds acquired by the photogrammetry system, without explicitly solving the partial differential equation required by a typical variational approach. Taking advantage of the overcomplete nature of the acquired point clouds, their method solves and propagates a sparse linear relationship from the point cloud manifold to the surface manifold, assuming both manifolds share similar local geometry. With relatively consistent point cloud acquisitions, the authors propose a sparse regression (SR) model to directly approximate the target point cloud as a sparse linear combination from the training set, assuming that the point correspondences built by the iterative closest point (ICP) is reasonably accurate and have residual errors following a Gaussian distribution. To accommodate changing noise levels and/or presence of inconsistent occlusions during the acquisition, the authors further propose a modified sparse regression (MSR) model to model the potentially large and sparse error built by ICP with a Laplacian prior. The authors evaluated the proposed method on both clinical point clouds acquired under consistent acquisition conditions and on point clouds with inconsistent occlusions. The authors quantitatively evaluated the reconstruction performance with respect to root-mean-squared-error, by comparing its reconstruction results against that from the variational method. On clinical point clouds, both the SR and MSR models have achieved sub-millimeter reconstruction accuracy and reduced the reconstruction time by two orders of magnitude to a subsecond reconstruction time. On point clouds with inconsistent occlusions, the MSR model has demonstrated its advantage in achieving consistent and robust performance despite the introduced occlusions. The authors have

  9. Micro Surface Defect Detection Method for Silicon Steel Strip Based on Saliency Convex Active Contour Model

    Directory of Open Access Journals (Sweden)

    Kechen Song

    2013-01-01

    Full Text Available Accurate detection of surface defect is an indispensable section in steel surface inspection system. In order to detect the micro surface defect of silicon steel strip, a new detection method based on saliency convex active contour model is proposed. In the proposed method, visual saliency extraction is employed to suppress the clutter background for the purpose of highlighting the potential objects. The extracted saliency map is then exploited as a feature, which is fused into a convex energy minimization function of local-based active contour. Meanwhile, a numerical minimization algorithm is introduced to separate the micro surface defects from cluttered background. Experimental results demonstrate that the proposed method presents good performance for detecting micro surface defects including spot-defect and steel-pit-defect. Even in the cluttered background, the proposed method detects almost all of the microdefects without any false objects.

  10. Comparison of 3 methods on fabricating micro- /nano- structured surface on 3D mold cavity

    DEFF Research Database (Denmark)

    Zhang, Yang; Hansen, Hans Nørgaard; Bissacco, Giuliano

    2015-01-01

    limited to flat or simple shaped geometries. In this paper, 3 approaches for fabricating micro and nano- structured surfaces on a mold cavity for injection moulding are investigated and compared. The first approach is to use pre-fabricated plate with micro-structured surface as an insert for the mold......The methods to manufacture micro- or nano- structures on surfaces have been an area of intense investigation. Demands are shown for technologies for surface structuring on real 3D parts in many fields. However, most technologies for the fabrication of micro-structured functional surfaces are still...

  11. Numerical simulation of sloshing with large deforming free surface by MPS-LES method

    Science.gov (United States)

    Pan, Xu-jie; Zhang, Huai-xin; Sun, Xue-yao

    2012-12-01

    Moving particle semi-implicit (MPS) method is a fully Lagrangian particle method which can easily solve problems with violent free surface. Although it has demonstrated its advantage in ocean engineering applications, it still has some defects to be improved. In this paper, MPS method is extended to the large eddy simulation (LES) by coupling with a sub-particle-scale (SPS) turbulence model. The SPS turbulence model turns into the Reynolds stress terms in the filtered momentum equation, and the Smagorinsky model is introduced to describe the Reynolds stress terms. Although MPS method has the advantage in the simulation of the free surface flow, a lot of non-free surface particles are treated as free surface particles in the original MPS model. In this paper, we use a new free surface tracing method and the key point is "neighbor particle". In this new method, the zone around each particle is divided into eight parts, and the particle will be treated as a free surface particle as long as there are no "neighbor particles" in any two parts of the zone. As the number density parameter judging method has a high efficiency for the free surface particles tracing, we combine it with the neighbor detected method. First, we select out the particles which may be mistreated with high probabilities by using the number density parameter judging method. And then we deal with these particles with the neighbor detected method. By doing this, the new mixed free surface tracing method can reduce the mistreatment problem efficiently. The serious pressure fluctuation is an obvious defect in MPS method, and therefore an area-time average technique is used in this paper to remove the pressure fluctuation with a quite good result. With these improvements, the modified MPS-LES method is applied to simulate liquid sloshing problems with large deforming free surface. Results show that the modified MPS-LES method can simulate the large deforming free surface easily. It can not only capture

  12. A DFT based method for calculating the surface energies of asymmetric MoP facets

    Science.gov (United States)

    Tian, Xinxin; Wang, Tao; Fan, Lifang; Wang, Yuekui; Lu, Haigang; Mu, Yuewen

    2018-01-01

    MoP is a promising catalyst in heterogeneous catalysis. Understanding its surface stability and morphology is the first and essential step in exploring its catalytic properties. However, traditional surface energy calculation method does not work for the asymmetric termination of MoP. In this work, we reported a useful DFT based method to get the surface energies of asymmetric MoP facets. Under ideal condition, the (101) surface with mixed Mo/P termination is most stable, followed by the (100) surface, while the (001) surface is least stable. Wulff construction reveals the exposure of six surfaces on the MoP nanoparticle, where the (101) has the largest contribution. Atomistic thermodynamics results reveal the changes in surface stability orders with experimental conditions, and the (001)-P termination becomes more and more stable with increasing P chemical potential, which indicates its exposure is possible at defined conditions. Our results agree well with the previous experimental XRD and TEM data. We believe the reported method for surface energy calculation could be extended to other similar systems with asymmetric surface terminations.

  13. “Having to Shift Everything We’ve Learned to the Side”: Expanding Research Methods Taught in Psychology to Incorporate Qualitative Methods

    Science.gov (United States)

    Roberts, Lynne D.; Castell, Emily

    2016-01-01

    In Australia the tradition of conducting quantitative psychological research within a positivist framework has been challenged, with calls made for the inclusion of the full range of qualitative and quantitative methodologies within the undergraduate psychology curriculum. Despite this, the undergraduate psychology curriculum in most Australian universities retains a strong focus on teaching quantitative research methods. Limited research has examined attitudes toward qualitative research held by undergraduate psychology students taught within a positivist framework, and whether these attitudes are malleable and can be changed through teaching qualitative methodologies. Previous research has suggested that students from strong quantitative backgrounds experience some cognitive dissonance and greater difficulties in learning qualitative methods. In this article we examine 3rd year undergraduate psychology students’ attitudes to qualitative research prior to commencing and upon completion of a qualitative research unit. All students had previously completed two 13 weeks units of study in quantitative research methods. At Time 1, 63 students (84.1% female) completed online surveys comprising attitudinal measures. Key themes to emerge from student comments were that qualitative research was seen as an alternative approach, representing a paradigmatic shift that was construed by some students advantageous for meeting future professional and educative goals. Quantitative measures of attitudes to qualitative research were associated with general attitudes toward research, and psychology-specific epistemological beliefs. Changes in attitudes following completion of the qualitative research methods unit were in the hypothesized direction, but non-significant (small effect sizes). The findings increase our understanding of psychology students’ attitudes toward qualitative research and inform our recommendations for teaching research methods within the undergraduate

  14. "Having to Shift Everything We've Learned to the Side": Expanding Research Methods Taught in Psychology to Incorporate Qualitative Methods.

    Science.gov (United States)

    Roberts, Lynne D; Castell, Emily

    2016-01-01

    In Australia the tradition of conducting quantitative psychological research within a positivist framework has been challenged, with calls made for the inclusion of the full range of qualitative and quantitative methodologies within the undergraduate psychology curriculum. Despite this, the undergraduate psychology curriculum in most Australian universities retains a strong focus on teaching quantitative research methods. Limited research has examined attitudes toward qualitative research held by undergraduate psychology students taught within a positivist framework, and whether these attitudes are malleable and can be changed through teaching qualitative methodologies. Previous research has suggested that students from strong quantitative backgrounds experience some cognitive dissonance and greater difficulties in learning qualitative methods. In this article we examine 3rd year undergraduate psychology students' attitudes to qualitative research prior to commencing and upon completion of a qualitative research unit. All students had previously completed two 13 weeks units of study in quantitative research methods. At Time 1, 63 students (84.1% female) completed online surveys comprising attitudinal measures. Key themes to emerge from student comments were that qualitative research was seen as an alternative approach, representing a paradigmatic shift that was construed by some students advantageous for meeting future professional and educative goals. Quantitative measures of attitudes to qualitative research were associated with general attitudes toward research, and psychology-specific epistemological beliefs. Changes in attitudes following completion of the qualitative research methods unit were in the hypothesized direction, but non-significant (small effect sizes). The findings increase our understanding of psychology students' attitudes toward qualitative research and inform our recommendations for teaching research methods within the undergraduate

  15. A new capacitive/resistive probe method for studying magnetic surfaces

    International Nuclear Information System (INIS)

    Kitajima, Sumio; Takayama, Masakazu; Zama, Tatsuya; Takaya, Kazuhiro; Takeuchi, Nobunao; Watanabe, Hiroshige

    1991-01-01

    A new capacitive/resistive probe method for mapping the magnetic surfaces from resistance or capacitance between a magnetic surface and a vacuum vessel was developed and tested. Those resistances and capacitances can be regarded as components of a simple electrical bridge circuit. This method exploits electrical transient response of the bridge circuit for a square pulse. From equiresistance or equicapacitance points, the magnetic surface structure can be deduced. Measurements on the Tohoku University Heliac, which is a small-size standard heliac, show good agreement with numerical calculations. This method is particularly useful for pulse-operated machines. (author)

  16. Group method analysis of mixed convection stagnation-point flow of non-Newtonian nanofluid over a vertical stretching surface

    Science.gov (United States)

    Nabwey, Hossam A.; Boumazgour, Mohamed; Rashad, A. M.

    2017-07-01

    The group method analysis is applied to study the steady mixed convection stagnation-point flow of a non-Newtonian nanofluid towards a vertical stretching surface. The model utilized for the nanofluid incorporates the Brownian motion and thermophoresis effects. Applying the one-parameter transformation group which reduces the number of independent variables by one and thus, the system of governing partial differential equations has been converted to a set of nonlinear ordinary differential equations, and these equations are then computed numerically using the implicit finite-difference scheme. Comparison with previously published studies is executed and the results are found to be in excellent agreement. Results for the velocity, temperature, and the nanoparticle volume fraction profiles as well as the local skin-friction coefficient and local Nusselt number are presented in graphical and tabular forms, and discussed for different values of the governing parameters to show interesting features of the solutions.

  17. Temperature Dependence of Arn + Cluster Backscattering from Polymer Surfaces: a New Method to Determine the Surface Glass Transition Temperature

    Science.gov (United States)

    Poleunis, Claude; Cristaudo, Vanina; Delcorte, Arnaud

    2018-01-01

    In this work, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to study the intensity variations of the backscattered Arn + clusters as a function of temperature for several amorphous polymer surfaces (polyolefins, polystyrene, and polymethyl methacrylate). For all these investigated polymers, our results show a transition of the ratio Ar2 +/(Ar2 + + Ar3 +) when the temperature is scanned from -120 °C to +125 °C (the exact limits depend on the studied polymer). This transition generally spans over a few tens of degrees and the temperature of the inflection point of each curve is always lower than the bulk glass transition temperature (Tg) reported for the considered polymer. Due to the surface sensitivity of the cluster backscattering process (several nanometers), the presented analysis could provide a new method to specifically evaluate a surface transition temperature of polymers, with the same lateral resolution as the gas cluster beam. [Figure not available: see fulltext.

  18. Temperature Dependence of Arn+ Cluster Backscattering from Polymer Surfaces: a New Method to Determine the Surface Glass Transition Temperature.

    Science.gov (United States)

    Poleunis, Claude; Cristaudo, Vanina; Delcorte, Arnaud

    2018-01-01

    In this work, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to study the intensity variations of the backscattered Ar n + clusters as a function of temperature for several amorphous polymer surfaces (polyolefins, polystyrene, and polymethyl methacrylate). For all these investigated polymers, our results show a transition of the ratio Ar 2 + /(Ar 2 + + Ar 3 + ) when the temperature is scanned from -120 °C to +125 °C (the exact limits depend on the studied polymer). This transition generally spans over a few tens of degrees and the temperature of the inflection point of each curve is always lower than the bulk glass transition temperature (T g ) reported for the considered polymer. Due to the surface sensitivity of the cluster backscattering process (several nanometers), the presented analysis could provide a new method to specifically evaluate a surface transition temperature of polymers, with the same lateral resolution as the gas cluster beam. Graphical abstract ᅟ.

  19. Biomimetic superhydrophobic polyolefin surfaces fabricated with a facile scraping, bonding and peeling method

    Directory of Open Access Journals (Sweden)

    Feng Huanhuan

    2016-01-01

    Full Text Available Inspired by the superhydrophobicity of juicy peach surface, on which microscale hairs are standing vertically to the surface plane, an extremely simple, inexpensive physical method is developed for fabrication of superhydrophobic polyolefin surfaces over large areas. This method includes three steps: abrasive paper scraping, adhesive tape bonding and 90° peeling. Scraping increases the roughness and enhence water contact angles (CAs on polyolefin surfaces. It increases more when the scraped surface are bonded with adhesive types and then then 90° peeled. The CA variation depends on the types of polyolefin and abrasive paper. Superhydrophobic lowdensity polyethylene (LDPE, high-density polyethylene (HDPE and polypropylene (PP surfaces (CA>150° are obtained and they all exhibit very low adhesive force and high resistance to strong acids and bases.

  20. A Two-stage Improvement Method for Robot Based 3D Surface Scanning

    Science.gov (United States)

    He, F. B.; Liang, Y. D.; Wang, R. F.; Lin, Y. S.

    2018-03-01

    As known that the surface of unknown object was difficult to measure or recognize precisely, hence the 3D laser scanning technology was introduced and used properly in surface reconstruction. Usually, the surface scanning speed was slower and the scanning quality would be better, while the speed was faster and the quality would be worse. In this case, the paper presented a new two-stage scanning method in order to pursuit the quality of surface scanning in a faster speed. The first stage was rough scanning to get general point cloud data of object’s surface, and then the second stage was specific scanning to repair missing regions which were determined by chord length discrete method. Meanwhile, a system containing a robotic manipulator and a handy scanner was also developed to implement the two-stage scanning method, and relevant paths were planned according to minimum enclosing ball and regional coverage theories.

  1. A New Approach to Bézier Surface Visualization by a Ray Tracing Method

    OpenAIRE

    Glazs, A; Sisojevs, A

    2008-01-01

    Problem of free – form surfaces visualization is actual in various areas of a science and engineering. One of mathematical models used for this purpose is the mathematical description of a Bézier surface. Classical methods of computer graphics based on polygonal models use only polygonal interpolation of a Bézier surface. Such approach inevitably leads to occurrence of an error and as a consequence – to discrepancy of an image.

  2. Comparison of two split-window methods for retrieving land surface ...

    Indian Academy of Sciences (India)

    Land surface temperature (LST) is a key parameter in environment and earth science study, especially for monitoring drought. The objective of this work is a comparison of two split-window methods: Mao method and Sobrino method, for retrieving LST using MODIS (Moderate-resolution Imaging Spectroradiometer) data in ...

  3. A method for calculating the time-dependent surface temperature of a cylinder containing radioactive waste

    International Nuclear Information System (INIS)

    Fynbo, P.B.

    1981-02-01

    A method is described by which the surface temperature of a steel cylinder containing radioactive waste can be calculated. The method assumes a time-dependent continuous line source in cylindrical symmetry and it applies Laplace transformation. The resultant laplace transform is approximated and then inverted (by convolution). The method is computationally fast and future generalisations to similar problems are suggested. (author)

  4. Ion-step method for surface potential sensing of silicon nanowires

    NARCIS (Netherlands)

    Chen, S.; van Nieuwkasteele, Jan William; van den Berg, Albert; Eijkel, Jan C.T.

    2016-01-01

    This paper presents a novel stimulus-response method for surface potential sensing of silicon nanowire (Si NW) field-effect transistors. When an "ion-step" from low to high ionic strength is given as a stimulus to the gate oxide surface, an increase of double layer capacitance is therefore expected.

  5. A new practical method to reconstruct cerebral surface anatomical images for computer-assisted neurosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Shin; Kato, Amami; Yoshimine, Toshiki; Taneda, Mamoru; Hayakawa, Toru (Osaka Univ. (Japan). Faculty of Medicine)

    1994-03-01

    Authors have developed a new, practical method to reconstruct cerebral surface anatomical images for better surgical orientation and surgical planning. Using a personal computer and a commercially available image handling software, an area encompassing the surface gyri and sulci is selected from the most superficial slice of T1-weighted MR images, after which this selected area, on adjusting the alignment, is overlayed onto the next superficial slice. By repeating this procedure for 4 to 7 times, the brain surface image obtained clearly displays the gyri and sulci. A vascular image of the cerebral surface can also be obtained by this same method by using T2-weighted images or MR angiograms. Then, by combining both the brain surface and vascular images, an anatomically reconstructed image of the cerebral surface is achieved. The outlines of the lesion or ventricles can also be added, if necessary, and the entire procedure takes an hour or less. The authors believe that this method is superior to conventional surface anatomy scanning for discriminating anatomical structures close to a lesion. This surface anatomical imaging method has been used for the surgical planning and its use helped to minimize surgical damage to the eloquent areas. (author).

  6. Whole-surface round object imaging method using line-scan hyperspectral imaging system

    Science.gov (United States)

    To achieve comprehensive online quality and safety inspection of fruits, whole-surface sample presentation and imaging regimes must be considered. Specifically, a round object sample presentation method is under development to achieve effective whole-surface sample evaluation based on the use of a s...

  7. On the Surface Free Energy of PVC/EVA Polymer Blends: Comparison of Different Calculation Methods.

    Science.gov (United States)

    Michalski; Hardy; Saramago

    1998-12-01

    The surface free energy of polymeric films of polyvinylchloride (PVC) + poly(ethylene-co-vinylacetate) (EVA) blends was calculated using the van Oss treatment (Lifshitz and electron donor-electron acceptor components of surface free energy) and the Owens-Wendt treatment (dispersive and nondispersive components of surface free energy). Surface free energy results were found to be greatly dependent on the calculation method and on the number of standard liquids used for contact angle measurements. The nondispersive/donor-acceptor surface free energy component and the total surface free energy of polymeric films were always higher when the van Oss treatment was used compared to the Owens-Wendt treatment. Conversely, both methods led to similar apolar/Lifshitz components. All the calculation methods were in good agreement for the surface free energy of PVC; however, a discrepancy between the methods arose as EVA content in the blends increased. It seems that there is not yet a definite solution for the calculation of solid surface free energy. Further developments of existing models are needed in order to gain consistency when calculating this important physicochemical quantity. Copyright 1998 Academic Press.

  8. Method for the indication of failures on the surface of magnetizable workpieces

    International Nuclear Information System (INIS)

    1976-01-01

    Using the magnetic powder method as a quality test of ferromagnetic work pieces, solid iron powder, pigment and lac are put on the surface and the powder agglomeration sprayed with a solvent. This way the varnish softens and adheres the powder to the surface. A non-explosive solvent is used and with help of additives the contrast increases. (TK) [de

  9. Methods for surface treating metals, ceramics, and plastics before adhesive bonding

    International Nuclear Information System (INIS)

    Althouse, L.P.

    1976-01-01

    Methods for pretreating the surfaces of metals, ceramics, and plastics before they are coated with adhesive and used in assembly are described. The treatments recommended have been used successfully in the laboratory at LLL. Many are used in the assembly of nuclear devices. However, an unusual alloy or complex configuration may require trials before a specific surface treatment is chosen

  10. Surface plasmon resonance is an analytically sensitive method for antigen profiling of extracellular vesicles

    NARCIS (Netherlands)

    Gool, Elmar L.; Stojanovic, Ivan; Schasfoort, Richardus B.M.; Sturk, Auguste; Van Leeuwen, Ton G.; Nieuwland, Rienk; Terstappen, Leon W.M.M.; Coumans, Frank A.W.

    2017-01-01

    BACKGROUND: Identification, enumeration, and characterization of extracellular vesicles (EVs) are hampered by the small size of EVs, a low refractive index, and low numbers of antigens on their surface. METHODS: We investigated the potential of a 48- multiplex surface plasmon resonance imaging

  11. Surface exposure dating of non-terrestrial bodies using optically stimulated luminescence: A new method

    DEFF Research Database (Denmark)

    Sohbati, Reza; Jain, Mayank; Murray, Andrew

    2012-01-01

    We propose a new method for in situ surface exposure dating of non-terrestrial geomorphological features using optically stimulated luminescence (OSL); our approach is based on the progressive emptying of trapped charge with exposure to light at depth into a mineral surface. A complete model...

  12. Adhesion of resin composites to biomaterials in dentistry : an evaluation of surface conditioning methods

    NARCIS (Netherlands)

    Özcan, Mutlu

    2003-01-01

    Since previous investigations revealed that most clinical failures in adhesively luted ceramic restorations initiate from the cementation or internal surfaces, the study presented in Chapter II evaluated the effect of three different surface conditioning methods on the bond strength of a Bis-GMA

  13. Electronic interconnects and devices with topological surface states and methods for fabricating same

    Energy Technology Data Exchange (ETDEWEB)

    Yazdani, Ali; Ong, N. Phuan; Cava, Robert J.

    2016-05-03

    An interconnect is disclosed with enhanced immunity of electrical conductivity to defects. The interconnect includes a material with charge carriers having topological surface states. Also disclosed is a method for fabricating such interconnects. Also disclosed is an integrated circuit including such interconnects. Also disclosed is a gated electronic device including a material with charge carriers having topological surface states.

  14. Electronic interconnects and devices with topological surface states and methods for fabricating same

    Energy Technology Data Exchange (ETDEWEB)

    Yazdani, Ali; Ong, N. Phuan; Cava, Robert J.

    2017-04-04

    An interconnect is disclosed with enhanced immunity of electrical conductivity to defects. The interconnect includes a material with charge carriers having topological surface states. Also disclosed is a method for fabricating such interconnects. Also disclosed is an integrated circuit including such interconnects. Also disclosed is a gated electronic device including a material with charge carriers having topological surface states.

  15. Planar integrated optical methods for examining thin films and their surface adlayers.

    Science.gov (United States)

    Plowman, T E; Saavedra, S S; Reichert, W M

    1998-03-01

    Thin film integrated optical waveguides (IOWs) have gained acceptance as a method for characterizing ultrathin dielectrical films and adlayers bound to the film surface. Here, we present the expressions that govern IOW methods as well as describe the common experimental configurations used in attenuated total reflection, fluorescence and Raman applications. The applications of these techniques to the study of adsorbed or surface-bound proteins to polymer and glass waveguides are reviewed.

  16. Condition Assessment for Wastewater Pipes: Method for Assessing Cracking and Surface Damage of Concrete Pipes

    OpenAIRE

    Hauge, Petter

    2013-01-01

    The objective of the Master Thesis has been to provide an improved method for condition assessment, which will give a better correlation between Condition class and actual Condition of concrete pipes with cracking and/or surface damages. Additionally improvement of the characterization of cracking (SR) and surface (KO) damages was a sub goal.Based on the findings described in my Thesis and my Specialization Project (Hauge 2012), I recommend that the Norwegian condition assessment method based...

  17. The measurement of surface roughness to determine the suitability of different methods for stone cleaning

    International Nuclear Information System (INIS)

    Vazquez-Calvo, Carmen; Alvarez de Buergo, Monica; Fort, Rafael; Varas-Muriel, Maria Jose

    2012-01-01

    The roughness of stone surface was measured, before and after bead blasting-based cleaning methods, to select the most efficient one to be used in masonry and stonework of specific areas of the Cathedral of Segovia (Spain). These types of cleaning methods can, besides the removal of soiling and surface deposits, leave a rougher surface, which would mean higher and more rapid water retention and deposit accumulation due to a specific surface increase, therefore accelerating stone decay. Or, in contrast, the cleaning method can be so aggressive that it can smooth the surface by reducing its roughness, a fact that usually corresponds to excessive material removal—soot and deposits–-but also part of the stone substrate. Roughness results were complemented with scanning electron microscopy observations and analyses and colour measurements. Finally, it was possible to select the best cleaning method among the six that were analysed, for different areas and different stone materials. Therefore, this study confirms the measurement of surface roughness as a reliable test to determine the suitability of stone cleaning methods; it is a non-destructive technique, portable and friendly to use, which can help us to rapidly assess—together with other techniques—the efficacy and aggressiveness of the stone cleaning method. (paper)

  18. A hybrid 3D SEM reconstruction method optimized for complex geologic material surfaces.

    Science.gov (United States)

    Yan, Shang; Adegbule, Aderonke; Kibbey, Tohren C G

    2017-08-01

    Reconstruction methods are widely used to extract three-dimensional information from scanning electron microscope (SEM) images. This paper presents a new hybrid reconstruction method that combines stereoscopic reconstruction with shape-from-shading calculations to generate highly-detailed elevation maps from SEM image pairs. The method makes use of an imaged glass sphere to determine the quantitative relationship between observed intensity and angles between the beam and surface normal, and the detector and surface normal. Two specific equations are derived to make use of image intensity information in creating the final elevation map. The equations are used together, one making use of intensities in the two images, the other making use of intensities within a single image. The method is specifically designed for SEM images captured with a single secondary electron detector, and is optimized to capture maximum detail from complex natural surfaces. The method is illustrated with a complex structured abrasive material, and a rough natural sand grain. Results show that the method is capable of capturing details such as angular surface features, varying surface roughness, and surface striations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The Soft-Confined Method for Creating Molecular Models of Amorphous Polymer Surfaces

    KAUST Repository

    Liu, Hongyi

    2012-02-09

    The goal of this work was to use molecular dynamics (MD) simulations to build amorphous surface layers of polypropylene (PP) and cellulose and to inspect their physical and interfacial properties. A new method to produce molecular models for these surfaces was developed, which involved the use of a "soft" confining layer comprised of a xenon crystal. This method compacts the polymers into a density distribution and a degree of molecular surface roughness that corresponds well to experimental values. In addition, calculated properties such as density, cohesive energy density, coefficient of thermal expansion, and the surface energy agree with experimental values and thus validate the use of soft confining layers. The method can be applied to polymers with a linear backbone such as PP as well as those whose backbones contain rings, such as cellulose. The developed PP and cellulose surfaces were characterized by their interactions with water. It was found that a water nanodroplet spreads on the amorphous cellulose surfaces, but there was no significant change in the dimension of the droplet on the PP surface; the resulting MD water contact angles on PP and amorphous cellulose surfaces were determined to be 106 and 33°, respectively. © 2012 American Chemical Society.

  20. Ab initio analysis of a vacancy and a self-interstitial near single crystal silicon surfaces: Implications for intrinsic point defect incorporation during crystal growth from a melt

    Energy Technology Data Exchange (ETDEWEB)

    Kamiyama, Eiji; Sueoka, Koji [Department of Communication Engineering, Okayama Prefectural University, 111 Kuboki, Soja, Okayama 719-1197 (Japan); Vanhellemont, Jan [Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, Gent 9000 (Belgium)

    2012-10-15

    The microscopic model of the Si (001) crystal surface was investigated by first principles calculations to clarify the behavior of intrinsic point defects near crystal surfaces. A c(4 x 2) structure model was used to describe the crystal surface in contact with vacuum. The calculations show lower formation energy near the surface and the existence of formation energy differences between the surface and the bulk for both types of intrinsic point defects. The tetrahedral (T)-site and the dumbbell (DB)-site, in which a Si atom is captured from the surface and forms a self-interstitial, are found as stable sites near the third atomic layer. The T-site has a barrier of 0.48 eV, whereas the DB-site has no barrier for the interstitial to penetrate into the crystal from the vacuum. Si atoms in a melt can migrate and reach at the third layer during crystal growth when bulk diffusion coefficient is used. Therefore, the melt/solid interface is always a source of intrinsic point defects. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Surface exposure dating of non-terrestrial bodies using optically stimulated luminescence: A new method

    DEFF Research Database (Denmark)

    Sohbati, Reza; Jain, Mayank; Murray, Andrew

    2012-01-01

    We propose a new method for in situ surface exposure dating of non-terrestrial geomorphological features using optically stimulated luminescence (OSL); our approach is based on the progressive emptying of trapped charge with exposure to light at depth into a mineral surface. A complete model...... will be applicable over the last 100 ka. The method is ideally suited to in situ measurement using existing technology developed for space applications, and so offers for the first time the realistic possibility of direct determination of exposure ages of young non-terrestrial surfaces. © 2012 Elsevier Inc. All...... rights reserved....

  2. Systems and Methods of Laser Texturing of Material Surfaces and Their Applications

    Science.gov (United States)

    Gupta, Mool C. (Inventor); Nayak, Barada K. (Inventor)

    2014-01-01

    The surface of a material is textured and by exposing the surface to pulses from an ultrafast laser. The laser treatment causes pillars to form on the treated surface. These pillars provide for greater light absorption. Texturing and crystallization can be carried out as a single step process. The crystallization of the material provides for higher electric conductivity and changes in optical and electronic properties of the material. The method may be performed in vacuum or a gaseous environment. The gaseous environment may aid in texturing and/or modifying physical and chemical properties of the surfaces. This method may be used on various material surfaces, such as semiconductors, metals and their alloys, ceramics, polymers, glasses, composites, as well as crystalline, nanocrystalline, polycrystalline, microcrystalline, and amorphous phases.

  3. Fabricating superhydrophobic polymer surfaces with excellent abrasion resistance by a simple lamination templating method.

    Science.gov (United States)

    Xu, Qian Feng; Mondal, Bikash; Lyons, Alan M

    2011-09-01

    Fabricating robust superhydrophobic surfaces for commercial applications is challenging as the fine-scale surface features, necessary to achieve superhydrophobicity, are susceptible to mechanical damage. Herein, we report a simple and inexpensive lamination templating method to create superhydrophobic polymer surfaces with excellent abrasion resistance and water pressure stability. To fabricate the surfaces, polyethylene films were laminated against woven wire mesh templates. After cooling, the mesh was peeled from the polymer creating a 3D array of ordered polymer microposts on the polymer surface. The resulting texture is monolithic with the polymer film and requires no chemical modification to exhibit superhydrophobicity. By controlling lamination parameters and mesh dimensions, polyethylene surfaces were fabricated that exhibit static contact angles of 160° and slip angles of 5°. Chemical and mechanical stability was evaluated using an array of manual tests as well as a standard reciprocating abraser test. Surfaces remained superhydrophobic after more than 5500 abrasion cycles at a pressure of 32.0 kPa. In addition, the surface remains dry after immersing into water for 5 h at 55 kPa. This method is environmental friendly, as it employs no solvents or harsh chemicals and may provide an economically viable path to manufacture large areas of mechanically robust superhydrophobic surfaces from inexpensive polymers and reusable templates.

  4. Improved atmospheric effects elimination method for pBRDF models of painted surfaces.

    Science.gov (United States)

    Zhang, Ying; Zhang, Yi; Zhao, Huijie; Wang, Zeying

    2017-07-10

    A method for eliminating atmospheric effects in polarimetric imaging remote sensing detection was developed by combining the shadowing method and radiative transfer (RT) model. First, a polarized bidirectional reflectance distribution function (pBRDF) model of painted surfaces was constructed. Using the resulting polarimetric radiance composition, the atmospheric effects elimination method was developed and compared to Shell's method. Experiments were performed using a liquid-crystal-variable-retarder-based imaging polarimeter to obtain the surface pBRDFs. The proposed method showed better performance under different weather conditions than Shell's method. Furthermore, the error was below 4.8% in the proposed method (6.8% in Shell's method), indicating improved quantitative accuracy of the target physical parameters in remote sensing.

  5. Different methods to alter surface morphology of high aspect ratio structures

    Energy Technology Data Exchange (ETDEWEB)

    Leber, M., E-mail: moritz.leber@utah.edu [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT (United States); Shandhi, M.M.H. [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT (United States); Hogan, A. [Blackrock Microsystems, Salt Lake City, UT (United States); Solzbacher, F. [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT (United States); Bhandari, R.; Negi, S. [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT (United States); Blackrock Microsystems, Salt Lake City, UT (United States)

    2016-03-01

    Graphical abstract: Surface engineering of high aspect ratio silicon structures. - Highlights: • Multiple roughening techniques for high aspect ratio devices were investigated. • Modification of surface morphology of high aspect ratio silicon devices (1:15). • Decrease of 76% in impedance proves significant increase in surface area. - Abstract: In various applications such as neural prostheses or solar cells, there is a need to alter the surface morphology of high aspect ratio structures so that the real surface area is greater than geometrical area. The change in surface morphology enhances the devices functionality. One of the applications of altering the surface morphology is of neural implants such as the Utah electrode array (UEA) that communicate with single neurons by charge injection induced stimulation or by recording electrical neural signals. For high selectivity between single cells of the nervous system, the electrode surface area is required to be as small as possible, while the impedance is required to be as low as possible for good signal to noise ratios (SNR) during neural recording. For stimulation, high charge injection and charge transfer capacities of the electrodes are required, which increase with the electrode surface. Traditionally, researchers have worked with either increasing the roughness of the existing metallization (platinum grey, black) or other materials such as Iridium Oxide and PEDOT. All of these previously investigated methods lead to more complicated metal deposition processes that are difficult to control and often have a critical impact on the mechanical properties of the metal films. Therefore, a modification of the surface underneath the electrode's coating will increase its surface area while maintaining the standard and well controlled metal deposition process. In this work, the surfaces of the silicon micro-needles were engineered by creating a defined microstructure on the electrodes surface using several

  6. Effect of Alumina Incorporation on the Surface Mineralization and Degradation of a Bioactive Glass (CaO-MgO-SiO₂-Na₂O-P₂O₅-CaF₂)-Glycerol Paste.

    Science.gov (United States)

    Tulyaganov, Dilshat; Abdukayumov, Khasan; Ruzimuradov, Olim; Hojamberdiev, Mirabbos; Ionescu, Emanuel; Riedel, Ralf

    2017-11-18

    This study investigates the dissolution behavior as well as the surface biomineralization in simulated body fluid (SBF) of a paste composed of glycerol (gly) and a bioactive glass in the system CaO-MgO-SiO₂-Na₂O-P₂O₅-CaF₂ (BG). The synthesis of the bioactive glass in an alumina crucible has been shown to significantly affect its bioactivity due to the incorporation of aluminum (ca. 1.3-1.4 wt %) into the glass network. Thus, the kinetics of the hydroxyapatite (HA) mineralization on the glass prepared in the alumina crucible was found to be slower than that reported for the same glass composition prepared in a Pt crucible. It is considered that the synthesis conditions lead to the incorporation of small amount of aluminum into the BG network and thus delay the HA mineralization. Interestingly, the BG-gly paste was shown to have significantly higher bioactivity than that of the as-prepared BG. Structural analysis of the paste indicate that glycerol chemically interacts with the glass surface and strongly alter the glass network architecture, thus generating a more depolymerized network, as well as an increased amount of silanol groups at the surface of the glass. In particular, BG-gly paste features early intermediate calcite precipitation during immersion in SBF, followed by hydroxyapatite formation after ca. seven days of SBF exposure; whereas the HA mineralization seems to be suppressed in BG, probably a consequence of the incorporation of aluminum into the glass network. The results obtained within the present study reveal the positive effect of using pastes based on bioactive glasses and organic carriers (here alcohols) which may be of interest not only due to their advantageous visco-elastic properties, but also due to the possibility of enhancing the glass bioactivity upon surface interactions with the organic carrier.

  7. Effect of Alumina Incorporation on the Surface Mineralization and Degradation of a Bioactive Glass (CaO-MgO-SiO2-Na2O-P2O5-CaF2-Glycerol Paste

    Directory of Open Access Journals (Sweden)

    Dilshat Tulyaganov

    2017-11-01

    Full Text Available This study investigates the dissolution behavior as well as the surface biomineralization in simulated body fluid (SBF of a paste composed of glycerol (gly and a bioactive glass in the system CaO-MgO-SiO2-Na2O-P2O5-CaF2 (BG. The synthesis of the bioactive glass in an alumina crucible has been shown to significantly affect its bioactivity due to the incorporation of aluminum (ca. 1.3–1.4 wt % into the glass network. Thus, the kinetics of the hydroxyapatite (HA mineralization on the glass prepared in the alumina crucible was found to be slower than that reported for the same glass composition prepared in a Pt crucible. It is considered that the synthesis conditions lead to the incorporation of small amount of aluminum into the BG network and thus delay the HA mineralization. Interestingly, the BG-gly paste was shown to have significantly higher bioactivity than that of the as-prepared BG. Structural analysis of the paste indicate that glycerol chemically interacts with the glass surface and strongly alter the glass network architecture, thus generating a more depolymerized network, as well as an increased amount of silanol groups at the surface of the glass. In particular, BG-gly paste features early intermediate calcite precipitation during immersion in SBF, followed by hydroxyapatite formation after ca. seven days of SBF exposure; whereas the HA mineralization seems to be suppressed in BG, probably a consequence of the incorporation of aluminum into the glass network. The results obtained within the present study reveal the positive effect of using pastes based on bioactive glasses and organic carriers (here alcohols which may be of interest not only due to their advantageous visco-elastic properties, but also due to the possibility of enhancing the glass bioactivity upon surface interactions with the organic carrier.

  8. Laser pulse transient method for measuring the normal spectral emissivity of samples with arbitrary surface quality

    Science.gov (United States)

    Jeromen, A.; Grabec, I.; Govekar, E.

    2008-09-01

    A laser pulse transient method for measuring normal spectral emissivity is described. In this method, a laser pulse ( λ=1064 nm) irradiates the top surface of a flat specimen. A two-dimensional temperature response of the bottom surface is measured with a calibrated thermographic camera. By solving an axisymmetric boundary value heat conduction problem, the normal spectral emissivity at 1064 nm is determined by using an iterative nonlinear least-squares estimation procedure. The method can be applied to arbitrary sample surface quality. The method is tested on a nickel specimen and used to determine the normal spectral emissivity of AISI 304 stainless steel. The expanded combined uncertainty of the method has been estimated to be 18%.

  9. Facile method to fabricate raspberry-like particulate films for superhydrophobic surfaces.

    Science.gov (United States)

    Tsai, Hui-Jung; Lee, Yuh-Lang

    2007-12-04

    A facile method using layer-by-layer assembly of silica particles is proposed to prepare raspberry-like particulate films for the fabrication of superhydrophobic surfaces. Silica particles 0.5 microm in diameter were used to prepare a surface with a microscale roughness. Nanosized silica particles were then assembled on the particulate film to construct a finer structure on top of the coarse one. After surface modification with dodecyltrichlorosilane, the advancing and receding contact angles of water on the dual-sized structured surface were 169 and 165 degrees , respectively. The scale ratio of the micro/nano surface structure and the regularity of the particulate films on the superhydrophobic surface performance are discussed.

  10. Development and application of QM/MM methods to study the solvation effects and surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Dibya, Pooja Arora [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Quantum mechanical (QM) calculations have the advantage of attaining high-level accuracy, however QM calculations become computationally inefficient as the size of the system grows. Solving complex molecular problems on large systems and ensembles by using quantum mechanics still poses a challenge in terms of the computational cost. Methods that are based on classical mechanics are an inexpensive alternative, but they lack accuracy. A good trade off between accuracy and efficiency is achieved by combining QM methods with molecular mechanics (MM) methods to use the robustness of the QM methods in terms of accuracy and the MM methods to minimize the computational cost. Two types of QM combined with MM (QM/MM) methods are the main focus of the present dissertation: the application and development of QM/MM methods for solvation studies and reactions on the Si(100) surface. The solvation studies were performed using a discreet solvation model that is largely based on first principles called the effective fragment potential method (EFP). The main idea of combining the EFP method with quantum mechanics is to accurately treat the solute-solvent and solvent-solvent interactions, such as electrostatic, polarization, dispersion and charge transfer, that are important in correctly calculating solvent effects on systems of interest. A second QM/MM method called SIMOMM (surface integrated molecular orbital molecular mechanics) is a hybrid QM/MM embedded cluster model that mimics the real surface.3 This method was employed to calculate the potential energy surfaces for reactions of atomic O on the Si(100) surface. The hybrid QM/MM method is a computationally inexpensive approach for studying reactions on larger surfaces in a reasonably accurate and efficient manner. This thesis is comprised of four chapters: Chapter 1 describes the general overview and motivation of the dissertation and gives a broad background of the computational methods that have been employed in this work

  11. Reliability-based design optimization via high order response surface method

    International Nuclear Information System (INIS)

    Li, Hong Shuang

    2013-01-01

    To reduce the computational effort of reliability-based design optimization (RBDO), the response surface method (RSM) has been widely used to evaluate reliability constraints. We propose an efficient methodology for solving RBDO problems based on an improved high order response surface method (HORSM) that takes advantage of an efficient sampling method, Hermite polynomials and uncertainty contribution concept to construct a high order response surface function with cross terms for reliability analysis. The sampling method generates supporting points from Gauss-Hermite quadrature points, which can be used to approximate response surface function without cross terms, to identify the highest order of each random variable and to determine the significant variables connected with point estimate method. The cross terms between two significant random variables are added to the response surface function to improve the approximation accuracy. Integrating the nested strategy, the improved HORSM is explored in solving RBDO problems. Additionally, a sampling based reliability sensitivity analysis method is employed to reduce the computational effort further when design variables are distributional parameters of input random variables. The proposed methodology is applied on two test problems to validate its accuracy and efficiency. The proposed methodology is more efficient than first order reliability method based RBDO and Monte Carlo simulation based RBDO, and enables the use of RBDO as a practical design tool.

  12. A high-reflective surface measurement method based on conoscopic holography technology

    Science.gov (United States)

    Cheng, Xu; Li, ZhongWei; Shi, YuSheng; Zhao, HengShuang; Zhan, Guomin

    2014-11-01

    Measuring high-reflective surfaces using optical method is always a big challenging problem. This paper presents a high-reflective surface measurement method based on conoscopic holography technology using a 4D motion platform equipped with a conoscopic holography optical probe. There are two key problems needed to solve before the automate scan of the complex shape surface: the coordinate calibration and the path planning. To improve the calibration efficiency and accuracy, the coordinate calibration is divided into two parts: the rough calibration and the accurate registration. The path planning consists of two aspects including: the path points generation and the path points verification. In addition, by scanning the objects having high-reflective surfaces, such as the metal blades, coins and other work-pieces, the efficiency of the measurement method has been verified.

  13. Development of autoradiographic method for measuring sorption of radionuclides on natural fracture surfaces

    International Nuclear Information System (INIS)

    Muuronen, S.

    1983-11-01

    On the basis of positive results about sorption of radionuclides in rock thin sections an autoradiographic method applicable for measurement sorption of radionuclides on rough rock surfaces was developed. There is no method available because 1) a plane film cannot be used because due to the roughness of rock surfaces 2) rock samples used in this investigation cannot be studied with microscopes and 3) autoradiogram cannot be studied fixed on the surface of a rock sample because the colours of the minerals in the sample will interfere with the interpretation. This report discusses experimental work done to find an useful proedure. In the development of the method main emphasis was put on investigation of the following steps: 1) preparation of the sample for equilibration and spiking; 2) properties of the covering paint for the rock surface and 3) testing of autoradiographic methods using different nuclear emulsions. As the result of these experiments promising autoradiograms with gel emulsion for sawed rock surfaces and with stripping film for rough rock surfaces were obtained. The mineralogic disribution of sorbed activity is easily seen in autoradiograms. Much work must still be done to get reliable quantitative information from autoradiograms. For developing of the autoradiographic method sawed plane rock samples of quartz feldspar intergrowth, pegmatite and limestone were used. In addition core samples of tonalite and mica gneiss from Olkiluoto were utilized. The distribution coefficients (Ksub(a)) obtained for cesium were 560 x 10 -4 and 620 x 10 -4 m 3 /m 2 for tonalite and mica gneiss, respectively. The results are little higher but of the same order of magnitude as obtained by the autoradiographic method using rock thin sections and by the batch method using crused samples. The natural fracture surface sorption study is a logical step in determining the scaling factor from laboratory to field studies. Field data will be needed to determine whether laboratory

  14. Pre-absorbed immunoproteomics: a novel method for the detection of Streptococcus suis surface proteins.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available Streptococcus suis serotype 2 (SS2 is a zoonotic pathogen that can cause infections in pigs and humans. Bacterial surface proteins are often investigated as potential vaccine candidates and biomarkers of virulence. In this study, a novel method for identifying bacterial surface proteins is presented, which combines immunoproteomic and immunoserologic techniques. Critical to the success of this new method is an improved procedure for generating two-dimensional electrophoresis gel profiles of S. suis proteins. The S. suis surface proteins identified in this study include muramidase-released protein precursor (MRP and an ABC transporter protein, while MRP is thought to be one of the main virulence factors in SS2 located on the bacterial surface. Herein, we demonstrate that the ABC transporter protein can bind to HEp-2 cells, which strongly suggests that this protein is located on the bacterial cell surface and may be involved in pathogenesis. An immunofluorescence assay confirmed that the ABC transporter is localized to the bacterial outer surface. This new method may prove to be a useful tool for identifying surface proteins, and aid in the development of new vaccine subunits and disease diagnostics.

  15. Self-cleaning Foliar Surfaces Characterization using RIMAPS Technique and Variogram Method

    International Nuclear Information System (INIS)

    Rosi, Pablo E.

    2002-01-01

    Along the last ten years many important studies about characterization of self-cleaning foliar surfaces have been done and focused new interest on this kind of surfaces.These studies were possible due to the development of a novel preparation technique for this biological material that let us observe the delicate structures of a foliar surface under scanning electron microscope (S.E.M.).This technique consists of replacing the natural water of the specimen by glycerol. Digital S.E.M. images from both self-cleaning and non-self-cleaning foliar surfaces were obtained and analyzed using RIMAPS technique and Variograms method. Our results revealed the existence of a common and exclusive geometrical pattern that is found in species which present self-cleaning foliar surfaces.This pattern combines at least nine different directions.The results from the Variograms method showed that the stomata play a key role in the determination of foliar surface roughness. In addition, spectra from RIMAPS technique constitute a fingerprint of a foliar surface so they can be used to find evolutionary relationships among species.Further studies will provide more detailed information to fully elucidate the self-cleaning pattern, so it might be possible to reproduce it on an artificial surface and make it self-cleaning

  16. A new method for solid surface topographical studies using nematic liquid crystals

    Science.gov (United States)

    Baber, N.; Strugalski, Z.

    1984-03-01

    A new simple method has been developed to investigate the topography of a wide range of solid surfaces using nematic liquid crystals. Polarizing microscopy is employed. The usefulness of the method for detecting weak mechanical effects has been demonstrated. An application in criminology is foreseen.

  17. Variant of a volume-of-fluid method for surface tension-dominant two ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... The capabilities of the volume-of-fluid method for the calculation of surface tension-dominant two-phase flows are explained. The accurate calculation of the interface remains a problem for the volume-of-fluid method if the density ratios of the fluids in different phases are high. The simulations of bubble ...

  18. Seismo-acoustic location method for small-magnitude surface explosions

    Science.gov (United States)

    Che, I.-Y.; Shin, J. S.; Kang, I. B.

    2009-02-01

    The aims of this study were to develop an improved method using infrasound observations at multiple seismo-acoustic arrays for locating small-magnitude surface explosions at regional distances and to apply the method to ground-truth blasting events for validation. The location method is based on a nonlinear grid search using the travel times and back azimuths of infrasonic signals generated from the surface explosions and on seismic parameters that are independently determined by routine seismic monitoring systems. Specifically, the method utilizes wind-corrected infrasonic azimuths in grid searching to constrain the grids according to nearness to feasibly real observations. Ground-truth events were recorded by a seismo-acoustic station temporarily operated inside an open-pit mine and then used to investigate the improvement by the location method. The method improved the locating of ground-truth events by approximately 50% compared to the seismic location results. Surface explosions generating both seismic and infrasonic signals could be located independently by the seismic location, infrasonic-azimuth intersection, and seismo-acoustic location method, respectively. This method can be applied to automatic seismic/infrasonic monitoring systems as an additional location tool for explosion-induced seismic events, allowing for simultaneous monitoring for surface explosions and reduced risk of false location results.

  19. Effect of surface conditioning methods on the bond strength of luting cement to ceramics

    NARCIS (Netherlands)

    Ozcan, M; Vallittu, PK; Özcan, Mutlu; Vallittu, Pekka K.

    2003-01-01

    Objectives. This study evaluated the effect of three different surface conditioning methods on the bond strength of a Bis-GMA based luting cement to six commercial dental ceramics. Methods. Six disc shaped ceramic specimens (glass ceramics, glass infiltrated alumina, glass infiltrated zirconium

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

    NARCIS (Netherlands)

    Gagarina, Elena; Ambati, V.R.; van der Vegt, Jacobus J.W.; Bokhove, Onno

    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

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

    NARCIS (Netherlands)

    Gagarina, Elena; van der Vegt, Jacobus J.W.; Ambati, V.R.; Bokhove, Onno

    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

  2. Study of the possibilities of using nuclear methods for characterizing the surface region of glasses

    International Nuclear Information System (INIS)

    Hsiung, P.

    1983-01-01

    Following a review of the different methods used for the analysis of surfaces, we give a detailed description of charged particle elastic backscattering and the experimental devices. We then apply this method to the study of the lixiviation of borosilicate glasses in aqueous media and to the characterization of two heavy elements, cerium and thorium and their possible interaction in simple borosilicates [fr

  3. [Modern methods for studying the surface of titanium implants (literature review)].

    Science.gov (United States)

    Suba, Csongor; Velich, Norbert; Vörös, János; Turi, Csaba; Szabó, György

    2004-02-01

    Studies of the coatings found on the surface of titanium implants employed in oral surgery are indispensable for understanding the interactions between the organism and the implant. This paper surveys the theory and practical applicability of the methods most frequently applied to study the surface structure and composition of the material. Detailed accounts are given of various structure investigation methods: scanning electron microscopy, stereo scanning electron microscopy, X-ray diffraction, atomic force microscopy and interference microscopy; and of various composition investigation methods: secondary ion mass spectroscopy, X-ray photoelectron spectroscopy, Auger electron spectroscopy; and also of the corrosion procedures for the study of electrochemical behaviour.

  4. Green's function surface-integral method for nonlocal response of plasmonic nanowires in arbitrary dielectric environments

    DEFF Research Database (Denmark)

    Yan, Wei; Mortensen, N. Asger; Wubs, Martijn

    2013-01-01

    We develop a nonlocal-response generalization to the Green's function surface-integral method (GSIM), also known as the boundary-element method. This numerically efficient method can accurately describe the linear hydrodynamic nonlocal response of arbitrarily shaped plasmonic nanowires in arbitrary...... and the longitudinal wave number become smaller, or when the effective background permittivity or the mode inhomogeneity increase. The inhomogeneity can be expressed in terms of an effective angular momentum of the surface-plasmon mode. We compare local and nonlocal response of freestanding nanowires, and of nanowires...

  5. An adaptive finite element method for simulating surface tension with the gradient theory of fluid interfaces

    KAUST Repository

    Kou, Jisheng

    2014-01-01

    The gradient theory for the surface tension of simple fluids and mixtures is rigorously analyzed based on mathematical theory. The finite element approximation of surface tension is developed and analyzed, and moreover, an adaptive finite element method based on a physical-based estimator is proposed and it can be coupled efficiently with Newton\\'s method as well. The numerical tests are carried out both to verify the proposed theory and to demonstrate the efficiency of the proposed method. © 2013 Elsevier B.V. All rights reserved.

  6. Facile method to stain the bacterial cell surface for super-resolution fluorescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gunsolus, Ian L.; Hu, Dehong; Mihai, Cosmin; Lohse, Samuel E.; Lee, Chang-Soo; Torelli, Marco; Hamers, Robert J.; Murphy, Catherine; Orr, Galya; Haynes, Christy L.

    2014-01-01

    A method to fluorescently stain the surfaces of both Gram-negative and Gram-positive bacterial cells compatible with super-resolution fluorescence microscopy is presented. This method utilizes a commercially-available fluorescent probe to label primary amines at the surface of the cell. We demonstrate efficient staining of two bacterial strains, the Gram-negative Shewanella oneidensis MR-1 and the Gram-positive Bacillus subtilis 168. Using structured illumination microscopy and stochastic optical reconstruction microscopy, which require high quantum yield or specialized dyes, we show that this staining method may be used to resolve the bacterial cell surface with sub-diffraction-limited resolution. We further use this method to identify localization patterns of nanomaterials, specifically cadmium selenide quantum dots, following interaction with bacterial cells.

  7. Stability analysis of a partitioned iterative method for steady free surface flow

    Science.gov (United States)

    Demeester, Toon; Degroote, Joris; Vierendeels, Jan

    2018-02-01

    This note considers the steady free surface (FS) flow problem as encountered in the paper by van Brummelen et al. [1]. In that paper, steady flow of water in a two-dimensional slice of an infinitely wide open channel with a particular bottom wall is calculated as the first step in the development of a 3D surface fitting method for steady flow around ships. In these water-air flows, the influence of air is usually negligible due to the large difference in density. Contrary to surface capturing methods which are typically multiphase techniques (such as the volume-of-fluid method), fitting methods usually consider only the water phase. The latter approach requires appropriate FS boundary conditions. The dynamic boundary condition (DBC) used here assumes that the pressure is constant (atmospheric) at the FS and the shear stresses are zero. The kinematic boundary condition (KBC) states that the FS is impermeable.

  8. Bone surface enhancement in ultrasound images using a new Doppler-based acquisition/processing method

    Science.gov (United States)

    Yang, Xu; Tang, Songyuan; Tasciotti, Ennio; Righetti, Raffaella

    2018-01-01

    Ultrasound (US) imaging has long been considered as a potential aid in orthopedic surgeries. US technologies are safe, portable and do not use radiations. This would make them a desirable tool for real-time assessment of fractures and to monitor fracture healing. However, image quality of US imaging methods in bone applications is limited by speckle, attenuation, shadow, multiple reflections and other imaging artifacts. While bone surfaces typically appear in US images as somewhat ‘brighter’ than soft tissue, they are often not easily distinguishable from the surrounding tissue. Therefore, US imaging methods aimed at segmenting bone surfaces need enhancement in image contrast prior to segmentation to improve the quality of the detected bone surface. In this paper, we present a novel acquisition/processing technique for bone surface enhancement in US images. Inspired by elastography and Doppler imaging methods, this technique takes advantage of the difference between the mechanical and acoustic properties of bones and those of soft tissues to make the bone surface more easily distinguishable in US images. The objective of this technique is to facilitate US-based bone segmentation methods and improve the accuracy of their outcomes. The newly proposed technique is tested both in in vitro and in vivo experiments. The results of these preliminary experiments suggest that the use of the proposed technique has the potential to significantly enhance the detectability of bone surfaces in noisy ultrasound images.

  9. Re-examining mortality sources and population trends in a declining seabird: using Bayesian methods to incorporate existing information and new data.

    Directory of Open Access Journals (Sweden)

    Tim Reid

    Full Text Available The population of flesh-footed shearwaters (Puffinus carneipes breeding on Lord Howe Island was shown to be declining from the 1970's to the early 2000's. This was attributed to destruction of breeding habitat and fisheries mortality in the Australian Eastern Tuna and Billfish Fishery. Recent evidence suggests these impacts have ceased; presumably leading to population recovery. We used Bayesian statistical methods to combine data from the literature with more recent, but incomplete, field data to estimate population parameters and trends. This approach easily accounts for sources of variation and uncertainty while formally incorporating data and variation from different sources into the estimate. There is a 70% probability that the flesh-footed shearwater population on Lord Howe continued to decline during 2003-2009, and a number of possible reasons for this are suggested. During the breeding season, road-based mortality of adults on Lord Howe Island is likely to result in reduced adult survival and there is evidence that breeding success is negatively impacted by marine debris. Interactions with fisheries on flesh-footed shearwater winter grounds should be further investigated.

  10. Demonstration of tyrosinase in the vitiligo skin of human beings by a sensitive fluorometric method as well as by 14C(U)-L-tyrosine incorporation into melanin

    Energy Technology Data Exchange (ETDEWEB)

    Husain, I.; Vijayan, E.; Ramaiah, A.; Pasricha, J.S.; Madan, N.C.

    1982-03-01

    Tyrosinase activity (Monophenol, dihydroxyphenylalanine: oxygen oxidoreductase EC 1.14.18.1) in vitiligo and normal epidermal homogenates of skin from human beings was measured by estimating beta 3,4-dihydroxyphenylalanine (dopa) by a highly sensitive fluorometric method described in this paper. The tyrosine activity in the vitiligo skin was about 4 to 37% of corresponding normal skin. The activity of tyrosinase in normal human skin from different individuals and from different regions of the body was in the range of 4 to 140 picomoles of beta 3,4-dihydroxyphenylalanine formed per min/mg protein of epidermal homogenate. The enzyme from vitiligo and normal skin was severely inhibited by substance(s) of low molecular weight. The enzyme exhibits a lag of about 4 hr in the absence of added beta 3,4-dihydroxyphenylalanine and 1 hr in presence of 5 microM dopa. Tyrosinase from the normal and vitiligo skin was inhibited by excess concentration of tyrosine. The homogenates from vitiligo skin could synthesize melanin from C14(U)-L-Tyrosine. The rate of tyrosine incorporation into melanin by the epidermal homogenates is increased by 3,4-dihydroxyphenylalanine (dopa) disproportionate to its effect on tyrosinase activity. Based on the data presented in this paper it is concluded that melanocytes are present in the vitiligo skin. A tentative hypothesis is put forward to explain the lack of melanin synthesis by the vitiligo skin under in vivo conditions, although melanocytes are present.

  11. Comparison of spray congealing and melt emulsification methods for the incorporation of the water-soluble salbutamol sulphate in lipid microparticles.

    Science.gov (United States)

    Scalia, Santo; Traini, Daniela; Young, Paul M; Di Sabatino, Marcello; Passerini, Nadia; Albertini, Beatrice

    2013-02-01

    Salbutamol sulphate is widely used as bronchodilator for the treatment of asthma. Its use is limited by the relatively short duration of action and hence sustained delivery of salbutamol sulphate offers potential benefits to patients. This study explores the preparation of lipid microparticles (LMs) as biocompatible carrier for the prolonged release of salbutamol sulphate. The LMs were produced using different lipidic materials and surfactants, by classical melt emulsification-based methods (oil-in-water and water-in-oil-in-water emulsions) and the spray congealing technique. For the LMs obtained by melt emulsification a lack of release modulation was observed. On the other hand, the sustained release of salbutamol sulphate was achieved with glyceryl behenate microparticles prepared by spray congealing. These LMs were characterized by scanning electron microscopy, X-ray diffractometry and differential scanning calorimetry. The drug loading was 4.72% (w/w). The particle size distribution measured by laser diffraction and electrical zone sensing was represented by a volume median diameter (Dv(50)) of 51.7-71.4 µm. Increasing the atomization air pressure from 4 to 8 bar produced a decrease of the Dv(50) to 12.7-17.5 µm. Incorporation of the hydrophilic salbutamol sulphate into LMs with sustained release characteristics was achieved by spray congealing.

  12. Incorporation of Mn2+ into CdSe quantum dots by chemical bath co-deposition method for photovoltaic enhancement of quantum dot-sensitized solar cells.

    Science.gov (United States)

    Zhang, Chenguang; Liu, Shaowen; Liu, Xingwei; Deng, Fei; Xiong, Yan; Tsai, Fang-Chang

    2018-03-01

    A photoelectric conversion efficiency (PCE) of 4.9% was obtained under 100 mW cm -2 illumination by quantum-dot-sensitized solar cells (QDSSCs) using a CdS/Mn : CdSe sensitizer. CdS quantum dots (QDs) were deposited on a TiO 2 mesoporous oxide film by successive ionic layer absorption and reaction. Mn 2+ doping into CdSe QDs is an innovative and simple method-chemical bath co-deposition, that is, mixing the Mn ion source with CdSe precursor solution for Mn : CdSe QD deposition. Compared with the CdS/CdSe sensitizer without Mn 2+ incorporation, the PCE was increased from 3.4% to 4.9%. The effects of Mn 2+ doping on the chemical, physical and photovoltaic properties of the QDSSCs were investigated by energy dispersive spectrometry, absorption spectroscopy, photocurrent density-voltage characteristics and electrochemical impedance spectroscopy. Mn-doped CdSe QDs in QDSSCs can obtain superior light absorption, faster electron transport and slower charge recombination than CdSe QDs.

  13. Biomimetic coating of organic polymers with a protein-functionalized layer of calcium phosphate: the surface properties of the carrier influence neither the coating characteristics nor the incorporation mechanism or release kinetics of the protein.

    Science.gov (United States)

    Wu, Gang; Liu, Yuelian; Iizuka, Tateyuki; Hunziker, Ernst B

    2010-12-01

    Polymers that are used in clinical practice as bone-defect-filling materials possess many essential qualities, such as moldability, mechanical strength and biodegradability, but they are neither osteoconductive nor osteoinductive. Osteoconductivity can be conferred by coating the material with a layer of calcium phosphate, which can be rendered osteoinductive by functionalizing it with an osteogenic agent. We wished to ascertain whether the morphological and physicochemical characteristics of unfunctionalized and bovine-serum-albumin (BSA)-functionalized calcium-phosphate coatings were influenced by the surface properties of polymeric carriers. The release kinetics of the protein were also investigated. Two sponge-like materials (Helistat® and Polyactive®) and two fibrous ones (Ethisorb™ and poly[lactic-co-glycolic acid]) were tested. The coating characteristics were evaluated using state-of-the-art methodologies. The release kinetics of BSA were monitored spectrophotometrically. The characteristics of the amorphous and the crystalline phases of the coatings were not influenced by either the surface chemistry or the surface geometry of the underlying polymer. The mechanism whereby BSA was incorporated into the crystalline layer and the rate of release of the truly incorporated depot were likewise unaffected by the nature of the polymeric carrier. Our biomimetic coating technique could be applied to either spongy or fibrous bone-defect-filling organic polymers, with a view to rendering them osteoconductive and osteoinductive.

  14. Evaluating the Usability and Perceived Impact of an Electronic Medical Record Toolkit for Atrial Fibrillation Management in Primary Care: A Mixed-Methods Study Incorporating Human Factors Design.

    Science.gov (United States)

    Tran, Kim; Leblanc, Kori; Valentinis, Alissia; Kavanagh, Doug; Zahr, Nina; Ivers, Noah M

    2016-02-17

    Atrial fibrillation (AF) is a common and preventable cause of stroke. Barriers to reducing stroke risk through appropriate prescribing have been identified at the system, provider, and patient levels. To ensure a multifaceted initiative to address these barriers is effective, it is essential to incorporate user-centered design to ensure all intervention components are optimized for users. To test the usability of an electronic medical record (EMR) toolkit for AF in primary care with the goal of further refining the intervention to meet the needs of primary care clinicians. An EMR-based toolkit for AF was created and optimized through usability testing and iterative redesign incorporating a human factors approach. A mixed-methods pilot study consisting of observations, semi-structured interviews, and surveys was conducted to examine usability and perceived impact on patient care and workflow. A total of 14 clinicians (13 family physicians and 1 nurse practitioner) participated in the study. Nine iterations of the toolkit were created in response to feedback from clinicians and the research team; interface-related changes were made, additional AF-related resources were added, and functionality issues were fixed to make the toolkit more effective. After improvements were made, clinicians expressed that the toolkit improved accessibility to AF-related information and resources, served as a reminder for guideline-concordant AF management, and was easy to use. Most clinicians intended to continue using the toolkit for patient care. With respect to impact on care, clinicians believed the toolkit increased the thoroughness of their assessments for patients with AF and improved the quality of AF-related care received by their patients. The positive feedback surrounding the EMR toolkit for AF and its perceived impact on patient care can be attributed to the adoption of a user-centered design that merged clinically important information about AF management with user needs

  15. An automatic rat brain extraction method based on a deformable surface model.

    Science.gov (United States)

    Li, Jiehua; Liu, Xiaofeng; Zhuo, Jiachen; Gullapalli, Rao P; Zara, Jason M

    2013-08-15

    The extraction of the brain from the skull in medical images is a necessary first step before image registration or segmentation. While pre-clinical MR imaging studies on small animals, such as rats, are increasing, fully automatic imaging processing techniques specific to small animal studies remain lacking. In this paper, we present an automatic rat brain extraction method, the Rat Brain Deformable model method (RBD), which adapts the popular human brain extraction tool (BET) through the incorporation of information on the brain geometry and MR image characteristics of the rat brain. The robustness of the method was demonstrated on T2-weighted MR images of 64 rats and compared with other brain extraction methods (BET, PCNN, PCNN-3D). The results demonstrate that RBD reliably extracts the rat brain with high accuracy (>92% volume overlap) and is robust against signal inhomogeneity in the images. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Advancing Methods for Estimating Soil Nitrous Oxide Emissions by Incorporating Freeze-Thaw Cycles into a Tier 3 Model-Based Assessment

    Science.gov (United States)

    Ogle, S. M.; DelGrosso, S.; Parton, W. J.

    2017-12-01

    Soil nitrous oxide emissions from agricultural management are a key source of greenhouse gas emissions in many countries due to the widespread use of nitrogen fertilizers, manure amendments from livestock production, planting legumes and other practices that affect N dynamics in soils. In the United States, soil nitrous oxide emissions have ranged from 250 to 280 Tg CO2 equivalent from 1990 to 2015, with uncertainties around 20-30 percent. A Tier 3 method has been used to estimate the emissions with the DayCent ecosystem model. While the Tier 3 approach is considerably more accurate than IPCC Tier 1 methods, there is still the possibility of biases in emission estimates if there are processes and drivers that are not represented in the modeling framework. Furthermore, a key principle of IPCC guidance is that inventory compilers estimate emissions as accurately as possible. Freeze-thaw cycles and associated hot moments of nitrous oxide emissions are one of key drivers influencing emissions in colder climates, such as the cold temperate climates of the upper Midwest and New England regions of the United States. Freeze-thaw activity interacts with management practices that are increasing N availability in the plant-soil system, leading to greater nitrous oxide emissions during transition periods from winter to spring. Given the importance of this driver, the DayCent model has been revised to incorproate freeze-thaw cycles, and the results suggests that including this driver can significantly modify the emissions estimates in cold temperate climate regions. Consequently, future methodological development to improve estimation of nitrous oxide emissions from soils would benefit from incorporating freeze-thaw cycles into the modeling framework for national territories with a cold climate.

  17. An Improved Local Gradient Method for Sea Surface Wind Direction Retrieval from SAR Imagery

    Directory of Open Access Journals (Sweden)

    Lizhang Zhou

    2017-06-01

    Full Text Available Sea surface wind affects the fluxes of energy, mass and momentum between the atmosphere and ocean, and therefore regional and global weather and climate. With various satellite microwave sensors, sea surface wind can be measured with large spatial coverage in almost all-weather conditions, day or night. Like any other remote sensing measurements, sea surface wind measurement is also indirect. Therefore, it is important to develop appropriate wind speed and direction retrieval models for different types of microwave instruments. In this paper, a new sea surface wind direction retrieval method from synthetic aperture radar (SAR imagery is developed. In the method, local gradients are computed in frequency domain by combining the operation of smoothing and computing local gradients in one step to simplify the process and avoid the difference approximation. This improved local gradients (ILG method is compared with the traditional two-dimensional fast Fourier transform (2D FFT method and local gradients (LG method, using interpolating wind directions from the European Centre for Medium-Range Weather Forecast (ECMWF reanalysis data and the Cross-Calibrated Multi-Platform (CCMP wind vector product. The sensitivities to the salt-and-pepper noise, the additive noise and the multiplicative noise are analyzed. The ILG method shows a better performance of retrieval wind directions than the other two methods.

  18. Evaluating polymer degradation with complex mixtures using a simplified surface area method.

    Science.gov (United States)

    Steele, Kandace M; Pelham, Todd; Phalen, Robert N

    2017-09-01

    Chemical-resistant gloves, designed to protect workers from chemical hazards, are made from a variety of polymer materials such as plastic, rubber, and synthetic rubber. One material does not provide protection against all chemicals, thus proper polymer selection is critical. Standardized testing, such as chemical degradation tests, are used to aid in the selection process. The current methods of degradation ratings based on changes in weight or tensile properties can be expensive and data often do not exist for complex chemical mixtures. There are hundreds of thousands of chemical products on the market that do not have chemical resistance data for polymer selection. The method described in this study provides an inexpensive alternative to gravimetric analysis. This method uses surface area change to evaluate degradation of a polymer material. Degradation tests for 5 polymer types against 50 complex mixtures were conducted using both gravimetric and surface area methods. The percent change data were compared between the two methods. The resulting regression line was y = 0.48x + 0.019, in units of percent, and the Pearson correlation coefficient was r = 0.9537 (p ≤ 0.05), which indicated a strong correlation between percent weight change and percent surface area change. On average, the percent change for surface area was about half that of the weight change. Using this information, an equivalent rating system was developed for determining the chemical degradation of polymer gloves using surface area.

  19. Standard Test Method for Measuring Heat Flux Using Surface-Mounted One-Dimensional Flat Gages

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method describes the measurement of the net heat flux normal to a surface using flat gages mounted onto the surface. Conduction heat flux is not the focus of this standard. Conduction applications related to insulation materials are covered by Test Method C 518 and Practices C 1041 and C 1046. The sensors covered by this test method all use a measurement of the temperature difference between two parallel planes normal to the surface to determine the heat that is exchanged to or from the surface in keeping with Fourier’s Law. The gages operate by the same principles for heat transfer in either direction. 1.2 This test method is quite broad in its field of application, size and construction. Different sensor types are described in detail in later sections as examples of the general method for measuring heat flux from the temperature gradient normal to a surface (1). Applications include both radiation and convection heat transfer. The gages have broad application from aerospace to biomedical en...

  20. Method using laser irradiation for the production of atomically clean crystalline silicon and germanium surfaces

    Science.gov (United States)

    Ownby, Gary W.; White, Clark W.; Zehner, David M.

    1981-01-01

    This invention relates to a new method for removing surface impurities from crystalline silicon or germanium articles, such as off-the-shelf p- or n-type wafers to be doped for use as junction devices. The principal contaminants on such wafers are oxygen and carbon. The new method comprises laser-irradiating the contaminated surface in a non-reactive atmosphere, using one or more of Q-switched laser pulses whose parameters are selected to effect melting of the surface without substantial vaporization thereof. In a typical application, a plurality of pulses is used to convert a surface region of an off-the-shelf silicon wafer to an automatically clean region. This can be accomplished in a system at a pressure below 10.sup.-8 Torr, using Q-switched ruby-laser pulses having an energy density in the range of from about 60 to 190 MW/cm.sup.2.

  1. The impact of accelerometer mounting methods on the level of vibrations recorded at ground surface

    Directory of Open Access Journals (Sweden)

    Krzysztof Czech

    2014-08-01

    Full Text Available The paper presents the results of field research based on the measurements of accelerations recorded at ground surface. The source of the vibration characterized by high repetition rate of pulse parameters was light falling weight deflectometer ZFG-01. Measurements of vibrations have been carried out using top quality high-precision measuring system produced by Brüel&Kiær. Accelerometers were mounted on a sandy soil surface at the measuring points located radially at 5-m and 10-m distances from the source of vibration. The paper analyses the impact that the method of mounting accelerometers on the ground has on the level of the recorded values of accelerations of vibrations. It has been shown that the method of attaching the sensor to the surface of the ground is crucial for the credibility of the performed measurements.[b]Keywords[/b]: geotechnics, surface vibrations, ground, vibration measurement

  2. Construction of super - hydrophobic copper alloy surface by one - step mixed solution immersion method

    Science.gov (United States)

    Gu, Qiang; Chen, Ying; Chen, Dong; Zhang, Zeting

    2018-01-01

    This paper presents a method for preparing a super hydrophobic surface with a fast, simple, low-cost, one-step reaction by immersing copper alloy in an ethanol solution containing silver nitrate and myristic acid. The effects of reaction time, reaction temperature, reactant concentration and reaction time on the wettability of the material were studied. The surface wettability, appearance, chemical composition, durability and chemical stability of the prepared samples was measured by water contact angle (CA), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results show that when the reaction time is only 10min, the surface WCA of the prepared material can reach 154.9. This study provides an effective method for the rapid preparation of stable super hydrophobic surfaces.

  3. Super-hydrophobic surfaces from a simple coating method: a bionic nanoengineering approach

    International Nuclear Information System (INIS)

    Liu Yuyang; Chen Xianqiong; Xin, J H

    2006-01-01

    Inspired by the self-cleaning behaviour of lotus leaves in nature, we developed a simple coating method that can facilitate the bionic creation of super-hydrophobic surfaces on various substrates, thus providing a feasible way of fabricating super-hydrophobic surfaces for civil and industrial applications. Micro-nanoscale binary structured composite particles of silica/fluoropolymer were prepared using an emulsion-mediated sol-gel process, and then these composite particles were applied to various substrates to mimic the surface microstructures of lotus leaves. Super-hydrophobic surfaces with a water contact angle larger than 150 deg. are obtained, and these super-hydrophobic surfaces are expected to have potential applications for rusting-resistant, anti-fog and self-cleaning treatments

  4. Analysis of WEDM Process Parameters on Surface Roughness and Kerf using Taguchi Method

    Directory of Open Access Journals (Sweden)

    Asfana Banu

    2017-12-01

    Full Text Available In obtaining the best quality of engineering parts, the quality of machined surface plays an essential role. The fatigue strength, wear resistance, and corrosion of workpiece are some of the aspects of the qualities that can be improved. This paper investigates the effect of wire electrical discharge machining (WEDM process parameters on surface roughness and kerf on stainless steel using distilled water as dielectric fluid and brass wire as tool electrode. The selected process parameters are voltage open, wire speed, wire tension, voltage gap, and off time. Empirical models using Taguchi method were developed for the estimation of surface roughness and kerf. The analysis revealed that off time has major influence on surface roughness and kerf. The optimum machining parameters for minimum surface roughness and kerf were found to be 10 V open voltage, 2.84 µs off time, 12 m/min wire speed, 6.3 N wire tension, and 54.91 V voltage gap.

  5. Coupling characteristics of dielectric-loaded surface plasmon polariton waveguides: a simple method of analysis.

    Science.gov (United States)

    Srivastava, Triranjita; Kumar, Arun

    2009-11-01

    A simple method to obtain the coupling characteristics of a directional coupler consisting of two dielectric-loaded surface plasmon polariton waveguides is reported. The method is found to give accurate results in comparison with the widely used effective index method. Theoretical results are also found to match excellently with recently reported measurements on coupling lengths in such waveguides [Opt. Lett.34, 310 (2009)OPLEDP0146-959210.1364/OL.34.000310].

  6. Measurement of the body surface temperature by the method of laser photothermal radiometry

    International Nuclear Information System (INIS)

    Skvortsov, L A; Kirillov, V M

    2003-01-01

    The specific features of contactless measurements of the body surface temperature by the method of repetitively pulsed laser photothermal radiometry are considered and the requirements to the parameters of the laser and measurement scheme are formulated. The sensitivity of the method is estimated. The advantages of laser photothermal radiometry over the conventional passive radiometric method are discussed. (laser applications and other topics in quantum electronics)

  7. Distinguishing metal bioconcentration from particulate matter in moss tissue: testing methods of removing particles attached to the moss surface.

    Science.gov (United States)

    Spagnuolo, V; Giordano, S; Pérez-Llamazares, A; Ares, A; Carballeira, A; Fernández, J A; Aboal, J R

    2013-10-01

    Accurate differentiation of the proportion of bioconcentrated metals (i.e. incorporated into cells) and the proportion that is not bioconcentrated (i.e. adsorbed at the surface) would lead to a better understanding of the uptake processes and would represent an advance in the use of mosses as biomonitors. Traditionally the methods used to remove contaminants that are not bioconcentrated were to wash the plant material with water or to apply the sequential elution technique, but nowadays both options are considered inaccurate for these purposes. The remaining possibilities are to clean the moss samples with a nitrogen jet or by power ultrasound. Samples of terrestrial moss Pseudoscleropodium purum (Hewd.) Fleisch. were collected from five sampling stations. Different nitrogen jet cleaning procedures and ultrasound cleaning procedures were applied to the mosses. To determine whether any of the treatments altered the membrane integrity of the moss samples, the concentrations of K were determined. The shoots were observed under a scanning electron microscope, and the size and number of particles were determined. Nitrogen jet cleaning was determined to be unacceptable because it damaged the phyllids and/or altered the membrane permeability and did not eliminate the particles from the moss surface. Moreover, ultrasound cleaning treatment should also discarded because of the loss of extracellular metals that are transferred to the water in which the moss is cleaned. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. A Numerical Method for Predicting Rayleigh Surface Wave Velocity in Anisotropic Crystals (Postprint)

    Science.gov (United States)

    2017-09-05

    crystal symmetries and directions of propagation, and the advantages and disadvantages are dis- cussed. An alternative method of finding the RSW velocity...efficient in calculating RSW velocity curves in all cases. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license ...http://creativecommons.org/ licenses /by-nc-nd/4.0/). 1. Introduction Surface acoustic waves (SAW) such as Rayleigh surface waves (RSW) are important in

  9. CMC-1 Surfaces in Hyperbolic 3-space using the Bianchi-Calo method

    OpenAIRE

    de Lima, Levi Lopes; Roitman, Pedro

    2001-01-01

    In this note we present a method for constructing CMC-1 surfaces in hyperbolic 3-space $\\bfH^3(-1)$ in terms of holomorphic data first introduced in Bianchi's Lezioni di Geometria Differenziale of 1927, therefore predating by many years the modern approaches due to Bryant, Small and others. Besides its obvious historical interest, this note aims to complement Bianchi's analysis by deriving explicit formulae for CMC-1 surfaces and comparing the various approaches encountered in the literature.

  10. Constant mean curvature one surfaces in hyperbolic 3-space using the Bianchi-Calò method

    OpenAIRE

    LIMA LEVI L. DE; ROITMAN PEDRO

    2002-01-01

    In this note we present a method for constructing constant mean curvature on surfaces in hyperbolic 3-space in terms of holomorphic data first introduced in Bianchi's Lezioni di Geometria Differenziale of 1927, therefore predating by many years the modern approaches due to Bryant, Small and others. Besides its obvious historical interest, this note aims to complement Bianchi's analysis by deriving explicit formulae for CMC-1 surfaces and comparing the various approaches encountered in the lit...

  11. An improved extraction method for surface dosage of insecticides on treated textile fabrics.

    Science.gov (United States)

    Dieval, Florence; Bouyer, Jérémy; Fafet, Jean-François

    2017-01-04

    Tens of millions of people live in mosquito-infested regions and controlling mosquito-borne diseases is one of the major interventions aimed at alleviating poverty worldwide. The use of insecticide-treated textiles is one of the most widespread control measures. This includes bed nets, battle clothing or, more generally, textiles use for clothing. These textiles are generally treated with permethrin as active ingredient, which is dosed after extraction of the active molecule present throughout the fabric (measured in mg permethrin/g of fabric) and does not take the effective concentration on the textile surfaces into account. The objective of this study was to propose an improved dosage method that enables measurement of the bioavailable or effective part of active ingredients on the surface of textile treated with insecticides. The proposed method relies on mechanical extraction of active molecules on the surface of the textile in direct contact with either the skin or with the targeted arthropod. The results showed that the amount of permethrin measured using the current method is about 200 times higher than the effective surface concentration of the insecticide. In addition, the type of weave or knit influences the effective concentrations of permethrin on the surface of the textile. With the current dosage method, the variation in the concentration of permethrin depending on the type of weave is maximum 8%, whereas with the proposed method, it varies by about 50%. These results were confirmed by bioassays, in which the type of weave significantly affected (p fabrics is directly correlated with the effective concentration of insecticide on the textile surface, which can be quantified using the method proposed. This improved method could be used to redefine the limits of actual concentrations of active substance after assessment of the bioefficacy of the treatment and the risk to human health. Further, it enables assessments of the kinetics of insecticide

  12. Increased Surface Roughness in Polydimethylsiloxane Films by Physical and Chemical Methods

    Directory of Open Access Journals (Sweden)

    Jorge Nicolás Cabrera

    2017-08-01

    Full Text Available Two methods, the first physical and the other chemical, were investigated to modify the surface roughness of polydimethylsiloxane (PDMS films. The physical method consisted of dispersing multi-walled carbon nanotubes (MWCNTs and magnetic cobalt ferrites (CoFe2O4 prior to thermal cross-linking, and curing the composite system in the presence of a uniform magnetic field H. The chemical method was based on exposing the films to bromine vapours and then UV-irradiating. The characterizing techniques included scanning electron microscopy (SEM, energy-dispersive spectroscopy (EDS, Fourier transform infrared (FTIR spectroscopy, optical microscopy, atomic force microscopy (AFM and magnetic force microscopy (MFM. The surface roughness was quantitatively analyzed by AFM. In the physical method, the random dispersion of MWCNTs (1% w/w and magnetic nanoparticles (2% w/w generated a roughness increase of about 200% (with respect to PDMS films without any treatment, but that change was 400% for films cured in the presence of H perpendicular to the surface. SEM, AFM and MFM showed that the magnetic particles always remained attached to the carbon nanotubes, and the effect on the roughness was interpreted as being due to a rupture of dispersion randomness and a possible induction of structuring in the direction of H. In the chemical method, the increase in roughness was even greater (1000%. Wells were generated with surface areas that were close to 100 μm2 and depths of up to 500 nm. The observations of AFM images and FTIR spectra were in agreement with the hypothesis of etching by Br radicals generated by UV on the polymer chains. Both methods induced important changes in the surface roughness (the chemical method generated the greatest changes due to the formation of surface wells, which are of great importance in superficial technological processes.

  13. Investigation of KDP crystal surface based on an improved bidimensional empirical mode decomposition method

    Science.gov (United States)

    Lu, Lei; Yan, Jihong; Chen, Wanqun; An, Shi

    2018-03-01

    This paper proposed a novel spatial frequency analysis method for the investigation of potassium dihydrogen phosphate (KDP) crystal surface based on an improved bidimensional empirical mode decomposition (BEMD) method. Aiming to eliminate end effects of the BEMD method and improve the intrinsic mode functions (IMFs) for the efficient identification of texture features, a denoising process was embedded in the sifting iteration of BEMD method. With removing redundant information in decomposed sub-components of KDP crystal surface, middle spatial frequencies of the cutting and feeding processes were identified. Comparative study with the power spectral density method, two-dimensional wavelet transform (2D-WT), as well as the traditional BEMD method, demonstrated that the method developed in this paper can efficiently extract texture features and reveal gradient development of KDP crystal surface. Furthermore, the proposed method was a self-adaptive data driven technique without prior knowledge, which overcame shortcomings of the 2D-WT model such as the parameters selection. Additionally, the proposed method was a promising tool for the application of online monitoring and optimal control of precision machining process.

  14. Monitoring of biofilm formation on different material surfaces of medical devices using hyperspectral imaging method

    Science.gov (United States)

    Kim, Do-Hyun; Kim, Moon S.; Hwang, Jeeseong

    2012-03-01

    Contamination of the inner surface of indwelling (implanted) medical devices by microbial biofilm is a serious problem. Some microbial bacteria such as Escherichia coli form biofilms that lead to potentially lifethreatening infections. Other types of medical devices such as bronchoscopes and duodenoscopes account for the highest number of reported endoscopic infections where microbial biofilm is one of the major causes for these infections. We applied a hyperspectral imaging method to detect biofilm contamination on the surface of several common materials used for medical devices. Such materials include stainless steel, titanium, and stainless-steeltitanium alloy. Potential uses of hyperspectral imaging technique to monitor biofilm attachment to different material surfaces are discussed.

  15. Broadband antireflective silicon carbide surface produced by cost-effective method

    DEFF Research Database (Denmark)

    Argyraki, Aikaterini; Ou, Yiyu; Ou, Haiyan

    2013-01-01

    A cost-effective method for fabricating antireflective subwavelength structures on silicon carbide is demonstrated. The nanopatterning is performed in a 2-step process: aluminum deposition and reactive ion etching. The effect, of the deposited aluminum film thickness and the reactive ion etching...... conditions, on the average surface reflectance and nanostructure landscape have been investigated systematically. The average reflectance of silicon carbide surface is significantly suppressed from 25.4% to 0.05%, under the optimal experimental conditions, in the wavelength range of 390-784 nm. The presence...... of stochastic nanostructures also changes the wetting properties of silicon carbide surface from hydrophilic (47°) to hydrophobic (108°)....

  16. Method for selective immobilization of macromolecules on self assembled monolayer surfaces

    Science.gov (United States)

    Laskin, Julia [Richland, WA; Wang, Peng [Billerica, MA

    2011-11-29

    Disclosed is a method for selective chemical binding and immobilization of macromolecules on solid supports in conjunction with self-assembled monolayer (SAM) surfaces. Immobilization involves selective binding of peptides and other macromolecules to SAM surfaces using reactive landing (RL) of mass-selected, gas phase ions. SAM surfaces provide a simple and convenient platform for tailoring chemical properties of a variety of substrates. The invention finds applications in biochemistry ranging from characterization of molecular recognition events at the amino acid level and identification of biologically active motifs in proteins, to development of novel biosensors and substrates for stimulated protein and cell adhesion.

  17. A Survey on Methods for Reconstructing Surfaces from Unorganized Point Sets

    Directory of Open Access Journals (Sweden)

    Vilius Matiukas

    2011-08-01

    Full Text Available This paper addresses the issue of reconstructing and visualizing surfaces from unorganized point sets. These can be acquired using different techniques, such as 3D-laser scanning, computerized tomography, magnetic resonance imaging and multi-camera imaging. The problem of reconstructing surfaces from their unorganized point sets is common for many diverse areas, including computer graphics, computer vision, computational geometry or reverse engineering. The paper presents three alternative methods that all use variations in complementary cones to triangulate and reconstruct the tested 3D surfaces. The article evaluates and contrasts three alternatives.Article in English

  18. Effective UV/Ozone irradiation method for decontamination of hydroxyapatite surfaces

    Directory of Open Access Journals (Sweden)

    Keisuke Yasuda

    2017-08-01

    Full Text Available The purpose of this study was to establish whether UV/ozone (O3 irradiation method can effectively decontaminate hydroxyapatite surfaces, including those modified by the treatment with 30% phosphoric acid solution through morphological and chemical surface analyses (surface roughness, X-ray photoelectron spectroscopy and wettability, and to evaluate the in vitro response of osteoblast-like MC3T3-E1 cells to the modified hydroxyapatite surface decontaminated via this method. The amount of carbon and the contact angle of hydroxyapatite surfaces were significantly decreased by UV/O3 irradiation that lasted for ≥ 5 and ≥ 3 min, respectively (P 0.05. MC3T3-E1 cell proliferation, differentiation (as assessed by relative ALP and OCN mRNA levels, and mineralisation were significantly promoted on irradiated surfaces (P < 0.05. These findings show that UV/O3 irradiation for ≥ 5 min significantly decontaminated H3PO4-modified hydroxyapatite surface, improved its wettability, and facilitated osteoblast growth and function.

  19. A new experimental method for determining liquid density and surface tension

    Science.gov (United States)

    Chou, Kjo-Chih; Hu, Jian-Hong

    1991-02-01

    A summary concerning the measurement of liquid density relying on the Archimedes principle has been presented, based on which a new effective method with a specially designed bob for determining liquid density has been suggested. The application of this method to ethyl alcohol solution and liquid glycerol, as well as a theoretical error analysis, shows that this new method is significant, because not only can it simplify the procedure of measurement but it can also offer more precise results. Besides, this method can further provide surface tension or contact angle simultaneously. It is expected that this new method will find its application in hightemperature melts.

  20. Source signature estimation from multimode surface waves via mode-separated virtual real source method

    Science.gov (United States)

    Gao, Lingli; Pan, Yudi

    2018-02-01

    The correct estimation of the seismic source signature is crucial to exploration geophysics. Based on seismic interferometry, the virtual real source (VRS) method provides a model-independent way for source signature estimation. However, when encountering multimode surface waves, which are commonly seen in the shallow seismic survey, strong spurious events appear in seismic interferometric results. These spurious events introduce errors in the virtual-source recordings, and reduce the accuracy of the source signature estimated by the VRS method. In order to estimate a correct source signature from multimode surface waves, we propose a mode-separated VRS method. In this method, multimode surface waves are mode separated before seismic interferometry. Virtual-source recordings are then obtained by applying seismic interferometry to each mode individually. Therefore, artefacts caused by cross-mode correlation are excluded in the virtual-source recordings and the estimated source signatures. A synthetic example showed that a correct source signature can be estimated with the proposed method, while strong spurious oscillation occurs in the estimated source signature if we do not apply mode separation first. We also applied the proposed method to a field example, which verified its validity and effectiveness in estimating seismic source signature from shallow seismic shot gathers containing multimode surface waves.

  1. Surface analysis methods of biomaterials used in oral surgery: literature review.

    Science.gov (United States)

    Suba, Csongor; Velich, Norbert; Turi, Csaba; Szabó, György

    2005-01-01

    Titanium is the most frequently used biomaterial in oral surgery because of its positive physical and chemical properties. Clinical studies proved that the properties of titanium can be improved by surface modification techniques. To study the surface of biomaterials, the positive effects of the coatings, the response of the organism (corrosion resistance, physical and chemical stability, the thickness of various coatings, biocompatibility), one must choose and use the adequate analytical method for one's goal. In this article, the authors present the most frequently used analytical methods for the study of the surface morphology and composition of biomaterials. Also, they outline the advantages and disadvantages of specific analytical methods and the field where they are used.

  2. Robust Optimization Design for Turbine Blade-Tip Radial Running Clearance using Hierarchically Response Surface Method

    Science.gov (United States)

    Zhiying, Chen; Ping, Zhou

    2017-11-01

    Considering the robust optimization computational precision and efficiency for complex mechanical assembly relationship like turbine blade-tip radial running clearance, a hierarchically response surface robust optimization algorithm is proposed. The distribute collaborative response surface method is used to generate assembly system level approximation model of overall parameters and blade-tip clearance, and then a set samples of design parameters and objective response mean and/or standard deviation is generated by using system approximation model and design of experiment method. Finally, a new response surface approximation model is constructed by using those samples, and this approximation model is used for robust optimization process. The analyses results demonstrate the proposed method can dramatic reduce the computational cost and ensure the computational precision. The presented research offers an effective way for the robust optimization design of turbine blade-tip radial running clearance.

  3. The Closest Point Method and Multigrid Solvers for Elliptic Equations on Surfaces

    KAUST Repository

    Chen, Yujia

    2015-01-01

    © 2015 Society for Industrial and Applied Mathematics. Elliptic partial differential equations are important from both application and analysis points of view. In this paper we apply the closest point method to solve elliptic equations on general curved surfaces. Based on the closest point representation of the underlying surface, we formulate an embedding equation for the surface elliptic problem, then discretize it using standard finite differences and interpolation schemes on banded but uniform Cartesian grids. We prove the convergence of the difference scheme for the Poisson\\'s equation on a smooth closed curve. In order to solve the resulting large sparse linear systems, we propose a specific geometric multigrid method in the setting of the closest point method. Convergence studies in both the accuracy of the difference scheme and the speed of the multigrid algorithm show that our approaches are effective.

  4. A numerical method for predicting Rayleigh surface wave velocity in anisotropic crystals

    Science.gov (United States)

    Cherry, Matthew R.; Sathish, Shamachary; Grandhi, Ramana

    2017-12-01

    A numerical method was developed for calculating the Rayleigh Surface Wave (RSW) velocity in arbitrarily oriented single crystals in 360 degrees of propagation. This method relies on the results from modern analysis of RSW behavior with the Stroh formalism to restrict the domain in which to search for velocities by first calculating the limiting velocity. This extension of existing numerical methods also leads to a natural way of determining both the existence of the RSW as well as the possibility of encountering a pseudo-surface wave. Furthermore, the algorithm is applied to the calculation of elastic properties from measurement of the surface wave velocity in multiple different directions on a single crystal sample. The algorithm was tested with crystal symmetries and single crystal elastic moduli from literature. It was found to be very robust and efficient in calculating RSW velocity curves in all cases.

  5. ALE finite volume method for free-surface Bingham plastic fluids with general curvilinear coordinates

    International Nuclear Information System (INIS)

    Nagai, Katsuaki; Ushijima, Satoru

    2010-01-01

    A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.

  6. ALE finite volume method for free-surface Bingham plastic fluids with general curvilinear coordinates

    Science.gov (United States)

    Nagai, Katsuaki; Ushijima, Satoru

    2010-06-01

    A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.

  7. Inverse gas chromatography as a method for determination of surface properties of binding materials

    Science.gov (United States)

    Yu, Jihai; Lu, Xiaolei; Yang, Chunxia; Du, Baoli; Wang, Shuxian; Ye, Zhengmao

    2017-09-01

    Inverse gas chromatography (IGC) is a promising measurement technique for investigating the surface properties of binding materials, which are the major influence element for the adsorption performance of superplasticizer. In this work, using the IGC method, blast furnace slag (BFS), sulphoaluminate cement (SAC) and portland cement (P·O) are employed to systematically evaluate the corresponding dispersive component (γsd), specific surface free energy (γsab), and acid-base properties. The obtained results show that γsd contributes to a major section of the surface free energy in the three binding materials, suggesting they are of a relatively low polarity. Compared to the two kinds of cements, the BFS possesses the highest dispersive and specific surface free energies (the values are 45.01 mJ/m2 and 11.68 mJ/m2, respectively), and also exhibits a wider distribution range of γsd, indicating their surfaces are heterogeneous. For acid-base properties, the results indicate the surfaces of three samples are basic in nature. In addition, the adsorption investigation shows that per unit surface of BFS adsorbs the most superplasticizer molecules, which indicates the higher surface free energies is beneficial to the superplasticizer adsorption.

  8. Analysis of Surface Waves in Saturated Layered Poroelastic Half-Spaces Using the Thin Layer Method

    Science.gov (United States)

    Chai, Huayou; Cui, Yujun; Zhang, Dianji

    2018-03-01

    There are multiple modes of surface waves in saturated layered poroelastic half-spaces. The phase velocity and the attenuation of the modes are frequency dependent. The frequency behaviour of the modes can be studied using the layer transfer, stiffness and the transmission/reflection matrix methods. However, it is very difficult to find the complex roots of the determinants because the entries of the matrices involve the complex exponential functions of the wavenumber and the thickness of layer. To overcome this difficulty, the entries in the matrix are expressed in the form of algebraic functions using the thin layer method. Thus, the eigenvalues and eigenvectors can be easily solved using the matrix decomposition techniques instead of the root-searching ones. Some of the eigenvalues correspond to the wavenumbers of the surface waves, and can be picked out based on the characteristics of the surface waves. The frequency behaviour, variations of the pore pressure and the skeleton's displacements with the depth can be then investigated from the corresponding eigenvalues and eigenvectors, respectively. The method is verified by comparing the analytical and the discrete results in the saturated poroelastic half-space with the permeable surface. The method is applied to appreciate the effects of an impermeable surface on Rayleigh waves (R-waves) and the existence of Stoneley waves in the poroelastic half-space. The frequency behaviour of Rayleigh waves in three typical layered poroelastic half-spaces is also analyzed.

  9. A novel technique for including surface tension in PLIC-VOF methods

    Energy Technology Data Exchange (ETDEWEB)

    Meier, M.; Yadigaroglu, G. [Swiss Federal Institute of Technology, Nuclear Engineering Lab. ETH-Zentrum, CLT, Zurich (Switzerland); Smith, B. [Paul Scherrer Inst. (PSI), Villigen (Switzerland). Lab. for Thermal-Hydraulics

    2002-02-01

    Various versions of Volume-of-Fluid (VOF) methods have been used successfully for the numerical simulation of gas-liquid flows with an explicit tracking of the phase interface. Of these, Piecewise-Linear Interface Construction (PLIC-VOF) appears as a fairly accurate, although somewhat more involved variant. Including effects due to surface tension remains a problem, however. The most prominent methods, Continuum Surface Force (CSF) of Brackbill et al. and the method of Zaleski and co-workers (both referenced later), both induce spurious or 'parasitic' currents, and only moderate accuracy in regards to determining the curvature. We present here a new method to determine curvature accurately using an estimator function, which is tuned with a least-squares-fit against reference data. Furthermore, we show how spurious currents may be drastically reduced using the reconstructed interfaces from the PLIC-VOF method. (authors)

  10. Cheap and fast measuring roughness on big surfaces with an imprint method

    Science.gov (United States)

    Schopf, C.; Liebl, J.; Rascher, R.

    2017-10-01

    Roughness, shape and structure of a surface offer information on the state, shape and surface characteristics of a component. Particularly the roughness of the surface dictates the subsequent polishing of the optical surface. The roughness is usually measured by a white light interferometer, which is limited by the size of the components. Using a moulding method of surfaces that are difficult to reach, an imprint is taken and analysed regarding to roughness and structure. This moulding compound method is successfully used in dental technology. In optical production, the moulding compound method is advantageous in roughness determination in inaccessible spots or on large components (astrological optics). The "replica method" has been around in metal analysis and processing. Film is used in order to take an impression of a surface. Then, it is analysed for structures. In optical production, compound moulding seems advantageous in roughness determination in inaccessible spots or on large components (astrological optics). In preliminary trials, different glass samples with different roughness levels were manufactured. Imprints were taken from these samples (based on DIN 54150 "Abdruckverfahren für die Oberflächenprüfung"). The objective of these feasibility tests was to determine the limits of this method (smallest roughness determinable / highest roughness). The roughness of the imprint was compared with the roughness of the glass samples. By comparing the results, the uncertainty of the measuring method was determined. The spectrum for the trials ranged from rough grind (0.8 μm rms), over finishing grind (0.6 μm rms) to polishing (0.1 μm rms).

  11. New laboratory methods to study tooth surface coverage and interproximal plaque control by dentifrice products.

    Science.gov (United States)

    Xu, Tao; Herles, Susan M; Barnes, Virginia M

    2004-01-01

    To develop and test an in vitro tooth model for use in conjunction with laboratory methods to study interproximal effects and efficacy of dentifrices. The application of the model should offer visual evaluation of dentifrice coverage of the tooth surface, and measure dental plaque control at posterior interdental spaces with a dentifrice. The dentifrice products tested with the model were: Colgate Total 2 in 1 Toothpaste and Mouthwash (CTTM), Colgate Total dentifrice (CTD), and Colgate Regular dentifrice (CRD). Extracted human posterior teeth were disinfected, cleaned, aligned, and mounted in denture acrylic. In the area coverage method, tooth surface coverage and penetration of two different forms of dentifrice products (CTTM and CRD) were compared using digital photography. In the interproximal plaque control method, the teeth were coated with human saliva and incubated anaerobically with a mixture of representative oral bacteria for six hours at 37 degrees C. In vitro dental plaque was assessed after brushing the facial surface with one of the three dentifrice products using a clinical plaque scoring index. The area coverage method demonstrated that both dentifrice products tested covered approximately 70% of the facial tooth surface; the CTTM dentifrice coverage on the lingual tooth surface was significantly higher than the coverage for the CRD dentifrice. With the interproximal plaque control method, in the presence of an active ingredient, the CTTM dentifrice had equivalent efficacy to the CTD dentifrice. Both CTTM and CTD were significantly superior to the CRD for interproximal dental plaque control. Using the developed tooth model, two assessment methods have been shown to have the potential to demonstrate tooth surface coverage, and to assess the potential efficacy of a dentifrice for the control of interproximal dental plaque. This process can indicate potential clinical evaluation of an oral care product, and support clinical findings with controlled

  12. Modified feed-forward neural network structures and combined-function-derivative approximations incorporating exchange symmetry for potential energy surface fitting.

    Science.gov (United States)

    Nguyen, Hieu T T; Le, Hung M

    2012-05-10

    The classical interchange (permutation) of atoms of similar identity does not have an effect on the overall potential energy. In this study, we present feed-forward neural network structures that provide permutation symmetry to the potential energy surfaces of molecules. The new feed-forward neural network structures are employed to fit the potential energy surfaces for two illustrative molecules, which are H(2)O and ClOOCl. Modifications are made to describe the symmetric interchange (permutation) of atoms of similar identity (or mathematically, the permutation of symmetric input parameters). The combined-function-derivative approximation algorithm (J. Chem. Phys. 2009, 130, 134101) is also implemented to fit the neural-network potential energy surfaces accurately. The combination of our symmetric neural networks and the function-derivative fitting effectively produces PES fits using fewer numbers of training data points. For H(2)O, only 282 configurations are employed as the training set; the testing root-mean-squared and mean-absolute energy errors are respectively reported as 0.0103 eV (0.236 kcal/mol) and 0.0078 eV (0.179 kcal/mol). In the ClOOCl case, 1693 configurations are required to construct the training set; the root-mean-squared and mean-absolute energy errors for the ClOOCl testing set are 0.0409 eV (0.943 kcal/mol) and 0.0269 eV (0.620 kcal/mol), respectively. Overall, we find good agreements between ab initio and NN prediction in term of energy and gradient errors, and conclude that the new feed-forward neural-network models advantageously describe the molecules with excellent accuracy.

  13. Measuring evapotranspiration: comparison of in situ micrometeorological methods including eddy covariance, scintillometer, Bowen ratio, and surface renewal method

    Science.gov (United States)

    Poznikova, G.; Fischer, M.; Orsag, M.; Trnka, M.

    2016-12-01

    Quantifying evapotranspiration (ET) is a challenging task as different methods can induce large discrepancies. Comparisons of various techniques are not rare, however it is demanding to maintain several in situ measurements for longer time. In our study, we aimed to compare four micrometeorological methods measuring ET at relatively large homogeneous area. The study took place on a winter wheat field in Polkovice, the Czech Republic (49°23'42.8"N 17°14'47.3"E) from Jul 1st 2015 until Sep 15th 2015. In the centre of 26-ha experimental field we deployed the eddy covariance (EC) system, the Bowen ratio energy balance (BREB) system, thermocouples for surface renewal technique, and the surface layer scintillometer with 106 m path length. Additionally, we installed the large aperture scintillometer with 617 m path length across the field. Our results showed good agreement of compared methods during the wetter periods of the measurements with slight overestimation of the scintillometry. The BREB method agreed the best with EC. Both scintillometers gave very consistent results throughout the whole measurement period. The EC tended to underestimate other methods. One of potential reasons is energy balance disclosure which reached 27.4 % for the measured period. The surface renewal method showed good potential however, need to be further tested in our conditions. Our experimental locality is one of several we are running as a part of ground based measurement network for ET estimation. Gained results helped us to enhance and optimise our network to ensure effective and reliable data acquisition for future validation of airborne images (satellite based drought monitoring).

  14. Methods for generation of reporter phages and immobilization of active bacteriophages on a polymer surface

    Science.gov (United States)

    Applegate, Bruce Michael (Inventor); Perry, Lynda Louise (Inventor); Morgan, Mark Thomas (Inventor); Kothapalli, Aparna (Inventor)

    2012-01-01

    Novel reporter bacteriophages are provided. Provided are compositions and methods that allow bacteriophages that are used for specific detection or killing of E. coli 0157:H7 to be propagated in nonpathogenic E. coli, thereby eliminating the safety and security risks of propagation in E. coli 0157:H7. Provided are compositions and methods for attaching active bacteriophages to the surface of a polymer in order to kill target bacteria with which the phage comes into contact. Provided are modified bacteriophages immobilized to a surface, which capture E. coli 0157:H7 and cause the captured cells to emit light or fluorescence, allowing detection of the bacteria in a sample.

  15. Surface Modification of Ceramic Membranes with Thin-film Deposition Methods for Wastewater Treatment

    KAUST Repository

    Jahangir, Daniyal

    2017-12-01

    Membrane fouling, which is caused by deposition/adsorption of foulants on the surface or within membrane pores, still remains a bottleneck that hampers the widespread application of membrane bioreactor (MBR) technology for wastewater treatment. Recently membrane surface modification has proved to be a useful method in water/wastewater treatment to improve the surface hydrophilicity of membranes to obtain higher water fluxes and to reduce fouling. In this study, membrane modification was investigated by depositing a thin film of same thickness of TiO2 on the surface of an ultrafiltration alumina membrane. Various thin-film deposition (TFD) methods were employed, i.e. electron-beam evaporation, sputter and atomic layer deposition (ALD), and a comparative study of the methods was conducted to assess fouling inhibition performance in a lab-scale anaerobic MBR (AnMBR) fed with synthetic municipal wastewater. Thorough surface characterization of all modified membranes was carried out along with clean water permeability (CWP) tests and fouling behavior by bovine serum albumin (BSA) adsorption tests. The study showed better fouling inhibition performance of all modified membranes; however the effect varied due to different surface characteristics obtained by different deposition methods. As a result, ALD-modified membrane showed a superior status in terms of surface characteristics and fouling inhibition performance in AnMBR filtration tests. Hence ALD was determined to be the best TFD method for alumina membrane surface modification for this study. ALD-modified membranes were further characterized to determine an optimum thickness of TiO2-film by applying different ALD cycles. ALD treatment significantly improved the surface hydrophilicity of the unmodified membrane. Also ALD-TiO2 modification was observed to reduce the surface roughness of original alumina membrane, which in turn enhanced the anti-fouling properties of modified membranes. Finally, a same thickness of ALD

  16. DigiWarp: a method for deformable mouse atlas warping to surface topographic data

    International Nuclear Information System (INIS)

    Joshi, Anand A; Shattuck, David W; Toga, Arthur W; Chaudhari, Abhijit J; Li Changqing; Cherry, Simon R; Dutta, Joyita; Leahy, Richard M

    2010-01-01

    For pre-clinical bioluminescence or fluorescence optical tomography, the animal's surface topography and internal anatomy need to be estimated for improving the quantitative accuracy of reconstructed images. The animal's surface profile can be measured by all-optical systems, but estimation of the internal anatomy using optical techniques is non-trivial. A 3D anatomical mouse atlas may be warped to the estimated surface. However, fitting an atlas to surface topography data is challenging because of variations in the posture and morphology of imaged mice. In addition, acquisition of partial data (for example, from limited views or with limited sampling) can make the warping problem ill-conditioned. Here, we present a method for fitting a deformable mouse atlas to surface topographic range data acquired by an optical system. As an initialization procedure, we match the posture of the atlas to the posture of the mouse being imaged using landmark constraints. The asymmetric L 2 pseudo-distance between the atlas surface and the mouse surface is then minimized in order to register two data sets. A Laplacian prior is used to ensure smoothness of the surface warping field. Once the atlas surface is normalized to match the range data, the internal anatomy is transformed using elastic energy minimization. We present results from performance evaluation studies of our method where we have measured the volumetric overlap between the internal organs delineated directly from MRI or CT and those estimated by our proposed warping scheme. Computed Dice coefficients indicate excellent overlap in the brain and the heart, with fair agreement in the kidneys and the bladder.

  17. Interim report on the activity hold-up and ease of decontamination of permanent coatings and surface treatments incorporated in a glove box floor

    International Nuclear Information System (INIS)

    Dalton, J.T.; Eccles, E.W.; Sutcliffe, P.W.; Turner, A.D.; Dawson, R.K.

    1987-12-01

    A commercial GRP glove box has been equipped with 1 square foot tiles of alternative flooring materials. These comprise highly polished GRP, PEEK, electropolished stainless steel, cold-rolled stainless steel foil, bright nickel electroplate on stainless steel and hard chrome electroplate on stainless steel. The natural GRP finish was used as a reference surface. Standard PuO 2 handling and floor abrasion operations have been carried out on a regular basis. Subsequently, the floor tiles have been decontaminated by swabbing with Arklone soaked tissues and a mass balance has determined the fraction of PuO 2 unaccounted to be about 1%. Hard, smooth surfaces are promising to give the best performance in minimising activity retention under these abrasive conditions to ∼ 100 μg cm -2 . Glove box aerosol concentrations have also been monitored as a function of time after the completion of handling operations by air sampling and by gravity settling. After an initial rapid decrease over ∼ 2 hours, a steady state is reached corresponding to ∼ 1 ng/l of PuO 2 . (author)

  18. Interim report on the activity hold-up, and ease of decontamination of permanent coatings and surface treatments incorporated in a glove box floor

    International Nuclear Information System (INIS)

    Dalton, J.T.; Eccles, E.W.; Sutcliffe, P.W.; Turner, A.D.; Dawson, R.K.

    1987-11-01

    A commercial glass reinforced plastic (GRP) glove box has been equipped with 1 square foot tiles of alternative flooring materials. These comprise highly polished GRP, poly-ether-ether-ketone (PEEK), electropolished stainless steel, cold-rolled stainless steel foil, bright nickel electroplate on stainless steel and hard chrome electroplate on stainless steel. The natural GRP finish was used as a reference surface. Standard PuO 2 handling and floor abrasion operations have been carried out on a regular basis. Subsequently, the floor tiles have been decontaminated by swabbing with Arklone soaked tissues and a mass balance has determined the fraction of PuO 2 unaccounted to be about 1%. Hard, smooth surfaces are promising to give the best performance in minimizing activity retention under these abrasive conditions to ∼ 100 μg cm -2 . Glove box aerosol concentrations have also been monitored as a function of time after the completion of handling operations by air sampling and by gravity settling. After an initial rapid decrease over ∼ 2 hours, a steady state is reached corresponding to ∼ 1 ng/l of PuO 2 . (author)

  19. Analysis of the trajectory surface hopping method from the Markov state model perspective

    International Nuclear Information System (INIS)

    Akimov, Alexey V.; Wang, Linjun; Prezhdo, Oleg V.; Trivedi, Dhara

    2015-01-01

    We analyze the applicability of the seminal fewest switches surface hopping (FSSH) method of Tully to modeling quantum transitions between electronic states that are not coupled directly, in the processes such as Auger recombination. We address the known deficiency of the method to describe such transitions by introducing an alternative definition for the surface hopping probabilities, as derived from the Markov state model perspective. We show that the resulting transition probabilities simplify to the quantum state populations derived from the time-dependent Schrödinger equation, reducing to the rapidly switching surface hopping approach of Tully and Preston. The resulting surface hopping scheme is simple and appeals to the fundamentals of quantum mechanics. The computational approach is similar to the FSSH method of Tully, yet it leads to a notably different performance. We demonstrate that the method is particularly accurate when applied to superexchange modeling. We further show improved accuracy of the method, when applied to one of the standard test problems. Finally, we adapt the derived scheme to atomistic simulation, combine it with the time-domain density functional theory, and show that it provides the Auger energy transfer timescales which are in good agreement with experiment, significantly improving upon other considered techniques. (author)

  20. Investigation on multi-objective performance optimization algorithm application of fan based on response surface method and entropy method

    Science.gov (United States)

    Zhang, Li; Wu, Kexin; Liu, Yang

    2017-12-01

    A multi-objective performance optimization method is proposed, and the problem that single structural parameters of small fan balance the optimization between the static characteristics and the aerodynamic noise is solved. In this method, three structural parameters are selected as the optimization variables. Besides, the static pressure efficiency and the aerodynamic noise of the fan are regarded as the multi-objective performance. Furthermore, the response surface method and the entropy method are used to establish the optimization function between the optimization variables and the multi-objective performances. Finally, the optimized model is found when the optimization function reaches its maximum value. Experimental data shows that the optimized model not only enhances the static characteristics of the fan but also obviously reduces the noise. The results of the study will provide some reference for the optimization of multi-objective performance of other types of rotating machinery.

  1. Comprehensive assessment of parameterization methods for estimating clear-sky surface downward longwave radiation

    Science.gov (United States)

    Guo, Yamin; Cheng, Jie; Liang, Shunlin

    2018-02-01

    Surface downward longwave radiation (SDLR) is a key variable for calculating the earth's surface radiation budget. In this study, we evaluated seven widely used clear-sky parameterization methods using ground measurements collected from 71 globally distributed fluxnet sites. The Bayesian model averaging (BMA) method was also introduced to obtain a multi-model ensemble estimate. As a whole, the parameterization method of Carmona et al. (2014) performs the best, with an average BIAS, RMSE, and R 2 of - 0.11 W/m2, 20.35 W/m2, and 0.92, respectively, followed by the parameterization methods of Idso (1981), Prata (Q J R Meteorol Soc 122:1127-1151, 1996), Brunt and Sc (Q J R Meteorol Soc 58:389-420, 1932), and Brutsaert (Water Resour Res 11:742-744, 1975). The accuracy of the BMA is close to that of the parameterization method of Carmona et al. (2014) and comparable to that of the parameterization method of Idso (1981). The advantage of the BMA is that it achieves balanced results compared to the integrated single parameterization methods. To fully assess the performance of the parameterization methods, the effects of climate type, land cover, and surface elevation were also investigated. The five parameterization methods and BMA all failed over land with the tropical climate type, with high water vapor, and had poor results over forest, wetland, and ice. These methods achieved better results over desert, bare land, cropland, and grass and had acceptable accuracies for sites at different elevations, except for the parameterization method of Carmona et al. (2014) over high elevation sites. Thus, a method that can be successfully applied everywhere does not exist.

  2. A stabilized cut finite element method for the Darcy problem on surfaces

    Science.gov (United States)

    Hansbo, Peter; G. Larson, Mats; Massing, André

    2017-11-01

    We develop a cut finite element method for the Darcy problem on surfaces. The cut finite element method is based on embedding the surface in a three dimensional finite element mesh and using finite element spaces defined on the three dimensional mesh as trial and test functions. Since we consider a partial differential equation on a surface, the resulting discrete weak problem might be severely ill conditioned. We propose a full gradient and a normal gradient based stabilization computed on the background mesh to render the proposed formulation stable and well conditioned irrespective of the surface positioning within the mesh. Our formulation extends and simplifies the Masud-Hughes stabilized primal mixed formulation of the Darcy surface problem proposed in [28] on fitted triangulated surfaces. The tangential condition on the velocity and the pressure gradient is enforced only weakly, avoiding the need for any tangential projection. The presented numerical analysis accounts for different polynomial orders for the velocity, pressure, and geometry approximation which are corroborated by numerical experiments. In particular, we demonstrate both theoretically and through numerical results that the normal gradient stabilized variant results in a high order scheme.

  3. Method of surface error visualization using laser 3D projection technology

    Science.gov (United States)

    Guo, Lili; Li, Lijuan; Lin, Xuezhu

    2017-10-01

    In the process of manufacturing large components, such as aerospace, automobile and shipping industry, some important mold or stamped metal plate requires precise forming on the surface, which usually needs to be verified, if necessary, the surface needs to be corrected and reprocessed. In order to make the correction of the machined surface more convenient, this paper proposes a method based on Laser 3D projection system, this method uses the contour form of terrain contour, directly showing the deviation between the actually measured data and the theoretical mathematical model (CAD) on the measured surface. First, measure the machined surface to get the point cloud data and the formation of triangular mesh; secondly, through coordinate transformation, unify the point cloud data to the theoretical model and calculate the three-dimensional deviation, according to the sign (positive or negative) and size of the deviation, use the color deviation band to denote the deviation of three-dimensional; then, use three-dimensional contour lines to draw and represent every coordinates deviation band, creating the projection files; finally, import the projection files into the laser projector, and make the contour line projected to the processed file with 1:1 in the form of a laser beam, compare the Full-color 3D deviation map with the projection graph, then, locate and make quantitative correction to meet the processing precision requirements. It can display the trend of the machined surface deviation clearly.

  4. Methods of preparing internal combustion engine cylinder bore surfaces for frictional improvement

    Directory of Open Access Journals (Sweden)

    Chung Hwa Kong

    2017-01-01

    Full Text Available Frictional losses piston to cylinder bore contact is a major sources of mechanical losses in an internal combustion engine (ICE. Traditional plateau honing produces a relatively rough cylinder bore surface with many valleys for oil retention and plateau surfaces that are usually has micro roughness's that causes mechanical friction to act as a bearing surface. A smooth polished dimpled surface is more ideal to achieve low friction and wear in an ICE. Alternative methods to create a smooth dimpled surface on a hypereutectic aluminum ADC12 substrate for frictional improvements are evaluated in this study using an oscillating wear tester (OWT. The methods include casting in the dimples in the aluminum matrix, sandblasting as well as embossing the pits. The texture samples are evaluated by examining the surface properties, measuring frictional coefficient as well as wear characteristics. It was found that the samples embossed with #320 grit sandpaper and sandblasted with #240 sieve sand samples had a reduced coefficient of friction (μ of 23% at low sliding speeds before hydrodynamic lubrication mode and 6.9% in the fully hydrodynamic lubrication region.

  5. Comparison of optical design methods of freeform surfaces for imaging applications

    Science.gov (United States)

    Agócs, Tibor

    2015-09-01

    Optical systems based on freeform optical components offer many advantages over conventional systems in imaging applications, e.g. superior image quality, compact and lightweight designs. There are a few well established manufacturing method that can be used for the generation of freeform surfaces with low surface form error and low surface roughness, in the case of freeform mirrors e.g. diamond turning, nickel plating and post-polishing. Metrology is evolving rapidly, although developments are still needed in order to verify the manufactured surface with the necessary accuracy. Optical design methods of freeform surfaces are also lagging behind, many algorithms address non-imaging applications, but in the field of imaging (image-forming) only a few exists and works with various limitations. We compare the available techniques in freeform optical design for imaging and explore the advantages, disadvantages and boundary conditions of the different methods. We also intend to identify the most useful concepts and investigate how they can be embedded into commercially available optical design software.

  6. Distinguishing metal bioconcentration from particulate matter in moss tissue: Testing methods of removing particles attached to the moss surface

    Energy Technology Data Exchange (ETDEWEB)

    Spagnuolo, V.; Giordano, S. [Department of Biology, University of Naples Federico II, Via Cintia 4, I-80126 Napoli (Italy); Pérez-Llamazares, A.; Ares, A.; Carballeira, A.; Fernández, J.A. [Area de Ecología, Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Aboal, J.R., E-mail: jesusramon.aboal@usc.es [Area de Ecología, Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2013-10-01

    Accurate differentiation of the proportion of bioconcentrated metals (i.e. incorporated into cells) and the proportion that is not bioconcentrated (i.e. adsorbed at the surface) would lead to a better understanding of the uptake processes and would represent an advance in the use of mosses as biomonitors. Traditionally the methods used to remove contaminants that are not bioconcentrated were to wash the plant material with water or to apply the sequential elution technique, but nowadays both options are considered inaccurate for these purposes. The remaining possibilities are to clean the moss samples with a nitrogen jet or by power ultrasound. Samples of terrestrial moss Pseudoscleropodium purum (Hewd.) Fleisch. were collected from five sampling stations. Different nitrogen jet cleaning procedures and ultrasound cleaning procedures were applied to the mosses. To determine whether any of the treatments altered the membrane integrity of the moss samples, the concentrations of K were determined. The shoots were observed under a scanning electron microscope, and the size and number of particles were determined. Nitrogen jet cleaning was determined to be unacceptable because it damaged the phyllids and/or altered the membrane permeability and did not eliminate the particles from the moss surface. Moreover, ultrasound cleaning treatment should also discarded because of the loss of extracellular metals that are transferred to the water in which the moss is cleaned. - Highlights: • The cleaning of surface particles on mosses is an unresolved issue • The use of a nitrogen jet as cleaning procedure was ruled out • The use of ultrasound treatments as cleaning procedure was also discarded • Currently it is not possible to quantify the bioconcentrated metal fraction in mosses.

  7. Distinguishing metal bioconcentration from particulate matter in moss tissue: Testing methods of removing particles attached to the moss surface

    International Nuclear Information System (INIS)

    Spagnuolo, V.; Giordano, S.; Pérez-Llamazares, A.; Ares, A.; Carballeira, A.; Fernández, J.A.; Aboal, J.R.

    2013-01-01

    Accurate differentiation of the proportion of bioconcentrated metals (i.e. incorporated into cells) and the proportion that is not bioconcentrated (i.e. adsorbed at the surface) would lead to a better understanding of the uptake processes and would represent an advance in the use of mosses as biomonitors. Traditionally the methods used to remove contaminants that are not bioconcentrated were to wash the plant material with water or to apply the sequential elution technique, but nowadays both options are considered inaccurate for these purposes. The remaining possibilities are to clean the moss samples with a nitrogen jet or by power ultrasound. Samples of terrestrial moss Pseudoscleropodium purum (Hewd.) Fleisch. were collected from five sampling stations. Different nitrogen jet cleaning procedures and ultrasound cleaning procedures were applied to the mosses. To determine whether any of the treatments altered the membrane integrity of the moss samples, the concentrations of K were determined. The shoots were observed under a scanning electron microscope, and the size and number of particles were determined. Nitrogen jet cleaning was determined to be unacceptable because it damaged the phyllids and/or altered the membrane permeability and did not eliminate the particles from the moss surface. Moreover, ultrasound cleaning treatment should also discarded because of the loss of extracellular metals that are transferred to the water in which the moss is cleaned. - Highlights: • The cleaning of surface particles on mosses is an unresolved issue • The use of a nitrogen jet as cleaning procedure was ruled out • The use of ultrasound treatments as cleaning procedure was also discarded • Currently it is not possible to quantify the bioconcentrated metal fraction in mosses

  8. Quantification of aquifer properties with surface nuclear magnetic resonance in the Platte River valley, central Nebraska, using a novel inversion method

    Science.gov (United States)

    Irons, Trevor P.; Hobza, Christopher M.; Steele, Gregory V.; Abraham, Jared D.; Cannia, James C.; Woodward, Duane D.

    2012-01-01

    Surface nuclear magnetic resonance, a noninvasive geophysical method, measures a signal directly related to the amount of water in the subsurface. This allows for low-cost quantitative estimates of hydraulic parameters. In practice, however, additional factors influence the signal, complicating interpretation. The U.S. Geological Survey, in cooperation with the Central Platte Natural Resources District, evaluated whether hydraulic parameters derived from surface nuclear magnetic resonance data could provide valuable input into groundwater models used for evaluating water-management practices. Two calibration sites in Dawson County, Nebraska, were chosen based on previous detailed hydrogeologic and geophysical investigations. At both sites, surface nuclear magnetic resonance data were collected, and derived parameters were compared with results from four constant-discharge aquifer tests previously conducted at those same sites. Additionally, borehole electromagnetic-induction flowmeter data were analyzed as a less-expensive surrogate for traditional aquifer tests. Building on recent work, a novel surface nuclear magnetic resonance modeling and inversion method was developed that incorporates electrical conductivity and effects due to magnetic-field inhomogeneities, both of which can have a substantial impact on the data. After comparing surface nuclear magnetic resonance inversions at the two calibration sites, the nuclear magnetic-resonance-derived parameters were compared with previously performed aquifer tests in the Central Platte Natural Resources District. This comparison served as a blind test for the developed method. The nuclear magnetic-resonance-derived aquifer parameters were in agreement with results of aquifer tests where the environmental noise allowed data collection and the aquifer test zones overlapped with the surface nuclear magnetic resonance testing. In some cases, the previously performed aquifer tests were not designed fully to characterize

  9. Experimental analysis on removal factor of smear method in measurement of surface contamination

    International Nuclear Information System (INIS)

    Sugiura, Nobuyuki; Taira, Junichi; Takenaka, Keisuke; Yamanaka, Kazuo; Sugai, Kenji; Kosako, Toshiso

    2007-01-01

    The smear test is one of the important ways to measure surface contamination. The loose contamination under the high background radiation, which is more significant in handling non-sealed radioisotopes, can be evaluated by this method. The removal factor is defined as the ratio of the activity removed from the surface by one smear to the whole activity of the removable surface contamination. The removal factor is greatly changed by the quality and condition of surface materials. In this study, the values of removal factor at several typical surface conditions were evaluated experimentally and the practical application of those values was considered. It is required the smear should be pressed by moderate pressure when wiping the surface. The pressure from 1.0 kg to 1.5 kg per filter paper was recommended. The removal factor showed lower value in wiping by the pressure below 1.0 kg. The value of 0.5 for the removal factor could be applied to the smooth surface of linoleum, concrete coated with paint or epoxy resin, stainless steel and glass with the statistical allowance. (author)

  10. Modelling and investigation of partial wetting surfaces for drop dynamics using lattice Boltzmann method

    Science.gov (United States)

    Pravinraj, T.; Patrikar, Rajendra

    2017-07-01

    Partial wetting surfaces and its influence on the droplet movement of micro and nano scale being contemplated for many useful applications. The dynamics of the droplet usually analyzed with a multiphase lattice Boltzmann method (LBM). In this paper, the influence of partial wetting surface on the dynamics of droplet is systematically analyzed for various cases. Splitting of droplets due to chemical gradient of the surface is studied and analyses of splitting time for various widths of the strips for different Weber numbers are computed. With the proposed model one can tune the splitting volume and time by carefully choosing a strip width and droplet position. The droplet spreading on chemically heterogeneous surfaces shows that the spreading can be controlled not only by parameters of Weber number but also by tuning strip width ratio. The transportation of the droplet from hydrophobic surface to hydrophilic surface due to chemical gradient is simulated and analyzed using our hybrid thermodynamic-image processing technique. The results prove that with the progress of time the surface free energy decreases with increase in spreading area. Finally, the transportation of a droplet on microstructure gradient is demonstrated. The model explains the temporal behaviour of droplet during the spreading, recoiling and translation along with tracking of contact angle hysteresis phenomenon.

  11. Surface Nano Structures Manufacture Using Batch Chemical Processing Methods for Tooling Applications

    DEFF Research Database (Denmark)

    Tosello, Guido; Calaon, Matteo; Gavillet, J.

    2011-01-01

    The patterning of large surface areas with nano structures by using chemical batch processes to avoid using highenergy intensive nano machining processes was investigated. The capability of different surface treatment methods of creating micro and nano structured adaptable mould inserts...... for subsequent polymer replication by injection moulding was analyzed. New tooling solutions to produce nano structured mould surfaces were investigated. Experiments based on three different chemical-based-batch techniques to establish surface nano (i.e. sub-μm) structures on large areas were performed. Three...... approaches were selected: (1) using Ø500 nm nano beads deposition for direct patterning of a 4” silicon wafer; (2) using Ø500 nm nano beads deposition as mask for 4” silicon wafer etching and subsequent nickel electroplating; (3) using the anodizing process to produce Ø500 nm structures on a 30x80 mm2...

  12. Method for atmospheric pressure reactive atom plasma processing for surface modification

    Science.gov (United States)

    Carr, Jeffrey W [Livermore, CA

    2009-09-22

    Reactive atom plasma processing can be used to shape, polish, planarize and clean the surfaces of difficult materials with minimal subsurface damage. The apparatus and methods use a plasma torch, such as a conventional ICP torch. The workpiece and plasma torch are moved with respect to each other, whether by translating and/or rotating the workpiece, the plasma, or both. The plasma discharge from the torch can be used to shape, planarize, polish, and/or clean the surface of the workpiece, as well as to thin the workpiece. The processing may cause minimal or no damage to the workpiece underneath the surface, and may involve removing material from the surface of the workpiece.

  13. Method of making self-cleaning skin-like prosthetic polymer surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, John T.; Ivanov, Ilia N.; Shibata, Jason

    2017-06-06

    An external covering and method of making an external covering for hiding the internal endoskeleton of a mechanical (e.g., prosthetic) device that exhibits skin-like qualities is provided. The external covering generally comprises an internal bulk layer in contact with the endoskeleton of the prosthetic device and an external skin layer disposed about the internal bulk layer. The external skin layer is comprised of a polymer composite with carbon nanotubes embedded therein. The outer surface of the skin layer has multiple cone-shaped projections that provide the external skin layer with superhydrophobicity. The carbon nanotubes are preferably vertically aligned between the inner surface and outer surface of the external skin layer in order to provide the skin layer with the ability to transmit heat. Superhydrophobic powders may optionally be used as part of the polymer composite or applied as a coating to the surface of the skin layer to enhance superhydrophobicity.

  14. Solving eigenvalue problems on curved surfaces using the Closest Point Method

    KAUST Repository

    Macdonald, Colin B.

    2011-06-01

    Eigenvalue problems are fundamental to mathematics and science. We present a simple algorithm for determining eigenvalues and eigenfunctions of the Laplace-Beltrami operator on rather general curved surfaces. Our algorithm, which is based on the Closest Point Method, relies on an embedding of the surface in a higher-dimensional space, where standard Cartesian finite difference and interpolation schemes can be easily applied. We show that there is a one-to-one correspondence between a problem defined in the embedding space and the original surface problem. For open surfaces, we present a simple way to impose Dirichlet and Neumann boundary conditions while maintaining second-order accuracy. Convergence studies and a series of examples demonstrate the effectiveness and generality of our approach. © 2011 Elsevier Inc.

  15. A novel method of freeform surface grinding with a soft wheel based on industrial robots

    Science.gov (United States)

    Sha, Sheng-chun; Guo, Xiao-ling

    2011-08-01

    In order to meet the growing demand for high-quality images, optical elements of freeform surface are more and more applied to imaging system. However the fabrication of freeform surface optical elements is much more difficult than that of traditional spherical ones. Recent research on freeform surface manufacture often deals with precision machine tools which have limitations on dimensions and are always expensive. Little has been researched on industrial robots. In this paper, a new method of freeform surface grinding based on industrial robots was found. This method could be applied to both whole surface grinding as well as partial surface grinding. The diameter of lenses to be ground would not be restricted to the machine tool's size. In this method a high-speed-rotating soft wheel was used. The relation between removing amount and grinding time which could be called removing function was established and measured. The machining precision was achieved by means of controlling the grinding time instead of the machine tool or industrial robot itself. There are two main factors affecting the removing function: i).rotating speed of the soft wheel; ii).pressure between the wheel and the work piece. In this paper, two groups of experiments have been conducted. One is the removing function tested at constant rotating speed while under different pressure. The other is that tested under a certain pressure with variable speed. Tables and curves which can show the effect of speed and pressure on the removing efficiency have been obtained. Cause for inaccuracy between experiment data and calculated result according to the theory and the non-linearity in the curves was analyzed. Through these analyses the removing function could be concluded under certain condition including rotating speed and pressure. Finally several experiments were performed to verify the appropriateness of the removing function. It could also be concluded that this method was more efficient in comparison

  16. Standard test method for calibration of surface/stress measuring devices

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1997-01-01

    Return to Contents page 1.1 This test method covers calibration or verification of calibration, or both, of surface-stress measuring devices used to measure stress in annealed and heat-strengthened or tempered glass using polariscopic or refractometry based principles. 1.2 This test method is nondestructive. 1.3 This test method uses transmitted light, and therefore, is applicable to light-transmitting glasses. 1.4 This test method is not applicable to chemically tempered glass. 1.5 Using the procedure described, surface stresses can be measured only on the “tin” side of float glass. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. The application of surface electrical and shallow geothermic methods in monitoring network design.

    Science.gov (United States)

    Gilkeson, R.H.; Cartwright, K.

    1983-01-01

    There are a variety of surface geophysical methods that are routinely used in geologic investigations. The three broad applications of these methods to evaluate the impact of waste disposal on shallow groundwater flow systems are: 1) evaluation of proposed waste disposal sites; 2) monitoring of site performance; and 3) investigation of contaminant migration at existing sites. Electrical and shallow geothermic are two surface geophysical methods that have application to waste disposal investigations. Of the electrical methods, electrical resistivity has the greatest application with a variety of techniques available. The distribution of temperature in shallow geologic materials (shallow geothermics) may define characteristics of shallow groundwater flow systems including zones of recharge and discharge and lithologic variation in the shallow geologic materials.-from Authors

  18. Proposal of a method for evaluating tsunami risk using response-surface methodology

    Science.gov (United States)

    Fukutani, Y.

    2017-12-01

    Information on probabilistic tsunami inundation hazards is needed to define and evaluate tsunami risk. Several methods for calculating these hazards have been proposed (e.g. Løvholt et al. (2012), Thio (2012), Fukutani et al. (2014), Goda et al. (2015)). However, these methods are inefficient, and their calculation cost is high, since they require multiple tsunami numerical simulations, therefore lacking versatility. In this study, we proposed a simpler method for tsunami risk evaluation using response-surface methodology. Kotani et al. (2016) proposed an evaluation method for the probabilistic distribution of tsunami wave-height using a response-surface methodology. We expanded their study and developed a probabilistic distribution of tsunami inundation depth. We set the depth (x1) and the slip (x2) of an earthquake fault as explanatory variables and tsunami inundation depth (y) as an object variable. Subsequently, tsunami risk could be evaluated by conducting a Monte Carlo simulation, assuming that the generation probability of an earthquake follows a Poisson distribution, the probability distribution of tsunami inundation depth follows the distribution derived from a response-surface, and the damage probability of a target follows a log normal distribution. We applied the proposed method to a wood building located on the coast of Tokyo Bay. We implemented a regression analysis based on the results of 25 tsunami numerical calculations and developed a response-surface, which was defined as y=ax1+bx2+c (a:0.2615, b:3.1763, c=-1.1802). We assumed proper probabilistic distribution for earthquake generation, inundation height, and vulnerability. Based on these probabilistic distributions, we conducted Monte Carlo simulations of 1,000,000 years. We clarified that the expected damage probability of the studied wood building is 22.5%, assuming that an earthquake occurs. The proposed method is therefore a useful and simple way to evaluate tsunami risk using a response-surface

  19. On-the-fly Numerical Surface Integration for Finite-Difference Poisson-Boltzmann Methods.

    Science.gov (United States)

    Cai, Qin; Ye, Xiang; Wang, Jun; Luo, Ray

    2011-11-01

    Most implicit solvation models require the definition of a molecular surface as the interface that separates the solute in atomic detail from the solvent approximated as a continuous medium. Commonly used surface definitions include the solvent accessible surface (SAS), the solvent excluded surface (SES), and the van der Waals surface. In this study, we present an efficient numerical algorithm to compute the SES and SAS areas to facilitate the applications of finite-difference Poisson-Boltzmann methods in biomolecular simulations. Different from previous numerical approaches, our algorithm is physics-inspired and intimately coupled to the finite-difference Poisson-Boltzmann methods to fully take advantage of its existing data structures. Our analysis shows that the algorithm can achieve very good agreement with the analytical method in the calculation of the SES and SAS areas. Specifically, in our comprehensive test of 1,555 molecules, the average unsigned relative error is 0.27% in the SES area calculations and 1.05% in the SAS area calculations at the grid spacing of 1/2Å. In addition, a systematic correction analysis can be used to improve the accuracy for the coarse-grid SES area calculations, with the average unsigned relative error in the SES areas reduced to 0.13%. These validation studies indicate that the proposed algorithm can be applied to biomolecules over a broad range of sizes and structures. Finally, the numerical algorithm can also be adapted to evaluate the surface integral of either a vector field or a scalar field defined on the molecular surface for additional solvation energetics and force calculations.

  20. Rewetting analysis of hot surfaces with internal heat source by the heat balance integral method

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, S.K.; Das, P.K.; Bhattacharyya, Souvik [IIT Kharagpur (India). Department of Mechanical Engineering

    2008-08-15

    A two region conduction-controlled rewetting model of hot vertical surfaces with internal heat generation and boundary heat flux subjected to constant but different heat transfer coefficient in both wet and dry region is solved by the Heat Balance Integral Method (HBIM). The HBIM yields the temperature field and quench front temperature as a function of various model parameters such as Peclet number, Biot number and internal heat source parameter of the hot surface. Further, the critical (dry out) internal heat source parameter is obtained by setting Peclet number equal to zero, which yields the minimum internal heat source parameter to prevent the hot surface from being rewetted. Using this method, it has been possible to derive a unified relationship for a two-dimensional slab and tube with both internal heat generation and boundary heat flux. The solutions are found to be in good agreement with other analytical results reported in literature. (orig.)

  1. A Versatile Star PEG Grafting Method for the Generation of Nonfouling and Nonthrombogenic Surfaces

    Directory of Open Access Journals (Sweden)

    Pradeep Kumar Thalla

    2013-01-01

    Full Text Available Polyethylene glycol (PEG grafting has a great potential to create nonfouling and nonthrombogenic surfaces, but present techniques lack versatility and stability. The present work aimed to develop a versatile PEG grafting method applicable to most biomaterial surfaces, by taking advantage of novel primary amine-rich plasma-polymerized coatings. Star-shaped PEG covalent binding was studied using static contact angle, X-ray photoelectron spectroscopy (XPS, and quartz crystal microbalance with dissipation monitoring (QCM-D. Fluorescence and QCM-D both confirmed strong reduction of protein adsorption when compared to plasma-polymerized coatings and pristine poly(ethyleneterephthalate (PET. Moreover, almost no platelet adhesion was observed after 15 min perfusion in whole blood. Altogether, our results suggest that primary amine-rich plasma-polymerized coatings offer a promising stable and versatile method for PEG grafting in order to create nonfouling and nonthrombogenic surfaces and micropatterns.

  2. Method for preparing microstructure arrays on the surface of thin film material

    KAUST Repository

    Wang, Peng

    2017-02-09

    Methods are provided for growing a thin film of a nanoscale material. Thin films of nanoscale materials are also provided. The films can be grown with microscale patterning. The method can include vacuum filtration of a solution containing the nanostructured material through a porous substrate. The porous substrate can have a pore size that is comparable to the size of the nanoscale material. By patterning the pores on the surface of the substrate, a film can be grown having the pattern on a surface of the thin film, including on the top surface opposite the substrate. The nanoscale material can be graphene, graphene oxide, reduced graphene oxide, molybdenum disulfide, hexagonal boron nitride, tungsten diselenide, molybdenum trioxide, or clays such as montmorillonite or lapnotie. The porous substrate can be a porous organic or inorganic membrane, a silicon stencil membrane, or similar membrane having pore sizes on the order of microns.

  3. Apparatus and method for atmospheric pressure reactive atom plasma processing for shaping of damage free surfaces

    Science.gov (United States)

    Carr,; Jeffrey, W [Livermore, CA

    2009-03-31

    Fabrication apparatus and methods are disclosed for shaping and finishing difficult materials with no subsurface damage. The apparatus and methods use an atmospheric pressure mixed gas plasma discharge as a sub-aperture polisher of, for example, fused silica and single crystal silicon, silicon carbide and other materials. In one example, workpiece material is removed at the atomic level through reaction with fluorine atoms. In this example, these reactive species are produced by a noble gas plasma from trace constituent fluorocarbons or other fluorine containing gases added to the host argon matrix. The products of the reaction are gas phase compounds that flow from the surface of the workpiece, exposing fresh material to the etchant without condensation and redeposition on the newly created surface. The discharge provides a stable and predictable distribution of reactive species permitting the generation of a predetermined surface by translating the plasma across the workpiece along a calculated path.

  4. Exploring the Leishmania Hydrophilic Acylated Surface Protein B (HASPB) Export Pathway by Live Cell Imaging Methods.

    Science.gov (United States)

    MacLean, Lorna; Price, Helen; O'Toole, Peter

    2016-01-01

    Leishmania major is a human-infective protozoan parasite transmitted by the bite of the female phlebotomine sand fly. The L. major hydrophilic acylated surface protein B (HASPB) is only expressed in infective parasite stages suggesting a role in parasite virulence. HASPB is a "nonclassically" secreted protein that lacks a conventional signal peptide, reaching the cell surface by an alternative route to the classical ER-Golgi pathway. Instead HASPB trafficking to and exposure on the parasite plasma membrane requires dual N-terminal acylation. Here, we use live cell imaging methods to further explore this pathway allowing visualization of key events in real time at the individual cell level. These methods include live cell imaging using fluorescent reporters to determine the subcellular localization of wild type and acylation site mutation HASPB18-GFP fusion proteins, fluorescence recovery after photobleaching (FRAP) to analyze the dynamics of HASPB in live cells, and live antibody staining to detect surface exposure of HASPB by confocal microscopy.

  5. A numerical method for calculation of electrostatic charge distribution induced on conducting surfaces

    OpenAIRE

    Saeed Hatamzadeh-Varmazyar; Zahra Masouri

    2014-01-01

    The focus of this article is on calculation of electrostatic charge distribution induced on conducting surfaces. For this purpose, the integral equation concept is used for mathematical modeling of the problem. A special set of exponential basis functions is introduced and defined to be used in formulation of a numerical method for solving the integral equation to obtain the charge distribution. The method is numerically evaluated via calculation of charge density for some structures by which...

  6. A Study on a Multi-Objective Optimization Method Based on Neuro-Response Surface Method (NRSM

    Directory of Open Access Journals (Sweden)

    Lee Jae-Chul

    2016-01-01

    Full Text Available The geometry of systems including the marine engineering problems needs to be optimized in the initial design stage. However, the performance analysis using commercial code is generally time-consuming. To solve this problem, many engineers perform the optimization process using the response surface method (RSM to predict the system performance, but RSM presents some prediction errors for nonlinear systems. The major objective of this research is to establish an optimal design framework. The framework is composed of three parts: definition of geometry, generation of response surface, and optimization process. To reduce the time for performance analysis and minimize the prediction errors, the response surface is generated using the artificial neural network (ANN which is considered as NRSM. The optimization process is done for the generated response surface by non-dominated sorting genetic algorithm-II (NSGA-II. Through case study of a derrick structure, we have confirmed the proposed framework applicability. In the future, we will try to apply the constructed framework to multi-objective optimization problems.

  7. Comparison of two split-window methods for retrieving land surface temperature from MODIS data

    Science.gov (United States)

    Zhao, Shaohua; Qin, Qiming; Yang, Yonghui; Xiong, Yujiu; Qiu, Guoyu

    2009-08-01

    Land surface temperature (LST) is a key parameter in environment and earth science study, especially for monitoring drought. The objective of this work is a comparison of two split-window methods: Mao method and Sobrino method, for retrieving LST using MODIS (Moderate-resolution Imaging Spectroradiometer) data in North China Plain. The results show that the max, min and mean errors of Mao method are 1.33K, 1.54K and 0.13K lower than the standard LST product respectively; while those of Sobrino method are 0.73K, 1.46K and 1.50K higher than the standard respectively. Validation of the two methods using LST product based on weather stations shows a good agreement between the standard and Sobrino method, with RMSE of 1.17K, whereas RMSE of Mao method is 1.85K. Finally, the study introduces the Sobmao method, which is based on Sobrino method but simplifies the estimation of atmospheric water vapour content using Mao method. The Sobmao method has almost the same accuracy with Sobrino method. With high accuracy and simplification of water vapour content estimation, the Sobmao method is recommendable in LST inversion for good application in Ningxia region, the northwest China, with mean error of 0.33K and the RMSE value of 0.91K.

  8. Comparison of Response Surface Construction Methods for Derivative Estimation Using Moving Least Squares, Kriging and Radial Basis Functions

    Science.gov (United States)

    Krishnamurthy, Thiagarajan

    2005-01-01

    Response construction methods using Moving Least Squares (MLS), Kriging and Radial Basis Functions (RBF) are compared with the Global Least Squares (GLS) method in three numerical examples for derivative generation capability. Also, a new Interpolating Moving Least Squares (IMLS) method adopted from the meshless method is presented. It is found that the response surface construction methods using the Kriging and RBF interpolation yields more accurate results compared with MLS and GLS methods. Several computational aspects of the response surface construction methods also discussed.

  9. Methods to Use Surface Infiltration Tests in Permeable Pavement Systems to Determine Maintenance Frequency

    Science.gov (United States)

    Currently, there is limited guidance on selecting test sites to measure surface infiltration rates in permeable pavement systems to determine maintenance frequency. The ASTM method (ASTM C1701) for measuring infiltration rate of in-place pervious concrete suggest to either (1) p...

  10. Instrumental research method of qualitative composition of landfill gas in the surface layer of landfills

    Science.gov (United States)

    Gilmanshin, I. R.; Kashapov, N. F.; Gilmanshina, S. I.; Galeeva, A. I.

    2017-09-01

    The article analyzes the practice of waste management in Russia. The system of target indicators of the efficient landfills functioning is formalized. The method of instrumental analysis of concentration and qualitative composition of landfill gas in the surface layer of the Samosyrovo landfill is presented.

  11. Application of Neural Networks to Wind tunnel Data Response Surface Methods

    Science.gov (United States)

    Lo, Ching F.; Zhao, J. L.; DeLoach, Richard

    2000-01-01

    The integration of nonlinear neural network methods with conventional linear regression techniques is demonstrated for representative wind tunnel force balance data modeling. This work was motivated by a desire to formulate precision intervals for response surfaces produced by neural networks. Applications are demonstrated for representative wind tunnel data acquired at NASA Langley Research Center and the Arnold Engineering Development Center in Tullahoma, TN.

  12. Generation of triangulated random surfaces by the Monte Carlo method in the grand canonical ensemble

    International Nuclear Information System (INIS)

    Zmushko, V.V.; Migdal, A.A.

    1987-01-01

    A model of triangulated random surfaces which is the discrete analog of the Polyakov string is considered. An algorithm is proposed which enables one to study the model by the Monte Carlo method in the grand canonical ensemble. Preliminary results on the determination of the critical index γ are presented

  13. Method to conjugate polysaccharide antigens to surfaces for the detection of antibodies

    DEFF Research Database (Denmark)

    Boas, Ulrik; Lind, Peter; Riber, Ulla

    2014-01-01

    microbeads modified with N-alkyl hydroxylamine and N-alkyl-O-methyl hydroxylamine surface groups by incubation of antigen and beads for 16 h at 40 oC without the need for coupling agents. The efficiency of the new method was evaluated by flow cytometry in model samples and serum samples containing antibodies...

  14. Integrating GPR and RIP Methods for Water Surface Detection of Geological Structures

    Directory of Open Access Journals (Sweden)

    Chieh-Hou Yang

    2006-01-01

    Full Text Available Geophysical surveying in water-covered and swampy areas is particularly challenging. This paper presents a new survey strategy for such surveying that integrates ground penetrating radar (GPR and resistivity image profiling (RIP methods at the water surface to investigate geologic structures beneath rivers, ponds, and swamps.

  15. A method for screening for the risk of chronic effects of surface water pollution.

    Science.gov (United States)

    Soldán, Přemysl; Badurová, Jana

    2013-01-01

    The article describes a method for screening for the risk of chronic surface water pollution which was developed at the T. G. Masaryk Water Research Institute. The approach, which is based on exotoxicological analyses, can be classed as a rapid method of assessment. The degree of risk of chronic effects surface water pollution is determined from an evaluation of two major parameters-toxicity and genotoxicity. As the method utilizes relative simple procedures for sample collection, pretreatment of the sample, chemical analyses, bioassays and results assessment, this approach is suitable for widespread practical use. Extensive utilization of this approach for assessing river basins in the Czech Republic has proved its suitability for a more sophisticated detection of the biological impact of surface water pollution. This is documented in the article where the method is used in a study of the Bílina River, and in the overview of the results of the risk assessment of chronic effects of surface water pollution in selected sections of three international river basins in the Czech Republic.

  16. Analysis of method of polarization surveying of water surface oil pollution

    Science.gov (United States)

    Zhukov, B. S.

    1979-01-01

    A method of polarization surveying of oil films on the water surface is analyzed. Model calculations of contrasted oil and water obtained with different orientations of the analyzer are discussed. The model depends on the spectral range, water transparency and oil film, and the selection of observational direction.

  17. The use of artificial intelligence methods for visual analysis of properties of surface layers

    Directory of Open Access Journals (Sweden)

    Tomasz Wójcicki

    2014-12-01

    Full Text Available [b]Abstract[/b]. The article presents a selected area of research on the possibility of automatic prediction of material properties based on the analysis of digital images. Original, holistic model of forecasting properties of surface layers based on a multi-step process that includes the selected methods of processing and analysis of images, inference with the use of a priori knowledge bases and multi-valued fuzzy logic, and simulation with the use of finite element methods is presented. Surface layers characteristics and core technologies of their production processes such as mechanical, thermal, thermo-mechanical, thermo-chemical, electrochemical, physical are discussed. Developed methods used in the model for the classification of images of the surface layers are shown. The objectives of the use of selected methods of processing and analysis of digital images, including techniques for improving the quality of images, segmentation, morphological transformation, pattern recognition and simulation of physical phenomena in the structures of materials are described.[b]Keywords[/b]: image analysis, surface layer, artificial intelligence, fuzzy logic

  18. Application of stereological methods to estimate post-mortem brain surface area using 3T MRI

    DEFF Research Database (Denmark)

    Furlong, Carolyn; García-Fiñana, Marta; Puddephat, Michael

    2013-01-01

    The Cavalieri and Vertical Sections methods of design based stereology were applied in combination with 3 tesla (i.e. 3T) Magnetic Resonance Imaging (MRI) to estimate cortical and subcortical volume, area of the pial surface, area of the grey-white matter boundary, and thickness of the cerebral c...

  19. Effect of processing method on surface and weathering characteristics of wood-flour/HDPE composites

    Science.gov (United States)

    Nicole M. Stark; Laurent M. Matuana; Craig M. Clemons

    2004-01-01

    Wood-plastic lumber is promoted as a low maintenance high-durability product. When exposed to accelerated weathering, however, wood-plastic composites may experience a color change and/or loss in mechanical properties. Different methods of manufacturing wood-plastic composites lead to different surface characteristics, which can influence weathering, In this study, 50...

  20. Influence of drying method on the surface energy of cellulose nanofibrils determined by inverse gas chromatography

    Science.gov (United States)

    Yucheng Peng; Douglas J. Gardner; Yousoo Han; Zhiyong Cai; Mandla A. Tshabalala

    2013-01-01

    Research and development of the renewable nanomaterial cellulose nanofibrils (CNFs) has received considerable attention. The effect of drying on the surface energy of CNFs was investigated. Samples of nanofibrillated cellulose (NFC) and cellulose nanocrystals (CNC) were each subjected to four separate drying methods: air-drying, freeze-drying, spray-drying, and...

  1. Ultrasound surface probe as a screening method for evaluating the patients with blunt abdominal trauma

    Directory of Open Access Journals (Sweden)

    Mohammad Nasr-Esfahani

    2014-01-01

    Full Text Available Background: Blunt abdominal trauma is one of the causes of mortality in emergency department. Free fluid in the abdomen due to intra-abdominal blunt trauma can be determined by the surface probe of ultrasound. Since the importance of this free fluid in hemodynamic stable patients with blunt trauma is associated with the unknown outcome for surgeons, this study was performed to evaluate the role of ultrasound surface probe as a screening method in evaluating the patients with blunt abdominal trauma. Materials and Methods: A descriptive-analytical study was done on 45 patients with blunt abdominal trauma and hemodynamic stability. The patients were evaluated twice during the three-hours, including repeated ultrasound surface probe and clinical examinations. Computerized tomography was also performed. The patients were divided based on the amount of the free fluid in the abdomen during the evaluations into two groups: Fixed or increased, and decreased free fluid. The results of the different evaluated methods were compared using the sensitivity and specificity. Results: From 17 patients with CT abnormalities, free fluid increased in 14 patients (82.4%. Free fluid was decreased in three patients who were discharged well from the surgery service without any complication. Surface probe in prognosis detection had a sensitivity of 82.4% and specificity of 92.9%. The percentage of false positive and negative ultrasound compared with CT scan was 7.1% and 17.6%. Also, positive and negative predictive value of the ultrasound with surface probe was 87.5% and 89.7% respectively. Conclusion: The use of the ultrasound with surface probe in the diagnosis of free fluid in blunt abdominal trauma in hemodynamic stable patients can be considered as a useful screening method.

  2. Four chemical methods of porcelain conditioning and their influence over bond strength and surface integrity

    Science.gov (United States)

    Stella, João Paulo Fragomeni; Oliveira, Andrea Becker; Nojima, Lincoln Issamu; Marquezan, Mariana

    2015-01-01

    OBJECTIVE: To assess four different chemical surface conditioning methods for ceramic material before bracket bonding, and their impact on shear bond strength and surface integrity at debonding. METHODS: Four experimental groups (n = 13) were set up according to the ceramic conditioning method: G1 = 37% phosphoric acid etching followed by silane application; G2 = 37% liquid phosphoric acid etching, no rinsing, followed by silane application; G3 = 10% hydrofluoric acid etching alone; and G4 = 10% hydrofluoric acid etching followed by silane application. After surface conditioning, metal brackets were bonded to porcelain by means of the Transbond XP system (3M Unitek). Samples were submitted to shear bond strength tests in a universal testing machine and the surfaces were later assessed with a microscope under 8 X magnification. ANOVA/Tukey tests were performed to establish the difference between groups (α= 5%). RESULTS: The highest shear bond strength values were found in groups G3 and G4 (22.01 ± 2.15 MPa and 22.83 ± 3.32 Mpa, respectively), followed by G1 (16.42 ± 3.61 MPa) and G2 (9.29 ± 1.95 MPa). As regards surface evaluation after bracket debonding, the use of liquid phosphoric acid followed by silane application (G2) produced the least damage to porcelain. When hydrofluoric acid and silane were applied, the risk of ceramic fracture increased. CONCLUSIONS: Acceptable levels of bond strength for clinical use were reached by all methods tested; however, liquid phosphoric acid etching followed by silane application (G2) resulted in the least damage to the ceramic surface. PMID:26352845

  3. Comparison of Surface Sampling Methods for Virus Recovery from Fomites ▿ †

    Science.gov (United States)

    Julian, Timothy R.; Tamayo, Francisco J.; Leckie, James O.; Boehm, Alexandria B.

    2011-01-01

    The role of fomites in infectious disease transmission relative to other exposure routes is difficult to discern due, in part, to the lack of information on the level and distribution of virus contamination on surfaces. Comparisons of studies intending to fill this gap are difficult because multiple different sampling methods are employed and authors rarely report their method's lower limit of detection. In the present study, we compare a subset of sampling methods identified from a literature review to demonstrate that sampling method significantly influences study outcomes. We then compare a subset of methods identified from the review to determine the most efficient methods for recovering virus from surfaces in a laboratory trial using MS2 bacteriophage as a model virus. Recoveries of infective MS2 and MS2 RNA are determined using both a plaque assay and quantitative reverse transcription-PCR, respectively. We conclude that the method that most effectively recovers virus from nonporous fomites uses polyester-tipped swabs prewetted in either one-quarter-strength Ringer's solution or saline solution. This method recovers a median fraction for infective MS2 of 0.40 and for MS2 RNA of 0.07. Use of the proposed method for virus recovery in future fomite sampling studies would provide opportunities to compare findings across multiple studies. PMID:21821742

  4. Construction of 4D high-definition cortical surface atlases of infants: Methods and applications.

    Science.gov (United States)

    Li, Gang; Wang, Li; Shi, Feng; Gilmore, John H; Lin, Weili; Shen, Dinggang

    2015-10-01

    In neuroimaging, cortical surface atlases play a fundamental role for spatial normalization, analysis, visualization, and comparison of results across individuals and different studies. However, existing cortical surface atlases created for adults are not suitable for infant brains during the first two postnatal years, which is the most dynamic period of postnatal structural and functional development of the highly-folded cerebral cortex. Therefore, spatiotemporal cortical surface atlases for infant brains are highly desired yet still lacking for accurate mapping of early dynamic brain development. To bridge this significant gap, leveraging our infant-dedicated computational pipeline for cortical surface-based analysis and the unique longitudinal infant MRI dataset acquired in our research center, in this paper, we construct the first spatiotemporal (4D) high-definition cortical surface atlases for the dynamic developing infant cortical structures at seven time points, including 1, 3, 6, 9, 12, 18, and 24 months of age, based on 202 serial MRI scans from 35 healthy infants. For this purpose, we develop a novel method to ensure the longitudinal consistency and unbiasedness to any specific subject and age in our 4D infant cortical surface atlases. Specifically, we first compute the within-subject mean cortical folding by unbiased groupwise registration of longitudinal cortical surfaces of each infant. Then we establish longitudinally-consistent and unbiased inter-subject cortical correspondences by groupwise registration of the geometric features of within-subject mean cortical folding across all infants. Our 4D surface atlases capture both longitudinally-consistent dynamic mean shape changes and the individual variability of cortical folding during early brain development. Experimental results on two independent infant MRI datasets show that using our 4D infant cortical surface atlases as templates leads to significantly improved accuracy for spatial normalization

  5. A Method for a Multi-Platform Approach to Generate Gridded Surface Evaporation

    Science.gov (United States)

    Badger, A.; Livneh, B.; Small, E. E.; Abolafia-Rosenzweig, R.

    2017-12-01

    Evapotranspiration is an integral component of the surface water balance. While there are many estimates of evapotranspiration, there are fewer estimates that partition evapotranspiration into evaporation and transpiration components. This study aims to generate a CONUS-scale, observationally-based soil evaporation dataset by using the time difference of surface soil moisture by Soil Moisture Active Passive (SMAP) satellite with adjustments for transpiration and a bottom flux out of the surface layer. In concert with SMAP, the Moderate-Resolution Imaging Spectroradiometer (MODIS) satellite, North American Land Data Assimilation Systems (NLDAS) and the Hydrus-1D model are used to fully analyze the surface water balance. A biome specific estimate of the total terrestrial ET is calculated through a variation of the Penman-Monteith equation with NLDAS forcing and NLDAS Noah Model output for meteorological variables. A root density restriction and SMAP-based soil moisture restriction are applied to obtain terrestrial transpiration estimates. By forcing Hydrus-1D with NLDAS meteorology and our terrestrial transpiration estimates, an estimate of the flux between the soil surface and root zone layers (qbot) will dictate the proportion of water that is available for soil evaporation. After constraining transpiration and the bottom flux from the surface layer, we estimate soil evaporation as the residual of the surface water balance. Application of this method at Fluxnet sites shows soil evaporation estimates of approximately 0­3 mm/day and less than ET estimates. Expanding this methodology to produce a gridded product for CONUS, and eventually a global-scale product, will enable a better understanding of water balance processes and contribute a dataset to validate land-surface model's surface flux processes.

  6. Coupled Finite Volume Methods and Extended Finite Element Methods for the Dynamic Crack Propagation Modelling with the Pressurized Crack Surfaces

    Directory of Open Access Journals (Sweden)

    Shouyan Jiang

    2017-01-01

    Full Text Available We model the fluid flow within the crack as one-dimensional flow and assume that the flow is laminar; the fluid is incompressible and accounts for the time-dependent rate of crack opening. Here, we discretise the flow equation by finite volume methods. The extended finite element methods are used for solving solid medium with crack under dynamic loads. Having constructed the approximation of dynamic extended finite element methods, the derivation of governing equation for dynamic extended finite element methods is presented. The implicit time algorithm is elaborated for the time descritisation of dominant equation. In addition, the interaction integral method is given for evaluating stress intensity factors. Then, the coupling model for modelling hydraulic fracture can be established by the extended finite element methods and the finite volume methods. We compare our present numerical results with our experimental results for verifying the proposed model. Finally, we investigate the water pressure distribution along crack surface and the effect of water pressure distribution on the fracture property.

  7. Methods of incorporating understanding of professional and ethical responsibility in the engineering curriculum and results from the Fundamentals of Engineering examination

    Science.gov (United States)

    Barry, Brock Edward

    This study evaluated the methods of incorporating professionalism and ethics in the engineering curriculum to determine the nature of the relationship between the curriculum model used and outcomes on a nationally administered, engineering-specific standardized examination. The study's population included engineering students enrolled at one of nine southeastern public universities between October 1996 and April 2005. The institutions are partners in the Multiple-Institution Database for Investigating Engineering Longitudinal Development (MIDFIELD) project. A mixed-methods (quantitative and qualitative) research program was designed and implemented. The qualitative aspects of the study focused on research questions related to the impetus and considerations given to curriculum changes made by the 23 engineering programs that participated in the study. The qualitative research questions were investigated using semi-structured interviews conducted with program representatives and evaluation of 49 ABET Self-Study accreditation documents. The curriculum model used by each of the participating programs were identified and defined for the period of the study and quantitatively compared to performance on the ethics section of the Fundamentals of Engineering (FE) Examination. The FE Examination is prepared and administered by the National Council for Engineering and Surveying (NCEES) and is the only nationally administered, engineering-specific, standardized assessment that measures performance on ABET-related criteria. A student-level dataset of subject scores was obtained for the FE Examination for all of the MIDFIELD programs. This study represents the first published attempt to utilize NCEES data for the purpose of rigorous educational research. Statistical techniques were used to evaluate the relationship between curriculum methods and examination performance. The findings indicate a statistical relationship, but a lack of structure between the amount of required

  8. Development of a new surface-exposure dating method based on luminescence

    Science.gov (United States)

    Sohbati, Reza; Murray, Andrew; Jain, Mayank; Egholm, David

    2013-04-01

    There are many examples of rock surfaces, rock art and stone structures whose ages are of great importance to the understanding of various phenomena in geology, climatology and archaeology. Optically stimulated luminescence (OSL) dating is a well-established chronological tool that has successfully determined the depositional age of a wide variety of fine-grained sediments, from several years to several hundred thousands of years. However, there is no routine OSL dating method applicable to larger clasts such as cobbles, boulders and other rock surfaces. We develop a technique of surface-exposure dating based upon the characteristic form of an OSL bleaching profile beneath a rock surface; this profile evolves as a function of depth and time. Our model takes into account the effect of both bleaching (energy release due to daylight exposure) and dose-rate (energy accumulation due to environmental radioactivity). As a field illustration of this new method, a fossil exposure age of ~700 years was determined for a buried rock sample at Canyonlands, Utah, USA, which allowed us, for the first time, to constrain the time frame for the creation of the Barrier Canyon Style rock art to 800-1500 years B.P. In another application of the model to quartzite cobbles from the Tapada do Montinho archaeological site (east-central Portugal), we were able to identify four events in the history of a single cobble; two exposure events of different time lengths and two burial events of 26 ka and 19 ka. In a more recent study, our preliminary results on high-elevation low-relief bedrock surfaces in western Scandinavia, suggest that surfaces at higher elevations may have been exposed for longer periods compared to those at lower elevations. This information could provide a direct quantitative constraint on the timing of the processes responsible for these surfaces in Sognefjord area, Norway. The new OSL surface-exposure dating method appears to have the potential to complement CN dating. By

  9. The high surface energy of NiO {110} facets incorporated into TiO{sub 2} hollow microspheres by etching Ti plate for enhanced photocatalytic and photoelectrochemical activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian; Cui, Hongzhi, E-mail: cuihongzhi1965@163.com; Song, Xiaojie; Wei, Na; Tian, Jian, E-mail: jiantian@sdust.edu.cn

    2017-02-28

    Highlights: • NiO/TiO{sub 2} hollow microspheres were fabricated by etching Ti plate. • The incorporated NiO nanoparticles exposed high surface energy {110} facets. • The p–n junction catalysts improved photoelectrochemical and photocatalytic activity. • Using this synthesis strategy, other mixed semiconducting metal oxide microspheres. - Abstract: We present a rational design for the controllable synthesis of NiO/TiO{sub 2} hollow microspheres (NTHMs) with Ti plate via a one-pot template-free synthesis strategy. Specifically, to enhance the formation of hollow microspheres, part of the titanium source is provided by the Ti plate. The hollow spherical NiO/TiO{sub 2} particles possess unique microstructural characteristics, namely, a higher specific surface area (∼65.82 m{sup 2} g{sup −1}), a larger mesoporous structure (∼7.79 nm), and hierarchical nanoarchitectures connected with mesopores within the shell (monodispersed size of ∼1 μm and shell thickness of ∼80 nm). In addition, as a cocatalyst for improved catalytic activity, the incorporated NiO nanoparticles with exposed high surface energy {110} facets displayed an outstanding performance. It has been proven that this facile nanostructure possesses remarkably high photoelectrochemical and photocatalytic activities. The main mechanism for enhancement of photocatalytic activity is attributed to the construction of p-n junctions with an inner electric field between TiO{sub 2} and NiO, which can dramatically enhance the separation efficiency of the photogenerated electron-hole pairs. This strategy could be applied to fabricate mixed metal oxide hollow microspheres toward the photoelectrochemical catalysis.

  10. Recent Trends in Surface Treatment Methods for Bonding Composite Cement to Zirconia: A Reveiw.

    Science.gov (United States)

    Khan, Aftab Ahmed; Al Kheraif, Abdul Aziz A; Jamaluddin, Syed; Elsharawy, Mohamad; Divakar, Darshan Devang

    To evaluate the in vitro studies conducted in the last six years on new zirconia materials to discover and explore current trends in bonding composite cement to zirconia substrate. An in-depth review of the in vitro studies performed between 2010 and 2016 was conducted, focusing on the current trends in surface conditioning methods for zirconia ceramic. PubMed was used for searching the literature. Resin composite bonding to zirconia, zirconia surface coating, and zirconia surface treatment method were the keywords used. Complete scientific articles were reviewed and evaluated for appropriateness. The literature survey showed a variety of surface treatment techniques comprising grit blasting (laboratory or chairside) with or without silica-coated alumina particles, the use of materials containing phosphate monomers, different silanes and primers, laser irradiation, Si vapor-phase deposition, and selective infiltration etching. The problem of composite cement bonding to zirconia has yet to be definitively solved. Nevertheless, the application of phosphate monomer on tribochemically silica-coated zirconia surfaces is currently the least complicated and most efficaceous means of bonding composite cement to zirconia. Selective infiltration etching seems to be a promising technique for establishing a durable bond between composite cement and zirconia, and should be studied further.

  11. Thermographic method for evaluation of thermal influence of exterior surface colour of buildings

    Science.gov (United States)

    Wu, Yanpeng; Li, Deying; Jin, Rendong; Liu, Li; Bai, Jiabin; Feng, Jianming

    2008-12-01

    Architecture colour is an important part in urban designing. It directly affects the expressing and the thermal effect of exterior surface of buildings. It has proved that four factors affect the sign visibility, graphics, colour, lighting condition and age of the observers, and colour is the main aspect. The best method is to prevent the exterior space heating up in the first place, by reflecting heat away room the exterior surface.The colour of paint to coat building's exterior wall can have a huge impact on energy efficiency. While the suitable colour is essential to increasing the energy efficiency of paint colour during the warm summer months, those products also help paint colour efficiency and reduce heat loss from buildings during winter months making the interior more comfortable all year long. The article is based on analyzing the importance of architecture color design and existing urban colour design. The effect of external surface colour on the thermal behaviour of a building has been studied experimentally by Infrared Thermographic method in University of Science and technology Beijing insummer.The experimental results showed that different colour has quietly different thermal effect on the exterior surface of buildings. The thermal effect of carmine and fawn has nearly the same values. The main factor which is color express, give some suggest ting about urban color design. The investigation reveals that the use of suitable surface colour can dramatically reduce maximum the temperatures of the exterior wall. Keywords: architectural colour, thermal, thermographic

  12. New method to estimate surface upwelling long-wave radiation from MODIS cloud-free data.

    Science.gov (United States)

    Wang, Chunlei; Tang, Bo-Hui; Huo, Xing; Li, Zhao-Liang

    2017-06-12

    As an important component in the surface radiation budget, surface upwelling longwave radiation (SULR) is an outcome of the land surface energy exchange and mainly represents the capability of thermal radiation from the surface of the Earth. Existing satellite-derived SULR products are too coarse to support high-resolution numerical models, and their accuracy needs to be improved. In this study, an equivalent temperature is introduced through which a "split-window" atmospheric correction algorithm is developed for MODIS data to estimate the instantaneous clear-sky SULR. It is a simple and feasible method that is particularly applicable to MODIS data to acquire relatively high precision SULR under clear skies from which qualified water vapor contents (WVC) and thermal channel brightness temperatures are available. The root mean square errors (RMSEs) are less than 13 W/m 2 for all WVC sub-ranges with the viewing zenith angle (VZA) less than 30°, or for all sub-ranges with the VZA less than 60° and the WVC less than 3.5 g/cm 2 . Also, applications and comparisons with the LST-emissivity method are made by using ground measurements which are collected from the network of surface radiation budget network data (SURFRAD) at the moment of MODIS overpass. Results show that the proposed model has high computational efficiency to estimate SULR from MODIS cloud-free data.

  13. Comparison of different polishing methods on the surface roughness of microhybrid, microfill, and nanofill composite resins.

    Science.gov (United States)

    Moda, Mariana D; Godas, André Gustavo de L; Fernandes, Juliana C; Suzuki, Thaís Y U; Guedes, Ana Paula A; Briso, André L F; Bedran-Russo, Ana Karina; Dos Santos, Paulo H

    2018-02-01

    The aim of the present study was to evaluate the effect of different polishing methods on the surface roughness of resin-based composites subjected to a thermocycling procedure. A total of 192 specimens were divided into 24 groups, according to composite materials (Filtek Z250, Point 4, Renamel Nanofill, Filtek Supreme Plus, Renamel Microfill, and Premise) and finishing and polishing systems (Sof-Lex Pop On, Super Snap, Flexidisc, and Flexidisc+Enamelize). The specimens were subjected to thermocycling (5000 cycles). Filtek Supreme Plus showed the lowest surface roughness values before thermocycling. After thermocycling, Filtek Supreme Plus continued to have the lowest surface roughness, with a statistically-significant difference for the other materials. After thermocycling, there was no statistically-significant difference among all the polishing techniques studied. The thermocycling was concluded as being able to change composite resins' surface roughness, whereas different finishing and polishing methods did not result in surface roughness changes after thermocycling. © 2017 John Wiley & Sons Australia, Ltd.

  14. Annual and Seasonal Glacier-Wide Surface Mass Balance Quantified from Changes in Glacier Surface State: A Review on Existing Methods Using Optical Satellite Imagery

    Directory of Open Access Journals (Sweden)

    Antoine Rabatel

    2017-05-01

    Full Text Available Glaciers are one of the terrestrial essential climate variables (ECVs as they respond very sensitively to climate change. A key driver of their response is the glacier surface mass balance that is typically derived from field measurements. It deserves to be quantified over long time scales to better understand the accumulation and ablation processes at the glacier surface and their relationships with inter-annual changes in meteorological conditions and long-term climate changes. Glaciers with in situ monitoring of surface mass balance are scarce at the global scale, and satellite remote sensing provides a powerful tool to increase the number of monitored glaciers. In this study, we present a review of three optical remote sensing methods developed to quantify seasonal and annual glacier surface mass balances. These methodologies rely on the multitemporal monitoring of the end-of-summer snow line for the equilibrium-line altitude (ELA method, the annual cycle of glacier surface albedo for the albedo method and the mapping of the regional snow cover at the seasonal scale for the snow-map method. Together with a presentation of each method, an application is illustrated. The ELA method shows promising results to quantify annual surface mass balance and to reconstruct multi-decadal time series. The other two methods currently need a calibration on the basis of existing in situ data; however, a generalization of these methods (without calibration could be achieved. The two latter methods show satisfying results at the annual and seasonal scales, particularly for the summer surface mass balance in the case of the albedo method and for the winter surface mass balance in the case of the snow-map method. The limits of each method (e.g., cloud coverage, debris-covered glaciers, monsoon-regime and cold glaciers, their complementarities and the future challenges (e.g., automating of the satellite images processing, generalization of the methods needing

  15. Dynamic modeling method of the bolted joint with uneven distribution of joint surface pressure

    Science.gov (United States)

    Li, Shichao; Gao, Hongli; Liu, Qi; Liu, Bokai

    2018-03-01

    The dynamic characteristics of the bolted joints have a significant influence on the dynamic characteristics of the machine tool. Therefore, establishing a reasonable bolted joint dynamics model is helpful to improve the accuracy of machine tool dynamics model. Because the pressure distribution on the joint surface is uneven under the concentrated force of bolts, a dynamic modeling method based on the uneven pressure distribution of the joint surface is presented in this paper to improve the dynamic modeling accuracy of the machine tool. The analytic formulas between the normal, tangential stiffness per unit area and the surface pressure on the joint surface can be deduced based on the Hertz contact theory, and the pressure distribution on the joint surface can be obtained by the finite element software. Futhermore, the normal and tangential stiffness distribution on the joint surface can be obtained by the analytic formula and the pressure distribution on the joint surface, and assigning it into the finite element model of the joint. Qualitatively compared the theoretical mode shapes and the experimental mode shapes, as well as quantitatively compared the theoretical modal frequencies and the experimental modal frequencies. The comparison results show that the relative error between the first four-order theoretical modal frequencies and the first four-order experimental modal frequencies is 0.2% to 4.2%. Besides, the first four-order theoretical mode shapes and the first four-order experimental mode shapes are similar and one-to-one correspondence. Therefore, the validity of the theoretical model is verified. The dynamic modeling method proposed in this paper can provide a theoretical basis for the accurate dynamic modeling of the bolted joint in machine tools.

  16. New methods to quantify NH3 volatilization from fertilized surface soil with urea

    Directory of Open Access Journals (Sweden)

    Ana Carolina Alves

    2011-02-01

    Full Text Available Gaseous N losses from soil are considerable, resulting mostly from ammonia volatilization linked to agricultural activities such as pasture fertilization. The use of simple and accessible measurement methods of such losses is fundamental in the evaluation of the N cycle in agricultural systems. The purpose of this study was to evaluate quantification methods of NH3 volatilization from fertilized surface soil with urea, with minimal influence on the volatilization processes. The greenhouse experiment was arranged in a completely randomized design with 13 treatments and five replications, with the following treatments: (1 Polyurethane foam (density 20 kg m-3 with phosphoric acid solution absorber (foam absorber, installed 1, 5, 10 and 20 cm above the soil surface; (2 Paper filter with sulfuric acid solution absorber (paper absorber, 1, 5, 10 and 20 cm above the soil surface; (3 Sulfuric acid solution absorber (1, 5 and 10 cm above the soil surface; (4 Semi-open static collector; (5 15N balance (control. The foam absorber placed 1 cm above the soil surface estimated the real daily rate of loss and accumulated loss of NH3N and proved efficient in capturing NH3 volatized from urea-treated soil. The estimates based on acid absorbers 1, 5 and 10 cm above the soil surface and paper absorbers 1 and 5 cm above the soil surface were only realistic for accumulated N-NH3 losses. Foam absorbers can be indicated to quantify accumulated and daily rates of NH3 volatilization losses similarly to an open static chamber, making calibration equations or correction factors unnecessary.

  17. Novel method for the measurement of liquid film thickness during fuel spray impingement on surfaces.

    Science.gov (United States)

    Henkel, S; Beyrau, F; Hardalupas, Y; Taylor, A M K P

    2016-02-08

    This paper describes the development and application of a novel optical technique for the measurement of liquid film thickness formed on surfaces during the impingement of automotive fuel sprays. The technique makes use of the change of the light scattering characteristics of a metal surface with known roughness, when liquid is deposited. Important advantages of the technique over previously established methods are the ability to measure the time-dependent spatial distribution of the liquid film without a need to add a fluorescent tracer to the liquid, while the measurement principle is not influenced by changes of the pressure and temperature of the liquid or the surrounding gas phase. Also, there is no need for non-fluorescing surrogate fuels. However, an in situ calibration of the dependence of signal intensity on liquid film thickness is required. The developed method can be applied to measure the time-dependent and two-dimensional distribution of the liquid fuel film thickness on the piston or the liner of gasoline direct injection (GDI) engines. The applicability of this technique was evaluated with impinging sprays of several linear alkanes and alcohols with different thermo-physical properties. The surface temperature of the impingement plate was controlled to simulate the range of piston surface temperatures inside a GDI engine. Two sets of liquid film thickness measurements were obtained. During the first set, the surface temperature of the plate was kept constant, while the spray of different fuels interacted with the surface. In the second set, the plate temperature was adjusted to match the boiling temperature of each fuel. In this way, the influence of the surface temperature on the liquid film created by the spray of different fuels and their evaporation characteristics could be demonstrated.

  18. The Finite-Surface Method for incompressible flow: a step beyond staggered grid

    Science.gov (United States)

    Hokpunna, Arpiruk; Misaka, Takashi; Obayashi, Shigeru

    2017-11-01

    We present a newly developed higher-order finite surface method for the incompressible Navier-Stokes equations (NSE). This method defines the velocities as a surface-averaged value on the surfaces of the pressure cells. Consequently, the mass conservation on the pressure cells becomes an exact equation. The only things left to approximate is the momentum equation and the pressure at the new time step. At certain conditions, the exact mass conservation enables the explicit n-th order accurate NSE solver to be used with the pressure treatment that is two or four order less accurate without loosing the apparent convergence rate. This feature was not possible with finite volume of finite difference methods. We use Fourier analysis with a model spectrum to determine the condition and found that the range covers standard boundary layer flows. The formal convergence and the performance of the proposed scheme is compared with a sixth-order finite volume method. Finally, the accuracy and performance of the method is evaluated in turbulent channel flows. This work is partially funded by a research colloaboration from IFS, Tohoku university and ASEAN+3 funding scheme from CMUIC, Chiang Mai University.

  19. Effective Wettability of Heterogenous Fracture Surfaces Using the Lattice-Boltzmann Method

    Science.gov (United States)

    E Santos, J.; Prodanovic, M.; Landry, C. J.

    2017-12-01

    Fracture walls in the subsurface are often structured by minerals of different composition (potentially further altered in contact with fluids during hydrocarbon extraction or CO2 sequestration), this yields in a heterogeneous wettability of the surface in contact with the fluids. The focus of our work is to study how surfaces presenting different mineralogy and roughness affect multiphase flow in fractures. Using the Shan-Chen model of the lattice-Boltzmann method (LBM) we define fluid interaction and surface attraction parameters to simulate a system of a wetting and a non-wetting fluid. In this work, we use synthetically created fractures presenting different arrangements of wetting and non-wetting patches, and with or without roughness; representative of different mineralogy, similar workflow can be applied to fractures extracted from X-ray microtomography images of fractures porous media. The results from the LBM simulations provide an insight on how the distribution of mineralogy and surface roughness are related with the observed macroscopic contact angle. We present a comparison between the published analytical models, and our results based on surface areas, spatial distribution and local fracture aperture. The understanding of the variables that affect the contact angle is useful for the comprehension of multiphase processes in naturally fractured reservoirs like primary oil production, enhanced oil recovery and CO2 sequestration. The macroscopic contact angle analytical equations for heterogeneous surfaces with variable roughness are no longer valid in highly heterogeneous systems; we quantify the difference thus offering an alternative to analytical models.

  20. The Detection of Vertical Cracks in Asphalt Using Seismic Surface Wave Methods

    International Nuclear Information System (INIS)

    Iodice, M; Muggleton, J; Rustighi, E

    2016-01-01

    Assessment of the location and of the extension of cracking in road surfaces is important for determining the potential level of deterioration in the road overall and the infrastructure buried beneath it. Damage in a pavement structure is usually initiated in the tarmac layers, making the Rayleigh wave ideally suited for the detection of shallow surface defects. This paper presents an investigation of two surface wave methods to detect and locate top-down cracks in asphalt layers. The aim of the study is to compare the results from the well- established Multichannel Analysis of Surface Waves (MASW) and the more recent Multiple Impact of Surface Waves (MISW) in the presence of a discontinuity and to suggest the best surface wave technique for evaluating the presence and the extension of vertical cracks in roads. The study is conducted through numerical simulations alongside experimental investigations and it considers the cases for which the cracking is internal and external to the deployment of sensors. MISW is found to enhance the visibility of the reflected waves in the frequency wavenumber ( f-k ) spectrum, helping with the detection of the discontinuity. In some cases, by looking at the f-k spectrum obtained with MISW it is possible to extract information regarding the location and the depth of the cracking. (paper)

  1. A Discovered Ducal Seal Does Not Belong to the Incorporation Charter for the City of Krakow Solving the Mystery Using Genetic Methods.

    Science.gov (United States)

    Lech, Tomasz

    2016-01-01

    The Incorporation Charter for the city of Krakow, the former capital of Poland, is one of the most valuable documents stored in the National Archives in Krakow. The document, which was written in 1257 on parchment, grants Krakow the Magdeburg rights and regulates its legal, statutory, economic and settlement-related aspects. The Charter was placed in the National Register of the Memory of the World UNESCO programme in 2014. A ducal seal, considered to be the lost seal detached from the Incorporation Charter, was found in the sphragistic collection after nearly 500 years. Unfortunately, it was uncertain whether the seal in question was indeed the missing part of the document. The aim of the study presented below was to solve this mystery. For this purpose, the parchment on which the Incorporation Charter was written was compared with the fragment of the parchment attached to the discovered seal. The study involved the analysis of selected mitochondrial DNA sequences and additional analysis at the level of nuclear DNA using microsatellite markers in the form of 11 STR (Short Tandem Repeat) loci, to identify the species and individual whose skin had been used to make the parchment. This analysis revealed that seal and parchment was from different individuals and thereby discovered that the seal was never a part of the Incorporation Charter. The study is further an example of informative DNA preservation in cultural heritage objects.

  2. Method for surface passivation and protection of cadmium zinc telluride crystals

    Science.gov (United States)

    Mescher, Mark J.; James, Ralph B.; Schlesinger, Tuviah E.; Hermon, Haim

    2000-01-01

    A method for reducing the leakage current in CZT crystals, particularly Cd.sub.1-x Zn.sub.x Te crystals (where x is greater than equal to zero and less than or equal to 0.5), and preferably Cd.sub.0.9 Zn.sub.0.1 Te crystals, thereby enhancing the ability of these crystal to spectrally resolve radiological emissions from a wide variety of radionuclides. Two processes are disclosed. The first method provides for depositing, via reactive sputtering, a silicon nitride hard-coat overlayer which provides significant reduction in surface leakage currents. The second method enhances the passivation by oxidizing the CZT surface with an oxygen plasma prior to silicon nitride deposition without breaking the vacuum state.

  3. A variable pressure method for characterizing nanoparticle surface charge using pore sensors.

    Science.gov (United States)

    Vogel, Robert; Anderson, Will; Eldridge, James; Glossop, Ben; Willmott, Geoff

    2012-04-03

    A novel method using resistive pulse sensors for electrokinetic surface charge measurements of nanoparticles is presented. This method involves recording the particle blockade rate while the pressure applied across a pore sensor is varied. This applied pressure acts in a direction which opposes transport due to the combination of electro-osmosis, electrophoresis, and inherent pressure. The blockade rate reaches a minimum when the velocity of nanoparticles in the vicinity of the pore approaches zero, and the forces on typical nanoparticles are in equilibrium. The pressure applied at this minimum rate can be used to calculate the zeta potential of the nanoparticles. The efficacy of this variable pressure method was demonstrated for a range of carboxylated 200 nm polystyrene nanoparticles with different surface charge densities. Results were of the same order as phase analysis light scattering (PALS) measurements. Unlike PALS results, the sequence of increasing zeta potential for different particle types agreed with conductometric titration.

  4. Oxygen termination of homoepitaxial diamond surface by ozone and chemical methods: An experimental and theoretical perspective

    Science.gov (United States)

    Navas, Javier; Araujo, Daniel; Piñero, José Carlos; Sánchez-Coronilla, Antonio; Blanco, Eduardo; Villar, Pilar; Alcántara, Rodrigo; Montserrat, Josep; Florentin, Matthieu; Eon, David; Pernot, Julien

    2018-03-01

    Phenomena related with the diamond surface of both power electronic and biosensor devices govern their global behaviour. In particular H- or O-terminations lead to wide variations in their characteristics. To study the origins of such aspects in greater depth, different methods to achieve oxygen terminated diamond were investigated following a multi-technique approach. DFT calculations were then performed to understand the different configurations between the C and O atoms. Three methods for O-terminating the diamond surface were performed: two physical methods with ozone at different pressures, and an acid chemical treatment. X-ray photoelectron spectroscopy, spectroscopic ellipsometry, HRTEM, and EELS were used to characterize the oxygenated surface. Periodic-DFT calculations were undertaken to understand the effect of the different ways in which the oxygen atoms are bonded to carbon atoms on the diamond surface. XPS results showed the presence of hydroxyl or ether groups, composed of simple Csbnd O bonds, and the acid treatment resulted in the highest amount of O on the diamond surface. In turn, ellipsometry showed that the different treatments led to the surface having different optical properties, such as a greater refraction index and extinction coefficient in the case of the sample subjected to acid treatment. TEM analysis showed that applying temperature treatment improved the distribution of the oxygen atoms at the interface and that this generates a thinner amount of oxygen at each position and higher interfacial coverage. Finally, DFT calculations showed both an increase in the number of preferential electron transport pathways when π bonds and ether groups appear in the system, and also the presence of states in the middle of the band gap when there are π bonds, Cdbnd C or Cdbnd O.

  5. Time varying eddy currents on a conducting surface in 3-D using a network mesh method

    International Nuclear Information System (INIS)

    Christensen, U.R.

    1979-04-01

    The method presented in this paper was developed for the purpose of analyzing the eddy currents in the TFTR vacuum vessel. The basic principle in this method lies in representing a conducting surface as a network comprised of a number of branches. Each branch has a resistance and a self-inductance as well as mutuals to all other branches. The resulting branch resistance and branch inductance matrices are transformed into mesh matrices by a conventional network procedure. By using these mesh matrices a set of simultaneous differential equations is then established. The eddy currents are then found by using a standard method for solving simultaneous differential equations

  6. Systems and methods for producing metal clusters; functionalized surfaces; and droplets including solvated metal ions

    Science.gov (United States)

    Cooks, Robert Graham; Li, Anyin; Luo, Qingjie

    2017-08-01

    The invention generally relates to systems and methods for producing metal clusters; functionalized surfaces; and droplets including solvated metal ions. In certain aspects, the invention provides methods that involve providing a metal and a solvent. The methods additionally involve applying voltage to the solvated metal to thereby produce solvent droplets including ions of the metal containing compound, and directing the solvent droplets including the metal ions to a target. In certain embodiments, once at the target, the metal ions can react directly or catalyze reactions.

  7. Application of Response Surface Methods To Determine Conditions for Optimal Genomic Prediction

    Science.gov (United States)

    Howard, Réka; Carriquiry, Alicia L.; Beavis, William D.

    2017-01-01

    An epistatic genetic architecture can have a significant impact on prediction accuracies of genomic prediction (GP) methods. Machine learning methods predict traits comprised of epistatic genetic architectures more accurately than statistical methods based on additive mixed linear models. The differences between these types of GP methods suggest a diagnostic for revealing genetic architectures underlying traits of interest. In addition to genetic architecture, the performance of GP methods may be influenced by the sample size of the training population, the number of QTL, and the proportion of phenotypic variability due to genotypic variability (heritability). Possible values for these factors and the number of combinations of the factor levels that influence the performance of GP methods can be large. Thus, efficient methods for identifying combinations of factor levels that produce most accurate GPs is needed. Herein, we employ response surface methods (RSMs) to find the experimental conditions that produce the most accurate GPs. We illustrate RSM with an example of simulated doubled haploid populations and identify the combination of factors that maximize the difference between prediction accuracies of best linear unbiased prediction (BLUP) and support vector machine (SVM) GP methods. The greatest impact on the response is due to the genetic architecture of the population, heritability of the trait, and the sample size. When epistasis is responsible for all of the genotypic variance and heritability is equal to one and the sample size of the training population is large, the advantage of using the SVM method vs. the BLUP method is greatest. However, except for values close to the maximum, most of the response surface shows little difference between the methods. We also determined that the conditions resulting in the greatest prediction accuracy for BLUP occurred when genetic architecture consists solely of additive effects, and heritability is equal to one. PMID

  8. Improved Method for Quantifying Nonvolatile Residues on Surfaces and in Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Benkovich, M.G.

    2004-03-30

    The objective of the project was to develop an improved method to quantify nonvolatile residues on surfaces and in liquids. The project accomplishments are summarized below: (1) ERA Systems, Inc., The MESERAN Company has designed, developed, built, evaluated, tested, and delivered MicroSolventEvaporator systems to KCP, Astro Pak, and Lockheed Martin, that automatically deposit and evaporate successive small quantities (5-10 microliters) of solvents onto clean reference surfaces. (2) ERA Systems, Inc., The MESERAN Company, and KCP have designed, procured, and evaluated stainless steel disks with specific machined grooves to be used as reference surfaces with the MicroSolventEvaporator and MESERAN Analyzers. (3) KCP evaluated various cleaning processes to easily clean the reference surfaces to acceptable levels. Even though some methods (or a combination of methods) may have worked better than others, an easy method that most companies could use to acceptably clean the disks was desired. Aqueous ultrasonic cleaning with Dirl Lum 603 (30 g per liter concentration) followed by flowing DI water and ultrasonic DI water rinses, nitrogen blow drying, and baking in a HEPA filtered oven at 220 F for 30 minutes proved to be a relatively simple method that most companies could use. (4) KCP developed calibrations of several contaminants on the chosen reference substrates so the MESERAN data could be converted into quantifiable amounts of contamination. (5) KCP performed a prove-in of the MicroSolventEvaporator in conjunction with the MESERAN Analyzer and compared the results to gravimetric data. The method worked and was able to provide data at low contamination levels that can not be reliably obtained gravimetrically. (6) Astro Pak and Lockheed Martin have done limited testing at their facilities. The MESERAN Company has agreed to let them keep the units for awhile so they can continue to perform tests to prove-in the process at their facilities even after the CRADA is

  9. Free surface simulation of a two-layer fluid by boundary element method

    Directory of Open Access Journals (Sweden)

    Weoncheol Koo

    2010-09-01

    Full Text Available A two-layer fluid with free surface is simulated in the time domain by a two-dimensional potential-based Numerical Wave Tank (NWT. The developed NWT is based on the boundary element method and a leap-frog time integration scheme. A whole domain scheme including interaction terms between two layers is applied to solve the boundary integral equation. The time histories of surface elevations on both fluid layers in the respective wave modes are verified with analytic results. The amplitude ratios of upper to lower elevation for various density ratios and water depths are also compared.

  10. Direct methods determination of the Si(111)-(6x6)Au surface structure

    DEFF Research Database (Denmark)

    Grozea, D.; Landree, E.; Marks, L.D.

    1998-01-01

    The atomic structure of the Au 6 x 6 on Si(111) phase has been determined using direct methods and surface X-ray diffraction data. This surface structure is very complicated, with 14 independent gold atoms, relaxations in 24 independent silicon sites and three partially occupied gold sites. In one...... the gold structures in the coverage range 0.8-1.5 monolayers as pseudo-glasses with strong short-range order but varying degrees of long-range order. (C) 1998 Elsevier Science B.V. All rights reserved....

  11. Band Structure and Fermi Surface of Cu2Sb by the LMTO Method

    DEFF Research Database (Denmark)

    Jan, J. P.; Skriver, Hans Lomholt

    1977-01-01

    The linear muffin-tin orbital (LMTO) method of bandstructure calculation has been applied to the simple tetragonal compound Cu2Sb. The d bands of Cu lie substantially below the Fermi level, and the Fermi surface is a recognizable distortion of the free-electron model. The Fermi surface has sheets......-orbit splitting, and of another closed sheet. Earlier de Haas-van Alphen results are explained semiquantitatively by the model, which also accounts for open orbits seen in high-field magnetoresistance experiments....

  12. On the inclusion of the diagonal Born-Oppenheimer correction in surface hopping methods

    Energy Technology Data Exchange (ETDEWEB)

    Gherib, Rami; Ryabinkin, Ilya G.; Izmaylov, Artur F. [Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4 (Canada); Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6 (Canada); Ye, Liyuan [Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4 (Canada)

    2016-04-21

    The diagonal Born-Oppenheimer correction (DBOC) stems from the diagonal second derivative coupling term in the adiabatic representation, and it can have an arbitrary large magnitude when a gap between neighbouring Born-Oppenheimer (BO) potential energy surfaces (PESs) is closing. Nevertheless, DBOC is typically neglected in mixed quantum-classical methods of simulating nonadiabatic dynamics (e.g., fewest-switch surface hopping (FSSH) method). A straightforward addition of DBOC to BO PESs in the FSSH method, FSSH+D, has been shown to lead to numerically much inferior results for models containing conical intersections. More sophisticated variation of the DBOC inclusion, phase-space surface-hopping (PSSH) was more successful than FSSH+D but on model problems without conical intersections. This work comprehensively assesses the role of DBOC in nonadiabatic dynamics of two electronic state problems and the performance of FSSH, FSSH+D, and PSSH methods in variety of one- and two-dimensional models. Our results show that the inclusion of DBOC can enhance the accuracy of surface hopping simulations when two conditions are simultaneously satisfied: (1) nuclei have kinetic energy lower than DBOC and (2) PESs are not strongly nonadiabatically coupled. The inclusion of DBOC is detrimental in situations where its energy scale becomes very high or even diverges, because in these regions PESs are also very strongly coupled. In this case, the true quantum formalism heavily relies on an interplay between diagonal and off-diagonal nonadiabatic couplings while surface hopping approaches treat diagonal terms as PESs and off-diagonal ones stochastically.

  13. Comparison of surface detection methods to evaluate cone beam computed tomography data for three dimensional metrology

    International Nuclear Information System (INIS)

    Heinzl, Ch.; Kastner, J.; Georgi, B.; Lettenbauer, H.

    2007-01-01

    X-ray computed tomography (CT) is a well established method for non-destructive testing. In recent years the application of CT for three dimensional measurements and variance comparison became more and more important, since CT can measure both outer and inner geometries within a rather short time. Because of the much higher measurement speed and thus lower costs especially cone beam CT is an important issue of research in the field of dimensional metrology. One of the biggest challenges for the application of CT for metrology is the accurate detection of the surface between material and air or the interface between two different materials. By using a test-body various algorithms and data evaluation methods are compared and discussed within this paper. The investigated methods are: 1. Common methods: Otsu global threshold and an empirically determined best iso-surface. 2. Pipeline model: The pipeline model uses common 3D image processing filters and consists of three major steps: a.) an edge preserving diffusion filter to reduce noise without blurring the edges of the specimen. b.) A watershed segmentation filter is applied to the gradient image of the dataset to extract a fully connected binary volume. c.) The object surface is constructed using elastic surface nets. 3. Calypso R : Evaluation of inspection features by introduction of additional geometry information. The geometrical value is directly derived from the volume data without extracting a surface model, supposing a predefined geometry of a feature. For this purpose the commercial software Calypso R was used. By defining a geometrical feature e.g. a diameter or a distance optimised algorithms evaluate the CT - volume data to get the geometrical feature without a transformation to surface data. Common methods usually lead to no satisfactory results. The achieved accuracy is rather low, if the material thickness in the sample changes. The pipeline model and CT- Calypso R lead to much better results. Using

  14. A New Method for Urban Storm Flood Inundation Simulation with Fine CD-TIN Surface

    Directory of Open Access Journals (Sweden)

    Zhifeng Li

    2014-05-01

    Full Text Available Urban storm inundation, which frequently has dramatic impacts on city safety and social life, is an emergent and difficult issue. Due to the complexity of urban surfaces and the variety of spatial modeling elements, the lack of detailed hydrological data and accurate urban surface models compromise the study and implementation of urban storm inundation simulations. This paper introduces a Constrained Delaunay Triangular Irregular Network (CD-TIN to model fine urban surfaces (based on detailed ground sampling data and subsequently employs a depression division method that refers to Fine Constrained Features (FCFs to construct computational urban water depressions. Storm-runoff yield is placed through mass conservation to calculate the volume of rainfall, runoff and drainage. The water confluences between neighboring depressions are provided when the water level exceeds the outlet of a certain depression. Numerical solutions achieved through a dichotomy are introduced to obtain the water level. Therefore, the continuous inundation process can be divided into different time intervals to obtain a series of inundation scenarios. The main campus of Beijing Normal University (BNU was used as a case study to simulate the “7.21” storm inundation event to validate the usability and suitability of the proposed methods. In comparing the simulation results with in-situ observations, the proposed method is accurate and effective, with significantly lower drainage data requirements being obtained. The proposed methods will also be useful for urban drainage design and city inundation emergency preparations.

  15. A novel surface mesh deformation method for handling wing-fuselage intersections

    Directory of Open Access Journals (Sweden)

    Mario Jaime Martin-Burgos

    2017-02-01

    Full Text Available This paper describes a method for mesh adaptation in the presence of intersections, such as wing-fuselage. Automatic optimization tools, using Computational Fluid Dynamics (CFD simulations, face the problem to adapt the computational grid upon deformations of the boundary surface. When mesh regeneration is not feasible, due to the high cost to build up the computational grid, mesh deformation techniques are considered a cheap approach to adapt the mesh to changes on the geometry. Mesh adaptation is a well-known subject in the literature; however, there is very little work which deals with moving intersections. Without a proper treatment of the intersections, the use of automatic optimization methods for aircraft design is limited to individual components. The proposed method takes advantage of the CAD description, which usually comes in the form of Non-Uniform Rational B-Splines (NURBS patches. This paper describes an algorithm to recalculate the intersection line between two parametric surfaces. Then, the surface mesh is adapted to the moving intersection in parametric coordinates. Finally, the deformation is propagated through the volumetric mesh. The proposed method is tested with the DLR F6 wing-body configuration.

  16. Numerical simulation of binary collisions using a modified surface tension model with particle method

    International Nuclear Information System (INIS)

    Sun Zhongguo; Xi Guang; Chen Xi

    2009-01-01

    The binary collision of liquid droplets is of both practical importance and fundamental value in computational fluid mechanics. We present a modified surface tension model within the moving particle semi-implicit (MPS) method, and carry out two-dimensional simulations to investigate the mechanisms of coalescence and separation of the droplets during binary collision. The modified surface tension model improves accuracy and convergence. A mechanism map is established for various possible deformation pathways encountered during binary collision, as the impact speed is varied; a new pathway is reported when the collision speed is critical. In addition, eccentric collisions are simulated and the effect of the rotation of coalesced particle is explored. The results qualitatively agree with experiments and the numerical protocol may find applications in studying free surface flows and interface deformation

  17. A Steel Ball Surface Quality Inspection Method Based on a Circumferential Eddy Current Array Sensor.

    Science.gov (United States)

    Zhang, Huayu; Xie, Fengqin; Cao, Maoyong; Zhong, Mingming

    2017-07-01

    To efficiently inspect surface defects on steel ball bearings, a new method based on a circumferential eddy current array (CECA) sensor was proposed here. The best probe configuration, in terms of the coil quality factor (Q-factor), magnetic field intensity, and induced eddy current density on the surface of a sample steel ball, was determined using 3-, 4-, 5-, and 6-coil probes, for analysis and comparison. The optimal lift-off from the measured steel ball, the number of probe coils, and the frequency of excitation current suitable for steel ball inspection were obtained. Using the resulting CECA sensor to inspect 46,126 steel balls showed a miss rate of ~0.02%. The sensor was inspected for surface defects as small as 0.05 mm in width and 0.1 mm in depth.

  18. A simple method for fabrication of filler-free stretchable polydimethylsiloxane surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Bacharouche, Jalal; Kunemann, Philippe; Fioux, Philippe; Vallat, Marie-France; Lalevée, Jacques [Institut de Sciences des Materiaux de Mulhouse, IS2M – C.N.R.S., LRC 7228 – UHA, 15, Rue Jean Starcky, 68057 Mulhouse Cedex (France); Hemmerlé, Joseph [Institut National de la Sante et de la Recherche Medicale, I.N.S.E.R.M. – Unite 595, 11, Rue Humann, 67085 Strasbourg Cedex (France); Roucoules, Vincent, E-mail: Vincent.Roucoules@uha.fr [Institut de Sciences des Materiaux de Mulhouse, IS2M – C.N.R.S., LRC 7228 – UHA, 15, Rue Jean Starcky, 68057 Mulhouse Cedex (France)

    2013-04-01

    We propose a simple method to elaborate a filler-free stretchable PDMS surface strong enough to resist to successive elongation/retraction cycles even at high degree of stretching. It consists in creating free radicals on a filler-containing PDMS surface by argon plasma exposure and reacting them with a filler-free PDMS resin during the crosslinking step. Changes of physical and chemical properties upon plasma modification are monitored by FTIR and XPS spectroscopies, contact angle measurements and atomic force microscopy. Electron spin resonance (ESR) is used to identify the nature of radicals involved in interfacial bonding. Although a brittle silica-like layer is created on the filler-containing PDMS surface after plasma treatment, an increase in the PDMS/PDMS interfacial strength is observed and a high interfacial resistance has been found under elongation/retraction (stretching/relaxation) cycles.

  19. A Steel Ball Surface Quality Inspection Method Based on a Circumferential Eddy Current Array Sensor

    Directory of Open Access Journals (Sweden)

    Huayu Zhang

    2017-07-01

    Full Text Available To efficiently inspect surface defects on steel ball bearings, a new method based on a circumferential eddy current array (CECA sensor was proposed here. The best probe configuration, in terms of the coil quality factor (Q-factor, magnetic field intensity, and induced eddy current density on the surface of a sample steel ball, was determined using 3-, 4-, 5-, and 6-coil probes, for analysis and comparison. The optimal lift-off from the measured steel ball, the number of probe coils, and the frequency of excitation current suitable for steel ball inspection were obtained. Using the resulting CECA sensor to inspect 46,126 steel balls showed a miss rate of ~0.02%. The sensor was inspected for surface defects as small as 0.05 mm in width and 0.1 mm in depth.

  20. A simple iterative method for estimating evapotranspiration with integrated surface/subsurface flow models

    Science.gov (United States)

    Hwang, H.-T.; Park, Y.-J.; Frey, S. K.; Berg, S. J.; Sudicky, E. A.

    2015-12-01

    This work presents an iterative, water balance based approach to estimate actual evapotranspiration (ET) with integrated surface/subsurface flow models. Traditionally, groundwater level fluctuation methods have been widely accepted and used for estimating ET and net groundwater recharge; however, in watersheds where interactions between surface and subsurface flow regimes are highly dynamic, the traditional method may be overly simplistic. Here, an innovative methodology is derived and demonstrated for using the water balance equation in conjunction with a fully-integrated surface and subsurface hydrologic model (HydroGeoSphere) in order to estimate ET at watershed and sub-watershed scales. The method invokes a simple and robust iterative numerical solution. For the proof of concept demonstrations, the method is used to estimate ET for a simple synthetic watershed and then for a real, highly-characterized 7000 km2 watershed in Southern Ontario, Canada (Grand River Watershed). The results for the Grand River Watershed show that with three to five iterations, the solution converges to a result where there is less than 1% relative error in stream flow calibration at 16 stream gauging stations. The spatially-averaged ET estimated using the iterative method shows a high level of agreement (R2 = 0.99) with that from a benchmark case simulated with an ET model embedded directly in HydroGeoSphere. The new approach presented here is applicable to any watershed that is suited for integrated surface water/groundwater flow modelling and where spatially-averaged ET estimates are useful for calibrating modelled stream discharge.