Surface characterization of nanomaterials and nanoparticles: Important needs and challenging opportunities

International Nuclear Information System (INIS)

Baer, Donald R.; Engelhard, Mark H.; Johnson, Grant E.; Laskin, Julia; Lai, Jinfeng; Mueller, Karl; Munusamy, Prabhakaran; Thevuthasan, Suntharampillai; Wang, Hongfei; Washton, Nancy; Elder, Alison; Baisch, Brittany L.; Karakoti, Ajay; Kuchibhatla, Satyanarayana V. N. T.; Moon, DaeWon

2013-01-01

This review examines characterization challenges inherently associated with understanding nanomaterials and the roles surface and interface characterization methods can play in meeting some of the challenges. In parts of the research community, there is growing recognition that studies and published reports on the properties and behaviors of nanomaterials often have reported inadequate or incomplete characterization. As a consequence, the true value of the data in these reports is, at best, uncertain. With the increasing importance of nanomaterials in fundamental research and technological applications, it is desirable that researchers from the wide variety of disciplines involved recognize the nature of these often unexpected challenges associated with reproducible synthesis and characterization of nanomaterials, including the difficulties of maintaining desired materials properties during handling and processing due to their dynamic nature. It is equally valuable for researchers to understand how characterization approaches (surface and otherwise) can help to minimize synthesis surprises and to determine how (and how quickly) materials and properties change in different environments. Appropriate application of traditional surface sensitive analysis methods (including x-ray photoelectron and Auger electron spectroscopies, scanning probe microscopy, and secondary ion mass spectroscopy) can provide information that helps address several of the analysis needs. In many circumstances, extensions of traditional data analysis can provide considerably more information than normally obtained from the data collected. Less common or evolving methods with surface selectivity (e.g., some variations of nuclear magnetic resonance, sum frequency generation, and low and medium energy ion scattering) can provide information about surfaces or interfaces in working environments (operando or in situ) or information not provided by more traditional methods. Although these methods may

Integrated use of surface geophysical methods for site characterization — A case study in North Kingstown, Rhode Island

Science.gov (United States)

Johnson, Carole D.; Lane, John W.; Brandon, William C.; Williams, Christine A.P.; White, Eric A.

2010-01-01

A suite of complementary, non‐invasive surface geophysical methods was used to assess their utility for site characterization in a pilot investigation at a former defense site in North Kingstown, Rhode Island. The methods included frequency‐domain electromagnetics (FDEM), ground‐penetrating radar (GPR), electrical resistivity tomography (ERT), and multi‐channel analysis of surface‐wave (MASW) seismic. The results of each method were compared to each other and to drive‐point data from the site. FDEM was used as a reconnaissance method to assess buried utilities and anthropogenic structures; to identify near‐surface changes in water chemistry related to conductive leachate from road‐salt storage; and to investigate a resistive signature possibly caused by groundwater discharge. Shallow anomalies observed in the GPR and ERT data were caused by near‐surface infrastructure and were consistent with anomalies observed in the FDEM data. Several parabolic reflectors were observed in the upper part of the GPR profiles, and a fairly continuous reflector that was interpreted as bedrock could be traced across the lower part of the profiles. MASW seismic data showed a sharp break in shear wave velocity at depth, which was interpreted as the overburden/bedrock interface. The MASW profile indicates the presence of a trough in the bedrock surface in the same location where the ERT data indicate lateral variations in resistivity. Depths to bedrock interpreted from the ERT, MASW, and GPR profiles were similar and consistent with the depths of refusal identified in the direct‐push wells. The interpretations of data collected using the individual methods yielded non‐unique solutions with considerable uncertainty. Integrated interpretation of the electrical, electromagnetic, and seismic geophysical profiles produced a more consistent and unique estimation of depth to bedrock that is consistent with ground‐truth data at the site. This test case shows that using

Surface characterization of ceramic materials

International Nuclear Information System (INIS)

Somorjai, G.A.; Salmeron, M.

1976-01-01

In recent years several techniques have become available to characterize the structure and chemical composition of surfaces of ceramic materials. These techniques utilize electron scattering and scattering of ions from surfaces. Low-energy electron diffraction is used to determine the surface structure, Auger electron spectroscopy and other techniques of electron spectroscopy (ultraviolet and photoelectron spectroscopies) are employed to determine the composition of the surface. In addition the oxidation state of surface atoms may be determined using these techniques. Ion scattering mass spectrometry and secondary ion mass spectrometry are also useful in characterizing surfaces and their reactions. These techniques, their applications and the results of recent studies are discussed. 12 figures, 52 references, 2 tables

Study of measurement methods of ultrafine aerosols surface-area for characterizing occupational exposure

International Nuclear Information System (INIS)

Bau, S.

2008-12-01

This work aims at improving knowledge on ultrafine aerosols surface-area measurement. Indeed, the development of nano-technologies may lead to occupational exposure to airborne nano-structured particles, which involves a new prevention issue. There is currently no consensus concerning what parameter (mass, surface-area, number) should be measured. However, surface-area could be a relevant metric, since it leads to a satisfying correlation with biological effects when nano-structured particles are inhaled. Hence, an original theoretical work was performed to position the parameter of surface-area in relation to other aerosol characteristics. To investigate measurement techniques of nano-structured aerosols surface-area, the experimental facility CAIMAN (Characterization of Instruments for the Measurement of Aerosols of Nano-particles) was designed and built. Within CAIMAN, it is possible to produce nano-structured aerosols with varying and controlled properties (size, concentration, chemical nature, morphology, state-of-charge), stable and reproducible in time. The generated aerosols were used to experimentally characterize the response of the instruments in study (NSAM and AeroTrak 9000 TSI, LQ1-DC Matter Engineering). The response functions measured with monodisperse aerosols show a good agreement with the corresponding theoretical curves in a large size range, from 15 to 520 nm. Furthermore, hypotheses have been formulated to explain the reasonable biases observed when measuring poly-disperse aerosols. (author)

A simple surface treatment and characterization of AA 6061 aluminum alloy surface for adhesive bonding applications

International Nuclear Information System (INIS)

Saleema, N.; Sarkar, D.K.; Paynter, R.W.; Gallant, D.; Eskandarian, M.

2012-01-01

Highlights: ► A very simple surface treatment method to achieve excellent and durable aluminum adhesive bonding. ► Our method involves simple immersion of aluminum in very dilute NaOH solution at room temperature with no involvement of strong acids or multiple procedures. ► Surface analysis via various surface characterization techniques showed morphological and chemical modifications favorable for obtaining highly durable bond strengths on the treated surface. ► Safe, economical, reproducible and simple method, easily applicable in industries. - Abstract: Structural adhesive bonding of aluminum is widely used in aircraft and automotive industries. It has been widely noted that surface preparation of aluminum surfaces prior to adhesive bonding plays a significant role in improving the strength of the adhesive bond. Surface cleanliness, surface roughness, surface wettability and surface chemistry are controlled primarily by proper surface treatment methods. In this study, we have employed a very simple technique influencing all these criteria by simply immersing aluminum substrates in a very dilute solution of sodium hydroxide (NaOH) and we have studied the effect of varying the treatment period on the adhesive bonding characteristics. A bi-component epoxy adhesive was used to join the treated surfaces and the bond strengths were evaluated via single lap shear (SLS) tests in pristine as well as degraded conditions. Surface morphology, chemistry, crystalline nature and wettability of the NaOH treated surfaces were characterized using various surface analytical tools such as scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDX), optical profilometry, infrared reflection absorption spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and contact angle goniometry. Excellent adhesion characteristics with complete cohesive failure of the adhesive were encountered on the NaOH treated surfaces that are comparable to the benchmark

Topographic characterization of glazed surfaces

International Nuclear Information System (INIS)

Froeberg, Linda; Hupa, Leena

2008-01-01

Detailed characterization of surface microstructure, i.e. phase composition and surface geometry, has become an important criterion of glazed ceramics. Topographic characterization is an important parameter in, e.g. estimating the influence of additional films on the average roughness of a surface. Also, the microscaled and nanoscaled roughnesses correlate with the cleanability and the self-cleaning properties of the surfaces. In this work the surface geometry of several matte glazes were described by topography and roughness as given by whitelight confocal microscopy and atomic force microscopy. Different measuring parameters were compared to justify the usefulness of the techniques in giving a comprehensive description of the surface microstructure. The results suggest that confocal microscopy is well suited for giving reliable topographical parameters for matte surfaces with microscaled crystals in the surfaces. Atomic force microscopy was better suited for smooth surfaces or for describing the local topographic parameters of closely limited areas, e.g. the surroundings of separate crystals in the surface

Topographic characterization of glazed surfaces

Energy Technology Data Exchange (ETDEWEB)

Froeberg, Linda [Process Chemistry Centre, Abo Akademi University, FI-20500 Turku (Finland)], E-mail: lfroberg@abo.fi; Hupa, Leena [Process Chemistry Centre, Abo Akademi University, FI-20500 Turku (Finland)

2008-01-15

Detailed characterization of surface microstructure, i.e. phase composition and surface geometry, has become an important criterion of glazed ceramics. Topographic characterization is an important parameter in, e.g. estimating the influence of additional films on the average roughness of a surface. Also, the microscaled and nanoscaled roughnesses correlate with the cleanability and the self-cleaning properties of the surfaces. In this work the surface geometry of several matte glazes were described by topography and roughness as given by whitelight confocal microscopy and atomic force microscopy. Different measuring parameters were compared to justify the usefulness of the techniques in giving a comprehensive description of the surface microstructure. The results suggest that confocal microscopy is well suited for giving reliable topographical parameters for matte surfaces with microscaled crystals in the surfaces. Atomic force microscopy was better suited for smooth surfaces or for describing the local topographic parameters of closely limited areas, e.g. the surroundings of separate crystals in the surface.

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.

Surface characterization protocol for precision aspheric optics

Science.gov (United States)

Sarepaka, RamaGopal V.; Sakthibalan, Siva; Doodala, Somaiah; Panwar, Rakesh S.; Kotaria, Rajendra

2017-10-01

In Advanced Optical Instrumentation, Aspherics provide an effective performance alternative. The aspheric fabrication and surface metrology, followed by aspheric design are complementary iterative processes for Precision Aspheric development. As in fabrication, a holistic approach of aspheric surface characterization is adopted to evaluate actual surface error and to aim at the deliverance of aspheric optics with desired surface quality. Precision optical surfaces are characterized by profilometry or by interferometry. Aspheric profiles are characterized by contact profilometers, through linear surface scans to analyze their Form, Figure and Finish errors. One must ensure that, the surface characterization procedure does not add to the resident profile errors (generated during the aspheric surface fabrication). This presentation examines the errors introduced post-surface generation and during profilometry of aspheric profiles. This effort is to identify sources of errors and is to optimize the metrology process. The sources of error during profilometry may be due to: profilometer settings, work-piece placement on the profilometer stage, selection of zenith/nadir points of aspheric profiles, metrology protocols, clear aperture - diameter analysis, computational limitations of the profiler and the software issues etc. At OPTICA, a PGI 1200 FTS contact profilometer (Taylor-Hobson make) is used for this study. Precision Optics of various profiles are studied, with due attention to possible sources of errors during characterization, with multi-directional scan approach for uniformity and repeatability of error estimation. This study provides an insight of aspheric surface characterization and helps in optimal aspheric surface production methodology.

Characterization of holding brake friction pad surface after pin-on-plate wear test

Science.gov (United States)

Drago, N.; Gonzalez Madruga, D.; De Chiffre, L.

2018-03-01

This article concerns the metrological characterization of the surface on a holding brake friction material pin after a pin-on-plate (POP) wear test. The POP test induces the formation of surface plateaus that affect brake performances such as wear, friction, noise and heat. Three different materials’ surfaces have been characterized after wear from data obtained with a focus variation 3D microscope. A new surface characterization approach with plateau identification is proposed, using the number of plateau on the surface, equivalent diameter, length and breadth as measurands. The identification method is based on determining and imposing ISO 27158-2 lower plateau limit (LPL) in material probability curves; and on applying a combined criterion of height segmentation threshold and equivalent diameter threshold. The method determines the criterion thresholds for each material since LPL appears typical by material. The proposed method has allowed quantifying the surface topography at two different levels of wear. An expanded measurement uncertainty of 3.5 µm for plateau dimensions in the range 50–2000 µm and one of 0.15 µm for plateau heights up to 10 µm have been documented.

Preparation of surface enhanced Raman substrate and its characterization

Science.gov (United States)

Liu, Y.; Wang, J. Y.; Wang, J. Q.

2017-10-01

Surface enhanced Raman spectroscopy (SERS) is a fast, convenient and highly sensitive detection technique, and preparing the good effect and repeatable substrate is the key to realize the trace amount and quantitative detection in the field of food safety detection. In this paper, a surface enhanced Raman substrate based on submicrometer silver particles structure was prepared by chemical deposition method, and characterized its structure and optical properties.

Characterization and robust filtering of multifunctional surfaces using ISO standards

DEFF Research Database (Denmark)

Friis, Kasper Storgaard; Godi, Alessandro; De Chiffre, Leonardo

2011-01-01

Engineered surfaces containing lubrication pockets and directional surface texture can decrease wear and friction in sliding or rolling contacts. A new generation of multifunctional (MUFU) surfaces has been created by hard machining followed by robot-assisted polishing. The production method allows...... for a large degree of freedom in specifying surface topography defined by frequency, depth and volume of the lubricant retention valleys, as well as the amount of load bearing area and the surface roughness. The surfaces cannot readily be characterized by means of conventional roughness parameters due...

Preparation and surface characterization of plasma-treated and biomolecular-micropatterned polymer substrates

Science.gov (United States)

Langowski, Bryan Alfred

A micropatterning process creates distinct microscale domains on substrate surfaces that differ from the surfaces' original chemical/physical properties. Numerous micropatterning methods exist, each having relative advantages and disadvantages in terms of cost, ease, reproducibility, and versatility. Polymeric surfaces micropatterned with biomolecules have many applications, but are specifically utilized in tissue engineering as cell scaffolds that attempt to controlled tissue generation in vivo and ex vivo. As the physical and chemical cues presented by micropatterned substrates control resulting cellular behavior, characterization of these cues via surface-sensitive analytical techniques is essential in developing cell scaffolds that mimic complex in vivo physicochemical environments. The initial focus of this thesis is the chemical and physical characterization of plasma-treated, microcontact-printed (muCP) polymeric substrates used to direct nerve cell behavior. Unmodified and oxygen plasma-treated poly(methyl methacrylate) (PMMA) substrates were analyzed by surface sensitive techniques to monitor plasma-induced chemical and physical modifications. Additionally, protein-micropattern homogeneity and size were microscopically evaluated. Lastly, poly(dimethylsiloxane) (PDMS) stamps and contaminated PMMA substrates were characterized by spectroscopic and microscopic methods to identify a contamination source during microcontact printing. The final focus of this thesis is the development of microscale plasma-initiated patterning (muPIP) as a versatile, reproducible micropatterning method. Using muPIP, polymeric substrates were micropatterned with several biologically relevant inks. Polymeric substrates were characterized following muPIP by surface-sensitive techniques to identify the technique's underlying physical and chemical bases. In addition, neural stem cell response to muPIP-generated laminin micropatterns was microscopically and biologically evaluated

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.

Wavelet-fractal approach to surface characterization of nanocrystalline ITO thin films

International Nuclear Information System (INIS)

Raoufi, Davood; Kalali, Zahra

2012-01-01

In this study, indium tin oxide (ITO) thin films were prepared by electron beam deposition method on glass substrates at room temperature (RT). Surface morphology characterization of ITO thin films, before and after annealing at 500 °C, were investigated by analyzing the surface profile of atomic force microscopy (AFM) images using wavelet transform formalism. The wavelet coefficients related to the thin film surface profiles have been calculated, and then roughness exponent (α) of the films has been estimated using the scalegram method. The results reveal that the surface profiles of the films before and after annealing process have self-affine nature.

Map of natural gamma radiation in Spain: radiometric characterization of different types of surfaces

International Nuclear Information System (INIS)

Suarez Mahou, E.; Fernandez Amigot, J.A.; Botas Medina, J.

1997-01-01

The gamma radioactivity flowing from ground and rocks is due to the presence in these of uranium, thorium and potassium-40. The method of radiometric characterization depends on the purpose of the undertaking. Radiometric characterization can be realized on big surfaces (tens or hundreds of square kilometres studied on a national scale), medium size surfaces (50 to 1000 square kilometres, for example, in epidemiological or biological studies in areas with a determined radiometric background) small surfaces of less than 50 square kilometres (industrial sites, pre-operational studies, etc.). This article considers aspects of radiometric characterization on surfaces of interest and describes the contribution of the MARNA (Natural Provisional Radiation Map of Spain) Project selection and radiometric characterization

Evaluation of shot peened surfaces using characterization technique of three-dimensional surface topography

International Nuclear Information System (INIS)

Kurokawa, S; Ariura, Y

2005-01-01

Objective parameters to characterize global topography of three-dimensional surfaces have been derived. The idea of this evaluation is to separate the topography into two global form deviations and residual ones according to the degree of curved surfaces. A shot peened Almen strip is measured by profilometer and concrete parameters of inclination and circular-arc shaped global topography are extracted using the characterization technique. The arc height is calculated using the circular arc-shaped part and compared with a value measured by an Almen gauge. The relation between the coverage and roughness parameters is also investigated. The advantage of this evaluation is that it is possible to determine the arc height and the coverage at the same time from single measured topography. In addition, human error can be excluded from measurement results. This method has the wide application in the field of measurement

SU-F-BRA-09: New Efficient Method for Xoft Axxent Electronic Brachytherapy Source Calibration by Pre-Characterizing Surface Applicators

Energy Technology Data Exchange (ETDEWEB)

Pai, S [iCAD Inc., Los Gatos, CA (United States)

2015-06-15

Purpose: The objective is to improve the efficiency and efficacy of Xoft™ Axxent™ electronic brachytherapy (EBT) calibration of the source & surface applicator using AAPM TG-61 formalism. Methods: Current method of Xoft EBT source calibration involves determination of absolute dose rate of the source in each of the four conical surface applicators using in-air chamber measurements & TG61 formalism. We propose a simplified TG-61 calibration methodology involving initial characterization of surface cone applicators. This is accomplished by calibrating dose rates for all 4 surface applicator sets (for 10 sources) which establishes the “applicator output ratios” with respect to the selected reference applicator (20 mm applicator). After the initial time, Xoft™ Axxent™ source TG61 Calibration is carried out only in the reference applicator. Using the established applicator output ratios, dose rates for other applicators will be calculated. Results: 200 sources & 8 surface applicator sets were calibrated cumulatively using a Standard Imaging A20 ion-chamber in accordance with manufacturer-recommended protocols. Dose rates of 10, 20, 35 & 50mm applicators were normalized to the reference (20mm) applicator. The data in Figure 1 indicates that the normalized dose rate variation for each applicator for all 200 sources is better than ±3%. The average output ratios are 1.11, 1.02 and 0.49 for the 10 mm,35 mm and 50 mm applicators, respectively, which are in good agreement with the manufacturer’s published output ratios of 1.13, 1.02 and 0.49. Conclusion: Our measurements successfully demonstrate the accuracy of a new calibration method using a single surface applicator for Xoft EBT sources and deriving the dose rates of other applicators. The accuracy of the calibration is improved as this method minimizes the source position variation inside the applicator during individual source calibrations. The new method significantly reduces the calibration time to less

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

Science.gov (United States)

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

2015-11-03

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.

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.

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

2015-07-14

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.

Current characterization methods for cellulose nanomaterials.

Science.gov (United States)

Foster, E Johan; Moon, Robert J; Agarwal, Umesh P; Bortner, Michael J; Bras, Julien; Camarero-Espinosa, Sandra; Chan, Kathleen J; Clift, Martin J D; Cranston, Emily D; Eichhorn, Stephen J; Fox, Douglas M; Hamad, Wadood Y; Heux, Laurent; Jean, Bruno; Korey, Matthew; Nieh, World; Ong, Kimberly J; Reid, Michael S; Renneckar, Scott; Roberts, Rose; Shatkin, Jo Anne; Simonsen, John; Stinson-Bagby, Kelly; Wanasekara, Nandula; Youngblood, Jeff

2018-04-23

A new family of materials comprised of cellulose, cellulose nanomaterials (CNMs), having properties and functionalities distinct from molecular cellulose and wood pulp, is being developed for applications that were once thought impossible for cellulosic materials. Commercialization, paralleled by research in this field, is fueled by the unique combination of characteristics, such as high on-axis stiffness, sustainability, scalability, and mechanical reinforcement of a wide variety of materials, leading to their utility across a broad spectrum of high-performance material applications. However, with this exponential growth in interest/activity, the development of measurement protocols necessary for consistent, reliable and accurate materials characterization has been outpaced. These protocols, developed in the broader research community, are critical for the advancement in understanding, process optimization, and utilization of CNMs in materials development. This review establishes detailed best practices, methods and techniques for characterizing CNM particle morphology, surface chemistry, surface charge, purity, crystallinity, rheological properties, mechanical properties, and toxicity for two distinct forms of CNMs: cellulose nanocrystals and cellulose nanofibrils.

The characterization methods for colloids in aqueous solutions

International Nuclear Information System (INIS)

Vuorinen, U.; Kumpulainen, H.

1993-11-01

This literature review deals with characterization methods for colloids in aqueous solutions and in groundwater. The basis for the review has been the needs of nuclear waste disposal studies and methods applicable in such studies. The methods considered include non-destructive laserspectroscopic methods (e.g. TRLFS, LPAS, PALS), several separation methods (e.g. ultrafiltration, dialysis, electrophoresis, field-flow-fractionation) and also some surface analytical methods, as well as some other methods giving additional information on formation and migration properties of colloids. (au.) (71 refs., 13 figs., 3 tabs.)

Nanoscale surface characterization using laser interference microscopy

Science.gov (United States)

Ignatyev, Pavel S.; Skrynnik, Andrey A.; Melnik, Yury A.

2018-03-01

Nanoscale surface characterization is one of the most significant parts of modern materials development and application. The modern microscopes are expensive and complicated tools, and its use for industrial tasks is limited due to laborious sample preparation, measurement procedures, and low operation speed. The laser modulation interference microscopy method (MIM) for real-time quantitative and qualitative analysis of glass, metals, ceramics, and various coatings has a spatial resolution of 0.1 nm for vertical and up to 100 nm for lateral. It is proposed as an alternative to traditional scanning electron microscopy (SEM) and atomic force microscopy (AFM) methods. It is demonstrated that in the cases of roughness metrology for super smooth (Ra >1 nm) surfaces the application of a laser interference microscopy techniques is more optimal than conventional SEM and AFM. The comparison of semiconductor test structure for lateral dimensions measurements obtained with SEM and AFM and white light interferometer also demonstrates the advantages of MIM technique.

Characterization of triboelectrically charged particles deposited on dielectric surfaces

Science.gov (United States)

Nesterov, A.; Löffler, F.; Cheng, Yun-Chien; Torralba, G.; König, K.; Hausmann, M.; Lindenstruth, V.; Stadler, V.; Bischoff, F. R.; Breitling, F.

2010-04-01

A device for the measurement of q/m-values and charge degradation of triboelectrically charged particles deposited on a surface was developed. The setup is based on the integration of currents, which are induced in a Faraday cage by insertion of a solid support covered with charged particles. The conductivity of different particle supports was taken into account. The 'blow-off' method, in which the particles are first deposited, and then blown off using an air stream, can be used for characterization of triboelectric properties of particles relative to different surfaces.

Characterization of triboelectrically charged particles deposited on dielectric surfaces

Energy Technology Data Exchange (ETDEWEB)

Nesterov, A; Torralba, G; Hausmann, M; Lindenstruth, V [Kirchhoff Institute of Physics, In Neuenheimer Feld 227, Heidelberg (Germany); Loeffler, F; Cheng, Yun-Chien; Koenig, K; Stadler, V; Bischoff, F R [German Cancer Research Centre, In Neuenheimer Feld 280, Heidelberg (Germany); Breitling, F, E-mail: Frank.Breitling@KIT.ed, E-mail: alexander.nesterov-mueller@kit.ed [Karlsruhe Institute of Technology (KIT), Institute for Microstructure Technology, Herrmann von Helmholtzplatz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2010-04-28

A device for the measurement of q/m-values and charge degradation of triboelectrically charged particles deposited on a surface was developed. The setup is based on the integration of currents, which are induced in a Faraday cage by insertion of a solid support covered with charged particles. The conductivity of different particle supports was taken into account. The 'blow-off' method, in which the particles are first deposited, and then blown off using an air stream, can be used for characterization of triboelectric properties of particles relative to different surfaces.

Derivatization, characterization, and tribological behavior of an amine-terminated polymer surface

International Nuclear Information System (INIS)

Ren, S.L.; Yang, S.R.; Zhao, Y.P.

2004-01-01

The derivatization, characterization, and micro-tribological behavior of an amine-terminated polymer surface were investigated. Thus, the heptafluorobutyric anhydride (HFBA) derivatized film was characterized by means of contact-angle measurement and X-ray photoelectron spectroscopy (XPS). It was found that the HFBA-derivatized film was generated on the PEI surface in the presence of a chemical amide bond. The tribological properties were characterized as well. The polymer PEI film had relative high adhesion, friction, and poor anti-wear ability, while the HFBA-derivatized polymer film possessed a very low adhesive force of only about 5.5 nN (a pyramidal Si 3 N 4 tip with radius of curvature about 50 nm was used to measure the adhesion), which was more than an order of magnitude lower than that of the silicon substrate surface. Besides, the HFBA-derivatized film registered good friction-reducing ability and thermal stability. Thus, a good alternative method was presented to improve the tribological properties of polymer film by chemisorbing molecules with low surface energy. This makes it feasible for the derivatized polymer film to find promising application in resolving the tribological problems of micro-electromechanical systems (MEMS)

Characterization of polymer surface structure and surface mechanical behaviour by sum frequency generation surface vibrational spectroscopy and atomic force microscopy

International Nuclear Information System (INIS)

Opdahl, Aric; Koffas, Telly S; Amitay-Sadovsky, Ella; Kim, Joonyeong; Somorjai, Gabor A

2004-01-01

Sum frequency generation (SFG) vibrational spectroscopy and atomic force microscopy (AFM) have been used to study polymer surface structure and surface mechanical behaviour, specifically to study the relationships between the surface properties of polymers and their bulk compositions and the environment to which the polymer is exposed. The combination of SFG surface vibrational spectroscopy and AFM has been used to study surface segregation behaviour of polyolefin blends at the polymer/air and polymer/solid interfaces. SFG surface vibrational spectroscopy and AFM experiments have also been performed to characterize the properties of polymer/liquid and polymer/polymer interfaces, focusing on hydrogel materials. A method was developed to study the surface properties of hydrogel contact lens materials at various hydration conditions. Finally, the effect of mechanical stretching on the surface composition and surface mechanical behaviour of phase-separated polyurethanes, used in biomedical implant devices, has been studied by both SFG surface vibrational spectroscopy and AFM. (topical review)

Fabrication and surface characterization of photopatterned encapsulated micromagnets for microrobotics and microfluidics applications

Science.gov (United States)

Li, Hui; Leachman, William; Kershaw, Joe

2016-11-01

In this paper, encapsulated micromagnets with magnetic core surrounded by pure SU-8 were fabricated utilizing multilayer photolithography with a middle NdFeB magnetic composite layer. Various geometries of micromagnets were fabricated with high density magnetic core and high resolution features, showing magnetically response while still being biocompatible and chemically resistant and making them suitable for a wide range of microrobotics and microfluidics applications. Especially, crescent and C-channel micromagnets showed potential of microtransportation devices because of their interior reservoirs. Surface characterization of the micromagnets was conducted using closed-form solutions derived from the general biplanar surface characterization method. The fabrication method was evaluated and the process errors were found less than 1%.

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.

Characterization of electrochemically modified polycrystalline platinum surfaces

Energy Technology Data Exchange (ETDEWEB)

Krebs, L.C.; Ishida, Takanobu.

1991-12-01

The characterization of electrochemically modified polycrystalline platinum surfaces has been accomplished through the use of four major electrochemical techniques. These were chronoamperometry, chronopotentiommetry, cyclic voltammetry, and linear sweep voltammetry. A systematic study on the under-potential deposition of several transition metals has been performed. The most interesting of these were: Ag, Cu, Cd, and Pb. It was determined, by subjecting the platinum electrode surface to a single potential scan between {minus}0.24 and +1.25 V{sub SCE} while stirring the solution, that the electrocatalytic activity would be regenerated. As a consequence of this study, a much simpler method for producing ultra high purity water from acidic permanganate has been developed. This method results in water that surpasses the water produced by pyrocatalytic distillation. It has also been seen that the wettability of polycrystalline platinum surfaces is greatly dependent on the quantity of oxide present. Oxide-free platinum is hydrophobic and gives a contact angle in the range of 55 to 62 degrees. We have also modified polycrystalline platinum surface with the electrically conducting polymer poly-{rho}-phenylene. This polymer is very stable in dilute sulfuric acid solutions, even under applied oxidative potentials. It is also highly resistant to electrochemical hydrogenation. The wettability of the polymer modified platinum surface is severely dependent on the choice of supporting electrolyte chosen for the electrochemical polymerization. Tetraethylammonium tetrafluoroborate produces a film that is as hydrophobic as Teflon, whereas tetraethylammonium perchlorate produces a film that is more hydrophilic than oxide-free platinum.

Characterization of electrochemically modified polycrystalline platinum surfaces

Energy Technology Data Exchange (ETDEWEB)

Krebs, Leonard C. [State Univ. of New York (SUNY), Stony Brook, NY (United States); Ishida, Takanobu [State Univ. of New York (SUNY), Stony Brook, NY (United States)

1991-12-01

The characterization of electrochemically modified polycrystalline platinum surfaces has been accomplished through the use of four major electrochemical techniques. These were chronoamperometry, chronopotentiommetry, cyclic voltammetry, and linear sweep voltammetry. A systematic study on the under-potential deposition of several transition metals has been performed. The most interesting of these were: Ag, Cu, Cd, and Pb. It was determined, by subjecting the platinum electrode surface to a single potential scan between -0.24 and +1.25 V_SCE while stirring the solution, that the electrocatalytic activity would be regenerated. As a consequence of this study, a much simpler method for producing ultra high purity water from acidic permanganate has been developed. This method results in water that surpasses the water produced by pyrocatalytic distillation. It has also been seen that the wettability of polycrystalline platinum surfaces is greatly dependent on the quantity of oxide present. Oxide-free platinum is hydrophobic and gives a contact angle in the range of 55 to 62 degrees. We have also modified polycrystalline platinum surface with the electrically conducting polymer poly-ρ-phenylene. This polymer is very stable in dilute sulfuric acid solutions, even under applied oxidative potentials. It is also highly resistant to electrochemical hydrogenation. The wettability of the polymer modified platinum surface is severely dependent on the choice of supporting electrolyte chosen for the electrochemical polymerization. Tetraethylammonium tetrafluoroborate produces a film that is as hydrophobic as Teflon, whereas tetraethylammonium perchlorate produces a film that is more hydrophilic than oxide-free platinum.

Characterizing Surfaces of the Wide Bandgap Semiconductor Ilmenite with Scanning Probe Microcopies

Science.gov (United States)

Wilkins, R.; Powell, Kirk St. A.

1997-01-01

Ilmenite (FeTiO3) is a wide bandgap semiconductor with an energy gap of about 2.5eV. Initial radiation studies indicate that ilmenite has properties suited for radiation tolerant applications, as well as a variety of other electronic applications. Two scanning probe microscopy methods have been used to characterize the surface of samples taken from Czochralski grown single crystals. The two methods, atomic force microscopy (AFM) and scanning tunneling microscopy (STM), are based on different physical principles and therefore provide different information about the samples. AFM provides a direct, three-dimensional image of the surface of the samples, while STM give a convolution of topographic and electronic properties of the surface. We will discuss the differences between the methods and present preliminary data of each method for ilmenite samples.

Characterizing Pavement Surface Distress Conditions with Hyper-Spatial Resolution Natural Color Aerial Photography

Directory of Open Access Journals (Sweden)

Su Zhang

2016-05-01

Full Text Available Roadway pavement surface distress information is critical for effective pavement asset management, and subsequently, transportation management agencies at all levels (i.e., federal, state, and local dedicate a large amount of time and money to routinely evaluate pavement surface distress conditions as the core of their asset management programs. However, currently adopted ground-based evaluation methods for pavement surface conditions have many disadvantages, like being time-consuming and expensive. Aircraft-based evaluation methods, although getting more attention, have not been used for any operational evaluation programs yet because the acquired images lack the spatial resolution to resolve finer scale pavement surface distresses. Hyper-spatial resolution natural color aerial photography (HSR-AP provides a potential method for collecting pavement surface distress information that can supplement or substitute for currently adopted evaluation methods. Using roadway pavement sections located in the State of New Mexico as an example, this research explored the utility of aerial triangulation (AT technique and HSR-AP acquired from a low-altitude and low-cost small-unmanned aircraft system (S-UAS, in this case a tethered helium weather balloon, to permit characterization of detailed pavement surface distress conditions. The Wilcoxon Signed Rank test, Mann-Whitney U test, and visual comparison were used to compare detailed pavement surface distress rates measured from HSR-AP derived products (orthophotos and digital surface models generated from AT with reference distress rates manually collected on the ground using standard protocols. The results reveal that S-UAS based hyper-spatial resolution imaging and AT techniques can provide detailed and reliable primary observations suitable for characterizing detailed pavement surface distress conditions comparable to the ground-based manual measurement, which lays the foundation for the future application

Antimicrobial characterization of silver nanoparticle-coated surfaces by “touch test” method

Directory of Open Access Journals (Sweden)

Gunell M

2017-11-01

Full Text Available Marianne Gunell,1,2 Janne Haapanen,3 Kofi J Brobbey,4 Jarkko J Saarinen,4 Martti Toivakka,4 Jyrki M Mäkelä,3 Pentti Huovinen,1 Erkki Eerola1,2 1Department of Medical Microbiology and Immunology, University of Turku, 2Department of Clinical Microbiology and Immunology, Microbiology and Genetics Service Area, Turku University Hospital, Turku, 3Aerosol Physics Laboratory, Department of Physics, Tampere University of Technology, Tampere, 4Laboratory of Paper Coating and Converting, Center for Functional Materials, Åbo Akademi University, Turku, Finland Abstract: Bacterial infections, especially by antimicrobial resistant (AMR bacteria, are an increasing problem worldwide. AMR is especially a problem with health care-associated infections due to bacteria in hospital environments being easily transferred from patient to patient and from patient to environment, and thus, solutions to prevent bacterial transmission are needed. Hand washing is an effective tool for preventing bacterial infections, but other approaches such as nanoparticle-coated surfaces are also needed. In the current study, direct and indirect liquid flame spray (LFS method was used to produce silver nanoparticle-coated surfaces. The antimicrobial properties of these nanoparticle surfaces were evaluated with the “touch test” method against Escherichia coli and Staphylococcus aureus. It was shown in this study that in glass samples one silver nanoparticle-coating cycle can inhibit E. coli growth, whereas at least two coating cycles were needed to inhibit S. aureus growth. Silver nanoparticle-coated polyethylene (PE and PE terephthalate samples did not inhibit bacterial growth as effectively as glass samples: three nanoparticle-coating cycles were needed to inhibit E. coli growth, and more than 30 coating cycles were needed until S. aureus growth was inhibited. To conclude, with the LFS method, it is possible to produce nanostructured large-area antibacterial surfaces which show

Surface characterization of graphene based materials

Science.gov (United States)

Pisarek, M.; Holdynski, M.; Krawczyk, M.; Nowakowski, R.; Roguska, A.; Malolepszy, A.; Stobinski, L.; Jablonski, A.

2016-12-01

In the present study, two kind of samples were used: (i) a monolayer graphene film with a thickness of 0.345 nm deposited by the CVD method on Cu foil, (ii) graphene flakes obtained by modified Hummers method and followed by reduction of graphene oxide. The inelastic mean free path (IMFP), characterizing electron transport in graphene/Cu sample and reduced graphene oxide material, which determines the sampling depth of XPS and AES were evaluated from relative Elastic Peak Electron Spectroscopy (EPES) measurements with the Au standard in the energy range 0.5-2 keV. The measured IMFPs were compared with IMFPs resulting from experimental optical data published in the literature for the graphite sample. The EPES IMFP values at 0.5 and 1.5 keV was practically identical to that calculated from optical data for graphite (less than 4% deviation). For energies 1 and 2 keV, the EPES IMFPs for rGO were deviated up to 14% from IMFPs calculated using the optical data by Tanuma et al. [1]. Before EPES measurements all samples were characterized by various techniques like: FE-SEM, AFM, XPS, AES and REELS to visualize the surface morphology/topography and identify the chemical composition.

Surface characterization and stability of an epoxy resin surface modified with polyamines grafted on polydopamine

Energy Technology Data Exchange (ETDEWEB)

Schaubroeck, David, E-mail: David.Schaubroeck@elis.ugent.be [Center for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 914A, B-9052 Ghent (Belgium); Vercammen, Yannick; Van Vaeck, Luc [Biomolecular and Analytical Mass Spectrometry, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Vanderleyden, Els; Dubruel, Peter [Polymer Chemistry and Biomaterials Research Group, Ghent University, Krijgslaan 281 S4 bis, B-9000 Ghent (Belgium); Vanfleteren, Jan [Center for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 914A, B-9052 Ghent (Belgium)

2014-06-01

This paper reports on polydopamine and polyamine surface modifications of an etched epoxy cresol novolac (ECN) resin using the ‘grafting to’ method. Three different polyamines are used for the grafting reactions: branched polyethyleneimine (B-PEI), linear polyethyleneimine (L-PEI) and diethylenetriamine (DETA). These modifications are compared to control materials prepared via direct deposition of polyamines. The stability of the modifications toward a concentrated hydrochloric acid (HCl) environment is evaluated. The modified surfaces are characterized with scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and time-of-flight static secondary ion mass spectroscopy (TOF-S-SIMS).

Characterization of a surface dielectric barrier discharge

NARCIS (Netherlands)

Pemen, A.J.M.; Beckers, F.J.C.M.; Heesch, van E.J.M.

2009-01-01

A surface dielectric barrier discharge (SDBD) reactor provides a homogeneous plasma over a large surface area. This allows surface treatments of foils, textiles or fibers. Here we present results of a study to characterize the AC and pulsed performance of SDBD with regard to ozone production,

uleSIMS characterization of silver reference surfaces

Science.gov (United States)

Palitsin, V. V.; Dowsett, M. G.; Mata, B. Guzmán de la; Oloff, I. W.; Gibbons, R.

2006-07-01

Ultra low energy SIMS (uleSIMS) is a high sensitivity analytical technique that is normally used for ultra shallow profiling at a depth resolution of up to1 nm. This work describes the use of uleSIMS as both a spectroscopic and depth-profiling tool for the characterization of the early stages of corrosion formed on reference surfaces of silver. These samples are being developed to help with the characterization of tarnished surfaces in a cultural heritage context, and uleSIMS enables the tarnishing to be studied from its very earliest stages due to its high sensitivity (ppm-ppb) and surface specificity. We show that, uleSIMS can be used effectively to study the surface chemistry and aid the development of reference surfaces themselves. In particular, handling contaminants, surface dust, and residues from polishing are relatively easy to identify allowing them to be separated from the parts of the mass spectrum specific to the early stages of corrosion.

National Nanotechnology Laboratory (LNNano) open facilities for scientific community: new methods for polymeric materials characterization

International Nuclear Information System (INIS)

Silva, Cristiane A.; Santos, Ramon H.Z. dos; Bernardes, Juliana S.; Gouveia, Rubia F.

2015-01-01

National Nanotechnology Laboratory (LNNano) at the National Center for Energy and Materials (CNPEM) presents open facilities for scientific public in some areas. In this work will be discussed the facilities for mainly the polymeric community, as well as new methods for the characterization. Low density polyethylene (LDPE) surfaces were characterized by X-ray microtomography and X-ray photoelectron spectroscopy (XPS). The results obtained by microtomography have shown that these surfaces present different contrasts when compared with the bulk. These differences are correlated with the formation of an oxidized layer at the polymer surface, which consequently have a greater X-ray attenuation. This hypothesis is confirmed by XPS, which shows LDPE surface layers are richer in carbonyl, carboxyl and vinyl groups than the bulk. This work presents that microtomography can be used as a new method for detection and characterization of polymer surface oxidation. (author)

Surface characterization of graphene based materials

International Nuclear Information System (INIS)

Pisarek, M.; Holdynski, M.; Krawczyk, M.; Nowakowski, R.; Roguska, A.; Malolepszy, A.; Stobinski, L.; Jablonski, A.

2016-01-01

Highlights: • Two kind of samples: commercial graphene on Cu substrate and rGO flakes. • EPES applied to measure the IMFPs in graphene based materials. • Characterization by various techniques like: FE-SEM, AFM, XPS, AES and REELS. • EPES IMFPs for rGO deviated up to 14% from IMFPs calculated using the optical data. - Abstract: In the present study, two kind of samples were used: (i) a monolayer graphene film with a thickness of 0.345 nm deposited by the CVD method on Cu foil, (ii) graphene flakes obtained by modified Hummers method and followed by reduction of graphene oxide. The inelastic mean free path (IMFP), characterizing electron transport in graphene/Cu sample and reduced graphene oxide material, which determines the sampling depth of XPS and AES were evaluated from relative Elastic Peak Electron Spectroscopy (EPES) measurements with the Au standard in the energy range 0.5–2 keV. The measured IMFPs were compared with IMFPs resulting from experimental optical data published in the literature for the graphite sample. The EPES IMFP values at 0.5 and 1.5 keV was practically identical to that calculated from optical data for graphite (less than 4% deviation). For energies 1 and 2 keV, the EPES IMFPs for rGO were deviated up to 14% from IMFPs calculated using the optical data by Tanuma et al. [1]. Before EPES measurements all samples were characterized by various techniques like: FE-SEM, AFM, XPS, AES and REELS to visualize the surface morphology/topography and identify the chemical composition.

Surface characterization of graphene based materials

Energy Technology Data Exchange (ETDEWEB)

Pisarek, M., E-mail: mpisarek@ichf.edu.pl [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland); Holdynski, M.; Krawczyk, M.; Nowakowski, R.; Roguska, A. [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland); Malolepszy, A. [Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warynskiego 1, 00-065 Warsaw (Poland); Stobinski, L. [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland); Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warynskiego 1, 00-065 Warsaw (Poland); Jablonski, A. [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland)

2016-12-01

Highlights: • Two kind of samples: commercial graphene on Cu substrate and rGO flakes. • EPES applied to measure the IMFPs in graphene based materials. • Characterization by various techniques like: FE-SEM, AFM, XPS, AES and REELS. • EPES IMFPs for rGO deviated up to 14% from IMFPs calculated using the optical data. - Abstract: In the present study, two kind of samples were used: (i) a monolayer graphene film with a thickness of 0.345 nm deposited by the CVD method on Cu foil, (ii) graphene flakes obtained by modified Hummers method and followed by reduction of graphene oxide. The inelastic mean free path (IMFP), characterizing electron transport in graphene/Cu sample and reduced graphene oxide material, which determines the sampling depth of XPS and AES were evaluated from relative Elastic Peak Electron Spectroscopy (EPES) measurements with the Au standard in the energy range 0.5–2 keV. The measured IMFPs were compared with IMFPs resulting from experimental optical data published in the literature for the graphite sample. The EPES IMFP values at 0.5 and 1.5 keV was practically identical to that calculated from optical data for graphite (less than 4% deviation). For energies 1 and 2 keV, the EPES IMFPs for rGO were deviated up to 14% from IMFPs calculated using the optical data by Tanuma et al. [1]. Before EPES measurements all samples were characterized by various techniques like: FE-SEM, AFM, XPS, AES and REELS to visualize the surface morphology/topography and identify the chemical composition.

Geophysical methods for fracture characterization in and around potential sites for nuclear waste disposal

International Nuclear Information System (INIS)

Majer, E.L.; Lee, K.H.; Morrison, H.F.

1992-08-01

Historically, geophysical methods have been used extensively to successfully explore the subsurface for petroleum, gas, mineral, and geothermal resources. Their application, however, for site characterization, and monitoring the performance of near surface waste sites or repositories has been somewhat limited. Presented here is an overview of the geophysical methods that could contribute to defining the subsurface heterogeneity and extrapolating point measurements at the surface and in boreholes to volumetric descriptions in a fractured rock. In addition to site characterization a significant application of geophysical methods may be in performance assessment and in monitoring the repository to determine if the performance is as expected

Analytical Methods for Biomass Characterization during Pretreatment and Bioconversion

Energy Technology Data Exchange (ETDEWEB)

Pu, Yunqiao [ORNL; Meng, Xianzhi [University of Tennessee, Knoxville (UTK); Yoo, Chang Geun; Li, Mi; Ragauskas, Arthur J [ORNL

2016-01-01

Lignocellulosic biomass has been introduced as a promising resource for alternative fuels and chemicals because of its abundance and complement for petroleum resources. Biomass is a complex biopolymer and its compositional and structural characteristics largely vary depending on its species as well as growth environments. Because of complexity and variety of biomass, understanding its physicochemical characteristics is a key for effective biomass utilization. Characterization of biomass does not only provide critical information of biomass during pretreatment and bioconversion, but also give valuable insights on how to utilize the biomass. For better understanding biomass characteristics, good grasp and proper selection of analytical methods are necessary. This chapter introduces existing analytical approaches that are widely employed for biomass characterization during biomass pretreatment and conversion process. Diverse analytical methods using Fourier transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR) spectroscopy for biomass characterization are reviewed. In addition, biomass accessibility methods by analyzing surface properties of biomass are also summarized in this chapter.

A plateau–valley separation method for textured surfaces with a deterministic pattern

DEFF Research Database (Denmark)

Godi, Alessandro; Kühle, Anders; De Chiffre, Leonardo

2014-01-01

The effective characterization of textured surfaces presenting a deterministic pattern of lubricant reservoirs is an issue with which many researchers are nowadays struggling. Existing standards are not suitable for the characterization of such surfaces, providing at times values without physical...... meaning. A new method based on the separation between the plateau and valley regions is hereby presented allowing independent functional analyses of the detected features. The determination of a proper threshold between plateaus and valleys is the first step of a procedure resulting in an efficient...

Layer-by-Layer Method for the Synthesis and Growth of Surface Mounted Metal-Organic Frameworks (SURMOFs

Directory of Open Access Journals (Sweden)

Osama Shekhah

2010-02-01

Full Text Available A layer-by-layer method has been developed for the synthesis of metal-organic frameworks (MOFs and their deposition on functionalized organic surfaces. The approach is based on the sequential immersion of functionalized organic surfaces into solutions of the building blocks of the MOF, i.e., the organic ligand and the inorganic unit. The synthesis and growth of different types of MOFs on substrates with different functionalization, like COOH, OH and pyridine terminated surfaces, were studied and characterized with different surface characterization techniques. A controlled and highly oriented growth of very homogenous films was obtained using this method. The layer-by-layer method offered also the possibility to study the kinetics of film formation in more detail using surface plasmon resonance and quartz crystal microbalance. In addition, this method demonstrates the potential to synthesize new classes of MOFs not accessible by conventional methods. Finally, the controlled growth of MOF thin films is important for many applications like chemical sensors, membranes and related electrodes.

Error characterization methods for surface soil moisture products from remote sensing

International Nuclear Information System (INIS)

Doubková, M.

2012-01-01

To support the operational use of Synthetic Aperture Radar (SAR) earth observation systems, the European Space Agency (ESA) is developing Sentinel-1 radar satellites operating in C-band. Much like its SAR predecessors (Earth Resource Satellite, ENVISAT, and RADARSAT), the Sentinel-1 will operate at a medium spatial resolution (ranging from 5 to 40 m), but with a greatly improved revisit period, especially over Europe (∼2 days). Given the planned high temporal sampling and the operational configuration Sentinel-1 is expected to be beneficial for operational monitoring of dynamic processes in hydrology and phenology. The benefit of a C-band SAR monitoring service in hydrology has already been demonstrated within the scope of the Soil Moisture for Hydrometeorologic Applications (SHARE) project using data from the Global Mode (GM) of the Advanced Synthetic Aperture Radar (ASAR). To fully exploit the potential of the SAR soil moisture products, well characterized error needs to be provided with the products. Understanding errors of remotely sensed surface soil moisture (SSM) datasets was indispensible for their application in models, for extractions of blended SSM products, as well as for their usage in evaluation of other soil moisture datasets. This thesis has several objectives. First, it provides the basics and state of the art methods for evaluating measures of SSM, including both the standard (e.g. Root Mean Square Error, Correlation coefficient) and the advanced (e.g. Error propagation, Triple collocation) evaluation measures. A summary of applications of soil moisture datasets is presented and evaluation measures are suggested for each application according to its requirement on the dataset quality. The evaluation of the Advanced Synthetic Aperture Radar (ASAR) Global Mode (GM) SSM using the standard and advanced evaluation measures comprises a second objective of the work. To achieve the second objective, the data from the Australian Water Assessment System

Surface characterization of modern resin composites: a multitechnique approach.

Science.gov (United States)

Silikas, Nick; Kavvadia, Katerina; Eliades, George; Watts, David

2005-04-01

To characterize the surface properties of some modern resin composites employing a series of physicochemical methods. Specimens from three microhybrid (Palfique Estellite-PE, Z250 Filtek-ZF, Tetric Ceram-TC) and one nanofilled (Supreme Filtek-SF) conventionally photo-cured resin composites polished with Soflex disks were studied for the following properties: Surface chemical composition and degree of C=C conversion (FTIR), surface energetics (contact angles), surface texture (AFM), surface roughness (AFM, stylus profilometry) and gloss (60 degrees-, 20 degrees-angle specular gloss). Polar and non polar molecular groups were identified in all products including NH and CONH (SF, ZF, TC). SF and ZF demonstrated higher conversion than PE and TC (P 0.05) were found in critical surface tension, total work of adhesion and its polar and dispersion components, the latter being the highest in all products. AFM showed the smoothest surface texture in PE. The ranking of Sa, Sq, Ra and Rz roughness parameters was PEgloss measurements (PE, SF>ZF>TC, PTC, Pgloss differences. A positive correlation was found between Sa and Ra and a negative one between Sa and 20 degree-angle gloss.

Near-surface thermal characterization of plasma facing components using the 3-omega method

International Nuclear Information System (INIS)

Dechaumphai, Edward; Barton, Joseph L.; Tesmer, Joseph R.; Moon, Jaeyun; Wang, Yongqiang; Tynan, George R.; Doerner, Russell P.; Chen, Renkun

2014-01-01

Near-surface regime plays an important role in thermal management of plasma facing components in fusion reactors. Here, we applied a technique referred to as the ‘3ω’ method to measure the thermal conductivity of near-surface regimes damaged by ion irradiation. By modulating the frequency of the heating current in a micro-fabricated heater strip, the technique enables the probing of near-surface thermal properties. The technique was applied to measure the thermal conductivity of a thin ion-irradiated layer on a tungsten substrate, which was found to decrease by nearly 60% relative to pristine tungsten for a Cu ion dosage of 0.2 dpa

Surface characterization of low-temperature grown yttrium oxide

Science.gov (United States)

Krawczyk, Mirosław; Lisowski, Wojciech; Pisarek, Marcin; Nikiforow, Kostiantyn; Jablonski, Aleksander

2018-04-01

The step-by-step growth of yttrium oxide layer was controlled in situ using X-ray photoelectron spectroscopy (XPS). The O/Y atomic concentration (AC) ratio in the surface layer of finally oxidized Y substrate was found to be equal to 1.48. The as-grown yttrium oxide layers were then analyzed ex situ using combination of Auger electron spectroscopy (AES), elastic-peak electron spectroscopy (EPES) and scanning electron microscopy (SEM) in order to characterize their surface chemical composition, electron transport phenomena and surface morphology. Prior to EPES measurements, the Y oxide surface was pre-sputtered by 3 kV argon ions, and the resulting AES-derived composition was found to be Y0.383O0.465C0.152 (O/Y AC ratio of 1.21). The SEM images revealed different surface morphology of sample before and after Ar sputtering. The oxide precipitates were observed on the top of un-sputtered Y oxide layer, whereas the oxide growth at the Ar ion-sputtered surface proceeded along defects lines normal to the layer plane. The inelastic mean free path (IMFP) characterizing electron transport was evaluated as a function of energy in the range of 0.5-2 keV from the EPES method. Two reference materials (Ni and Au) were used in these measurements. Experimental IMFPs determined for the Y0.383O0.465C0.152 and Y2O3 surface compositions, λ, were uncorrected for surface excitations and approximated by the simple function λ = kEp at electron energies E between 500 eV and 2000 eV, where k and p were fitted parameters. These values were also compared with IMFPs resulting from the TPP-2 M predictive equation for both oxide compositions. The fitted functions were found to be reasonably consistent with the measured and predicted IMFPs. In both cases, the average value of the mean percentage deviation from the fits varied between 5% and 37%. The IMFPs measured for Y0.383O0.465C0.152 surface composition were found to be similar to the IMFPs for Y2O3.

Advanced Fine Particulate Characterization Methods

Energy Technology Data Exchange (ETDEWEB)

Steven Benson; Lingbu Kong; Alexander Azenkeng; Jason Laumb; Robert Jensen; Edwin Olson; Jill MacKenzie; A.M. Rokanuzzaman

2007-01-31

The characterization and control of emissions from combustion sources are of significant importance in improving local and regional air quality. Such emissions include fine particulate matter, organic carbon compounds, and NO{sub x} and SO{sub 2} gases, along with mercury and other toxic metals. This project involved four activities including Further Development of Analytical Techniques for PM{sub 10} and PM{sub 2.5} Characterization and Source Apportionment and Management, Organic Carbonaceous Particulate and Metal Speciation for Source Apportionment Studies, Quantum Modeling, and High-Potassium Carbon Production with Biomass-Coal Blending. The key accomplishments included the development of improved automated methods to characterize the inorganic and organic components particulate matter. The methods involved the use of scanning electron microscopy and x-ray microanalysis for the inorganic fraction and a combination of extractive methods combined with near-edge x-ray absorption fine structure to characterize the organic fraction. These methods have direction application for source apportionment studies of PM because they provide detailed inorganic analysis along with total organic and elemental carbon (OC/EC) quantification. Quantum modeling using density functional theory (DFT) calculations was used to further elucidate a recently developed mechanistic model for mercury speciation in coal combustion systems and interactions on activated carbon. Reaction energies, enthalpies, free energies and binding energies of Hg species to the prototype molecules were derived from the data obtained in these calculations. Bimolecular rate constants for the various elementary steps in the mechanism have been estimated using the hard-sphere collision theory approximation, and the results seem to indicate that extremely fast kinetics could be involved in these surface reactions. Activated carbon was produced from a blend of lignite coal from the Center Mine in North Dakota and

Facet Model and Mathematical Morphology for Surface Characterization

Energy Technology Data Exchange (ETDEWEB)

Abidi, B.R.; Goddard, J.S.; Hunt, M.A.; Sari-Sarraf, H.

1999-11-13

This paper describes an algorithm for the automatic segmentation and representation of surface structures and non-uniformities in an industrial setting. The automatic image processing and analysis algorithm is developed as part of a complete on-line web characterization system of a papermaking process at the wet end. The goal is to: (1) link certain types of structures on the surface of the web to known machine parameter values, and (2) find the connection between detected structures at the beginning of the line and defects seen on the final product. Images of the pulp mixture (slurry), carried by a fast moving table, are obtained using a stroboscopic light and a CCD camera. This characterization algorithm succeeded where conventional contrast and edge detection techniques failed due to a poorly controlled environment. The images obtained have poor contrast and contain noise caused by a variety of sources. After a number of enhancement steps, conventional segmentation methods still f ailed to detect any structures and are consequently discarded. Techniques tried include the Canny edge detector, the Sobel, Roberts, and Prewitt's filters, as well as zero crossings. The facet model algorithm, is then applied to the images with various parameter settings and is found to be successful in detecting the various topographic characteristics of the surface of the slurry. Pertinent topographic elements are retained and a filtered image computed. Carefully tailored morphological operators are then applied to detect and segment regions of interest. Those regions are then selected according to their size, elongation, and orientation. Their bounding rectangles are computed and represented. Also addressed in this paper are aspects of the real time implementation of this algorithm for on-line use. The algorithm is tested on over 500 images of slurry and is found to segment and characterize nonuniformities on all 500 images.

Experimental Study in Taguchi Method on Surface Quality Predication of HSM

Science.gov (United States)

Ji, Yan; Li, Yueen

2018-05-01

Based on the study of ball milling mechanism and machining surface formation mechanism, the formation of high speed ball-end milling surface is a time-varying and cumulative Thermos-mechanical coupling process. The nature of this problem is that the uneven stress field and temperature field affect the machined surface Process, the performance of the processing parameters in the processing interaction in the elastic-plastic materials produced by the elastic recovery and plastic deformation. The surface quality of machining surface is characterized by multivariable nonlinear system. It is still an indispensable and effective method to study the surface quality of high speed ball milling by experiments.

Atomic force microscopy characterization of the surface wettability of natural fibres

International Nuclear Information System (INIS)

Pietak, Alexis; Korte, Sandra; Tan, Emelyn; Downard, Alison; Staiger, Mark P.

2007-01-01

Natural fibres represent a readily available source of ecologically friendly and inexpensive reinforcement in composites with degradable thermoplastics, however chemical treatments of fibres are required to prepare feasible composites. It is desirable to characterize the surface wettability of fibres after chemical treatment as the polarity of cellulose-based fibres influences compatibility with a polymer matrix. Assessment of the surface wettability of natural fibres using conventional methods presents a challenge as the surfaces are morphologically and chemically heterogeneous, rough, and can be strongly wicking. In this work it is shown that under atmospheric conditions the adhesion force between an atomic force microscopy (AFM) tip and the fibre surface can estimate the water contact angle and surface wettability of the fibre. AFM adhesion force measurements are suitable for the more difficult surfaces of natural fibres and in addition allow for correlations between microstructural features and surface wettability characteristics

Tracer Methods for Characterizing Fracture Creation in Engineered Geothermal Systems

Energy Technology Data Exchange (ETDEWEB)

Rose, Peter [Energy & Geoscience Institute at the University of Utah, Salt Lake City, UT (United States); Harris, Joel [Univ. of Utah, Salt Lake City, UT (United States)

2014-05-08

The aim of this proposal is to develop, through novel high-temperature-tracing approaches, three technologies for characterizing fracture creation within Engineered Geothermal Systems (EGS). The objective of a first task is to identify, develop and demonstrate adsorbing tracers for characterizing interwell reservoir-rock surface areas and fracture spacing. The objective of a second task is to develop and demonstrate a methodology for measuring fracture surface areas adjacent to single wells. The objective of a third task is to design, fabricate and test an instrument that makes use of tracers for measuring fluid flow between newly created fractures and wellbores. In one method of deployment, it will be used to identify qualitatively which fractures were activated during a hydraulic stimulation experiment. In a second method of deployment, it will serve to measure quantitatively the rate of fluid flowing from one or more activated fracture during a production test following a hydraulic stimulation.

Scattered surface charge density: A tool for surface characterization

KAUST Repository

Naydenov, Borislav

2011-11-28

We demonstrate the use of nonlocal scanning tunneling spectroscopic measurements to characterize the local structure of adspecies in their states where they are significantly less perturbed by the probe, which is accomplished by mapping the amplitude and phase of the scattered surface charge density. As an example, we study single-H-atom adsorption on the n-type Si(100)-(4 × 2) surface, and demonstrate the existence of two different configurations that are distinguishable using the nonlocal approach and successfully corroborated by density functional theory. © 2011 American Physical Society.

Scattered surface charge density: A tool for surface characterization

KAUST Repository

Naydenov, Borislav; Mantega, Mauro; Rungger, Ivan; Sanvito, Stefano; Boland, John J.

2011-01-01

We demonstrate the use of nonlocal scanning tunneling spectroscopic measurements to characterize the local structure of adspecies in their states where they are significantly less perturbed by the probe, which is accomplished by mapping the amplitude and phase of the scattered surface charge density. As an example, we study single-H-atom adsorption on the n-type Si(100)-(4 × 2) surface, and demonstrate the existence of two different configurations that are distinguishable using the nonlocal approach and successfully corroborated by density functional theory. © 2011 American Physical Society.

Formation and Characterization of Stacked Nanoscale Layers of Polymers and Silanes on Silicon Surfaces

Science.gov (United States)

Ochoa, Rosie; Davis, Brian; Conley, Hiram; Hurd, Katie; Linford, Matthew R.; Davis, Robert C.

2008-10-01

Chemical surface patterning at the nanoscale is a critical component of chemically directed assembly of nanoscale devices or sensitive biological molecules onto surfaces. Complete and consistent formation of nanoscale layers of silanes and polymers is a necessary first step for chemical patterning. We explored methods of silanizing silicon substrates for the purpose of functionalizing the surfaces. The chemical functionalization, stability, flatness, and repeatability of the process was characterized by use of ellipsometry, water contact angle, and Atomic Force Microscopy (AFM). We found that forming the highest quality functionalized surfaces was accomplished through use of chemical vapor deposition (CVD). Specifically, surfaces were plasma cleaned and hydrolyzed before the silane was applied. A polymer layer less then 2 nm in thickness was electrostatically bound to the silane layer. The chemical functionalization, stability, flatness, and repeatability of the process was also characterized for the polymer layer using ellipsometry, water contact angle, and AFM.

Surface microstructure of bitumen characterized by atomic force microscopy.

Science.gov (United States)

Yu, Xiaokong; Burnham, Nancy A; Tao, Mingjiang

2015-04-01

Bitumen, also called asphalt binder, plays important roles in many industrial applications. It is used as the primary binding agent in asphalt concrete, as a key component in damping systems such as rubber, and as an indispensable additive in paint and ink. Consisting of a large number of hydrocarbons of different sizes and polarities, together with heteroatoms and traces of metals, bitumen displays rich surface microstructures that affect its rheological properties. This paper reviews the current understanding of bitumen's surface microstructures characterized by Atomic Force Microscopy (AFM). Microstructures of bitumen develop to different forms depending on crude oil source, thermal history, and sample preparation method. While some bitumens display surface microstructures with fine domains, flake-like domains, and dendrite structuring, 'bee-structures' with wavy patterns several micrometers in diameter and tens of nanometers in height are commonly seen in other binders. Controversy exists regarding the chemical origin of the 'bee-structures', which has been related to the asphaltene fraction, the metal content, or the crystallizing waxes in bitumen. The rich chemistry of bitumen can result in complicated intermolecular associations such as coprecipitation of wax and metalloporphyrins in asphaltenes. Therefore, it is the molecular interactions among the different chemical components in bitumen, rather than a single chemical fraction, that are responsible for the evolution of bitumen's diverse microstructures, including the 'bee-structures'. Mechanisms such as curvature elasticity and surface wrinkling that explain the rippled structures observed in polymer crystals might be responsible for the formation of 'bee-structures' in bitumen. Despite the progress made on morphological characterization of bitumen using AFM, the fundamental question whether the microstructures observed on bitumen surfaces represent its bulk structure remains to be addressed. In addition

Surface characterization of nickel titanium orthodontic arch wires

Science.gov (United States)

Krishnan, Manu; Seema, Saraswathy; Tiwari, Brijesh; Sharma, Himanshu S.; Londhe, Sanjay; Arora, Vimal

2015-01-01

Background Surface roughness of nickel titanium orthodontic arch wires poses several clinical challenges. Surface modification with aesthetic/metallic/non metallic materials is therefore a recent innovation, with clinical efficacy yet to be comprehensively evaluated. Methods One conventional and five types of surface modified nickel titanium arch wires were surface characterized with scanning electron microscopy, energy dispersive analysis, Raman spectroscopy, Atomic force microscopy and 3D profilometry. Root mean square roughness values were analyzed by one way analysis of variance and post hoc Duncan's multiple range tests. Results Study groups demonstrated considerable reduction in roughness values from conventional in a material specific pattern: Group I; conventional (578.56 nm) > Group V; Teflon (365.33 nm) > Group III; nitride (301.51 nm) > Group VI (i); rhodium (290.64 nm) > Group VI (ii); silver (252.22 nm) > Group IV; titanium (229.51 nm) > Group II; resin (158.60 nm). It also showed the defects with aesthetic (resin/Teflon) and nitride surfaces and smooth topography achieved with metals; titanium/silver/rhodium. Conclusions Resin, Teflon, titanium, silver, rhodium and nitrides were effective in decreasing surface roughness of nickel titanium arch wires albeit; certain flaws. Findings have clinical implications, considering their potential in lessening biofilm adhesion, reducing friction, improving corrosion resistance and preventing nickel leach and allergic reactions. PMID:26843749

Surface modification and characterization of basalt fibers as potential reinforcement of concretes

Science.gov (United States)

Iorio, M.; Santarelli, M. L.; González-Gaitano, G.; González-Benito, J.

2018-01-01

Basalt fibers were surface treated with silane coupling agents as a method to enhance the adhesion and durability of fiber-matrix interfaces in concrete based composite materials. In particular, this work has been focused on the study of basalt fibers chemical coatings with aminosilanes and their subsequent characterization. Surface treatments were carried out after removing the original sizing applied by manufacturer and pretreating them with an activation process of surface silanol regeneration. Different samples were considered to make convenient comparisons: as received fibers (commercial), calcinated fibers (without commercial sizing), activated samples (calcinated fibers subjected to an acid process for hydroxyl regeneration), and silanized fibers with γ-aminopropiltriethoxysilane, γ-aminopropilmethyldiethoxysilane and a mixture of 50% by weight of both silanes. A deep characterization was carried out in terms of structure using X-ray diffraction, XRD, and Fourier transform infrared spectroscopy, FTIR, thermal properties by thermogravimetric analysis, TGA, coupled with single differential thermal analysis, SDTA, and morphology by scanning electron microscopy, SEM, and atomic force microscopy, AFM.

Metrological evaluation of characterization methods applied to nuclear fuels

International Nuclear Information System (INIS)

Faeda, Kelly Cristina Martins; Lameiras, Fernando Soares; Camarano, Denise das Merces; Ferreira, Ricardo Alberto Neto; Migliorini, Fabricio Lima; Carneiro, Luciana Capanema Silva; Silva, Egonn Hendrigo Carvalho

2010-01-01

In manufacturing the nuclear fuel, characterizations are performed in order to assure the minimization of harmful effects. The uranium dioxide is the most used substance as nuclear reactor fuel because of many advantages, such as: high stability even when it is in contact with water at high temperatures, high fusion point, and high capacity to retain fission products. Several methods are used for characterization of nuclear fuels, such as thermogravimetric analysis for the ratio O / U, penetration-immersion method, helium pycnometer and mercury porosimetry for the density and porosity, BET method for the specific surface, chemical analyses for relevant impurities, and the laser flash method for thermophysical properties. Specific tools are needed to control the diameter and the sphericity of the microspheres and the properties of the coating layers (thickness, density, and degree of anisotropy). Other methods can also give information, such as scanning and transmission electron microscopy, X-ray diffraction, microanalysis, and mass spectroscopy of secondary ions for chemical analysis. The accuracy of measurement and level of uncertainty of the resulting data are important. This work describes a general metrological characterization of some techniques applied to the characterization of nuclear fuel. Sources of measurement uncertainty were analyzed. The purpose is to summarize selected properties of UO 2 that have been studied by CDTN in a program of fuel development for Pressurized Water Reactors (PWR). The selected properties are crucial for thermalhydraulic codes to study basic design accidents. The thermal characterization (thermal diffusivity and thermal conductivity) and the penetration immersion method (density and open porosity) of UO 2 samples were focused. The thermal characterization of UO 2 samples was determined by the laser flash method between room temperature and 448 K. The adaptive Monte Carlo Method was used to obtain the endpoints of the

Metrological evaluation of characterization methods applied to nuclear fuels

Energy Technology Data Exchange (ETDEWEB)

Faeda, Kelly Cristina Martins; Lameiras, Fernando Soares; Camarano, Denise das Merces; Ferreira, Ricardo Alberto Neto; Migliorini, Fabricio Lima; Carneiro, Luciana Capanema Silva; Silva, Egonn Hendrigo Carvalho, E-mail: kellyfisica@gmail.co, E-mail: fernando.lameiras@pq.cnpq.b, E-mail: dmc@cdtn.b, E-mail: ranf@cdtn.b, E-mail: flmigliorini@hotmail.co, E-mail: lucsc@hotmail.co, E-mail: egonn@ufmg.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2010-07-01

In manufacturing the nuclear fuel, characterizations are performed in order to assure the minimization of harmful effects. The uranium dioxide is the most used substance as nuclear reactor fuel because of many advantages, such as: high stability even when it is in contact with water at high temperatures, high fusion point, and high capacity to retain fission products. Several methods are used for characterization of nuclear fuels, such as thermogravimetric analysis for the ratio O / U, penetration-immersion method, helium pycnometer and mercury porosimetry for the density and porosity, BET method for the specific surface, chemical analyses for relevant impurities, and the laser flash method for thermophysical properties. Specific tools are needed to control the diameter and the sphericity of the microspheres and the properties of the coating layers (thickness, density, and degree of anisotropy). Other methods can also give information, such as scanning and transmission electron microscopy, X-ray diffraction, microanalysis, and mass spectroscopy of secondary ions for chemical analysis. The accuracy of measurement and level of uncertainty of the resulting data are important. This work describes a general metrological characterization of some techniques applied to the characterization of nuclear fuel. Sources of measurement uncertainty were analyzed. The purpose is to summarize selected properties of UO{sub 2} that have been studied by CDTN in a program of fuel development for Pressurized Water Reactors (PWR). The selected properties are crucial for thermalhydraulic codes to study basic design accidents. The thermal characterization (thermal diffusivity and thermal conductivity) and the penetration immersion method (density and open porosity) of UO{sub 2} samples were focused. The thermal characterization of UO{sub 2} samples was determined by the laser flash method between room temperature and 448 K. The adaptive Monte Carlo Method was used to obtain the endpoints of

Bulk and surface characterization of novel photoresponsive polymeric systems

Science.gov (United States)

Venkataramani, Shivshankar

This dissertation presents a detailed characterization of two important classes of photoresponsive polymers-polydiacetylenes (PDAs) and azopolymers. Bulk and surface characterization techniques were used to evaluate the structure-property relationships of the PDAs and surface characterization, in particular-atomic force microscopy (AFM) was used to characterize the azopolymers. PDAs from bis-alkylurethanes of 5,7 dodecadiyn 1,12-diol (viz.,) ETCD, IPUDO and PUDO are of particular interest in view of reports of reversible thermochromic and photochromic phase transitions in these materials. Thermochromism in the above PDAs is associated with a first order phase transition involving expansion of the crystallographic unit cell, the preservation of the urethane hydrogen bonding and possibly some relief of mechanical strain upon heating. Insights into thermochromism obtained from studies of nonthermochromic forms of PDA-ETCD are discussed. Some of the bulk characterization experiments reported In the literature are repeated. The motivation to investigate the surface morphology of the PDA single crystals using AFM was derived from Raman spectroscopy studies of various PDAs in which dispersion of the Raman spectrum indicating surface heterogeneity was observed. Micron scale as well as molecularly resolved images were obtained The micron scale images indicated a variable surface of the crystals. The molecularly resolved images showed a well defined 2-D lattice and are interpreted in terms of known crystallographic data. The surface parameters obtained from AFM measurements are similar to those determined from X-ray diffraction. During an attempt of AFM imaging of IPUDO crystals exposed to 254 nm ultraviolet light, it was observed that these crystals undergo a "macroscopic shattering". In the interest of rigorously defining conditions for photochromism, this research has undertaken a combined study of the surface morphology of the above mentioned PDA crystals by AFM and the

Pulsed magnetic flux leakage method for hairline crack detection and characterization

Science.gov (United States)

Okolo, Chukwunonso K.; Meydan, Turgut

2018-04-01

The Magnetic Flux leakage (MFL) method is a well-established branch of electromagnetic Non-Destructive Testing (NDT), extensively used for evaluating defects both on the surface and far-surface of pipeline structures. However the conventional techniques are not capable of estimating their approximate size, location and orientation, hence an additional transducer is required to provide the extra information needed. This research is aimed at solving the inevitable problem of granular bond separation which occurs during manufacturing, leaving pipeline structures with miniature cracks. It reports on a quantitative approach based on the Pulsed Magnetic Flux Leakage (PMFL) method, for the detection and characterization of the signals produced by tangentially oriented rectangular surface and far-surface hairline cracks. This was achieved through visualization and 3D imaging of the leakage field. The investigation compared finite element numerical simulation with experimental data. Experiments were carried out using a 10mm thick low carbon steel plate containing artificial hairline cracks with various depth sizes, and different features were extracted from the transient signal. The influence of sensor lift-off and pulse width variation on the magnetic field distribution which affects the detection capability of various hairline cracks located at different depths in the specimen is explored. The findings show that the proposed technique can be used to classify both surface and far-surface hairline cracks and can form the basis for an enhanced hairline crack detection and characterization for pipeline health monitoring.

Morphological Characterization of Nanofibers: Methods and Application in Practice

Directory of Open Access Journals (Sweden)

Jakub Širc

2012-01-01

Full Text Available Biomedical applications such as wound dressing for skin regeneration, stem cell transplantation, or drug delivery require special demands on the three-dimensional porous scaffolds. Besides the biocompatibility and mechanical properties, the morphology is the most important attribute of the scaffold. Specific surface area, volume, and size of the pores have considerable effect on cell adhesion, growth, and proliferation. In the case of incorporated biologically active substances, their release is also influenced by the internal structure of nanofibers. Although many scientific papers are focused on the preparation of nanofibers and evaluation of biological tests, the morphological characterization was described just briefly as service methods. The aim of this paper is to summarize the methods applicable for morphological characterization of nanofibers and supplement it by the results of our research. Needleless electrospinning technique was used to prepare nanofibers from polylactide, poly(ε-caprolactone, gelatin, and polyamide. Scanning electron microscopy was used to evaluate the fiber diameters and to reveal eventual artifacts in the nanofibrous structure. Nitrogen adsorption/desorption measurements were employed to measure the specific surface areas. Mercury porosimetry was used to determine total porosities and compare pore size distributions of the prepared samples.

Surface modification and characterization Collaborative Research Center at ORNL

International Nuclear Information System (INIS)

1986-01-01

The Surface Modification and Characterization Collaborative Research Center (SMAC/CRC) is a unique facility for the alteration and characterization of the near-surface properties of materials. The SMAC/CRC facility is equipped with particle accelerators and high-powered lasers which can be used to improve the physical, electrical, and/or chemical properties of solids and to create unique new materials not possible to obtain with conventional ''equilibrium'' processing techniques. Surface modification is achieved using such techniques as ion implantation doping, ion beam mixing, laser mixing, ion deposition, and laser annealing

Electrostatic force microscopy as a broadly applicable method for characterizing pyroelectric materials

International Nuclear Information System (INIS)

Martin-Olmos, Cristina; Gimzewski, James K; Stieg, Adam Z

2012-01-01

A general method based on the combination of electrostatic force microscopy with thermal cycling of the substrate holder is presented for direct, nanoscale characterization of the pyroelectric effect in a range of materials and sample configurations using commercial atomic force microscope systems. To provide an example of its broad applicability, the technique was applied to the examination of natural tourmaline gemstones. The method was validated using thermal cycles similar to those experienced in ambient conditions, where the induced pyroelectric response produced localized electrostatic surface charges whose magnitude demonstrated a correlation with the iron content and heat dissipation of each gemstone variety. In addition, the surface charge was shown to persist even at thermal equilibrium. This behavior is attributed to constant, stochastic cooling of the gemstone surface through turbulent contact with the surrounding air and indicates a potential utility for energy harvesting in applications including environmental sensors and personal electronics. In contrast to previously reported methods, ours has a capacity to carry out such precise nanoscale measurements with little or no restriction on the sample of interest, and represents a powerful new tool for the characterization of pyroelectric materials and devices. (paper)

The surface analysis methods; Les methodes d`analyse des surfaces

Energy Technology Data Exchange (ETDEWEB)

Deville, J.P. [Institut de Physique et Chimie, 67 - Strasbourg (France)

1998-11-01

Nowadays, there are a lot of surfaces analysis methods, each having its specificity, its qualities, its constraints (for instance vacuum) and its limits. Expensive in time and in investment, these methods have to be used deliberately. This article appeals to non specialists. It gives some elements of choice according to the studied information, the sensitivity, the use constraints or the answer to a precise question. After having recalled the fundamental principles which govern these analysis methods, based on the interaction between radiations (ultraviolet, X) or particles (ions, electrons) with matter, two methods will be more particularly described: the Auger electron spectroscopy (AES) and x-rays photoemission spectroscopy (ESCA or XPS). Indeed, they are the most widespread methods in laboratories, the easier for use and probably the most productive for the analysis of surface of industrial materials or samples submitted to treatments in aggressive media. (O.M.) 11 refs.

Surface modification, characterization and adsorptive properties of a coconut activated carbon

Energy Technology Data Exchange (ETDEWEB)

Lu Xincheng [Institute of Chemical Industry of Forest Products, CAF, National Engineering Lab. for Biomass Chemical Utilization, Key and Open Lab. of Forest Chemical Engineering, SFA, Key Lab. of Biomass Energy and Material, Jiangsu Province, Suojin wucun 16, Nanjing 210042 (China); Jiang Jianchun, E-mail: lhs_ac2011@yahoo.cn [Institute of Chemical Industry of Forest Products, CAF, National Engineering Lab. for Biomass Chemical Utilization, Key and Open Lab. of Forest Chemical Engineering, SFA, Key Lab. of Biomass Energy and Material, Jiangsu Province, Suojin wucun 16, Nanjing 210042 (China); Sun Kang; Xie Xinping; Hu Yiming [Institute of Chemical Industry of Forest Products, CAF, National Engineering Lab. for Biomass Chemical Utilization, Key and Open Lab. of Forest Chemical Engineering, SFA, Key Lab. of Biomass Energy and Material, Jiangsu Province, Suojin wucun 16, Nanjing 210042 (China)

2012-08-01

A coconut activated carbon was modified using chemical methods. Different concentration of nitric acid oxidation of the conventional sample produced samples with weakly acidic functional groups. The oxidized samples were characterized by scanning electron micrograph, nitrogen absorption-desorption, Fourier transform infra red spectroscopy, Bothem method, pH titration, adsorption capacity of sodium and formaldehyde, and the adsorption mechanism of activated carbons was investigated. The results showed that BET surface area and pore volume of activated carbons were decreased after oxidization process, while acidic functional groups were increased. The surface morphology of oxidized carbons looked clean and eroded which was caused by oxidization of nitric acid. The oxidized carbons showed high adsorption capacity of sodium and formaldehyde, and chemical properties of activated carbon played an important role in adsorption of metal ions and organic pollutants.

Metrological characterization methods for confocal chromatic line sensors and optical topography sensors

Science.gov (United States)

Seppä, Jeremias; Niemelä, Karri; Lassila, Antti

2018-05-01

The increasing use of chromatic confocal technology for, e.g. fast, in-line optical topography, and measuring thickness, roughness and profiles implies a need for the characterization of various aspects of the sensors. Single-point, line and matrix versions of chromatic confocal technology, encoding depth information into wavelength, have been developed. Of these, line sensors are particularly suitable for in-line process measurement. Metrological characterization and development of practical methods for calibration and checking is needed for new optical methods and devices. Compared to, e.g. tactile methods, optical topography measurement techniques have limitations related to light wavelength and coherence, optical properties of the sample including reflectivity, specularity, roughness and colour, and definition of optical versus mechanical surfaces. In this work, metrological characterization methods for optical line sensors were developed for scale magnification and linearity, sensitivity to sample properties, and dynamic characteristics. An accurate depth scale calibration method using a single prototype groove depth sample was developed for a line sensor and validated with laser-interferometric sample tracking, attaining (sub)micrometre level or better than 0.1% scale accuracy. Furthermore, the effect of different surfaces and materials on the measurement and depth scale was studied, in particular slope angle, specularity and colour. In addition, dynamic performance, noise, lateral scale and resolution were measured using the developed methods. In the case of the LCI1200 sensor used in this study, which has a 11.3 mm  ×  2.8 mm measurement range, the instrument depth scale was found to depend only minimally on sample colour, whereas measuring steeply sloped specular surfaces in the peripheral measurement area, in the worst case, caused a somewhat larger relative sample-dependent change (1%) in scale.

Characterizing bars in low surface brightness disc galaxies

Science.gov (United States)

Peters, Wesley; Kuzio de Naray, Rachel

2018-05-01

In this paper, we use B-band, I-band, and 3.6 μm azimuthal light profiles of four low surface brightness galaxies (LSBs; UGC 628, F568-1, F568-3, F563-V2) to characterize three bar parameters: length, strength, and corotation radius. We employ three techniques to measure the radius of the bars, including a new method using the azimuthal light profiles. We find comparable bar radii between the I-band and 3.6 μm for all four galaxies when using our azimuthal light profile method, and that our bar lengths are comparable to those in high surface brightness galaxies (HSBs). In addition, we find the bar strengths for our galaxies to be smaller than those for HSBs. Finally, we use Fourier transforms of the B-band, I-band, and 3.6 μm images to characterize the bars as either `fast' or `slow' by measuring the corotation radius via phase profiles. When using the B- and I-band phase crossings, we find three of our galaxies have faster than expected relative bar pattern speeds for galaxies expected to be embedded in centrally dense cold dark matter haloes. When using the B-band and 3.6 μm phase crossings, we find more ambiguous results, although the relative bar pattern speeds are still faster than expected. Since we find a very slow bar in F563-V2, we are confident that we are able to differentiate between fast and slow bars. Finally, we find no relation between bar strength and relative bar pattern speed when comparing our LSBs to HSBs.

Characterization of Pectin Nanocoatings at Polystyrene and Titanium Surfaces

DEFF Research Database (Denmark)

Gurzawska, Katarzyna; Dirscherl, Kai; Yihua, Yu

2013-01-01

. To characterize, compare and visualize the surface nanocoatings measurements of contact angle measurements and surface roughness with atomic force microscopy, scanning electron microscopy, and confocal microscopy was performed. We found that, both unmodified and enzymatic modified RG-Is influenced surface...

Characterization of iron surface modified by 2-mercaptobenzothiazole self-assembled monolayers

Energy Technology Data Exchange (ETDEWEB)

Feng Yuanyuan [Department of Chemistry, Shandong University, Jinan 250100 (China); Chen Shenhao [Department of Chemistry, Shandong University, Jinan 250100 (China) and State Key Laboratory for Corrosion and Protection, Shenyang 110016 (China)]. E-mail: shchen@sdu.edu.cn; Zhang Honglin [Department of Chemistry, Qufu Normal University, Qufu 273165 (China); Li Ping [Department of Chemistry, Shandong University, Jinan 250100 (China); Wu Ling [Department of Chemistry, Shandong University, Jinan 250100 (China); Guo Wenjuan [Department of Chemistry, Shandong University, Jinan 250100 (China)

2006-12-30

A self-assembled monolayer of 2-mercaptobenzothiazole (MBT) adsorbed on the iron surface was prepared. The films were characterized by electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared reflection spectroscopy (FT-IR) and scanning electron microscopy (SEM). Besides, the microcalorimetry method was utilized to study the self-assembled process on iron surface and the adsorption mechanism was discussed from the power-time curve. The results indicated that MBT was able to form a film spontaneously on iron surface and the presence of it could protect iron from corrosion effectively. However, the assembling time and the concentration influence the protection efficiency. Quantum chemical calculations, according to which adsorption mechanism was discussed, could explain the experimental results to some extent.

A Lagrangian cylindrical coordinate system for characterizing dynamic surface geometry of tubular anatomic structures.

Science.gov (United States)

Lundh, Torbjörn; Suh, Ga-Young; DiGiacomo, Phillip; Cheng, Christopher

2018-03-03

Vascular morphology characterization is useful for disease diagnosis, risk stratification, treatment planning, and prediction of treatment durability. To quantify the dynamic surface geometry of tubular-shaped anatomic structures, we propose a simple, rigorous Lagrangian cylindrical coordinate system to monitor well-defined surface points. Specifically, the proposed system enables quantification of surface curvature and cross-sectional eccentricity. Using idealized software phantom examples, we validate the method's ability to accurately quantify longitudinal and circumferential surface curvature, as well as eccentricity and orientation of eccentricity. We then apply the method to several medical imaging data sets of human vascular structures to exemplify the utility of this coordinate system for analyzing morphology and dynamic geometric changes in blood vessels throughout the body. Graphical abstract Pointwise longitudinal curvature of a thoracic aortic endograft surface for systole and diastole, with their absolute difference.

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.

Study on the relevance of some of the description methods for plateau-honed surfaces

International Nuclear Information System (INIS)

Yousfi, M; Mezghani, S; Demirci, I; El Mansori, M

2014-01-01

Much work has been undertaken in recent years into the determination of a complete parametric description of plateau-honed surfaces with the intention of making a link between the process conditions, the surface topography and the required functional performances. Different advanced techniques (plateau/valleys decomposition using the normalized Abbott–Firestone curve or morphological operators, multiscale decomposition using continuous wavelets transform, etc) were proposed and applied in different studies. This paper re-examines the current state of developments and addresses a discussion on the relevance of the different proposed parameters and characterization methods for plateau-honed surfaces by considering the control loop manufacturing-characterization-function. The relevance of appropriate characterization is demonstrated through two experimental studies. They consider the effect of the most plateau honing process variables (the abrasive grit size and abrasive indentation velocity in finish-honing and the plateau-honing stage duration and pressure) on cylinder liner surface textures and hydrodynamic friction of the ring-pack system. (paper)

NMR characterization of hydrocarbon adsorption on calcite surfaces: A first principles study

Energy Technology Data Exchange (ETDEWEB)

Bevilaqua, Rochele C. A.; Miranda, Caetano R. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, UFABC, Santo André, SP (Brazil); Rigo, Vagner A. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, UFABC, Santo André, SP (Brazil); Universidade Tecnológica Federal do Paraná, UTFPR, Cornélio Procópio, PR (Brazil); Veríssimo-Alves, Marcos [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, UFABC, Santo André, SP (Brazil); Departamento de Física, ICEx, Universidade Federal Fluminense, UFF, Volta Redonda, RJ (Brazil)

2014-11-28

The electronic and coordination environment of minerals surfaces, as calcite, are very difficult to characterize experimentally. This is mainly due to the fact that there are relatively few spectroscopic techniques able to detect Ca{sup 2+}. Since calcite is a major constituent of sedimentary rocks in oil reservoir, a more detailed characterization of the interaction between hydrocarbon molecules and mineral surfaces is highly desirable. Here we perform a first principles study on the adsorption of hydrocarbon molecules on calcite surface (CaCO{sub 3} (101{sup ¯}4)). The simulations were based on Density Functional Theory with Solid State Nuclear Magnetic Resonance (SS-NMR) calculations. The Gauge-Including Projector Augmented Wave method was used to compute mainly SS-NMR parameters for {sup 43}Ca, {sup 13}C, and {sup 17}O in calcite surface. It was possible to assign the peaks in the theoretical NMR spectra for all structures studied. Besides showing different chemical shifts for atoms located on different environments (bulk and surface) for calcite, the results also display changes on the chemical shift, mainly for Ca sites, when the hydrocarbon molecules are present. Even though the interaction of the benzene molecule with the calcite surface is weak, there is a clearly distinguishable displacement of the signal of the Ca sites over which the hydrocarbon molecule is located. A similar effect is also observed for hexane adsorption. Through NMR spectroscopy, we show that aromatic and alkane hydrocarbon molecules adsorbed on carbonate surfaces can be differentiated.

Spinorial characterizations of surfaces into 3-dimensional psuedo-Riemannian space forms

OpenAIRE

Lawn , Marie-Amélie; Roth , Julien

2011-01-01

9 pages; We give a spinorial characterization of isometrically immersed surfaces of arbitrary signature into 3-dimensional pseudo-Riemannian space forms. For Lorentzian surfaces, this generalizes a recent work of the first author in $\\mathbb{R}^{2,1}$ to other Lorentzian space forms. We also characterize immersions of Riemannian surfaces in these spaces. From this we can deduce analogous results for timelike immersions of Lorentzian surfaces in space forms of corresponding signature, as well ...

Inverse method for effects characterization from ultrasonic b-scan images

International Nuclear Information System (INIS)

Faur, M.

1999-02-01

In service inspections of French nuclear pressure water reactor vessels are carried out automatically in complete immersion from the inside by means of ultrasonic focused probes working in the pulse echo mode. Concern has been expressed about the capabilities of performing non destructive evaluation of the Outer Surface Defects (OSD), i.e. defects located in the vicinity of the outer surface of the inspected components. OSD are insonified by both a direct field that passes through the inner surface (water/steel) of the component containing the defect and a secondary field reflected from the outer surface. Consequently, the Bscan images, containing the signatures of such defects, are complicated and their interpretation is a difficult task. This work deals with extraction of the maximum available information for characterizing OSD from ultrasonic Bscan images. Our main objectives are to obtain the type of OSD and their geometric parameters by means of two specific inverse methods. The first method is used for the identification of the geometrical parameters of the equivalent planar OSD from segmented Bscan images. Ultrasonic equivalent defect sizing model-based methods may be used to size a defect in a material by obtaining a best-fit simple equivalent shape that matches the ultrasonic observed data. We illustrate the application of such an equivalent sizing OSD method that is based on a simplified direct model. The major drawback of this identification method, as used to date, is that only a part of the useful information contained into original Bscan image, i.e. segmented Bscan image, is used for defect characterization. Moreover, it requires the availability of defect classification information (i.e. if the defect is volumetric or planer, e. g. a crack or a lack of fusion), which, generally, may be as difficult to obtain as the defect parameters themselves. Therefore, we propose a parameter estimation method for extracting complementary information on the defect

The Chameleon Effect: characterization challenges due to the variability of nanoparticles and their surfaces of nanoparticles and their surfaces

Science.gov (United States)

Baer, Donald R.

2018-05-01

Nanoparticles in a variety of forms are increasing important in fundamental research, technological and medical applications, and environmental or toxicology studies. Physical and chemical drivers that lead to multiple types of particle instabilities complicate both the ability to produce, appropriately characterize, and consistently deliver well-defined particles, frequently leading to inconsistencies and conflicts in the published literature. This perspective suggests that provenance information, beyond that often recorded or reported, and application of a set of core characterization methods, including a surface sensitive technique, consistently applied at critical times can serve as tools in the effort minimize reproducibility issues.

Surface characterization of Ag/Titania adsorbents

International Nuclear Information System (INIS)

Samokhvalov, Alexander; Nair, Sachin; Duin, Evert C.; Tatarchuk, Bruce J.

2010-01-01

The Ag/Titania adsorbent for selective removal of the desulfurization-refractive polycyclic aromatic sulfur heterocycles (PASHs) from liquid hydrocarbon fuels was prepared, its total and the Ag specific surface area were determined and the surface reaction sites in the sorbent that may be active in the adsorptive selective desulfurization were characterized by several spectroscopic and surface science techniques. The sorbent contains Ag, Ti, O and spurious C on its surface, as by the XPS measurements. Silver is present as an oxide, as judged by the XPS Auger parameter (AP). The complementary electron spin resonance (ESR) spectroscopy confirms that the majority of Ag is present in the diamagnetic Ag 1+ form, with the minor concentration (∼0.1% of total Ag) present as Ag 2+ . The findings by XPS and ESR are confirmed by the XRD, UV-vis spectroscopy and thermodynamic considerations. The supported Ag is highly dispersed on the surface of the titania support, with the particle size of ∼30-60 A depending on Ag content, with an Ag specific surface area of ∼7-14 m 2 /g, vs. the total surface area of ∼114-58 m 2 /g.

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

KAUST Repository

Liu, Hongyi; Li, Yan; Krause, Wendy E.; Rojas, Orlando J.; Pasquinelli, Melissa A.

2012-01-01

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.

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.

Comparison of Dorris-Gray and Schultz methods for the calculation of surface dispersive free energy by inverse gas chromatography.

Science.gov (United States)

Shi, Baoli; Wang, Yue; Jia, Lina

2011-02-11

Inverse gas chromatography (IGC) is an important technique for the characterization of surface properties of solid materials. A standard method of surface characterization is that the surface dispersive free energy of the solid stationary phase is firstly determined by using a series of linear alkane liquids as molecular probes, and then the acid-base parameters are calculated from the dispersive parameters. However, for the calculation of surface dispersive free energy, generally, two different methods are used, which are Dorris-Gray method and Schultz method. In this paper, the results calculated from Dorris-Gray method and Schultz method are compared through calculating their ratio with their basic equations and parameters. It can be concluded that the dispersive parameters calculated with Dorris-Gray method will always be larger than the data calculated with Schultz method. When the measuring temperature increases, the ratio increases large. Compared with the parameters in solvents handbook, it seems that the traditional surface free energy parameters of n-alkanes listed in the papers using Schultz method are not enough accurate, which can be proved with a published IGC experimental result. © 2010 Elsevier B.V. All rights reserved.

Analysis of atomic force microscopy data for surface characterization using fuzzy logic

International Nuclear Information System (INIS)

Al-Mousa, Amjed; Niemann, Darrell L.; Niemann, Devin J.; Gunther, Norman G.; Rahman, Mahmud

2011-01-01

In this paper we present a methodology to characterize surface nanostructures of thin films. The methodology identifies and isolates nanostructures using Atomic Force Microscopy (AFM) data and extracts quantitative information, such as their size and shape. The fuzzy logic based methodology relies on a Fuzzy Inference Engine (FIE) to classify the data points as being top, bottom, uphill, or downhill. The resulting data sets are then further processed to extract quantitative information about the nanostructures. In the present work we introduce a mechanism which can consistently distinguish crowded surfaces from those with sparsely distributed structures and present an omni-directional search technique to improve the structural recognition accuracy. In order to demonstrate the effectiveness of our approach we present a case study which uses our approach to quantitatively identify particle sizes of two specimens each with a unique gold nanoparticle size distribution. - Research Highlights: → A Fuzzy logic analysis technique capable of characterizing AFM images of thin films. → The technique is applicable to different surfaces regardless of their densities. → Fuzzy logic technique does not require manual adjustment of the algorithm parameters. → The technique can quantitatively capture differences between surfaces. → This technique yields more realistic structure boundaries compared to other methods.

Isolation, screening, and characterization of surface-active agent-producing, oil-degrading marine bacteria of Mumbai Harbor.

Science.gov (United States)

Mohanram, Rajamani; Jagtap, Chandrakant; Kumar, Pradeep

2016-04-15

Diverse marine bacterial species predominantly found in oil-polluted seawater produce diverse surface-active agents. Surface-active agents produced by bacteria are classified into two groups based on their molecular weights, namely biosurfactants and bioemulsifiers. In this study, surface-active agent-producing, oil-degrading marine bacteria were isolated using a modified Bushnell-Haas medium with high-speed diesel as a carbon source from three oil-polluted sites of Mumbai Harbor. Surface-active agent-producing bacterial strains were screened using nine widely used methods. The nineteen bacterial strains showed positive results for more than four surface-active agent screening methods; further, these strains were characterized using biochemical and nucleic acid sequencing methods. Based on the results, the organisms belonged to the genera Acinetobacter, Alcanivorax, Bacillus, Comamonas, Chryseomicrobium, Halomonas, Marinobacter, Nesterenkonia, Pseudomonas, and Serratia. The present study confirmed the prevalence of surface-active agent-producing bacteria in the oil-polluted waters of Mumbai Harbor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Spinorial Characterizations of Surfaces into 3-dimensional Pseudo-Riemannian Space Forms

International Nuclear Information System (INIS)

Lawn, Marie-Amélie; Roth, Julien

2011-01-01

We give a spinorial characterization of isometrically immersed surfaces of arbitrary signature into 3-dimensional pseudo-Riemannian space forms. This generalizes a recent work of the first author for spacelike immersed Lorentzian surfaces in ℝ 2,1 to other Lorentzian space forms. We also characterize immersions of Riemannian surfaces in these spaces. From this we can deduce analogous results for timelike immersions of Lorentzian surfaces in space forms of corresponding signature, as well as for spacelike and timelike immersions of surfaces of signature (0, 2), hence achieving a complete spinorial description for this class of pseudo-Riemannian immersions.

Characterization of ceramic materials - Some methods employed in quality control of nuclear fuels

International Nuclear Information System (INIS)

Cardoso, P.E.; Ferraz, W.B.; Lameiras, F.S.; Lopes, J.A.M.; Santos, A.M.M. dos; Ferreira, R.A.N.

1986-01-01

Measuring methods are presented for specific surface, density, open porosity and microstructure, such as bulk density of particles in form of nicrospheres, for characterization of ceramic materials used as nuclear fuels. Some of these methods are alternatives to those usually employed, and they present some advantages, such as economy, speed of execution, and accuracy. (Author) [pt

Surface science tools for nanomaterials characterization

CERN Document Server

2015-01-01

Fourth volume of a 40volume series on nano science and nanotechnology, edited by the renowned scientist Challa S.S.R. Kumar. This handbook gives a comprehensive overview about Surface Science Tools for Nanomaterials Characterization. Modern applications and state-of-the-art techniques are covered and make this volume an essential reading for research scientists in academia and industry.

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

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.

Method and Apparatus for Characterizing Pressure Sensors using Modulated Light Beam Pressure

Science.gov (United States)

Youngquist, Robert C. (Inventor)

2003-01-01

Embodiments of apparatuses and methods are provided that use light sources instead of sound sources for characterizing and calibrating sensors for measuring small pressures to mitigate many of the problems with using sound sources. In one embodiment an apparatus has a light source for directing a beam of light on a sensing surface of a pressure sensor for exerting a force on the sensing surface. The pressure sensor generates an electrical signal indicative of the force exerted on the sensing surface. A modulator modulates the beam of light. A signal processor is electrically coupled to the pressure sensor for receiving the electrical signal.

Characterization of the intrinsic density profiles for liquid surfaces

International Nuclear Information System (INIS)

Chacon, Enrique; Tarazona, Pedro

2005-01-01

This paper presents recent advances in the characterization of the intrinsic structures in computer simulations of liquid surfaces. The use of operational definitions for the intrinsic surface, associated with each molecular configuration of a liquid slab, gives direct access to the intrinsic profile and to the wavevector dependent surface tension. However, the characteristics of these functions depend on the definition used for the intrinsic surface. We discuss the pathologies associated with a local Gibbs dividing surface definition, and consider the alternative definition of a minimal area surface, going though a set of surface pivots, self-consistently chosen to represent the first liquid layer

Surface modification and characterization of indium-tin oxide for organic light-emitting devices.

Science.gov (United States)

Zhong, Z Y; Jiang, Y D

2006-10-15

In this work, we used different treatment methods (ultrasonic degreasing, hydrochloric acid treatment, and oxygen plasma) to modify the surfaces of indium-tin oxide (ITO) substrates for organic light-emitting devices. The surface properties of treated ITO substrates were studied by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), sheet resistance, contact angle, and surface energy measurements. Experimental results show that the ITO surface properties are closely related to the treatment methods, and the oxygen plasma is more efficient than the other treatments since it brings about smoother surfaces, lower sheet resistance, higher work function, and higher surface energy and polarity of the ITO substrate. Moreover, polymer light-emitting electrochemical cells (PLECs) with differently treated ITO substrates as device electrodes were fabricated and characterized. It is found that surface treatments of ITO substrates have a certain degree of influence upon the injection current, brightness, and efficiency, but hardly upon the turn-on voltages of current injection and light emission, which are in agreement with the measured optical energy gap of the electroluminescent polymer. The oxygen plasma treatment on the ITO substrate yields the best performance of PLECs, due to the improvement of interface formation and electrical contact of the ITO substrate with the polymer blend in the PLECs.

Contribution of multi-temporal remote sensing images to characterize landslide slip surface ‒ Application to the La Clapière landslide (France

Directory of Open Access Journals (Sweden)

B. Casson

2005-01-01

Full Text Available Landslide activity is partly controlled by the geometry of the slip surface. This activity is traduced at the surface by displacements and topographic variations. Consequently, multi-temporal remote sensing images can be used in order to characterize the geometry of landslide slip surface and its spatial and temporal evolution. Differential Digital Elevation Models (DEMs are obtained by subtracting two DEMs of different years. A method of multi-temporal images correlation allows to generate displacement maps that can be interpreted in terms of velocity and direction of movements. These data are then used to characterize qualitatively the geometry of the slip surface of the la Clapière landslide (French Southern Alps. Distribution of displacement vectors and of topographic variations are in accordance with a curved slip surface, characterizing a preferential rotational behaviour of this landslide. On the other hand, a spatial and temporal evolution of the geometry of the slip surface is pointed out. Indeed, a propagation of the slip surface under the Iglière bar, in the W part of the landslide, is suspected and can be linked to the acceleration of the landslide in 1987. This study shows the high potential of multi-temporal remote sensing images for slip surface characterization. Although this method could not replace in situ investigations, it can really help to well distribute geophysical profiles or boreholes on unstable areas.

On-Surface Synthesis and Characterization of Honeycombene Oligophenylene Macrocycles.

Science.gov (United States)

Chen, Min; Shang, Jian; Wang, Yongfeng; Wu, Kai; Kuttner, Julian; Hilt, Gerhard; Hieringer, Wolfgang; Gottfried, J Michael

2017-01-24

We report the on-surface formation and characterization of [30]-honeycombene, a cyclotriacontaphenylene, which consists of 30 phenyl rings (C 180 H 120 ) and has a diameter of 4.0 nm. This shape-persistent, conjugated, and unsubstituted hexagonal hydrocarbon macrocycle was obtained by solvent-free synthesis on a silver (111) single-crystal surface, making solubility-enhancing alkyl side groups unnecessary. Side products include strained macrocycles with square, pentagonal, and heptagonal shape. The molecules were characterized by scanning tunneling microscopy and density functional theory (DFT) calculations. On the Ag(111) surface, the macrocycles act as molecular quantum corrals and lead to the confinement of surface-state electrons inside the central cavity. The energy of the confined surface state correlates with the size of the macrocycle and is well described by a particle-in-the-box model. Tunneling spectroscopy suggests conjugation within the planar rings and reveals influences of self-assembly on the electronic structure. While the adsorbed molecules appear to be approximately planar, the free molecules have nonplanar conformation, according to DFT.

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...

Quantitative roughness characterization and 3D reconstruction of electrode surface using cyclic voltammetry and SEM image

Energy Technology Data Exchange (ETDEWEB)

Dhillon, Shweta; Kant, Rama, E-mail: rkant@chemistry.du.ac.in

2013-10-01

Area measurements from cyclic voltammetry (CV) and image from scanning electron microscopy (SEM) are used to characterize electrode statistical morphology, 3D surface reconstruction and its electroactivity. SEM images of single phased materials correspond to two-dimensional (2D) projections of 3D structures, leading to an incomplete characterization. Lack of third dimension information in SEM image is circumvented using equivalence between denoised SEM image and CV area measurements. This CV-SEM method can be used to estimate power spectral density (PSD), width, gradient, finite fractal nature of roughness and local morphology of the electrode. We show that the surface morphological statistical property like distribution function of gradient can be related to local electro-activity. Electrode surface gradient micrographs generated here can provide map of electro-activity sites. Finally, the densely and uniformly packed small gradient over the Pt-surface is the determining criterion for high intrinsic electrode activity.

Quantitative roughness characterization and 3D reconstruction of electrode surface using cyclic voltammetry and SEM image

International Nuclear Information System (INIS)

Dhillon, Shweta; Kant, Rama

2013-01-01

Area measurements from cyclic voltammetry (CV) and image from scanning electron microscopy (SEM) are used to characterize electrode statistical morphology, 3D surface reconstruction and its electroactivity. SEM images of single phased materials correspond to two-dimensional (2D) projections of 3D structures, leading to an incomplete characterization. Lack of third dimension information in SEM image is circumvented using equivalence between denoised SEM image and CV area measurements. This CV-SEM method can be used to estimate power spectral density (PSD), width, gradient, finite fractal nature of roughness and local morphology of the electrode. We show that the surface morphological statistical property like distribution function of gradient can be related to local electro-activity. Electrode surface gradient micrographs generated here can provide map of electro-activity sites. Finally, the densely and uniformly packed small gradient over the Pt-surface is the determining criterion for high intrinsic electrode activity.

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

Spectral analysis of surface waves method to assess shear wave velocity within centrifuge models

Science.gov (United States)

Murillo, Carol Andrea; Thorel, Luc; Caicedo, Bernardo

2009-06-01

The method of the spectral analysis of surface waves (SASW) is tested out on reduced scale centrifuge models, with a specific device, called the mini Falling Weight, developed for this purpose. Tests are performed on layered materials made of a mixture of sand and clay. The shear wave velocity VS determined within the models using the SASW is compared with the laboratory measurements carried out using the bender element test. The results show that the SASW technique applied to centrifuge testing is a relevant method to characterize VS near the surface.

Surface roughness characterization of cast components using 3D optical methods

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat; Hansen, Hans Nørgaard

scanning probe image processor (SPIP) software and the results of the surface roughness parameters obtained were subjected to statistical analyses. The bearing area ratio was introduced and applied to the surface roughness analysis. From the results, the surface quality of the standard comparators...... is successfully characterised and it was established that the areal parameters are more informative for sand cast components. The roughness values of the standard visual comparators can serve as a control for the cast components and for order specifications in the foundry industry. A series of iron castings were...... made in green sand moulds and the surface roughness parameter (Sa) values were compared with those of the standards. Sa parameter suffices for the evaluation of casting surface texture. The S series comparators showed a better description of the surface of castings after shot blasting than the A series...

Characterization of complementary electric field coupled resonant surfaces

Science.gov (United States)

Hand, Thomas H.; Gollub, Jonah; Sajuyigbe, Soji; Smith, David R.; Cummer, Steven A.

2008-11-01

We present angle-resolved free-space transmission and reflection measurements of a surface composed of complementary electric inductive-capacitive (CELC) resonators. By measuring the reflection and transmission coefficients of a CELC surface with different polarizations and particle orientations, we show that the CELC only responds to in-plane magnetic fields. This confirms the Babinet particle duality between the CELC and its complement, the electric field coupled LC resonator. Characterization of the CELC structure serves to expand the current library of resonant elements metamaterial designers can draw upon to make unique materials and surfaces.

Sliding surface searching method for slopes containing a potential weak structural surface

Directory of Open Access Journals (Sweden)

Aijun Yao

2014-06-01

Full Text Available Weak structural surface is one of the key factors controlling the stability of slopes. The stability of rock slopes is in general concerned with set of discontinuities. However, in soft rocks, failure can occur along surfaces approaching to a circular failure surface. To better understand the position of potential sliding surface, a new method called simplex-finite stochastic tracking method is proposed. This method basically divides sliding surface into two parts: one is described by smooth curve obtained by random searching, the other one is polyline formed by the weak structural surface. Single or multiple sliding surfaces can be considered, and consequently several types of combined sliding surfaces can be simulated. The paper will adopt the arc-polyline to simulate potential sliding surface and analyze the searching process of sliding surface. Accordingly, software for slope stability analysis using this method was developed and applied in real cases. The results show that, using simplex-finite stochastic tracking method, it is possible to locate the position of a potential sliding surface in the slope.

Surface characterization of silver and palladium modified glassy ...

Indian Academy of Sciences (India)

WINTEC

The morphology of metal coatings was characterized by ... face of sample containing the highest quantity of surface oxide complexes. It has been concluded that ..... Environment Protection of the Republic of Serbia for financial support.

Characterization methods

Energy Technology Data Exchange (ETDEWEB)

Glass, J.T. [North Carolina State Univ., Raleigh (United States)

1993-01-01

Methods discussed in this compilation of notes and diagrams are Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, and other surface analysis techniques (auger electron spectroscopy, x-ray photoelectron spectroscopy, electron energy loss spectroscopy, and scanning tunnelling microscopy). A comparative evaluation of different techniques is performed. In-vacuo and in-situ analyses are described.

Micro- and nanoscale characterization of hydrophobic and hydrophilic leaf surfaces

International Nuclear Information System (INIS)

Bhushan, Bharat; Jung, Yong Chae

2006-01-01

Superhydrophobic surfaces as well as low adhesion and friction are desirable for various industrial applications. Certain plant leaves are known to be hydrophobic in nature due to their roughness and the presence of a thin wax film on the surface of the leaf. The purpose of this study is to fully characterize the leaf surfaces on the micro- and nanoscale while separating out the effects of the micro- and the nanobumps of hydrophobic leaves on the hydrophobicity. Hydrophilic leaves were also studied to better understand the role of wax and roughness. Furthermore, the adhesion and friction properties of hydrophobic and hydrophilic leaves were studied. Using an optical profiler and an atomic/friction force microscope (AFM/FFM), measurements were made to fully characterize the leaf surfaces. It is shown that the nanobumps play a more important role than the microbumps in the hydrophobic nature as well as friction of the leaf. This study will be useful in developing superhydrophobic surfaces

SEM, Scanning Auger and XPS characterization of chemically pretreated Ti surfaces intended for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Pisarek, M. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland); Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland)], E-mail: marcinp@ichf.edu.pl; Lewandowska, M. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland); Roguska, A. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland); Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland); Kurzydlowski, K.J. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland); Janik-Czachor, M. [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland)

2007-07-15

Titanium is known as a biocompatible metal characterized by biological and corrosion immunity and good mechanical properties, including a high fracture toughness. In a variety of environments, this metal undergoes 'natural' oxidation which determine its resistance to corrosion. It can also be exposed to chemical treatments in acidic or alkaline solutions which 'enforces' chemical and morphological changes of Ti surface. Those methods, if well controlled, may increase the effective Ti surface area, making it more biocompatible. However, the morphological and chemical factors responsible for their interactions with biological cells are still not well known. The aim of this work was to compare surface chemical and morphological changes introduced by commonly used aqueous NaOH pretreatment with those occurring in a new 'piranha' acidic solution. Particular attention was paid to possible changes which may be decisive for the biocompatibility of the Ti-elements subjected to these surface modifications. Surface analytical techniques such as Auger electron spectroscopy (AES) or X-ray photoelectron spectroscopy (XPS) combined with Ar{sup +} ion sputtering allowed us to investigate in detail the chemical composition of Ti oxide layers. SEM examinations provided morphological characterization of the surface of Ti samples. The results revealed large difference in morphology of Ti surfaces pretreated with different procedures whereas only minor difference in the chemistry of the surfaces were detected.

Characterisation of surface roughness for ultra-precision freeform surfaces

International Nuclear Information System (INIS)

Li Huifen; Cheung, C F; Lee, W B; To, S; Jiang, X Q

2005-01-01

Ultra-precision freeform surfaces are widely used in many advanced optics applications which demand for having surface roughness down to nanometer range. Although a lot of research work has been reported on the study of surface generation, reconstruction and surface characterization such as MOTIF and fractal analysis, most of them are focused on axial symmetric surfaces such as aspheric surfaces. Relative little research work has been found in the characterization of surface roughness in ultra-precision freeform surfaces. In this paper, a novel Robust Gaussian Filtering (RGF) method is proposed for the characterisation of surface roughness for ultra-precision freeform surfaces with known mathematic model or a cloud of discrete points. A series of computer simulation and measurement experiments were conducted to verify the capability of the proposed method. The experimental results were found to agree well with the theoretical results

Analysis of fracture surface of CFRP material by three-dimensional reconstruction methods

International Nuclear Information System (INIS)

Lobo, Raquel M.; Andrade, Arnaldo H.P.

2009-01-01

Fracture surfaces of CFRP (carbon Fiber Reinforced Polymer) materials, used in the nuclear fuel cycle, presents an elevated roughness, mainly due to the fracture mode known as pulling out, that displays pieces of carbon fibers after debonding between fiber and matrix. The fractographic analysis, by bi-dimensional images is deficient for not considering the so important vertical resolution as much as the horizontal resolution. In this case, the knowledge of this heights distribution that occurs during the breaking, can lead to the calculation of the involved energies in the process that would allows a better agreement on the fracture mechanisms of the composite material. An important solution for the material characterization, whose surface presents a high roughness due to the variation in height, is to reconstruct three-dimensionally these fracture surfaces. In this work, the 3D reconstruction was done by two different methods: the variable focus reconstruction, through a stack of images obtained by optical microscopy (OM) and the parallax reconstruction, carried through with images acquired by scanning electron microscopy (SEM). The results of both methods present an elevation map of the reconstructed image that determine the height of the surface pixel by pixel,. The results obtained by the methods of reconstruction for the CFRP surfaces, have been compared with others materials such as aluminum and copper that present a ductile type fracture surface, with lower roughness. (author)

Thiolated poly(ɛ-caprolactone) macroligand with vacant coordination sites on gold substrate: Synthesis and surface characterization

Science.gov (United States)

Farah, Abdiaziz A.; Zheng, Susan H.; Morin, Sylvie; Bensebaa, Farid; Pietro, William J.

2007-04-01

Surface-confined telechelic poly(ɛ-caprolactone) macroligand with two distinct functional groups per polymeric chain has been synthesized and characterized. The molecular microstructure of the macroligand with regard to the properties of the end-capped functionalities and with those on surface substrate has been studied by solution and surface analytical methods (i.e., X-ray photoelectron spectroscopy (XPS), grazing angle reflectance-Fourier transform IR spectroscopy (GA-FTIR), water contact angle measurements, and atomic force microscopy (AFM)) to elucidate the structure and properties of such multifunctional polymer on gold (1 1 1) substrate.

Surface functionalization of cyclic olefin copolymer with aryldiazonium salts: A covalent grafting method

International Nuclear Information System (INIS)

Brisset, Florian; Vieillard, Julien; Berton, Benjamin; Morin-Grognet, Sandrine; Duclairoir-Poc, Cécile; Le Derf, Franck

2015-01-01

Graphical abstract: - Highlights: • An effective method to modify cyclic olefin copolymer surface. • The surface of COC was modified by covalent grafting of aryl diazonium salts. • The wettability of COC surface was modulated by diazonium salts. • Photoinitiation and chemical reduction have to be combined to graft diazonium salt on COC surface. - Abstract: Covalent immobilization of biomolecules on the surface of cyclic olefin copolymer (COC) is still a tough challenge. We developed a robust method for COC surface grafting through reaction with aryldiazonium. Chemical diazonium reduction generated an aryl radical and the formation of a grafted film layer on the organic surface. We also demonstrated that the chemical reduction of diazonium salt was not sufficient to form a film on the COC surface. UV illumination had to be combined with chemical reduction to graft an aryl layer onto the COC surface. We optimized organic film deposition by using different chemical reducers, different reaction times and reagent proportions. We characterized surface modifications by fluorescence microscopy and contact angle measurements, infrared spectroscopy, X-ray photoemission spectroscopy and Raman spectroscopy, and assessed the topography of the aryl film by atomic force microscopy. This original strategy allowed us to evidence various organic functions to graft biomolecules onto COC surfaces with a fast and efficient technique

Surface functionalization of cyclic olefin copolymer with aryldiazonium salts: A covalent grafting method

Energy Technology Data Exchange (ETDEWEB)

Brisset, Florian, E-mail: florian.brisset@etu.univ-rouen.fr [UMR CNRS 6014 COBRA, FR 3038, Université de Rouen, 55 rue Saint Germain, 27000 Evreux (France); Vieillard, Julien, E-mail: julien.vieillard@univ-rouen.fr [UMR CNRS 6014 COBRA, FR 3038, Université de Rouen, 55 rue Saint Germain, 27000 Evreux (France); Berton, Benjamin, E-mail: benjamin.berton@univ-rouen.fr [EA 3233 SMS, Université de Rouen, 1 rue du 7ème Chasseurs, BP281, 27002 Evreux Cedex (France); Morin-Grognet, Sandrine, E-mail: sandrine.morin@univ-rouen.fr [EA 3829 MERCI, Université de Rouen, 1 rue du 7ème Chasseurs, BP281, 27002 Evreux Cedex (France); Duclairoir-Poc, Cécile, E-mail: cecile.duclairoir@univ-rouen.fr [EA 4312 LMSM, Université de Rouen, 55 rue Saint Germain, 27000 Evreux (France); Le Derf, Franck, E-mail: franck.lederf@univ-rouen.fr [UMR CNRS 6014 COBRA, FR 3038, Université de Rouen, 55 rue Saint Germain, 27000 Evreux (France)

2015-02-28

Graphical abstract: - Highlights: • An effective method to modify cyclic olefin copolymer surface. • The surface of COC was modified by covalent grafting of aryl diazonium salts. • The wettability of COC surface was modulated by diazonium salts. • Photoinitiation and chemical reduction have to be combined to graft diazonium salt on COC surface. - Abstract: Covalent immobilization of biomolecules on the surface of cyclic olefin copolymer (COC) is still a tough challenge. We developed a robust method for COC surface grafting through reaction with aryldiazonium. Chemical diazonium reduction generated an aryl radical and the formation of a grafted film layer on the organic surface. We also demonstrated that the chemical reduction of diazonium salt was not sufficient to form a film on the COC surface. UV illumination had to be combined with chemical reduction to graft an aryl layer onto the COC surface. We optimized organic film deposition by using different chemical reducers, different reaction times and reagent proportions. We characterized surface modifications by fluorescence microscopy and contact angle measurements, infrared spectroscopy, X-ray photoemission spectroscopy and Raman spectroscopy, and assessed the topography of the aryl film by atomic force microscopy. This original strategy allowed us to evidence various organic functions to graft biomolecules onto COC surfaces with a fast and efficient technique.

Characterization of the damage produced on different materials surfaces

International Nuclear Information System (INIS)

Dellavale Clara, Hector Damian

2004-01-01

In the present work the characterization techniques of surfaces ULOI and RIMAPS have been applied on laboratory samples made from aluminium, stainless steel and material based on fiberglass.The resultant surfaces of, chemical etching with corrosive agents Keller and Tucker, mechanic damage from the wear and tear of abrasive paper and sandrubbing with alumina particles, are analyzed to different level of damage.The systematic application of the above mentioned techniques is carried out with the objective of finding information, which allows to characterize the superficial damage, both in its incipient state as in the extreme situation revealed by the presence of etch pits. Important results have been obtained, in the characterization of the incipient stage of the chemical etching, using the curves of the normalized area.In addition, it was possible to verify the capacity of the techniques in the early detection of the preferential directions generated by the etch pits

Fabrication of metallic surfaces with long-term superhydrophilic property using one-stop laser method

International Nuclear Information System (INIS)

Guan, Y.C.; Luo, F.F.; Lim, G.C.; Hong, M.H.; Zheng, H.Y.; Qi, Bojin

2015-01-01

Highlights: • One-stop laser method is presented to fabricate superhydrophilic surface on metals. • Wettability study shows the longest superhydrophilic duration as more than 1 month. • Water-soluble compounds, polar functional groups and dual-scale structures were formed. • Surface roughness shows an amplification effect of the wetting behavior. - Abstract: A simple method for fabricating stable superhydrophilic surface at metallic substrates is reported. This technique comprises irradiating the surface with multiple laser pulses. Surface wettability can be taylored through controlling laser parameters and processing conditions. The substrates were selected as aluminum alloy and stainless steel. Physical morphology and chemical composition of laser-textured surfaces were characterized by SEM, XPS, and 3D profiler measurements. Results showed that the longest wettability duration was achieved as more than 1 month for stainless steel and more than 200 h for Al alloy, respectively. The possible mechanism of hydrophilic behavior of laser-textured surfaces was discussed. The effect of surface topography on superhydrophilicity property was also evaluated. This study presents a promising method in fabricating long-term superhydrophilic surfaces, which is useful for improving adhesion or achieving water-assisted flow in industrial applications as well as developing cell-based technologies in biomedical applications

The surface analysis methods

International Nuclear Information System (INIS)

Deville, J.P.

1998-01-01

Nowadays, there are a lot of surfaces analysis methods, each having its specificity, its qualities, its constraints (for instance vacuum) and its limits. Expensive in time and in investment, these methods have to be used deliberately. This article appeals to non specialists. It gives some elements of choice according to the studied information, the sensitivity, the use constraints or the answer to a precise question. After having recalled the fundamental principles which govern these analysis methods, based on the interaction between radiations (ultraviolet, X) or particles (ions, electrons) with matter, two methods will be more particularly described: the Auger electron spectroscopy (AES) and x-rays photoemission spectroscopy (ESCA or XPS). Indeed, they are the most widespread methods in laboratories, the easier for use and probably the most productive for the analysis of surface of industrial materials or samples submitted to treatments in aggressive media. (O.M.)

Surface topography characterization using 3D stereoscopic reconstruction of SEM images

Science.gov (United States)

Vedantha Krishna, Amogh; Flys, Olena; Reddy, Vijeth V.; Rosén, B. G.

2018-06-01

A major drawback of the optical microscope is its limitation to resolve finer details. Many microscopes have been developed to overcome the limitations set by the diffraction of visible light. The scanning electron microscope (SEM) is one such alternative: it uses electrons for imaging, which have much smaller wavelength than photons. As a result high magnification with superior image resolution can be achieved. However, SEM generates 2D images which provide limited data for surface measurements and analysis. Often many research areas require the knowledge of 3D structures as they contribute to a comprehensive understanding of microstructure by allowing effective measurements and qualitative visualization of the samples under study. For this reason, stereo photogrammetry technique is employed to convert SEM images into 3D measurable data. This paper aims to utilize a stereoscopic reconstruction technique as a reliable method for characterization of surface topography. Reconstructed results from SEM images are compared with coherence scanning interferometer (CSI) results obtained by measuring a roughness reference standard sample. This paper presents a method to select the most robust/consistent surface texture parameters that are insensitive to the uncertainties involved in the reconstruction technique itself. Results from the two-stereoscopic reconstruction algorithms are also documented in this paper.

Characterization methods of nuclear fuel materials

International Nuclear Information System (INIS)

Bustillos, O.W.R.; Teixeira, S.R.; Lordello, A.R.; Imakuma, K.; Rodrigues, C.

1980-01-01

In order to organize quality control and quality assurance activities for PWR fuel production, the laboratory of IPEN (Instituto de Pesquisas Energeticas e Nucleares) has developed various chemical and physical methods to be employed for fuel characterization of UO 2 pellets. The techniques developed are the determination of total residual gases by vacuum fusion method, determination of impurity elements by optical spectrography and characterization methods by X-ray diffraction. The development and the implementation of these techniques under the implementation of these techniques under the general scheme of characterization and quality control is the major theme discussed. (E.G.) [pt

Surface Characterization of Nanoparticles: Critical Needs and Significant Challenges

International Nuclear Information System (INIS)

Baer, Donald R.

2011-01-01

There is a growing recognition that nanoparticles and other nanostructured materials are sometimes inadequately characterized and that this may limit or even invalidate some of the conclusions regarding particle properties and behavior. A number of international organizations are working to establish the essential measurement requirements that enable adequate understanding of nanoparticle properties for both technological applications and for environmental health issues. Our research on the interaction of iron metal-core oxide-shell nanoparticles with environmental contaminants and studies of the behaviors of ceria nanoparticles, with a variety of medical, catalysis and energy applications, have highlighted a number of common nanoparticle characterization challenges that have not been fully recognized by parts of the research community. This short review outlines some of these characterization challenges based on our research observations and using other results reported in the literature. Issues highlighted include: (1) the importance of surfaces and surface characterization, (2) nanoparticles are often not created equal - subtle differences in synthesis and processing can have large impacts; (3) nanoparticles frequently change with time having lifetime implications for products and complicating understanding of health and safety impacts; (4) the high sensitivity of nanoparticles to their environment complicates characterization and applications in many ways; (5) nanoparticles are highly unstable and easily altered (damaged) during analysis.

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.

The Chameleon Effect: characterization challenges due to the variability of nanoparticles and their surfaces

Energy Technology Data Exchange (ETDEWEB)

Baer, Donald R.

2018-05-07

Nanoparticles in a variety of forms are of increasing importance in fundamental research, technological and medical applications, and environmental or toxicology studies. Physical and chemical drivers that lead to multiple types of particle instabilities complicate both the ability to produce and consistently deliver well defined particles and their appropriate characterization, frequently leading to inconsistencies and conflicts in the published literature. This perspective suggests that provenance information, beyond that often recorded or reported, and application of a set of core characterization methods, including a surface sensitive technique, consistently applied at critical times can serve as tools in the effort minimize reproducibility issues.

The Chameleon Effect: Characterization Challenges Due to the Variability of Nanoparticles and Their Surfaces

Directory of Open Access Journals (Sweden)

Donald R. Baer

2018-05-01

Full Text Available Nanoparticles in a variety of forms are increasing important in fundamental research, technological and medical applications, and environmental or toxicology studies. Physical and chemical drivers that lead to multiple types of particle instabilities complicate both the ability to produce, appropriately characterize, and consistently deliver well-defined particles, frequently leading to inconsistencies, and conflicts in the published literature. This perspective suggests that provenance information, beyond that often recorded or reported, and application of a set of core characterization methods, including a surface sensitive technique, consistently applied at critical times can serve as tools in the effort minimize reproducibility issues.

Characterization of surface properties of glass vials used as primary packaging material for parenterals.

Science.gov (United States)

Ditter, Dominique; Mahler, Hanns-Christian; Roehl, Holger; Wahl, Michael; Huwyler, Joerg; Nieto, Alejandra; Allmendinger, Andrea

2018-04-01

different vial types may serve as basis to further guide the selection of adequate primary packaging based on the desired quality target product profile and to support studies of glass surface interactions with formulations. The proposed analytical method panel can be used for characterization of future glass vials either before delivery to the manufacturer or drug product manufacturing. Copyright © 2018 Elsevier B.V. All rights reserved.

Surface characterization of pretreated and microbial-treated populus cross-sections

Energy Technology Data Exchange (ETDEWEB)

Tolbert, Allison K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-05-01

The first objective of this thesis is to illustrate the advantages of surface characterization in biomass utilization studies. The second objective is to gain insight into the workings of potential consolidated bioprocessing microorganisms on the surface of poplar samples. The third objective is to determine the impact biomass recalcitrance has on enzymatic hydrolysis and microbial fermentation in relation to the surface chemistry.

RELIABILITY AND ACCURACY ASSESSMENT OF INVASIVE AND NON- INVASIVE SEISMIC METHODS FOR SITE CHARACTERIZATION: FEEDBACK FROM THE INTERPACIFIC PROJECT

OpenAIRE

Garofalo , F.; Foti , S.; Hollender , F.; Bard , P.-Y.; Cornou , C.; Cox , B.R.; Dechamp , A.; Ohrnberger , M.; Sicilia , D.; Vergniault , C.

2017-01-01

International audience; The InterPacific project (Intercomparison of methods for site parameter and velocity profile characterization) aims to assess the reliability of seismic site characterization methods (borehole and surface wave methods) used for estimating shear wave velocity (VS) profiles and other related parameters (e.g., VS30). Three sites, representative of different geological conditions relevant for the evaluation of seismic site response effects, have been selected: (1) a hard r...

Multiscale analysis of replication technique efficiency for 3D roughness characterization of manufactured surfaces

Science.gov (United States)

Jolivet, S.; Mezghani, S.; El Mansori, M.

2016-09-01

The replication of topography has been generally restricted to optimizing material processing technologies in terms of statistical and single-scale features such as roughness. By contrast, manufactured surface topography is highly complex, irregular, and multiscale. In this work, we have demonstrated the use of multiscale analysis on replicates of surface finish to assess the precise control of the finished replica. Five commercial resins used for surface replication were compared. The topography of five standard surfaces representative of common finishing processes were acquired both directly and by a replication technique. Then, they were characterized using the ISO 25178 standard and multiscale decomposition based on a continuous wavelet transform, to compare the roughness transfer quality at different scales. Additionally, atomic force microscope force modulation mode was used in order to compare the resins’ stiffness properties. The results showed that less stiff resins are able to replicate the surface finish along a larger wavelength band. The method was then tested for non-destructive quality control of automotive gear tooth surfaces.

Radioactive Ions for Surface Characterization

CERN Multimedia

2002-01-01

The collaboration has completed a set of pilot experiments with the aim to develop techniques for using radioactive nuclei in surface physics. The first result was a method for thermal deposition of isolated atoms (Cd, In, Rb) on clean metallic surfaces. \\\\ \\\\ Then the diffusion history of deposited Cd and In atoms on two model surfaces, Mo(110) and Pd(111), was followed through the electric field gradients (efg) acting at the probe nuclei as measured with the Perturbed Angular Correlation technique. For Mo(110) a rather simple history of the adatoms was inferred from the experiments: Atoms initially landing at terrace sites diffuse from there to ledges and then to kinks, defects always present at real surfaces. The next stage is desorption from the surface. For Pd a scenario that goes still further was found. Following the kink stage the adatoms get incorporated into ledges and finally into the top surface layer. For all these five sites the efg's could be measured.\\\\ \\\\ In preparation for a further series o...

Characterizing lentic freshwater fish assemblages using multiple sampling methods

Science.gov (United States)

Fischer, Jesse R.; Quist, Michael C.

2014-01-01

Characterizing fish assemblages in lentic ecosystems is difficult, and multiple sampling methods are almost always necessary to gain reliable estimates of indices such as species richness. However, most research focused on lentic fish sampling methodology has targeted recreationally important species, and little to no information is available regarding the influence of multiple methods and timing (i.e., temporal variation) on characterizing entire fish assemblages. Therefore, six lakes and impoundments (48–1,557 ha surface area) were sampled seasonally with seven gear types to evaluate the combined influence of sampling methods and timing on the number of species and individuals sampled. Probabilities of detection for species indicated strong selectivities and seasonal trends that provide guidance on optimal seasons to use gears when targeting multiple species. The evaluation of species richness and number of individuals sampled using multiple gear combinations demonstrated that appreciable benefits over relatively few gears (e.g., to four) used in optimal seasons were not present. Specifically, over 90 % of the species encountered with all gear types and season combinations (N = 19) from six lakes and reservoirs were sampled with nighttime boat electrofishing in the fall and benthic trawling, modified-fyke, and mini-fyke netting during the summer. Our results indicated that the characterization of lentic fish assemblages was highly influenced by the selection of sampling gears and seasons, but did not appear to be influenced by waterbody type (i.e., natural lake, impoundment). The standardization of data collected with multiple methods and seasons to account for bias is imperative to monitoring of lentic ecosystems and will provide researchers with increased reliability in their interpretations and decisions made using information on lentic fish assemblages.

Functional properties of bio-inspired surfaces: characterization and technological applications

National Research Council Canada - National Science Library

Favret, Eduardo A; Fuentes, Néstor O

2009-01-01

... technological materials. It analyses how such surfaces can be described and characterized using microscopic techniques and thus reproduced, encompassing the important areas of current surface replication techniques and the associated acquisition of good master structures. It is well known that biological systems have the ability to sense, ...

The Mobile Surface Contamination Monitor II environmental radiological characterization utilizing GPS/GIS technologies

International Nuclear Information System (INIS)

Wendling, M.A.

1993-05-01

Time, cost, and most importantly quality of data are the three factors to measure the success of field radiological characterizations. The application of coupling radiation detection instrumentation to a GPS receiver has dramatically increased the data quality achievable compared to traditional environmental radiological survey methods. Improvements in verifying adequate spatial coverage of an area while collecting data and at,the same time reducing field time requirements can be realized. Data acquired during the recent implementation of the Mobile Surface Contamination Monitor 11 (MSCM-11) will be presented to demonstrate the advantages of this system over traditional radiological survey methods. The comparison will include time and manpower requirements. Linking the complimentary GPS, GIS and radiation detection technologies on a mobile tractor based platform has provided a tool to provide radiological characterization data faster, cheaper, and better to assist in the Environmental Restoration Mission of the Hanford Site

Anisotropic characterization of rock fracture surfaces subjected to profile analysis

International Nuclear Information System (INIS)

Zhou, H.W.; Xie, H.

2004-01-01

The mechanical parameters of a rock fracture are dependent on its surface roughness anisotropy. In this Letter, we show how quantitatively describe the anisotropy of a rock fracture surface. A parameter, referred to as the index for the accumulation power spectral density psd*, is proposed to characterize the anisotropy of a rock fracture surface. Variation of psd*, with orientation angle θ of sampling, is also discussed

Characterization of the rock joint surface. A contribution to DECOVALEX II Task 3 'Constitutive relationships of rock joints'

International Nuclear Information System (INIS)

Vuopio, J.; Poellae, J.

1997-12-01

In order to understand the effects of spent fuel on the hydraulical behaviour of the rock mass it is necessary to have knowledge about the relationship between the stresses and hydraulical properties of the fractures. The roughness of a fracture surface governs the dilatation of the fracture and the displacement of the fracture surface under shear stress. The peak shear strength and hydraulic flow properties of fractures depend very much on the surface roughness. This report describes different methods and techniques used in the characterization of rock joint surfaces and their applications in rock mechanics

Optical method for the characterization of laterally patterned samples in integrated circuits

Science.gov (United States)

Maris, Humphrey J [Barrington, RI

2009-03-17

Disclosed is a method for characterizing a sample having a structure disposed on or within the sample, comprising the steps of applying a first pulse of light to a surface of the sample for creating a propagating strain pulse in the sample, applying a second pulse of light to the surface so that the second pulse of light interacts with the propagating strain pulse in the sample, sensing from a reflection of the second pulse a change in optical response of the sample, and relating a time of occurrence of the change in optical response to at least one dimension of the structure.

A Modified Water-Table Fluctuation Method to Characterize Regional Groundwater Discharge

Directory of Open Access Journals (Sweden)

Lihong Yang

2018-04-01

Full Text Available A modified Water-Table Fluctuation (WTF method is developed to quantitatively characterize the regional groundwater discharge patterns in stressed aquifers caused by intensive agricultural pumping. Two new parameters are defined to express the secondary information in the observed data. One is infiltration efficiency and the other is discharge modulus (recurring head loss due to aquifer discharge. An optimization procedure is involved to estimate these parameters, based on continuous groundwater head measurements and precipitation records. Using the defined parameters and precipitation time series, water level changes are calculated for individual wells with fidelity. The estimated parameters are then used to further address the characterization of infiltration and to better quantify the discharge at the regional scale. The advantage of this method is that it considers recharge and discharge simultaneously, whereas the general WTF methods mostly focus on recharge. In the case study, the infiltration efficiency reveals that the infiltration is regionally controlled by the intrinsic characteristics of the aquifer, and locally distorted by engineered hydraulic structures that alter surface water-groundwater interactions. The seasonality of groundwater discharge is characterized by the monthly discharge modulus. These results from individual wells are clustered into groups that are consistent with the local land use pattern and cropping structures.

High-throughput characterization methods for lithium batteries

Directory of Open Access Journals (Sweden)

Yingchun Lyu

2017-09-01

Full Text Available The development of high-performance lithium ion batteries requires the discovery of new materials and the optimization of key components. By contrast with traditional one-by-one method, high-throughput method can synthesize and characterize a large number of compositionally varying samples, which is able to accelerate the pace of discovery, development and optimization process of materials. Because of rapid progress in thin film and automatic control technologies, thousands of compounds with different compositions could be synthesized rapidly right now, even in a single experiment. However, the lack of rapid or combinatorial characterization technologies to match with high-throughput synthesis methods, limit the application of high-throughput technology. Here, we review a series of representative high-throughput characterization methods used in lithium batteries, including high-throughput structural and electrochemical characterization methods and rapid measuring technologies based on synchrotron light sources.

Surface characterization of self-assembled N-Cu nanostructures

Energy Technology Data Exchange (ETDEWEB)

Cristina, Lucila J.; Moreno-Lopez, Juan C. [Laboratorio de Superficies e Interfaces, Instituto de Desarrollo Tecnologico para la Industria Quimica (CONICET-UNL), Gueemes 3450, (S3000GLN) Santa Fe (Argentina); Sferco, Silvano J. [Laboratorio de Superficies e Interfaces, Instituto de Desarrollo Tecnologico para la Industria Quimica (CONICET-UNL), Gueemes 3450, (S3000GLN) Santa Fe (Argentina); Departamento de Fisica, Facultad de Bioquimica y Ciencias Biologicas, Universidad Nacional del Litoral, Ciudad Universitaria, C.C. 242, (S3000ZAA) Santa Fe (Argentina); Passeggi, Mario C.G.; Vidal, Ricardo A. [Laboratorio de Superficies e Interfaces, Instituto de Desarrollo Tecnologico para la Industria Quimica (CONICET-UNL), Gueemes 3450, (S3000GLN) Santa Fe (Argentina); Ferron, Julio, E-mail: jferron@intec.unl.edu.ar [Laboratorio de Superficies e Interfaces, Instituto de Desarrollo Tecnologico para la Industria Quimica (CONICET-UNL), Gueemes 3450, (S3000GLN) Santa Fe (Argentina); Departamento de Materiales, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2829,(S3000AOM) Santa Fe (Argentina)

2012-01-01

We report on the process of low energy N{sub 2}{sup +} implantation and annealing of a Cu(0 0 1) surface. Through AES we study the N diffusion process as a function of the substrate temperature. With STM and LEIS we characterize the surface morphology and the electronic structure is analyzed with ARUPS. Under annealing (500 < T < 700 K) N migrates to the surface and reacts forming a Cu{sub x}N compound that decomposes at temperatures above 700 K. LEIS measurements show that N locates on the four-fold hollow sites of the Cu(0 0 1) surface in a c(2 Multiplication-Sign 2) arrangement. Finally, a gap along the [0 0 1] azimuthal direction is determined by ARUPS. DFT calculations provide support to our conclusions.

Multi-scale characterization of surface blistering morphology of helium irradiated W thin films

International Nuclear Information System (INIS)

Yang, J.J.; Zhu, H.L.; Wan, Q.; Peng, M.J.; Ran, G.; Tang, J.; Yang, Y.Y.; Liao, J.L.; Liu, N.

2015-01-01

Highlights: • Multi-scale blistering morphology of He irradiated W film was studied. • This complex morphology was first characterized by wavelet transform approach. - Abstract: Surface blistering morphologies of W thin films irradiated by 30 keV He ion beam were studied quantitatively. It was found that the blistering morphology strongly depends on He fluence. For lower He fluence, the accumulation and growth of He bubbles induce the intrinsic surface blisters with mono-modal size distribution feature. When the He fluence is higher, the film surface morphology exhibits a multi-scale property, including two kinds of surface blisters with different characteristic sizes. In addition to the intrinsic He blisters, film/substrate interface delamination also induces large-sized surface blisters. A strategy based on wavelet transform approach was proposed to distinguish and extract the multi-scale surface blistering morphologies. Then the density, the lateral size and the height of these different blisters were estimated quantitatively, and the effect of He fluence on these geometrical parameters was investigated. Our method could provide a potential tool to describe the irradiation induced surface damage morphology with a multi-scale property

Statistical characterization of surface features from tungsten-coated divertor inserts in the DIII-D Metal Rings Campaign

Science.gov (United States)

Adams, Jacob; Unterberg, Ezekial; Chrobak, Christopher; Stahl, Brian; Abrams, Tyler

2017-10-01

Continuing analysis of tungsten-coated inserts from the recent DIII-D Metal Rings Campaign utilizes a statistical approach to study carbon migration and deposition on W surfaces and to characterize the pre- versus post-exposure surface morphology. A TZM base was coated with W using both CVD and PVD and allowed for comparison between the two coating methods. The W inserts were positioned in the lower DIII-D divertor in both the upper (shelf) region and lower (floor) region and subjected to multiple plasma shots, primarily in H-mode. Currently, the post-exposure W inserts are being characterized using SEM/EDX to qualify the surface morphology and to quantify the surface chemical composition. In addition, profilometry is being used to measure the surface roughness of the inserts both before and after plasma exposure. Preliminary results suggest a correlation between the pre-exposure surface roughness and the level of carbon deposited on the surface. Furthermore, ongoing in-depth analysis may reveal insights into the formation mechanism of nanoscale bumps found in the carbon-rich regions of the W surfaces that have not yet been explained. Work supported in part by US DoE under the Science Undergraduate Laboratory Internship (SULI) program and under DE-FC02-04ER54698.

Optical Characterization of Nanostructured Surfaces

DEFF Research Database (Denmark)

Feidenhans'l, Nikolaj Agentoft

Micro- and nanostructured surfaces are interesting due to the unique properties they add to the bulk material. One example is structural colors, where the interaction between surface structures and visible light produce bright color effects without the use of paints or dyes. Several research groups...... modeling to evaluate the dimensions of subwavelength gratings, by correlating the reflected light measured from the structures with a database of simulations. A new method is developed and termed color scatterometry, since compared to typical spectroscopic scatterometry, which evaluates the full reflection...... spectrum; the new method only evaluates the color of the reflected light using a standard RGB color camera. Color scatterometry provides the combined advantages of spectroscopic scatterometry, which provides fast evaluations, and imaging scatterometry that provides an overview image from which small...

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.

An AFM-based pit-measuring method for indirect measurements of cell-surface membrane vesicles

International Nuclear Information System (INIS)

Zhang, Xiaojun; Chen, Yuan; Chen, Yong

2014-01-01

Highlights: • Air drying induced the transformation of cell-surface membrane vesicles into pits. • An AFM-based pit-measuring method was developed to measure cell-surface vesicles. • Our method detected at least two populations of cell-surface membrane vesicles. - Abstract: Circulating membrane vesicles, which are shed from many cell types, have multiple functions and have been correlated with many diseases. Although circulating membrane vesicles have been extensively characterized, the status of cell-surface membrane vesicles prior to their release is less understood due to the lack of effective measurement methods. Recently, as a powerful, micro- or nano-scale imaging tool, atomic force microscopy (AFM) has been applied in measuring circulating membrane vesicles. However, it seems very difficult for AFM to directly image/identify and measure cell-bound membrane vesicles due to the similarity of surface morphology between membrane vesicles and cell surfaces. Therefore, until now no AFM studies on cell-surface membrane vesicles have been reported. In this study, we found that air drying can induce the transformation of most cell-surface membrane vesicles into pits that are more readily detectable by AFM. Based on this, we developed an AFM-based pit-measuring method and, for the first time, used AFM to indirectly measure cell-surface membrane vesicles on cultured endothelial cells. Using this approach, we observed and quantitatively measured at least two populations of cell-surface membrane vesicles, a nanoscale population (<500 nm in diameter peaking at ∼250 nm) and a microscale population (from 500 nm to ∼2 μm peaking at ∼0.8 μm), whereas confocal microscopy only detected the microscale population. The AFM-based pit-measuring method is potentially useful for studying cell-surface membrane vesicles and for investigating the mechanisms of membrane vesicle formation/release

Pure phase LaFeO3 perovskite with improved surface area synthesized using different routes and its characterization

International Nuclear Information System (INIS)

Gosavi, Priti V.; Biniwale, Rajesh B.

2010-01-01

Three different wet chemistry routes, namely co-precipitation, combustion and sol-gel methods were used to synthesize LaFeO 3 perovskite with improved surface area. The synthesized perovskite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), Brunauer-Emmett-Teller (BET) nitrogen adsorption, ultraviolet diffused reflectance spectroscopy (UVDRS) and Fourier transform infrared (FTIR) spectroscopy techniques. Improved surface area was observed for all three methods as compared to the previously reported values. The perovskite synthesized using sol-gel method yields comparatively pure, crystalline phase of LaFeO 3 and relatively higher surface area of 16.5 m 2 g -1 and porosity. The material synthesized using co-precipitation method yielded other phases in addition to the targeted phase. The morphology of perovskite synthesized using co-precipitation method was uniform agglomerates. Combustion method yields flakes type morphology and that of sol-gel method was open pore type morphology. The selection of method for perovskite synthesis largely depends on the targeted application and the desired properties of perovskites. The results reported in this study are useful for establishing a simple scalable method for preparation of high surface area LaFeO 3 as compared to solid-oxide method. Further, the typical heating cycle followed for calcinations resulted in relatively high surface area in the case of all three methods.

Opto-Acoustic Method for the Characterization of Thin-Film Adhesion

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Sanichiro Yoshida

2016-05-01

Full Text Available The elastic property of the film-substrate interface of thin-film systems is characterized with an opto-acoustic method. The thin-film specimens are oscillated with an acoustic transducer at audible frequencies, and the resultant harmonic response of the film surface is analyzed with optical interferometry. Polystyrene, Ti, Ti-Au and Ti-Pt films coated on the same silicon substrate are tested. For each film material, a pair of specimens is prepared; one is coated on a silicon substrate after the surface is treated with plasma bombardment, and the other is coated on an identical silicon substrate without a treatment. Experiments indicate that both the surface-treated and untreated specimens of all film materials have resonance in the audible frequency range tested. The elastic constant of the interface corresponding to the observed resonance is found to be orders of magnitude lower than that of the film or substrate material. Observations of these resonance-like behaviors and the associated stiffness of the interface are discussed.

Morpho-chemical characterization and surface properties of carcinogenic zeolite fibers

International Nuclear Information System (INIS)

Mattioli, Michele; Giordani, Matteo; Dogan, Meral; Cangiotti, Michela; Avella, Giuseppe; Giorgi, Rodorico; Dogan, A. Umran; Ottaviani, Maria Francesca

2016-01-01

Highlights: • Differently carcinogenic zeolite fibers were investigated combining physico-chemical methods. • For the first time, zeolite fibers were studied by means of the EPR technique using different spin probes. • The structural properties and the adsorption capability are function of different types and distributions of adsorption sites. • The interacting ability of erionite is higher than that of other fibrous zeolites. • The surface interacting properties may be related with the carcinogenicity of the zeolite fibers. - Abstract: Erionite belonging to the zeolite family is a human health-hazard, since it was demonstrated to be carcinogenic. Conversely, offretite family zeolites were suspected carcinogenic. Mineralogical, morphological, chemical, and surface characterizations were performed on two erionites (GF1, MD8) and one offretite (BV12) fibrous samples and, for comparison, one scolecite (SC1) sample. The specific surface area analysis indicated a larger availability of surface sites for the adsorption onto GF1, while SC1 shows the lowest one and the presence of large pores in the poorly fibrous zeolite aggregates. Selected spin probes revealed a high adsorption capacity of GF1 compared to the other zeolites, but the polar/charged interacting sites were well distributed, intercalated by less polar sites (Si–O–Si). MD8 surface is less homogeneous and the polar/charged sites are more interacting and closer to each other compared to GF1. The interacting ability of BV12 surface is much lower than that found for GF1 and MD8 and the probes are trapped in small pores into the fibrous aggregates. In comparison with the other zeolites, the non-carcinogenic SC1 shows a poor interacting ability and a lower surface polarity. These results helped to clarify the chemical properties and the surface interacting ability of these zeolite fibers which may be related to their carcinogenicity.

Laser surface textured titanium alloy (Ti–6Al–4V): Part 1 – Surface characterization

Energy Technology Data Exchange (ETDEWEB)

Pfleging, Wilhelm [Karlsruhe Institute of Technology, IAM-AWP, P.O. Box 3640, 76021 Karlsruhe (Germany); Karlsruhe Nano Micro Facility, H.-von-Helmholtz-Pl. 1, 76344 Egg.-Leopoldshafen (Germany); Kumari, Renu [Department of Metal. and Maters. Eng., I. I. T. Kharagpur, WB 721302 (India); Besser, Heino [Karlsruhe Institute of Technology, IAM-AWP, P.O. Box 3640, 76021 Karlsruhe (Germany); Scharnweber, Tim [Karlsruhe Institute of Technology, IBG-1, P.O. Box 3640, 76021 Karlsruhe (Germany); Majumdar, Jyotsna Dutta, E-mail: jyotsna@metal.iitkgp.ernet.in [Department of Metal. and Maters. Eng., I. I. T. Kharagpur, WB 721302 (India)

2015-11-15

Highlights: • Texturing of Ti–6Al–4V with linear and dimple patterns are developed with ArF laser. • Linear textures have width of 25 μm and are at an interval of 20 μm. • Dimple textures are equi-spaced and have a diameter of 60 μm. • Significant refinement of microstructure in textured zone as compared to substrate. • Increased wettability of the textured surface against simulated body fluid. - Abstract: In the present study, a detailed study of the characterization of laser-surface textured titanium alloy (Ti–6Al–4V) with line and dimple geometry developed by using an ArF excimer laser operating at a wavelength of 193 nm with a pulse length of 5 ns is undertaken. The characterization of the textured surface (both the top surface and cross section) is carried out by scanning electron microscopy, electron back scattered diffraction (EBSD) technique and X-ray diffraction techniques. There is refinement of microstructure along with presence of titanium oxides (rutile, anatase and few Ti{sub 2}O{sub 3} phase) in the textured surface as compared to as-received one. The area fractions of linear texture and dimple texture measured by image analysis software are 45% and 20%, respectively. The wettability is increased after laser texturing. The total surface energy is decreased due to linear (29.6 mN/m) texturing and increased due to dimple (67.6 mN/m) texturing as compared to as-received Ti–6Al–4V (37 mN/m). The effect of polar component is more in influencing the surface energy of textured surface.

Laser surface textured titanium alloy (Ti–6Al–4V): Part 1 – Surface characterization

International Nuclear Information System (INIS)

Pfleging, Wilhelm; Kumari, Renu; Besser, Heino; Scharnweber, Tim; Majumdar, Jyotsna Dutta

2015-01-01

Highlights: • Texturing of Ti–6Al–4V with linear and dimple patterns are developed with ArF laser. • Linear textures have width of 25 μm and are at an interval of 20 μm. • Dimple textures are equi-spaced and have a diameter of 60 μm. • Significant refinement of microstructure in textured zone as compared to substrate. • Increased wettability of the textured surface against simulated body fluid. - Abstract: In the present study, a detailed study of the characterization of laser-surface textured titanium alloy (Ti–6Al–4V) with line and dimple geometry developed by using an ArF excimer laser operating at a wavelength of 193 nm with a pulse length of 5 ns is undertaken. The characterization of the textured surface (both the top surface and cross section) is carried out by scanning electron microscopy, electron back scattered diffraction (EBSD) technique and X-ray diffraction techniques. There is refinement of microstructure along with presence of titanium oxides (rutile, anatase and few Ti_2O_3 phase) in the textured surface as compared to as-received one. The area fractions of linear texture and dimple texture measured by image analysis software are 45% and 20%, respectively. The wettability is increased after laser texturing. The total surface energy is decreased due to linear (29.6 mN/m) texturing and increased due to dimple (67.6 mN/m) texturing as compared to as-received Ti–6Al–4V (37 mN/m). The effect of polar component is more in influencing the surface energy of textured surface.

Simple method for the characterization of intense Laguerre-Gauss vector vortex beams

Science.gov (United States)

Allahyari, E.; JJ Nivas, J.; Cardano, F.; Bruzzese, R.; Fittipaldi, R.; Marrucci, L.; Paparo, D.; Rubano, A.; Vecchione, A.; Amoruso, S.

2018-05-01

We report on a method for the characterization of intense, structured optical fields through the analysis of the size and surface structures formed inside the annular ablation crater created on the target surface. In particular, we apply the technique to laser ablation of crystalline silicon induced by femtosecond vector vortex beams. We show that a rapid direct estimate of the beam waist parameter is obtained through a measure of the crater radii. The variation of the internal and external radii of the annular crater as a function of the laser pulse energy, at fixed number of pulses, provides another way to evaluate the beam spot size through numerical fitting of the obtained experimental data points. A reliable estimate of the spot size is of paramount importance to investigate pulsed laser-induced effects on the target material. Our experimental findings offer a facile way to characterize focused, high intensity complex optical vector beams which are more and more applied in laser-matter interaction experiments.

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.

Preparation of ceramic materials for surface characterization

International Nuclear Information System (INIS)

Zipperian, D.C.

1989-01-01

This paper discusses how microstructural preparation permits a microscopic analysis of a material's internal structure, which is related to the physical properties of the material. Today, numerous microstructural quantitative and qualitative measurements are commonly utilized. Several of these include phase determination, phase hardness, phase distribution, grain size and shape, and porosity and size distribution. The most widely used surface characterization techniques are optical microscopy, electron microscopy, and x-ray microscopy. Optical microscopy includes both transmitted-and reflected-light techniques and requires a surface preparation prior to analysis. Transmitted-light microscopy samples require thinning and polishing of both sides of the sample, whereas reflected light techniques require polishing of only one side of the sample

Design and characterization of textured surfaces for applications in the food industry

Science.gov (United States)

Lazzini, G.; Romoli, L.; Blunt, L.; Gemini, L.

2017-12-01

The aim of this work is to design, manufacture and characterize surface morphologies on AISI 316L stainless steel produced by a custom designed laser-texturing strategy. Surface textures were characterized at a micrometric dimension in terms of areal parameters compliant with ISO 25178, and correlations between these parameters and processing parameters (e.g. laser energy dose supplied to the material, repetition rate of the laser pulses and scanning velocity) were investigated. Preliminary efforts were devoted to the research of special requirements for surface morphology that, according to the commonly accepted research on the influence of surface roughness on cellular adhesion on surfaces, should discourage the formation of biofilms. The topographical characterization of the surfaces was performed with a coherence scanning interferometer. This approach showed that increasing doses of energy to the surfaces increased the global level of roughness as well as the surface complexity. Moreover, the behavior of the parameters S pk, S vk also indicates that, due to the ablation process, an increase in the energy dose causes an average increase in the height of the highest peaks and in the depth of the deepest dales. The study of the density of peaks S pd showed that none of the surfaces analyzed here seem to perfectly match the conditions dictated by the theories on cellular adhesion to confer anti-biofouling properties. However, this result seems to be mainly due to the limits of the resolving power of coherence scanning interferometry, which does not allow the resolution of sub-micrometric features which could be crucial in the prevention of cellular attachment.

Surface topography and morphology characterization of PIII irradiated silicon surface

International Nuclear Information System (INIS)

Sharma, Satinder K.; Barthwal, Sumit

2008-01-01

The effect of plasma immersion ion implantation (PIII) treatment on silicon surfaces was investigated by micro-Raman and atomic force microscopy (AFM) technique. The surface damage was given by the implantation of carbon, nitrogen, oxygen and argon ions using an inductively coupled plasma (ICP) source at low pressure. AFM studies show that surface topography of the PIII treated silicon wafers depend on the physical and chemical nature of the implanted species. Micro-Raman spectra indicate that the significant reduction of intensity of Raman peak after PIII treatment. Plasma immersion ion implantation is a non-line-of-sight ion implantation method, which allows 3D treatment of materials. Therefore, PIII based surface modification and plasma immersion ion deposition (PIID) coatings are applied in a wide range of situations.

Surface characterization and surface electronic structure of organic quasi-one-dimensional charge transfer salts

DEFF Research Database (Denmark)

Sing, M.; Schwingenschlögl, U.; Claessen, R.

2003-01-01

We have thoroughly characterized the surfaces of the organic charge-transfer salts TTF-TCNQ and (TMTSF)(2)PF6 which are generally acknowledged as prototypical examples of one-dimensional conductors. In particular x-ray-induced photoemission spectroscopy turns out to be a valuable nondestructive...

Evolution of the transfer function characterization of surface scatter phenomena

Science.gov (United States)

Harvey, James E.; Pfisterer, Richard N.

2016-09-01

Based upon the empirical observation that BRDF measurements of smooth optical surfaces exhibited shift-invariant behavior when plotted versus    o , the original Harvey-Shack (OHS) surface scatter theory was developed as a scalar linear systems formulation in which scattered light behavior was characterized by a surface transfer function (STF) reminiscent of the optical transfer function (OTF) of modern image formation theory (1976). This shift-invariant behavior combined with the inverse power law behavior when plotting log BRDF versus log   o was quickly incorporated into several optical analysis software packages. Although there was no explicit smooth-surface approximation in the OHS theory, there was a limitation on both the incident and scattering angles. In 1988 the modified Harvey-Shack (MHS) theory removed the limitation on the angle of incidence; however, a moderate-angle scattering limitation remained. Clearly for large incident angles the BRDF was no longer shift-invariant as a different STF was now required for each incident angle. In 2011 the generalized Harvey-Shack (GHS) surface scatter theory, characterized by a two-parameter family of STFs, evolved into a practical modeling tool to calculate BRDFs from optical surface metrology data for situations that violate the smooth surface approximation inherent in the Rayleigh-Rice theory and/or the moderate-angle limitation of the Beckmann-Kirchhoff theory. And finally, the STF can be multiplied by the classical OTF to provide a complete linear systems formulation of image quality as degraded by diffraction, geometrical aberrations and surface scatter effects from residual optical fabrication errors.

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

Surface characterization and corrosion behavior of micro-arc oxidized Ti surface modified with hydrothermal treatment and chitosan coating

International Nuclear Information System (INIS)

Neupane, Madhav Prasad; Park, Il Song; Lee, Min Ho

2014-01-01

In the present work, we describe the surface modification of commercially pure titanium (CP-Ti) by a composite/multilayer coating approach for biomedical applications. CP-Ti samples were treated by micro-arc oxidation (MAO) and subsequently some of the samples were coated with chitosan (Chi) by dip coating method, while others were subjected to hydrothermal treatment (HT) followed by chitosan coating. The MAO, MAO/Chi, and MAO/HT/Chi coated Ti were characterized and their characteristics were compared with CP-Ti. X-ray diffraction and scanning electron microscopy were used to assess the structural and morphological characteristics. The average surface roughness was determined using a surface profilometer. The corrosion resistance of untreated and surface modified Ti in commercial saline at 298 K was evaluated by potentiodynamic polarization test. The results indicated that the chitosan coating is very well integrated with the MAO and MAO/HT coating by physically interlocking itself with the coated layer and almost sealed all the pores. The surface roughness of hydrothermally treated and chitosan coated MAO film was superior evidently to that with other sample groups. The corrosion studies demonstrated that the MAO, hydrothermally treated and chitosan coated sample enhanced the corrosion resistance of titanium. The result indicates that fabrication of hydrothermally treated MAO surface coatings with chitosan is a significant approach to protect the titanium from corrosion, hence enhancing the potential use of titanium as bio-implants. - Highlights: • Micro-arc oxidized (MAO) and hydrothermally treated (HT) Ti surfaces are coated with chitosan (Chi). • The MAO/HT/Chi surface exhibits pores sealing and enhanced the surface roughness. • The MAO/HT/Chi surface significantly increase the corrosion resistance. • The MAO/HT/Chi can be a potential surface of titanium for bio-implants

3D-characterization method and morphological filtering for the assessment and the design of friction optimized surfaces

International Nuclear Information System (INIS)

Groeger, S; Dietzsch, M; Burkhardt, T

2011-01-01

For a specific manipulation of friction surfaces it is important to measure and calculate geometrical parameters to derive the tribological behavior. The new functional approach presented in this paper is the calculation of the characteristic lateral extension of the real contact surface as well as the representative contact radius by applying morphological filters to a 3D-set of data. All surface characteristics, including form, waviness, roughness as well as defined microstructures, are extracted holistically with a 3D Coordinate Measuring Instrument or a Form Measuring Instrument, but with the smallest available tip radius. The paper presents the benefit of this holistic extraction method and the application of morphological filtering for the description of the contact form (plateau or sphere), the real contact surface, number of contacts, the typical contact radius and the typical lateral extension of the micro contact plateaus.

Characterizing the effects of regolith surface roughness on photoemission from surfaces in space

Science.gov (United States)

Dove, A.; Horanyi, M.; Wang, X.

2017-12-01

Surfaces of airless bodies and spacecraft in space are exposed to a variety of charging environments. A balance of currents due to plasma bombardment, photoemission, electron and ion emission and collection, and secondary electron emission determines the surface's charge. Photoelectron emission is the dominant charging process on sunlit surfaces in the inner solar system due to the intense solar UV radiation. This can result in a net positive surface potential, with a cloud of photoelectrons immediately above the surface, called the photoelectron sheath. Conversely, the unlit side of the body will charge negatively due the collection of the fast-moving solar wind electrons. The interaction of charged dust grains with these positively and negatively charged surfaces, and within the photoelectron and plasma sheaths may explain the occurrence of dust lofting, levitation and transport above the lunar surface. The surface potential of exposed objects is also dependent on the material properties of their surfaces. Composition and particle size primarily affect the quantum efficiency of photoelectron generation; however, surface roughness can also control the charging process. In order to characterize these effects, we have conducted laboratory experiments to examine the role of surface roughness in generating photoelectrons in dedicated laboratory experiments using solid and dusty surfaces of the same composition (CeO2), and initial comparisons with JSC-1 lunar simulant. Using Langmuir probe measurements, we explore the measured potentials above insulating surfaces exposed to UV and an electric field, and we show that the photoemission current from a dusty surface is largely reduced due to its higher surface roughness, which causes a significant fraction of the emitted photoelectrons to be re-absorbed within the surface. We will discuss these results in context of similar situations on planetary surfaces.

Modeling and evaluating of surface roughness prediction in micro-grinding on soda-lime glass considering tool characterization

Science.gov (United States)

Cheng, Jun; Gong, Yadong; Wang, Jinsheng

2013-11-01

The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality processing surface. Therefore, a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography is proposed in this paper. The differences of material removal mechanism between convention grinding process and micro-grinding process are analyzed. Topography characterization has been done on micro-grinding tools which are fabricated by electroplating. Models of grain density generation and grain interval are built, and new predicting model of micro-grinding surface roughness is developed. In order to verify the precision and application effect of the surface roughness prediction model proposed, a micro-grinding orthogonally experiment on soda-lime glass is designed and conducted. A series of micro-machining surfaces which are 78 nm to 0.98 μm roughness of brittle material is achieved. It is found that experimental roughness results and the predicting roughness data have an evident coincidence, and the component variable of describing the size effects in predicting model is calculated to be 1.5×107 by reverse method based on the experimental results. The proposed model builds a set of distribution to consider grains distribution densities in different protrusion heights. Finally, the characterization of micro-grinding tools which are used in the experiment has been done based on the distribution set. It is concluded that there is a significant coincidence between surface prediction data from the proposed model and measurements from experiment results. Therefore, the effectiveness of the model is demonstrated. This paper proposes a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion

Evaluation of Two Surface Sampling Methods for Microbiological and Chemical Analyses To Assess the Presence of Biofilms in Food Companies.

Science.gov (United States)

Maes, Sharon; Huu, Son Nguyen; Heyndrickx, Marc; Weyenberg, Stephanie van; Steenackers, Hans; Verplaetse, Alex; Vackier, Thijs; Sampers, Imca; Raes, Katleen; Reu, Koen De

2017-12-01

Biofilms are an important source of contamination in food companies, yet the composition of biofilms in practice is still mostly unknown. The chemical and microbiological characterization of surface samples taken after cleaning and disinfection is very important to distinguish free-living bacteria from the attached bacteria in biofilms. In this study, sampling methods that are potentially useful for both chemical and microbiological analyses of surface samples were evaluated. In the manufacturing facilities of eight Belgian food companies, surfaces were sampled after cleaning and disinfection using two sampling methods: the scraper-flocked swab method and the sponge stick method. Microbiological and chemical analyses were performed on these samples to evaluate the suitability of the sampling methods for the quantification of extracellular polymeric substance components and microorganisms originating from biofilms in these facilities. The scraper-flocked swab method was most suitable for chemical analyses of the samples because the material in these swabs did not interfere with determination of the chemical components. For microbiological enumerations, the sponge stick method was slightly but not significantly more effective than the scraper-flocked swab method. In all but one of the facilities, at least 20% of the sampled surfaces had more than 10 2 CFU/100 cm 2 . Proteins were found in 20% of the chemically analyzed surface samples, and carbohydrates and uronic acids were found in 15 and 8% of the samples, respectively. When chemical and microbiological results were combined, 17% of the sampled surfaces were contaminated with both microorganisms and at least one of the analyzed chemical components; thus, these surfaces were characterized as carrying biofilm. Overall, microbiological contamination in the food industry is highly variable by food sector and even within a facility at various sampling points and sampling times.

Surface Characterization of a Paper Web at the Wet End

International Nuclear Information System (INIS)

Abidi, B.R.; Goddard, J.S.; Sari-Sarraf, H.

1999-01-01

We present an algorithm for the detection and representation of structures and non-uniformities on the surface of a paper web at the wet end (slurry). This image processing/analysis algorithm is developed as part of a complete on-line web characterization system. Images of the slurry, carried by a fast moving table, are obtained using a stroboscopic light and a CCD camera. The images have very poor contrast and contain noise from a variety of sources. Those sources include the acquisition system itself, the lighting, the vibrations of the moving table being imaged, and the scattering water from the same table's movement. After many steps of enhancement, conventional edge detection methods were still inconclusive and were discarded. The facet model algorithm, is applied to the images and is found successful in detecting the various topographic characteristics of the surface of the slurry. Pertinent topographic elements are retained and a filtered image is computed based on the general appearance and characteristics of the structures in question. Morphological operators are applied to detect and segment regions of interest. Those regions are then filtered according to their size, elongation, and orientation.Their bounding rectangles are computed and superimposed on the original image. Real time implementation of this algorithm for on-line use is also addressed in this paper. The algorithm is tested on over 500 images of slurry and is found to detect nonuniformities on all 500 images. Locating and characterizing all different size structures is also achieved on all 500 images of the web

CHARACTERIZATION OF THE ELECTROPHYSICAL PROPERTIES OF SILICON-SILICON DIOXIDE INTERFACE USING PROBE ELECTROMETRY METHODS

Directory of Open Access Journals (Sweden)

V. А. Pilipenko

2017-01-01

Full Text Available Introduction of submicron design standards into microelectronic industry and a decrease of the gate dielectric thickness raise the importance of the analysis of microinhomogeneities in the silicon-silicon dioxide system. However, there is very little to no information on practical implementation of probe electrometry methods, and particularly scanning Kelvin probe method, in the interoperational control of real semiconductor manufacturing process. The purpose of the study was the development of methods for nondestructive testing of semiconductor wafers based on the determination of electrophysical properties of the silicon-silicon dioxide interface and their spatial distribution over wafer’s surface using non-contact probe electrometry methods.Traditional C-V curve analysis and scanning Kelvin probe method were used to characterize silicon- silicon dioxide interface. The samples under testing were silicon wafers of KEF 4.5 and KDB 12 type (orientation <100>, diameter 100 mm.Probe electrometry results revealed uniform spatial distribution of wafer’s surface potential after its preliminary rapid thermal treatment. Silicon-silicon dioxide electric potential values were also higher after treatment than before it. This potential growth correlates with the drop in interface charge density. At the same time local changes in surface potential indicate changes in surface layer structure.Probe electrometry results qualitatively reflect changes of interface charge density in silicon-silicon dioxide structure during its technological treatment. Inhomogeneities of surface potential distribution reflect inhomogeneity of damaged layer thickness and can be used as a means for localization of interface treatment defects.

3D scanning electron microscopy applied to surface characterization of fluorosed dental enamel.

Science.gov (United States)

Limandri, Silvina; Galván Josa, Víctor; Valentinuzzi, María Cecilia; Chena, María Emilia; Castellano, Gustavo

2016-05-01

The enamel surfaces of fluorotic teeth were studied by scanning electron stereomicroscopy. Different whitening treatments were applied to 25 pieces to remove stains caused by fluorosis and their surfaces were characterized by stereomicroscopy in order to obtain functional and amplitude parameters. The topographic features resulting for each treatment were determined through these parameters. The results obtained show that the 3D reconstruction achieved from the SEM stereo pairs is a valuable potential alternative for the surface characterization of this kind of samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Deposition and characterization of noble metal onto surfaces of 304l stainless steel

International Nuclear Information System (INIS)

Contreras R, A.; Arganis J, C. R.; Aguilar T, J. A.; Medina A, A. L.

2010-10-01

Noble metal chemical addition (NMCA) plus hydrogen water chemistry is an industry-wide accepted approach for potential intergranular stress corrosion cracking mitigation of BWR internals components. NMCA is a method of applying noble metal onto BWR internals surfaces using reactor water as the transport medium that causes the deposition of noble metal from the liquid onto surfaces. In this work different platinum concentration solutions were deposited onto pre-oxidized surfaces of 304l steel at 180 C during 48 hr in an autoclave. In order to simulate the zinc water conditions, deposits of Zn and Pt-Zn were also carried out. The solutions used to obtain the deposits were: sodium hexahydroxyplatinate (IV), zinc nitrate hydrate and zinc oxide. The deposits obtained were characterized by scanning electron microscopy and X-ray diffraction. Finally, the electrochemical corrosion potential of pre-oxidized samples with Pt deposit were obtained and compared with the electrochemical corrosion potential of only pre-oxidized samples. (Author)

Fast Characterization of Moving Samples with Nano-Textured Surfaces

DEFF Research Database (Denmark)

Madsen, Morten Hannibal; Hansen, Poul-Erik; Zalkovskij, Maksim

2015-01-01

Characterization of structures using conventional optical microscopy is restricted by the diffraction limit. Techniques like atomic force and scanning electron microscopy can investigate smaller structures but are very time consuming. We show that using scatterometry, a technique based on optical...... diffraction, integrated into a commercial light microscope we can characterize nano-textured surfaces in a few milliseconds. The adapted microscope has two detectors, a CCD camera used to easily find an area of interest and a spectrometer for the measurements. We demonstrate that the microscope has...

Characterization of the surface and interfacial properties of the lamina splendens

Science.gov (United States)

Rexwinkle, Joe T.; Hunt, Heather K.; Pfeiffer, Ferris M.

2017-06-01

Joint disease affects approximately 52.5 million patients in the United States alone, costing 80.8 billion USD in direct healthcare costs. The development of treatment programs for joint disease and trauma requires accurate assessment of articular cartilage degradation. The articular cartilage is the interfacial tissue between articulating surfaces, such as bones, and acts as low-friction interfaces. Damage to the lamina splendens, which is the articular cartilage's topmost layer, is an early indicator of joint degradation caused by injury or disease. By gaining comprehensive knowledge on the lamina splendens, particularly its structure and interfacial properties, researchers could enhance the accuracy of human and animal biomechanical models, as well as develop appropriate biomimetic materials for replacing damaged articular cartilage, thereby leading to rational treatment programs for joint disease and injury. Previous studies that utilize light, electron, and force microscopy techniques have found that the lamina splendens is composed of collagen fibers oriented parallel to the cartilage surface and encased in a proteoglycan matrix. Such orientation maximizes wear resistance and proteoglycan retention while promoting the passage of nutrients and synovial fluid. Although the structure of the lamina splendens has been explored in the literature, the low-friction interface of this tissue remains only partially characterized. Various functional models are currently available for the interface, such as pure boundary lubrication, thin films exuded under pressure, and sheets of trapped proteins. Recent studies suggest that each of these lubrication models has certain advantages over one another. Further research is needed to fully model the interface of this tissue. In this review, we summarize the methods for characterizing the lamina splendens and the results of each method. This paper aims to serve as a resource for existing studies to date and a roadmap of the

Immobilization of glucoamylase on ceramic membrane surfaces modified with a new method of treatment utilizing SPCP-CVD.

Science.gov (United States)

Ida; Matsuyama; Yamamoto

2000-07-01

Glucoamylase, as a model enzyme, was immobilized on a ceramic membrane modified by surface corona discharge induced plasma chemical process-chemical vapor deposition (SPCP-CVD). Characterizations of the immobilized enzyme were then discussed. Three kinds of ceramic membranes with different amounts of amino groups on the surface were prepared utilizing the SPCP-CVD method. Each with 1-time, 3-times and 5-times surface modification treatments and used for supports in glucoamylase immobilization. The amount of immobilized glucoamylase increased with the increase in the number of surface modification treatments and saturated to a certain maximum value estimated by a two-dimensional random packing. The operational stability of the immobilized glucoamylase also increased with the increase in the number of the surface treatment. It was almost the same as the conventional method, while the activity of immobilized enzyme was higher. The results indicated the possibility of designing the performance of the immobilized enzyme by controlling the amount of amino groups. The above results showed that the completely new surface modification method using SPCP was effective in modifying ceramic membranes for enzyme immobilization.

Characterizing the statistical properties of protein surfaces

Science.gov (United States)

Bak, Ji Hyun; Bitbol, Anne-Florence; Bialek, William

Proteins and their interactions form the body of the signaling transduction pathway in many living systems. In order to ensure the accuracy as well as the specificity of signaling, it is crucial that proteins recognize their correct interaction partners. How difficult, then, is it for a protein to discriminate its correct interaction partner(s) from the possibly large set of other proteins it may encounter in the cell? An important ingredient of recognition is shape complementarity. The ensemble of protein shapes should be constrained by the need for maintaining functional interactions while avoiding spurious ones. To address this aspect of protein recognition, we consider the ensemble of proteins in terms of the shapes of their surfaces. We take into account the high-resolution structures of E.coli non-DNA-binding cytoplasmic proteins, retrieved from the Protein Data Bank. We aim to characterize the statistical properties of the protein surfaces at two levels: First, we study the intrinsic dimensionality at the level of the ensemble of the surface objects. Second, at the level of the individual surfaces, we determine the scale of shape variation. We further discuss how the dimensionality of the shape space is linked to the statistical properties of individual protein surfaces. Jhb and WB acknowledge support from National Science Foundation Grants PHY-1305525 and PHY-1521553. AFB acknowledges support from the Human Frontier Science Program.

Surface structure analysis by means of Rutherford scattering: methods to study surface relaxation

International Nuclear Information System (INIS)

Turkenburg, W.C.; Soszka, W.; Saris, F.W.; Kersten, H.H.; Colenbrander, B.G.

1976-01-01

The use of Rutherford backscattering for structural analysis of single crystal surfaces is reviewed, and a new method is introduced. With this method, which makes use of the channeling and blocking phenomenon of light ions of medium energy, surface atoms can be located with a precision of 0.02 A. This is demonstrated in a measurement of surface relaxation for the Cu(110) surface. (Auth.)

Multi-method characterization of low-level radioactive waste at two Sandia National Laboratories environmental restoration sites

International Nuclear Information System (INIS)

Johnson, C.E. Jr.; Galloway, R.B.; Dotson, P.W.

1999-01-01

This paper discusses the application of multiple characterization methods to radioactive wastes generated by the Sandia National Laboratories/New Mexico (SNL/NM) Environmental Restoration (ER) Project during the excavation of buried materials at the Classified Waste Landfill (CWLF) and the Radioactive Waste Landfill (RWL). These waste streams include nuclear weapon components and other refuse that are surface contaminated or contain sealed radioactive sources with unknown radioactivity content. Characterization of radioactive constituents in RWL and CWLF waste has been problematic, due primarily to the lack of documented characterization data prior to burial. A second difficulty derives from the limited information that ER project personnel have about weapons component design and testing that was conducted in the early days of the Cold War. To reduce the uncertainties and achieve the best possible waste characterization, the ER Project has applied both project-specific and industry-standard characterization methods that, in combination, serve to define the types and quantities of radionuclide constituents in the waste. The resulting characterization data have been used to develop waste profiles for meeting disposal site waste acceptance criteria

Preparation and characterization of ethylenediamine and cysteamine plasma polymerized films on piezoelectric quartz crystal surfaces for a biosensor

International Nuclear Information System (INIS)

Mutlu, Selma; Coekeliler, Dilek; Shard, Alex; Goktas, Hilal; Ozansoy, Berna; Mutlu, Mehmet

2008-01-01

This paper describes a method for the modification of quartz crystal surfaces to be used as a transducer in biosensors that allow recognition and quantification of certain biomolecules (antibodies, enzymes, proteins, etc). Quartz crystal sensors were modified by a plasma based electron beam generator in order to detect the level of the toxin histamine within biological liquids (blood, serum) and food (wine, cheese, fish etc.). Cysteamine and ethylenediamine were used as precursors in the plasma. After each modification step, the layers on the quartz crystal were characterized by frequency measurements. Modified surfaces were also characterized by contact angle, X-ray photoelectron spectroscopy and atomic force microscopy to determine the physical and chemical characteristics of the surfaces after each modification. Finally, the performance of the sensors were tested by the response to histamine via frequency shifts. The frequency shifts of the sensors prepared by plasma polymerization of ethylenediamine and cysteamine were approximately 3230 Hz and 5630 Hz, respectively, whereas the frequency change of the unmodified crystal surface was around 575 Hz

Formation and surface characterization of nanostructured Al2O3 ...

Indian Academy of Sciences (India)

Administrator

Page 1. Electronic Supplementary Material. Graphical abstract. Formation and surface characterization of nanostructured Al2O3–TiO2 coatings by Vairamuthu Raj and Mohamed Sirajudeen Mumjitha. (pp 1411–1418).

Surface characterization of adsorbed asphaltene on a stainless steel surface

International Nuclear Information System (INIS)

Abdallah, W.A.; Taylor, S.D.

2007-01-01

X-ray photoelectron spectroscopy was used to characterize a single layer of adsorbed asphaltene on a metallic surface. The deposits were created by immersing a stainless steel disc into a dilute asphaltene solution with either toluene or dichloromethane as the solvent, although the toluene solution allowed for better control of the adsorbed asphaltene layer and less atmospheric oxygen contamination. The analyses for C 1s, S 2p 3/2 , N 1s and O 1s photoemission peaks indicated that different functional groups are present in the asphaltene layer including carboxylic, pyrrolic, pyridininc, thiophenic and sulfite, with slight differences in their binding energies

Fabrication and characterization of stable superhydrophobic surface with good friction-reducing performance on Al foil

Energy Technology Data Exchange (ETDEWEB)

Li, Peipei [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Chen, Xinhua, E-mail: xuc0374@hotmail.com [College of Chemistry and Chemical Engineering, Xuchang University, Xuchang 461000 (China); Yang, Guangbin; Yu, Laigui [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Zhang, Pingyu, E-mail: pingyu@henu.edu.cn [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China)

2014-05-01

Graphical abstract: A lotus-leaf-like hierarchical structure was successfully created on Al foil by a facile three-step solution–immersion method. As-obtained etched-immersed Al/STA rough surface contains interconnected convex–concave micro-structure and uniformly distributed nano-sheets that endow the surface with excellent superhydrophobicity (WCA: 164.2°; WSA: below 5°). Besides, the as-prepared etched-immersed Al/STA superhydrophobic surface on Al foil exhibits good friction-reducing ability and stable superhydrophobicity. - Highlights: • A stable superhydrophobic surface was created on aluminum foil by a facile three-step solution–immersion method. • A lotus-leaf-like hierarchical structure consists of interconnected convex–concave micro-structure and uniformly distributed nano-sheets has been constructed on the aluminum surface. • The superhydrophobic surfaces on aluminum substrate showing effective friction-reducing performance and self-cleaning ability. - Abstract: A lotus-leaf-like hierarchical structure with superhydrophobicity was created on Al foil by a facile three-step solution–immersion method involving etching in hydrochloric acid solution and immersing in hot water as well as surface-modification by stearic acid (denoted as STA). As-prepared etched-immersed Al/STA rough surface was characterized by means of scanning electron microscopy and X-ray photoelectron spectroscopy. Moreover, the water contact angles and water sliding angles of as-prepared etched-immersed Al/STA rough surface were measured, and the friction-reducing performance and self-cleaning ability of the as-prepared surface were also evaluated. Results indicate that the etched-immersed Al/STA rough surface consists of interconnected convex–concave micro-structure and uniformly distributed nano-sheets. Besides, it exhibits stable superhydrophobicity and good friction-reducing ability. Namely, it has a contact angle of water as high as 164.2° and a water sliding

Fabrication and characterization of stable superhydrophobic surface with good friction-reducing performance on Al foil

International Nuclear Information System (INIS)

Li, Peipei; Chen, Xinhua; Yang, Guangbin; Yu, Laigui; Zhang, Pingyu

2014-01-01

Graphical abstract: A lotus-leaf-like hierarchical structure was successfully created on Al foil by a facile three-step solution–immersion method. As-obtained etched-immersed Al/STA rough surface contains interconnected convex–concave micro-structure and uniformly distributed nano-sheets that endow the surface with excellent superhydrophobicity (WCA: 164.2°; WSA: below 5°). Besides, the as-prepared etched-immersed Al/STA superhydrophobic surface on Al foil exhibits good friction-reducing ability and stable superhydrophobicity. - Highlights: • A stable superhydrophobic surface was created on aluminum foil by a facile three-step solution–immersion method. • A lotus-leaf-like hierarchical structure consists of interconnected convex–concave micro-structure and uniformly distributed nano-sheets has been constructed on the aluminum surface. • The superhydrophobic surfaces on aluminum substrate showing effective friction-reducing performance and self-cleaning ability. - Abstract: A lotus-leaf-like hierarchical structure with superhydrophobicity was created on Al foil by a facile three-step solution–immersion method involving etching in hydrochloric acid solution and immersing in hot water as well as surface-modification by stearic acid (denoted as STA). As-prepared etched-immersed Al/STA rough surface was characterized by means of scanning electron microscopy and X-ray photoelectron spectroscopy. Moreover, the water contact angles and water sliding angles of as-prepared etched-immersed Al/STA rough surface were measured, and the friction-reducing performance and self-cleaning ability of the as-prepared surface were also evaluated. Results indicate that the etched-immersed Al/STA rough surface consists of interconnected convex–concave micro-structure and uniformly distributed nano-sheets. Besides, it exhibits stable superhydrophobicity and good friction-reducing ability. Namely, it has a contact angle of water as high as 164.2° and a water sliding

Waste Volume Reduction Using Surface Characterization and Decontamination By Laser Ablation

International Nuclear Information System (INIS)

Pellin, Michael J.; Savina, Michael R.; Reed, Claude B.; Zhiyue, Xu; Yong, Wang

2000-01-01

The U.S. Department of Energy's nuclear complex, a nation-wide system of facilities for research and production of nuclear materials and weapons, contains large amounts of radioactively contaminated concrete[1]. This material must be disposed of prior to the decommissioning of the various sites. Often the radioactive contaminants in concrete occupy only the surface and near-surface (∼3-6 mm deep) regions of the material. Since many of the structures such as walls and floors are 30 cm or more thick, it makes environmental and economic sense to try to remove and store only the thin contaminated layer rather than to treat the entire structure as waste. Current mechanical removal methods, known as scabbling, are slow and labor intensive, suffer from dust control problems, and expose workers to radiation fields. Improved removal methods are thus in demand[2-5]. Prior to decontamination, the surface must be characterized to determine the types and amounts of contaminants present i n order to decide on an appropriate cleaning strategy. Contamination occurs via exposure to air and water-borne radionuclides and by neutron activation. The radionuclides of greatest concern are (in order of abundance) [1]: 137Cs and 134Cs, 238U, 60Co, and 90Sr, followed by 3H, radioactive iodine, and a variety of Eu isotopes and transuranics. A system capable of on- line analysis is valuable since operators can determine the type of contaminants in real time and make more efficient use of costly sampling and characterization techniques. Likewise, the removed waste itself must be analyzed to insure that proper storage and monitoring techniques are used. The chemical speciation of radionuclides in concrete is largely unknown. Concrete is a complex material comprising many distinct chemical and physical phases on a variety of size scales[6-8]. Most studies of radionuclides in cements and concrete are for the most part restricted to phenomenological treatments of diffusion of ion s, particularly

Electrochemical characterization of organosilane-functionalized nanostructured ITO surfaces

Energy Technology Data Exchange (ETDEWEB)

Pruna, R., E-mail: rpruna@el.ub.edu; Palacio, F.; López, M. [SIC, Departament d' Enginyeries: Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain); Pérez, J. [Nanobioengineering Group, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, E-08028 Barcelona (Spain); Mir, M. [Nanobioengineering Group, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, E-08028 Barcelona (Spain); Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Monforte de Lemos 3-5 Pabellón 11, E-28029 Madrid (Spain); Blázquez, O.; Hernández, S.; Garrido, B. [MIND-IN" 2UB, Departament d' Enginyeries: Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain)

2016-08-08

The electroactivity of nanostructured indium tin oxide (ITO) has been investigated for its further use in applications such as sensing biological compounds by the analysis of redox active molecules. ITO films were fabricated by using electron beam evaporation at different substrate temperatures and subsequently annealed for promoting their crystallization. The morphology of the deposited material was monitored by scanning electron microscopy, confirming the deposition of either thin films or nanowires, depending on the substrate temperature. Electrochemical surface characterization revealed a 45 % increase in the electroactive surface area of nanostructured ITO with respect to thin films, one third lower than the geometrical surface area variation determined by atomic force microscopy. ITO surfaces were functionalized with a model organic molecule known as 6-(ferrocenyl)hexanethiol. The chemical attachment was done by means of a glycidoxy compound containing a reactive epoxy group, the so-called 3-glycidoxypropyltrimethoxy-silane. ITO functionalization was useful for determining the benefits of nanostructuration on the surface coverage of active molecules. Compared to ITO thin films, an increase in the total peak height of 140 % was observed for as-deposited nanostructured electrodes, whereas the same measurement for annealed electrodes resulted in an increase of more than 400 %. These preliminary results demonstrate the ability of nanostructured ITO to increase the surface-to-volume ratio, conductivity and surface area functionalization, features that highly benefit the performance of biosensors.

Electrochemical characterization of organosilane-functionalized nanostructured ITO surfaces

International Nuclear Information System (INIS)

Pruna, R.; Palacio, F.; López, M.; Pérez, J.; Mir, M.; 2UB, Departament d'Enginyeries: Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain))" data-affiliation=" (MIND-IN2UB, Departament d'Enginyeries: Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain))" >Blázquez, O.; 2UB, Departament d'Enginyeries: Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain))" data-affiliation=" (MIND-IN2UB, Departament d'Enginyeries: Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain))" >Hernández, S.; 2UB, Departament d'Enginyeries: Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain))" data-affiliation=" (MIND-IN2UB, Departament d'Enginyeries: Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain))" >Garrido, B.

2016-01-01

The electroactivity of nanostructured indium tin oxide (ITO) has been investigated for its further use in applications such as sensing biological compounds by the analysis of redox active molecules. ITO films were fabricated by using electron beam evaporation at different substrate temperatures and subsequently annealed for promoting their crystallization. The morphology of the deposited material was monitored by scanning electron microscopy, confirming the deposition of either thin films or nanowires, depending on the substrate temperature. Electrochemical surface characterization revealed a 45 % increase in the electroactive surface area of nanostructured ITO with respect to thin films, one third lower than the geometrical surface area variation determined by atomic force microscopy. ITO surfaces were functionalized with a model organic molecule known as 6-(ferrocenyl)hexanethiol. The chemical attachment was done by means of a glycidoxy compound containing a reactive epoxy group, the so-called 3-glycidoxypropyltrimethoxy-silane. ITO functionalization was useful for determining the benefits of nanostructuration on the surface coverage of active molecules. Compared to ITO thin films, an increase in the total peak height of 140 % was observed for as-deposited nanostructured electrodes, whereas the same measurement for annealed electrodes resulted in an increase of more than 400 %. These preliminary results demonstrate the ability of nanostructured ITO to increase the surface-to-volume ratio, conductivity and surface area functionalization, features that highly benefit the performance of biosensors.

Particle desorption mass spectrometric surface characterization

International Nuclear Information System (INIS)

Summers, W.R.

1986-01-01

The feasibility of utilizing 252 Cf-Particle Desorption Mass Spectrometry (PDMS) to characterize the surface region of solid samples has been evaluated. The PDMS experiment was adapted to an ultrahigh vacuum (UHV) environment and was configured so as to allow the analysis of thick as well as thin samples. This apparatus included an in situ sputter cleaning/depth profiling facility. The mass resolution was variable from 300 to 200 at 133 daltons by changing the drift length from 27 cm to 20 cm. Desorbed ions were focused by using either a dual grid assembly or an einzel lens. The overall instrumental transmission efficiency with the einzel lens operative was approximately 50%. The applicability of 252 Cf-PDMS to samples that were thick and insulating was demonstrated in the analysis of geological specimens. Pollucite, Microcline, Amblygonite, and Lepidolite were analyzed without complications associated with sample thickness or charge accumulation. Substitution occurring between the alkali metals in the environment was observed by PDMS and was corroborated by SIMS, XPS, and EMP analyses. The analysis of NBM SRM glasses addressed the suitability of combining the PDMS technique was sputter etching. This application demonstrated the ability of this technique to sense changes in the chemical environment brought about by sputter cleaning. The analysis of these samples also allowed the estimation of detection limits for lithium, rubidium, and cesium in a glass matrix as 300 ppm, 400 ppm, and 400 ppm, respectively. Sputter depth profiling combined with 252 Cf-PDMS analysis of an aluminum layer on a silicon substrate established the utility of the PDMS technique in surface characterization

Modeling, Fabrication and Characterization of Scalable Electroless Gold Plated Nanostructures for Enhanced Surface Plasmon Resonance

Science.gov (United States)

Jang, Gyoung Gug

The scientific and industrial demand for controllable thin gold (Au) film and Au nanostructures is increasing in many fields including opto-electronics, photovoltaics, MEMS devices, diagnostics, bio-molecular sensors, spectro-/microscopic surfaces and probes. In this study, a novel continuous flow electroless (CF-EL) Au plating method is developed to fabricate uniform Au thin films in ambient condition. The enhanced local mass transfer rate and continuous deposition resulting from CF-EL plating improved physical uniformity of deposited Au films and thermally transformed nanoparticles (NPs). Au films and NPs exhibited improved optical photoluminescence (PL) and surface plasmon resonance (SPR), respectively, relative to batch immersion EL (BI-EL) plating. Suggested mass transfer models of Au mole deposition are consistent with optical feature of CF-EL and BI-EL films. The prototype CF-EL plating system is upgraded an automated scalable CF-EL plating system with real-time transmission UV-vis (T-UV) spectroscopy which provides the advantage of CF-EL plating, such as more uniform surface morphology, and overcomes the disadvantages of conventional EL plating, such as no continuous process and low deposition rate, using continuous process and controllable deposition rate. Throughout this work, dynamic morphological and chemical transitions during redox-driven self-assembly of Ag and Au film on silica surfaces under kinetic and equilibrium conditions are distinguished by correlating real-time T-UV spectroscopy with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements. The characterization suggests that four previously unrecognized time-dependent physicochemical regimes occur during consecutive EL deposition of silver (Ag) and Au onto tin-sensitized silica surfaces: self-limiting Ag activation; transitory Ag NP formation; transitional Au-Ag alloy formation during galvanic replacement of Ag by Au; and uniform morphology formation under

Semi-automated potentiometric titration method for uranium characterization

Energy Technology Data Exchange (ETDEWEB)

Cristiano, B.F.G., E-mail: barbara@ird.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Instituto de Radioprotecao e Dosimetria (IRD), Avenida Salvador Allende s/n Recreio dos Bandeirantes, PO Box 37750, Rio de Janeiro, 22780-160 RJ (Brazil); Delgado, J.U.; Silva, J.W.S. da; Barros, P.D. de; Araujo, R.M.S. de [Comissao Nacional de Energia Nuclear (CNEN), Instituto de Radioprotecao e Dosimetria (IRD), Avenida Salvador Allende s/n Recreio dos Bandeirantes, PO Box 37750, Rio de Janeiro, 22780-160 RJ (Brazil); Lopes, R.T. [Programa de Engenharia Nuclear (PEN/COPPE), Universidade Federal do Rio de Janeiro (UFRJ), Ilha do Fundao, PO Box 68509, Rio de Janeiro, 21945-970 RJ (Brazil)

2012-07-15

The manual version of the potentiometric titration method has been used for certification and characterization of uranium compounds. In order to reduce the analysis time and the influence of the analyst, a semi-automatic version of the method was developed in the Brazilian Nuclear Energy Commission. The method was applied with traceability assured by using a potassium dichromate primary standard. The combined standard uncertainty in determining the total concentration of uranium was around 0.01%, which is suitable for uranium characterization. - Highlights: Black-Right-Pointing-Pointer We developed a semi-automatic version of potentiometric titration method. Black-Right-Pointing-Pointer The method is used for certification and characterization of uranium compounds. Black-Right-Pointing-Pointer The traceability of the method was assured by a K{sub 2}Cr{sub 2}O{sub 7} primary standard. Black-Right-Pointing-Pointer The results of U{sub 3}O{sub 8} reference material analyzed was consistent with certified value. Black-Right-Pointing-Pointer The uncertainty obtained, near 0.01%, is useful for characterization purposes.

NEXAFS characterization of DNA components and molecular-orientation of surface-bound DNA oligomers

International Nuclear Information System (INIS)

Samuel, Newton T.; Lee, C.-Y.; Gamble, Lara J.; Fischer, Daniel A.; Castner, David G.

2006-01-01

Single stranded DNA oligomers (ssDNA) immobilized onto solid surfaces forms the basis for several biotechnological applications such as DNA microarrays, affinity separations, and biosensors. Surface structure of Surface-bound oligomers is expected to significantly influence their biological activity and interactions with the environment. In this study near-edge X-ray absorption fine structure spectroscopy (NEXAFS) is used to characterize the components of DNA (nucleobases, nucleotides and nucleosides) and the orientation information of surface-bound ssDNA. The K-edges of carbon, nitrogen and oxygen have spectra with features that are characteristic of the different chemical species present in the nucleobases of DNA. The effect of addition of the DNA sugar and phosphate components on the NEXAFS K-edge spectra was also investigated. The polarization-dependent nitrogen K-edge NEXAFS data show significant changes for different orientations of surface bound ssDNA. These results establish NEXAFS as a powerful technique for chemical and structural characterization of surface-bound DNA oligomers

Characterization of the Deep Water Surface Wave Variability in the California Current Region

Science.gov (United States)

Villas Bôas, Ana B.; Gille, Sarah T.; Mazloff, Matthew R.; Cornuelle, Bruce D.

2017-11-01

Surface waves are crucial for the dynamics of the upper ocean not only because they mediate exchanges of momentum, heat, energy, and gases between the ocean and the atmosphere, but also because they determine the sea state. The surface wave field in a given region is set by the combination of local and remote forcing. The present work characterizes the seasonal variability of the deep water surface wave field in the California Current region, as retrieved from over two decades of satellite altimetry data combined with wave buoys and wave model hindcast (WaveWatch III). In particular, the extent to which the local wind modulates the variability of the significant wave height, peak period, and peak direction is assessed. During spring/summer, regional-scale wind events of up to 10 m/s are the dominant forcing for waves off the California coast, leading to relatively short-period waves (8-10 s) that come predominantly from the north-northwest. The wave climatology throughout the California Current region shows average significant wave heights exceeding 2 m during most of the year, which may have implications for the planning and retrieval methods of the Surface Water and Ocean Topography (SWOT) satellite mission.

Nano-objects as biomaterials: immense opportunities, significant challenges and the important use of surface analytical methods

Energy Technology Data Exchange (ETDEWEB)

Baer, Donald R.; Shutthanandan, Vaithiyalingam

2017-05-30

Nano-sized objects are increasingly important as biomaterials and their surfaces play critical roles in determining their beneficial or deleterious behaviors in biological systems. Important characteristics of nanomaterials that impact their application in many areas are described with a strong focus on the importance of particle surfaces and surface characterization. Understanding aspects of the inherent nature of nano-objects and the important role that surfaces play in these applications is a universal need for any research or product development using such materials in biological applications. The role of surface analysis methods in collecting critical information about the nature of particle surfaces and physicochemical properties of nano-objects is described along with the importance of including sample history and analysis results in a record of provenance information regarding specific batches of nano-objects.

Repercussion of noni mouthwash on surface characterization of Nickel-Titanium archwire

Directory of Open Access Journals (Sweden)

Dhivya Dilipkumar

2017-01-01

Full Text Available Objective: Maintaining oral hygiene is very important during orthodontic therapy mouthwashes are prescribed as an adjunct to improve patient's oral hygiene. Commercially available mouthwashes e.g. Chlorhexidine, Listerine, fluoride containing mouthwashes have shown to alter the surface characteristics of orthodontic wires. Hence the purpose of the study was to evaluate the effect of Noni mouthwash on surface quality and compositional changes of Nickel Titanium orthodontic wires. Materials and Methods: In this in vitro study pre-formed 0.014 inch NiTi arch wire was used. The study comprised of two samples, one control and one test sample which were 25mm in length. Control sample was stored at room temperature without any manipulation while test sample was immersed in Noni mouthwash solution for 1.5 hours, after which the test specimen was removed from the mouthwash solution and rinsed with distilled water. Both control and test samples were sent for scanning electron microscopy analysis, to qualitatively characterize the topography of the wire surface. Electron dispersion spectrum analysis was done to evaluate the various components of both the wires. Results: No significant difference in the average surface roughness for both wire samples was observed. There was no significant difference seen in the composition of wire after immersion in Noni mouthwash. Conclusion: Noni mouthwash did not have significant influence on the surface roughness or altered the composition of the Ni-Ti wire. Hence Noni mouthwash may be prescribed as a natural, non-destructive prophylactic agent for orthodontic patients.

Surface characterization, hemo- and cytocompatibility of segmented poly(dimethylsiloxane-based polyurethanes

Directory of Open Access Journals (Sweden)

Pergal Marija V.

2014-01-01

Full Text Available Segmented polyurethanes based on poly(dimethylsiloxane, currently used for biomedical applications, have sub-optimal biocompatibility which reduces their efficacy. Improving the endothelial cell attachment and blood-contacting properties of PDMS-based copolymers would substantially improve their clinical applications. We have studied the surface properties and in vitro biocompatibility of two series of segmented poly(urethane-dimethylsiloxanes (SPU-PDMS based on hydroxypropyl- and hydroxyethoxypropyl- terminated PDMS with potential applications in blood-contacting medical devices. SPU-PDMS copolymers were characterized by contact angle measurements, surface free energy determination (calculated using the van Oss-Chaudhury-Good and Owens-Wendt methods, and atomic force microscopy. The biocompatibility of copolymers was evaluated using an endothelial EA.hy926 cell line by direct contact assay, before and after pre-treatment of copolymers with multicomponent protein mixture, as well as by a competitive blood-protein adsorption assay. The obtained results suggested good blood compatibility of synthesized copolymers. All copolymers exhibited good resistance to fibrinogen adsorption and all favored albumin adsorption. Copolymers based on hydroxyethoxypropyl-PDMS had lower hydrophobicity, higher surface free energy, and better microphase separation in comparison with hydroxypropyl-PDMS-based copolymers, which promoted better endothelial cell attachment and growth on the surface of these polymers as compared to hydroxypropyl-PDMS-based copolymers. The results showed that SPU-PDMS copolymers display good surface properties, depending on the type of soft PDMS segments, which can be tailored for biomedical application requirements such as biomedical devices for short- and long-term uses. [Projekat Ministarstva nauke Republike Srbije, br. 172062

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.

A volume-based method for denoising on curved surfaces

KAUST Repository

Biddle, Harry; von Glehn, Ingrid; Macdonald, Colin B.; Marz, Thomas

2013-01-01

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.

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.

Estimating surface acoustic impedance with the inverse method.

Science.gov (United States)

Piechowicz, Janusz

2011-01-01

Sound field parameters are predicted with numerical methods in sound control systems, in acoustic designs of building and in sound field simulations. Those methods define the acoustic properties of surfaces, such as sound absorption coefficients or acoustic impedance, to determine boundary conditions. Several in situ measurement techniques were developed; one of them uses 2 microphones to measure direct and reflected sound over a planar test surface. Another approach is used in the inverse boundary elements method, in which estimating acoustic impedance of a surface is expressed as an inverse boundary problem. The boundary values can be found from multipoint sound pressure measurements in the interior of a room. This method can be applied to arbitrarily-shaped surfaces. This investigation is part of a research programme on using inverse methods in industrial room acoustics.

Global characterization of surface soil moisture drydowns

Science.gov (United States)

McColl, Kaighin A.; Wang, Wei; Peng, Bin; Akbar, Ruzbeh; Short Gianotti, Daniel J.; Lu, Hui; Pan, Ming; Entekhabi, Dara

2017-04-01

Loss terms in the land water budget (including drainage, runoff, and evapotranspiration) are encoded in the shape of soil moisture "drydowns": the soil moisture time series directly following a precipitation event, during which the infiltration input is zero. The rate at which drydowns occur—here characterized by the exponential decay time scale τ—is directly related to the shape of the loss function and is a key characteristic of global weather and climate models. In this study, we use 1 year of surface soil moisture observations from NASA's Soil Moisture Active Passive mission to characterize τ globally. Consistent with physical reasoning, the observations show that τ is lower in regions with sandier soils, and in regions that are more arid. To our knowledge, these are the first global estimates of τ—based on observations alone—at scales relevant to weather and climate models.

Characterization of a complex near-surface structure using well logging and passive seismic measurements

Science.gov (United States)

Benjumea, Beatriz; Macau, Albert; Gabàs, Anna; Figueras, Sara

2016-04-01

We combine geophysical well logging and passive seismic measurements to characterize the near-surface geology of an area located in Hontomin, Burgos (Spain). This area has some near-surface challenges for a geophysical study. The irregular topography is characterized by limestone outcrops and unconsolidated sediments areas. Additionally, the near-surface geology includes an upper layer of pure limestones overlying marly limestones and marls (Upper Cretaceous). These materials lie on top of Low Cretaceous siliciclastic sediments (sandstones, clays, gravels). In any case, a layer with reduced velocity is expected. The geophysical data sets used in this study include sonic and gamma-ray logs at two boreholes and passive seismic measurements: three arrays and 224 seismic stations for applying the horizontal-to-vertical amplitude spectra ratio method (H/V). Well-logging data define two significant changes in the P-wave-velocity log within the Upper Cretaceous layer and one more at the Upper to Lower Cretaceous contact. This technique has also been used for refining the geological interpretation. The passive seismic measurements provide a map of sediment thickness with a maximum of around 40 m and shear-wave velocity profiles from the array technique. A comparison between seismic velocity coming from well logging and array measurements defines the resolution limits of the passive seismic techniques and helps it to be interpreted. This study shows how these low-cost techniques can provide useful information about near-surface complexity that could be used for designing a geophysical field survey or for seismic processing steps such as statics or imaging.

One-step method for the fabrication of superhydrophobic surface on magnesium alloy and its corrosion protection, antifouling performance

International Nuclear Information System (INIS)

Zhao, Lin; Liu, Qi; Gao, Rui; Wang, Jun; Yang, Wanlu; Liu, Lianhe

2014-01-01

Highlights: •The myristic acid iron superhydrophobic surface was formatted on AZ31. •Two procedures to build a super-hydrophobic were simplified to one step. •The superhydrophobic surface shows good anticorrosion, antifouling properties. •We report a new approach for the superhydrophobic surface protection on AZ31. -- Abstract: Inspired by the lotus leaf, various methods to fabricate artificial superhydrophobic surfaces have been developed. Our purpose is to create a simple, one-step and environment-friendly method to construct a superhydrophobic surface on a magnesium alloy substrate. The substrate was immersed in a solution containing ferric chloride (FeCl 3 ·6H 2 O), deionized water, tetradecanoic acid (CH 3 (CH 2 ) 12 COOH) and ethanol. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared (FT-IR) were employed to characterize the substrate surface. The obtained surface showed a micron rough structure, a high contact angle (CA) of 165° ± 2° and desirable corrosion protection and antifouling properties

Surface chemical and biological characterization of flax fabrics modified with silver nanoparticles for biomedical applications

International Nuclear Information System (INIS)

Paladini, F.; Picca, R.A.; Sportelli, M.C.; Cioffi, N.; Sannino, A.; Pollini, M.

2015-01-01

Silver nanophases are increasingly used as effective antibacterial agent for biomedical applications and wound healing. This work aims to investigate the surface chemical composition and biological properties of silver nanoparticle-modified flax substrates. Silver coatings were deposited on textiles through the in situ photo-reduction of a silver solution, by means of a large-scale apparatus. The silver-coated materials were characterized through X-ray Photoelectron Spectroscopy (XPS), to assess the surface elemental composition of the coatings, and the chemical speciation of both the substrate and the antibacterial nanophases. A detailed investigation of XPS high resolution regions outlined that silver is mainly present on nanophases' surface as Ag 2 O. Scanning electron microscopy and energy dispersive X-ray spectroscopy were also carried out, in order to visualize the distribution of silver particles on the fibers. The materials were also characterized from a biological point of view in terms of antibacterial capability and cytotoxicity. Agar diffusion tests and bacterial enumeration tests were performed on Gram positive and Gram negative bacteria, namely Staphylococcus aureus and Escherichia coli. In vitro cytotoxicity tests were performed through the extract method on murine fibroblasts in order to verify if the presence of the silver coating affected the cellular viability and proliferation. Durability of the coating was also assessed, thus confirming the successful scaling up of the process, which will be therefore available for large-scale production. - Highlights: • Silver nanophases are increasingly used as effective antibacterial agent for biomedical applications. • Silver coatings were deposited on textiles through the in situ photo-reduction of a silver solution. • Flax fabrics were characterized from a biological and surface chemical point of view. • Scaling up of the process was confirmed

Identification and characterization of the surface proteins of Clostridium difficile

International Nuclear Information System (INIS)

Dailey, D.C.

1988-01-01

Several clostridial proteins were detected on the clostridial cell surface by sensitive radioiodination techniques. Two major proteins and six minor proteins comprised the radioiodinated proteins on the clostridial cell surface. Cellular fractionation of surface radiolabeled C. difficile determined that the radioiodinated proteins were found in the cell wall fraction of C. difficile and surprisingly were also present in the clostridial membrane. Furthermore, an interesting phenomenon of disulfide-crosslinking of the cell surface proteins of C. difficile was observed. Disulfide-linked protein complexes were found in both the membrane and cell wall fractions. In addition, the cell surface proteins of C. difficile were found to be released into the culture medium. In attempts to further characterize the clostridial proteins recombinant DNA techniques were employed. In addition, the role of the clostridial cell surface proteins in the interactions of C. difficile with human PMNs was also investigated

Methods for characterizing convective cryoprobe heat transfer in ultrasound gel phantoms.

Science.gov (United States)

Etheridge, Michael L; Choi, Jeunghwan; Ramadhyani, Satish; Bischof, John C

2013-02-01

While cryosurgery has proven capable in treating of a variety of conditions, it has met with some resistance among physicians, in part due to shortcomings in the ability to predict treatment outcomes. Here we attempt to address several key issues related to predictive modeling by demonstrating methods for accurately characterizing heat transfer from cryoprobes, report temperature dependent thermal properties for ultrasound gel (a convenient tissue phantom) down to cryogenic temperatures, and demonstrate the ability of convective exchange heat transfer boundary conditions to accurately describe freezing in the case of single and multiple interacting cryoprobe(s). Temperature dependent changes in the specific heat and thermal conductivity for ultrasound gel are reported down to -150 °C for the first time here and these data were used to accurately describe freezing in ultrasound gel in subsequent modeling. Freezing around a single and two interacting cryoprobe(s) was characterized in the ultrasound gel phantom by mapping the temperature in and around the "iceball" with carefully placed thermocouple arrays. These experimental data were fit with finite-element modeling in COMSOL Multiphysics, which was used to investigate the sensitivity and effectiveness of convective boundary conditions in describing heat transfer from the cryoprobes. Heat transfer at the probe tip was described in terms of a convective coefficient and the cryogen temperature. While model accuracy depended strongly on spatial (i.e., along the exchange surface) variation in the convective coefficient, it was much less sensitive to spatial and transient variations in the cryogen temperature parameter. The optimized fit, convective exchange conditions for the single-probe case also provided close agreement with the experimental data for the case of two interacting cryoprobes, suggesting that this basic characterization and modeling approach can be extended to accurately describe more complicated

Food powders flowability characterization: theory, methods, and applications.

Science.gov (United States)

Juliano, Pablo; Barbosa-Cánovas, Gustavo V

2010-01-01

Characterization of food powders flowability is required for predicting powder flow from hoppers in small-scale systems such as vending machines or at the industrial scale from storage silos or bins dispensing into powder mixing systems or packaging machines. This review covers conventional and new methods used to measure flowability in food powders. The method developed by Jenike (1964) for determining hopper outlet diameter and hopper angle has become a standard for the design of bins and is regarded as a standard method to characterize flowability. Moreover, there are a number of shear cells that can be used to determine failure properties defined by Jenike's theory. Other classic methods (compression, angle of repose) and nonconventional methods (Hall flowmeter, Johanson Indicizer, Hosokawa powder tester, tensile strength tester, powder rheometer), used mainly for the characterization of food powder cohesiveness, are described. The effect of some factors preventing flow, such as water content, temperature, time consolidation, particle composition and size distribution, is summarized for the characterization of specific food powders with conventional and other methods. Whereas time-consuming standard methods established for hopper design provide flow properties, there is yet little comparative evidence demonstrating that other rapid methods may provide similar flow prediction.

Surface characterization

Science.gov (United States)

Mandla A. Tshabalala

2005-01-01

Surface properties of wood play an important role when wood is used or processed into different commodities such as siding, joinery, textiles, paper, sorption media or wood composites. Thus, for example, the quality and durability of a wood coating are determined by the surface properties of the wood and the coating. The same is true for wood composites, as the...

Surface analysis of Dicrocoelium dendriticum. The molecular characterization of exosomes reveals the presence of miRNAs.

Science.gov (United States)

Bernal, Dolores; Trelis, Maria; Montaner, Sergio; Cantalapiedra, Fernando; Galiano, Alicia; Hackenberg, Michael; Marcilla, Antonio

2014-06-13

With the aim of characterizing the molecules involved in the interaction of Dicrocoelium dendriticum adults and the host, we have performed proteomic analyses of the external surface of the parasite using the currently available datasets including the transcriptome of the related species Echinostoma caproni. We have identified 182 parasite proteins on the outermost surface of D. dendriticum. The presence of exosome-like vesicles in the ESP of D. dendriticum and their components has also been characterized. Using proteomic approaches, we have characterized 84 proteins in these vesicles. Interestingly, we have detected miRNA in D. dendriticum exosomes, thus representing the first report of miRNA in helminth exosomes. In order to identify potential targets for intervention against parasitic helminths, we have analyzed the surface of the parasitic helminth Dicrocoelium dendriticum. Along with the proteomic analyses of the outermost layer of the parasite, our work describes the molecular characterization of the exosomes of D. dendriticum. Our proteomic data confirm the improvement of protein identification from "non-model organisms" like helminths, when using different search engines against a combination of available databases. In addition, this work represents the first report of miRNAs in parasitic helminth exosomes. These vesicles can pack specific proteins and RNAs providing stability and resistance to RNAse digestion in body fluids, and provide a way to regulate host-parasite interplay. The present data should provide a solid foundation for the development of novel methods to control this non-model organism and related parasites. This article is part of a Special Issue entitled: Proteomics of non-model organisms. Copyright © 2014 Elsevier B.V. All rights reserved.

METHODS FOR THE REPRESENTATION OF THE HELICOIDAL SURFACE

Directory of Open Access Journals (Sweden)

SCURTU Liviu-Iacob

2017-05-01

Full Text Available In this paper there are presented the graphical methods to determine the parameters of an helicoidal stairs. The first part of this paper shows the used methods to generate the helicoidal curves using descriptive geometry methods. It has represented the state of the art of the generation of a helical surface studies. The second part of this study shows the helical stairs surface representation using descriptive geometry methods. For the representation of the helicoidal stairs are used two projections, the front and top view. A method of the stairs representation is solved using CAD modelling dedicated software. Following the helical surface representation in both methods, has been achieved a comparative study by using two representation methods. Conclusions about these two representation methods are presented in the end of this paper.

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.)

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.

Defects at oxide surfaces

CERN Document Server

Thornton, Geoff

2015-01-01

This book presents the basics and characterization of defects at oxide surfaces. It provides a state-of-the-art review of the field, containing information to the various types of surface defects, describes analytical methods to study defects, their chemical activity and the catalytic reactivity of oxides. Numerical simulations of defective structures complete the picture developed. Defects on planar surfaces form the focus of much of the book, although the investigation of powder samples also form an important part. The experimental study of planar surfaces opens the possibility of applying the large armoury of techniques that have been developed over the last half-century to study surfaces in ultra-high vacuum. This enables the acquisition of atomic level data under well-controlled conditions, providing a stringent test of theoretical methods. The latter can then be more reliably applied to systems such as nanoparticles for which accurate methods of characterization of structure and electronic properties ha...

Surface and electrochemical characterization of electrodeposited PtRu alloys

Science.gov (United States)

Richarz, Frank; Wohlmann, Bernd; Vogel, Ulrich; Hoffschulz, Henning; Wandelt, Klaus

1995-07-01

PtRu alloys of different compositions were electrodeposited on Au. Twelve alloys between 0% and 100% Pt were characterized with surface sensitive spectroscopies (XPS, LEIS) after transfer from an electrochemical cell to an ultra high vaccum chamber without contact to air. The composition of the thus prepared alloys showed a linear dependence on the concentrations of the deposition solution, but was Pt-enriched both in the bulk and (even more so) at the surface. During the electrochemical reduction of the metal cations, sulfur from the supporting electrolyte 1N H 2SO 4 was found to be incorporated into the electrodes. Cyclic voltammetry was used for the determination of the electrocatalytic activity of the electrodes for the oxidation of carbon monoxide. The highest activity for this oxidation as measured by the (peak) potential of the CO oxidation cyclovoltammograms was found for a surface concentration of ˜ 50%Pt. The asymmetry of this "activity curve" (oxidation potential versus Pt surface concentration) is tentatively explained in terms of a surface structural phase separation.

3D, chemical and electrochemical characterization of blasted TI6Al4V surfaces: Its influence on the corrosion behaviour

International Nuclear Information System (INIS)

Barranco, V.; Escudero, M.L.; Garcia-Alonso, M.C.

2007-01-01

The blasting process to increase the roughness of the surface of metallic biomaterials is widely used. As a consequence, one can produce a renewed surface with different topography and chemical composition compared to the original one, which can alter the general corrosion behaviour of the samples. With this idea, the aim of this work is not only the topographical and compositional characterization of blasted surfaces of Ti6Al4V alloy but mainly its influence on the corrosion behaviour of these modified surfaces. The surfaces of Ti6Al4V alloys were blasted with SiO 2 /ZrO 2 and Al 2 O 3 particles of different size in order to obtain different roughnesses. To carry out the microstructural and topographical characterization of the blasted surfaces, the scanning electron microscopy (SEM) coupled with an energy dispersive X-ray (EDX), the contact profilometry method and the 3D characterization by means of stereo-Fe-SEM have been used. By means of stereo-Fe-SEM, the roughness and the real surface area of the rough surfaces have been calculated. The microstructural, topographical and compositional results have been correlated with the corrosion behaviour of the samples immersed in Hank's solution and studied by means of electrochemical impedance spectroscopy (EIS). The blasting process alters topographical and chemically the surface of the samples. These modifications induce to an increase in the capacitance values of the roughened samples due to the prevalence of the effect of electrochemically active areas of Ti6Al4V surface over the effect of the presence of Al 2 O 3 and ZrO 2 particles on the blasted surfaces. However, the general corrosion behaviour of the samples is not drastically changed

Surface and Electrical Characterization of Conjugated Molecular Wires

Science.gov (United States)

Demissie, Abel Tesfahun

This thesis describes the surface and electrical characterization of ultrathin organic films and interfaces. These films were synthesized on the surface of gold by utilizing layer by layer synthesis via imine condensation. Film growth by imine click (condensation) chemistry is particularly useful for molecular electronics experiments because it provides a convenient means to obtain and extend ?-conjugation in the growth direction. However, in the context of film growth from a solid substrate, the reaction yield per step has not been characterized previously, though it is critically important. To address these issues, my research focused on a comprehensive characterization of oligophenyleneimine (OPI) wires via Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), reflection-absorption infrared spectroscopy (RAIRS), and cyclic voltammetry (CV). In addition, we had the unique opportunity of developing the first of its kind implementation of nuclear reaction analysis (NRA) to probe the intensity of carbon atoms after each addition step. Overall the combination of various techniques indicated that film growth proceeds in a quantitative manner. Furthermore, the NRA experiment was optimized to measure the carbon content in self-assembled monolayers of alkyl thiols. The results indicated well-resolved coverage values for ultrathin films with consecutive steps of 2 carbon atoms per molecule. Another fundamental problem in molecular electronics is the vast discrepancy in the values of measured resistance per molecule between small and large area molecular junctions. In collaboration with researchers at the National University of Singapore, we addressed these issues by comparing the electrical properties of OPI wires with the eutectic gallium indium alloy (EGaIn) junction (1000 mum2), and conducting probe atomic force microscopy (CP-AFM) junction (50 nm2). Our results showed that intensive (i.e., area

Definition of a critical confining zone using surface geophysical methods

International Nuclear Information System (INIS)

Eddy-Dilek, C.A.; Hoekstra, P.; Harthill, N.; Blohm, M.; Phillips, D.R.

1996-01-01

Definition of the hydrogeologic framework in layered sediments of fluvial and deltaic origin is a difficult challenge for environmental characterization and remediation programs due to the lithologic and stratigraphic heterogeneities inherent in these settings. These heterogeneties often control contaminant transport and the effectiveness of remediation alternatives, Surface geophysical surveys can be cost-effective methods for characterization, but individual methods have inherent limitations in resolution and sensitivity. A synergistic approach, utilizing two geophysical survey methods was applied, to define and examine the nature and extent of a deep confining zone of regulatory importance, the Crouch Branch Confining Unit, in Coastal Plain sediments at the Savannah River Site. TDEM accurately maps the overall conductance (product of thickness and electrical conductivity) of a confining zone clay facies; from variation in conductance, changes in lithology of the conforming zone can be inferred. Shear wave seismic reflection surveys map the depth to the clay layers, and the clay layer thickness, but provides little information on the lithologic nature of the confining zone. Integrated interpretation of the combined data set (including all available borehole logs) allows for delineation of the lateral and vertical extent of clay-dominated zones, sand-dominated zones, key stratigraphic horizons, and erosional features associated with unconformities. This approach has resulted in the collection of critical information that will be used to optimize remedial system design, representing a significant cost savings to environmental restoration programs at the Savannah River Site

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

Site Classification using Multichannel Channel Analysis of Surface Wave (MASW) method on Soft and Hard Ground

Science.gov (United States)

Ashraf, M. A. M.; Kumar, N. S.; Yusoh, R.; Hazreek, Z. A. M.; Aziman, M.

2018-04-01

Site classification utilizing average shear wave velocity (Vs(30) up to 30 meters depth is a typical parameter. Numerous geophysical methods have been proposed for estimation of shear wave velocity by utilizing assortment of testing configuration, processing method, and inversion algorithm. Multichannel Analysis of Surface Wave (MASW) method is been rehearsed by numerous specialist and professional to geotechnical engineering for local site characterization and classification. This study aims to determine the site classification on soft and hard ground using MASW method. The subsurface classification was made utilizing National Earthquake Hazards Reduction Program (NERHP) and international Building Code (IBC) classification. Two sites are chosen to acquire the shear wave velocity which is in the state of Pulau Pinang for soft soil and Perlis for hard rock. Results recommend that MASW technique can be utilized to spatially calculate the distribution of shear wave velocity (Vs(30)) in soil and rock to characterize areas.

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 ...

Characterizing the surface charge of synthetic nanomembranes by the streaming potential method

OpenAIRE

Datta, Subhra; Conlisk, A. T.; Kanani, Dharmesh M.; Zydney, Andrew L.; Fissell, William H.; Roy, Shuvo

2010-01-01

The inference of the surface charge of polyethylene glycol (PEG)-coated and uncoated silicon membranes with nanoscale pore sizes from streaming potential measurements in the presence of finite electric double layer (EDL) effects is studied theoretically and experimentally. The developed theoretical model for inferring the pore wall surface charge density from streaming potential measurements is applicable to arbitrary pore cross-sectional shapes and accounts for the effect of finite salt conc...

Characterization of Modified and Polymer Coated Alumina Surfaces by Infrared Spectroscopy

Directory of Open Access Journals (Sweden)

Ashraf Yehia El-Naggar

2013-01-01

Full Text Available The prepared, modified, and coated alumina surfaces were characterized by infrared spectroscopy (FTIR to investigate the surface properties of the individual and double modified samples. FTIR helps in reporting the changes occurred in hydroxyl groups as well as the structure changes as a result of thermal treating, hydrothermal treating, silylation treating, alkali metal treating, coating, and bonding with polymer. FTIR spectroscopy represents the strength and abundance of surface acidic OH which determine the adsorption properties of polar and nonpolar sorbents. Generally, all treated samples exhibit decrease of OH groups compared with those of parent ones producing alumina surfaces of different adsorptive powers.

Application of geophysical methods for fracture characterization

International Nuclear Information System (INIS)

Lee, K.H.; Majer, E.L.; McEvilly, T.V.; California Univ., Berkeley, CA; Morrison, H.F.; California Univ., Berkeley, CA

1990-01-01

One of the most crucial needs in the design and implementation of an underground waste isolation facility is a reliable method for the detection and characterization of fractures in zones away from boreholes or subsurface workings. Geophysical methods may represent a solution to this problem. If fractures represent anomalies in the elastic properties or conductive properties of the rocks, then the seismic and electrical techniques may be useful in detecting and characterizing fracture properties. 7 refs., 3 figs

Oromucosal film preparations: classification and characterization methods.

Science.gov (United States)

Preis, Maren; Woertz, Christina; Kleinebudde, Peter; Breitkreutz, Jörg

2013-09-01

Recently, the regulatory authorities have enlarged the variety of 'oromucosal preparations' by buccal films and orodispersible films. Various film preparations have entered the market and pharmacopoeias. Due to the novelty of the official monographs, no standardized characterization methods and quality specifications are included. This review reports the methods of choice to characterize oromucosal film preparations with respect to biorelevant characterization and quality control. Commonly used dissolution tests for other dosage forms are not transferable for films in all cases. Alternatives and guidance on decision, which methods are favorable for film preparations are discussed. Furthermore, issues about requirements for film dosage forms are reflected. Oromucosal film preparations offer a wide spectrum of opportunities. There are a lot of suggestions in the literature on how to control the quality of these innovative products, but no standardized tests are available. Regulatory authorities need to define the standards and quality requirements more precisely.

Surface modification and characterization of magnesium hydroxide sulfate hydrate nanowhiskers

Energy Technology Data Exchange (ETDEWEB)

Gao Chuanhui [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); Li Xianguo, E-mail: chuanhuigao@foxmail.com [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); Feng Lijuan; Lu Shaoyan; Liu Jinyan [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China)

2010-03-01

In order to enhance the compatibility with plastic polymers, magnesium hydroxide sulfate hydrate (MHSH) nanowhiskers were modified through grafting methyl methacrylate (MMA) on the surface of the nanowhiskers by emulsion polymerization. The influences of the reaction time, MMA monomer content, adding speed of monomer and the reaction temperature on the grafting ratio were investigated. Thermogravimetry (TG), Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray (EDX) spectroscopy and surface contact angle measurement were used to characterize the effect of surface modification. The results showed that the MHSH nanowhiskers were uniformly coated by polymethyl methacrylate (PMMA), and a well-defined core-shell hybrid structure of MHSH/PMMA was obtained. The surface contact angle of the hybrid whiskers increased to 87.32 deg. from 12.71 deg. and the whiskers surface was changed from hydrophilic to lipophilic.

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

Production and characterization of surface-active compounds from Gordonia amicalis

Directory of Open Access Journals (Sweden)

Ani Beatriz Jackisch-Matsuura

2014-02-01

Full Text Available Two methods were used to make crude preparations of surface-active compounds (SACs produced by Gordonia amicalis grown on the medium containing 1% diesel oil. Using a 2:1 (v/v solution of chloroform:methanol for extraction, Type I SACs were isolated and shown to produce oil in water (O/W emulsions. Type II SACs were isolated by precipitation with ammonium sulfate and produced predominantly water in oil emulsions (W/O. The crude Type I and II preparations were able to produce a significant reduction in the surface tension of water; however, the crude Type II preparation had 10-25 fold higher emulsification activity than the Type I preparation. Both SAC preparations were analyzed by the TLC and each produced two distinct bands with Rf 0.44 and 0.62 and Rf 0.52 and 0.62, respectively. The partially purified SACs were characterized by the ESI(+-MS, FT-IR and NMR. In each one of these fractions, a mixture of 10 oligomers was found consisting of a series of compounds, with masses from 502 to 899, differing in molecular mass by a repeating unit of 44 Daltons. The mass spectra of these compounds did not appear to match other known biosurfactants and could represent a novel class of these compounds.

Characterization of nuclear fuel using immersion and method of penetration (MPI)

International Nuclear Information System (INIS)

Faeda, K. C. M.; Lameiras, F.S.; Ferraz, W.B.; Machado, G.C.

2011-01-01

The characterization of nuclear fuel is of great importance and aims to minimize the effects related to burning and the temperature in the fuel, so that the stability of the fuel during the time of his stay in the reactor core. The method of penetration and use the boost immersion with vacuum impregnation to measure density and open porosity of ceramic materials. It is non-destructive if the liquid impregnation can be removed from the sample. The impregnation requires the use of a liquid with low surface tension and small variation of surface tension with temperature. The xylene due its large industrial employment has been widely used for this purpose. However, it presents serious problems of toxicity. In this work, comparable studies of xylene with water + detergent to measure density and porosity in alumina pellets. The atmospheric pressure, temperature and humidity were monitored during the measurements and considered as covariates. (author)

Apparatus and procedure to characterize the surface quality of conductors by measuring the rate of cathode emission as a function of surface electric field strength

Science.gov (United States)

Mestayer, Mac; Christo, Steve; Taylor, Mark

2014-10-21

A device and method for characterizing quality of a conducting surface. The device including a gaseous ionizing chamber having centrally located inside the chamber a conducting sample to be tested to which a negative potential is applied, a plurality of anode or "sense" wires spaced regularly about the central test wire, a plurality of "field wires" at a negative potential are spaced regularly around the sense, and a plurality of "guard wires" at a positive potential are spaced regularly around the field wires in the chamber. The method utilizing the device to measure emission currents from the conductor.

Characterization of the silicon nanopillar-surface filled and grafted with nanomaterials

International Nuclear Information System (INIS)

He, Yuan; Che, Xiangchen; Que, Long

2014-01-01

This paper reports the characterization of the silicon nanopillar-surface filled and grafted with nanomaterials. Usually a silicon nanopillar-surface contains nanopillars and air among them. The air is not a good medium to absorb and trap the incoming photons. In order to improve this capability, the air should be replaced with other material. To this end, copper sulfide–gold (CuS–Au) core–shell nanostructures and silver nanoplates are used as two representative substitutes for air among the nanopillars. Experiments find that the reflectance of the nanomaterial-coated nanopillar-surface can be reduced at least 50% compared to that of the bare nanopillar-surface. Different nanomaterial-coated nanopillar-surface can tune the optical reflectance and absorption profile, thereby trapping photons in different wavelength ranges. (paper)

Updating the 2001 National Land Cover Database Impervious Surface Products to 2006 using Landsat imagery change detection methods

Science.gov (United States)

Xian, George; Homer, Collin G.

2010-01-01

A prototype method was developed to update the U.S. Geological Survey (USGS) National Land Cover Database (NLCD) 2001 to a nominal date of 2006. NLCD 2001 is widely used as a baseline for national land cover and impervious cover conditions. To enable the updating of this database in an optimal manner, methods are designed to be accomplished by individual Landsat scene. Using conservative change thresholds based on land cover classes, areas of change and no-change were segregated from change vectors calculated from normalized Landsat scenes from 2001 and 2006. By sampling from NLCD 2001 impervious surface in unchanged areas, impervious surface predictions were estimated for changed areas within an urban extent defined by a companion land cover classification. Methods were developed and tested for national application across six study sites containing a variety of urban impervious surface. Results show the vast majority of impervious surface change associated with urban development was captured, with overall RMSE from 6.86 to 13.12% for these areas. Changes of urban development density were also evaluated by characterizing the categories of change by percentile for impervious surface. This prototype method provides a relatively low cost, flexible approach to generate updated impervious surface using NLCD 2001 as the baseline.

METHOD AND APPARATUS FOR CHARACTERIZATION OF A SOLAR CELL

DEFF Research Database (Denmark)

2017-01-01

; and estimating variations in the solar cell, thereby electrically characterizing the solar cell. The disclosure further relates to a solar cell characterization apparatus for characterization of a solar cell, comprising: a light source for generating an optical probe light; a modulation unit, configured...... to produce modulated probe light by modulating the optical probe light with a modulation frequency of between 100 kHz and 0 MHz; a light scanning unit for scanning the modulated probe light such that said modulated probe light is incident on at least a part of the surface of the solar cell; and a 1 signal...

Characterization of the solar climate in Malawi using NASA's surface ...

African Journals Online (AJOL)

user

Characterization of the solar climate in Malawi using. NASA's surface meteorology and solar energy. (SSE) model. Senganimalunje, T. C.1 and Tenthani, C. M. 2*. 1Malawi Bureau of Standards, Metrology Services Department, Box 946, Blantyre, Malawi. 2Physics and Biochemical Sciences Department, Malawi Polytechnic, ...

Adhesion of nitrile rubber to UV-assisted surface chemical modified PET fabric, part II: Interfacial characterization of MDI grafted PET

Energy Technology Data Exchange (ETDEWEB)

Razavizadeh, Mahmoud; Jamshidi, Masoud, E-mail: mjamshidi@iust.ac.ir

2016-08-30

Highlights: • In this research UV-irradiated PET fabric was chemically modified. • The fabric at first carboxylated under UV irradiation using glutaric anhydride, then it was grafted using isocyanate (i.e. MDI). • The surface of the fabric was characterized before and after each treating satge. • The composite samples were prepared and tested for T-Peel test. The surfaces of the fabrics were surface characterized to understand. - Abstract: Fiber to rubber adhesion is an important subject in rubber industry. It is well known that surface treatment (i.e. physical, mechanical and chemical) is an effective method to improve interfacial bonding of fibers and/or fabrics to rubbers. UV irradiation is an effective method which has been used to increase fabric-rubber interfacial interactions. In this research UV assisted chemical modification of PET fabrics was used to increase PET to nitrile rubber (NBR) adhesion. Nitrile rubber is a perfect selection as fuel and oil resistant rubber. However it has weak bonding to PET fabric. For this purpose PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was grafted on carboxylated PET. The chemical composition of the fabric before and after surface treatment was investigated by X-ray photoelectron spectroscopy (XPS). The sectional morphology of the experimental PET fibers and the interface between rubber compound and PET fabric was studied using scanning electron microscope (SEM). The morphology and structure of the product were analyzed by an energy dispersive X-ray spectrometer (EDX). FTIR-ATR and H NMR analysis were used to assess surface modifications on the PET irradiated fabrics.

Adhesion of nitrile rubber to UV-assisted surface chemical modified PET fabric, part II: Interfacial characterization of MDI grafted PET

International Nuclear Information System (INIS)

Razavizadeh, Mahmoud; Jamshidi, Masoud

2016-01-01

Highlights: • In this research UV-irradiated PET fabric was chemically modified. • The fabric at first carboxylated under UV irradiation using glutaric anhydride, then it was grafted using isocyanate (i.e. MDI). • The surface of the fabric was characterized before and after each treating satge. • The composite samples were prepared and tested for T-Peel test. The surfaces of the fabrics were surface characterized to understand. - Abstract: Fiber to rubber adhesion is an important subject in rubber industry. It is well known that surface treatment (i.e. physical, mechanical and chemical) is an effective method to improve interfacial bonding of fibers and/or fabrics to rubbers. UV irradiation is an effective method which has been used to increase fabric-rubber interfacial interactions. In this research UV assisted chemical modification of PET fabrics was used to increase PET to nitrile rubber (NBR) adhesion. Nitrile rubber is a perfect selection as fuel and oil resistant rubber. However it has weak bonding to PET fabric. For this purpose PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was grafted on carboxylated PET. The chemical composition of the fabric before and after surface treatment was investigated by X-ray photoelectron spectroscopy (XPS). The sectional morphology of the experimental PET fibers and the interface between rubber compound and PET fabric was studied using scanning electron microscope (SEM). The morphology and structure of the product were analyzed by an energy dispersive X-ray spectrometer (EDX). FTIR-ATR and H NMR analysis were used to assess surface modifications on the PET irradiated fabrics.

Preparation, characterization, and surface conductivity of nanocomposites with hollow graphitic carbon nanospheres as fillers in polymethylmethacrylate matrix

Science.gov (United States)

Zhang, Cheng; Gao, Qingshan; Zhou, Bing; Bhargava, Gaurang

2017-08-01

Hollow graphitized carbon nanosphere (CNS) materials with inner diameter of 20 to 50 nm and shell thickness of 10 15 nm were synthesized from the polymerization of resorcinol (R) and formaldehyde (F) in the presence of a well-characterized iron polymeric complex (IPC). The CNS with unique nanostructures was used to fabricate CNS-polymer composites by dispersing CNS as fillers in the polymer matrix. Aggregation of CNS in polymer composites is usually a challenging issue. In this work, we employed in situ polymerization method and melt-mixing method to fabricate CNS-polymethylmethacrylate (PMMA) composites and compared their difference in terms of CNS dispersion in the composites and surface electrical conductivity. Four probes technique was utilized to measure the surface electrical conductivity of the CNS-PMMA composites. The measurements on four points and four silver painted lines on the thin film of CNS-PMMA composites were compared. The in situ polymerization method was found more efficient for better CNS dispersion in PMMA matrix and lower percolation conductivity threshold compared to the melt-mixing method. The enhanced electrical conductivity for CNS-PMMA composites may be attributed to the stronger covalent CNS-PMMA bonding between the surface functional groups and the MMA moieties.

COLUROUTE : a mobile gonio-reflectometer to characterize the road surface photometry

OpenAIRE

MUZET, Valérie; PAUMIER, Jean Luc; GUILLARD, Yannick

2008-01-01

Designing a lighting installation involves accounting for site-specific geometric parameters and photometric characteristics of both the light sources and the road surface. The standard tool for characterizing road surface photometry is the reduced luminance coefficient table (or R-table), as defined in the 70's by the CIE. However, recent studies have shown that these tables are no longer representative. In this context, measuring road photometry is necessary for optimizing a lighting ins...

Preparation and Characterization of Ni Spines Grown on the Surface of Cubic Boron Nitride Grains by Electroplating Method

Science.gov (United States)

Gui, Yanghai; Zhao, Jianbo; Chen, Jingbo; Jiang, Yuanli

2016-01-01

Cubic boron nitride (cBN) is widely applied in cutting and grinding tools. cBN grains plated by pure Ni and Ni/SiC composite were produced under the same conditions from an additive-free nickel Watts type bath. The processed electroplating products were characterized by the techniques of scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermoanalysis (TG-DTA). Due to the presence of SiC particles, there are some additional nodules on the surface of Ni/SiC plated cBN compared with the pure Ni plated cBN. The unique morphology of Ni/SiC plated cBN should attain greater retention force in resin bond. Moreover, the coating weight of cBN grains could be controlled by regulating the plating time. cBN grains with 60% coating weight possess the optimum grinding performance due to their roughest and spiniest surface. In addition, Ni spines plated cBN grains show good thermal stability when temperature is lower than 464 °C. Therefore, the plated cBN grains are more stable and suitable for making resin bond abrasive tools below 225 °C. Finally, the formation mechanism of electroplating products is also discussed. PMID:28773283

Statistical methods for change-point detection in surface temperature records

Science.gov (United States)

Pintar, A. L.; Possolo, A.; Zhang, N. F.

2013-09-01

We describe several statistical methods to detect possible change-points in a time series of values of surface temperature measured at a meteorological station, and to assess the statistical significance of such changes, taking into account the natural variability of the measured values, and the autocorrelations between them. These methods serve to determine whether the record may suffer from biases unrelated to the climate signal, hence whether there may be a need for adjustments as considered by M. J. Menne and C. N. Williams (2009) "Homogenization of Temperature Series via Pairwise Comparisons", Journal of Climate 22 (7), 1700-1717. We also review methods to characterize patterns of seasonality (seasonal decomposition using monthly medians or robust local regression), and explain the role they play in the imputation of missing values, and in enabling robust decompositions of the measured values into a seasonal component, a possible climate signal, and a station-specific remainder. The methods for change-point detection that we describe include statistical process control, wavelet multi-resolution analysis, adaptive weights smoothing, and a Bayesian procedure, all of which are applicable to single station records.

Dynamic tunneling force microscopy for characterizing electronic trap states in non-conductive surfaces

Energy Technology Data Exchange (ETDEWEB)

Wang, R.; Williams, C. C., E-mail: clayton@physics.utah.edu [Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112 (United States)

2015-09-15

Dynamic tunneling force microscopy (DTFM) is a scanning probe technique for real space mapping and characterization of individual electronic trap states in non-conductive films with atomic scale spatial resolution. The method is based upon the quantum mechanical tunneling of a single electron back and forth between a metallic atomic force microscopy tip and individual trap states in completely non-conducting surface. This single electron shuttling is measured by detecting the electrostatic force induced on the probe tip at the shuttling frequency. In this paper, the physical basis for the DTFM method is unfolded through a physical model and a derivation of the dynamic tunneling signal as a function of several experimental parameters is shown. Experimental data are compared with the theoretical simulations, showing quantitative consistency and verifying the physical model used. The experimental system is described and representative imaging results are shown.

Extended volume and surface scatterometer for optical characterization of 3D-printed elements

Science.gov (United States)

Dannenberg, Florian; Uebeler, Denise; Weiß, Jürgen; Pescoller, Lukas; Weyer, Cornelia; Hahlweg, Cornelius

2015-09-01

The use of 3d printing technology seems to be a promising way for low cost prototyping, not only of mechanical, but also of optical components or systems. It is especially useful in applications where customized equipment repeatedly is subject to immediate destruction, as in experimental detonics and the like. Due to the nature of the 3D-printing process, there is a certain inner texture and therefore inhomogeneous optical behaviour to be taken into account, which also indicates mechanical anisotropy. Recent investigations are dedicated to quantification of optical properties of such printed bodies and derivation of corresponding optimization strategies for the printing process. Beside mounting, alignment and illumination means, also refractive and reflective elements are subject to investigation. The proposed measurement methods are based on an imaging nearfield scatterometer for combined volume and surface scatter measurements as proposed in previous papers. In continuation of last year's paper on the use of near field imaging, which basically is a reflective shadowgraph method, for characterization of glossy surfaces like printed matter or laminated material, further developments are discussed. The device has been extended for observation of photoelasticity effects and therefore homogeneity of polarization behaviour. A refined experimental set-up is introduced. Variation of plane of focus and incident angle are used for separation of various the images of the layers of the surface under test, cross and parallel polarization techniques are applied. Practical examples from current research studies are included.

Characterization of lipid films by an angle-interrogation surface plasmon resonance imaging device.

Science.gov (United States)

Liu, Linlin; Wang, Qiong; Yang, Zhong; Wang, Wangang; Hu, Ning; Luo, Hongyan; Liao, Yanjian; Zheng, Xiaolin; Yang, Jun

2015-04-01

Surface topographies of lipid films have an important significance in the analysis of the preparation of giant unilamellar vesicles (GUVs). In order to achieve accurately high-throughput and rapidly analysis of surface topographies of lipid films, a homemade SPR imaging device is constructed based on the classical Kretschmann configuration and an angle interrogation manner. A mathematical model is developed to accurately describe the shift including the light path in different conditions and the change of the illumination point on the CCD camera, and thus a SPR curve for each sampling point can also be achieved, based on this calculation method. The experiment results show that the topographies of lipid films formed in distinct experimental conditions can be accurately characterized, and the measuring resolution of the thickness lipid film may reach 0.05 nm. Compared with existing SPRi devices, which realize detection by monitoring the change of the reflective-light intensity, this new SPRi system can achieve the change of the resonance angle on the entire sensing surface. Thus, it has higher detection accuracy as the traditional angle-interrogation SPR sensor, with much wider detectable range of refractive index. Copyright © 2015 Elsevier B.V. All rights reserved.

Surface wave velocity tracking by bisection method

International Nuclear Information System (INIS)

Maeda, T.

2005-01-01

Calculation of surface wave velocity is a classic problem dating back to the well-known Haskell's transfer matrix method, which contributes to solutions of elastic wave propagation, global subsurface structure evaluation by simulating observed earthquake group velocities, and on-site evaluation of subsurface structure by simulating phase velocity dispersion curves and/or H/V spectra obtained by micro-tremor observation. Recently inversion analysis on micro-tremor observation requires efficient method of generating many model candidates and also stable, accurate, and fast computation of dispersion curves and Raleigh wave trajectory. The original Haskell's transfer matrix method has been improved in terms of its divergence tendency mainly by the generalized transmission and reflection matrix method with formulation available for surface wave velocity; however, root finding algorithm has not been fully discussed except for the one by setting threshold to the absolute value of complex characteristic functions. Since surface wave number (reciprocal to the surface wave velocity multiplied by frequency) is a root of complex valued characteristic function, it is intractable to use general root finding algorithm. We will examine characteristic function in phase plane to construct two dimensional bisection algorithm with consideration on a layer to be evaluated and algorithm for tracking roots down along frequency axis. (author)

Characterization of holding brake friction pad surface after pin-on-plate wear test

DEFF Research Database (Denmark)

Drago, N.; Gonzalez Madruga, D.; De Chiffre, L.

2018-01-01

This article concerns the metrological characterization of the surface on a holding brake friction material pin after a pin-on-plate (POP) wear test. The POP test induces the formation of surface plateaus that affect brake performances such as wear, friction, noise and heat. Three different...

Surface microstructures of daisy florets (Asteraceae) and characterization of their anisotropic wetting

International Nuclear Information System (INIS)

Koch, Kerstin; Bennemann, Michael; Bohn, Holger F; Barthlott, Wilhelm; Albach, Dirk C

2013-01-01

The surface microstructures on ray florets of 62 species were characterized and compared with modern phylogenetic data of species affiliation in Asteraceae to determine sculptural patterns and their occurrence in the tribes of Asteraceae. Their wettability was studied to identify structural-induced droplet adhesion, which can be used for the development of artificial surfaces for water harvesting and passive surface water transport. The wettability was characterized by contact angle (CA) and tilt angle measurements, performed on fresh ray florets and their epoxy resin replica. The CAs on ray florets varied between 104° and 156°, but water droplets did not roll off when surface was tilted at 90°. Elongated cell structures and cuticle folding orientated in the same direction as the cell elongation caused capillary forces, leading to anisotropic wetting, with extension of water droplets along the length axis of epidermis cells. The strongest elongation of the droplets was also supported by a parallel, cell-overlapping cuticle striation. In artificial surfaces made of epoxy replica of ray florets, this effect was enhanced. The distribution of the identified four structural types exhibits a strong phylogenetic signal and allows the inference of an evolutionary trend in the modification of floret epidermal cells. (paper)

Surface microstructures of daisy florets (Asteraceae) and characterization of their anisotropic wetting.

Science.gov (United States)

Koch, Kerstin; Bennemann, Michael; Bohn, Holger F; Albach, Dirk C; Barthlott, Wilhelm

2013-09-01

The surface microstructures on ray florets of 62 species were characterized and compared with modern phylogenetic data of species affiliation in Asteraceae to determine sculptural patterns and their occurrence in the tribes of Asteraceae. Their wettability was studied to identify structural-induced droplet adhesion, which can be used for the development of artificial surfaces for water harvesting and passive surface water transport. The wettability was characterized by contact angle (CA) and tilt angle measurements, performed on fresh ray florets and their epoxy resin replica. The CAs on ray florets varied between 104° and 156°, but water droplets did not roll off when surface was tilted at 90°. Elongated cell structures and cuticle folding orientated in the same direction as the cell elongation caused capillary forces, leading to anisotropic wetting, with extension of water droplets along the length axis of epidermis cells. The strongest elongation of the droplets was also supported by a parallel, cell-overlapping cuticle striation. In artificial surfaces made of epoxy replica of ray florets, this effect was enhanced. The distribution of the identified four structural types exhibits a strong phylogenetic signal and allows the inference of an evolutionary trend in the modification of floret epidermal cells.

Extraction of agar from Gelidium sesquipedale (Rhodopyta) and surface characterization of agar based films.

Science.gov (United States)

Guerrero, P; Etxabide, A; Leceta, I; Peñalba, M; de la Caba, K

2014-01-01

The chemical structure of the agar obtained from Gelidium sesquipedale (Rhodophyta) has been determined by (13)C nuclear magnetic resonance ((13)C NMR) and Fourier transform infrared spectroscopy (FTIR). Agar (AG) films with different amounts of soy protein isolate (SPI) were prepared using a thermo-moulding method, and transparent and hydrophobic films were obtained and characterized. FTIR analysis provided a detailed description of the binding groups present in the films, such as carboxylic, hydroxyl and sulfonate groups, while the surface composition was examined using X-ray photoelectron spectroscopy (XPS). The changes observed by FTIR and XPS spectra suggested interactions between functional groups of agar and SPI. This is a novel approach to the characterization of agar-based films and provides knowledge about the compatibility of agar and soy protein for further investigation of the functional properties of biodegradable films based on these biopolymers. Copyright © 2013 Elsevier Ltd. All rights reserved.

A waveless free surface flow past a submerged triangular obstacle in presence of surface tension

Directory of Open Access Journals (Sweden)

Hakima Sekhri

2016-07-01

Full Text Available We consider the Free surface flows passing a submerged triangular obstacle at the bottom of a channel. The problem is characterized by a nonlinear boundary condition on the surface of unknown configuration. The analytical exact solutions for these problems are not known. Following Dias and Vanden Broeck [6], we computed numerically the solutions via a series truncation method. These solutions depend on two parameters: the Weber number $\\alpha$ characterizing the strength of the surface tension and the angle $\\beta$ at the base characterizing the shape of the apex. Although free surface flows with surface tension admit capillary waves, it is found that solution exist only for values of the Weber number greater than $\\alpha_0$ for different configurations of the triangular obstacle.

Validation of in-line surface characterization by light scattering in Robot Assisted Polishing

DEFF Research Database (Denmark)

Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo

2014-01-01

The suitability of a commercial scattered light sensor for in-line characterization of fine surfaces in the roughness range Sa 1 – 30 nm generated by the Robot Assisted Polishing (RAP) was investigated and validated. A number of surfaces were generated and directly measured with the scattered light...

PL-PatchSurfer: A Novel Molecular Local Surface-Based Method for Exploring Protein-Ligand Interactions

Directory of Open Access Journals (Sweden)

Bingjie Hu

2014-08-01

Full Text Available Structure-based computational methods have been widely used in exploring protein-ligand interactions, including predicting the binding ligands of a given protein based on their structural complementarity. Compared to other protein and ligand representations, the advantages of a surface representation include reduced sensitivity to subtle changes in the pocket and ligand conformation and fast search speed. Here we developed a novel method named PL-PatchSurfer (Protein-Ligand PatchSurfer. PL-PatchSurfer represents the protein binding pocket and the ligand molecular surface as a combination of segmented surface patches. Each patch is characterized by its geometrical shape and the electrostatic potential, which are represented using the 3D Zernike descriptor (3DZD. We first tested PL-PatchSurfer on binding ligand prediction and found it outperformed the pocket-similarity based ligand prediction program. We then optimized the search algorithm of PL-PatchSurfer using the PDBbind dataset. Finally, we explored the utility of applying PL-PatchSurfer to a larger and more diverse dataset and showed that PL-PatchSurfer was able to provide a high early enrichment for most of the targets. To the best of our knowledge, PL-PatchSurfer is the first surface patch-based method that treats ligand complementarity at protein binding sites. We believe that using a surface patch approach to better understand protein-ligand interactions has the potential to significantly enhance the design of new ligands for a wide array of drug-targets.

PL-PatchSurfer: a novel molecular local surface-based method for exploring protein-ligand interactions.

Science.gov (United States)

Hu, Bingjie; Zhu, Xiaolei; Monroe, Lyman; Bures, Mark G; Kihara, Daisuke

2014-08-27

Structure-based computational methods have been widely used in exploring protein-ligand interactions, including predicting the binding ligands of a given protein based on their structural complementarity. Compared to other protein and ligand representations, the advantages of a surface representation include reduced sensitivity to subtle changes in the pocket and ligand conformation and fast search speed. Here we developed a novel method named PL-PatchSurfer (Protein-Ligand PatchSurfer). PL-PatchSurfer represents the protein binding pocket and the ligand molecular surface as a combination of segmented surface patches. Each patch is characterized by its geometrical shape and the electrostatic potential, which are represented using the 3D Zernike descriptor (3DZD). We first tested PL-PatchSurfer on binding ligand prediction and found it outperformed the pocket-similarity based ligand prediction program. We then optimized the search algorithm of PL-PatchSurfer using the PDBbind dataset. Finally, we explored the utility of applying PL-PatchSurfer to a larger and more diverse dataset and showed that PL-PatchSurfer was able to provide a high early enrichment for most of the targets. To the best of our knowledge, PL-PatchSurfer is the first surface patch-based method that treats ligand complementarity at protein binding sites. We believe that using a surface patch approach to better understand protein-ligand interactions has the potential to significantly enhance the design of new ligands for a wide array of drug-targets.

A non-contact 3D method to characterize the surface roughness of castings

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat; Hansen, Hans Nørgaard

2013-01-01

that the surface quality of the standard comparators was successfully evaluated and it was established that the areal parameters are the most informative for cast components. The results from the surface comparators were compared with the results from a stylus instrument. Sand cast components were also evaluated...

Surface characterization of insulin protofilaments and fibril polymorphs using tip-enhanced Raman spectroscopy (TERS).

Science.gov (United States)

Kurouski, Dmitry; Deckert-Gaudig, Tanja; Deckert, Volker; Lednev, Igor K

2014-01-07

Amyloid fibrils are β-sheet-rich protein aggregates that are strongly associated with a variety of neurodegenerative maladies, such as Alzheimer's and Parkinson's diseases. Even if the secondary structure of such fibrils is well characterized, a thorough understanding of their surface organization still remains elusive. Tip-enhanced Raman spectroscopy (TERS) is one of a few techniques that allow the direct characterization of the amino acid composition and the protein secondary structure of the amyloid fibril surface. Herein, we investigated the surfaces of two insulin fibril polymorphs with flat (flat) and left-twisted (twisted) morphology. It was found that the two differ substantially in both amino acid composition and protein secondary structure. For example, the amounts of Tyr, Pro, and His differ, as does the number of carboxyl groups on the respective surfaces, whereas the amounts of Phe and of positively charged amino and imino groups remain similar. In addition, the surface of protofilaments, the precursors of the mature flat and twisted fibrils, was investigated using TERS. The results show substantial differences with respect to the mature fibrils. A correlation of amino acid frequencies and protein secondary structures on the surface of protofilaments and on flat and twisted fibrils allowed us to propose a hypothetical mechanism for the propagation to specific fibril polymorphs. This knowledge can shed a light on the toxicity of amyloids and define the key factors responsible for fibril polymorphism. Finally, this work demonstrates the potential of TERS for the surface characterization of amyloid fibril polymorphs. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Fast and low-cost method to fabricate large-area superhydrophobic surface on steel substrate with anticorrosion and anti-icing properties

Energy Technology Data Exchange (ETDEWEB)

Yan, Wei; Liu, Hongtao, E-mail: liuht100@126.com; Sun, Qinghe; Zhu, Wei [College of Materials Science and Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China); Chen, Tianchi [College of Mechanical and Electrical Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China)

2016-07-15

A facile and quick fabrication method was proposed to prepare superhydrophobic surfaces on iron substrate by chemical immersion and subsequent stearic acid modification. The association between wettability and surface morphology was studied through altering the copper ion concentration and immersion time. Surface tension instrument, scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and electrochemical workstation were used to characterize the wettability, physical morphology, chemical composition, and corrosion resistance ability of the prepared film. Results showed that both the rough micro/nanostructures and low surface energy material play critical roles in surface wettability. The superhydrophobic film achieved a better anticorrosion property compared to barrier iron by analysis of open circuit potential, potentiodynamic polarization curves, and Nyquist plots. In addition, the superhydrophobic surface showed excellent performance of acid and alkali resistance, anti-icing, and self-cleaning through a series of environmental tests. This study provides a valid method for quick-preparation of the stable superhydrophobic surfaces, which has a promising application in steel buildings and facilities.

Microanalytical characterization of surface decoration in Majolica pottery

International Nuclear Information System (INIS)

Padilla, R.; Schalm, O.; Janssens, K.; Arrazcaeta, R.; Espen, P. van

2005-01-01

This paper presents the results of the characterization of the surface finishing works in archaeological pottery fragments belonging to several Majolica types. The homogeneity, thickness and inclusions of both ground glaze and color decorations were, among other characteristics, inspected by scanning electron microscopy X-ray analysis (SEM-EDX). The identification of the main constituents in the decoration motifs was performed by means of scanning micro X-ray fluorescence analysis. Additionally, compositional classification based on non-destructive quantitative analysis of the ground glaze was performed

Surface characterization and biodegradation behavior of magnesium implanted poly(L-lactide/caprolactone) films

Science.gov (United States)

Sokullu, Emel; Ersoy, Fulya; Yalçın, Eyyup; Öztarhan, Ahmet

2017-11-01

Biopolymers are great source for medical applications such as drug delivery, wound patch, artificial tissue studies etc., food packaging, cosmetic applications etc. due to their biocompatibility and biodegradability. Particularly, the biodegradation ability of a biomaterial makes it even advantageous for the applications. The more tunable the biodegradation rate the more desired the biopolymers. There are many ways to tune degradation rate including surface modification. In this study ion implantation method applied to biopolymer surface to determine its effect on biodegradation rate. In this study, surface modification of poly(L-lactide/caprolactone) copolymer film is practiced via Mg-ion-implantation using a MEVVA ion source. Mg ions were implanted at a fluence of 1 × 1015 ions/cm2 and ion energy of 30 keV. Surface characterization of Mg-ion-implanted samples is examined using Atomic Force Microscopy, Raman spectroscopy, contact angle measurement and FT-IR Spectroscopy. These analyses showed that the surface become more hydrophilic and rougher after the ion implantation process which is advantageous for cell attachment on medical studies. The in vitro enzymatic degradation of Mg-implanted samples was investigated in Lipase PS containing enzyme solution. Enzymatic degradation rate was examined by mass loss calculation and it is shown that Mg-implanted samples lost more than 30% of their weight while control samples lost around 20% of their weight at the end of the 16 weeks. The evaluation of the results confirmed that Mg-ion-implantation on poly(L-lactide/caprolactone) films make the surface rougher and more hydrophilic and changes the organic structure on the surface. On the other hand, ion implantation has increased the biodegradation rate.

Facile Fabrication and Characterization of a PDMS-Derived Candle Soot Coated Stable Biocompatible Superhydrophobic and Superhemophobic Surface.

Science.gov (United States)

Iqbal, R; Majhy, B; Sen, A K

2017-09-13

We report a simple, inexpensive, rapid, and one-step method for the fabrication of a stable and biocompatible superhydrophobic and superhemophobic surface. The proposed surface comprises candle soot particles embedded in a mixture of PDMS+n-hexane serving as the base material. The mechanism responsible for the superhydrophobic behavior of the surface is explained, and the surface is characterized based on its morphology and elemental composition, wetting properties, mechanical and chemical stability, and biocompatibility. The effect of %n-hexane in PDMS, the thickness of the PDMS+n-hexane layer (in terms of spin coating speed) and sooting time on the wetting property of the surface is studied. The proposed surface exhibits nanoscale surface asperities (average roughness of 187 nm), chemical compositions of soot particles, very high water and blood repellency along with excellent mechanical and chemical stability and excellent biocompatibility against blood sample and biological cells. The water contact angle and roll-off angle is measured as 160° ± 1° and 2°, respectively, and the blood contact angle is found to be 154° ± 1°, which indicates that the surface is superhydrophobic and superhemophobic. The proposed superhydrophobic and superhemophobic surface offers significantly improved (>40%) cell viability as compared to glass and PDMS surfaces.

Semi-automated potentiometric titration method for uranium characterization.

Science.gov (United States)

Cristiano, B F G; Delgado, J U; da Silva, J W S; de Barros, P D; de Araújo, R M S; Lopes, R T

2012-07-01

The manual version of the potentiometric titration method has been used for certification and characterization of uranium compounds. In order to reduce the analysis time and the influence of the analyst, a semi-automatic version of the method was developed in the Brazilian Nuclear Energy Commission. The method was applied with traceability assured by using a potassium dichromate primary standard. The combined standard uncertainty in determining the total concentration of uranium was around 0.01%, which is suitable for uranium characterization. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characterization of D2 tool steel friction surfaced coatings over low carbon steel

International Nuclear Information System (INIS)

Sekharbabu, R.; Rafi, H. Khalid; Rao, K. Prasad

2013-01-01

Highlights: • Solid state coating by friction surfacing method. • D2 tool steel is coated over relatively softer low carbon steel. • Defect free interface between tool steel coating and low carbon steel substrate. • D2 coatings exhibited higher hardness and good wear resistance. • Highly refined martensitic microstructure in the coating. - Abstract: In this work D2 tool steel coating is produced over a low carbon steel substrate using friction surfacing process. The process parameters are optimized to get a defect free coating. Microstructural characterization is carried out using optical microscopy, scanning electron microscopy and X-ray diffraction. Infrared thermography is used to measure the thermal profile during friction surfacing of D2 steel. Wear performance of the coating is studied using Pin-on-Disk wear tests. A lower rotational speed of the consumable rod and higher translational speed of the substrate is found to result in thinner coatings. Friction surfaced D2 steel coating showed fine-grained martensitic microstructure compared to the as-received consumable rod which showed predominantly ferrite microstructure. Refinement of carbides in the coating is observed due to the stirring action of the process. The infrared thermography studies showed the peak temperature attained by the D2 coating to be about 1200 °C. The combined effect of martensitic microstructure and refined carbides resulted in higher hardness and wear resistance of the coating

Surface characterization of alloy Ti-6Al-7Nb treated plasma

International Nuclear Information System (INIS)

Moura, J.K.L.; Macedo, H.R.A.; Brito, E.M.; Brandim, A.S.

2014-01-01

Plasma surface modifications are subject of numerous studies to improve the quality of a given material. Titanium and its alloys are widely used in biomedical applications and plasma treatment technique is increasingly used to improve the surface properties thereof. The research have a objective in the comparative analysis of the change in microstructure of Ti-6Al-7Nb alloys after treatment of plasma nitriding. The technical are: nitriding with cathode cage (NGC) and planar discharge. The characterization was obtained by MEV (Scanning Electronic Microscope) and hardness. The results was compared about the better surface modification that meets future prospects of the biocompatibility of the alloy.(author)

Characterization of a Laser Surface-Treated Martensitic Stainless Steel.

Science.gov (United States)

Al-Sayed, S R; Hussein, A A; Nofal, A A; Hassab Elnaby, S I; Elgazzar, H

2017-05-29

Laser surface treatment was carried out on AISI 416 machinable martensitic stainless steel containing 0.225 wt.% sulfur. Nd:YAG laser with a 2.2-KW continuous wave was used. The aim was to compare the physical and chemical properties achieved by this type of selective surface treatment with those achieved by the conventional treatment. Laser power of different values (700 and 1000 W) with four corresponding different laser scanning speeds (0.5, 1, 2, and 3 m•min-1) was adopted to reach the optimum conditions for impact toughness, wear, and corrosion resistance for laser heat treated (LHT) samples. The 0 °C impact energy of LHT samples indicated higher values compared to the conventionally heat treated (CHT) samples. This was accompanied by the formation of a hard surface layer and a soft interior base metal. Microhardness was studied to determine the variation of hardness values with respect to the depth under the treated surface. The wear resistance at the surface was enhanced considerably. Microstructure examination was characterized using optical and scanning electron microscopes. The corrosion behavior of the LHT samples was also studied and its correlation with the microstructures was determined. The corrosion data was obtained in 3.5% NaCl solution at room temperature by means of a potentiodynamic polarization technique.

Spectroscopic characterization of the on-surface induced (cyclo) dehydrogenation of a N-heteroaromatic compound on noble metal surfaces

Czech Academy of Sciences Publication Activity Database

Palacio, I.; Pinardi, A. L.; Martínez, J. I.; Preobrajenski, A.; Cossaro, A.; Jančařík, Andrej; Stará, Irena G.; Starý, Ivo; Méndez, J.; Martín-Gago, J.A.; López, M.F.

2017-01-01

Roč. 19, č. 33 (2017), s. 22454-22461 ISSN 1463-9076 Institutional support: RVO:61388963 Keywords : dibenzohelicene * on-surface (cyclo)dehydrogenation * spectroscopic characterization Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 4.123, year: 2016

Characterization and flip angle calibration of 13C surface coils for hyperpolarization studies

DEFF Research Database (Denmark)

Hansen, Rie Beck; Gutte, Henrik; Larsen, Majbrit M E

The aim of the present work is to address the challenge of optimal The aim of the present work is to address the challenge of optimal flflip angle calibration of ip angle calibration of C surface coils in C surface coils in hyperpolarization studies. To this end, we characterize the spatial pro h...

Analytical methods of radwaste characterization

International Nuclear Information System (INIS)

Garcia, C.M.

1994-10-01

In view of the need to carry out more extensive studies on the design of newly proposed methods for the treatment of radioactive wastes collected at PNRI, this study is aimed to provide a guide in the characterization of wastes which is a preparatory step for a well-planned waste processing. (auth.). 8 refs

Electronic and structural characterizations of unreconstructed {0001} surfaces and the growth of graphene overlayers

International Nuclear Information System (INIS)

Emtsev, Konstantin

2009-01-01

The present work is focused on the characterization of the clean unreconstructed SiC{0001} surfaces and the growth of graphene overlayers thereon. Electronic properties of SiC surfaces and their interfaces with graphene and few layer graphene films were investigated by means of angle resolved photoelectron spectroscopy, X-ray photoelectron spectroscopy and low energy electron diffraction. Structural characterizations of the epitaxial graphene films grown on SiC were carried out by atomic force microscopy and low energy electron microscopy. Supplementary data was obtained by scanning tunneling microscopy. (orig.)

Characterization of metallic surfaces in phosphorous-bronze ordered packings

International Nuclear Information System (INIS)

Sandru, Claudia; Titescu, Gh.

1997-01-01

Copper and its alloys, particularly the phosphorous bronze, are characterized by a high water wettability as compared with other materials. This feature led to utilization of phosphorous bronze in fabrication of contact elements, a packing type equipping the distillation columns. For heavy water separation by isotopic distillation under vacuum, ordered packings of phosphorous bronze networks were fabricated. The superior performances of these packings are determined by the material and also by the geometrical form and the state of the metallic surface. Thus, a procedure of evaluating the wettability has been developed, based on tests of the network material. The results of the tests constitute a criterion of rating the functional performances of packings, particularly of their efficiencies. Also, investigation techniques of the chemical composition and of the thickness of superficial layer on the packing were developed. It was found that the packing surface presents a layer of about 5-20 μm formed mainly by oxides of copper, tin, and, depending on the packing treatment, of oxides of other elements coming from the treatment agent. The paper presents characterization of phosphorous bronze treated with potassium permanganate, a specific treatment for improving the functional performances of the packings used in the heavy water concentration and re-concentration installations

Method of measuring surface density

International Nuclear Information System (INIS)

Gregor, J.

1982-01-01

A method is described of measuring surface density or thickness, preferably of coating layers, using radiation emitted by a suitable radionuclide, e.g., 241 Am. The radiation impinges on the measured material, e.g., a copper foil and in dependence on its surface density or thickness part of the flux of impinging radiation is reflected and part penetrates through the material. The radiation which has penetrated through the material excites in a replaceable adjustable backing characteristic radiation of an energy close to that of the impinging radiation (within +-30 keV). Part of the flux of the characteristic radiation spreads back to the detector, penetrates through the material in which in dependence on surface density or thickness of the coating layer it is partly absorbed. The flux of the penetrated characteristic radiation impinging on the face of the detector is a function of surface density or thickness. Only that part of the energy is evaluated of the energy spectrum which corresponds to the energy of characteristic radiation. (B.S.)

Characterisation of multifunctional surfaces with robust filters

DEFF Research Database (Denmark)

Friis, Kasper Storgaard; Godi, Alessandro; De Chiffre, Leonardo

2011-01-01

Research has shown that engineered surfaces containing lubrication pockets and directional surface texture can decrease wear and friction in sliding or rolling contacts. A new generation of multifunctional (MUFU) surfaces is achieved by hard machining followed by robot assisted polishing (RAP......). The novel production method allows for a large degree of freedom in specifying surface characteristics such as frequency, depth and volume of the lubricant retention valleys, as well as the amount of load bearing area and the surface roughness. The surfaces cannot readily be characterized by means...... of conventional roughness parameters due to the multi-process production method involved. A series of MUFU surfaces were characterized by using the ISO 13565 standard for stratified surfaces and it is shown that the standard in some cases is inadequate for characterisation of a MUFU surface. To improve...

Surface modifying method for metal member

International Nuclear Information System (INIS)

Amano, Kazuo; Enomoto, Kunio; Hirano, Akihiko; Hirano, Atsuya; Hattori, Shigeo; Hayashi, Eisaku; Ueyama, Toshiharu; Hayashi, Makoto

1998-01-01

A surface of a metal member such as carbon steel to be used in a corrosion circumstance such as in a nuclear power plant and a thermoelectric plant are polished. A printing method is conducted for removing obstacles on the surface of the member. Namely, a photographing printing paper immersed in a diluted sulfuric acid solution is appended tightly to the portion with its surface polished smoothly. Sulfur present in the form of an obstacle of MnS or present alone in the material reacts with the sulfuric acid to form a sulfuric acid gas, and reacts with Ag of the printing paper to discolor the printing paper to brown. When a peeled printing paper is discolored to brown, sulfur printing is repeated. After conforming that the peeled printing paper is white, the surface is washed. Subsequently, surface plasticization is conducted by water jet peening or shot peening. (I.N.)

Spatial characterization of nanotextured surfaces by visual color imaging

DEFF Research Database (Denmark)

Feidenhans'l, Nikolaj Agentoft; Murthy, Swathi; Madsen, Morten H.

2016-01-01

We present a method using an ordinary color camera to characterize nanostructures from the visual color of the structures. The method provides a macroscale overview image from which micrometer-sized regions can be analyzed independently, hereby revealing long-range spatial variations...

Spatially telescoping measurements for improved characterization of groundwater-surface water interactions

Science.gov (United States)

Kikuchi, Colin; Ferre, Ty P.A.; Welker, Jeffery M.

2012-01-01

The suite of measurement methods available to characterize fluxes between groundwater and surface water is rapidly growing. However, there are few studies that examine approaches to design of field investigations that include multiple methods. We propose that performing field measurements in a spatially telescoping sequence improves measurement flexibility and accounts for nested heterogeneities while still allowing for parsimonious experimental design. We applied this spatially telescoping approach in a study of ground water-surface water (GW-SW) interaction during baseflow conditions along Lucile Creek, located near Wasilla, Alaska. Catchment-scale data, including channel geomorphic indices and hydrogeologic transects, were used to screen areas of potentially significant GW-SW exchange. Specifically, these data indicated increasing groundwater contribution from a deeper regional aquifer along the middle to lower reaches of the stream. This initial assessment was tested using reach-scale estimates of groundwater contribution during baseflow conditions, including differential discharge measurements and the use of chemical tracers analyzed in a three-component mixing model. The reach-scale measurements indicated a large increase in discharge along the middle reaches of the stream accompanied by a shift in chemical composition towards a regional groundwater end member. Finally, point measurements of vertical water fluxes -- obtained using seepage meters as well as temperature-based methods -- were used to evaluate spatial and temporal variability of GW-SW exchange within representative reaches. The spatial variability of upward fluxes, estimated using streambed temperature mapping at the sub-reach scale, was observed to vary in relation to both streambed composition and the magnitude of groundwater contribution from differential discharge measurements. The spatially telescoping approach improved the efficiency of this field investigation. Beginning our assessment

Characterization of Boroaluminosilicate Glass Surface Structures by B k-edge NEXAFS

Energy Technology Data Exchange (ETDEWEB)

R Schaut; R Lobello; K Mueller; C Pantano

2011-12-31

Techniques traditionally used to characterize bulk glass structure (NMR, IR, etc.) have improved significantly, but none provide direct measurement of local atomic coordination of glass surface species. Here, we used Near-Edge X-ray Absorption Fine Structure (NEXAFS) as a direct measure of atomic structure at multicomponent glass surfaces. Focusing on the local chemical structure of boron, we address technique-related issues of calibration, quantification, and interactions of the beam with the material. We demonstrate that beam-induced adsorption and structural damage can occur within the timeframe of typical measurements. The technique is then applied to the study of various fracture surfaces where it is shown that adsorption and reaction of water with boroaluminosilicate glass surfaces induces structural changes in the local coordination of boron, favoring B{sup IV} species after reaction.

Short communication: Unexpected findings on the physicochemical characterization of the silver nanoparticle surface

Science.gov (United States)

Loran, S.; Yelon, A.; Sacher, E.

2018-01-01

The bactericidal properties of silver nanoparticles (Ag NPs) have been variously attributed to the action of the NP surface and/or the Ag ions released therefrom. However, the published literature does not appear to contain any information on the physicochemical characterization of the NP surface. Herein, we report on the surprisingly reactive surface of the Ag NP, which has an almost total lack of free Ag on atmospheric exposure. Rather, an abundance of surface hydrocarbons, hydrides and oxides, as well as amines and oxidized N, argues for a reinterpretation of their bactericidal action.

Optical microtopographic inspection of asphalt pavement surfaces

Science.gov (United States)

Costa, Manuel F. M.; Freitas, E. F.; Torres, H.; Cerezo, V.

2017-08-01

Microtopographic and rugometric characterization of surfaces is routinely and effectively performed non-invasively by a number of different optical methods. Rough surfaces are also inspected using optical profilometers and microtopographer. The characterization of road asphalt pavement surfaces produced in different ways and compositions is fundamental for economical and safety reasons. Having complex structures, including topographically with different ranges of form error and roughness, the inspection of asphalt pavement surfaces is difficult to perform non-invasively. In this communication we will report on the optical non-contact rugometric characterization of the surface of different types of road pavements performed at the Microtopography Laboratory of the Physics Department of the University of Minho.

Current practices in corrosion, surface characterization, and nickel leach testing of cardiovascular metallic implants.

Science.gov (United States)

Nagaraja, Srinidhi; Di Prima, Matthew; Saylor, David; Takai, Erica

2017-08-01

In an effort to better understand current test practices and improve nonclinical testing of cardiovascular metallic implants, the Food and Drug Administration (FDA) held a public workshop on Cardiovascular Metallic Implants: corrosion, surface characterization, and nickel leaching. The following topics were discussed: (1) methods used for corrosion assessments, surface characterization techniques, and nickel leach testing of metallic cardiovascular implant devices, (2) the limitations of each of these in vitro tests in predicting in vivo performance, (3) the need, utility, and circumstances when each test should be considered, and (4) the potential testing paradigms, including acceptance criteria for each test. In addition to the above topics, best practices for these various tests were discussed, and knowledge gaps were identified. Prior to the workshop, discussants had the option to provide feedback and information on issues relating to each of the topics via a voluntary preworkshop assignment. During the workshop, the pooled responses were presented and a panel of experts discussed the results. This article summarizes the proceedings of this workshop and background information provided by workshop participants. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. J Biomed Mater Res Part B: Appl Biomater, 105B: 1330-1341, 2017. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Transuranic waste characterization sampling and analysis methods manual. Revision 1

International Nuclear Information System (INIS)

Suermann, J.F.

1996-04-01

This Methods Manual provides a unified source of information on the sampling and analytical techniques that enable Department of Energy (DOE) facilities to comply with the requirements established in the current revision of the Transuranic Waste Characterization Quality Assurance Program Plan (QAPP) for the Waste Isolation Pilot Plant (WIPP) Transuranic (TRU) Waste Characterization Program (the Program) and the WIPP Waste Analysis Plan. This Methods Manual includes all of the testing, sampling, and analytical methodologies accepted by DOE for use in implementing the Program requirements specified in the QAPP and the WIPP Waste Analysis Plan. The procedures in this Methods Manual are comprehensive and detailed and are designed to provide the necessary guidance for the preparation of site-specific procedures. With some analytical methods, such as Gas Chromatography/Mass Spectrometry, the Methods Manual procedures may be used directly. With other methods, such as nondestructive characterization, the Methods Manual provides guidance rather than a step-by-step procedure. Sites must meet all of the specified quality control requirements of the applicable procedure. Each DOE site must document the details of the procedures it will use and demonstrate the efficacy of such procedures to the Manager, National TRU Program Waste Characterization, during Waste Characterization and Certification audits

Optimized method for manufacturing large aspheric surfaces

Science.gov (United States)

Zhou, Xusheng; Li, Shengyi; Dai, Yifan; Xie, Xuhui

2007-12-01

Aspheric optics are being used more and more widely in modern optical systems, due to their ability of correcting aberrations, enhancing image quality, enlarging the field of view and extending the range of effect, while reducing the weight and volume of the system. With optical technology development, we have more pressing requirement to large-aperture and high-precision aspheric surfaces. The original computer controlled optical surfacing (CCOS) technique cannot meet the challenge of precision and machining efficiency. This problem has been thought highly of by researchers. Aiming at the problem of original polishing process, an optimized method for manufacturing large aspheric surfaces is put forward. Subsurface damage (SSD), full aperture errors and full band of frequency errors are all in control of this method. Lesser SSD depth can be gained by using little hardness tool and small abrasive grains in grinding process. For full aperture errors control, edge effects can be controlled by using smaller tools and amendment model with material removal function. For full band of frequency errors control, low frequency errors can be corrected with the optimized material removal function, while medium-high frequency errors by using uniform removing principle. With this optimized method, the accuracy of a K9 glass paraboloid mirror can reach rms 0.055 waves (where a wave is 0.6328μm) in a short time. The results show that the optimized method can guide large aspheric surface manufacturing effectively.

Potentialities of some surface characterization techniques for the development of titanium biomedical alloys

Directory of Open Access Journals (Sweden)

P.S. Vanzillotta

2004-09-01

Full Text Available Bone formation around a metallic implant is a complex process that involves micro- and nanometric interactions. Several surface treatments, including coatings were developed in order to obtain faster osseointegration. To understand the role of these surface treatments on bone formation it is necessary to choose adequate characterization techniques. Among them, we have selected electron microscopy, profilometry, atomic force microscopy (AFM and X-ray photoelectron spectroscopy (XPS to describe them briefly. Examples of the potentialities of these techniques on the characterization of titanium for biomedical applications were also presented and discussed. Unfortunately more than one technique is usually necessary to describe conveniently the topography (scanning electron microsocopy, profilometry and/or AFM and the chemical state (XPS of the external layer of the material surface. The employment of the techniques above described can be useful especially for the development of new materials or products.

Physicochemical characterization of engineered nanoparticles under physiological conditions: effect of culture media components and particle surface coating.

Science.gov (United States)

Fatisson, Julien; Quevedo, Ivan R; Wilkinson, Kevin J; Tufenkji, Nathalie

2012-03-01

The use of engineered nanoparticles (ENPs) in commercial products has increased substantially over the last few years. Some research has been conducted in order to determine whether or not such materials are cytotoxic, but questions remain regarding the role that physiological media and sera constituents play in ENP aggregation or stabilization. In this study, several characterization methods were used to evaluate the particle size and surface potential of 6 ENPs suspended in a number of culture media and in the presence of different culture media constituents. Dynamic light scattering (DLS) and fluorescence correlation spectroscopy (FCS) were employed for size determinations. Results were interpreted on the basis of ENP surface potentials evaluated from particle electrophoretic mobilities (EPM). Measurements made after 24h of incubation at 37°C showed that the cell culture medium constituents had only moderate impact on the physicochemical properties of the ENP, although incubation in bovine serum albumin destabilized the colloidal system. In contrast, most of the serum proteins increased colloidal stabilization. Moreover, the type of ENP surface modification played a significant role in ENP behavior whereby the complexity of interactions between the ENPs and the medium components generally decreased with increasing complexity of the particle surface. This investigation emphasizes the importance of ENP characterization under conditions that are representative of cell culture media or physiological conditions for improved assessments of nanoparticle cytotoxicity. Copyright © 2011 Elsevier B.V. All rights reserved.

Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

International Nuclear Information System (INIS)

Mayr, Lukas; Klötzer, Bernhard; Penner, Simon; Rameshan, Raffael; Rameshan, Christoph

2014-01-01

An ultra-high vacuum (UHV) setup for “real” and “inverse” model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, “magic angle”) and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown

Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

Science.gov (United States)

Mayr, Lukas; Rameshan, Raffael; Klötzer, Bernhard; Penner, Simon; Rameshan, Christoph

2014-05-01

An ultra-high vacuum (UHV) setup for "real" and "inverse" model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, "magic angle") and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown.

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...... a grating period Λ2 in the longitudinal direction, where the longitudinal direction is orthogonal to the transverse direction. A grating period spacing ΔΛ = Λ1 - Λ2 is finite. Further, the first and second grating periods are chosen to provide optical resonances for light respectively in a first...... wavelength band and a second wavelength band, light is being emitted, transmitted, or reflected in an out-of-plane direction, wherein the first wavelength band and the second wavelength band are at least partially non-overlapping in wavelength. The system further comprises a light source for illuminating...

Molecular layer deposition of APTES on silicon nanowire biosensors: Surface characterization, stability and pH response

International Nuclear Information System (INIS)

Liang, Yuchen; Huang, Jie; Zang, Pengyuan; Kim, Jiyoung; Hu, Walter

2014-01-01

Graphical abstract: - Abstract: We report the use of molecular layer deposition (MLD) for depositing 3-aminopropyltriethoxysilane (APTES) on a silicon dioxide surface. The APTES monolayer was characterized using spectroscopic ellipsometry, contact angle goniometry, and atomic force microscopy. Effects of reaction time of repeating pulses and simultaneous feeding of water vapor with APTES were tested. The results indicate that the synergistic effects of water vapor and reaction time are significant for the formation of a stable monolayer. Additionally, increasing the number of repeating pulses improved the APTES surface coverage but led to saturation after 10 pulses. In comparing MLD with solution-phase deposition, the APTES surface coverage and the surface quality were nearly equivalent. The hydrolytic stability of the resulting films was also studied. The results confirmed that the hydrolysis process was necessary for MLD to obtain stable surface chemistry. Furthermore, we compared the pH sensing results of Si nanowire field effect transistors (Si NWFETs) modified by both the MLD and solution methods. The highly repeatable pH sensing results reflected the stability of APTES monolayers. The results also showed an improved pH response of the sensor prepared by MLD compared to the one prepared by the solution treatment, which indicated higher surface coverage of APTES

Molecular layer deposition of APTES on silicon nanowire biosensors: Surface characterization, stability and pH response

Science.gov (United States)

Liang, Yuchen; Huang, Jie; Zang, Pengyuan; Kim, Jiyoung; Hu, Walter

2014-12-01

We report the use of molecular layer deposition (MLD) for depositing 3-aminopropyltriethoxysilane (APTES) on a silicon dioxide surface. The APTES monolayer was characterized using spectroscopic ellipsometry, contact angle goniometry, and atomic force microscopy. Effects of reaction time of repeating pulses and simultaneous feeding of water vapor with APTES were tested. The results indicate that the synergistic effects of water vapor and reaction time are significant for the formation of a stable monolayer. Additionally, increasing the number of repeating pulses improved the APTES surface coverage but led to saturation after 10 pulses. In comparing MLD with solution-phase deposition, the APTES surface coverage and the surface quality were nearly equivalent. The hydrolytic stability of the resulting films was also studied. The results confirmed that the hydrolysis process was necessary for MLD to obtain stable surface chemistry. Furthermore, we compared the pH sensing results of Si nanowire field effect transistors (Si NWFETs) modified by both the MLD and solution methods. The highly repeatable pH sensing results reflected the stability of APTES monolayers. The results also showed an improved pH response of the sensor prepared by MLD compared to the one prepared by the solution treatment, which indicated higher surface coverage of APTES.

Characterization of deep nanoscale surface trenches with AFM using thin carbon nanotube probes in amplitude-modulation and frequency-force-modulation modes

International Nuclear Information System (INIS)

Solares, Santiago D

2008-01-01

The characterization of deep surface trenches with atomic force microscopy (AFM) presents significant challenges due to the sharp step edges that disturb the instrument and prevent it from faithfully reproducing the sample topography. Previous authors have developed AFM methodologies to successfully characterize semiconductor surface trenches with dimensions on the order of tens of nanometers. However, the study of imaging fidelity for features with dimensions smaller than 10 nm has not yet received sufficient attention. Such a study is necessary because small features in some cases lead to apparently high-quality images that are distorted due to tip and sample mechanical deformation. This paper presents multi-scale simulations, illustrating common artifacts affecting images of nanoscale trenches taken with fine carbon nanotube probes within amplitude-modulation and frequency-force-modulation AFM (AM-AFM and FFM-AFM, respectively). It also describes a methodology combining FFM-AFM with a step-in/step-out algorithm analogous to that developed by other groups for larger trenches, which can eliminate the observed artifacts. Finally, an overview of the AFM simulation methods is provided. These methods, based on atomistic and continuum simulation, have been previously used to study a variety of samples including silicon surfaces, carbon nanotubes and biomolecules

Quantitative characterization of the atomic-scale structure of oxyhydroxides in rusts formed on steel surfaces

International Nuclear Information System (INIS)

Saito, M.; Suzuki, S.; Kimura, M.; Suzuki, T.; Kihira, H.; Waseda, Y.

2005-01-01

Quantitative X-ray structural analysis coupled with anomalous X-ray scattering has been used for characterizing the atomic-scale structure of rust formed on steel surfaces. Samples were prepared from rust layers formed on the surfaces of two commercial steels. X-ray scattered intensity profiles of the two samples showed that the rusts consisted mainly of two types of ferric oxyhydroxide, α-FeOOH and γ-FeOOH. The amounts of these rust components and the realistic atomic arrangements in the components were estimated by fitting both the ordinary and the environmental interference functions with a model structure calculated using the reverse Monte Carlo simulation technique. The two rust components were found to be the network structure formed by FeO 6 octahedral units, the network structure itself deviating from the ideal case. The present results also suggest that the structural analysis method using anomalous X-ray scattering and the reverse Monte Carlo technique is very successful in determining the atomic-scale structure of rusts formed on the steel surfaces

An expert system to characterize the surface morphological properties according to their functionalities

International Nuclear Information System (INIS)

Bigerelle, M; Mathia, T; Iost, A; Correvits, T; Anselme, K

2011-01-01

In this paper we propose a new methodology to characterize the morphological properties of a surface in relation with its functionality (tribological properties, surface coating adhesion, brightness, wettability...). We create a software based on experimental design and surface profile recording. Using an appropriate database structure, the roughness parameters are automatically computed at different scales. The surface files are saved in a hard disk directory and roughness parameters are computed at different scales. Finally, a statistical analysis system proposes the roughness parameter (or the pair of roughness parameters) that better describe(s) the functionality of the surface and the spatial scales at which the parameter(s) is (are) the more relevant.

An expert system to characterize the surface morphological properties according to their functionalities

Energy Technology Data Exchange (ETDEWEB)

Bigerelle, M [Laboratoire Roberval, UMR 6253, UTC/CNRS, UTC Centre de Recherches de Royallieu BP 20529, 60205 Compiegne France stol BS1 6BE (United Kingdom); Mathia, T [Laboratoire de Tribologie et Dynamique des Systemes, UMR 5513, Ecole Centrale de Lyon, 36 Av Guy de Collongue, 69134 Ecully Cedex (France); Iost, A [Laboratoire de Mecanique de Lille, UMR CNRS 8107, Arts et Metiers ParisTech - Lille, 8, boulevard Louis XIV 59046 Lille (France); Correvits, T [Laboratoire de Metrologie. Arts et Metiers ParisTech, ENSAM, 8 boulevard Louis XIV, 59046 LILLE Cedex (France); Anselme, K, E-mail: maxence.bigerelle@utc.fr [Institut De Sciences Des Materiaux De Mulhouse, CNRS LRC 7228, 15, rue Jean Starcky, Universite De Haute-Alsace, BP 2488, 68057 Mulhouse (France)

2011-08-19

In this paper we propose a new methodology to characterize the morphological properties of a surface in relation with its functionality (tribological properties, surface coating adhesion, brightness, wettability...). We create a software based on experimental design and surface profile recording. Using an appropriate database structure, the roughness parameters are automatically computed at different scales. The surface files are saved in a hard disk directory and roughness parameters are computed at different scales. Finally, a statistical analysis system proposes the roughness parameter (or the pair of roughness parameters) that better describe(s) the functionality of the surface and the spatial scales at which the parameter(s) is (are) the more relevant.

3D modeling to characterize lamina cribrosa surface and pore geometries using in vivo images from normal and glaucomatous eyes

Science.gov (United States)

Sredar, Nripun; Ivers, Kevin M.; Queener, Hope M.; Zouridakis, George; Porter, Jason

2013-01-01

En face adaptive optics scanning laser ophthalmoscope (AOSLO) images of the anterior lamina cribrosa surface (ALCS) represent a 2D projected view of a 3D laminar surface. Using spectral domain optical coherence tomography images acquired in living monkey eyes, a thin plate spline was used to model the ALCS in 3D. The 2D AOSLO images were registered and projected onto the 3D surface that was then tessellated into a triangular mesh to characterize differences in pore geometry between 2D and 3D images. Following 3D transformation of the anterior laminar surface in 11 normal eyes, mean pore area increased by 5.1 ± 2.0% with a minimal change in pore elongation (mean change = 0.0 ± 0.2%). These small changes were due to the relatively flat laminar surfaces inherent in normal eyes (mean radius of curvature = 3.0 ± 0.5 mm). The mean increase in pore area was larger following 3D transformation in 4 glaucomatous eyes (16.2 ± 6.0%) due to their more steeply curved laminar surfaces (mean radius of curvature = 1.3 ± 0.1 mm), while the change in pore elongation was comparable to that in normal eyes (−0.2 ± 2.0%). This 3D transformation and tessellation method can be used to better characterize and track 3D changes in laminar pore and surface geometries in glaucoma. PMID:23847739

Characterization of a Laser Surface-Treated Martensitic Stainless Steel

Directory of Open Access Journals (Sweden)

S.R. Al-Sayed

2017-05-01

Full Text Available Laser surface treatment was carried out on AISI 416 machinable martensitic stainless steel containing 0.225 wt.% sulfur. Nd:YAG laser with a 2.2-KW continuous wave was used. The aim was to compare the physical and chemical properties achieved by this type of selective surface treatment with those achieved by the conventional treatment. Laser power of different values (700 and 1000 W with four corresponding different laser scanning speeds (0.5, 1, 2, and 3 m•min−1 was adopted to reach the optimum conditions for impact toughness, wear, and corrosion resistance for laser heat treated (LHT samples. The 0 °C impact energy of LHT samples indicated higher values compared to the conventionally heat treated (CHT samples. This was accompanied by the formation of a hard surface layer and a soft interior base metal. Microhardness was studied to determine the variation of hardness values with respect to the depth under the treated surface. The wear resistance at the surface was enhanced considerably. Microstructure examination was characterized using optical and scanning electron microscopes. The corrosion behavior of the LHT samples was also studied and its correlation with the microstructures was determined. The corrosion data was obtained in 3.5% NaCl solution at room temperature by means of a potentiodynamic polarization technique.

Optical methods for characterization of surface structures on a nanometer scale

DEFF Research Database (Denmark)

Gregersen, Niels

2007-01-01

When studying a sample with subwavelength features using conventional microscopy, the diffraction limit sets a lower bound to the resolution achievable. In this work the possiblity of circumventing the diffraction limit by employing a scanning near-field optical microscope (SNOM) to perform...... the characterization is investigated. Experimental SNOM images of the optical field distribution above a deep grating are analyzed with the purpose of identifying the grating topography, and transfer functions describing the coupling of the free-space field to the guided mode of the SNOM fiber are determined...

Spinorial characterizations of surfaces into three-dimensional homogeneous manifolds

Science.gov (United States)

Roth, Julien

2010-06-01

We give spinorial characterizations of isometrically immersed surfaces into three-dimensional homogeneous manifolds with four-dimensional isometry group in terms of the existence of a particular spinor field. This generalizes works by Friedrich for R3 and Morel for S3 and H3. The main argument is the interpretation of the energy-momentum tensor of such a spinor field as the second fundamental form up to a tensor depending on the structure of the ambient space.

The estimation of dynamic contact angle of ultra-hydrophobic surfaces using inclined surface and impinging droplet methods

Science.gov (United States)

Jasikova, Darina; Kotek, Michal

2014-03-01

The development of industrial technology also brings with optimized surface quality, particularly where there is contact with food. Application ultra-hydrophobic surface significantly reduces the growth of bacteria and facilitates cleaning processes. Testing and evaluation of surface quality are used two methods: impinging droplet and inclined surface method optimized with high speed shadowgraphy, which give information about dynamic contact angle. This article presents the results of research into new methods of measuring ultra-hydrophobic patented technology.

Characterization and reactivity of sodium aluminoborosilicate glass fiber surfaces

Energy Technology Data Exchange (ETDEWEB)

Ortiz Rivera, Lymaris, E-mail: luo105@psu.edu [Materials Research Institute, Pennsylvania State University, University Park, PA 16802 (United States); Bakaev, Victor A.; Banerjee, Joy [Materials Research Institute, Pennsylvania State University, University Park, PA 16802 (United States); Mueller, Karl T. [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States); Pantano, Carlo G. [Materials Research Institute, Pennsylvania State University, University Park, PA 16802 (United States); Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)

2016-05-01

Highlights: • XPS revealed that these fiber surfaces contain sodium carbonate weathering products. • IGC–MS data confirms the products of acetic acid reaction with sodium carbonate. • NMR data shows two closely spaced, but distinct sodium carboxylate peaks. • Acetic acid reacts with both sodium in the glass and sodium in the sodium carbonate. - Abstract: Multicomponent complex oxides, such as sodium aluminoborosilicate glass fibers, are important materials used for thermal insulation in buildings and homes. Although the surface properties of single oxides, such as silica, have been extensively studied, less is known about the distribution of reactive sites at the surface of multicomponent oxides. Here, we investigated the reactivity of sodium aluminoborosilicate glass fiber surfaces for better understanding of their interface chemistry and bonding with acrylic polymers. Acetic acid (with and without a {sup 13}C enrichment) was used as a probe representative of the carboxylic functional groups in many acrylic polymers and adhesives. Inverse gas chromatography coupled to a mass spectrometer (IGC–MS), and solid state nuclear magnetic resonance (NMR), were used to characterize the fiber surface reactions and surface chemical structure. In this way, we discovered that both sodium ions in the glass surface, as well as sodium carbonate salts that formed on the surface due to the intrinsic reactivity of this glass in humid air, are primary sites of interaction with the carboxylic acid. Surface analysis by X-ray photoelectron spectroscopy (XPS) confirmed the presence of sodium carbonates on these surfaces. Computer simulations of the interactions between the reactive sites on the glass fiber surface with acetic acid were performed to evaluate energetically favorable reactions. The adsorption reactions with sodium in the glass structure provide adhesive bonding sites, whereas the reaction with the sodium carbonate consumes the acid to form sodium-carboxylate, H

Application of Surface Geophysical Methods, With Emphasis on Magnetic Resonance Soundings, to Characterize the Hydrostratigraphy of the Brazos River Alluvium Aquifer, College Station, Texas, July 2006 - A Pilot Study

Science.gov (United States)

Shah, Sachin D.; Kress, Wade H.; Legchenko, Anatoly

2007-01-01

The U.S. Geological Survey, in cooperation with the Texas Water Development Board, used surface geophysical methods at the Texas A&M University Brazos River Hydrologic Field Research Site near College Station, Texas, in a pilot study, to characterize the hydrostratigraphic properties of the Brazos River alluvium aquifer and determine the effectiveness of the methods to aid in generating an improved ground-water availability model. Three non-invasive surface geophysical methods were used to characterize the electrical stratigraphy and hydraulic properties and to interpret the hydrostratigraphy of the Brazos River alluvium aquifer. Two methods, time-domain electromagnetic (TDEM) soundings and two-dimensional direct-current (2D-DC) resistivity imaging, were used to define the lateral and vertical extent of the Ships clay, the alluvium of the Brazos River alluvium aquifer, and the underlying Yegua Formation. Magnetic resonance sounding (MRS), a recently developed geophysical method, was used to derive estimates of the hydrologic properties including percentage water content and hydraulic conductivity. Results from the geophysics study demonstrated the usefulness of combined TDEM, 2D-DC resistivity, and MRS methods to reduce the need for additional boreholes in areas with data gaps and to provide more accurate information for ground-water availability models. Stratigraphically, the principal finding of this study is the relation between electrical resistivity and the depth and thickness of the subsurface hydrostratigraphic units at the site. TDEM data defined a three-layer electrical stratigraphy corresponding to a conductor-resistor-conductor that represents the hydrostratigraphic units - the Ships clay, the alluvium of the Brazos River alluvium aquifer, and the Yegua Formation. Sharp electrical boundaries occur at about 4 to 6 and 20 to 22 meters below land surface based on the TDEM data and define the geometry of the more resistive Brazos River alluvium aquifer

Multifractal characterization of single wall carbon nanotube thin films surface upon exposure to optical parametric oscillator laser irradiation

International Nuclear Information System (INIS)

Ţălu, Ştefan; Marković, Zoran; Stach, Sebastian; Todorović Marković, B.; Ţălu, Mihai

2014-01-01

This study presents a multifractal approach, obtained with atomic force microscopy analysis, to characterize the structural evolution of single wall carbon nanotube thin films upon exposure to optical parametric oscillator laser irradiation at wavelength of 430 nm. Microstructure and morphological changes of carbon nanotube films deposited on different substrates (mica and TGX grating) were recorded by atomic force microscope. A detailed methodology for surface multifractal characterization, which may be applied for atomic force microscopy data, was presented. Multifractal analysis of surface roughness revealed that carbon nanotube films surface has a multifractal geometry at various magnifications. The generalized dimension D q and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of carbon nanotube films surface morphology at nanometer scale. Multifractal analysis provides different yet complementary information to that offered by traditional surface statistical parameters.

Waste Characterization Methods

Energy Technology Data Exchange (ETDEWEB)

Vigil-Holterman, Luciana R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Naranjo, Felicia Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-02-02

This report discusses ways to classify waste as outlined by LANL. Waste Generators must make a waste determination and characterize regulated waste by appropriate analytical testing or use of acceptable knowledge (AK). Use of AK for characterization requires several source documents. Waste characterization documentation must be accurate, sufficient, and current (i.e., updated); relevant and traceable to the waste stream’s generation, characterization, and management; and not merely a list of information sources.

Waste Characterization Methods

International Nuclear Information System (INIS)

Vigil-Holterman, Luciana R.; Naranjo, Felicia Danielle

2016-01-01

This report discusses ways to classify waste as outlined by LANL. Waste Generators must make a waste determination and characterize regulated waste by appropriate analytical testing or use of acceptable knowledge (AK). Use of AK for characterization requires several source documents. Waste characterization documentation must be accurate, sufficient, and current (i.e., updated); relevant and traceable to the waste stream's generation, characterization, and management; and not merely a list of information sources.

Principais métodos de caracterização da porosidade de resinas à base de divinilbenzeno The most important methods for the characterization of porosity of styrene-divinylbenzene based resins

Directory of Open Access Journals (Sweden)

Viviane Gomes Teixeira

2001-12-01

Full Text Available This paper reviews the most important methods used to characterize the porosity of styrene-divinylbenzene resins. Methods such as adsorption of nitrogen for determination of surface area and mercury intrusion porosimetry for characterization of pore size distribution are related.

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.

Characterization of a surface modified carbon cryogel and a carbon supported Pt catalyst

Directory of Open Access Journals (Sweden)

BILJANA M. BABIĆ

2007-08-01

Full Text Available A carbon cryogel, synthesized by carbonization of a resorcinol/formaldehyde cryogel and oxidized in nitric acid, was used as catalyst support for Pt nano-particles. The Pt/C catalyst was prepared by a modified polyol synthesis method in an ethylene glycol (EG solution. Characterization by nitrogen adsorption showed that the carbon cryogel support and the Pt/C catalyst were mesoporous materials with high specific surface areas (SBET > 400 m2 g-1 and large mesoporous volumes. X-Ray diffraction of the catalyst demonstrated the successful reduction of the Pt precursor to metallic form. TEM Images of the Pt/C catalyst and Pt particle size distribution showed that the mean Pt particle size was about 3.3 nm. Cyclic voltammetry (CV experiments at various scan rates (from 2 to 200 mV s-1 were performed in 0.5 mol dm-3 HClO4 solution. The large capacitance of the oxidized carbon cryogel electrode, which arises from a combination of the double-layer capacitance and pseudocapacitance, associated with the participation of surface redox-type reactions was demonstrated. For the oxidized carbon cryogel, the total specific capacitance determined by 1/C vs. ν0.5 extrapolation method was found to be 386 F g-1. The hydrogen oxidation reaction at the investigated Pt/C catalyst proceeded as an electrochemically reversible, two-electron direct discharge reaction.

Surface characterization of weathered wood using a laser scanning system

International Nuclear Information System (INIS)

Arnold, M.; Lemaster, R.L.; Dost, W.A.

1992-01-01

Most of the existing methods to assess the effect of weathering on wood surfaces have some drawbacks that limit their use to specific tasks. The amount of surface erosion is often used as a measure for the weathering action. The application of a laser scanning system to reproduce surface profiles and to measure weathering erosion was tested on various samples and was found to be a very useful and superior alternative to existing methods. Further improvements of the system used can be made by refinements of the calibration procedures and by more comprehensive profile analyses. (author)

An eddy covariance system to characterize the atmospheric surface layer and turbulent latent heat fluxes over a debris-covered Himalayan glacier.

Science.gov (United States)

Litt, Maxime; Steiner, Jakob F.; Stigter, Emmy E.; Immerzeel, Walter; Shea, Joseph Michael

2017-04-01

Over debris-covered glaciers, water content variations in the debris layer can drive significant changes in its thermal conductivity and significantly impact melt rates. Since sublimation and evaporation are favoured in high-altitude conditions, e.g., low atmospheric pressure and high wind speeds, they are expected to strongly influence the water balance of the debris-layer. Dedicated latent heat fluxes measurements at the debris surface are essential to characterize the debris heat conductivity in order to assess underlying ice melt. Furthermore, the contribution of the turbulent fluxes in the surface energy balance over debris covered glacier remains uncertain since they are generally evaluated through similarity methods which might not be valid in complex terrain. We present the first results of a 15-day eddy-covariance experiment installed at the end of the monsoon (September-October) on a 3-m tower above the debris-covered Lirung glacier in Nepal. The tower also included measurements of the 4 radiation components. The eddy covariance measurements allowed for the characterization of the turbulence in the atmospheric surface layer, as well as the direct measurements of evaporation, sublimation and turbulent sensible heat fluxes. The experiment helps us to evaluate the contribution of turbulent fluxes to the surface energy balance over this debris-covered glacier, through a precise characterization of the overlying turbulent atmospheric surface layer. It also helps to study the role of the debris-layer water content changes through evaporation and sublimation and its feedback on heat conduction in this layer. The large observed turbulent fluxes play a significant role in the energy balance at the debris surface and significantly influence debris moisture, conductivity and subsequently underlying ice melt.

Numerical methods for characterization of synchrotron radiation based on the Wigner function method

Directory of Open Access Journals (Sweden)

Takashi Tanaka

2014-06-01

Full Text Available Numerical characterization of synchrotron radiation based on the Wigner function method is explored in order to accurately evaluate the light source performance. A number of numerical methods to compute the Wigner functions for typical synchrotron radiation sources such as bending magnets, undulators and wigglers, are presented, which significantly improve the computation efficiency and reduce the total computation time. As a practical example of the numerical characterization, optimization of betatron functions to maximize the brilliance of undulator radiation is discussed.

Field emission from the surface of highly ordered pyrolytic graphite

Energy Technology Data Exchange (ETDEWEB)

Knápek, Alexandr, E-mail: knapek@isibrno.cz [Institute of Scientific Instruments of the ASCR, v.v.i., Královopolská 147, Brno (Czech Republic); Sobola, Dinara; Tománek, Pavel [Department of Physics, FEEC, Brno University of Technology, Technická 8, Brno (Czech Republic); Pokorná, Zuzana; Urbánek, Michal [Institute of Scientific Instruments of the ASCR, v.v.i., Královopolská 147, Brno (Czech Republic)

2017-02-15

Highlights: • HOPG shreds were created and analyzed in the UHV conditions. • Current-voltage measurements have been done to confirm electron tunneling, based on the Fowler-Nordheim theory. • Surface was characterized by other surface evaluation methods, in particular by: SNOM, SEM and AFM. - Abstract: This paper deals with the electrical characterization of highly ordered pyrolytic graphite (HOPG) surface based on field emission of electrons. The effect of field emission occurs only at disrupted surface, i.e. surface containing ripped and warped shreds of the uppermost layers of graphite. These deformations provide the necessary field gradients which are required for measuring tunneling current caused by field electron emission. Results of the field emission measurements are correlated with other surface characterization methods such as scanning near-field optical microscopy (SNOM) or atomic force microscopy.

Field emission from the surface of highly ordered pyrolytic graphite

International Nuclear Information System (INIS)

Knápek, Alexandr; Sobola, Dinara; Tománek, Pavel; Pokorná, Zuzana; Urbánek, Michal

2017-01-01

Highlights: • HOPG shreds were created and analyzed in the UHV conditions. • Current-voltage measurements have been done to confirm electron tunneling, based on the Fowler-Nordheim theory. • Surface was characterized by other surface evaluation methods, in particular by: SNOM, SEM and AFM. - Abstract: This paper deals with the electrical characterization of highly ordered pyrolytic graphite (HOPG) surface based on field emission of electrons. The effect of field emission occurs only at disrupted surface, i.e. surface containing ripped and warped shreds of the uppermost layers of graphite. These deformations provide the necessary field gradients which are required for measuring tunneling current caused by field electron emission. Results of the field emission measurements are correlated with other surface characterization methods such as scanning near-field optical microscopy (SNOM) or atomic force microscopy.

Development of subsurface characterization method for decommissioning site remediation

Energy Technology Data Exchange (ETDEWEB)

Hong, Sang Bum; Nam, Jong Soo; Choi, Yong Suk; Seo, Bum Kyoung; Moon, Jei Kwon; Choi, Jong Won [KAERI, Daejeon (Korea, Republic of)

2016-05-15

In situ measurement of peak to valley method based on the ratio of counting rate between the full energy peak and Compton region was applied to identify the depth distribution of 137Cs. The In situ measurement and sampling results were applied to evaluate a residual radioactivity before and after remediation in decommissioning KRR site. Spatial analysis based on the Geostatistics method provides a reliable estimating the volume of contaminated soil with a graphical analysis, which was applied to the site characterization in the decommissioning KRR site. The in situ measurement and spatial analysis results for characterization of subsurface contamination are presented. The objective of a remedial action is to reduce risks to human health to acceptable levels by removing the source of contamination. Site characterization of the subsurface contamination is an important factor for planning and implementation of site remediation. Radiological survey and evaluation technology are required to ensure the reliability of the results, and the process must be easily applied during field measurements. In situ gamma-ray spectrometry is a powerful method for site characterization that can be used to identify the depth distribution and quantify radionuclides directly at the measurement site. The in situ measurement and Geostatistics method was applied to the site characterization for remediation and final status survey in decommissioning KRR site.

Soil characterization methods for unsaturated low-level waste sites

International Nuclear Information System (INIS)

Wierenga, P.J.; Young, M.H.; Hills, R.G.

1993-01-01

To support a license application for the disposal of low-level radioactive waste (LLW), applicants must characterize the unsaturated zone and demonstrate that waste will not migrate from the facility boundary. This document provides a strategy for developing this characterization plan. It describes principles of contaminant flow and transport, site characterization and monitoring strategies, and data management. It also discusses methods and practices that are currently used to monitor properties and conditions in the soil profile, how these properties influence water and waste migration, and why they are important to the license application. The methods part of the document is divided into sections on laboratory and field-based properties, then further subdivided into the description of methods for determining 18 physical, flow, and transport properties. Because of the availability of detailed procedures in many texts and journal articles, the reader is often directed for details to the available literature. References are made to experiments performed at the Las Cruces Trench site, New Mexico, that support LLW site characterization activities. A major contribution from the Las Cruces study is the experience gained in handling data sets for site characterization and the subsequent use of these data sets in modeling studies

III-V semiconductors for photoelectrochemical applications: surface preparation and characterization

Energy Technology Data Exchange (ETDEWEB)

Fertig, Dominic; Schaechner, Birgit; Calvet, Wofram; Kaiser, Bernhard; Jaegermann, Wolfram [TU Darmstadt, Fachbereich Materialwissenschaft, Fachgebiet Oberflaechenforschung (Germany)

2011-07-01

III-V semiconductors are promising reference systems for photoelectrochemical energy conversion. Therefore we have studied the influence of different acids and acidic solutions on the etching of p-doped gallium-arsenide and gallium-phosphide single crystal surfaces. From our experiments we conclude, that etching with HCl and subsequent annealing up to 450 C gives the best results for the removal of the carbonates and the oxides without affecting the quality of the sample. By treating the surfaces with ''piranha''-solution (H{sub 2}SO{sub 4}:H{sub 2}O{sub 2}:H{sub 2}O/7:2:1), the creation of an oxide layer with well defined thickness can be achieved. For the creation of an efficient photoelectrochemical cell, Pt nanoparticles have been deposited from solution. These surfaces are then characterized by photoelectron spectroscopy and AFM. Further electrochemical measurements try to correlate the effect of the surface cleaning and the Pt deposition on the photoactivity of the GaAs- and GaP-semiconductors.

Comparative evaluation of the three different surface treatments - conventional, laser and Nano technology methods in enhancing the surface characteristics of commercially pure titanium discs and their effects on cell adhesion: An in vitro study.

Science.gov (United States)

Vignesh; Nayar, Sanjna; Bhuminathan; Mahadevan; Santhosh, S

2015-04-01

The surface area of the titanium dental implant materials can be increased by surface treatments without altering their shape and form, thereby increasing the biologic properties of the biomaterial. A good biomaterial helps in early cell adhesion and cell signaling. In this study, the commercially pure titanium surfaces were prepared to enable machined surfaces to form a control material and to be compared with sandblasted and acid-etched surfaces, laser treated surfaces and titanium dioxide (20 nm) Nano-particle coated surfaces. The surface elements were characterized. The biocompatibility was evaluated by cell culture in vitro using L929 fibroblasts. The results suggested that the titanium dioxide Nano-particle coated surfaces had good osteoconductivity and can be used as a potential method for coating the biomaterial.

Characterization of metal additive manufacturing surfaces using synchrotron X-ray CT and micromechanical modeling

Science.gov (United States)

Kantzos, C. A.; Cunningham, R. W.; Tari, V.; Rollett, A. D.

2018-05-01

Characterizing complex surface topologies is necessary to understand stress concentrations created by rough surfaces, particularly those made via laser power-bed additive manufacturing (AM). Synchrotron-based X-ray microtomography (μ XCT) of AM surfaces was shown to provide high resolution detail of surface features and near-surface porosity. Using the CT reconstructions to instantiate a micromechanical model indicated that surface notches and near-surface porosity both act as stress concentrators, while adhered powder carried little to no load. Differences in powder size distribution had no direct effect on the relevant surface features, nor on stress concentrations. Conventional measurements of surface roughness, which are highly influenced by adhered powder, are therefore unlikely to contain the information relevant to damage accumulation and crack initiation.

Characterization of etch pit formation via the Everson-etching method on CdZnTe crystal surfaces from the bulk to the nanoscale

International Nuclear Information System (INIS)

Teague, Lucile C.; Duff, Martine C.; Cadieux, James R.; Soundararajan, Raji; Shick, Charles R.; Lynn, Kelvin G.

2011-01-01

A combination of atomic force microscopy, optical microscopy, and mass spectrometry was employed to study CdZnTe crystal surface and used etchant solution following exposure of the CdZnTe crystal to the Everson etch solution. We discuss the results of these studies in relationship to the initial surface preparation methods, the performance of the crystals as radiation spectrometers, the observed etch pit densities, and the chemical mechanism of surface etching. Our results show that the surface features that are exposed to etchants result from interactions with the chemical components of the etchants as well as pre-existing mechanical polishing.

Analytical characterization using surface-enhanced Raman scattering (SERS) and microfluidic sampling

International Nuclear Information System (INIS)

Wang, Chao; Yu, Chenxu

2015-01-01

With the rapid development of analytical techniques, it has become much easier to detect chemical and biological analytes, even at very low detection limits. In recent years, techniques based on vibrational spectroscopy, such as surface enhanced Raman spectroscopy (SERS), have been developed for non-destructive detection of pathogenic microorganisms. SERS is a highly sensitive analytical tool that can be used to characterize chemical and biological analytes interacting with SERS-active substrates. However, it has always been a challenge to obtain consistent and reproducible SERS spectroscopic results at complicated experimental conditions. Microfluidics, a tool for highly precise manipulation of small volume liquid samples, can be used to overcome the major drawbacks of SERS-based techniques. High reproducibility of SERS measurement could be obtained in continuous flow generated inside microfluidic devices. This article provides a thorough review of the principles, concepts and methods of SERS-microfluidic platforms, and the applications of such platforms in trace analysis of chemical and biological analytes. (topical review)

A new systematic and quantitative approach to characterization of surface nanostructures using fuzzy logic

Science.gov (United States)

Al-Mousa, Amjed A.

Thin films are essential constituents of modern electronic devices and have a multitude of applications in such devices. The impact of the surface morphology of thin films on the device characteristics where these films are used has generated substantial attention to advanced film characterization techniques. In this work, we present a new approach to characterize surface nanostructures of thin films by focusing on isolating nanostructures and extracting quantitative information, such as the shape and size of the structures. This methodology is applicable to any Scanning Probe Microscopy (SPM) data, such as Atomic Force Microscopy (AFM) data which we are presenting here. The methodology starts by compensating the AFM data for some specific classes of measurement artifacts. After that, the methodology employs two distinct techniques. The first, which we call the overlay technique, proceeds by systematically processing the raster data that constitute the scanning probe image in both vertical and horizontal directions. It then proceeds by classifying points in each direction separately. Finally, the results from both the horizontal and the vertical subsets are overlaid, where a final decision on each surface point is made. The second technique, based on fuzzy logic, relies on a Fuzzy Inference Engine (FIE) to classify the surface points. Once classified, these points are clustered into surface structures. The latter technique also includes a mechanism which can consistently distinguish crowded surfaces from those with sparsely distributed structures and then tune the fuzzy technique system uniquely for that surface. Both techniques have been applied to characterize organic semiconductor thin films of pentacene on different substrates. Also, we present a case study to demonstrate the effectiveness of our methodology to identify quantitatively particle sizes of two specimens of gold nanoparticles of different nominal dimensions dispersed on a mica surface. A comparison

Synthesis and characterization of NiO nanoparticles by Pechini method

International Nuclear Information System (INIS)

Nascimento, A.; Ribeiro, M.A.; Costa, A.C.F.M.; Gama, L.; Bernardi, M.I.B.

2009-01-01

In recent years, ultrafine magnetic particles of NiO have attracting the attention because of its unknown behavior, enormous scientific potential and technological application. Some of its more important properties are accented magnetic moments, double dynamic exchange, quantization of wave of spin and etc. In this context, this work has for objective to synthesize and to characterize nanoparticles of NiO for the Pechini method. The powder was analyzed by X-rays diffraction. The results of scanning electron microscopy, adsorption of nitrogen. The analysis of X-rays diffraction of the sample showed single-phase peaks of NiO, with crystallite size close to 38 nm. The surface area was 6.44 m 2 /g. The image from scanning electron microscopy shows soft homogeneous agglomerates. The Pechini synthesis was efficient in the production of powders of NiO nano metrics and single-phase. (author)

Surface characterization of polyethylene terephthalate films treated by ammonia low-temperature plasma

International Nuclear Information System (INIS)

Zheng Zhiwen; Ren Li; Feng Wenjiang; Zhai Zhichen; Wang Yingjun

2012-01-01

In order to study the surface characterization and protein adhesion behavior of polyethylene terephthalate film, low temperature ammonia plasma was used to modify the film. Effects of plasma conditions of the surface structures and properties were investigated. Results indicated that surface hydrophilicity of polyethylene terephthalate was significantly improved by ammonia plasma treatment. Ammonia plasma played the role more important than air treatment in the process of modification. Furthermore, by Fourier Transform Infrared spectra some new bonds such as -N=O and N-H which could result in the improvement of the surface hydrophilicity were successfully grafted on the film surface. Atom force microscope experiments indicated that more protein adsorbed on hydrophobic surfaces than hydrophilic ones, and the blobs arranged in a straight line at etching surface by plasma. Modified membrane after ammonia plasma treatment had a good cell affinity and could be effective in promoting the adhesion and growth of cells on the material surface. Timeliness experiments showed that the plasma treatment gave the material a certain performance only in a short period of time and the hydrophobicity recovered after 12 days.

Statistical analysis of surface lineaments and fractures for characterizing naturally fractured reservoirs

Energy Technology Data Exchange (ETDEWEB)

Guo, Genliang; George, S.A.; Lindsey, R.P.

1997-08-01

Thirty-six sets of surface lineaments and fractures mapped from satellite images and/or aerial photos from parts of the Mid-continent and Colorado Plateau regions were collected, digitized, and statistically analyzed in order to obtain the probability distribution functions of natural fractures for characterizing naturally fractured reservoirs. The orientations and lengths of the surface linear features were calculated using the digitized coordinates of the two end points of each individual linear feature. The spacing data of the surface linear features within an individual set were, obtained using a new analytical sampling technique. Statistical analyses were then performed to find the best-fit probability distribution functions for the orientation, length, and spacing of each data set. Twenty-five hypothesized probability distribution functions were used to fit each data set. A chi-square goodness-of-fit test was used to rank the significance of each fit. A distribution which provides the lowest chi-square goodness-of-fit value was considered the best-fit distribution. The orientations of surface linear features were best-fitted by triangular, normal, or logistic distributions; the lengths were best-fitted by PearsonVI, PearsonV, lognormal2, or extreme-value distributions; and the spacing data were best-fitted by lognormal2, PearsonVI, or lognormal distributions. These probability functions can be used to stochastically characterize naturally fractured reservoirs.

National Nanotechnology Laboratory (LNNano) open facilities for scientific community: new methods for polymeric materials characterization; Instalacoes abertas a comunidade cientifica no Laboratorio Nacional de Nanotecnologia (LNNano): novos metodos de caracterizacao de materiais polimericos

Energy Technology Data Exchange (ETDEWEB)

Silva, Cristiane A.; Santos, Ramon H.Z. dos; Bernardes, Juliana S.; Gouveia, Rubia F., E-mail: rubia.gouveia@lnnano.cnpem.br [Centro Nacional de Pesquisa em Energia e Materiais (LNNano/CNPEM), Campinas, SP (Brazil). Laboratorio Nacional de Nanotecnologia

2015-07-01

National Nanotechnology Laboratory (LNNano) at the National Center for Energy and Materials (CNPEM) presents open facilities for scientific public in some areas. In this work will be discussed the facilities for mainly the polymeric community, as well as new methods for the characterization. Low density polyethylene (LDPE) surfaces were characterized by X-ray microtomography and X-ray photoelectron spectroscopy (XPS). The results obtained by microtomography have shown that these surfaces present different contrasts when compared with the bulk. These differences are correlated with the formation of an oxidized layer at the polymer surface, which consequently have a greater X-ray attenuation. This hypothesis is confirmed by XPS, which shows LDPE surface layers are richer in carbonyl, carboxyl and vinyl groups than the bulk. This work presents that microtomography can be used as a new method for detection and characterization of polymer surface oxidation. (author)

A New Method to Simulate Free Surface Flows for Viscoelastic Fluid

Directory of Open Access Journals (Sweden)

Yu Cao

2015-01-01

Full Text Available Free surface flows arise in a variety of engineering applications. To predict the dynamic characteristics of such problems, specific numerical methods are required to accurately capture the shape of free surface. This paper proposed a new method which combined the Arbitrary Lagrangian-Eulerian (ALE technique with the Finite Volume Method (FVM to simulate the time-dependent viscoelastic free surface flows. Based on an open source CFD toolbox called OpenFOAM, we designed an ALE-FVM free surface simulation platform. In the meantime, the die-swell flow had been investigated with our proposed platform to make a further analysis of free surface phenomenon. The results validated the correctness and effectiveness of the proposed method for free surface simulation in both Newtonian fluid and viscoelastic fluid.

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.

Characterization of the March 2017 tank 10 surface sample (combination of HTF-10-17-30 AND HTF-10-17-31) and variable depth sample (combination of HTF-10-17-32 and HTF-10-17-33)

Energy Technology Data Exchange (ETDEWEB)

Reboul, S. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-07-19

Two surface samples (HTF-10-17-30 and HTF-10-17-31) and two variable depth samples (HTF-10-17-32 and HTF-10-17-33) were collected from SRS Tank 10 during March 2017 and submitted to SRNL for characterization. At SRNL, the two surface samples were combined in one container, the two variable depth samples (VDSs) were combined in another container, and then the two composite samples were each characterized by a series of physical, ionic, radiological, and elemental analysis methods. The surface sample composite was characterized primarily for Tank Farm corrosion control purposes, while the VDS composite was characterized primarily for Tank Closure Cesium Removal (TCCR) purposes.

Microstructure Characterization and Hardness Evaluation of Alloy 52 Welded Stainless Steel 316 Subjected to Ultrasonic Nanocyrtal Surface Modification Technique

Energy Technology Data Exchange (ETDEWEB)

Kim, H. D.; Amanov, A.; Pyun, Y. S. [Sun Moon Univ., Asan (Korea, Republic of); Kim, Y. S.; Choi, Y. S. [Andong National Univ., Andong (Korea, Republic of)

2015-10-15

In this study, an ultrasonic nanocrystal surface modification (UNSM) technique was applied to dissimilar weld point between STS316L and Alloy 52. This UNSM technique is a patented technology, which can be described as a type of ultrasonic cold-forging technology. It has been demonstrated that the UNSM technique is a simple method to produce a nanocrystalline surface layer at the top surface of metallic materials. Microstructure and hardness of STS316L and Alloy 52 are investigated before and after UNSM treatment. It is expected according to the previous study that the UNSM technique is able to release the residual stress which delays PWSCC. In this study, microstructural characterization and hardness evaluation of STS316L and welded Alloy 52 subjected to UNSM technique were investigated.

An Intelligent Method for Structural Reliability Analysis Based on Response Surface

Institute of Scientific and Technical Information of China (English)

桂劲松; 刘红; 康海贵

2004-01-01

As water depth increases, the structural safety and reliability of a system become more and more important and challenging. Therefore, the structural reliability method must be applied in ocean engineering design such as offshore platform design. If the performance function is known in structural reliability analysis, the first-order second-moment method is often used. If the performance function could not be definitely expressed, the response surface method is always used because it has a very clear train of thought and simple programming. However, the traditional response surface method fits the response surface of quadratic polynomials where the problem of accuracy could not be solved, because the true limit state surface can be fitted well only in the area near the checking point. In this paper, an intelligent computing method based on the whole response surface is proposed, which can be used for the situation where the performance function could not be definitely expressed in structural reliability analysis. In this method, a response surface of the fuzzy neural network for the whole area should be constructed first, and then the structural reliability can be calculated by the genetic algorithm. In the proposed method, all the sample points for the training network come from the whole area, so the true limit state surface in the whole area can be fitted. Through calculational examples and comparative analysis, it can be known that the proposed method is much better than the traditional response surface method of quadratic polynomials, because, the amount of calculation of finite element analysis is largely reduced, the accuracy of calculation is improved,and the true limit state surface can be fitted very well in the whole area. So, the method proposed in this paper is suitable for engineering application.

Nowcasting Surface Meteorological Parameters Using Successive Correction Method

National Research Council Canada - National Science Library

Henmi, Teizi

2002-01-01

The successive correction method was examined and evaluated statistically as a nowcasting method for surface meteorological parameters including temperature, dew point temperature, and horizontal wind vector components...

Synthesis, Characterization, Topographical Modification, and Surface Properties of Copoly(Imide Siloxane)s

Science.gov (United States)

Wohl, Christopher J.; Atkins, Brad M.; Belcher, Marcus A.; Connell, John W.

2012-01-01

Novel copoly(imide siloxane)s were synthesized from commercially available aminopropyl terminated siloxane oligomers, aromatic dianhydrides, and diamines. This synthetic approach produced copolymers with well-defined siloxane blocks linked with imide units in a random fashion. The copoly(amide acid)s were characterized by solution viscosity and subsequently used to cast thin films followed by thermal imidization in an inert atmosphere. Thin films were characterized using contact angle goniometry, attenuated total reflection Fourier transform infrared spectroscopy, confocal and optical microscopy, and tensile testing. Adhesion of micronsized particles was determined quantitatively using a sonication device. The polydimethylsiloxane (PDMS) moieties lowered the copolymer surface energy due to migration of siloxane moieties to the film s surface, resulting in a notable reduction in particle adhesion. A further reduction in particle adhesion was achieved by introducing topographical features on a scale of several to tens of microns by a laser ablation technique.

Performance Assessment of Low-Noise Road Surfaces in the Leopoldo Project: Comparison and Validation of Different Measurement Methods

Directory of Open Access Journals (Sweden)

Gaetano Licitra

2015-01-01

Full Text Available In almost all urban contexts and in many extra-urban conurbations, where road traffic is the main noise pollution source, the use of barriers is not allowed. In these cases, low-noise road surfaces are the most used mitigation action together with traffic flow reduction. Selecting the optimal surface is only the first problem that the public administration has to face. In the second place, it has to consider the issue of assessing the efficacy of the mitigation action. The purpose of the LEOPOLDO project was to improve the knowledge in the design and the characterization of low-noise road surfaces, producing guidelines helpful to the public administrations. Several experimental road surfaces were tested. Moreover, several measurement methods were implemented aiming to select those that are suitable for a correct assessment of the pavement performances laid as mitigation planning. In this paper, the experience gained in the LEOPOLDO project will be described, focusing on both the measurement methods adopted to assess the performance of a low-noise road surface and the criteria by which the experimental results have to be evaluated, presenting a comparison of the obtained results and their monitoring along time.

Morpho-chemical characterization and surface properties of carcinogenic zeolite fibers.

Science.gov (United States)

Mattioli, Michele; Giordani, Matteo; Dogan, Meral; Cangiotti, Michela; Avella, Giuseppe; Giorgi, Rodorico; Dogan, A Umran; Ottaviani, Maria Francesca

2016-04-05

Erionite belonging to the zeolite family is a human health-hazard, since it was demonstrated to be carcinogenic. Conversely, offretite family zeolites were suspected carcinogenic. Mineralogical, morphological, chemical, and surface characterizations were performed on two erionites (GF1, MD8) and one offretite (BV12) fibrous samples and, for comparison, one scolecite (SC1) sample. The specific surface area analysis indicated a larger availability of surface sites for the adsorption onto GF1, while SC1 shows the lowest one and the presence of large pores in the poorly fibrous zeolite aggregates. Selected spin probes revealed a high adsorption capacity of GF1 compared to the other zeolites, but the polar/charged interacting sites were well distributed, intercalated by less polar sites (Si-O-Si). MD8 surface is less homogeneous and the polar/charged sites are more interacting and closer to each other compared to GF1. The interacting ability of BV12 surface is much lower than that found for GF1 and MD8 and the probes are trapped in small pores into the fibrous aggregates. In comparison with the other zeolites, the non-carcinogenic SC1 shows a poor interacting ability and a lower surface polarity. These results helped to clarify the chemical properties and the surface interacting ability of these zeolite fibers which may be related to their carcinogenicity. Copyright © 2015 Elsevier B.V. All rights reserved.

Computational efficiency for the surface renewal method

Science.gov (United States)

Kelley, Jason; Higgins, Chad

2018-04-01

Measuring surface fluxes using the surface renewal (SR) method requires programmatic algorithms for tabulation, algebraic calculation, and data quality control. A number of different methods have been published describing automated calibration of SR parameters. Because the SR method utilizes high-frequency (10 Hz+) measurements, some steps in the flux calculation are computationally expensive, especially when automating SR to perform many iterations of these calculations. Several new algorithms were written that perform the required calculations more efficiently and rapidly, and that tested for sensitivity to length of flux averaging period, ability to measure over a large range of lag timescales, and overall computational efficiency. These algorithms utilize signal processing techniques and algebraic simplifications that demonstrate simple modifications that dramatically improve computational efficiency. The results here complement efforts by other authors to standardize a robust and accurate computational SR method. Increased speed of computation time grants flexibility to implementing the SR method, opening new avenues for SR to be used in research, for applied monitoring, and in novel field deployments.

Characterization of Natural Dyes and Traditional Korean Silk Fabric by Surface Analytical Techniques

Directory of Open Access Journals (Sweden)

Yeonhee Lee

2013-05-01

Full Text Available Time-of-flight secondary ion mass spectrometry (TOF-SIMS and X-ray photoelectron spectroscopy (XPS are well established surface techniques that provide both elemental and organic information from several monolayers of a sample surface, while also allowing depth profiling or image mapping to be carried out. The static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric and biological materials. In this work, TOF-SIMS, XPS and Fourier Transform Infrared (FTIR measurements were used to characterize commercial natural dyes and traditional silk fabric dyed with plant extracts dyes avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. Silk textiles dyed with plant extracts were then analyzed for chemical and functional group identification of their dye components and mordants. TOF-SIMS spectra for the dyed silk fabric showed element ions from metallic mordants, specific fragment ions and molecular ions from plant-extracted dyes. The results of TOF-SIMS, XPS and FTIR are very useful as a reference database for comparison with data about traditional Korean silk fabric and to provide an understanding of traditional dyeing materials. Therefore, this study shows that surface techniques are useful for micro-destructive analysis of plant-extracted dyes and Korean dyed silk fabric.

Characterization of Natural Dyes and Traditional Korean Silk Fabric by Surface Analytical Techniques

Science.gov (United States)

Lee, Jihye; Kang, Min Hwa; Lee, Kang-Bong; Lee, Yeonhee

2013-01-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) are well established surface techniques that provide both elemental and organic information from several monolayers of a sample surface, while also allowing depth profiling or image mapping to be carried out. The static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric and biological materials. In this work, TOF-SIMS, XPS and Fourier Transform Infrared (FTIR) measurements were used to characterize commercial natural dyes and traditional silk fabric dyed with plant extracts dyes avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. Silk textiles dyed with plant extracts were then analyzed for chemical and functional group identification of their dye components and mordants. TOF-SIMS spectra for the dyed silk fabric showed element ions from metallic mordants, specific fragment ions and molecular ions from plant-extracted dyes. The results of TOF-SIMS, XPS and FTIR are very useful as a reference database for comparison with data about traditional Korean silk fabric and to provide an understanding of traditional dyeing materials. Therefore, this study shows that surface techniques are useful for micro-destructive analysis of plant-extracted dyes and Korean dyed silk fabric. PMID:28809257

Nuclear microprobe characterization of surface hardening by precipitation of chromium carbides after laser beam treatment of a Ni-Cr substrate

International Nuclear Information System (INIS)

Mosbah, M.; Gosset, J.; Trocellier, P.; Puig, T.; Cantarel, M.; Condat, M.

1989-01-01

Surface treatment by laser provides interesting solutions to the problem of accelerated wear of materials. The aim of the present study is the characterization of chromium carbides rich surface alloys after laser beam melting of a Ni 70 Cr 30 carbon precoated substrate. The carbon profiling of the lasered surface was performed by nuclear microprobe using the 12 C(d,p 0 ) 13 C reaction, Ni and Cr were evaluated by means of PIXE (Particle Induced X Ray Emission). The specificity of the method and the experimental conditions are explained. Wear results are very satisfactory and close to those obtained by injection of chromium carbide powders into the laser beam in the case of a Nimonic alloy: wear rates are divided by two orders of magnitude

Monte Carlo method to characterize radioactive waste drums

International Nuclear Information System (INIS)

Lima, Josenilson B.; Dellamano, Jose C.; Potiens Junior, Ademar J.

2013-01-01

Non-destructive methods for radioactive waste drums characterization have being developed in the Waste Management Department (GRR) at Nuclear and Energy Research Institute IPEN. This study was conducted as part of the radioactive wastes characterization program in order to meet specifications and acceptance criteria for final disposal imposed by regulatory control by gamma spectrometry. One of the main difficulties in the detectors calibration process is to obtain the counting efficiencies that can be solved by the use of mathematical techniques. The aim of this work was to develop a methodology to characterize drums using gamma spectrometry and Monte Carlo method. Monte Carlo is a widely used mathematical technique, which simulates the radiation transport in the medium, thus obtaining the efficiencies calibration of the detector. The equipment used in this work is a heavily shielded Hyperpure Germanium (HPGe) detector coupled with an electronic setup composed of high voltage source, amplifier and multiport multichannel analyzer and MCNP software for Monte Carlo simulation. The developing of this methodology will allow the characterization of solid radioactive wastes packed in drums and stored at GRR. (author)

Development of a new method for high temperature in-core characterisation of solid surfaces

International Nuclear Information System (INIS)

Yamawaki, M.; Suzuki, A.; Yokota, T.; Nan Luo, G.; Yamaguchi, K.; Hayashi, K.

2000-01-01

In order to develop a new method for establishing in situ characterizations and monitoring of solid surfaces under irradiation and in controlled atmospheres, the high temperature Kelvin probe has been applied and tested to measure work function changes under such conditions. In the case of Li 4 SiO 4 and Li 2 ZrO 3 , two steps of distinct change of work function were observed when the specimen was exposed to hydrogen gas and also when it was retrieved. These changes were attributed to the oxygen vacancies formation/annihilation and the adsorption/desorption of gas (H 2 ). While the work function measured on a gold specimen under proton beam irradiation showed a steep drop in the work function during the initial irradiation, it gradually recovered after the end of irradiation. The second irradiation gave rise to a smaller value of the work function decrease of gold. These results support a possibility of adopting the high temperature Kelvin probe for the purpose of monitoring/characterising solid surface under irradiation in nuclear reactors and other facilities so as to detect the formation of defects in the surface and near-surface region of solid specimens. (authors)

Method of predicting surface deformation in the form of sinkholes

Energy Technology Data Exchange (ETDEWEB)

Chudek, M.; Arkuszewski, J.

1980-06-01

Proposes a method for predicting probability of sinkhole shaped subsidence, number of funnel-shaped subsidences and size of individual funnels. The following factors which influence the sudden subsidence of the surface in the form of funnels are analyzed: geologic structure of the strata between mining workings and the surface, mining depth, time factor, and geologic disolocations. Sudden surface subsidence is observed only in the case of workings situated up to a few dozen meters from the surface. Using the proposed method is explained with some examples. It is suggested that the method produces correct results which can be used in coal mining and in ore mining. (1 ref.) (In Polish)

Micro-cantilevers for non-destructive characterization of nanograss uniformity

DEFF Research Database (Denmark)

Petersen, Dirch Hjorth; Wang, Fei; Olesen, Mikkel Buster

2011-01-01

We demonstrate an application of three-way flexible micro four-point probes for indirect uniformity characterization of surface morphology. The mean sheet conductance of a quasi-planar 3D nanostructured surface is highly dependent on the surface morphology, and thus accurate sheet conductance...... measurements may be useful for process uniformity characterization. The method is applied for characterization of TiW coated nanograss uniformity. Three-way flexible L-shaped cantilever electrodes are used to avoid damage to the fragile surface, and a relative standard deviation on measurement repeatability...... of 0.12 % is obtained with a measurement yield of 97%. Finally, variations in measured sheet conductance are correlated to the surface morphology as characterized by electron microscopy....

Advances in the Surface Renewal Flux Measurement Method

Science.gov (United States)

Shapland, T. M.; McElrone, A.; Paw U, K. T.; Snyder, R. L.

2011-12-01

The measurement of ecosystem-scale energy and mass fluxes between the planetary surface and the atmosphere is crucial for understanding geophysical processes. Surface renewal is a flux measurement technique based on analyzing the turbulent coherent structures that interact with the surface. It is a less expensive technique because it does not require fast-response velocity measurements, but only a fast-response scalar measurement. It is therefore also a useful tool for the study of the global cycling of trace gases. Currently, surface renewal requires calibration against another flux measurement technique, such as eddy covariance, to account for the linear bias of its measurements. We present two advances in the surface renewal theory and methodology that bring the technique closer to becoming a fully independent flux measurement method. The first advance develops the theory of turbulent coherent structure transport associated with the different scales of coherent structures. A novel method was developed for identifying the scalar change rate within structures at different scales. Our results suggest that for canopies less than one meter in height, the second smallest coherent structure scale dominates the energy and mass flux process. Using the method for resolving the scalar exchange rate of the second smallest coherent structure scale, calibration is unnecessary for surface renewal measurements over short canopies. This study forms the foundation for analysis over more complex surfaces. The second advance is a sensor frequency response correction for measuring the sensible heat flux via surface renewal. Inexpensive fine-wire thermocouples are frequently used to record high frequency temperature data in the surface renewal technique. The sensible heat flux is used in conjunction with net radiation and ground heat flux measurements to determine the latent heat flux as the energy balance residual. The robust thermocouples commonly used in field experiments

Characterization of Tar Deposits, Extraction and Sorption Properties

Directory of Open Access Journals (Sweden)

Pryszcz Adrian

2016-06-01

Full Text Available The main goal of this paper was to characterize and find a useful solution for the decomposition of tar deposits. For the experimental part, tar deposits, formed by polymerization and condensation reactions, were chosen from a storage tank for tars. At first the initial analyses of tar deposits (elemental, thermogravimetric, and calorimetric analyses were performed. After the characterization, the tar deposits were extracted in the Soxhlet extractor by acetone, toluene, and quinolone and activated with potassium hydroxide. As the final step of this work, the sorption characterization on the 3Flex Surface Characterization Analyzer (Micromeritics was performed. The specific surface area of the samples was evaluated using two methods - a single point measurement at p/p0=0.2 and BET method. Micropore and external surface areas were calculated based on a t-plot analysis (carbon black model.

Study of fine films nature on the surface of copper band by photoelectron spectroscopy method

International Nuclear Information System (INIS)

Reznichenko, K.N.; Fedorov, V.N.; Shevakin, Yu.F.

1983-01-01

The composition of surface films formed on the copper band of industrial production under atmospheric conditions, its changes in thickness and determination of chemical state of the above films are studied. It has been found by the methods of X-ray photoelectronic and Auger-spectroscopy that defect formations on the surface of the copper band of industrial production represent copper oxides in the form of fine films, their change in colour from blue to dark blue probably is determined by different thickness of these defects. The said films on copper have practically identical chemical composition characterized by the presence of unequally valent copper, oxygen in various states (adsorbed and in the form of oxides), carbon and iron. By means of chemical shifts of the line Cu 2psub(3/2) and Ol s the presence in the external part of the film of CuO copper oxide is established and nearer to the interface surface film-metal-of Cu 2 O cuprous oxide which indicates a two-layer surface film structure. The presence of adsorbed carbon and iron in the film composition is a result of surface contamination

System and method for generating 3D images of non-linear properties of rock formation using surface seismic or surface to borehole seismic or both

Science.gov (United States)

Vu, Cung Khac; Nihei, Kurt Toshimi; Johnson, Paul A.; Guyer, Robert A.; Ten Cate, James A.; Le Bas, Pierre-Yves; Larmat, Carene S.

2016-06-07

A system and method of characterizing properties of a medium from a non-linear interaction are include generating, by first and second acoustic sources disposed on a surface of the medium on a first line, first and second acoustic waves. The first and second acoustic sources are controllable such that trajectories of the first and second acoustic waves intersect in a mixing zone within the medium. The method further includes receiving, by a receiver positioned in a plane containing the first and second acoustic sources, a third acoustic wave generated by a non-linear mixing process from the first and second acoustic waves in the mixing zone; and creating a first two-dimensional image of non-linear properties or a first ratio of compressional velocity and shear velocity, or both, of the medium in a first plane generally perpendicular to the surface and containing the first line, based on the received third acoustic wave.

Performance evaluation of sea surface simulation methods for target detection

Science.gov (United States)

Xia, Renjie; Wu, Xin; Yang, Chen; Han, Yiping; Zhang, Jianqi

2017-11-01

With the fast development of sea surface target detection by optoelectronic sensors, machine learning has been adopted to improve the detection performance. Many features can be learned from training images by machines automatically. However, field images of sea surface target are not sufficient as training data. 3D scene simulation is a promising method to address this problem. For ocean scene simulation, sea surface height field generation is the key point to achieve high fidelity. In this paper, two spectra-based height field generation methods are evaluated. Comparison between the linear superposition and linear filter method is made quantitatively with a statistical model. 3D ocean scene simulating results show the different features between the methods, which can give reference for synthesizing sea surface target images with different ocean conditions.

Characterization of SCC crack tips and surface oxide layers in alloy 600

Energy Technology Data Exchange (ETDEWEB)

Fujii, Katsuhiko; Fukuya, Koji [Inst. of Nuclear Safety System Inc., Mihama, Fukui (Japan)

2002-09-01

In order to investigate the mechanism of primary water stress corrosion cracking (SCC), direct observation of microstructures of SCC crack tips and surface oxide layers in alloy 600 were carried out. A focused-ion beam (FIB) micro-processing technique was applied to prepare electron transparent foils including the crack tip and the surface oxide layer without any damage to those microstructures. Transmission electron microscopy and analysis were used to characterize the crack tips and surface oxide layers. Cr-rich oxides and a metal-Ni phase were identified in the crack tips and grain boundaries ahead of the crack tips independent of dissolved hydrogen concentrations. >From the fact that the Cr-rich oxides and metal-Ni phase were observed in the inner surface oxide layer, the same oxidation mechanism as the surface is proposed for the crack tip region and internal oxidation accompanying selective Cr oxidation is suggested as the mechanism. (author)

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.

Morphological, Chemical Surface, and Diffusive Transport Characterizations of a Nanoporous Alumina Membrane

Directory of Open Access Journals (Sweden)

María I. Vázquez

2015-12-01

Full Text Available Synthesis of a nanoporous alumina membrane (NPAM by the two-step anodization method and its morphological and chemical surface characterization by analyzing Scanning Electron Microscopy (SEM micrographs and X-Ray Photoelectron Spectroscopy (XPS spectra is reported. Influence of electrical and diffusive effects on the NaCl transport across the membrane nanopores is determined from salt diffusion measurements performed with a wide range of NaCl concentrations, which allows the estimation of characteristic electrochemical membrane parameters such as the NaCl diffusion coefficient and the concentration of fixed charges in the membrane, by using an appropriated model and the membrane geometrical parameters (porosity and pore length. These results indicate a reduction of ~70% in the value of the NaCl diffusion coefficient through the membrane pores with respect to solution. The transport number of ions in the membrane pores (Na+ and Cl−, respectively were determined from concentration potential measurements, and the effect of concentration-polarization at the membrane surfaces was also considered by comparing concentration potential values obtained with stirred solutions (550 rpm and without stirring. From both kinds of results, a value higher than 0.05 M NaCl for the feed solution seems to be necessary to neglect the contribution of electrical interactions in the diffusive transport.

Characterization of foot- and mouth disease virus antigen by surface-enhanced laser desorption ionization-time of flight-mass spectrometry in aqueous and oil-emulsion formulations

NARCIS (Netherlands)

Harmsen, M.M.; Jansen, J.; Westra, D.F.; Coco-Martin, J.M.

2010-01-01

We have used a novel method, surface-enhanced laser desorption ionization-time of flight-mass spectrometry (SELDI-TOF-MS), to characterize foot-and-mouth disease virus (FMDV) vaccine antigens. Using specific capture with FMDV binding recombinant antibody fragments and tryptic digestion of FMDV

Characterization of chemical composition, surface area pore, and thermal properties of zeolites from Bayah, Tasikmalaya, and Lampung

International Nuclear Information System (INIS)

Ginting, Aslina Br.; Dian Anggraini; Sutri Indaryati; Rosika Kriswarini

2007-01-01

Characterization of chemical composition, surface area, pore radius, adsorption, and thermal properties of zeolites from Bayah, Tasikmalaya, and Lampung have been performed. The purpose of the characterization is to understand the characteristics of the three zeolites since different types of zeolite will yield different chemical composition, surface area, pore radius, and adsorption. The analysis shows that zeolites from Bayah, Tasikmalaya, and Lampung consist of chemical elements Al, Si, P, K, Ca, Ti, Fe, and S. The analysis of the surface area indicates that zeolite from Lampung has surface area of 10.0477 m 2 , pore radius of 16.0653 Å, and adsorption of 24.500 ml/g, which are greater than those of zeolite from Tasikmalaya with surface area of 6.3319 m2, pore radius of 16.2350 Å, adsorption of 13.2500 ml/g, zeolite from Bayah with surface area of 8.3528 m2, pore radius of 16.2350 Å, and adsorption of 13.250 ml/g. From of the thermal properties characterization it is shown the three zeolites experienced weight reduction from 5.93% to 8.33%, which results in the formation of new phases as indicated by endothermic reactions from 150 °C to 600 °C and from 850 °C to 1000 °C. The three zeolites experienced a decrease in heat capacity up to temperature of 199.96 °C, whereas at temperatures above 216.66 °C the zeolites experienced an increase in heat capacity up to 437.78 °C. The results of the characterization indicate that different types of zeolite do not yield significant difference in chemical composition and thermal characteristics as proven with F test, however different surface area, pore radius, and adsorption characteristics are observed. The characterization results are expected to be the first step in determining the characteristics of the three zeolites that are to be used for cesium ion exchange in the incoming research. (author)

Surface modification of synthetic clay aimed at biomolecule adsorption: synthesis and characterization

Directory of Open Access Journals (Sweden)

Angela de Mello Ferreira Guimarães

2007-03-01

Full Text Available This work describes the process for functionalization of laponite through the grafting of 3-mercaptopropyltrimethoxysilane (MPTS. Laponite is synthetic smectite clay with surface area of 350 m²/g. The samples, prior to and after functionalization, were characterized by chemical analyses, thermogravimetric analysis (TGA, x ray diffraction (XRD, diffuse reflectance infrared Fourier transform spectroscopy (DRIFT, scanning electron microscopy and energy dispersive spectrometry (MEV/EDS. Infrared spectroscopy and elemental analyses confirmed the presence of organic chains and thiol groups in the modified clay. The immobilized and available thiol group, measured according to the Volhard method, totaled 1.4 meq/g of clay, with approximately 90% accessible for Ag+ trapping. These results represent an improvement as compared to other works concerning the functionalization of smectite-type clays in which the effect produced by functional group blockage limits the access of species to less than 10% of the complexing sites.

The Characterization of Lithium Titanate Microspheres Synthesized by a Hydrothermal Method

Directory of Open Access Journals (Sweden)

Wei Liu

2013-01-01

Full Text Available Lithium titanate microspheres were synthesized by a hydrothermal method. The structure and morphology of samples were characterized by X-ray diffraction, infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy, respectively. The specific surface area and average pore diameter of samples were studied by N2 adsorption-desorption isotherms. The results indicated that amorphous phase changed to lithium titanium oxide hydrate, accompanying mesopores formed between agglomerated primary particles in hydrothermal reaction. After sintering, mesoporous Li4Ti5O12 microspheres assembled by nanosized particle were obtained and had a diameter of about 400–700 nm. Then, a possible formation process analogous to the Kirkendall effect was proposed. Moreover, the effect of sintering temperature on the electrochemical properties of Li4Ti5O12 microspheres was investigated.

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.

The Quantified Characterization Method of the Micro-Macro Contacts of Three-Dimensional Granular Materials on the Basis of Graph Theory.

Science.gov (United States)

Guan, Yanpeng; Wang, Enzhi; Liu, Xiaoli; Wang, Sijing; Luan, Hebing

2017-08-03

We have attempted a multiscale and quantified characterization method of the contact in three-dimensional granular material made of spherical particles, particularly in cemented granular material. Particle contact is defined as a type of surface contact with voids in its surroundings, rather than a point contact. Macro contact is a particle contact set satisfying the restrictive condition of a two-dimensional manifold with a boundary. On the basis of graph theory, two dual geometrical systems are abstracted from the granular pack. The face and the face set, which satisfies the two-dimensional manifold with a boundary in the solid cell system, are extracted to characterize the particle contact and the macro contact, respectively. This characterization method is utilized to improve the post-processing in DEM (Discrete Element Method) from a micro perspective to describe the macro effect of the cemented granular material made of spherical particles. Since the crack has the same shape as its corresponding contact, this method is adopted to characterize the crack and realize its visualization. The integral failure route of the sample can be determined by a graph theory algorithm. The contact force is assigned to the weight value of the face characterizing the particle contact. Since the force vectors can be added, the macro contact force can be solved by adding the weight of its corresponding faces.

Preparation and characterization of SnO2 thin film by chemical bath deposition method for solar cell application

International Nuclear Information System (INIS)

Wan Mohd Zin Wan Yunus; Saeideh Ebrahimiasl; Anuar Kassim

2009-01-01

Full text: Tin oxide thin films were synthesized by chemical bath deposition method on glass substrate .The as-deposited thin films were characterized for compositional, structural, surface morphological, optical and electrical properties. The X-ray diffraction patterns of the sample indicate that all samples are polycrystalline structure. AFM images show that the films consist of small uniform grains and are free of pinholes. (author)

Characterization methods for ultrasonic test systems

International Nuclear Information System (INIS)

Busse, L.J.; Becker, F.L.; Bowey, R.E.; Doctor, S.R.; Gribble, R.P.; Posakony, G.J.

1982-07-01

Methods for the characterization of ultrasonic transducers (search units) and instruments are presented. The instrument system is considered as three separate components consisting of a transducer, a receiver-display, and a pulser. The operation of each component is assessed independently. The methods presented were chosen because they provide the greatest amount of information about component operation and were not chosen based upon such conditions as cost, ease of operation, field implementation, etc. The results of evaluating a number of commercially available ultrasonic test instruments are presented

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.

Surface-treated commercially pure titanium for biomedical applications: Electrochemical, structural, mechanical and chemical characterizations

International Nuclear Information System (INIS)

Ogawa, Erika S.; Matos, Adaias O.; Beline, Thamara; Marques, Isabella S.V.; Sukotjo, Cortino; Mathew, Mathew T.; Rangel, Elidiane C.; Cruz, Nilson C.; Mesquita, Marcelo F.; Consani, Rafael X.

2016-01-01

Modified surfaces have improved the biological performance and biomechanical fixation of dental implants compared to machined (polished) surfaces. However, there is a lack of knowledge about the surface properties of titanium (Ti) as a function of different surface treatment. This study investigated the role of surface treatments on the electrochemical, structural, mechanical and chemical properties of commercial pure titanium (cp-Ti) under different electrolytes. Cp-Ti discs were divided into 6 groups (n = 5): machined (M—control); etched with HCl + H_2O_2 (Cl), H_2SO_4 + H_2O_2 (S); sandblasted with Al_2O_3 (Sb), Al_2O_3 followed by HCl + H_2O_2 (SbCl), and Al_2O_3 followed by H_2SO_4 + H_2O_2 (SbS). Electrochemical tests were conducted in artificial saliva (pHs 3; 6.5 and 9) and simulated body fluid (SBF—pH 7.4). All surfaces were characterized before and after corrosion tests using atomic force microscopy, scanning electron microscopy, energy dispersive microscopy, X-ray diffraction, surface roughness, Vickers microhardness and surface free energy. The results indicated that Cl group exhibited the highest polarization resistance (R_p) and the lowest capacitance (Q) and corrosion current density (I_c_o_r_r) values. Reduced corrosion stability was noted for the sandblasted groups. Acidic artificial saliva decreased the R_p values of cp-Ti surfaces and produced the highest I_c_o_r_r values. Also, the surface treatment and corrosion process influenced the surface roughness, Vickers microhardness and surface free energy. Based on these results, it can be concluded that acid-etching treatment improved the electrochemical stability of cp-Ti and all treated surfaces behaved negatively in acidic artificial saliva. - Highlights: • Characterization of surface treatment for biomedical implants was investigated. • Sandblasting reduced the corrosion stability of cp-Ti. • Acid etching is a promising dental implants surface treatment.

Surface-treated commercially pure titanium for biomedical applications: Electrochemical, structural, mechanical and chemical characterizations

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Erika S.; Matos, Adaias O.; Beline, Thamara [Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Av Limeira, 901, Piracicaba, São Paulo 13414-903 (Brazil); IBTN/Br—Institute of Biomaterials, Tribocorrosion and Nanomedicine—Brazilian Branch (Brazil); Marques, Isabella S.V. [Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Av Limeira, 901, Piracicaba, São Paulo 13414-903 (Brazil); Sukotjo, Cortino [Department of Restorative Dentistry, University of Illinois at Chicago, College of Dentistry, 801 S Paulina, Chicago, IL, USA, 60612 (United States); IBTN—Institute of Biomaterials, Tribocorrosion and Nanomedicine (United States); Mathew, Mathew T. [IBTN—Institute of Biomaterials, Tribocorrosion and Nanomedicine (United States); Department of Biomedical Sciences, University of Illinois, College of Medicine at Rockford, 1601 Parkview Avenue, Rockford, IL, USA, 61107 (United States); Rangel, Elidiane C.; Cruz, Nilson C. [IBTN/Br—Institute of Biomaterials, Tribocorrosion and Nanomedicine—Brazilian Branch (Brazil); Laboratory of Technological Plasmas, Engineering College, Univ Estadual Paulista (UNESP), Av Três de Março, 511, Sorocaba, São Paulo 18087-180 (Brazil); Mesquita, Marcelo F.; Consani, Rafael X. [Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Av Limeira, 901, Piracicaba, São Paulo 13414-903 (Brazil); and others

2016-08-01

Modified surfaces have improved the biological performance and biomechanical fixation of dental implants compared to machined (polished) surfaces. However, there is a lack of knowledge about the surface properties of titanium (Ti) as a function of different surface treatment. This study investigated the role of surface treatments on the electrochemical, structural, mechanical and chemical properties of commercial pure titanium (cp-Ti) under different electrolytes. Cp-Ti discs were divided into 6 groups (n = 5): machined (M—control); etched with HCl + H{sub 2}O{sub 2} (Cl), H{sub 2}SO{sub 4} + H{sub 2}O{sub 2} (S); sandblasted with Al{sub 2}O{sub 3} (Sb), Al{sub 2}O{sub 3} followed by HCl + H{sub 2}O{sub 2} (SbCl), and Al{sub 2}O{sub 3} followed by H{sub 2}SO{sub 4} + H{sub 2}O{sub 2} (SbS). Electrochemical tests were conducted in artificial saliva (pHs 3; 6.5 and 9) and simulated body fluid (SBF—pH 7.4). All surfaces were characterized before and after corrosion tests using atomic force microscopy, scanning electron microscopy, energy dispersive microscopy, X-ray diffraction, surface roughness, Vickers microhardness and surface free energy. The results indicated that Cl group exhibited the highest polarization resistance (R{sub p}) and the lowest capacitance (Q) and corrosion current density (I{sub corr}) values. Reduced corrosion stability was noted for the sandblasted groups. Acidic artificial saliva decreased the R{sub p} values of cp-Ti surfaces and produced the highest I{sub corr} values. Also, the surface treatment and corrosion process influenced the surface roughness, Vickers microhardness and surface free energy. Based on these results, it can be concluded that acid-etching treatment improved the electrochemical stability of cp-Ti and all treated surfaces behaved negatively in acidic artificial saliva. - Highlights: • Characterization of surface treatment for biomedical implants was investigated. • Sandblasting reduced the corrosion stability of cp

Surface characterization of superconductive Nd1Ba2Cu3Oy thin films using scanning probe microscopes

International Nuclear Information System (INIS)

Ting, W.; Badaye, M.; Itti, R.; Morishita, T.; Koshizuka, N.; Tanaka, S.

1996-01-01

Recently, superconductive Nd 1 Ba 2 Cu 3 O y (Nd123) thin films with high superconducting transition temperature (T c ) have been successfully fabricated at the authors institute employing the standard laser ablation method. In this paper, they report parts of the results of surface characterization of the Nd123 thin films using an ultrahigh vacuum scanning tunneling microscope/spectroscopy (UHV-STM/STS) and an atomic force microscope (AFM) system operated in air. Clear spiral pattern is observed on the surfaces of Nd123 thin films by STM and AFM, suggesting that films are formed by two-dimensional island growth mode at the final growing stage. Contour plots of the spirals show that the step heights of the spirals are not always the integer or half integer numbers of the c-axis parameter of the structure. This implies that the surface natural termination layer of the films may not be unique. Surface atomic images of the as-prepared Nd123 thin films are obtained employing both STM and AFM. STS measurements show that most of the surfaces are semiconductive, or sometimes even metallic. The results of STS measurements together with the fact that they are able to see the surface atomic images using scanning probe microscopes suggest that exposure to air does not cause serious degradation to the as-prepared surfaces of Nd123 thin films

Investigation on the surface characterization of Ga-faced GaN after chemical-mechanical polishing

Energy Technology Data Exchange (ETDEWEB)

Gong, Hua [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Shenzhen Key Laboratory of Micro/nano Manufacturing, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Pan, Guoshun, E-mail: pangs@tsinghua.edu.cn [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Shenzhen Key Laboratory of Micro/nano Manufacturing, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Zhou, Yan; Shi, Xiaolei; Zou, Chunli; Zhang, Suman [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Shenzhen Key Laboratory of Micro/nano Manufacturing, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China)

2015-05-30

Highlights: • Tiny-sized nanoparticles were introduced in GaN CMP to realize a good surface. • The relationship between surface characterization and abrasive size was conducted. • An atomic step-terrace structure was achieved on GaN surface after CMP. • Pt/C catalyst nanoparticles were used in GaN CMP to get a higher MRR. - Abstract: The relationship between the surface characterization after chemical mechanical polishing (CMP) and the size of the silica (SiO{sub 2}) abrasive used for CMP of gallium nitride (GaN) substrates was investigated in detail. Atomic force microscope was used for measuring the surface morphology, pit feature, pit depth distribution, and atomic step-terrace structure. With the decrease of SiO{sub 2} abrasive size, the pit depth reduced and the atomic step-terrace structure became more whole with smaller damage area, resulting in smaller roughness. For tiny-sized SiO{sub 2} abrasive, an almost complete atomic step-terrace structure with 0.0523 nm roughness was achieved. On the other hand, in order to acquire higher removal, Pt/C nanoparticle was employed as a catalyst in CMP slurry. The result indicates that when Pt/C catalyst content was reached to 1.0 ppm, material removal rate was increased by 47.69% compared to that by none of the catalyst, and besides, the pit depth reduced and the surface atomic step-terrace structure was not destroyed. The Pt/C nanoparticle is proved to be the promising catalyst to the surface preparation of super-hard and inert materials with high efficiency and good surface.

Stem mortality in surface fires: Part II, experimental methods for characterizing the thermal response of tree stems to heating by fires

Science.gov (United States)

D. M. Jimenez; B. W. Butler; J. Reardon

2003-01-01

Current methods for predicting fire-induced plant mortality in shrubs and trees are largely empirical. These methods are not readily linked to duff burning, soil heating, and surface fire behavior models. In response to the need for a physics-based model of this process, a detailed model for predicting the temperature distribution through a tree stem as a function of...

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.

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...

Time-windows-based filtering method for near-surface detection of leakage from geologic carbon sequestration sites

Energy Technology Data Exchange (ETDEWEB)

Pan, L.; Lewicki, J.L.; Oldenburg, C.M.; Fischer, M.L.

2010-02-28

We use process-based modeling techniques to characterize the temporal features of natural biologically controlled surface CO{sub 2} fluxes and the relationships between the assimilation and respiration fluxes. Based on these analyses, we develop a signal-enhancing technique that combines a novel time-window splitting scheme, a simple median filtering, and an appropriate scaling method to detect potential signals of leakage of CO{sub 2} from geologic carbon sequestration sites from within datasets of net near-surface CO{sub 2} flux measurements. The technique can be directly applied to measured data and does not require subjective gap filling or data-smoothing preprocessing. Preliminary application of the new method to flux measurements from a CO{sub 2} shallow-release experiment appears promising for detecting a leakage signal relative to background variability. The leakage index of ?2 was found to span the range of biological variability for various ecosystems as determined by observing CO{sub 2} flux data at various control sites for a number of years.

Characterization of the Micro-shell Surface Using Holographic Measurements

Energy Technology Data Exchange (ETDEWEB)

Sandras, F.; Hermerel, C.; Choux, A.; Merillot, P.; Pin, G.; Jeannot, L. [CEA Valduc, Dept Rech Mat Nucl, Serv Microcibles, 21 - Is-sur-Tille (France)

2009-05-15

To characterize the shape, the quality, and the roughness of micro-shells, typically used technologies are scanning electron microscopy, scanning interferometric microscopy, or atomic force microscopy. One of the drawbacks of these techniques is that they are generally slow because of their scanning process. Digital holographic microscopy technology is an innovation that can offer ability adapted to these studies. It captures holograms instead of intensity images, as done by conventional microscopes. The holograms are then digitally interpreted (10 per second) to reconstruct a double image, one for the intensity and another one for the phase. Using a rotation axis, the bump counting for the complete micro-shell surface is possible with a very high speed. Using an image stitching software, mapping can be done in a few minutes. Wavelets such as 'Mexican hat' are used to model the bumps. Each bump can then be characterized on the map by its position, diameter, and height. (authors)

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.

Characterization of local hydrophobicity on sapphire (0001) surfaces in aqueous environment by colloidal probe atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Wada, Tomoya; Yamazaki, Kenji; Isono, Toshinari; Ogino, Toshio, E-mail: ogino-toshio-rx@ynu.ac.jp

2017-02-28

Highlights: • Local hydrophobicity of phase-separated sapphire (0001) surfaces was investigated. • These surfaces are featured by coexistence of hydrophilic and hydrophobic domains. • Each domain was characterized by colloidal probe atomic force microscopy in water. • Both domains can be distinguished by adhesive forces of the probe to the surfaces. • Characterization in aqueous environment is important in bio-applications of sapphire. - Abstract: Sapphire (0001) surfaces exhibit a phase-separation into hydrophobic and hydrophilic domains upon high-temperature annealing, which were previously distinguished by the thickness of adsorbed water layers in air using atomic force microscopy (AFM). To characterize their local surface hydrophobicity in aqueous environment, we used AFM equipped with a colloidal probe and measured the local adhesive force between each sapphire domain and a hydrophilic SiO{sub 2} probe surface, or a hydrophobic polystyrene one. Two data acquisition modes for statistical analyses were used: one is force measurements at different positions of the surface and the other repeated measurement at a fixed position. We found that adhesive force measurements using the polystyrene probe allow us to distinctly separate the hydrophilic and hydrophobic domains. The dispersion in the force measurement data at different positions of the surface is larger than that in the repeated measurements at a fixed position. It indicates that the adhesive force measurement is repeatable although their data dispersion for the measurement positions is relatively large. From these results, we can conclude that the hydrophilic and hydrophobic domains on the sapphire (0001) surfaces are distinguished by a difference in their hydration degrees.

Acid/base bifunctional carbonaceous nanomaterial with large surface area: Preparation, characterization, and adsorption properties for cationic and anionic compounds

Energy Technology Data Exchange (ETDEWEB)

Li, Kai; Ma, Chun–Fang; Ling, Yuan; Li, Meng [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Gao, Qiang, E-mail: gaoqiang@cug.edu.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Engineering Research Center of Nano-Geo Materials of Ministry of Education, China University of Geosciences, Wuhan 430074 (China); Luo, Wen–Jun, E-mail: heartnohome@yahoo.com.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China)

2015-07-15

Nanostructured carbonaceous materials are extremely important in the nano field, yet developing simple, mild, and “green” methods that can make such materials possess large surface area and rich functional groups on their surfaces still remains a considerable challenge. Herein, a one-pot and environment-friendly method, i.e., thermal treatment (180 °C; 18 h) of water mixed with glucose and chitosan (CTS), has been proposed. The resultant carbonaceous nanomaterials were characterized by field emitting scanning electron microscope, N{sub 2} adsorption/desorption, Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, and zeta-potential analysis. It was found that, in contrast to the conventional hydrothermally carbonized product from pure glucose, with low surface area (9.3 m{sup 2} g{sup −1}) and pore volume (0.016 cm{sup 3} g{sup −1}), the CTS-added carbonaceous products showed satisfactory textural parameters (surface area and pore volume up to 254 m{sup 2} g{sup −1} and 0.701 cm{sup 3} g{sup −1}, respectively). Moreover, it was also interestingly found that these CTS-added carbonaceous products possessed both acidic (–COOH) and basic (–NH{sub 2}) groups on their surfaces. Taking the advantages of large surface area and –COOH/–NH{sub 2} bifunctional surface, the carbonaceous nanomaterials exhibited excellent performance for adsorptions of cationic compound (i.e., methylene blue) at pH 10 and anionic compound (i.e., acid red 18) at pH 2, respectively. This work not only provides a simple and green route to prepare acid/base bifunctional carbonaceous nanomaterials with large surface area but also well demonstrates their potential for application in adsorption. - Highlights: • A simple and green method was proposed to prepare carbon nanomaterials. • The carbon product showed acid/base bifunctional surface with large surface area. • The carbon material could efficiently adsorb both cationic and anionic compounds.

Investigation of synthetic aperture methods in ultrasound surface imaging using elementary surface types.

Science.gov (United States)

Kerr, W; Pierce, S G; Rowe, P

2016-12-01

Synthetic aperture imaging methods have been employed widely in recent research in non-destructive testing (NDT), but uptake has been more limited in medical ultrasound imaging. Typically offering superior focussing power over more traditional phased array methods, these techniques have been employed in NDT applications to locate and characterise small defects within large samples, but have rarely been used to image surfaces. A desire to ultimately employ ultrasonic surface imaging for bone surface geometry measurement prior to surgical intervention motivates this research, and results are presented for initial laboratory trials of a surface reconstruction technique based on global thresholding of ultrasonic 3D point cloud data. In this study, representative geometry artefacts were imaged in the laboratory using two synthetic aperture techniques; the Total Focusing Method (TFM) and the Synthetic Aperture Focusing Technique (SAFT) employing full and narrow synthetic apertures, respectively. Three high precision metallic samples of known geometries (cuboid, sphere and cylinder) which featured a range of elementary surface primitives were imaged using a 5MHz, 128 element 1D phased array employing both SAFT and TFM approaches. The array was manipulated around the samples using a precision robotic positioning system, allowing for repeatable ultrasound derived 3D surface point clouds to be created. A global thresholding technique was then developed that allowed the extraction of the surface profiles, and these were compared with the known geometry samples to provide a quantitative measure of error of 3D surface reconstruction. The mean errors achieved with optimised SAFT imaging for the cuboidal, spherical and cylindrical samples were 1.3mm, 2.9mm and 2.0mm respectively, while those for TFM imaging were 3.7mm, 3.0mm and 3.1mm, respectively. These results were contrary to expectations given the higher information content associated with the TFM images. However, it was

The characterization of the antibacterial efficacy of an electrically activated silver ion-based surface system

Science.gov (United States)

Shirwaiker, Rohan A.

There have been growing concerns in the global healthcare system about the eradication of pathogens in hospitals and other health-critical environments. The problem has been aggravated by the overuse of antibiotics and antimicrobial agents leading to the emergence of antibiotic-resistant superbugs such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) which are difficult to kill. Lower immunity of sick patients coupled with the escalating concurrent problem of antibiotic-resistant pathogens has resulted in increasing incidences of hospital acquired (nosocomial) infections. There is an immediate need to control the transmission of such infections, primarily in healthcare environments, by creating touch-contact and work surfaces (e.g., door knobs, push plates, countertops) that utilize alternative antibacterial materials like the heavy metal, silver. Recent research has shown that it is silver in its ionic (Ag+ ) and not elemental form that is antibacterial. Thus, silver-based antibacterial surfaces have to release silver ions directly into the pathogenic environment (generally, an aqueous media) in order to be effective. This dissertation presents the study and analysis of a new silver-based surface system that utilizes low intensity direct electric current (LIDC) for generation of silver ions to primarily inhibit indirect contact transmission of infections. The broader objective of this research is to understand the design, and characterization of the electrically activated silver ion-based antibacterial surface system. The specific objectives of this dissertation include: (1) Developing a comprehensive system design, and identifying and studying its critical design parameters and functional mechanisms. (2) Evaluating effects of the critical design parameters on the antibacterial efficacy of the proposed surface system. (3) Developing a response surface model for the surface system performance. These objectives are

Anisotropic wetting properties on a precision-ground micro-V-grooved Si surface related to their micro-characterized variables

International Nuclear Information System (INIS)

Li, P; Xie, J; Cheng, J; Wu, K K

2014-01-01

Micro-characterized variables are proposed to precisely characterize a micro-V-grooved Si surface through the 3D measured topography rather than the designed one. In this study, level and gradient micro-grooved surfaces with depth of 25–80 µm were precisely and smoothly fabricated using a new micro-grinding process rather than laser machining and chemical etching. The objective is to investigate how these accurate micro-characterized variables systematically influence anisotropic wetting and droplet self-movement on such regular micro-structured surfaces without surface chemical modification. First, the anisotropic wetting, droplet sliding, pinning effect and droplet impact were experimentally investigated; then, theoretical anisotropic wetting models were constructed to predict and design the anisotropic wetting. The experiments show that the level micro-V-grooved surface produces the anisotropic wetting and pinning effects. It not only approximates superhydrophobicity but also produces high surface free energy. Moreover, the gradient micro-V-grooved surface with large pitch may lead to much easier droplet sliding than the level one along the micro-groove. The droplet self-movement trend increases with increasing the micro-groove gradient and micro-V-groove ratio. The micro-groove pitch and depth also influence the droplet impact. Theoretical analyses show that the wetting anisotropy and the droplet anisotropy both reach their largest value and disappear for a sharp micro-groove top when the micro-V-groove ratio is equal to 0.70 and 2.58, respectively, which may change the wetting between the composite state and the non-composite state. It is confirmed that the wetting behavior may be designed and predicted by the accurate micro-characterized variables of a regular micro-structured surface. (paper)

Anisotropic wetting properties on a precision-ground micro-V-grooved Si surface related to their micro-characterized variables

Science.gov (United States)

Li, P.; Xie, J.; Cheng, J.; Wu, K. K.

2014-07-01

Micro-characterized variables are proposed to precisely characterize a micro-V-grooved Si surface through the 3D measured topography rather than the designed one. In this study, level and gradient micro-grooved surfaces with depth of 25-80 µm were precisely and smoothly fabricated using a new micro-grinding process rather than laser machining and chemical etching. The objective is to investigate how these accurate micro-characterized variables systematically influence anisotropic wetting and droplet self-movement on such regular micro-structured surfaces without surface chemical modification. First, the anisotropic wetting, droplet sliding, pinning effect and droplet impact were experimentally investigated; then, theoretical anisotropic wetting models were constructed to predict and design the anisotropic wetting. The experiments show that the level micro-V-grooved surface produces the anisotropic wetting and pinning effects. It not only approximates superhydrophobicity but also produces high surface free energy. Moreover, the gradient micro-V-grooved surface with large pitch may lead to much easier droplet sliding than the level one along the micro-groove. The droplet self-movement trend increases with increasing the micro-groove gradient and micro-V-groove ratio. The micro-groove pitch and depth also influence the droplet impact. Theoretical analyses show that the wetting anisotropy and the droplet anisotropy both reach their largest value and disappear for a sharp micro-groove top when the micro-V-groove ratio is equal to 0.70 and 2.58, respectively, which may change the wetting between the composite state and the non-composite state. It is confirmed that the wetting behavior may be designed and predicted by the accurate micro-characterized variables of a regular micro-structured surface.

Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

Science.gov (United States)

Dwivedi, D.; Lepkova, K.; Becker, T.

2017-03-01

Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The reviewed methods include time of flight-secondary ion mass spectrometry, X-ray absorption spectroscopy methods, particle-induced X-ray emission, Rutherford backscatter spectroscopy, Auger electron spectroscopy, electron probe microanalysis, near-edge X-ray absorption fine structure spectroscopy, X-ray photoemission electron microscopy, low-energy electron diffraction, small-angle neutron scattering and neutron reflectometry, and conversion electron Moessbauer spectrometry. Advantages and limitations of the analytical methods in thin-film surface investigations are discussed. Technical parameters of nominated analytical methods are provided to assist in the selection of suitable methods for analysis of metallic substrates deposited with surface films. The challenges associated with the applications of the emerging analytical methods in corrosion science are also addressed.

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.

An Optimization Method for Virtual Globe Ocean Surface Dynamic Visualization

Directory of Open Access Journals (Sweden)

HUANG Wumeng

2016-12-01

Full Text Available The existing visualization method in the virtual globe mainly uses the projection grid to organize the ocean grid. This special grid organization has the defects in reflecting the difference characteristics of different ocean areas. The method of global ocean visualization based on global discrete grid can make up the defect of the projection grid method by matching with the discrete space of the virtual globe, so it is more suitable for the virtual ocean surface simulation application.But the available global discrete grids method has many problems which limiting its application such as the low efficiency of rendering and loading, the need of repairing grid crevices. To this point, we propose an optimization for the global discrete grids method. At first, a GPU-oriented multi-scale grid model of ocean surface which develops on the foundation of global discrete grids was designed to organize and manage the ocean surface grids. Then, in order to achieve the wind-drive wave dynamic rendering, this paper proposes a dynamic wave rendering method based on the multi-scale ocean surface grid model to support real-time wind field updating. At the same time, considering the effect of repairing grid crevices on the system efficiency, this paper presents an efficient method for repairing ocean surface grid crevices based on the characteristics of ocean grid and GPU technology. At last, the feasibility and validity of the method are verified by the comparison experiment. The experimental results show that the proposed method is efficient, stable and fast, and can compensate for the lack of function of the existing methods, so the application range is more extensive.

Synthesis, X-ray diffraction method, spectroscopic characterization (FT-IR, 1H and 13C NMR), antimicrobial activity, Hirshfeld surface analysis and DFT computations of novel sulfonamide derivatives

Science.gov (United States)

Demircioğlu, Zeynep; Özdemir, Fethi Ahmet; Dayan, Osman; Şerbetçi, Zafer; Özdemir, Namık

2018-06-01

Synthesized compounds of N-(2-aminophenyl)benzenesulfonamide 1 and (Z)-N-(2-((2-nitrobenzylidene)amino)phenyl)benzenesulfonamide 2 were characterized by antimicrobial activity, FT-IR, 1H and 13C NMR. Two new Schiff base ligands containing aromatic sulfonamide fragment of (Z)-N-(2-((3-nitrobenzylidene)amino)phenyl)benzenesulfonamide 3 and (Z)-N-(2-((4-nitrobenzylidene)amino)phenyl)benzenesulfonamide 4 were synthesized and investigated by spectroscopic techniques including 1H and 13C NMR, FT-IR, single crystal X-ray diffraction, Hirshfeld surface, theoretical method analyses and by antimicrobial activity. The molecular geometry obtained from the X-ray structure determination was optimized Density Functional Theory (DFT/B3LYP) method with the 6-311++G(d,p) basis set in ground state. From the optimized geometry of the molecules of 3 and 4, the geometric parameters, vibrational wavenumbers and chemical shifts were computed. The optimized geometry results, which were well represented the X-ray data, were shown that the chosen of DFT/B3LYP 6-311G++(d,p) was a successful choice. After a successful optimization, frontier molecular orbitals, chemical activity, non-linear optical properties (NLO), molecular electrostatic mep (MEP), Mulliken population method, natural population analysis (NPA) and natural bond orbital analysis (NBO), which cannot be obtained experimentally, were calculated and investigated.

Characterizing water surface elevation under different flow conditions for the upcoming SWOT mission

Science.gov (United States)

Domeneghetti, A.; Schumann, G. J.-P.; Frasson, R. P. M.; Wei, R.; Pavelsky, T. M.; Castellarin, A.; Brath, A.; Durand, M. T.

2018-06-01

The Surface Water and Ocean Topography satellite mission (SWOT), scheduled for launch in 2021, will deliver two-dimensional observations of water surface heights for lakes, rivers wider than 100 m and oceans. Even though the scientific literature has highlighted several fields of application for the expected products, detailed simulations of the SWOT radar performance for a realistic river scenario have not been presented in the literature. Understanding the error of the most fundamental "raw" SWOT hydrology product is important in order to have a greater awareness about strengths and limits of the forthcoming satellite observations. This study focuses on a reach (∼140 km in length) of the middle-lower portion of the Po River, in Northern Italy, and, to date, represents one of the few real-case analyses of the spatial patterns in water surface elevation accuracy expected from SWOT. The river stretch is characterized by a main channel varying from 100 to 500 m in width and a large floodplain (up to 5 km) delimited by a system of major embankments. The simulation of the water surface along the Po River for different flow conditions (high, low and mean annual flows) is performed with inputs from a quasi-2D model implemented using detailed topographic and bathymetric information (LiDAR, 2 m resolution). By employing a simulator that mimics many SWOT satellite sensor characteristics and generates proxies of the remotely sensed hydrometric data, this study characterizes the spatial observations potentially provided by SWOT. We evaluate SWOT performance under different hydraulic conditions and assess possible effects of river embankments, river width, river topography and distance from the satellite ground track. Despite analyzing errors from the raw radar pixel cloud, which receives minimal processing, the present study highlights the promising potential of this Ka-band interferometer for measuring water surface elevations, with mean elevation errors of 0.1 cm and 21

Characterization of mixed waste for sorting and inspection using non-intrusive methods

International Nuclear Information System (INIS)

Roberson, G.P.; Ryon, R.W.; Bull, N.L.

1994-12-01

Characterization of mixed wastes (that is, radioactive and otherwise hazardous) requires that all hazardous, non-conforming, and radioactive materials be identified, localized, and quantified. With such information, decisions can be made regarding whether the item is treatable or has been adequately treated. Much of the required information can be gained without taking representative samples and analyzing them in a chemistry laboratory. Non-intrusive methods can be used to provide this information on-line at the waste treatment facility. Ideally, the characterization would be done robotically, and either automatically or semi-automatically in order to improve efficiency and safety. For the FY94 Mixed Waste Operations (MWO) project, a treatable waste item is defined as a homogeneous metal object that has external radioactive or heavy metal hazardous contamination. Surface treatment of some kind would therefore be the treatment method to be investigated. The authors developed sorting and inspection requirements, and assessed viable non-intrusive techniques to meet these requirements. They selected radiography, computed tomography and X-ray fluorescence. They have characterized selected mock waste items, and determined minimum detectable amounts of materials. They have demonstrated the efficiency possible by integrating radiographic with tomographic data. Here, they developed a technique to only use radiographic data where the material is homogeneous (fast), and then switching to tomography in those areas where heterogeneity is detected (slower). They also developed a tomographic technique to quantify the volume of each component of a mixed material. This is useful for such things as determining ash content. Lastly, they have developed a document in MOSAIC, an Internet multi-media browser. This document is used to demonstrate the ability to share data and information world-wide

Biomimetic hydrophobic surface fabricated by chemical etching method from hierarchically structured magnesium alloy substrate

Energy Technology Data Exchange (ETDEWEB)

Liu, Yan; Yin, Xiaoming; Zhang, Jijia [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); Wang, Yaming [Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin 150001 (China); Han, Zhiwu, E-mail: zwhan@jlu.edu.cn [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); Ren, Luquan [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China)

2013-09-01

As one of the lightest metal materials, magnesium alloy plays an important role in industry such as automobile, airplane and electronic product. However, magnesium alloy is hindered due to its high chemical activity and easily corroded. Here, inspired by typical plant surfaces such as lotus leaves and petals of red rose with super-hydrophobic character, the new hydrophobic surface is fabricated on magnesium alloy to improve anti-corrosion by two-step methodology. The procedure is that the samples are processed by laser first and then immersed and etched in the aqueous AgNO{sub 3} solution concentrations of 0.1 mol/L, 0.3 mol/L and 0.5 mol/L for different times of 15 s, 40 s and 60 s, respectively, finally modified by DTS (CH{sub 3}(CH{sub 2}){sub 11}Si(OCH{sub 3}){sub 3}). The microstructure, chemical composition, wettability and anti-corrosion are characterized by means of SEM, XPS, water contact angle measurement and electrochemical method. The hydrophobic surfaces with microscale crater-like and nanoscale flower-like binary structure are obtained. The low-energy material is contained in surface after DTS treatment. The contact angles could reach up to 138.4 ± 2°, which hydrophobic property is both related to the micro–nano binary structure and chemical composition. The results of electrochemical measurements show that anti-corrosion property of magnesium alloy is improved. Furthermore, our research is expected to create some ideas from natural enlightenment to improve anti-corrosion property of magnesium alloy while this method can be easily extended to other metal materials.

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)