Selection of the reference concept for the surface examination stations in the fuels and materials examination facility

International Nuclear Information System (INIS)

Frandsen, G.B.; Nash, C.R.

1978-01-01

The prototype surface examination station for the Fuels and Materials Examination Facility (FMEF) will use closed circuit television (CCTV) for routine modes of operation along with a nuclear periscope for special examination needs. The CCTV and the nuclear periscope were evaluated against prescribed station requirements and compared in a side-by-side demonstration. A quantitative evaluation of their outputs showed that both systems were capable of meeting surface anomaly detection requirements. The CCTV system was superior in its ability to collect, suppress and present data into a more useful form for the experimenters

Efficient and Anisotropic Fog Harvesting on a Hybrid and Directional Surface

KAUST Repository

Wu, Jinbo

2016-12-05

A straight throughout superhydrophilic track that contains high contrast and directional wettability on a superhydrophobic surface is designed. Despite droplets that tend to slide more easily along a direction parallel to the track, it is found that such hybrid strip-pattern surfaces have higher fog harvesting efficiency along a direction perpendicular to the tracks due to the larger accumulation area for droplet removal.

Direct instrumental identification of catalytically active surface sites

Science.gov (United States)

Pfisterer, Jonas H. K.; Liang, Yunchang; Schneider, Oliver; Bandarenka, Aliaksandr S.

2017-09-01

The activity of heterogeneous catalysts—which are involved in some 80 per cent of processes in the chemical and energy industries—is determined by the electronic structure of specific surface sites that offer optimal binding of reaction intermediates. Directly identifying and monitoring these sites during a reaction should therefore provide insight that might aid the targeted development of heterogeneous catalysts and electrocatalysts (those that participate in electrochemical reactions) for practical applications. The invention of the scanning tunnelling microscope (STM) and the electrochemical STM promised to deliver such imaging capabilities, and both have indeed contributed greatly to our atomistic understanding of heterogeneous catalysis. But although the STM has been used to probe and initiate surface reactions, and has even enabled local measurements of reactivity in some systems, it is not generally thought to be suited to the direct identification of catalytically active surface sites under reaction conditions. Here we demonstrate, however, that common STMs can readily map the catalytic activity of surfaces with high spatial resolution: we show that by monitoring relative changes in the tunnelling current noise, active sites can be distinguished in an almost quantitative fashion according to their ability to catalyse the hydrogen-evolution reaction or the oxygen-reduction reaction. These data allow us to evaluate directly the importance and relative contribution to overall catalyst activity of different defects and sites at the boundaries between two materials. With its ability to deliver such information and its ready applicability to different systems, we anticipate that our method will aid the rational design of heterogeneous catalysts.

Surface return direction-of-arrival analysis for radar ice sounding surface clutter suppression

DEFF Research Database (Denmark)

Nielsen, Ulrik; Dall, Jørgen

2015-01-01

Airborne radar ice sounding is challenged by surface clutter masking the depth signal of interest. Surface clutter may even be prohibitive for potential space-based ice sounding radars. To some extent the radar antenna suppresses the surface clutter, and a multi-phase-center antenna in combination...... with coherent signal processing techniques can improve the suppression, in particular if the direction of arrival (DOA) of the clutter signal is estimated accurately. This paper deals with data-driven DOA estimation. By using P-band data from the ice shelf in Antarctica it is demonstrated that a varying...

Reduction of radiation exposure for the examiner in angiography using a direct dosimeter

International Nuclear Information System (INIS)

Kamusella, Peter; Wissgott, C.; Scheer, F.; Andresen, R.; Wiggermann, P.

2013-01-01

Purpose: To evaluate whether a reduction in radiation exposure can be achieved using a direct dosimeter with an acoustic warning signal (model EDD-30, Unfors Instruments, Billdal, Sweden). Materials and Methods: A total of 183 diagnostic and interventional angiographies of the pelvis and lower limbs using a direct dosimeter were analyzed. The vascular interventions were performed either by an experienced examiner (> 5000 interventions), an intermediate examiner (> 1000 interventions) or by a beginner (< 200 interventions). The measuring sensor of the direct dosimeter was attached to the back of the left hand, below the sterile glove, and was worn throughout the examination. If the limit values set on the dosimeter were exceeded, an acoustic signal sounded. At the end of the examination, the mean dose and the mean dose rate could be read off directly. Results: Exposure is clearly dependent on the experience of the examiner. The highest mean dose rate was found for the beginner, followed by the intermediate examiner. The lowest dose rate was shown by the experienced examiner, even though he mostly performed complex interventions. Over the course of 3 months, an improvement in the average dose rate can be shown in the third month for the intermediate examiner. Conclusion: The use of a direct dosimeter with an acoustic warning signal is a practicable tool for sensitizing interventional radiologists to unavoidable radiation exposure, with the aim of reducing the dose. 'Real-time' dosimetry represents a sensible extension of indirect protection of the radiation-exposed examiner in angiography. (orig.)

Macroscopic and radiographic examination of proximal root surface caries

International Nuclear Information System (INIS)

Nordenram, G.; Bergvist, A.; Johnson, G.; Henriksen, C.O.; Anneroth, G.

1988-01-01

The purpose of the study was to compare macroscopic and radiographic examination of proximal root surface caries of extracted teeth from patients aged 65-95 years. Although the study conditions for macroscopic and radiographic diagnosis favored more sensitive evaluations than routine clinical conditions, there was a 24% disagreement in diagnosis. This finding indicates that under routine clinical conditions it is difficult to register with certainty all superficial root carious lesions. Even in the absence of clinically detectable root surface caries, preventive measures should be considered for elderly people with exposed root surfaces

Modeling directional effects in land surface temperature derived from geostationary satellite data

DEFF Research Database (Denmark)

Rasmussen, Mads Olander

This PhD-thesis investigates the directional effects in land surface temperature (LST) estimates from the SEVIRI sensor onboard the Meteosat Second Generation (MSG) satellites. The directional effects are caused by the land surface structure (i.e. tree size and shape) interacting with the changing...... sun-target-sensor geometry. The directional effects occur because the different surface components, e.g. tree canopies and bare soil surfaces, will in many cases have significantly different temperatures. Depending on the viewing angle, different fractions of each of the components will be viewed...... by the sensor. This is further complicated by temperature differences between the sunlit and shaded parts of each of the components, controlled by the exposure of the components to direct sunlight. As the SEVIRI sensor is onboard a geostationary platform, the viewing geometry is fixed (for each pixel), while...

Probing Anisotropic Surface Properties of Molybdenite by Direct Force Measurements.

Science.gov (United States)

Lu, Zhenzhen; Liu, Qingxia; Xu, Zhenghe; Zeng, Hongbo

2015-10-27

Probing anisotropic surface properties of layer-type mineral is fundamentally important in understanding its surface charge and wettability for a variety of applications. In this study, the surface properties of the face and the edge surfaces of natural molybdenite (MoS2) were investigated by direct surface force measurements using atomic force microscope (AFM). The interaction forces between the AFM tip (Si3N4) and face or edge surface of molybdenite were measured in 10 mM NaCl solutions at various pHs. The force profiles were well-fitted with classical DLVO (Derjaguin-Landau-Verwey-Overbeek) theory to determine the surface potentials of the face and the edge surfaces of molybdenite. The surface potentials of both the face and edge surfaces become more negative with increasing pH. At neutral and alkaline conditions, the edge surface exhibits more negative surface potential than the face surface, which is possibly due to molybdate and hydromolybdate ions on the edge surface. The point of zero charge (PZC) of the edge surface was determined around pH 3 while PZC of the face surface was not observed in the range of pH 3-11. The interaction forces between octadecyltrichlorosilane-treated AFM tip (OTS-tip) and face or edge surface of molybdenite were also measured at various pHs to study the wettability of molybdenite surfaces. An attractive force between the OTS-tip and the face surface was detected. The force profiles were well-fitted by considering DLVO forces and additional hydrophobic force. Our results suggest the hydrophobic feature of the face surface of molybdenite. In contrast, no attractive force between the OTS-tip and the edge surface was detected. This is the first study in directly measuring surface charge and wettability of the pristine face and edge surfaces of molybdenite through surface force measurements.

Direct evaluation of transient surface temperatures and heat fluxes

International Nuclear Information System (INIS)

Axford, R.A.

1975-08-01

Evaluations of transient surface temperatures resulting from the absorption of radiation are required in laser fusion reactor systems studies. A general method for the direct evaluation of transient surface temperatures and heat fluxes on the boundaries of bounded media is developed by constructing fundamental solutions of the scalar Helmholtz equation and performing certain elementary integrations

Direct methods for surface X-ray diffraction

International Nuclear Information System (INIS)

Saldin, D. K.; Harder, R.; Shneerson, V. L.; Vogler, H.; Moritz, W.

2000-01-01

We develop of a direct method for surface X-ray diffraction that exploits the holographic feature of a known reference wave from the substrate. A Bayesian analysis of the optimal inference to be made from an incomplete data set suggests a maximum entropy algorithm that balances agreement with the data and other statistical considerations

Extending the Direct Behavior Rating: An Examination of Schoolwide Behavior Ratings and Academic Engagement

Science.gov (United States)

Bruhn, Allison; Barron, Sheila; Fernando, Josephine; Balint-Langel, Kinga

2018-01-01

Direct behavior ratings have been identified as a practical and feasible alternative to direct observation of behavior for monitoring behavioral progress. Despite the evidence of usability, there have been calls for further examination of direct behavior ratings using different behaviors and scales. To this end, we examined the ratings of…

Efficient and Anisotropic Fog Harvesting on a Hybrid and Directional Surface

KAUST Repository

Wu, Jinbo; Zhang, Lianbin; Wang, Yuchao; Wang, Peng

2016-01-01

A straight throughout superhydrophilic track that contains high contrast and directional wettability on a superhydrophobic surface is designed. Despite droplets that tend to slide more easily along a direction parallel to the track, it is found

Direct surface magnetometry with photoemission magnetic x-ray dichroism

Energy Technology Data Exchange (ETDEWEB)

Tobin, J.G.; Goodman, K.W. [Lawrence Berkeley National Lab., CA (United States); Schumann, F.O. [Pennsylvania State Univ., University Park, PA (United States)] [and others

1997-04-01

Element specific surface magnetometry remains a central goal of synchrotron radiation based studies of nanomagnetic structures. One appealing possibility is the combination of x-ray absorption dichroism measurements and the theoretical framework provided by the {open_quotes}sum rules.{close_quotes} Unfortunately, sum rule analysis are hampered by several limitations including delocalization of the final state, multi-electronic phenomena and the presence of surface dipoles. An alternative experiment, Magnetic X-Ray Dichroism in Photoelectron Spectroscopy, holds out promise based upon its elemental specificity, surface sensitivity and high resolution. Computational simulations by Tamura et al. demonstrated the relationship between exchange and spin orbit splittings and experimental data of linear and circular dichroisms. Now the authors have developed an analytical framework which allows for the direct extraction of core level exchange splittings from circular and linear dichroic photoemission data. By extending a model initially proposed by Venus, it is possible to show a linear relation between normalized dichroism peaks in the experimental data and the underlying exchange splitting. Since it is reasonable to expect that exchange splittings and magnetic moments track together, this measurement thus becomes a powerful new tool for direct surface magnetometry, without recourse to time consuming and difficult spectral simulations. The theoretical derivation will be supported by high resolution linear and circular dichroism data collected at the Spectromicroscopy Facility of the Advanced Light Source.

pH-sensitive diamond field-effect transistors (FETs) with directly aminated channel surface

International Nuclear Information System (INIS)

Song, Kwang-Soup; Nakamura, Yusuke; Sasaki, Yuichi; Degawa, Munenori; Yang, Jung-Hoon; Kawarada, Hiroshi

2006-01-01

We have introduced pH sensors fabricated on diamond thin films through modification of the surface-terminated atom. We directly modified the diamond surface from hydrogen to amine or oxygen with ultraviolet (UV) irradiation under ammonia gas. The quantified amine site based on the spectra obtained by X-ray photoelectron spectroscopy (XPS) is 26% (2.6 x 10 14 cm -2 ) with UV irradiation for 8 h and its coverage is dependent on the UV irradiation time. This directly aminated diamond surface is stable with long-term exposure in air and electrolyte solution. We fabricated diamond solution-gate field-effect transistors (SGFETs) without insulating layers on the channel surface. These diamond SGFETs with amine modified by direct amination are sensitive to pH (45 mV/pH) over a wide range from pH 2 to 12 and their sensitivity is dependent on the density of binding sites corresponding to UV irradiation time on the channel surface

Direct modification of silicon surface by nanosecond laser interference lithography

Energy Technology Data Exchange (ETDEWEB)

Wang, Dapeng [JR3CN and CNM (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN and IRAC (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Wang, Zuobin, E-mail: wangz@cust.edu.cn [JR3CN and CNM (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN and IRAC (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Zhang, Ziang [JR3CN and CNM (Changchun University of Science and Technology), Changchun 130022 (China); Yue, Yong [JR3CN and CNM (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN and IRAC (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Li, Dayou [JR3CN and IRAC (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Maple, Carsten [JR3CN and CNM (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN and IRAC (University of Bedfordshire), Luton LU1 3JU (United Kingdom)

2013-10-01

Periodic and quasi-periodic structures on silicon surface have numerous significant applications in photoelectronics and surface engineering. A number of technologies have been developed to fabricate the structures in various research fields. In this work, we take the strategy of direct nanosecond laser interference lithography technology, and focus on the silicon material to create different well-defined surface structures based on theoretical analysis of the formation of laser interference patterns. Two, three and four-beam laser interference systems were set up to fabricate the grating, regular triangle and square structures on silicon surfaces, respectively. From the AFM micrographs, the critical features of structures have a dependence on laser fluences. For a relative low laser fluence, grating and dot structures formed with bumps due to the Marangoni Effect. With the increase of laser fluences, melt and evaporation behaviors can be responsible for the laser modification. By properly selecting the process parameters, well-defined grating and dot structures can been achieved. It can be demonstrated that direct laser interference lithography is a facile and efficient technology with the advantage of a single process procedure over macroscale areas for the fabrication of micro and nano structures.

Directed transport by surface chemical potential gradients for enhancing analyte collection in nanoscale sensors.

Science.gov (United States)

Sitt, Amit; Hess, Henry

2015-05-13

Nanoscale detectors hold great promise for single molecule detection and the analysis of small volumes of dilute samples. However, the probability of an analyte reaching the nanosensor in a dilute solution is extremely low due to the sensor's small size. Here, we examine the use of a chemical potential gradient along a surface to accelerate analyte capture by nanoscale sensors. Utilizing a simple model for transport induced by surface binding energy gradients, we study the effect of the gradient on the efficiency of collecting nanoparticles and single and double stranded DNA. The results indicate that chemical potential gradients along a surface can lead to an acceleration of analyte capture by several orders of magnitude compared to direct collection from the solution. The improvement in collection is limited to a relatively narrow window of gradient slopes, and its extent strongly depends on the size of the gradient patch. Our model allows the optimization of gradient layouts and sheds light on the fundamental characteristics of chemical potential gradient induced transport.

Direct Monte Carlo dose calculation using polygon-surface computational human model

International Nuclear Information System (INIS)

Jeong, Jong Hwi; Kim, Chan Hyeong; Yeom, Yeon Su; Cho, Sungkoo; Chung, Min Suk; Cho, Kun-Woo

2011-01-01

In the present study, a voxel-type computational human model was converted to a polygon-surface model, after which it was imported directly to the Geant4 code without using a voxelization process, that is, without converting back to a voxel model. The original voxel model was also imported to the Geant4 code, in order to compare the calculated dose values and the computational speed. The average polygon size of the polygon-surface model was ∼0.5 cm 2 , whereas the voxel resolution of the voxel model was 1.981 × 1.981 × 2.0854 mm 3 . The results showed a good agreement between the calculated dose values of the two models. The polygon-surface model was, however, slower than the voxel model by a factor of 6–9 for the photon energies and irradiation geometries considered in the present study, which nonetheless is considered acceptable, considering that direct use of the polygon-surface model does not require a separate voxelization process. (author)

Ultrasonic examination of defects close to the outer surface

International Nuclear Information System (INIS)

Benoist, P.; Serre, M.; Champigny, F.

1986-11-01

During the examination of a pressurized water reactor vessel with an in Service Inspection Machine (MIS), various welds are scanned with immersion ultrasonic focused transducers from the inside of the vessel. Defects close to the outer surface are sometimes detected, and sizing with the successive 6 dB drop method leads to oversize some indications; this is caused by various reflections on the outer wall; the corner echo is of particular importance here. CEA and EDF have started an experimental program in order to study the response of volumetric and planar defects located near the outer surface. We present here the first results obtained with artificial defects. 2 refs

Direct measurement of sub-Debye-length attraction between oppositely charged surfaces.

Science.gov (United States)

Kampf, Nir; Ben-Yaakov, Dan; Andelman, David; Safran, S A; Klein, Jacob

2009-09-11

Using a surface force balance with fast video analysis, we have measured directly the attractive forces between oppositely charged solid surfaces (charge densities sigma(+), sigma(-)) across water over the entire range of interaction, in particular, at surface separations D below the Debye screening length lambda(S). At very low salt concentration we find a long-ranged attraction between the surfaces (onset ca. 100 nm), whose variation at Dsurface charge asymmetry (sigma(+) not equal to |sigma(-)|).

Defect detection and classification of machined surfaces under multiple illuminant directions

Science.gov (United States)

Liao, Yi; Weng, Xin; Swonger, C. W.; Ni, Jun

2010-08-01

Continuous improvement of product quality is crucial to the successful and competitive automotive manufacturing industry in the 21st century. The presence of surface porosity located on flat machined surfaces such as cylinder heads/blocks and transmission cases may allow leaks of coolant, oil, or combustion gas between critical mating surfaces, thus causing damage to the engine or transmission. Therefore 100% inline inspection plays an important role for improving product quality. Although the techniques of image processing and machine vision have been applied to machined surface inspection and well improved in the past 20 years, in today's automotive industry, surface porosity inspection is still done by skilled humans, which is costly, tedious, time consuming and not capable of reliably detecting small defects. In our study, an automated defect detection and classification system for flat machined surfaces has been designed and constructed. In this paper, the importance of the illuminant direction in a machine vision system was first emphasized and then the surface defect inspection system under multiple directional illuminations was designed and constructed. After that, image processing algorithms were developed to realize 5 types of 2D or 3D surface defects (pore, 2D blemish, residue dirt, scratch, and gouge) detection and classification. The steps of image processing include: (1) image acquisition and contrast enhancement (2) defect segmentation and feature extraction (3) defect classification. An artificial machined surface and an actual automotive part: cylinder head surface were tested and, as a result, microscopic surface defects can be accurately detected and assigned to a surface defect class. The cycle time of this system can be sufficiently fast that implementation of 100% inline inspection is feasible. The field of view of this system is 150mm×225mm and the surfaces larger than the field of view can be stitched together in software.

Forensic Examination Using a Nondestructive Evaluation Method for Surface Metrology

Science.gov (United States)

Eisenmann, David J.; Chumbley, L. Scott

2009-03-01

The objective of this paper is to describe the use of a new technique of optical profilometry in a nondestructive, non-contact fashion for the comparison of two metallic surfaces, one hard and one soft. When brought in contact with one another, the harder material (i.e. the tool) will impress its surface roughness onto the softer. It is understood that the resulting set of impressions left from a tool tip act in a manner similar to a photographic negative, in that it leaves a reverse, or negative impression on the surface of a plate. If properly inverted and reversed, measurements from the softer material should be identical to the harder indenting object with regard to surface texture and roughness. This assumption is inherent in the area of forensics, where bullets, cartridge cases, and toolmarked surfaces from crime scenes are compared to similar marks made under controlled conditions in the forensic laboratory. This paper will examine the methodology used to compare two surfaces for similarities and dissimilarities, and comment on the applicability of this technique to other studies.

Examining the Early Evidence for Self-Directed Marriage and Relationship Education: A Meta-Analytic Study

Science.gov (United States)

McAllister, Shelece; Duncan, Stephen F.; Hawkins, Alan J.

2012-01-01

This meta-analysis examines the efficacy of self-directed marriage and relationship education (MRE) programs on relationship quality and communication skills. Programs combining traditional face-to-face learning with self-directed elements are also examined, and traditional programs' effectiveness is included as a comparison point. Sixteen studies…

Fabrication of multi-functional silicon surface by direct laser writing

Science.gov (United States)

Verma, Ashwani Kumar; Soni, R. K.

2018-05-01

We present a simple, quick and one-step methodology based on nano-second laser direct writing for the fabrication of micro-nanostructures on silicon surface. The fabricated surfaces suppress the optical reflection by multiple reflection due to light trapping effect to a much lower value than polished silicon surface. These textured surfaces offer high enhancement ability after gold nanoparticle deposition and then explored for Surface Enhanced Raman Scattering (SERS) for specific molecular detection. The effect of laser scanning line interval on optical reflection and SERS signal enhancement ability was also investigated. Our results indicate that low optical reflection substrates exhibit uniform SERS enhancement with enhancement factor of the order of 106. Furthermore, this methodology provide an alternative approach for cost-effective large area fabrication with good control over feature size.

Remote sensing of land surface temperature: The directional viewing effect

International Nuclear Information System (INIS)

Smith, J.A.; Schmugge, T.J.; Ballard, J.R. Jr.

1997-01-01

Land Surface Temperature (LST) is an important parameter in understanding global environmental change because it controls many of the underlying processes in the energy budget at the surface and heat and water transport between the surface and the atmosphere. The measurement of LST at a variety of spatial and temporal scales and extension to global coverage requires remote sensing means to achieve these goals. Land surface temperature and emissivity products are currently being derived from satellite and aircraft remote sensing data using a variety of techniques to correct for atmospheric effects. Implicit in the commonly employed approaches is the assumption of isotropy in directional thermal infrared exitance. The theoretical analyses indicate angular variations in apparent infrared temperature will typically yield land surface temperature errors ranging from 1 to 4 C unless corrective measures are applied

Directional mass transport in an atmospheric pressure surface barrier discharge.

Science.gov (United States)

Dickenson, A; Morabit, Y; Hasan, M I; Walsh, J L

2017-10-25

In an atmospheric pressure surface barrier discharge the inherent physical separation between the plasma generation region and downstream point of application reduces the flux of reactive chemical species reaching the sample, potentially limiting application efficacy. This contribution explores the impact of manipulating the phase angle of the applied voltage to exert a level of control over the electrohydrodynamic forces generated by the plasma. As these forces produce a convective flow which is the primary mechanism of species transport, the technique facilitates the targeted delivery of reactive species to a downstream point without compromising the underpinning species generation mechanisms. Particle Imaging Velocimetry measurements are used to demonstrate that a phase shift between sinusoidal voltages applied to adjacent electrodes in a surface barrier discharge results in a significant deviation in the direction of the plasma induced gas flow. Using a two-dimensional numerical air plasma model, it is shown that the phase shift impacts the spatial distribution of the deposited charge on the dielectric surface between the adjacent electrodes. The modified surface charge distribution reduces the propagation length of the discharge ignited on the lagging electrode, causing an imbalance in the generated forces and consequently a variation in the direction of the resulting gas flow.

Determining eyeball surface area directly exposed to the effects of external factors.

Science.gov (United States)

Juliszewski, Tadeusz; Kadłuczka, Filip; Kiełbasa, Paweł

2016-01-01

This article discusses determining the surface area of eyeballs of men and women exposed to the direct effects of external factors in the working environment. For one eye, the mean surface is 172-182 mm(2). The determined surface area can be used in formulas for calculating the exposure of eyeballs to harmful chemical substances in workplace air.

Analysis on the entrance surface dose and contrast medium dose at computed tomography and angiography in cardiovascular examination

Energy Technology Data Exchange (ETDEWEB)

Seo, Young Hyun [Dept. of Cardiovascular Center, Yeocheon Jeonnam Hospital, Yeosu (Korea, Republic of); Han, Jae Bok; Choi, Nam Gil; Song, Jong Nam [Dept. of Radiological Science, Dongshin University, Naju (Korea, Republic of)

2016-12-15

This study aimed to identify dose reduction measures by retrospectively analyzing the entrance surface dose at computed tomography and angiography in cardiovascular examination and to contribute the patients with renal impairmend and a high probability of side effects to determine the inspection's direction by measuring the contrast usages actually to active actions for the dose by actually measuring the contrast medium dose. The CTDIvol value and air kerma value, which are the entrance surface doses of the two examinations, and the contrast medium dose depending on the number of slides were compared and analyzed. This study was conducted in 21 subjects (11 males; 10 females) who underwent Cardiac Computed Tomographic Angiography (CCTA) and Coronary Angiography (CAG) in this hospital during the period from May 2014 to May 2016. The subject's age was 48-85 years old (mean 65±10 years old), and the weight was 37.6~83.3 kg (mean 63±6 kg). Dose reduction could be expected in the cardiovascular examination using CCTA rather than in the examination using CAG. In terms of contrast medium dose, CAG used a smaller dose than CCTA. In particular, as the number of slides increases at CAG, the contrast medium dose increases. Therefore, in order to reduce the contrast medium dose, the number of slides suitable for the scan range must be selected.

Direct measurement of surface-state conductance by microscopic four-point probe method

DEFF Research Database (Denmark)

Hasegawa, S.; Shiraki, I.; Tanikawa, T.

2002-01-01

For in situ measurements of local electrical conductivity of well defined crystal surfaces in ultrahigh vacuum, we have developed microscopic four-point probes with a probe spacing of several micrometres, installed in a scanning-electron - microscope/electron-diffraction chamber. The probe...... is precisely positioned on targeted areas of the sample surface by using piezoactuators. This apparatus enables conductivity measurement with extremely high surface sensitivity, resulting in direct access to surface-state conductivity of the surface superstructures, and clarifying the influence of atomic steps...

Studies on surface modification of poly(tetrafluoroethylene) film by remote and direct Ar plasma

International Nuclear Information System (INIS)

Wang Chen; Chen Jierong; Li Ru

2008-01-01

Poly(tetrafluoroethylene) (PTFE) surfaces are modified with remote and direct Ar plasma, and the effects of the modification on the hydrophilicity of PTFE are investigated. The surface microstructures and compositions of the PTFE film were characterized with the goniometer, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Results show that the remote and direct plasma treatments modify the PTFE surface in morphology and composition, and both modifications cause surface oxidation of PTFE films, in the forming of some polar functional groups enhancing polymer wettability. When the remote and direct Ar plasma treats PTFE film, the contact angles decrease from the untreated 108-58 o and 65.2 o , respectively. The effect of the remote Ar plasma is more noticeable. The role of all kinds of active species, e.g. electrons, ions and free radicals involved in plasma surface modification is further evaluated. This shows that remote Ar plasma can restrain the ion and electron etching reaction and enhance radical reaction

Near-surface structural examination of human tooth enamel subject to in vitro demineralization and remineralization

Science.gov (United States)

Gaines, Carmen Veronica

The early stages of chemical tooth decay are governed by dynamic processes of demineralization and remineralization of dental enamel that initiates along the surface of the tooth. Conventional diagnostic techniques lack the spatial resolution required to analyze near-surface structural changes in enamel at the submicron level. In this study, slabs of highly-polished, decay-free human enamel were subjected to 0.12M EDTA and buffered lactic acid demineralizing agents and MI Paste(TM) and calcifying (0.1 ppm F) remineralizing treatments in vitro. Grazing incidence x-ray diffraction (GIXD), a technique typically used for thin film analysis, provided depth profiles of crystallinity changes in surface enamel with a resolution better than 100 nm. In conjunction with nanoindentation, a technique gaining acceptance as a means of examining the mechanical properties of sound enamel, these results were corroborated with well-established microscopy and Raman techniques to assess the nanohardness, morphologies and chemical nature of treated enamel. Interestingly, the average crystallite size of surface enamel along its c-axis dimension increased by nearly 40% after a 60 min EDTA treatment as detected by GIXD. This result was in direct contrast to the obvious surface degradation observed by microscopic and confocal Raman imaging. A decrease in nanohardness from 4.86 +/- 0.44 GPa to 0.28 +/- 0.10 GPa was observed. Collective results suggest that mineral dissolution characteristics evident on the micron scale may not be fully translated to the nanoscale in assessing the integrity of chemically-modified tooth enamel. While an intuitive decrease in enamel crystallinity was observed with buffered lactic acid-treated samples, demineralization was too slow to adequately quantify the enamel property changes seen. MI Paste(TM) treatment of EDTA-demineralized enamel showed preferential growth along the a-axis direction. Calcifying solution treatments of both demineralized sample types

Should cavitation in proximal surfaces be reported in cone beam computed tomography examination

DEFF Research Database (Denmark)

Sansare, K.; Singh, D.; Sontakke, S.

2014-01-01

proximal surfaces without restorations in permanent teeth were examined. Patients suspected to have carious lesions after a visual clinical and a bitewing examination participated in a CBCT examination (Kodak 9000 3D, 5 × 3.7 cm field of view, voxel size 0.07 mm). Ethical approval and informed consent were...

Direct surface PEGylation of nanodiamond via RAFT polymerization

International Nuclear Information System (INIS)

Shi, Yingge; Liu, Meiying; Wang, Ke; Huang, Hongye; Wan, Qing; Tao, Lei; Fu, Lihua; Zhang, Xiaoyong; Wei, Yen

2015-01-01

Graphical abstract: In this paper, we describe an efficient, practical and novel method to modify ND via direct immobilization of chain transfer agent for RAFT polymerization. - Highlights: • Surface PEGylation of ND via RAFT polymerization. • ND with high water dispersibility and excellent biocompatibility. • Controlled living polymerization. - Abstract: Nanodiamond (ND) is a novel class of carbon nanomaterials, which has been extensively investigated for biomedical applications because of its small size, high surface area and excellent biocompatibility. However, the biomedical applications of unmodified ND are still largely restricted because of their poor dispersibility in both aqueous and organic medium. In this work, we reported a novel strategy for the surface modification of ND via reversible addition fragmentation chain transfer (RAFT) polymerization. For preparation of the PEGylated ND (pPEGMA-ND), chain transfer agent (CTA) was immobilized onto ND through reaction between the hydroxyl group of ND and the carboxyl group of CTA, which was used as the initiator for surface-initiated RAFT polymerization. The successful preparation of pPEGMA-ND was characterized by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectra and thermal gravimetric analysis in detail. Results demonstrated that pPEGMA-ND exhibited enhanced water dispersibility and desirable biocompatibility, making it promising for biomedical applications.

Direct surface PEGylation of nanodiamond via RAFT polymerization

Energy Technology Data Exchange (ETDEWEB)

Shi, Yingge [Department of Chemistry and Jiangxi Provincial Key Laboratory of New Energy Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Liu, Meiying [Department of Chemistry and Jiangxi Provincial Key Laboratory of New Energy Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Wang, Ke [Department of Chemistry and the Tsinghua Center for Frontier Polymer Research, Tsinghua University, Beijing 100084 (China); Huang, Hongye; Wan, Qing [Department of Chemistry and Jiangxi Provincial Key Laboratory of New Energy Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Tao, Lei [Department of Chemistry and the Tsinghua Center for Frontier Polymer Research, Tsinghua University, Beijing 100084 (China); Fu, Lihua [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Zhang, Xiaoyong, E-mail: xiaoyongzhang1980@gmail.com [Department of Chemistry and Jiangxi Provincial Key Laboratory of New Energy Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Wei, Yen, E-mail: weiyen@tsinghua.edu.cn [Department of Chemistry and the Tsinghua Center for Frontier Polymer Research, Tsinghua University, Beijing 100084 (China)

2015-12-01

Graphical abstract: In this paper, we describe an efficient, practical and novel method to modify ND via direct immobilization of chain transfer agent for RAFT polymerization. - Highlights: • Surface PEGylation of ND via RAFT polymerization. • ND with high water dispersibility and excellent biocompatibility. • Controlled living polymerization. - Abstract: Nanodiamond (ND) is a novel class of carbon nanomaterials, which has been extensively investigated for biomedical applications because of its small size, high surface area and excellent biocompatibility. However, the biomedical applications of unmodified ND are still largely restricted because of their poor dispersibility in both aqueous and organic medium. In this work, we reported a novel strategy for the surface modification of ND via reversible addition fragmentation chain transfer (RAFT) polymerization. For preparation of the PEGylated ND (pPEGMA-ND), chain transfer agent (CTA) was immobilized onto ND through reaction between the hydroxyl group of ND and the carboxyl group of CTA, which was used as the initiator for surface-initiated RAFT polymerization. The successful preparation of pPEGMA-ND was characterized by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectra and thermal gravimetric analysis in detail. Results demonstrated that pPEGMA-ND exhibited enhanced water dispersibility and desirable biocompatibility, making it promising for biomedical applications.

A comparison of photographic, replication and direct clinical examination methods for detecting developmental defects of enamel

Directory of Open Access Journals (Sweden)

Pakshir Hamid-Reza

2011-04-01

Full Text Available Abstract Background Different methods have been used for detecting developmental defects of enamel (DDE. This study aimed to compare photographic and replication methods with the direct clinical examination method for detecting DDE in children's permanent incisors. Methods 110 8-10-year-old schoolchildren were randomly selected from an examined sample of 335 primary Shiraz school children. Modified DDE index was used in all three methods. Direct examinations were conducted by two calibrated examiners using flat oral mirrors and tongue blades. Photographs were taken using a digital SLR camera (Nikon D-80, macro lens, macro flashes, and matt flash filters. Impressions were taken using additional-curing silicon material and casts made in orthodontic stone. Impressions and models were both assessed using dental loupes (magnification=x3.5. Each photograph/impression/cast was assessed by two calibrated examiners. Reliability of methods was assessed using kappa agreement tests. Kappa agreement, McNemar's and two-sample proportion tests were used to compare results obtained by the photographic and replication methods with those obtained by the direct examination method. Results Of the 110 invited children, 90 were photographed and 73 had impressions taken. The photographic method had higher reliability levels than the other two methods, and compared to the direct clinical examination detected significantly more subjects with DDE (P = 0.002, 3.1 times more DDE (P Conclusion The photographic method was much more sensitive than direct clinical examination in detecting DDE and was the best of the three methods for epidemiological studies. The replication method provided less information about DDE compared to photography. Results of this study have implications for both epidemiological and detailed clinical studies on DDE.

Examining Urban Impervious Surface Distribution and Its Dynamic Change in Hangzhou Metropolis

Directory of Open Access Journals (Sweden)

Longwei Li

2016-03-01

Full Text Available Analysis of urban distribution and its expansion using remote sensing data has received increasing attention in the past three decades, but little research has examined spatial patterns of urban distribution and expansion with buffer zones in different directions. This research selected Hangzhou metropolis as a case study to analyze spatial patterns and dynamic changes based on time-series urban impervious surface area (ISA datasets. ISA was developed from Landsat imagery between 1991 and 2014 using a hybrid approach consisting of linear spectral mixture analysis, decision tree classifiers, and post-processing. The spatial patterns of ISA distribution and its dynamic changes in eight directions—east, southeast, south, southwest, west, northwest, north, and northeast—at the temporal scale were analyzed with a buffer zone-based approach. This research indicated that ISA can be extracted from Landsat imagery with both producer and user accuracies of over 90%. ISA in Hangzhou metropolis increased from 146 km2 in 1991 to 868 km2 in 2014. Annual ISA growth rates were between 15.6 km2 and 48.8 km2 with the lowest growth rate in 1994–2000 and the highest growth rate in 2005–2010. Urban ISA increase before 2000 was mainly due to infilling within the urban landscape, and, after 2005, due to urban expansion in the urban-rural interfaces. Urban expansion in this study area has different characteristics in various directions that are influenced by topographic factors and urban development policies.

43 CFR 23.5 - Technical examination of prospective surface exploration and mining operations.

Science.gov (United States)

2010-10-01

... mining operations vary widely with respect to topography, climate, surrounding land uses, proximity to... surface exploration and mining operations. 23.5 Section 23.5 Public Lands: Interior Office of the Secretary of the Interior SURFACE EXPLORATION, MINING AND RECLAMATION OF LANDS § 23.5 Technical examination...

Directional radiative properties of anisotropic rough silicon and gold surfaces

Energy Technology Data Exchange (ETDEWEB)

Lee, H.J.; Chen, Y.B.; Zhang, Z.M. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

2006-11-15

Recent studies have shown that the topography of some chemically etched microrough silicon surfaces is non-Gaussian and may be strongly anisotropic. However, the bidirectional reflectance distribution function (BRDF) of anisotropic surfaces has not been fully understood. The present study uses the Monte Carlo method to investigate the out-of-plane BRDF, multiple scattering, and the change of the polarization state upon reflection. Two ray-tracing algorithms are developed that incorporate the surface topography or slope distribution of the samples obtained by the use of an atomic force microscope. The predicted BRDFs for silicon surfaces with or without a gold coating are in reasonable agreement with the results measured using a laser scatterometer at a wavelength of 635nm. The employment of surface topographic data is indispensable to the BRDF modeling of anisotropic surfaces. While first-order scattering makes the dominant contribution to reflections from the studied surfaces, it is critical to consider the polarization state change in order to correctly predict the out-of-plane BRDF. The versatile Monte Carlo modeling tools developed through the present study help gain a better understanding of the directional radiative properties of microrough surfaces and, furthermore, will have an impact on thermal metrology in the semiconductor industry. (author)

Entrance surface dose measurements in pediatric radiological examinations

International Nuclear Information System (INIS)

Ribeiro, L.A.; Yoshimura, E.M.

2008-01-01

A survey of pediatric radiological examinations was carried out in a reference pediatric hospital of the city of Sao Paulo, in order to investigate the doses to children undergoing conventional X-ray examinations. The results showed that the majority of pediatric patients are below 4 years, and that about 80% of the examinations correspond to chest projections. Doses to typical radiological examinations were measured in vivo with thermoluminescent dosimeters (LiF: Mg, Ti and LiF: Mg, Cu, P) attached to the skin of the children to determine entrance surface dose (ESD). Also homogeneous phantoms were used to obtain ESD to younger children, because the technique uses a so small kVp that the dosimeters would produce an artifact image in the patient radiograph. Four kinds of pediatric examinations were investigated: three conventional examinations (chest, skull and abdomen) and a fluoroscopic procedure (barium swallow). Relevant information about kVp and mAs values used in the examinations was collected, and we discuss how these parameters can affect the ESD. The ESD values measured in this work are compared to reference levels published by the European Commission for pediatric patients. The results obtained (third-quartile of the ESD distribution) for chest AP examinations in three age groups were: 0.056 mGy (2-4 years old); 0.068 mGy (5-9 years old); 0.069 mGy (10-15 years old). All of them are below the European reference level (0.100 mGy). ESD values measured to the older age group in skull and abdomen AP radiographs (mean values 3.44 and 1.20 mGy, respectively) are above the European reference levels (1.5 mGy to skull and 1.0 mGy to abdomen). ESD values measured in the barium swallow examination reached 10 mGy in skin regions corresponding to thyroid and esophagus. It was noticed during this survey that some technicians use, improperly, X-ray fluoroscopy in conventional examinations to help them in positioning the patient. The results presented here are a

Luminescence evolution from alumina ceramic surface before flashover under direct and alternating current voltage in vacuum

Energy Technology Data Exchange (ETDEWEB)

Su, Guo-Qiang; Wang, Yi-Bo; Song, Bai-Peng; Mu, Hai-Bao, E-mail: haibaomu@xjtu.edu.cn, E-mail: gjzhang@xjtu.edu.cn; Zhang, Guan-Jun, E-mail: haibaomu@xjtu.edu.cn, E-mail: gjzhang@xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Li, Feng; Wang, Meng [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China)

2016-06-15

The luminescence evolution phenomena from alumina ceramic surface in vacuum under high voltage of direct and alternating current are reported, with the voltage covering a large range from far below to close to the flashover voltage. Its time resolved and spatial distributed behaviors are examined by a photon counting system and an electron-multiplying charge-coupled device (EMCCD) together with a digital camera, respectively. The luminescence before flashover exhibits two stages as voltage increasing, i.e., under a relative low voltage (Stage A), the luminescence is ascribed to radiative recombination of hetero-charges injected into the sample surface layer by Schottky effect; under a higher voltage (Stage B), a stable secondary electron emission process, resulting from the Fowler-Nordheim emission at the cathode triple junction (CTJ), is responsible for the luminescence. Spectrum analysis implies that inner secondary electrons within the surface layer of alumina generated during the SSEE process also participate in the luminescence of Stage B. A comprehensive interpretation of the flashover process is formulated, which might promote a better understanding of flashover issue in vacuum.

Multisensor satellite data integration for sea surface wind speed and direction determination

Science.gov (United States)

Glackin, D. L.; Pihos, G. G.; Wheelock, S. L.

1984-01-01

Techniques to integrate meteorological data from various satellite sensors to yield a global measure of sea surface wind speed and direction for input to the Navy's operational weather forecast models were investigated. The sensors were launched or will be launched, specifically the GOES visible and infrared imaging sensor, the Nimbus-7 SMMR, and the DMSP SSM/I instrument. An algorithm for the extrapolation to the sea surface of wind directions as derived from successive GOES cloud images was developed. This wind veering algorithm is relatively simple, accounts for the major physical variables, and seems to represent the best solution that can be found with existing data. An algorithm for the interpolation of the scattered observed data to a common geographical grid was implemented. The algorithm is based on a combination of inverse distance weighting and trend surface fitting, and is suited to combing wind data from disparate sources.

Examination of fracture surfaces using focused ion beam milling

International Nuclear Information System (INIS)

Cairney, J.M.; Munroe, P.R.; Schneibel, J.H.

2000-01-01

Composite materials consisting of an iron aluminide matrix with composition approximately Fe-40at%Al, reinforced with a volume fraction of 40--70% ceramic particles (TiC, WC, TiB 2 or ZrB 2 ), are currently being developed. Focused ion beam milling is a relatively new tool to materials science. It uses a high resolution (<5nm), energetic beam of gallium ions to selectively sputter regions of a material, whilst also functioning as a scanning ion microscope. The milling accuracy is of the order of the beam size allowing very precise sectioning to be carried out. The focused ion beam can be used to prepare highly localized cross sections which reveal the internal sub-structure of materials, avoiding detrimental processes such as deformation, or closing of existing cracks by mechanical abrasion. An area is milled from the sample such that, upon tilting, the internal structure can be imaged. The focused ion beam therefore offers a unique opportunity to examine cross-sections of the fracture surfaces in FeAl-based composites. In the present study, the focused ion beam was used to obtain cross-sections of fracture surfaces in two composite materials, in order to examine the extent of interfacial debonding and matrix deformation, thus providing more information about the mode of fracture. These cross-sections were prepared at regions where significant debonding was observed

Surface modification of polyacrylonitrile co-polymer membranes using pulsed direct current nitrogen plasma

Energy Technology Data Exchange (ETDEWEB)

Pal, Dipankar; Neogi, Sudarsan; De, Sirshendu, E-mail: sde@che.iitkgp.ernet.in

2015-12-31

Low temperature plasma treatment using pulsed direct current discharge of nitrogen gas was employed to enhance hydrophilicity of the polyacrylonitrile co-polymer membranes. The membranes were characterized in terms of morphology, structure, hydrophilicity, and membrane performance. Properties and functional groups on the surface of polyacrylonitrile co-polymer membranes were investigated by contact angle, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Effects of plasma conditions, namely, pulsed voltage, duty cycle and treatment time on increase in membrane hydrophilicity were studied. Permeability of treated membrane was increased by 47% and it was retained up to 70 days. Surface etching due to plasma treatment was confirmed by weight loss of the treated membranes. Due to surface etching, average pore size increased and rejection of 200 kDa polyethylene glycol decreased to about 70% for the treated membrane. Oxygen and nitrogen functional groups were responsible for surface hydrophilicity. - Highlights: • Surface modification of polyacrylonitrile co-polymer membranes by pulsed direct current nitrogen plasma • Hydrophilic functional groups incorporated on the membrane surface • Significant enhancement of the permeability and wettability of the membranes • Water contact angle increased with storage time and finally stabilized.

Surface modification of polyacrylonitrile co-polymer membranes using pulsed direct current nitrogen plasma

International Nuclear Information System (INIS)

Pal, Dipankar; Neogi, Sudarsan; De, Sirshendu

2015-01-01

Low temperature plasma treatment using pulsed direct current discharge of nitrogen gas was employed to enhance hydrophilicity of the polyacrylonitrile co-polymer membranes. The membranes were characterized in terms of morphology, structure, hydrophilicity, and membrane performance. Properties and functional groups on the surface of polyacrylonitrile co-polymer membranes were investigated by contact angle, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Effects of plasma conditions, namely, pulsed voltage, duty cycle and treatment time on increase in membrane hydrophilicity were studied. Permeability of treated membrane was increased by 47% and it was retained up to 70 days. Surface etching due to plasma treatment was confirmed by weight loss of the treated membranes. Due to surface etching, average pore size increased and rejection of 200 kDa polyethylene glycol decreased to about 70% for the treated membrane. Oxygen and nitrogen functional groups were responsible for surface hydrophilicity. - Highlights: • Surface modification of polyacrylonitrile co-polymer membranes by pulsed direct current nitrogen plasma • Hydrophilic functional groups incorporated on the membrane surface • Significant enhancement of the permeability and wettability of the membranes • Water contact angle increased with storage time and finally stabilized.

Direct electrodeposition of metal nanowires on electrode surface

International Nuclear Information System (INIS)

Gambirasi, Arianna; Cattarin, Sandro; Musiani, Marco; Vazquez-Gomez, Lourdes; Verlato, Enrico

2011-01-01

A method for decorating the surface of disk electrodes with metal nanowires is presented. Cu and Ni nanowires with diameters from 1.0 μm to 0.2 μm are directly deposited on the electrode surface using a polycarbonate membrane filter template maintained in contact with the metal substrate by the soft homogeneous pressure of a sponge soaked with electrolyte. The morphologic and structural properties of the deposit are characterized by scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The latter shows that the head of nanowires with diameter of 0.4 μm is ordinarily polycrystalline, and that of nanowires with diameter of 0.2 μm is almost always monocrystalline for Cu and frequently also for Ni. Cyclic voltammetries and impedance investigations recorded in alkaline solutions at representative Ni electrodes decorated with nanowires provide consistent values of roughness factor, in the range 20-25.

NOx Direct Decomposition: Potentially Enhanced Thermodynamics and Kinetics on Chemically Modified Ferroelectric Surfaces

Science.gov (United States)

Kakekhani, Arvin; Ismail-Beigi, Sohrab

2014-03-01

NOx are regulated pollutants produced during automotive combustion. As part of an effort to design catalysts for NOx decomposition that operate in oxygen rich environment and permit greater fuel efficiency, we study chemistry of NOx on (001) ferroelectric surfaces. Changing the polarization at such surfaces modifies electronic properties and leads to switchable surface chemistry. Using first principles theory, our previous work has shown that addition of catalytic RuO2 monolayer on ferroelectric PbTiO3 surface makes direct decomposition of NO thermodynamically favorable for one polarization. Furthermore, the usual problem of blockage of catalytic sites by strong oxygen binding is overcome by flipping polarization that helps desorb the oxygen. We describe a thermodynamic cycle for direct NO decomposition followed by desorption of N2 and O2. We provide energy barriers and transition states for key steps of the cycle as well as describing their dependence on polarization direction. We end by pointing out how a switchable order parameter of substrate,in this case ferroelectric polarization, allows us to break away from some standard compromises for catalyst design(e.g. the Sabatier principle). This enlarges the set of potentially catalytic metals. Primary support from Toyota Motor Engineering and Manufacturing, North America, Inc.

Examining factors that influence the effectiveness of cleaning antineoplastic drugs from drug preparation surfaces: a pilot study.

Science.gov (United States)

Hon, Chun-Yip; Chua, Prescillia Ps; Danyluk, Quinn; Astrakianakis, George

2014-06-01

Occupational exposure to antineoplastic drugs has been documented to result in various adverse health effects. Despite the implementation of control measures to minimize exposure, detectable levels of drug residual are still found on hospital work surfaces. Cleaning these surfaces is considered as one means to minimize the exposure potential. However, there are no consistent guiding principles related to cleaning of contaminated surfaces resulting in hospitals to adopt varying practices. As such, this pilot study sought to evaluate current cleaning protocols and identify those factors that were most effective in reducing contamination on drug preparation surfaces. Three cleaning variables were examined: (1) type of cleaning agent (CaviCide®, Phenokil II™, bleach and chlorhexidine), (2) application method of cleaning agent (directly onto surface or indirectly onto a wipe) and (3) use of isopropyl alcohol after cleaning agent application. Known concentrations of antineoplastic drugs (either methotrexate or cyclophosphamide) were placed on a stainless steel swatch and then, systematically, each of the three cleaning variables was tested. Surface wipes were collected and quantified using high-performance liquid chromatography-tandem mass spectrometry to determine the percent residual of drug remaining (with 100% being complete elimination of the drug). No one single cleaning agent proved to be effective in completely eliminating all drug contamination. The method of application had minimal effect on the amount of drug residual. In general, application of isopropyl alcohol after the use of cleaning agent further reduced the level of drug contamination although measureable levels of drug were still found in some cases.

Examination of the effect of blowing on the near-surface flow structure over a dimpled surface

Science.gov (United States)

Borchetta, C. G.; Martin, A.; Bailey, S. C. C.

2018-03-01

The near surface flow over a dimpled surface with flow injection through it was documented using time-resolved particle image velocimetry. The instantaneous flow structure, time-averaged statistics, and results from snapshot proper orthogonal decomposition were used to examine the coherent structures forming near the dimpled surface. In particular, the modifications made to the flow structures by the addition of flow injection through the surface were studied. It was observed that without flow injection, inclined flow structures with alternating vorticity from neighboring dimples are generated by the dimples and advect downstream. This behavior is coupled with fluid becoming entrained inside the dimples, recirculating and ejecting away from the surface. When flow injection was introduced through the surface, the flow structures became more disorganized, but some of the features of the semi-periodic structures observed without flow injection were preserved. The structures with flow injection appear in multiple wall-normal layers, formed from vortical structures shed from upstream dimples, with a corresponding increase in the size of the advecting structures. As a result of the more complex flow field observed with flow injection, there was an increase in turbulent kinetic energy and Reynolds shear stress, with the Reynolds shear stress representing an increase in vertical transport of momentum by sweeping and ejecting motions that were not present without flow injection.

Patient surface doses in computerized tomography examinations

International Nuclear Information System (INIS)

Vekic, B.; Kovacevic, S.; Ranogajec Komor, M.; Duvnjak, N.; Marusic, P.; Anic, P.; Dolencic, P.

1996-01-01

Computed tomography (CT) has become a major source of the population exposure to diagnostic x-rays, and acknowledge of the doses delivered by the CT equipment has become very important. Considerable efforts should be made to keep these doses to a reasonable minimum, without sacrificing the image quality. The conditions of exposure in CT are quite different from dose in conventional x-ray imaging. This has required the development of specific techniques for assessing patient dose from CT. The aims of this work were to determine the dose delivered to various organs of patients undergoing computed tomography of abdomen, thorax, pelvis and kidney as measured on the surface of the body and to estimate the risk to the patients. Dosimetric measurements were performed at two different CT scanners (Siemens SOMATOM DR-H ver. HC-1 and Shimadzu SCT-4500TE). The dose absorbed by different organs (gonads, chest, thyroid and eye lens) and by the examined part of the body of 95 patients of various sex and age were measured with TLD-700. The doses absorbed by different organs during the diagnostic CT examination of the body depend on the technical parameters, such as the number of scan, mAs, the thickness of scans, scanning times, tube voltage and other characteristics, some of each depend on the type and severity of illness. Clinical parameters, such as patient size and composition, and patient cooperation with regard to the control and motion, also influence the dose and the image quality. The highest dose measured in this study (89.19 mGy) was delivered to kidney during CT examination of this organ. (author)

Frequency splitter based on the directional emission from surface modes in dielectric photonic crystal structures.

Science.gov (United States)

Tasolamprou, Anna C; Zhang, Lei; Kafesaki, Maria; Koschny, Thomas; Soukoulis, Costas M

2015-06-01

We demonstrate the numerical design and the experimental validation of frequency dependent directional emission from a dielectric photonic crystal structure. The wave propagates through a photonic crystal line-defect waveguide, while a surface layer at the termination of the photonic crystal enables the excitation of surface modes and a subsequent grating layer transforms the surface energy into outgoing propagating waves of the form of a directional beam. The angle of the beam is controlled by the frequency and the structure operates as a frequency splitter in the intermediate and far field region.

An Improved Local Gradient Method for Sea Surface Wind Direction Retrieval from SAR Imagery

Directory of Open Access Journals (Sweden)

Lizhang Zhou

2017-06-01

Full Text Available Sea surface wind affects the fluxes of energy, mass and momentum between the atmosphere and ocean, and therefore regional and global weather and climate. With various satellite microwave sensors, sea surface wind can be measured with large spatial coverage in almost all-weather conditions, day or night. Like any other remote sensing measurements, sea surface wind measurement is also indirect. Therefore, it is important to develop appropriate wind speed and direction retrieval models for different types of microwave instruments. In this paper, a new sea surface wind direction retrieval method from synthetic aperture radar (SAR imagery is developed. In the method, local gradients are computed in frequency domain by combining the operation of smoothing and computing local gradients in one step to simplify the process and avoid the difference approximation. This improved local gradients (ILG method is compared with the traditional two-dimensional fast Fourier transform (2D FFT method and local gradients (LG method, using interpolating wind directions from the European Centre for Medium-Range Weather Forecast (ECMWF reanalysis data and the Cross-Calibrated Multi-Platform (CCMP wind vector product. The sensitivities to the salt-and-pepper noise, the additive noise and the multiplicative noise are analyzed. The ILG method shows a better performance of retrieval wind directions than the other two methods.

Surface preparation for high purity alumina ceramics enabling direct brazing in hydrogen atmospheres

Science.gov (United States)

Cadden, Charles H.; Yang, Nancy Yuan Chi; Hosking, Floyd M.

2001-01-01

The present invention relates to a method for preparing the surface of a high purity alumina ceramic or sapphire specimen that enables direct brazing in a hydrogen atmosphere using an active braze alloy. The present invention also relates to a method for directly brazing a high purity alumina ceramic or sapphire specimen to a ceramic or metal member using this method of surface preparation, and to articles produced by this brazing method. The presence of silicon, in the form of a SiO.sub.2 -containing surface layer, can more than double the tensile bond strength in alumina ceramic joints brazed in a hydrogen atmosphere using an active Au-16Ni-0.75 Mo-1.75V filler metal. A thin silicon coating applied by PVD processing can, after air firing, produce a semi-continuous coverage of the alumina surface with a SiO.sub.2 film. Room temperature tensile strength was found to be proportional to the fraction of air fired surface covered by silicon-containing films. Similarly, the ratio of substrate fracture versus interface separation was also related to the amount of surface silicon present prior to brazing. This process can replace the need to perform a "moly-manganese" metallization step.

Synergistic cytotoxic effects of antibodies directed against different cell surface determinants

Energy Technology Data Exchange (ETDEWEB)

Elliott, E V; Pindar, A; Stevenson, F K; Stevenson, G T [Southampton General Hospital (UK). Tenovus Research Lab.

1978-03-01

Three antibody populations were raised in rabbits against surface antigens on guinea-pig L/sub 2/C leukaemic lymphocytes: against idiotypic determinants on the lambda chain of the surface immunoglobulin, against C region determinants on the lambda chain, and against the surface antigens recognised by conventional anti-lymphocyte sera. Complement and K-cell cytotoxicities effected by the antibodies on L/sub 2/C cells were studied in vitro. In both cytotoxic systems mixtures of the antibodies revealed synergy, in that the titres of the mixtures exceeded predicted additive titres of their components. The synergy was greater when the mixed antibodies were directed to determinants on the same molecule rather than to determinants on different molecules.

Assessing Impact Direction in 3-point Bending of Human Femora: Incomplete Butterfly Fractures and Fracture Surfaces,.

Science.gov (United States)

Isa, Mariyam I; Fenton, Todd W; Deland, Trevor; Haut, Roger C

2018-01-01

Current literature associates bending failure with butterfly fracture, in which fracture initiates transversely at the tensile surface of a bent bone and branches as it propagates toward the impact surface. The orientation of the resulting wedge fragment is often considered diagnostic of impact direction. However, experimental studies indicate bending does not always produce complete butterfly fractures or produces wedge fragments variably in tension or compression, precluding their use in interpreting directionality. This study reports results of experimental 3-point bending tests on thirteen unembalmed human femora. Complete fracture patterns varied following bending failure, but incomplete fractures and fracture surface characteristics were observed in all impacted specimens. A flat, billowy fracture surface was observed in tension, while jagged, angular peaks were observed in compression. Impact direction was accurately reconstructed using incomplete tension wedge butterfly fractures and tension and compression fracture surface criteria in all thirteen specimens. © 2017 American Academy of Forensic Sciences.

Examining the Support Peer Supporters Provide Using Structural Equation Modeling: Nondirective and Directive Support in Diabetes Management.

Science.gov (United States)

Kowitt, Sarah D; Ayala, Guadalupe X; Cherrington, Andrea L; Horton, Lucy A; Safford, Monika M; Soto, Sandra; Tang, Tricia S; Fisher, Edwin B

2017-12-01

Little research has examined the characteristics of peer support. Pertinent to such examination may be characteristics such as the distinction between nondirective support (accepting recipients' feelings and cooperative with their plans) and directive (prescribing "correct" choices and feelings). In a peer support program for individuals with diabetes, this study examined (a) whether the distinction between nondirective and directive support was reflected in participants' ratings of support provided by peer supporters and (b) how nondirective and directive support were related to depressive symptoms, diabetes distress, and Hemoglobin A1c (HbA1c). Three hundred fourteen participants with type 2 diabetes provided data on depressive symptoms, diabetes distress, and HbA1c before and after a diabetes management intervention delivered by peer supporters. At post-intervention, participants reported how the support provided by peer supporters was nondirective or directive. Confirmatory factor analysis (CFA), correlation analyses, and structural equation modeling examined the relationships among reports of nondirective and directive support, depressive symptoms, diabetes distress, and measured HbA1c. CFA confirmed the factor structure distinguishing between nondirective and directive support in participants' reports of support delivered by peer supporters. Controlling for demographic factors, baseline clinical values, and site, structural equation models indicated that at post-intervention, participants' reports of nondirective support were significantly associated with lower, while reports of directive support were significantly associated with greater depressive symptoms, altogether (with control variables) accounting for 51% of the variance in depressive symptoms. Peer supporters' nondirective support was associated with lower, but directive support was associated with greater depressive symptoms.

SEM examination and analysis of the interface character in surface modified aramid-epoxy composite

International Nuclear Information System (INIS)

Hussain, S.; Khan, M.B.; Hussain, R.

2011-01-01

The surface of Kevlar fibers is chemically modified by treatment with Phthalic anhydride (PA) and the effect is examined by SEM for the laser cut, three point bending and interlaminar shear delaminated surfaces. The surface modification improved the adhesion to epoxy resin that clearly leads to cohesive fracture as opposed to interfacial failure in the untreated specimen. SEM reveals marginal surface roughening of fibers without compromising their strength. The interface modification technique described in this paper is attractive thermodynamically as it does not compromise surface free energy of the polymer matrix or that of the fiber itself to enhance wet ability. (author)

Self-Assembled Nanocube-Based Plasmene Nanosheets as Soft Surface-Enhanced Raman Scattering Substrates toward Direct Quantitative Drug Identification on Surfaces.

Science.gov (United States)

Si, Kae Jye; Guo, Pengzhen; Shi, Qianqian; Cheng, Wenlong

2015-05-19

We report on self-assembled nanocube-based plasmene nanosheets as new surface-enhanced Raman scattering (SERS) substrates toward direct identification of a trace amount of drugs sitting on topologically complex real-world surfaces. The uniform nanocube arrays (superlattices) led to low spatial SERS signal variances (∼2%). Unlike conventional SERS substrates which are based on rigid nanostructured metals, our plasmene nanosheets are mechanically soft and optically semitransparent, enabling conformal attachment to real-world solid surfaces such as banknotes for direct SERS identification of drugs. Our plasmene nanosheets were able to detect benzocaine overdose down to a parts-per-billion (ppb) level with an excellent linear relationship (R(2) > 0.99) between characteristic peak intensity and concentration. On banknote surfaces, a detection limit of ∼0.9 × 10(-6) g/cm(2) benzocaine could be achieved. Furthermore, a few other drugs could also be identified, even in their binary mixtures with our plasmene nanosheets. Our experimental results clearly show that our plasmene sheets represent a new class of unique SERS substrates, potentially serving as a versatile platform for real-world forensic drug identification.

Dual brush process for selective surface modification in graphoepitaxy directed self-assembly

Science.gov (United States)

Doise, Jan; Chan, Boon Teik; Hori, Masafumi; Gronheid, Roel

2017-07-01

Graphoepitaxy directed self-assembly is a potential low-cost solution for patterning via layers with pitches beyond the reach of a single optical lithographic exposure. In this process, selective control of the interfacial energy at the bottom and sidewall of the template is an important but challenging exercise. A dual brush process is implemented, in which two brushes with distinct end-groups are consecutively grafted to the prepattern to achieve fully independent modification of the bottom and sidewall surface of the template. A comprehensive study of hole pattern quality shows that using a dual brush process leads to a substantial improvement in terms of positional and dimensional variability across the process window. These findings will be useful to others who wish to manipulate polymer-surface interactions in directed self-assembly flows.

Carbon out-diffusion mechanism for direct graphene growth on a silicon surface

International Nuclear Information System (INIS)

Kim, Byung-Sung; Lee, Jong Woon; Jang, Yamujin; Choi, Soon Hyung; Cha, Seung Nam; Sohn, Jung Inn; Kim, Jong Min; Joo, Won-Jae; Hwang, Sungwoo; Whang, Dongmok

2015-01-01

Direct growth of graphene on silicon (Si) through chemical vapor deposition has predominantly focused on surface-mediated processes due to the low carbon (C) solubility in Si. However, a considerable quantity of C atoms was incorporated in Si and formed Si 1−x C x alloy with a reduced lattice dimension even in the initial stage of direct graphene growth. Subsequent high temperature annealing promoted active C out-diffusion, resulting in the formation of a graphitic layer on the Si surface. Furthermore, the significantly low thermal conductivity of the Si 1−x C x alloy shows that the incorporated C atoms affect the properties of a semiconductor adjacent to the graphene. These findings provide a key guideline for controlling desirable properties of graphene and designing hybrid semiconductor/graphene architectures for various applications

Effect of nanoscale surface roughness on the bonding energy of direct-bonded silicon wafers

Science.gov (United States)

Miki, N.; Spearing, S. M.

2003-11-01

Direct wafer bonding of silicon wafers is a promising technology for manufacturing three-dimensional complex microelectromechanical systems as well as silicon-on-insulator substrates. Previous work has reported that the bond quality declines with increasing surface roughness, however, this relationship has not been quantified. This article explicitly correlates the bond quality, which is quantified by the apparent bonding energy, and the surface morphology via the bearing ratio, which describes the area of surface lying above a given depth. The apparent bonding energy is considered to be proportional to the real area of contact. The effective area of contact is defined as the area sufficiently close to contribute to the attractive force between the two bonding wafers. Experiments were conducted with silicon wafers whose surfaces were roughened by a buffered oxide etch solution (BOE, HF:NH4F=1:7) and/or a potassium hydroxide solution. The surface roughness was measured by atomic force microscopy. The wafers were direct bonded to polished "monitor" wafers following a standard RCA cleaning and the resulting bonding energy was measured by the crack-opening method. The experimental results revealed a clear correlation between the bonding energy and the bearing ratio. A bearing depth of ˜1.4 nm was found to be appropriate for the characterization of direct-bonded silicon at room temperature, which is consistent with the thickness of the water layer at the interface responsible for the hydrogen bonds that link the mating wafers.

Direct measurements of meltwater runoff on the Greenland ice sheet surface.

Science.gov (United States)

Smith, Laurence C; Yang, Kang; Pitcher, Lincoln H; Overstreet, Brandon T; Chu, Vena W; Rennermalm, Åsa K; Ryan, Jonathan C; Cooper, Matthew G; Gleason, Colin J; Tedesco, Marco; Jeyaratnam, Jeyavinoth; van As, Dirk; van den Broeke, Michiel R; van de Berg, Willem Jan; Noël, Brice; Langen, Peter L; Cullather, Richard I; Zhao, Bin; Willis, Michael J; Hubbard, Alun; Box, Jason E; Jenner, Brittany A; Behar, Alberto E

2017-12-12

Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-h trial for a 63.1-km 2 moulin-terminating internally drained catchment (IDC) on Greenland's midelevation (1,207-1,381 m above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6, RACMO2.3, MERRA-2, and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins but are improved using synthetic unit hydrograph (SUH) theory. Retroactive SUH applications to two older field studies reproduce their findings, signifying that remotely sensed IDC area, shape, and supraglacial river length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6, and RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment, models overestimated runoff by +21 to +58%, linked to overestimated surface ablation and possible meltwater retention in bare, porous, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of SMB with ice dynamics and subglacial systems. Copyright © 2017 the Author(s). Published by PNAS.

Direct measurements of meltwater runoff on the Greenland ice sheet surface

Science.gov (United States)

Smith, Laurence C.; Yang, Kang; Pitcher, Lincoln H.; Overstreet, Brandon T.; Chu, Vena W.; Rennermalm, Åsa K.; Ryan, Jonathan C.; Cooper, Matthew G.; Gleason, Colin J.; Tedesco, Marco; Jeyaratnam, Jeyavinoth; van As, Dirk; van den Broeke, Michiel R.; van de Berg, Willem Jan; Noël, Brice; Langen, Peter L.; Cullather, Richard I.; Zhao, Bin; Willis, Michael J.; Hubbard, Alun; Box, Jason E.; Jenner, Brittany A.; Behar, Alberto E.

2017-12-01

Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-h trial for a 63.1-km2 moulin-terminating internally drained catchment (IDC) on Greenland's midelevation (1,207–1,381 m above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6, RACMO2.3, MERRA-2, and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins but are improved using synthetic unit hydrograph (SUH) theory. Retroactive SUH applications to two older field studies reproduce their findings, signifying that remotely sensed IDC area, shape, and supraglacial river length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6, and RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment, models overestimated runoff by +21 to +58%, linked to overestimated surface ablation and possible meltwater retention in bare, porous, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of SMB with ice dynamics and subglacial systems.

Consistency of direct microscopic examination and ELISA in detection of Giardia in stool specimen among children

Directory of Open Access Journals (Sweden)

Zohreh Torabi

2014-09-01

Full Text Available Objective: To investigate the consistency of direct microscopic examination and ELISA for determination of Giadia in stool specimen. Method: Study population consisted of children with any clinical symptoms of Giardia infestation since last two weeks. Fresh stool specimen was collected from each child. The stools specimens were assessed by two methods of direct microscopic examination and ELISA.The degree of agreement between direct stool exam and ELISA was calculated by Cohen's kappa coefficient. Results: In this study, 124 children with age range 2-12 years were investigated. A total of 64 (61.7% and 79 (65.7% of children had Giardia by direct stool exam and ELISA test respectively. There was association between frequency of constipation and Giardia infection (P=0.036. The Cohen's kappa coefficient calculated for degree of agreement between direct stool exam and ELISA showed κ=0.756 (P<0.001. Conclusions: The frequency of Giardia infection in symptomatic children was high and there was high agreement rate between ELISA and direct stool smear.

An examination of surface epithelium structures of the embryo across the genus Poeciliopsis (Poeciliidae).

Science.gov (United States)

Panhuis, Tami M; Fris, Megan; Tuhela, Laura; Kwan, Lucia

2017-12-01

In viviparous, teleost fish, with postfertilization maternal nutrient provisioning, embryonic structures that facilitate maternal-fetal nutrient transfer are predicted to be present. For the family Poeciliidae, only a handful of morphological studies have explored these embryonic specializations. Here, we present a comparative morphological study in the viviparous poeciliid genus, Poeciliopsis. Using microscopy techniques, we examine the embryonic surface epidermis of Poeciliopsis species that vary in their level of postfertilization maternal nutrient provisioning and placentation across two phylogenetic clades and three independent evolutionary origins of placentation. We focus on surface features of the embryo that may facilitate maternal-fetal nutrient transfer. Specifically, we studied cell apical-surface morphology associated with the superficial epithelium that covers the body and sac (yolk and pericardial) of embryos at different developmental stages. Scanning electron microscopy revealed common surface epithelial cells across species, including pavement cells with apical-surface microridges or microvilli and presumed ionocytes and/or mucus-secreting cells. For three species, in the mid-stage embryos, the surface of the body and sac were covered in microvillus epithelium. The remaining species did not display microvillus epithelium at any of the stages examined. Instead, their epithelium of the body and sac were composed of cells with apical-surface microridges. For all species, in the late stage embryos, the surface of the body proper was composed of apical-surface microridges in a "fingerprint-like arrangement." Despite the differences in the surface epithelium of embryos across Poeciliopsis species and embryonic developmental stages, this variation was not associated with the level of postfertilization maternal nutrient provisioning. We discuss these results in light of previous morphological studies of matrotrophic, teleost fish, phylogenetic

Examining the decontaminability of surfaces from the beginnings of nuclear technology

International Nuclear Information System (INIS)

Kunze, S.

2003-01-01

Parallel with the development of nuclear technology in the 1950s, methods of examining the decontaminability of surface materials were elaborated, improved, and partly standardized in many countries. In 1988, ISO 8690 was adopted as an internationally accepted method of examination (technically identical to DIN 25 415, Part 1). A first range of coatings for nuclear applications were compiled from the large number of commercial products available on the market on the basis of the test method developed since 1962 at the Karlsruhe Nuclear Research Center and then at the Karlsruhe Research Center. Subsequently, the continuously improved test method was used to study, in mainly chemically curing two-component coatings, the reduction of gloss by dulling agents and fillers as well as various shades of color. Floor and container coatings were also examined for their resistance to radiation and to chemicals as well as wear. (orig.) [de

Adsorption of the diazo dye Direct Red 23 onto a zinc oxide surface: A spectroscopic study

Science.gov (United States)

Lucilha, Adriana Campano; Bonancêa, Carlos Eduardo; Barreto, Wagner José; Takashima, Keiko

2010-01-01

The adsorption of the diazo dye Direct Red 23 onto a zinc oxide surface at 30 °C in the dark was investigated. The color reduction was monitored by spectrophotometry at 503 nm. The FTIR and Raman spectra of the Direct Red 23 adsorption as a function of ZnO concentration were registered. From the PM3 semi-empirical calculations of the atomic charge density and dipole moment of the Direct Red 23 molecule, it was demonstrated that the azo dye molecule may be adsorbed onto the ZnO surface through molecule geometry modifications, enhancing the interfacial area causing a variation in the bonding frequencies.

Facile surface glycosylation of PVDF microporous membrane via direct surface-initiated AGET ATRP and improvement of antifouling property and biocompatibility

International Nuclear Information System (INIS)

Yuan Jing; Meng Jianqiang; Kang Yinlin; Du Qiyun; Zhang Yufeng

2012-01-01

This paper describes a facile and novel approach for the surface glycosylation of poly(vinylidene difluoride) (PVDF) microporous membrane. A glycopolymer poly(D-gluconamidoethyl methacrylate) (PGAMA) was tethered onto the membrane surface via activators generated by electron transfer atom transfer radical polymerization (AGET ATRP) directly initiated from the PVDF surface. Chemical changes of membrane surface were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). It was revealed that PGAMA was successfully grafted onto the membrane surface and its grafting density can be modulated in a wide range up to 2.4 μmol/cm 2 . The effects of glycosylation on membrane morphology, flux and surface hydrophilicity were investigated. Field emission scanning electron microscopy (FESEM) results indicated shrinkage of the surface pore diameters and the growth of the glycopolymer layer on the membrane surface. The static water contact angle (WCA) of the membrane surface decreased from 110° to 30.4° with the increase of grafting density, indicating that the PGAMA grafts dramatically improved the surface hydrophilicity. The protein adsorption and platelets adhesion experiments indicated that the grafted PGAMA could effectively improve the membrane antifouling property and biocompatibility.

Effectiveness of WRF wind direction for retrieving coastal sea surface wind from synthetic aperture radar

DEFF Research Database (Denmark)

Takeyama, Yuko; Ohsawa, Teruo; Kozai, Katsutoshi

2013-01-01

Wind direction is required as input to the geophysical model function (GMF) for the retrieval of sea surface wind speed from a synthetic aperture radar (SAR) images. The present study verifies the effectiveness of using the wind direction obtained from the weather research and forecasting model (...

Ultrafast directional beam switching in coupled vertical-cavity surface-emitting lasers

International Nuclear Information System (INIS)

Ning, C. Z.; Goorjian, P.

2001-01-01

We propose a strategy to performing ultrafast directional beam switching using two coupled vertical-cavity surface-emitting lasers (VCSELs). The proposed strategy is demonstrated for two VCSELs of 5.6 μm in diameter placed about 1 μm apart from the edges, showing a switching speed of 42 GHz with a maximum far-field angle span of about 10 degree. [copyright] 2001 American Institute of Physics

A theoretical and numerical study of polarimetric scattering and emission from random rough surfaces with anisotropic directional spectrum

Science.gov (United States)

Yueh, S. H.; Kwok, R.

1993-01-01

In this paper, theoretical and numerical results of the polarimetric scattering and emission from random rough surfaces with anisotropic directional spectrum are presented for the remote sensing of ocean and soil surfaces. The polarimetric scattered field for rough dielectric surfaces is derived to the second order by the small perturbation method (SPM). It is found that the second-order scattered field is coherent in nature, and its coefficients for different polarizations present the lowest-order corrections to the Fresnel reflection coefficients of the surfaces. In addition, the cross-polarized (HV and VH) components of the coherent fields are reciprocal and not zero for surfaces with anisotropic directional spectrum when the azimuth angle of the incident direction is not aligned with the symmetry directions of surfaces. In order to verify the energy conservation condition of the theoretical results, which is important if the theory is to be applied to the passive polarimetry of rough surfaces, a Monte Carlo simulation is performed to numerically calculate the polarimetric reflectivities of one-dimensional random rough surfaces which are generated with a prescribed power-law spectrum in the spectral domain and transformed to the spatial domain by the FFT. The surfaces simulated by this approach are periodic with the period corresponding to the low-wavenumber cutoff. To calculate the scattering from periodic dielectric surfaces, the authors present a new numerical technique which applies the Floquet theorem to reduce the problem to one period and does not require the evaluation of one-dimensional periodic Green's function used in the conventional method of moment formulation. Once the scattering coefficients are obtained, the polarimetric Stokes vectors for the emission from the random surfaces are then calculated according to the Kirchhoff's law and are illustrated as functions of relative azimuth observation and row directions. The second-order SPM is also

Direct transfer of multilayer graphene grown on a rough metal surface using PDMS adhesion engineering

Science.gov (United States)

Jang, Heejun; Kang, Il-Suk; Lee, Youngbok; Cha, Yun Jeong; Yoon, Dong Ki; Ahn, Chi Won; Lee, Wonhee

2016-09-01

The direct transfer of graphene using polydimethylsiloxane (PDMS) stamping has advantages such as a ‘pick-and-place’ capability and no chemical residue problems. However, it is not easy to apply direct PDMS stamping to graphene grown via chemical vapor deposition on rough, grainy metal surfaces due to poor contact between the PDMS and graphene. In this study, graphene consisting of a mixture of monolayers and multiple layers grown on a rough Ni surface was directly transferred without the use of an adhesive layer. Liquid PDMS was cured on graphene to effect a conformal contact with the graphene. A fast release of graphene from substrate was achieved by carrying out wet-etching-assisted mechanical peeling. We also carried out a thermal post-curing of PDMS to control the level of adhesion between PDMS and graphene and hence facilitate a damage-free release of the graphene. Characterization of the transferred graphene by micro-Raman spectroscopy, SEM/EDS and optical microscopy showed neither cracks nor contamination from the transfer. This technique allows a fast and simple transfer of graphene, even for multilayer graphene grown on a rough surface.

Direct observation of surface reconstruction and termination on a complex metal oxide catalyst by electron microscopy

KAUST Repository

Zhu, Yihan

2012-03-19

On the surface: The surface reconstruction of an MoVTeO complex metal oxide catalyst was observed directly by various electron microscopic techniques and the results explain the puzzling catalytic behavior. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of anti-theft devices directly from the surface of banknotes via easy ambient sonic spray ionization mass spectrometry.

Science.gov (United States)

Schmidt, Eduardo Morgado; Franco, Marcos Fernando; Cuelbas, Claudio José; Zacca, Jorge Jardim; de Carvalho Rocha, Werickson Fortunato; Borges, Rodrigo; de Souza, Wanderley; Sawaya, Alexandra Christine Helena Frankland; Eberlin, Marcos Nogueira; Correa, Deleon Nascimento

2015-09-01

Using Brazilian banknotes as a test case, forensic examination and identification of Rhodamine B dye anti-theft device (ATD) staining on banknotes were performed. Easy ambient sonic spray ionization mass spectrometry (EASI-MS) was used since it allows fast and simple analysis with no sample preparation providing molecular screening of the surface with direct desorption and ionization of the security dye. For a more accurate molecular characterization of the ATD dye, Q Exactive Orbitrap™ Fourier transform (tandem) mass spectrometry using eletrospray ionization (ESI-HRMS/MS) was also applied. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

Examination of soldier target recognition with direct view optics

Science.gov (United States)

Long, Frederick H.; Larkin, Gabriella; Bisordi, Danielle; Dorsey, Shauna; Marianucci, Damien; Goss, Lashawnta; Bastawros, Michael; Misiuda, Paul; Rodgers, Glenn; Mazz, John P.

2017-10-01

Target recognition and identification is a problem of great military and scientific importance. To examine the correlation between target recognition and optical magnification, ten U.S. Army soldiers were tasked with identifying letters on targets at 800 and 1300 meters away. Letters were used since they are a standard method for measuring visual acuity. The letters were approximately 90 cm high, which is the size of a well-known rifle. Four direct view optics with angular magnifications of 1.5x, 4x, 6x, and 9x were used. The goal of this approach was to measure actual probabilities for correct target identification. Previous scientific literature suggests that target recognition can be modeled as a linear response problem in angular frequency space using the established values for the contrast sensitivity function for a healthy human eye and the experimentally measured modulation transfer function of the optic. At the 9x magnification, the soldiers could identify the letters with almost no errors (i.e., 97% probability of correct identification). At lower magnification, errors in letter identification were more frequent. The identification errors were not random but occurred most frequently with a few pairs of letters (e.g., O and Q), which is consistent with the literature for letter recognition. In addition, in the small subject sample of ten soldiers, there was considerable variation in the observer recognition capability at 1.5x and a range of 800 meters. This can be directly attributed to the variation in the observer visual acuity.

Direct Observation of Domain-Wall Surface Tension by Deflating or Inflating a Magnetic Bubble

Science.gov (United States)

Zhang, Xueying; Vernier, Nicolas; Zhao, Weisheng; Yu, Haiming; Vila, Laurent; Zhang, Yue; Ravelosona, Dafiné

2018-02-01

The surface energy of a magnetic domain wall (DW) strongly affects its static and dynamic behaviors. However, this effect is seldom directly observed, and some of the related phenomena are not well understood. Moreover, a reliable method to quantify the DW surface energy is still absent. Here, we report a series of experiments in which the DW surface energy becomes a dominant parameter. We observe that a semicircular magnetic domain bubble can spontaneously collapse under the Laplace pressure induced by DW surface energy. We further demonstrate that the surface energy can lead to a geometrically induced pinning when the DW propagates in a Hall cross or from a nanowire into a nucleation pad. Based on these observations, we develop two methods to quantify the DW surface energy, which can be very helpful in the estimation of intrinsic parameters such as Dzyaloshinskii-Moriya interactions or exchange stiffness in magnetic ultrathin films.

Finding shortest non-trivial cycles in directed graphs on surfaces

Directory of Open Access Journals (Sweden)

Sergio Cabello

2016-04-01

Full Text Available Let $D$ be a weighted directed graph cellularly embedded in a surface of genus $g$, orientable or not, possibly with boundary.  We describe algorithms to compute shortest non-contractible and shortest surface non-separating cycles in $D$, generalizing previous results that dealt with undirected graphs.Our first algorithm computes such cycles in $O(n^2\\log n$ time, where $n$ is the total number of vertices and edges of $D$, thus matching the complexity of the best general algorithm in the undirected case.  It revisits and extends Thomassen's 3-path condition; the technique applies to other families of cycles as well.We also provide more efficient algorithms in special cases, such as graphs with small genus or bounded treewidth, using a divide-and-conquer technique that simplifies the graph while preserving the topological properties of its cycles.  Finally, we give an efficient output-sensitive algorithm, whose running time depends on the length of the shortest non-contractible or non-separating cycle.

Measurement of the sea surface wind speed and direction by an airborne microwave radar altimeter

Energy Technology Data Exchange (ETDEWEB)

Nekrassov, A. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Hydrophysik

2001-07-01

A pilot needs operational information about wind over sea as well as wave height to provide safety of a hydroplane landing on water. Near-surface wind speed and direction can be obtained with an airborne microwave scatterometer, radar designed for measuring the scatter characteristics of a surface. Mostly narrow-beam antennas are applied for such wind measurement. Unfortunately, a microwave narrow-beam antenna has considerable size that hampers its placing on flying apparatus. In this connection, a possibility to apply a conventional airborne radar altimeter as a scatterometer with a nadir-looking wide-beam antenna in conjunction with Doppler filtering for recovering the wind vector over sea is discussed, and measuring algorithms of sea surface wind speed and direction are proposed. The obtained results can be used for creation of an airborne radar system for operational measurement of the sea roughness characteristics and for safe landing of a hydroplane on water. (orig.)

Direct synthesis of sp-bonded carbon chains on graphite surface by femtosecond laser irradiation

International Nuclear Information System (INIS)

Hu, A.; Rybachuk, M.; Lu, Q.-B.; Duley, W. W.

2007-01-01

Microscopic phase transformation from graphite to sp-bonded carbon chains (carbyne) and nanodiamond has been induced by femtosecond laser pulses on graphite surface. UV/surface enhanced Raman scattering spectra and x-ray photoelectron spectra displayed the local synthesis of carbyne in the melt zone while nanocrystalline diamond and trans-polyacetylene chains form in the edge area of gentle ablation. These results evidence possible direct 'writing' of variable chemical bonded carbons by femtosecond laser pulses for carbon-based applications

Urban Surface Temperature Reduction via the Urban Aerosol Direct Effect: A Remote Sensing and WRF Model Sensitivity Study

Directory of Open Access Journals (Sweden)

Menglin Jin

2010-01-01

Full Text Available The aerosol direct effect, namely, scattering and absorption of sunlight in the atmosphere, can lower surface temperature by reducing surface insolation. By combining National Aeronautics and Space Administration (NASA AERONET (AErosol RObotic NETwork observations in large cities with Weather Research and Forecasting (WRF model simulations, we find that the aerosol direct reduction of surface insolation ranges from 40–100Wm−2, depending on aerosol loading and land-atmosphere conditions. To elucidate the maximum possible effect, values are calculated using a radiative transfer model based on the top quartile of the multiyear instantaneous aerosol data observed by AERONET sites. As a result, surface skin temperature can be reduced by 1°C-2°C while 2-m surface air temperature reductions are generally on the order of 0.5°C–1°C.

UV Direct Laser Interference Patterning of polyurethane substrates as tool for tuning its surface wettability

Energy Technology Data Exchange (ETDEWEB)

Estevam-Alves, Regina [Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970 São Carlos (Brazil); Günther, Denise; Dani, Sophie; Eckhardt, Sebastian; Roch, Teja [Fraunhofer Institute for Material and Beam Technology IWS, Winterbergstr. 28, Dresden 01277 (Germany); Chair for Large Area Laser Based Surface Micro/Nano-Structuring, Institute for Manufacturing Technology, Technische Universität Dresden, George-Bähr-Str. 3c, 01069 Dresden (Germany); Mendonca, Cleber R., E-mail: crmendon@ifsc.usp.br [Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970 São Carlos (Brazil); Cestari, Ismar N. [Heart Institute (InCOr), University of São Paulo Medical School, São Paulo 05403-000 (Brazil); Lasagni, Andrés F., E-mail: andres_fabian.lasagni@tu-dresden.de [Fraunhofer Institute for Material and Beam Technology IWS, Winterbergstr. 28, Dresden 01277 (Germany); Chair for Large Area Laser Based Surface Micro/Nano-Structuring, Institute for Manufacturing Technology, Technische Universität Dresden, George-Bähr-Str. 3c, 01069 Dresden (Germany)

2016-06-30

Highlights: • First reported experiments on Direct Laser Interference Patterning of polyurethane. • First reported sub-micrometer structures (feature size ∼250 nm) fabricated in polyurethane materials using laser processing technologies. • Anisotropic wetting behavior of structured surfaces and possibility to tune the contact angle as function of surface structure parameters. - Abstract: Direct Laser Interference Patterning (DLIP) is a versatile tool for the fabrication of micro and sub-micropatterns on different materials. In this work, DLIP was used to produce periodic surface structures on polyurethane (PU) substrates with spatial periods ranging from 0.5 to 5.0 μm. The influence of the laser energy density on the quality and topographical characteristics of the produced micropatterns was investigated. To characterize the surface topography of the produced structures, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Confocal Microscopy (CFM) were utilized. It was found that high quality and defect free periodic line-like patterns with spatial periods down to 500 nm could be fabricated, with structure depths between 0.88 up to 1.25 μm for spatial periods larger than 2.0 μm and up to 270 nm for spatial periods between 500 nm and 1.0 μm. Measurements of the contact angle of water on the treated surface allowed to identify an anisotropic wetting behavior depending mainly on the spatial period and filling factor of the structured surfaces.

Direct investigation of (sub-) surface preparation artifacts in GaAs based materials by FIB sectioning

Energy Technology Data Exchange (ETDEWEB)

Belz, Jürgen; Beyer, Andreas; Torunski, Torsten; Stolz, Wolfgang; Volz, Kerstin

2016-04-15

The introduction of preparation artifacts is almost inevitable when producing samples for (scanning) transmission electron microscopy ((S)TEM). These artifacts can be divided in extrinsic artifacts like damage processes and intrinsic artifacts caused by the deviations from the volume strain state in thin elastically strained material systems. The reduction and estimation of those effects is of great importance for the quantitative analysis of (S)TEM images. Thus, optimized ion beam preparation conditions are investigated for high quality samples. Therefore, the surface topology is investigated directly with atomic force microscopy (AFM) on the actual TEM samples. Additionally, the sectioning of those samples by a focused ion beam (FIB) is used to investigate the damage depth profile directly in the TEM. The AFM measurements show good quantitative agreement of sample height modulation due to strain relaxation to finite elements simulations. Strong indications of (sub-) surface damage by ion beams are observed. Their influence on high angle annular dark field (HAADF) imaging is estimated with focus on thickness determination by absolute intensity methods. Data consolidation of AFM and TEM measurements reveals a 3.5 nm surface amorphization, negligible surface roughness on the scale of angstroms and a sub-surface damage profile in the range of up to 8.0 nm in crystalline gallium arsenide (GaAs) and GaAs-based ternary alloys. A correction scheme for thickness evaluation of absolute HAADF intensities is proposed and applied for GaAs based materials. - Highlights: • The damage by Ar-ion milling during TEM sample preparation is investigated directly. • After FIB sectioning damage and deep disorder of c-GaAs is seen in cross-section. • The influence of such disorder on conventional ADF measurements is estimated. • A correction for HAADF measurements is proposed with focus on thickness estimations.

Effects of piston surface treatments on performance and emissions of a methanol-fueled, direct injection, stratified charge engine

Energy Technology Data Exchange (ETDEWEB)

West, B.; Green, J.B. [Oak Ridge National Lab., TN (United States)

1994-07-01

The purpose of this study was to investigate the effects of thermal barrier coatings and/or surface treatments on the performance and emissions of a methanol-fueled, direct-injection, stratified-charge (DISC) engine. A Ricardo Hydra Mark III engine was used for this work and in previous experiments at Oak Ridge National Laboratory (ORNL). The primary focus of the study was to examine the effects of various piston insert surface treatments on hydrocarbon (HC) and oxides of nitrogen (NO{sub x}) emissions. Previous studies have shown that engines of this class have a tendency to perform poorly at low loads and have high unburned fuel emissions. A blank aluminum piston was modified to employ removable piston bowl inserts. Four different inserts were tested in the experiment: aluminum, stainless steel with a 1.27-mm (0.050-in.) air gap (to act as a thermal barrier), and two stainless steel/air-gap inserts with coatings. Two stainless steel inserts were dimensionally modified to account for the coating thickness (1.27-mm) and coated identically with partially stabilized zirconia (PSZ). One of the coated inserts then had an additional seal-coat applied. The coated inserts were otherwise identical to the stainless steel/air-gap insert (i.e., they employed the same 1.27-mm air gap). Thermal barrier coatings were employed in an attempt to increase combustion chamber surface temperatures, thereby reducing wall quenching and promoting more complete combustion of the fuel in the quench zone. The seal-coat was applied to the zirconia to reduce the surface porosity; previous research suggested that despite the possibly higher surface temperatures obtainable with a ceramic coating, the high surface area of a plasma-sprayed coating may actually allow fuel to adhere to the surface and increase the unburned fuel emissions and fuel consumption.

Protein consensus-based surface engineering (ProCoS): a computer-assisted method for directed protein evolution.

Science.gov (United States)

Shivange, Amol V; Hoeffken, Hans Wolfgang; Haefner, Stefan; Schwaneberg, Ulrich

2016-12-01

Protein consensus-based surface engineering (ProCoS) is a simple and efficient method for directed protein evolution combining computational analysis and molecular biology tools to engineer protein surfaces. ProCoS is based on the hypothesis that conserved residues originated from a common ancestor and that these residues are crucial for the function of a protein, whereas highly variable regions (situated on the surface of a protein) can be targeted for surface engineering to maximize performance. ProCoS comprises four main steps: ( i ) identification of conserved and highly variable regions; ( ii ) protein sequence design by substituting residues in the highly variable regions, and gene synthesis; ( iii ) in vitro DNA recombination of synthetic genes; and ( iv ) screening for active variants. ProCoS is a simple method for surface mutagenesis in which multiple sequence alignment is used for selection of surface residues based on a structural model. To demonstrate the technique's utility for directed evolution, the surface of a phytase enzyme from Yersinia mollaretii (Ymphytase) was subjected to ProCoS. Screening just 1050 clones from ProCoS engineering-guided mutant libraries yielded an enzyme with 34 amino acid substitutions. The surface-engineered Ymphytase exhibited 3.8-fold higher pH stability (at pH 2.8 for 3 h) and retained 40% of the enzyme's specific activity (400 U/mg) compared with the wild-type Ymphytase. The pH stability might be attributed to a significantly increased (20 percentage points; from 9% to 29%) number of negatively charged amino acids on the surface of the engineered phytase.

Wind speed and direction shears with associated vertical motion during strong surface winds

Science.gov (United States)

Alexander, M. B.; Camp, D. W.

1984-01-01

Strong surface winds recorded at the NASA 150-Meter Ground Winds Tower facility at Kennedy Space Center, Florida, are analyzed to present occurrences representative of wind shear and vertical motion known to be hazardous to the ascent and descent of conventional aircraft and the Space Shuttle. Graphical (percentage frequency distributions) and mathematical (maximum, mean, standard deviation) descriptions of wind speed and direction shears and associated updrafts and downdrafts are included as functions of six vertical layers and one horizontal distance for twenty 5-second intervals of parameters sampled simultaneously at the rate of ten per second during a period of high surface winds.

Measurement of Near-Surface Salinity, Temperature and Directional Wave Spectra using a Novel Wave-Following, Lagrangian Surface Contact Buoy

Science.gov (United States)

Boyle, J. P.

2016-02-01

Results from a surface contact drifter buoy which measures near-surface conductivity ( 10 cm depth), sea state characteristics and near-surface water temperature ( 2 cm depth) are described. This light (righting. It has a small above-surface profile and low windage, resulting in near-Lagrangian drift characteristics. It is autonomous, with low power requirements and solar panel battery recharging. Onboard sensors include an inductive toroidal conductivity probe for salinity measurement, a nine-degrees-of-freedom motion package for derivation of directional wave spectra and a thermocouple for water temperature measurement. Data retrieval for expendable, ocean-going operation uses an onboard Argos transmitter. Scientific results as well as data processing algorithms are presented from laboratory and field experiments which support qualification of buoy platform measurements. These include sensor calibration experiments, longer-term dock-side biofouling experiments during 2013-2014 and a series of short-duration ocean deployments in the Gulf Stream in 2014. In addition, a treatment method will be described which appears to minimize the effects of biofouling on the inductive conductivity probe when in coastal surface waters. Due to its low cost and ease of deployment, scores, perhaps hundreds of these novel instruments could be deployed from ships or aircraft during process studies or to provide surface validation for satellite-based measurements, particularly in high precipitation regions.

Directed Evolution to Engineer Monobody for FRET Biosensor Assembly and Imaging at Live-Cell Surface.

Science.gov (United States)

Limsakul, Praopim; Peng, Qin; Wu, Yiqian; Allen, Molly E; Liang, Jing; Remacle, Albert G; Lopez, Tyler; Ge, Xin; Kay, Brian K; Zhao, Huimin; Strongin, Alex Y; Yang, Xiang-Lei; Lu, Shaoying; Wang, Yingxiao

2018-04-19

Monitoring enzymatic activities at the cell surface is challenging due to the poor efficiency of transport and membrane integration of fluorescence resonance energy transfer (FRET)-based biosensors. Therefore, we developed a hybrid biosensor with separate donor and acceptor that assemble in situ. The directed evolution and sequence-function analysis technologies were integrated to engineer a monobody variant (PEbody) that binds to R-phycoerythrin (R-PE) dye. PEbody was used for visualizing the dynamic formation/separation of intercellular junctions. We further fused PEbody with the enhanced CFP and an enzyme-specific peptide at the extracellular surface to create a hybrid FRET biosensor upon R-PE capture for monitoring membrane-type-1 matrix metalloproteinase (MT1-MMP) activities. This biosensor revealed asymmetric distribution of MT1-MMP activities, which were high and low at loose and stable cell-cell contacts, respectively. Therefore, directed evolution and rational design are promising tools to engineer molecular binders and hybrid FRET biosensors for monitoring molecular regulations at the surface of living cells. Copyright © 2018 Elsevier Ltd. All rights reserved.

On Surface Losses in Direct Metal Laser Sintering Printed Millimeter and Submillimeter Waveguides

Science.gov (United States)

Holmberg, Max; Dancila, Dragos; Rydberg, Anders; Hjörvarsson, Björgvin; Jansson, Ulf; Marattukalam, Jithin James; Johansson, Niklas; Andersson, Joakim

2018-06-01

Different lengths of WR3 (220-330 GHz) and WR10 (75-110 GHz) waveguides are fabricated through direct metal laser sintering (DMLS). The losses in these waveguides are measured and modelled using the Huray surface roughness model. The losses in WR3 are around 0.3 dB/mm and in WR10 0.05 dB/mm. The Huray equation model is accounting relatively good for the attenuation in the WR10 waveguide but deviates more in the WR3 waveguide. The model is compared to finite element simulations of the losses assuming an approximate surface structure similar to the resulting one from the DMLS process.

Direct Observation of Double Hydrogen Transfer via Quantum Tunneling in a Single Porphycene Molecule on a Ag(110) Surface.

Science.gov (United States)

Koch, Matthias; Pagan, Mark; Persson, Mats; Gawinkowski, Sylwester; Waluk, Jacek; Kumagai, Takashi

2017-09-13

Quantum tunneling of hydrogen atoms (or protons) plays a crucial role in many chemical and biological reactions. Although tunneling of a single particle has been examined extensively in various one-dimensional potentials, many-particle tunneling in high-dimensional potential energy surfaces remains poorly understood. Here we present a direct observation of a double hydrogen atom transfer (tautomerization) within a single porphycene molecule on a Ag(110) surface using a cryogenic scanning tunneling microscope (STM). The tautomerization rates are temperature independent below ∼10 K, and a large kinetic isotope effect (KIE) is observed upon substituting the transferred hydrogen atoms by deuterium, indicating that the process is governed by tunneling. The observed KIE for three isotopologues and density functional theory calculations reveal that a stepwise transfer mechanism is dominant in the tautomerization. It is also found that the tautomerization rate is increased by vibrational excitation via an inelastic electron tunneling process. Moreover, the STM tip can be used to manipulate the tunneling dynamics through modification of the potential landscape.

Direct numerical simulation of turbulent channel flow over a liquid-infused micro-grooved surface

Science.gov (United States)

Chang, Jaehee; Jung, Taeyong; Choi, Haecheon; Kim, John

2016-11-01

Recently a superhydrophobic surface has drawn much attention as a passive device to achieve high drag reduction. Despite the high performance promised at ideal conditions, maintaining the interface in real flow conditions is an intractable problem. A non-wetting surface, known as the slippery liquid-infused porous surface (SLIPS) or the lubricant-impregnated surface (LIS), has shown a potential for drag reduction, as the working fluid slips at the interface but cannot penetrate into the lubricant layer. In the present study, we perform direct numerical simulation of turbulent channel flow over a liquid-infused micro-grooved surface to investigate the effects of this surface on the interfacial slip and drag reduction. The flow rate of water is maintained constant corresponding to Reτ 180 in a fully developed turbulent channel flow, and the lubricant layer is shear-driven by the turbulent water flow. The lubricant layer is also simulated with the assumption that the interface is flat (i.e. the surface tension effect is neglected). The solid substrate in which the lubricant is infused is modelled as straight ridges using an immersed boundary method. DNS results show that drag reduction by the liquid-infused surface is highly dependent on the viscosity of the lubricant.

Ultrasonic pumping of liquids in the two directions of a vertical tube by a vibrating surface

DEFF Research Database (Denmark)

Santillan, Arturo Orozco; Cutanda Henriquez, Vicente

2010-01-01

of the oscillations of the vibrating horizontal surface determine the direction in which the liquid is pumped. In addition, the size of the gap is also a relevant factor, which has to be significantly small. The carried out numerical simulations show that the Lagrangian excess pressure and the density of linear......It has been reported that it is possible to pump a liquid into the interior of a vertical pipe when its lower end is facing a vibrating plane surface immersed in the liquid. The column of liquid pumped in a thin pipe can be higher than 2 m if the gap between the pipe end and the vibrating...... horizontal surface is very small, around 0.01 mm. In this paper we present experimental results showing that, with a similar set up as the one mentioned above, it is also possible to pump liquids in the opposite direction, from the interior of the pipe through the gap. The general objective of the work has...

Direct observation of deformation of nafion surfaces induced by methanol treatment by using atomic force microscopy

International Nuclear Information System (INIS)

Umemura, Kazuo; Kuroda, Reiko; Gao Yanfeng; Nagai, Masayuki; Maeda, Yuta

2008-01-01

We successfully characterized the effect of methanol treatment on the nanoscopic structures of a nafion film, which is widely used in direct methanol fuel cells (DMFCs). Atomic force microscopy (AFM) was used to repetitively image a particular region of a nafion sample before and after methanol solutions were dropped onto the nafion film and dried in air. When the surface was treated with 20% methanol for 5 min, many nanopores appeared on the surface. The number of nanopores increased when the sample was treated twice or thrice. By repetitive AFM imaging of a particular region of the same sample, we found that the shapes of the nanopores were deformed by the repeated methanol treatment, although the size of the nanopores had not significantly changed. The creation of the nanopores was affected by the concentration of methanol. Our results directly visualized the effects of methanol treatment on the surface structures of a nafion film at nanoscale levels for the first time

Feedrate optimization in 5-axis machining based on direct trajectory interpolation on the surface using an open cnc

OpenAIRE

Beudaert , Xavier; Lavernhe , Sylvain; Tournier , Christophe

2014-01-01

International audience; In the common machining process of free-form surfaces, CAM software generates approximated tool paths because of the input tool path format of the industrial CNC. Then, marks on finished surfaces may appear due to non smooth feedrate planning during interpolation. The Direct Trajectory Interpolation on the Surface (DTIS) method allows managing the tool path geometry and the kinematical parameters to achieve higher productivity and a better surface quality. Machining ex...

Nondestructive examination

International Nuclear Information System (INIS)

Mletzko, U.

1980-01-01

Visual examination is treated as a method for the control of size and shape of components, surface quality and weld performance. Dye penetrant, magnetic particle and eddy current examinations are treated as methods for the evaluation of surface defects and material properties. The limitations to certain materials, defect sizes and types are shown. (orig./RW)

A directional entrapment modification on the polyethylene surface by the amphiphilic modifier of stearyl-alcohol poly(ethylene oxide) ether

Science.gov (United States)

Lu, Qiang; Chen, Yi; Huang, Juexin; Huang, Jian; Wang, Xiaolin; Yao, Jiaying

2018-05-01

A novel entrapment modification method involving directional implantation of the amphiphilic modifier of stearyl-alcohol poly(ethylene oxide) ether (AEO) into the high-density polyethylene (HDPE) surface is proposed. This modification technique allows the AEO modifier to be able to spontaneously attain and subsequently penetrate into the swollen HDPE surface with its hydrophobic stearyl segment, while its hydrophilic poly(ethylene oxide) (PEO) segment spontaneously points to water. The AEO modifier with a HLB number below 8.7 was proved appropriate for the directional entrapment, Nevertheless, AEOs with larger HLB numbers were also effective modifiers in the presence of salt additives. In addition, a larger and hydrophobic micelle, induced respectively by the AEO concentration above 1.3 × 10-2 mol/L and the entrapping temperature above the cloud point of AEO, could lead to a sharp contact angle decline of the modified surface. Finally, a hydrophilic HDPE surface with the modifier coverage of 38.9% was reached by the directional entrapment method, which is far larger than that of 19.2% by the traditional entrapment method.

A new holder and surface MRI coil for the examination of the newborn infant hip

Energy Technology Data Exchange (ETDEWEB)

Krasny, R. (Dept. of Diagnostic Radiology, Univ. of Technology, Aachen (Germany)); Casser, H.R. (Dept. of Orthopedics, Univ. of Technology, Aachen (Germany)); Requardt, H. (Siemens AG, Erlangen (Germany)); Botschek, A. (Dept. of Diagnostic Radiology, Univ. of Technology, Aachen (Germany))

1993-11-01

A special holder was developed for examination of the infant hip joint using MRI. This holder allows the infant hip joint to be examined both in a neutral position and in various defined functional positions. A special integrated surface coil, also developed for this purpose, provides the high spatial resolution required for assessment of the fine joint structures. Thirty infants were examined and the new device has proved useful in advanced hip dysplasia, therapy-resistant subluxation and luxation, and for operative therapy planning (reconstruction of the acetabular roof, redirectional osteotomies). Interpretation errors due to misprojection can be eliminated to a large extent since the holder allows standardized and reproducible positioning. (orig.)

Analysis of stress fractures associated with lameness in Thoroughbred flat racehorses training on different track surfaces undergoing nuclear scintigraphic examination.

Science.gov (United States)

MacKinnon, M C; Bonder, D; Boston, R C; Ross, M W

2015-05-01

There is limited information regarding the impact of training track surface on the occurrence of stress fractures. To evaluate the impact of training track surface on the proportion of long bone and pelvic stress fractures associated with lameness in Thoroughbred horses in flat race training undergoing nuclear scintigraphic examination. Retrospective study. Scintigraphic examinations of Thoroughbred flat racehorses were evaluated from 2 hospitals (hospital A [Toronto Equine Hospital], 2003-2009, and hospital B [George D. Widener Hospital for Large Animals, School of Veterinary Medicine, University of Pennsylvania], 1994-2006). Horses admitted to hospital A trained at a single track, at which the main training surface changed from dirt to synthetic on 27 August 2006. Two distinct populations existed at hospital B: horses that trained on dirt (numerous trainers) and those that trained on turf (single trainer). All scintigraphic images were evaluated by a blinded reviewer. Fisher's exact test and logistic regression were used when appropriate, and significance was set at Pfractures detected in scintigraphic examinations from horses training on a synthetic surface (31.7%) in comparison to scintigraphic examinations from horses training on a dirt surface (23.0%) at an earlier point in time (P = 0.03). There was a greater proportion of hindlimb/pelvic and tibial stress fractures diagnosed in horses from the synthetic surface-trained group than from the dirt-trained group at hospital A (Pfractures diagnosed, but other factors, such as training philosophy, appear to be important. Future prospective investigations to fully elucidate the relationship between training track surface and the proportion of stress fractures and other nonfatal musculoskeletal injuries are warranted. © 2014 EVJ Ltd.

Examining the free radical bonding mechanism of benzoquinone– and hydroquinone–methanol passivation of silicon surfaces

International Nuclear Information System (INIS)

Kotulak, Nicole A.; Chen, Meixi; Schreiber, Nikolas; Jones, Kevin; Opila, Robert L.

2015-01-01

Highlights: • Photons are required for high levels of c-Si passivation by both BQ/ME and HQ/ME solutions. • Protons are required for high levels of c-Si passivation by both BQ/ME and HQ/ME solutions. • The free radical QH· is the likely passivating species for c-Si surfaces from BQ/ME and HQ/ME solutions. - Abstract: The surface passivation of p-benzoquinone (BQ) and hydroquinone (HQ) when dissolved in methanol (ME) has been examined through effective lifetime testing of crystalline silicon (c-Si) wafers treated with the aforementioned solutions. Changes in the availability of both photons and protons in the solutions were demonstrated to affect the level of passivation achieved. The requirement of both excess protons and ambient light exposure to maintain high effective lifetimes supports the presence of a free radical species that drives the surface passivation. Surface analysis suggests a 1:1 ratio of HQ-like bonds to methoxy bonds on the c-Si surface after treatment with a BQ/ME solution.

Molecular Diagnosis of Trichomoniasis in Negative Samples Examined by Direct Smear and Culture

Directory of Open Access Journals (Sweden)

Z Valadkhani

2010-12-01

Full Text Available Background: Trichomoniasis is an extremely common sexually transmitted infection (STI world­wide and is associated with important public health problems, including amplification of HIV transmission. This disease is in forms of symptomatic and asymptomatic in women and may de­pend on host as well as parasite variables. Most of the studies reported from females are based on examination of vaginal secretions and urine samples by direct smear and culture in modified Dia­mond's media. The aim of this study was checking the samples, which were negative by direct smear and culture, with PCR technique.Methods: The urine samples and vaginal discharge of patients attending Gynecology Clinics of Ma­zandaran Province, Iran with different symptoms rechecked for Trichomonas vaginalis by PCR technique using primers targeting a conserved region of the beta-tubulin genes of the para­site. Data were analyzed by Epi Info software programResults: Out of 161 negative samples by direct smear and culture, seven samples (4.3% were posi­tive by PCR technique.Conclusion: Diagnosis of trichomoniasis by PCR is a sensitive and specific method that could play important role to help the physicians for properly treatment and control of infection.

Experimental demonstration of tunable directional excitation of surface plasmon polaritons with a subwavelength metallic double slit

Science.gov (United States)

Li, Xiaowei; Tan, Qiaofeng; Bai, Benfeng; Jin, Guofan

2011-06-01

We demonstrate experimentally the directional excitation of surface plasmon polaritons (SPPs) on a metal film by a subwavelength double slit under backside illumination, based on the interference of SPPs generated by the two slits. By varying the incident angle, the SPPs can be tunably directed into two opposite propagating directions with a predetermined splitting ratio. Under certain incident angle, unidirectional SPP excitation can be achieved. This compact directional SPP coupler is potentially useful for many on-chip applications. As an example, we show the integration of the double-slit couplers with SPP Bragg mirrors, which can effectively realize selective coupling of SPPs into different ports in an integrated plasmonic chip.

Direct measurement of Cu surface self-diffusion on a checked surface

International Nuclear Information System (INIS)

Cousty, Jacques; Peix, Roger; Perraillon, Bernard.

1976-01-01

A radiotracer technique ( 64 Cu) was developed to measure surface diffusion on copper surfaces of total impurity concentration not exceeding some 10 -3 monolayers. The apparatus used consists of a slow electron diffraction device, an Auger analysis spectrometer (CMA), an ion gun and an evaporation device assembled in an ultra-vacuum chamber holding a residual pressure below 10 -10 Torr. A sample handler enables the surface studied to be positioned in front of each of these instruments. During the diffusion treatment the chemical composition of the surface is checked intermittently, and afterwards the spread of the deposit is measured outside the ultravacuum chamber. Slices several microns thick are removed and dissolved separately in dishes containing HNO 3 . The activity is then measured with a flow counter [fr

Near-surface non-destructive examination of reactor steels: a state-of-the-art report

International Nuclear Information System (INIS)

Launay, J.P.

1985-06-01

A Working Group has been set up to deal with nondestructive testing reliability within the OECD/CSNI framework. One of its activities was to initiate consideration on near surface defect inspection, especially inner surfaces of reactors. The purpose of the survey was to clarify the three following points: present regulations of safety authorities and implementation of these regulations concerning manufacturing examinations and in-service inspection; results of R and D work already performed in this field; R and D work in progress and proposal for an expansion within the framework of the CSNI Special Working Group. This document summarizes information received from the following countries: USA, Spain, the Netherlands, France, United Kingdom, Belgium, Switzerland

A critical examination of the validity of simplified models for radiant heat transfer analysis.

Science.gov (United States)

Toor, J. S.; Viskanta, R.

1972-01-01

Examination of the directional effects of the simplified models by comparing the experimental data with the predictions based on simple and more detailed models for the radiation characteristics of surfaces. Analytical results indicate that the constant property diffuse and specular models do not yield the upper and lower bounds on local radiant heat flux. In general, the constant property specular analysis yields higher values of irradiation than the constant property diffuse analysis. A diffuse surface in the enclosure appears to destroy the effect of specularity of the other surfaces. Semigray and gray analyses predict the irradiation reasonably well provided that the directional properties and the specularity of the surfaces are taken into account. The uniform and nonuniform radiosity diffuse models are in satisfactory agreement with each other.

Comparison of a PCR-Based Method with Culture and Direct Examination for Diagnosis of Acanthamoeba keratitis

Directory of Open Access Journals (Sweden)

S Farnia

2009-05-01

Full Text Available "nBackground: The aim was to compare three different methods (direct examination, culture and PCR meth­ods for the diagnosis of Acanthamoeba keratitis (AK in corneal scrapes."nMethods: Twenty eight corneal scrapes and contact lenses were collected from keratitis patients and re­ferred to the De­partment of Medical Parasitology and Mycology, School of Public Health, Tehran Univer­sity of Medical Sci­ences. Corneal scrapes were divided in three parts for direct examination, culture on non-nutrient agar and PCR analysis. PCR analysis was also performed using a 18S rRNA gene primer pair (DF3 region. DF3 (Diagnostic frag­ment 3 is a region of the nuclear small subunit ribosomal RNA gene which is specific for detecting Acan­thamoeba strains."nResults:  Acanthamoeba was the causative agent of keratitis in 50% of the patients. Direct smear of all pre­pared corneal scrapes in AK patients was negative and culture was positive in only 14.3% of the isolates. PCR analysis was positive in 71.4% of AK patients. These three methods were negative in corneal scrapes of non-AK patients. The sensitivity and specificity of PCR technique for the detection of Acanthamoeba sp. were calculated as 71.4% and 100%, respectively."nConclusion: According to high sensitivity and specificity of PCR-based method, this study confirmed that PCR using 18S rRNA gene primers (DF3 region is more useful for detecting AK cases compare to culture and direct microscopy methods.

A surface-analytical examination of stringer particles in aluminum-lithium-copper alloys

Science.gov (United States)

Larson, L. A.; Avalos-Borja, M.; Pizzo, P. P.

1984-01-01

A surface analytical examination of powder metallurgy processed Al-Li-Cu alloys was conducted. The oxide stringer particles often found in these alloys are characterized. Particle characterization is important to more fully understand their impact on the stress corrosion and fracture properties of the alloy. The techniques used where SIMS (Secondary Ion Mass Spectroscopy) and SAM (Scanning Auger Microscopy). The results indicate that the oxide stringer particles contain both Al and LI with relatively high Li content and the Li compounds may be associated with the stringer particles, thereby locally depleting the adjacent matrix of Li solute.

Quantitative surface topography assessment of directly compressed and roller compacted tablet cores using photometric stereo image analysis

DEFF Research Database (Denmark)

Allesø, Morten; Carstensen, Jens Michael; Holm, Per

2016-01-01

Surface topography, in the context of surface smoothness/roughness, was investigated by the use of an image analysis technique, MultiRay™, related to photometric stereo, on different tablet batches manufactured either by direct compression or roller compaction. In the present study, oblique...... illumination of the tablet (darkfield) was considered and the area of cracks and pores in the surface was used as a measure of tablet surface topography; the higher a value, the rougher the surface. The investigations demonstrated a high precision of the proposed technique, which was able to rapidly (within...... milliseconds) and quantitatively measure the obtained surface topography of the produced tablets. Compaction history, in the form of applied roll force and tablet punch pressure, was also reflected in the measured smoothness of the tablet surfaces. Generally it was found that a higher degree of plastic...

Probing surface charge potentials of clay basal planes and edges by direct force measurements.

Science.gov (United States)

Zhao, Hongying; Bhattacharjee, Subir; Chow, Ross; Wallace, Dean; Masliyah, Jacob H; Xu, Zhenghe

2008-11-18

The dispersion and gelation of clay suspensions have major impact on a number of industries, such as ceramic and composite materials processing, paper making, cement production, and consumer product formulation. To fundamentally understand controlling mechanisms of clay dispersion and gelation, it is necessary to study anisotropic surface charge properties and colloidal interactions of clay particles. In this study, a colloidal probe technique was employed to study the interaction forces between a silica probe and clay basal plane/edge surfaces. A muscovite mica was used as a representative of 2:1 phyllosilicate clay minerals. The muscovite basal plane was prepared by cleavage, while the edge surface was obtained by a microtome cutting technique. Direct force measurements demonstrated the anisotropic surface charge properties of the basal plane and edge surface. For the basal plane, the long-range forces were monotonically repulsive within pH 6-10 and the measured forces were pH-independent, thereby confirming that clay basal planes have permanent surface charge from isomorphic substitution of lattice elements. The measured interaction forces were fitted well with the classical DLVO theory. The surface potentials of muscovite basal plane derived from the measured force profiles were in good agreement with those reported in the literature. In the case of edge surfaces, the measured forces were monotonically repulsive at pH 10, decreasing with pH, and changed to be attractive at pH 5.6, strongly suggesting that the charge on the clay edge surfaces is pH-dependent. The measured force profiles could not be reasonably fitted with the classical DLVO theory, even with very small surface potential values, unless the surface roughness was considered. The surface element integration (SEI) method was used to calculate the DLVO forces to account for the surface roughness. The surface potentials of the muscovite edges were derived by fitting the measured force profiles with the

Direct detection of near-surface faults by migration of back-scattered surface waves

KAUST Repository

Yu, Han; Guo, Bowen; Hanafy, Sherif; Lin, Fan-Chi; Schuster, Gerard T.

2014-01-01

We show that diffraction stack migration can be used to estimate the distribution of near-surface faults. The assumption is that near-surface faults generate detectable back-scattered surface waves from impinging surface waves. The processing steps

The calculation of the surface dose in examinations following cardiac catheterization

International Nuclear Information System (INIS)

Ewen, K.

1995-01-01

It is inevitable in examinations requiring patient exposure to high doses that the investigators and medical assistants receive high wholebody doses on account of fray radiation and, occasionally, also high partial body doses (hands) on account of the useful beam range. A number of different circumstances are adding up to create this extreme situation. In this connection, a mathematical method for the calculation of the surface dose (cutaneous dose rate) is described that is based on sets of parameters commonly used in diagnostic radiology: Set I of parameters: Tube voltage - current strength of tube - distance between focus and skin; - set II of parameters: Incidence dose rate of image intensifier - distance between focus and skin -distance between image intensifier and plane of ray incidence (skin). (orig./VHE) [de

Scanning Surface Potential Microscopy of Spore Adhesion on Surfaces

Energy Technology Data Exchange (ETDEWEB)

Lee, Ida [University of Tennessee, Knoxville (UTK); Chung, Eunhyea [Georgia Institute of Technology; Kweon, Hyojin [Georgia Institute of Technology; Yiacoumi, Sotira [Georgia Institute of Technology; Tsouris, Costas [ORNL

2012-01-01

The adhesion of spores of Bacillus anthracis - the cause of anthrax and a likely biological threat - to solid surfaces is an important consideration in cleanup after an accidental or deliberate release. However, because of safety concerns, directly studying B. anthracis spores with advanced instrumentation is problematic. As a first step, we are examining the electrostatic potential of Bacillus thuringiensis (Bt), which is a closely related species that is often used as a simulant to study B. anthracis. Scanning surface potential microscopy (SSPM), also known as Kelvin probe force microscopy (KPFM), was used to investigate the influence of relative humidity (RH) on the surface electrostatic potential of Bt that had adhered to silica, mica, or gold substrates. AFM/SSPM side-by-side images were obtained separately in air, at various values of RH, after an aqueous droplet with spores was applied on each surface and allowed to dry before measurements. In the SSPM images, a negative potential on the surface of the spores was observed compared with that of the substrates. The surface potential decreased as the humidity increased. Spores were unable to adhere to a surface with an extremely negative potential, such as mica.

Differential loggerhead by-catch and direct mortality due to surface longlines according to boat strata and gear type

Directory of Open Access Journals (Sweden)

Juan A. Camiñas

2006-12-01

Full Text Available Surface longline gears are used to fish different species, mainly albacore Thunnus alalunga (Bonnaterre, 1788, bluefin tuna Thunnus thynnus (Linnaeus, 1758, and swordfish Xiphias gladius Linnaeus, 1758, and are considered highly dangerous for threatened marine turtles. Loggerheads Caretta caretta (Linnaeus, 1758 can be incidentally captured by surface longlines. A number of captured individuals die during the fishing operation, which we consider direct mortality due to fishing. We analysed the relative loggerhead by-catch and direct mortality associated with each type of boat and gear from April to December during the period 1999-2004 in the Spanish surface longline fleet that fishes in the western Mediterranean Sea, an important fishing area for this fleet. We used different indices to compute the catch per unit effort (CPUE according to the number of hooks and to the number of fishing operations for each type of boat and gear. Both by-catch and direct mortality differed significantly according to the type of boat and gear. With respect to the number of hooks, boats longer than 12 m not using a roller and targeting bluefin tuna captured the highest number of loggerheads, whereas boats longer than 12 m with a roller that targeted swordfish caused the highest direct mortality. With respect to the number of fishing operations, boats longer than 12 m without a roller that targeted albacore captured the highest number of loggerheads; the highest direct mortality was caused by this type of boat and by boats longer than 12 m using a roller and targeting swordfish.

Direct detection of near-surface faults by migration of back-scattered surface waves

KAUST Repository

Yu, Han

2014-08-05

We show that diffraction stack migration can be used to estimate the distribution of near-surface faults. The assumption is that near-surface faults generate detectable back-scattered surface waves from impinging surface waves. The processing steps are to isolate the back-scattered surface waves, and then migrate them by diffraction migration using the surface wave velocity as the migration velocity. Instead of summing events along trial quasi-hyperbolas, surface wave migration sums events along trial quasi-linear trajectories that correspond to the moveout of back-scattered surface waves. A deconvolution filter derived from the data can be used to collapse a dispersive arrival into a non-dispersive event. Results with synthetic data and field records validate the feasibility of this method. Applying this method to USArray data or passively recorded exploration data might open new opportunities in mapping tectonic features over the extent of the array.

A versatile class of cell surface directional motors gives rise to gliding motility and sporulation in Myxococcus xanthus.

Directory of Open Access Journals (Sweden)

Morgane Wartel

2013-12-01

Full Text Available Eukaryotic cells utilize an arsenal of processive transport systems to deliver macromolecules to specific subcellular sites. In prokaryotes, such transport mechanisms have only been shown to mediate gliding motility, a form of microbial surface translocation. Here, we show that the motility function of the Myxococcus xanthus Agl-Glt machinery results from the recent specialization of a versatile class of bacterial transporters. Specifically, we demonstrate that the Agl motility motor is modular and dissociates from the rest of the gliding machinery (the Glt complex to bind the newly expressed Nfs complex, a close Glt paralogue, during sporulation. Following this association, the Agl system transports Nfs proteins directionally around the spore surface. Since the main spore coat polymer is secreted at discrete sites around the spore surface, its transport by Agl-Nfs ensures its distribution around the spore. Thus, the Agl-Glt/Nfs machineries may constitute a novel class of directional bacterial surface transporters that can be diversified to specific tasks depending on the cognate cargo and machinery-specific accessories.

Integrated modeling of groundwater-surface water interactions in a tile-drained agricultural field: The importance of directly measured flow route contributions

NARCIS (Netherlands)

Rozemeijer, J.C.; Velde, Y. van der; McLaren, R.G.; Geer, F.C. van; Broers, H.P.; Bierkens, M.F.P.

2010-01-01

Understanding the dynamics of groundwater-surface water interaction is needed to evaluate and simulate water and solute transport in catchments. However, direct measurements of the contributions of different flow routes from specific surfaces within a catchment toward the surface water are rarely

Applicability of surface-enhanced resonance Raman scattering for the direct discrimination of ballpoint pen inks

NARCIS (Netherlands)

Seifar, R.M.; Verheul, J.M.; Ariese, F.; Brinkman, U.A.T.; Gooijer, C.

2001-01-01

In situ surface-enhanced resonance Raman spectroscopy (SERRS) with excitation at 685 nm is suitable for the direct discrimination of blue and black ballpoint pen inks on paper. For black inks, shorter excitation wavelengths can also be used. For blue inks, SERRS at 514.5 and 457.9 nm does not

Surface Tension Directed Fluidic Self-Assembly of Semiconductor Chips across Length Scales and Material Boundaries

Directory of Open Access Journals (Sweden)

Shantonu Biswas

2016-03-01

Full Text Available This publication provides an overview and discusses some challenges of surface tension directed fluidic self-assembly of semiconductor chips which are transported in a liquid medium. The discussion is limited to surface tension directed self-assembly where the capture, alignment, and electrical connection process is driven by the surface free energy of molten solder bumps where the authors have made a contribution. The general context is to develop a massively parallel and scalable assembly process to overcome some of the limitations of current robotic pick and place and serial wire bonding concepts. The following parts will be discussed: (2 Single-step assembly of LED arrays containing a repetition of a single component type; (3 Multi-step assembly of more than one component type adding a sequence and geometrical shape confinement to the basic concept to build more complex structures; demonstrators contain (3.1 self-packaging surface mount devices, and (3.2 multi-chip assemblies with unique angular orientation. Subsequently, measures are discussed (4 to enable the assembly of microscopic chips (10 μm–1 mm; a different transport method is introduced; demonstrators include the assembly of photovoltaic modules containing microscopic silicon tiles. Finally, (5 the extension to enable large area assembly is presented; a first reel-to-reel assembly machine is realized; the machine is applied to the field of solid state lighting and the emerging field of stretchable electronics which requires the assembly and electrical connection of semiconductor devices over exceedingly large area substrates.

Near-surface hydrogen depletion of diamond-like carbon films produced by direct ion deposition

Science.gov (United States)

Markwitz, Andreas; Gupta, Prasanth; Mohr, Berit; Hübner, René; Leveneur, Jerome; Zondervan, Albert; Becker, Hans-Werner

2016-03-01

Amorphous atomically flat diamond-like carbon (DLC) coatings were produced by direct ion deposition using a system based on a Penning ion source, butane precursor gas and post acceleration. Hydrogen depth profiles of the DLC coatings were measured with the 15N R-NRA method using the resonant nuclear reaction 1H(15N, αγ)12C (Eres = 6.385 MeV). The films produced at 3.0-10.5 kV acceleration voltage show two main effects. First, compared to average elemental composition of the film, the near-surface region is hydrogen depleted. The increase of the hydrogen concentration by 3% from the near-surface region towards the bulk is attributed to a growth model which favours the formation of sp2 hybridised carbon rich films in the film formation zone. Secondly, the depth at which the maximum hydrogen concentration is measured increases with acceleration voltage and is proportional to the penetration depth of protons produced by the ion source from the precursor gas. The observed effects are explained by a deposition process that takes into account the contributions of ion species, hydrogen effusion and preferential displacement of atoms during direct ion deposition.

Large-Area Direct Laser-Shock Imprinting of a 3D Biomimic Hierarchical Metal Surface for Triboelectric Nanogenerators.

Science.gov (United States)

Jin, Shengyu; Wang, Yixiu; Motlag, Maithilee; Gao, Shengjie; Xu, Jin; Nian, Qiong; Wu, Wenzhuo; Cheng, Gary J

2018-03-01

Ongoing efforts in triboelectric nanogenerators (TENGs) focus on enhancing power generation, but obstacles concerning the economical and cost-effective production of TENGs continue to prevail. Micro-/nanostructure engineering of polymer surfaces has been dominantly utilized for boosting the contact triboelectrification, with deposited metal electrodes for collecting the scavenged energy. Nevertheless, this state-of-the-art approach is limited by the vague potential for producing 3D hierarchical surface structures with conformable coverage of high-quality metal. Laser-shock imprinting (LSI) is emerging as a potentially scalable approach for directly surface patterning of a wide range of metals with 3D nanoscale structures by design, benefiting from the ultrahigh-strain-rate forming process. Here, a TENG device is demonstrated with LSI-processed biomimetic hierarchically structured metal electrodes for efficient harvesting of water-drop energy in the environment. Mimicking and transferring hierarchical microstructures from natural templates, such as leaves, into these water-TENG devices is effective regarding repelling water drops from the device surface, since surface hydrophobicity from these biomicrostructures maximizes the TENG output. Among various leaves' microstructures, hierarchical microstructures from dried bamboo leaves are preferable regarding maximizing power output, which is attributed to their unique structures, containing both dense nanostructures and microscale features, compared with other types of leaves. Also, the triboelectric output is significantly improved by closely mimicking the hydrophobic nature of the leaves in the LSI-processed metal surface after functionalizing it with low-surface-energy self-assembled-monolayers. The approach opens doors to new manufacturable TENG technologies for economically feasible and ecologically friendly production of functional devices with directly patterned 3D biomimic metallic surfaces in energy

Examining direct and indirect pathways to health behaviour: the influence of cognitive and affective probability beliefs.

Science.gov (United States)

Janssen, Eva; van Osch, Liesbeth; de Vries, Hein; Lechner, Lilian

2013-01-01

This study aimed to extricate the influence of rational (e.g., 'I think …') and intuitive (e.g., 'I feel …') probability beliefs in the behavioural decision-making process regarding skin cancer prevention practices. Structural equation modelling was used in two longitudinal surveys (sun protection during winter sports [N = 491]; sun protection during summer [N = 277]) to examine direct and indirect behavioural effects of affective and cognitive likelihood (i.e. unmediated or mediated by intention), controlled for attitude, social influence and self-efficacy. Affective likelihood was directly related to sun protection in both studies, whereas no direct effects were found for cognitive likelihood. After accounting for past sun protective behaviour, affective likelihood was only directly related to sun protection in Study 1. No support was found for the indirect effects of affective and cognitive likelihood through intention. The findings underscore the importance of feelings of (cancer) risk in the decision-making process and should be acknowledged by health behaviour theories and risk communication practices. Suggestions for future research are discussed.

Preliminary Examination of Particles Recovered from the Surface of the Asteroid Itokawa by the Hayabusa Mission

Science.gov (United States)

Tsuchiyama, A.; Ebihara, M.; Kimura, M.; Kitajima, F.; Kotsugi, M.; Ito, S.; Nagao, K.; Nakamura, T.; Naraoka, H.; Noguchi, T.;

Establishing Antibacterial Multilayer Films on the Surface of Direct Metal Laser Sintered Titanium Primed with Phase-Transited Lysozyme

Science.gov (United States)

Guan, Binbin; Wang, Haorong; Xu, Ruiqing; Zheng, Guoying; Yang, Jie; Liu, Zihao; Cao, Man; Wu, Mingyao; Song, Jinhua; Li, Neng; Li, Ting; Cai, Qing; Yang, Xiaoping; Li, Yanqiu; Zhang, Xu

2016-11-01

Direct metal laser sintering is a technology that allows the fabrication of titanium (Ti) implants with a functional gradation of porosity and surface roughness according to three-dimensional (3D) computer data. The surface roughness of direct metal laser sintered titanium (DMLS-Ti) implants may provide abundant binding sites for bacteria. Bacterial colonization and subsequent biofilm formation can cause unsatisfactory cell adhesion and implant-related infections. To prevent such infections, a novel phase-transited lysozyme (PTL) was utilized as an initial functional layer to simply and effectively prime DMLS-Ti surfaces for subsequent coating with antibacterial multilayers. The purpose of the present study was to establish a surface with dual biological functionality. The minocycline-loaded polyelectrolyte multilayers of hyaluronic acid (HA) and chitosan (CS) formed via a layer-by-layer (LbL) self-assembly technique on PTL-functionalized DMLS-Ti were designed to inhibit pathogenic microbial infections while allowing the DMLS-Ti itself and the modified coatings to retain acceptable biocompatibility. The experimental results indicate that the DMLS-Ti and the hydrogel treated surfaces can inhibit early bacterial adhesion while completely preserving osteoblast functions. This design is expected to gain considerable interest in the medical field and to have good potential for applications in multifunctional DMLS-Ti implants.

Establishing Antibacterial Multilayer Films on the Surface of Direct Metal Laser Sintered Titanium Primed with Phase-Transited Lysozyme.

Science.gov (United States)

Guan, Binbin; Wang, Haorong; Xu, Ruiqing; Zheng, Guoying; Yang, Jie; Liu, Zihao; Cao, Man; Wu, Mingyao; Song, Jinhua; Li, Neng; Li, Ting; Cai, Qing; Yang, Xiaoping; Li, Yanqiu; Zhang, Xu

2016-11-08

Direct metal laser sintering is a technology that allows the fabrication of titanium (Ti) implants with a functional gradation of porosity and surface roughness according to three-dimensional (3D) computer data. The surface roughness of direct metal laser sintered titanium (DMLS-Ti) implants may provide abundant binding sites for bacteria. Bacterial colonization and subsequent biofilm formation can cause unsatisfactory cell adhesion and implant-related infections. To prevent such infections, a novel phase-transited lysozyme (PTL) was utilized as an initial functional layer to simply and effectively prime DMLS-Ti surfaces for subsequent coating with antibacterial multilayers. The purpose of the present study was to establish a surface with dual biological functionality. The minocycline-loaded polyelectrolyte multilayers of hyaluronic acid (HA) and chitosan (CS) formed via a layer-by-layer (LbL) self-assembly technique on PTL-functionalized DMLS-Ti were designed to inhibit pathogenic microbial infections while allowing the DMLS-Ti itself and the modified coatings to retain acceptable biocompatibility. The experimental results indicate that the DMLS-Ti and the hydrogel treated surfaces can inhibit early bacterial adhesion while completely preserving osteoblast functions. This design is expected to gain considerable interest in the medical field and to have good potential for applications in multifunctional DMLS-Ti implants.

A Comparison of Assessment Tools: Is Direct Observation an Improvement Over Objective Structured Clinical Examinations for Communications Skills Evaluation?

Science.gov (United States)

Goch, Abraham M; Karia, Raj; Taormina, David; Kalet, Adina; Zuckerman, Joseph; Egol, Kenneth A; Phillips, Donna

2018-04-01

Evaluation of resident physicians' communications skills is a challenging task and is increasingly accomplished with standardized examinations. There exists a need to identify the effective, efficient methods for assessment of communications skills. We compared objective structured clinical examination (OSCE) and direct observation as approaches for assessing resident communications skills. We conducted a retrospective cohort analysis of orthopaedic surgery resident physicians at a single tertiary care academic institution, using the Institute for Healthcare Communication "4 Es" model for effective communication. Data were collected between 2011 and 2015. A total of 28 residents, each with OSCE and complete direct observation assessment checklists, were included in the analysis. Residents were included if they had 1 OSCE assessment and 2 or more complete direct observation assessments. There were 28 of a possible 59 residents (47%) included. A total of 89% (25 of 28) of residents passed the communications skills OSCE; only 54% (15 of 28) of residents passed the direct observation communications assessment. There was a positive, moderate correlation between OSCE and direct observation scores overall ( r  = 0.415, P  = .028). There was no agreement between OSCE and direct observation in categorizing residents into passing and failing scores (κ = 0.205, P  = .16), after adjusting for chance agreement. Our results suggest that OSCE and direct observation tools provide different insights into resident communications skills (simulation of rare and challenging situations versus real-life daily encounters), and may provide useful perspectives on resident communications skills in different contexts.

The radial hardness-profile and the microstructure of railroad car axle materials treated by surface rolling, determined by novel examination methods

International Nuclear Information System (INIS)

Berecz, Tibor; Balogh, Levente; Mészáros, István; Steinbach, Ágoston

2014-01-01

Surface rolling is a cold-working technique used for hardening the surface of steel and ductile cast iron components. This process increases the surface hardness and improves the fatigue properties of components, so it is commonly used to treat railroad car wheel axles. The present paper examines the influence of this surface strengthening technique on the microstructure of the railroad car wheel axle material by hardness tests, optical microscopy (OM), and other novel examination methods, such as scanning electron microscopy (SEM), X-ray line profile analysis (XLPA), non-destructive magnetic evaluation (NDE) and automated electron backscatter diffraction (EBSD). The results show that surface rolling causes an increase in hardness down to a depth of ∼10 mm. It is also shown, that the increase in hardness is not due to grain refinement or change in grain morphology; thus it is likely to be caused by an increase in dislocation density

The radial hardness-profile and the microstructure of railroad car axle materials treated by surface rolling, determined by novel examination methods

Energy Technology Data Exchange (ETDEWEB)

Berecz, Tibor, E-mail: berecz@eik.bme.hu [Department of Materials Science and Engineering, Budapest University of Technology and Economics, 1111 Budapest, Bertalan Lajos utca 7 (Hungary); Balogh, Levente, E-mail: levente@metal.elte.hu [Department of Materials Physics, Eötvös Loránd University, 1117 Budapest, Pázmány Péter sétány 1/a (Hungary); Mészáros, István, E-mail: meszaros@eik.bme.hu [Department of Materials Science and Engineering, Budapest University of Technology and Economics, 1111 Budapest, Bertalan Lajos utca 7 (Hungary); Steinbach, Ágoston, E-mail: sa984@hszk.bme.hu [Department of Materials Science and Engineering, Budapest University of Technology and Economics, 1111 Budapest, Bertalan Lajos utca 7 (Hungary)

2014-01-13

Surface rolling is a cold-working technique used for hardening the surface of steel and ductile cast iron components. This process increases the surface hardness and improves the fatigue properties of components, so it is commonly used to treat railroad car wheel axles. The present paper examines the influence of this surface strengthening technique on the microstructure of the railroad car wheel axle material by hardness tests, optical microscopy (OM), and other novel examination methods, such as scanning electron microscopy (SEM), X-ray line profile analysis (XLPA), non-destructive magnetic evaluation (NDE) and automated electron backscatter diffraction (EBSD). The results show that surface rolling causes an increase in hardness down to a depth of ∼10 mm. It is also shown, that the increase in hardness is not due to grain refinement or change in grain morphology; thus it is likely to be caused by an increase in dislocation density.

Origin of bending in uncoated microcantilever - Surface topography?

International Nuclear Information System (INIS)

Lakshmoji, K.; Prabakar, K.; Tripura Sundari, S.; Jayapandian, J.; Tyagi, A. K.; Sundar, C. S.

2014-01-01

We provide direct experimental evidence to show that difference in surface topography on opposite sides of an uncoated microcantilever induces bending, upon exposure to water molecules. Examination on opposite sides of the microcantilever by atomic force microscopy reveals the presence of localized surface features on one side, which renders the induced stress non-uniform. Further, the root mean square inclination angle characterizing the surface topography shows a difference of 73° between the opposite sides. The absence of deflection in another uncoated microcantilever having similar surface topography confirms that in former microcantilever bending is indeed induced by differences in surface topography

An Artificial Turf-Based Surrogate Surface Collector for the Direct Measurement of Atmospheric Mercury Dry Deposition

Directory of Open Access Journals (Sweden)

Naima L. Hall

2017-02-01

Full Text Available This paper describes the development of a new artificial turf surrogate surface (ATSS sampler for use in the measurement of mercury (Hg dry deposition. In contrast to many existing surrogate surface designs, the ATSS utilizes a three-dimensional deposition surface that may more closely mimic the physical structure of many natural surfaces than traditional flat surrogate surface designs (water, filter, greased Mylar film. The ATSS has been designed to overcome several complicating factors that can impact the integrity of samples with other direct measurement approaches by providing a passive system which can be deployed for both short and extended periods of time (days to weeks, and is not contaminated by precipitation and/or invalidated by strong winds. Performance characteristics including collocated precision, in-field procedural and laboratory blanks were evaluated. The results of these performance evaluations included a mean collocated precision of 9%, low blanks (0.8 ng, high extraction efficiency (97%–103%, and a quantitative matrix spike recovery (100%.

Research on the effect of coverage rate on the surface quality in laser direct writing process

Science.gov (United States)

Pan, Xuetao; Tu, Dawei

2017-07-01

Direct writing technique is usually used in femtosecond laser two-photon micromachining. The size of the scanning step is an important factor affecting the surface quality and machining efficiency of micro devices. According to the mechanism of two-photon polymerization, combining the distribution function of light intensity and the free radical concentration theory, we establish the mathematical model of coverage of solidification unit, then analyze the effect of coverage on the machining quality and efficiency. Using the principle of exposure equivalence, we also obtained the analytic expressions of the relationship among the surface quality characteristic parameters of microdevices and the scanning step, and carried out the numerical simulation and experiment. The results show that the scanning step has little influence on the surface quality of the line when it is much smaller than the size of the solidification unit. However, with increasing scanning step, the smoothness of line surface is reduced rapidly, and the surface quality becomes much worse.

Environmental bias and elastic curves on surfaces

International Nuclear Information System (INIS)

Guven, Jemal; María Valencia, Dulce; Vázquez-Montejo, Pablo

2014-01-01

The behavior of an elastic curve bound to a surface will reflect the geometry of its environment. This may occur in an obvious way: the curve may deform freely along directions tangent to the surface, but not along the surface normal. However, even if the energy itself is symmetric in the curve's geodesic and normal curvatures, which control these modes, very distinct roles are played by the two. If the elastic curve binds preferentially on one side, or is itself assembled on the surface, not only would one expect the bending moduli associated with the two modes to differ, binding along specific directions, reflected in spontaneous values of these curvatures, may be favored. The shape equations describing the equilibrium states of a surface curve described by an elastic energy accommodating environmental factors will be identified by adapting the method of Lagrange multipliers to the Darboux frame associated with the curve. The forces transmitted to the surface along the surface normal will be determined. Features associated with a number of different energies, both of physical relevance and of mathematical interest, are described. The conservation laws associated with trajectories on surface geometries exhibiting continuous symmetries are also examined. (paper)

Polar Direct Drive-Ignition at 1 MJ

International Nuclear Information System (INIS)

Skupsky, S.; Craxton, R.S.; Marshall, F.J.; Betti, R.; Collins, T.J.B.; Epstein, R.; Goncharov, V.N.; Igumenshchev, I.V.; Marozas, J.A.; McKenty, P.W.; Radha, P.B.; Kilkenny, J.D.; Meyerhofer, D.D.; Sangster, T.C.; McCrory, R.L.

2006-01-01

Target designs to achieve direct-drive ignition on the NIF using the x-ray-drive beam configuration are examined. This approach, known as polar direct drive (PDD), achieves the required irradiation uniformity by repointing some of the beams toward the target equator, and by increasing the laser intensity at the equator to compensate for the reduced laser coupling from oblique irradiation. Techniques to increase the equatorial intensity can include using phase plates that produce elliptical spot shapes, increasing the power in beams directed toward the equator, and using a ring offset from the equator to redirect rays toward the target normal. The requirements for beam pointing, power balance, single-beam smoothing, and inner-ice-surface roughness are examined. Designs with an incident laser energy of 1.0 MJ are presented. The simulations use the 2-D hydrocode DRACO with 3-D ray trace to model the laser irradiation and Monte Carlo alpha particle transport to model the thermonuclear burn

Direct surface analysis of pesticides on soil, leaves, grass, and stainless steel by static secondary ion mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Ingram, J.C.; Groenewold, G.S.; Appelhans, A.D.; Delmore, J.E.; Olson, J.E.; Miller, D.L. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1997-02-01

Direct surface analyses by static secondary ion mass spectrometry (SIMS) were performed for the following pesticides adsorbed on dandelion leaves, grass, soil, and stainless steel samples: alachlor, atrazine, captan, carbofuran, chlorpyrifos, chlorosulfuron, chlorthal-dimethyl, cypermethrin, 2,4-D, diuron, glyphosate, malathion, methomyl, methyl arsonic acid, mocap, norflurazon, oxyfluorfen, paraquat, temik, and trifluralin. The purpose of this study was to evaluate static SIMS as a tool for pesticide analysis, principally for use in screening samples for pesticides. The advantage of direct surface analysis compared with conventional pesticide analysis methods is the elimination of sample pretreatment including extraction, which streamlines the analysis substantially; total analysis time for SIMS analysis was ca. 10 min/sample. Detection of 16 of the 20 pesticides on all four substrates was achieved. Of the remaining four pesticides, only one (trifluralin) was not detected on any of the samples. The minimum detectable quantity was determined for paraquat on soil in order to evaluate the efficacy of using SIMS as a screening tool. Paraquat was detected at 3 pg/mm{sup 2} (c.a. 0.005 monolayers). The results of these studies suggest that SIMS is capable of direct surface detection of a range of pesticides, with low volatility, polar pesticides being the most easily detected. 25 refs., 2 figs., 2 tabs.

Academic Self-Concept and Learning Strategies: Direction of Effect on Student Academic Achievement

Science.gov (United States)

McInerney, Dennis M.; Cheng, Rebecca Wing-yi; Mok, Magdalena Mo Ching; Lam, Amy Kwok Hap

2012-01-01

This study examined the prediction of academic self-concept (English and Mathematics) and learning strategies (deep and surface), and their direction of effect, on academic achievement (English and Mathematics) of 8,354 students from 16 secondary schools in Hong Kong. Two competing models were tested to ascertain the direction of effect: Model A…

Electrografted diazonium salt layers for antifouling on the surface of surface plasmon resonance biosensors.

Science.gov (United States)

Zou, Qiongjing; Kegel, Laurel L; Booksh, Karl S

2015-02-17

Electrografted diazonium salt layers on the surface of surface plasmon resonance (SPR) sensors present potential for a significant improvement in antifouling coatings. A pulsed potential deposition profile was used in order to circumvent mass-transport limitations for layer deposition rate. The influence of number of pulses with respect to antifouling efficacy was evaluated by nonspecific adsorption surface coverage of crude bovine serum proteins. Instead of using empirical and rough estimated values, the penetration depth and sensitivity of the SPR instrument were experimentally determined for the calculation of nonspecific adsorption surface coverage. This provides a method to better examine antifouling surface coatings and compare crossing different coatings and experimental systems. Direct comparison of antifouling performance of different diazonium salts was facilitated by a tripad SPR sensor design. The electrografted 4-phenylalanine diazonium chloride (4-APhe) layers with zwitterionic characteristic demonstrate ultralow fouling.

Stereo imaging and cytocompatibility of a model dental implant surface formed by direct laser fabrication.

Science.gov (United States)

Mangano, Carlo; Raspanti, Mario; Traini, Tonino; Piattelli, Adriano; Sammons, Rachel

2009-03-01

Direct laser fabrication (DLF) allows solids with complex geometry to be produced by sintering metal powder particles in a focused laser beam. In this study, 10 Ti6Al4V alloy model dental root implants were obtained by DLF, and surface characterization was carried out using stereo scanning electron microscopy to produce 3D reconstructions. The surfaces were extremely irregular, with approximately 100 microm deep, narrow intercommunicating crevices, shallow depressions and deep, rounded pits of widely variable shape and size, showing ample scope for interlocking with the host bone. Roughness parameters were as follows: R(t), 360.8 microm; R(z), 358.4 microm; R(a), 67.4 microm; and R(q), 78.0 microm. Disc specimens produced by DLF with an identically prepared surface were used for biocompatibility studies with rat calvarial osteoblasts: After 9 days, cells had attached and spread on the DLF surface, spanning across the crevices, and voids. Cell density was similar to that on a commercial rough microtextured surface but lower than on commercial smooth machined and smooth-textured grit-blasted, acid-etched surfaces. Human fibrin clot extension on the DLF surface was slightly improved by inorganic acid etching to increase the microroughness. With further refinements, DLF could be an economical means of manufacturing implants from titanium alloys. (c) 2008 Wiley Periodicals, Inc.

Topographical cues of direct metal laser sintering titanium surfaces facilitate osteogenic differentiation of bone marrow mesenchymal stem cells through epigenetic regulation.

Science.gov (United States)

Zheng, Guoying; Guan, Binbin; Hu, Penghui; Qi, Xingying; Wang, Pingting; Kong, Yu; Liu, Zihao; Gao, Ping; Li, Rui; Zhang, Xu; Wu, Xudong; Sui, Lei

2018-04-27

To investigate the role of hierarchical micro/nanoscale topography of direct metal laser sintering (DMLS) titanium surfaces in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), as well as the possible underlying epigenetic mechanism. Three groups of titanium specimens were prepared, including DMLS group, sandblasted, large-grit, acid-etched (SLA) group and smooth titanium (Ti) group. BMSCs were cultured on discs followed by surface characterization. Cell adhesion and proliferation were examined by SEM and CCK-8 assay, while osteogenic-related gene expression was detected by real-time RT-PCR. Immunofluorescence, western blotting and in vivo study were also performed to evaluate the potential for osteogenic induction of materials. In addition, to investigate the underlying epigenetic mechanisms, immunofluorescence and western blotting were performed to evaluate the global level of H3K4me3 during osteogenesis. The H3K4me3 and H3K27me3 levels at the promoter area of the osteogenic gene Runx2 were detected by ChIP assay. The DMLS surface exhibits greater protein adsorption ability and shows better cell adhesion performance than SLA and Ti surfaces. Moreover, both in vitro and in vivo studies demonstrated that the DMLS surface is more favourable for the osteogenic differentiation of BMSCs than SLA and Ti surfaces. Accordingly, osteogenesis-associated gene expression in BMSCs is efficiently induced by a rapid H3K27 demethylation and increase in H3K4me3 levels at gene promoters upon osteogenic differentiation on DMLS titanium surface. Topographical cues of DMLS surfaces have greater potential for the induction of osteogenic differentiation of BMSCs than SLA and Ti surfaces both in vitro and in vivo. A potential epigenetic mechanism is that the appropriate topography allows rapid H3K27 demethylation and an increased H3K4me3 level at the promoter region of osteogenesis-associated genes during the osteogenic differentiation of BMSCs. © 2018 John Wiley

Near-surface hydrogen depletion of diamond-like carbon films produced by direct ion deposition

Energy Technology Data Exchange (ETDEWEB)

Markwitz, Andreas, E-mail: A.Markwitz@gns.cri.nz [GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Gupta, Prasanth [GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Mohr, Berit [GNS Science, Lower Hutt (New Zealand); Hübner, René [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Leveneur, Jerome; Zondervan, Albert [GNS Science, Lower Hutt (New Zealand); Becker, Hans-Werner [RUBION, Ruhr-University Bochum (Germany)

2016-03-15

Amorphous atomically flat diamond-like carbon (DLC) coatings were produced by direct ion deposition using a system based on a Penning ion source, butane precursor gas and post acceleration. Hydrogen depth profiles of the DLC coatings were measured with the 15N R-NRA method using the resonant nuclear reaction {sup 1}H({sup 15}N, αγ){sup 12}C (E{sub res} = 6.385 MeV). The films produced at 3.0–10.5 kV acceleration voltage show two main effects. First, compared to average elemental composition of the film, the near-surface region is hydrogen depleted. The increase of the hydrogen concentration by 3% from the near-surface region towards the bulk is attributed to a growth model which favours the formation of sp{sup 2} hybridised carbon rich films in the film formation zone. Secondly, the depth at which the maximum hydrogen concentration is measured increases with acceleration voltage and is proportional to the penetration depth of protons produced by the ion source from the precursor gas. The observed effects are explained by a deposition process that takes into account the contributions of ion species, hydrogen effusion and preferential displacement of atoms during direct ion deposition.

Examination of Surface Deposits on Oldbury Reactor Core Graphite to Determine the Concentration and Distribution of 14C.

Directory of Open Access Journals (Sweden)

Liam Payne

Full Text Available Pile Grade A graphite was used as a moderator and reflector material in the first generation of UK Magnox nuclear power reactors. As all of these reactors are now shut down there is a need to examine the concentration and distribution of long lived radioisotopes, such as 14C, to aid in understanding their behaviour in a geological disposal facility. A selection of irradiated graphite samples from Oldbury reactor one were examined where it was observed that Raman spectroscopy can distinguish between underlying graphite and a surface deposit found on exposed channel wall surfaces. The concentration of 14C in this deposit was examined by sequentially oxidising the graphite samples in air at low temperatures (450°C and 600°C to remove the deposit and then the underlying graphite. The gases produced were captured in a series of bubbler solutions that were analysed using liquid scintillation counting. It was observed that the surface deposit was relatively enriched with 14C, with samples originating lower in the reactor exhibiting a higher concentration of 14C. Oxidation at 600°C showed that the remaining graphite material consisted of two fractions of 14C, a surface associated fraction and a graphite lattice associated fraction. The results presented correlate well with previous studies on irradiated graphite that suggest there are up to three fractions of 14C; a readily releasable fraction (corresponding to that removed by oxidation at 450°C in this study, a slowly releasable fraction (removed early at 600°C in this study, and an unreleasable fraction (removed later at 600°C in this study.

Understanding the Asian summer monsoon response to greenhouse warming: the relative roles of direct radiative forcing and sea surface temperature change

Science.gov (United States)

Li, Xiaoqiong; Ting, Mingfang

2017-10-01

Future hydroclimate projections from state-of-the-art climate models show large uncertainty and model spread, particularly in the tropics and over the monsoon regions. The precipitation and circulation responses to rising greenhouse gases involve a fast component associated with direct radiative forcing and a slow component associated with sea surface temperature (SST) warming; the relative importance of the two may contribute to model discrepancies. In this study, regional hydroclimate responses to greenhouse warming are assessed using output from coupled general circulation models in the Coupled Model Intercomparison Project-Phase 5 (CMIP5) and idealized atmospheric general circulation model experiments from the Atmosphere Model Intercomparison Project. The thermodynamic and dynamic mechanisms causing the rainfall changes are examined using moisture budget analysis. Results show that direct radiative forcing and SST change exert significantly different responses both over land and ocean. For most part of the Asian monsoon region, the summertime rainfall changes are dominated by the direct CO2 radiative effect through enhanced monsoon circulation. The response to SST warming shows a larger model spread compared to direct radiative forcing, possibly due to the cancellation between the thermodynamical and dynamical components. While the thermodynamical response of the Asian monsoon is robust across the models, there is a lack of consensus for the dynamical response among the models and weak multi-model mean responses in the CMIP5 ensemble, which may be related to the multiple physical processes evolving on different time scales.

Surface acoustic wave propagation in graphene film

International Nuclear Information System (INIS)

Roshchupkin, Dmitry; Plotitcyna, Olga; Matveev, Viktor; Kononenko, Oleg; Emelin, Evgenii; Irzhak, Dmitry; Ortega, Luc; Zizak, Ivo; Erko, Alexei; Tynyshtykbayev, Kurbangali; Insepov, Zinetula

2015-01-01

Surface acoustic wave (SAW) propagation in a graphene film on the surface of piezoelectric crystals was studied at the BESSY II synchrotron radiation source. Talbot effect enabled the visualization of the SAW propagation on the crystal surface with the graphene film in a real time mode, and high-resolution x-ray diffraction permitted the determination of the SAW amplitude in the graphene/piezoelectric crystal system. The influence of the SAW on the electrical properties of the graphene film was examined. It was shown that the changing of the SAW amplitude enables controlling the magnitude and direction of current in graphene film on the surface of piezoelectric crystals

Examination of the surface coatings removed from K-East Basin fuel elements

International Nuclear Information System (INIS)

Abrefah, J.; Marschman, S.C.; Jenson, E.D.

1998-05-01

This report provides the results of studies conducted on coatings discovered on the surfaces of some N-Reactor spent nuclear fuel (SNF) elements stored at the Hanford K-East Basin. These elements had been removed from the canisters and visually examined in-basin during FY 1996 as part of a series of characterization tests. The characterization tests are being performed to support the Integrated Process Strategy developed to package, dry, transport, and store the SNF in an interim storage facility on the Hanford site. Samples of coating materials were removed from K-East canister elements 2350E and 2540E, which had been sent, along with nine other elements, to the Postirradiation Testing Laboratory (327 Building) for further characterization following the in-basin examinations. These coating samples were evaluated by Pacific Northwest National Laboratory using various analytical methods. This report is part of the overall studies to determine the drying behavior of corrosion products associated with the K-Basin fuel elements. Altogether, five samples of coating materials were analyzed. These analyses suggest that hydration of the coating materials could be an additional source of moisture in the Multi-Canister Overpacks being used to contain the fuel for storage

Examination of the surface coating removed from K-East Basin fuel elements

Energy Technology Data Exchange (ETDEWEB)

Abrefah, J.; Marschman, S.C.; Jenson, E.D.

1998-05-01

This report provides the results of studies conducted on coatings discovered on the surfaces of some N-Reactor spent nuclear fuel (SNF) elements stored at the Hanford K-East Basin. These elements had been removed from the canisters and visually examined in-basin during FY 1996 as part of a series of characterization tests. The characterization tests are being performed to support the Integrated Process Strategy developed to package, dry, transport, and store the SNF in an interim storage facility on the Hanford site. Samples of coating materials were removed from K-East canister elements 2350E and 2540E, which had been sent, along with nine other elements, to the Postirradiation Testing Laboratory (327 Building) for further characterization following the in-basin examinations. These coating samples were evaluated by Pacific Northwest National Laboratory using various analytical methods. This report is part of the overall studies to determine the drying behavior of corrosion products associated with the K-Basin fuel elements. Altogether, five samples of coating materials were analyzed. These analyses suggest that hydration of the coating materials could be an additional source of moisture in the Multi-Canister Overpacks being used to contain the fuel for storage.

Direct numerical simulation of turbulent flows over superhydrophobic surfaces with gas pockets using linearized boundary conditions

Science.gov (United States)

Seo, Jongmin; Bose, Sanjeeb; Garcia-Mayoral, Ricardo; Mani, Ali

2012-11-01

Superhydrophobic surfaces are shown to be effective for surface drag reduction under laminar regime by both experiments and simulations (see for example, Ou and Rothstein, Phys. Fluids 17:103606, 2005). However, such drag reduction for fully developed turbulent flow maintaining the Cassie-Baxter state remains an open problem due to high shear rates and flow unsteadiness of turbulent boundary layer. Our work aims to develop an understanding of mechanisms leading to interface breaking and loss of gas pockets due to interactions with turbulent boundary layers. We take advantage of direct numerical simulation of turbulence with slip and no-slip patterned boundary conditions mimicking the superhydrophobic surface. In addition, we capture the dynamics of gas-water interface, by deriving a proper linearized boundary condition taking into account the surface tension of the interface and kinematic matching of interface deformation and normal velocity conditions on the wall. We will show results from our simulations predicting the dynamical behavior of gas pocket interfaces over a wide range of dimensionless surface tensions. Supported by the Office of Naval Research and the Kwanjeong Educational Scholarship Foundation.

Design of LD in-band direct-pumping side surface polished micro-rod Nd:YVO4 laser

International Nuclear Information System (INIS)

Zhang Wen-Qi; Wang Fei; Liu Qiang; Gong Ma-Li

2016-01-01

To diminish the thermal load, two ways, that is, in-band direct pumping and micro-rod crystal, could be adopted at the same time. The efficiency of LD in-band direct-pumping side surface polished micro-rod Nd:YVO 4 laser is numerically analyzed. By optimizing parameters such as crystal length, laser mode radius, pump beam radius, doping concentration and crystal cross-section size, the overall efficiency can reach over 50%. It is found that with micro-rod crystal implemented in the laser oscillator, high overall efficiency LD in-band direct-pumping Nd:YVO 4 laser could be realized. High efficiency combined with low thermal load makes this laser an outstanding scheme for building high-power Nd:YVO 4 lasers. (paper)

Highly directive Fabry-Perot leaky-wave nanoantennas based on optical partially reflective surfaces

Energy Technology Data Exchange (ETDEWEB)

Lorente-Crespo, M.; Mateo-Segura, C., E-mail: C.Mateo-Segura@hw.ac.uk [Institute of Sensors, Signals and Systems, Heriot-Watt University, EH14 4AS Edinburgh (United Kingdom)

2015-05-04

Nanoantennas enhance the conversion between highly localized electromagnetic fields and far-field radiation. Here, we investigate the response of a nano-patch partially reflective surface backed with a silver mirror to an optical source embedded at the centre of the structure. Using full wave simulations, we demonstrate a two orders of magnitude increased directivity compared to the isotropic radiator, 50% power confinement to a 13.8° width beam and a ±16 nm bandwidth. Our antenna does not rely on plasmonic phenomena thus reducing non-radiative losses and conserving source coherence.

Quantitative surface topography assessment of directly compressed and roller compacted tablet cores using photometric stereo image analysis.

Science.gov (United States)

Allesø, Morten; Holm, Per; Carstensen, Jens Michael; Holm, René

2016-05-25

Surface topography, in the context of surface smoothness/roughness, was investigated by the use of an image analysis technique, MultiRay™, related to photometric stereo, on different tablet batches manufactured either by direct compression or roller compaction. In the present study, oblique illumination of the tablet (darkfield) was considered and the area of cracks and pores in the surface was used as a measure of tablet surface topography; the higher a value, the rougher the surface. The investigations demonstrated a high precision of the proposed technique, which was able to rapidly (within milliseconds) and quantitatively measure the obtained surface topography of the produced tablets. Compaction history, in the form of applied roll force and tablet punch pressure, was also reflected in the measured smoothness of the tablet surfaces. Generally it was found that a higher degree of plastic deformation of the microcrystalline cellulose resulted in a smoother tablet surface. This altogether demonstrated that the technique provides the pharmaceutical developer with a reliable, quantitative response parameter for visual appearance of solid dosage forms, which may be used for process and ultimately product optimization. Copyright © 2015 Elsevier B.V. All rights reserved.

Direct impression on agar surface as a diagnostic sampling procedure for candida balanitis.

Science.gov (United States)

Lisboa, Carmen; Santos, António; Azevedo, Filomena; Pina-Vaz, Cidália; Rodrigues, Acácio Gonçalves

2010-02-01

The diagnosis of candida balanitis should be based upon both clinical and mycological data. The procedure of material collection is a critical issue to confirm or rule out the clinical diagnosis of candida balanitis. To compare direct impression of the glans on the agar surface of solid culture media with the collection of genital exudates with cotton swab for the diagnosis of candida balanitis. A prospective cross-sectional study was carried out during a 36-month period. Sexually transmitted disease clinic attendees with balanitis and asymptomatic men were included. Specimens for yeast culture were collected from the glans penis and inner preputial layer using the direct impression on CHROMagar candida medium and by swabbing with a sterile cotton swab. Among 478 men enrolled, 189 had balanitis. The prevalence of candida balanitis was 17.8% (85/478) confirmed after culture by direct impression; the swab method detected only 54/85 (63.5%) of these men. Of the 289 asymptomatic men, 36 (12.5%) yielded Candida spp; the swab method detected only 38.9% of these men. The risk of having candida balanitis is 8.9 (IC 95% 2.48 to 32.04) whenever the number of candida colonies recovered by direct impression was greater than 10. Direct impression on CHROMagar candida medium resulted in the highest Candida spp recovery rate. More than 10 colonies yielded by impression culture were statistically associated with candida balanitis. This method shows the ideal profile for sampling the male genital area for yeasts and should be included in the management of balanitis.

ZnO nanostructures directly grown on paper and bacterial cellulose substrates without any surface modification layer.

Science.gov (United States)

Costa, Saionara V; Gonçalves, Agnaldo S; Zaguete, Maria A; Mazon, Talita; Nogueira, Ana F

2013-09-21

In this report, hierarchical ZnO nano- and microstructures were directly grown for the first time on a bacterial cellulose substrate and on two additional different papers by hydrothermal synthesis without any surface modification layer. Compactness and smoothness of the substrates are two important parameters that allow the growth of oriented structures.

Thermal radiation characteristics and direct evidence of tungsten cooling on the way to nanostructure formation on its surface

Energy Technology Data Exchange (ETDEWEB)

Takamura, S., E-mail: takamura@aitech.ac.jp [Faculty of Engineering, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Miyamoto, T. [Faculty of Engineering, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Ohno, N. [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

2013-07-15

The physical properties of tungsten with nanostructure on its surface are investigated focusing on the thermal radiation and cooling characteristics. First, direct evidence of substantial W surface cooling has been clearly shown with use of a very thin thermocouple inserted into W target, which solves an uncertainty associated with a radiation thermometer. Second, the above measurements of W surface temperature make it possible to estimate quantitatively the total emissivity from which we may evaluate the radiative power through the Stefan–Boltzmann equation, which is very important for mitigation evaluation of a serious plasma heat load to the plasma-facing component.

Thermal radiation characteristics and direct evidence of tungsten cooling on the way to nanostructure formation on its surface

International Nuclear Information System (INIS)

Takamura, S.; Miyamoto, T.; Ohno, N.

2013-01-01

The physical properties of tungsten with nanostructure on its surface are investigated focusing on the thermal radiation and cooling characteristics. First, direct evidence of substantial W surface cooling has been clearly shown with use of a very thin thermocouple inserted into W target, which solves an uncertainty associated with a radiation thermometer. Second, the above measurements of W surface temperature make it possible to estimate quantitatively the total emissivity from which we may evaluate the radiative power through the Stefan–Boltzmann equation, which is very important for mitigation evaluation of a serious plasma heat load to the plasma-facing component

Direct Covalent Grafting of Phytate to Titanium Surfaces through Ti-O-P Bonding Shows Bone Stimulating Surface Properties and Decreased Bacterial Adhesion.

Science.gov (United States)

Córdoba, Alba; Hierro-Oliva, Margarita; Pacha-Olivenza, Miguel Ángel; Fernández-Calderón, María Coronada; Perelló, Joan; Isern, Bernat; González-Martín, María Luisa; Monjo, Marta; Ramis, Joana M

2016-05-11

Myo-inositol hexaphosphate, also called phytic acid or phytate (IP6), is a natural molecule abundant in vegetable seeds and legumes. Among other functions, IP6 inhibits bone resorption. It is adsorbed on the surface of hydroxyapatite, inhibiting its dissolution and decreasing the progressive loss of bone mass. We present here a method to directly functionalize Ti surfaces covalently with IP6, without using a cross-linker molecule, through the reaction of the phosphate groups of IP6 with the TiO2 layer of Ti substrates. The grafting reaction consisted of an immersion in an IP6 solution to allow the physisorption of the molecules onto the substrate, followed by a heating step to obtain its chemisorption, in an adaptation of the T-Bag method. The reaction was highly dependent on the IP6 solution pH, only achieving a covalent Ti-O-P bond at pH 0. We evaluated two acidic pretreatments of the Ti surface, to increase its hydroxylic content, HNO3 30% and HF 0.2%. The structure of the coated surfaces was characterized by X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and ellipsometry. The stability of the IP6 coating after three months of storage and after sterilization with γ-irradiation was also determined. Then, we evaluated the biological effect of Ti-IP6 surfaces in vitro on MC3T3-E1 osteoblastic cells, showing an osteogenic effect. Finally, the effect of the surfaces on the adhesion and biofilm viability of oral microorganisms S. mutans and S. sanguinis was also studied, and we found that Ti-IP6 surfaces decreased the adhesion of S. sanguinis. A surface that actively improves osseointegration while decreasing the bacterial adhesion could be suitable for use in bone implants.

Techniques in gas-phase thermolyses - Part 7. Direct surface participation in gas-phase Curie-point pyrolysis: The pyrolysis of phenyl azide

DEFF Research Database (Denmark)

Egsgaard, Helge; Carlsen, Lars

1986-01-01

The possible direct participation of the hot reactor surface in the formation of pyrolysis products was elucidated through the pyrolytic decomposition of phenyl azide. It is demonstrated that the intermediate phenyl nitrene generated reacts with elemental carbon at the filament surface, leading...

Directional and dynamic modulation of the optical emission of an individual GaAs nanowire using surface acoustic waves.

Science.gov (United States)

Kinzel, Jörg B; Rudolph, Daniel; Bichler, Max; Abstreiter, Gerhard; Finley, Jonathan J; Koblmüller, Gregor; Wixforth, Achim; Krenner, Hubert J

2011-04-13

We report on optical experiments performed on individual GaAs nanowires and the manipulation of their temporal emission characteristics using a surface acoustic wave. We find a pronounced, characteristic suppression of the emission intensity for the surface acoustic wave propagation aligned with the axis of the nanowire. Furthermore, we demonstrate that this quenching is dynamical as it shows a pronounced modulation as the local phase of the surface acoustic wave is tuned. These effects are strongly reduced for a surface acoustic wave applied in the direction perpendicular to the axis of the nanowire due to their inherent one-dimensional geometry. We resolve a fully dynamic modulation of the nanowire emission up to 678 MHz not limited by the physical properties of the nanowires.

Direct Fermi-surface image of hidden nesting for NaMo6O17 and KMo6O17

International Nuclear Information System (INIS)

Gweon, G.-.; Allen, J.W.; Clack, J.A.; Zhang, Y.X.; Poirier, D.M.; Benning, P.J.; Olson, C.G.; Marcus, J.; Schlenker, C.

1997-01-01

We report direct Fermi-surface images obtained with angle-resolved photoemission spectroscopy (ARPES) for NaMo 6 O 17 and KMo 6 O 17 above the charge-density wave transition temperatures. We also report ARPES spectra of the valence band of NaMo 6 O 17 . The images imply a Fermi surface (FS) based on three underlying quasi-one-dimensional (quasi-1D) surfaces. Thus it agrees in detail with that expected in the hidden nesting picture of Whangbo et al. [Science 252, 96 (1991)], but differs greatly from a FS deduced in a previous study by Breuer et al. [Phys. Rev. Lett. 76, 3172 (1996)], which found only two underlying quasi-1D surfaces. copyright 1997 The American Physical Society

Airborne hyperspectral observations of surface and cloud directional reflectivity using a commercial digital camera

Directory of Open Access Journals (Sweden)

A. Ehrlich

2012-04-01

Full Text Available Spectral radiance measurements by a digital single-lens reflex camera were used to derive the directional reflectivity of clouds and different surfaces in the Arctic. The camera has been calibrated radiometrically and spectrally to provide accurate radiance measurements with high angular resolution. A comparison with spectral radiance measurements with the Spectral Modular Airborne Radiation measurement sysTem (SMART-Albedometer showed an agreement within the uncertainties of both instruments (6% for both. The directional reflectivity in terms of the hemispherical directional reflectance factor (HDRF was obtained for sea ice, ice-free ocean and clouds. The sea ice, with an albedo of ρ = 0.96 (at 530 nm wavelength, showed an almost isotropic HDRF, while sun glint was observed for the ocean HDRF (ρ = 0.12. For the cloud observations with ρ = 0.62, the cloudbow – a backscatter feature typically for scattering by liquid water droplets – was covered by the camera. For measurements above heterogeneous stratocumulus clouds, the required number of images to obtain a mean HDRF that clearly exhibits the cloudbow has been estimated at about 50 images (10 min flight time. A representation of the HDRF as a function of the scattering angle only reduces the image number to about 10 (2 min flight time.

The measured cloud and ocean HDRF have been compared to radiative transfer simulations. The ocean HDRF simulated with the observed surface wind speed of 9 m s⁻¹ agreed best with the measurements. For the cloud HDRF, the best agreement was obtained by a broad and weak cloudbow simulated with a cloud droplet effective radius of R_eff = 4 μm. This value agrees with the particle sizes derived from in situ measurements and retrieved from the spectral radiance of the SMART-Albedometer.

The effect of nanoscratching direction on the plastic deformation and surface morphology of InP crystals

Energy Technology Data Exchange (ETDEWEB)

Huang, J. Y.; Ponce, F. A. [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States); Caldas, P. G.; Prioli, R. [Departamento de Física, Pontificia Universidade Católica do Rio de Janeiro, Marques de São Vicente 225, Rio de Janeiro, 22453-900 Rio de Janeiro (Brazil); Almeida, C. M. [Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Technología (INMETRO), Duque de Caxias, Rio de Janeiro 25250-020 (Brazil)

2013-11-28

The microstructure of (001) InP crystals scratched with a sharp diamond tip depends strongly on the scratching direction. The scratch surface is found to conform to the radius of curvature of the tip (∼60 nm) by the formation of atomic crystal steps produced by dislocation glide along (111) planes. 〈110〉 scratches lead to coherent local crystal lattice movement and rotation causing deep dislocation propagation into the crystal and irregular pileups at the sides of the scratch surface. 〈100〉 scratches lead to incoherent lattice movement causing dislocation locking that inhibits their propagation and results in regular pileups.

Serial number coding and decoding by laser interference direct patterning on the original product surface for anti-counterfeiting.

Science.gov (United States)

Park, In-Yong; Ahn, Sanghoon; Kim, Youngduk; Bae, Han-Sung; Kang, Hee-Shin; Yoo, Jason; Noh, Jiwhan

2017-06-26

Here, we investigate a method to distinguish the counterfeits by patterning multiple reflective type grating directly on the surface of the original product and analyze the serial number from its rotation angles of diffracted fringes. The micro-sized gratings were fabricated on the surface of the material at high speeds by illuminating the interference fringe generated by passing a high-energy pulse laser through the Fresnel biprism. In addition, analysis of the grating's diffraction fringes was performed using a continuous wave laser.

Fabrication of hydrophobic structures on coronary stent surface based on direct three-beam laser interference lithography

Science.gov (United States)

Gao, Long-yue; Zhou, Wei-qi; Wang, Yuan-bo; Wang, Si-qi; Bai, Chong; Li, Shi-ming; Liu, Bin; Wang, Jun-nan; Cui, Cheng-kun; Li, Yong-liang

2016-05-01

To solve the problems with coronary stent implantation, coronary artery stent surface was directly modified by three-beam laser interference lithography through imitating the water-repellent surface of lotus leaf, and uniform micro-nano structures with the controllable period were fabricated. The morphological properties and contact angle (CA) of the microstructure were measured by scanning electron microscope (SEM) and CA system. The water repellency of stent was also evaluated by the contact and then separation between the water drop and the stent. The results show that the close-packed concave structure with the period of about 12 μm can be fabricated on the stent surface with special parameters (incident angle of 3°, laser energy density of 2.2 J·cm-2 and exposure time of 80 s) by using the three-beam laser at 1 064 nm, and the structure has good water repellency with CA of 120°.

Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant: direct brine release

International Nuclear Information System (INIS)

Stoelzel, D.M.; O'Brien, D.G.; Garner, J.W.; Helton, J.C.; Johnson, J.D.; Smith, L.N.

2000-01-01

The following topics related to the treatment of direct brine releases to the surface environment in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (i) mathematical description of models; (ii) uncertainty and sensitivity analysis results arising from subjective (i.e. epistemic) uncertainty for individual releases; (iii) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e. aleatory) uncertainty; and (iv) uncertainty and sensitivity analysis results for CCDFs. The presented analyses indicate that direct brine releases do not constitute a serious threat to the effectiveness of the WIPP as a disposal facility for transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for direct brine releases fall substantially to the left of the boundary line specified in the US Environmental Protection Agency's standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194)

SURFACE WATER POLLUTION WITH HEAVY METALS IN THE LOWER CATCHMENT OF JIU RIVER BASIN, ACCORDING TO THE WATER FRAMEWORK DIRECTIVE (2000/60/EC

Directory of Open Access Journals (Sweden)

ADINA SANDA ŞERBAN

2011-03-01

Full Text Available Surface water pollution with heavy metals in the lower catchment of Jiu river basin, according to the Water Framework Directive (2000/60/EC. The Water Framework Directive establishes a single transparent, effective and coherent water policy by defining a strategy to combat pollution by requiring specific action programs.Chemical pollution of surface water presents a threat to the aquatic environment with acute and chronic toxicity to aquatic organisms, accumulation in the ecosystem and losses of habitats and biodiversity, as well as a threat to human health (art.1 from Directive 2008/105/EC regarding the environmental quality standards for water policy.The purpose of this study is to evaluate the chemical status for surface water bodies in the lower catchment of Jiu river basin. The assessment was made taking into account the water impact of four heavy metals: cadmium (Cd, nickel (Ni, mercury (Hg and lead (Pb.

Direct Effect of Dielectric Surface Energy on Carrier Transport in Organic Field-Effect Transistors.

Science.gov (United States)

Zhou, Shujun; Tang, Qingxin; Tian, Hongkun; Zhao, Xiaoli; Tong, Yanhong; Barlow, Stephen; Marder, Seth R; Liu, Yichun

2018-05-09

The understanding of the characteristics of gate dielectric that leads to optimized carrier transport remains controversial, and the conventional studies applied organic semiconductor thin films, which introduces the effect of dielectric on the growth of the deposited semiconductor thin films and hence only can explore the indirect effects. Here, we introduce pregrown organic single crystals to eliminate the indirect effect (semiconductor growth) in the conventional studies and to undertake an investigation of the direct effect of dielectric on carrier transport. It is shown that the matching of the polar and dispersive components of surface energy between semiconductor and dielectric is favorable for higher mobility. This new empirical finding may show the direct relationship between dielectric and carrier transport for the optimized mobility of organic field-effect transistors and hence show a promising potential for the development of next-generation high-performance organic electronic devices.

Direct Measurement of Surface Dissolution Rates in Potential Nuclear Waste Forms: The Example of Pyrochlore.

Science.gov (United States)

Fischer, Cornelius; Finkeldei, Sarah; Brandt, Felix; Bosbach, Dirk; Luttge, Andreas

2015-08-19

The long-term stability of ceramic materials that are considered as potential nuclear waste forms is governed by heterogeneous surface reactivity. Thus, instead of a mean rate, the identification of one or more dominant contributors to the overall dissolution rate is the key to predict the stability of waste forms quantitatively. Direct surface measurements by vertical scanning interferometry (VSI) and their analysis via material flux maps and resulting dissolution rate spectra provide data about dominant rate contributors and their variability over time. Using pyrochlore (Nd2Zr2O7) pellet dissolution under acidic conditions as an example, we demonstrate the identification and quantification of dissolution rate contributors, based on VSI data and rate spectrum analysis. Heterogeneous surface alteration of pyrochlore varies by a factor of about 5 and additional material loss by chemo-mechanical grain pull-out within the uppermost grain layer. We identified four different rate contributors that are responsible for the observed dissolution rate range of single grains. Our new concept offers the opportunity to increase our mechanistic understanding and to predict quantitatively the alteration of ceramic waste forms.

Multi-directional plasmonic surface-wave splitters with full bandwidth isolation

International Nuclear Information System (INIS)

Gao, Zhen; Gao, Fei; Zhang, Baile

2016-01-01

We present a multidirectional plasmonic surface-wave splitter with full bandwidth isolation experimentally based on coupled defect surface modes in a surface-wave photonic crystal. In contrast to conventional plasmonic surface-wave frequency splitters with polaritonic dispersion relations that overlap at low frequencies, this multidirectional plasmonic surface-wave splitter based on coupled defect surface modes can split different frequency bands into different waveguide branches without bandwidth overlap. Transmission spectra and near-field imaging measurements have been implemented in the microwave frequencies to verify the performance of the multidirectional plasmonic surface-wave splitter. This surface wave structure can be used as a plasmonic wavelength-division multiplexer that may find potential applications in the surface-wave integrated circuits from microwave to terahertz frequencies.

TWO METHODS FOR REMOTE ESTIMATION OF COMPLETE URBAN SURFACE TEMPERATURE

Directory of Open Access Journals (Sweden)

L. Jiang

2017-09-01

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

Direct Observation of Asperity Deformation of Specimen with Random Rough Surface in Upsetting Process

DEFF Research Database (Denmark)

Azushima, A.; Kuba, S.; Tani, S.

2004-01-01

The trapping behavior of liquid lubricant and contact behavior of asperities at the workpiece-tool interface during upsetting and indentation are observed directly using a compression subpress which consists of a transparent die made of sapphire, a microscope with a CCD camera and a video system....... The experiments are carried out without lubricant and with lubricant. Specimens used are commercially pure A1100 Aluminum with a random rough surface. From this observation, the change in the fraction of real contact area is measured by an image processor. The real contact area ratios in upsetting experiment...

Directed Acceleration of Electrons from a Solid Surface by Sub-10-fs Laser Pulses

International Nuclear Information System (INIS)

Brandl, F.; Hidding, B.; Osterholz, J.; Hemmers, D.; Pretzler, G.; Karmakar, A.; Pukhov, A.

2009-01-01

Electrons have been accelerated from solid target surfaces by sub-10-fs laser pulses of 120 μJ energy which were focused to an intensity of 2x10 16 W/cm 2 . The electrons have a narrow angular distribution, and their observed energies exceed 150 keV. We show that these energies are not to be attributed to collective plasma effects but are mainly gained directly via repeated acceleration in the transient field pattern created by incident and reflected laser, alternating with phase-shift-generating scattering events in the solid.

In vitro performance of DIAGNOdent laser fluorescence device for dental calculus detection on human tooth root surfaces.

Science.gov (United States)

Rams, Thomas E; Alwaqyan, Abdulaziz Y

2017-10-01

This study assessed the reproducibility of a red diode laser device, and its capability to detect dental calculus in vitro on human tooth root surfaces. On each of 50 extracted teeth, a calculus-positive and calculus-free root surface was evaluated by two independent examiners with a low-power indium gallium arsenide phosphide diode laser (DIAGNOdent) fitted with a periodontal probe-like sapphire tip and emitting visible red light at 655 nm wavelength. Laser autofluorescence intensity readings of examined root surfaces were scored on a 0-99 scale, with duplicate assessments performed using the laser probe tip directed both perpendicular and parallel to evaluated tooth root surfaces. Pearson correlation coefficients of untransformed measurements, and kappa analysis of data dichotomized with a >40 autofluorescence intensity threshold, were calculated to assess intra- and inter-examiner reproducibility of the laser device. Mean autofluorescence intensity scores of calculus-positive and calculus-free root surfaces were evaluated with the Student's t -test. Excellent intra- and inter-examiner reproducibility was found for DIAGNOdent laser autofluorescence intensity measurements, with Pearson correlation coefficients above 94%, and kappa values ranging between 0.96 and 1.0, for duplicate readings taken with both laser probe tip orientations. Significantly higher autofluorescence intensity values were measured when the laser probe tip was directed perpendicular, rather than parallel, to tooth root surfaces. However, calculus-positive roots, particularly with calculus in markedly-raised ledges, yielded significantly greater mean DIAGNOdent laser autofluorescence intensity scores than calculus-free surfaces, regardless of probe tip orientation. DIAGNOdent autofluorescence intensity values >40 exhibited a stronger association with calculus (36.6 odds ratio) then measurements of ≥5 (20.1 odds ratio) when the laser probe tip was advanced parallel to root surfaces. Excellent

Self-assembling siloxane bilayer directly on SiO2 surface of micro-cantilevers for long-term highly repeatable sensing to trace explosives.

Science.gov (United States)

Chen, Ying; Xu, Pengcheng; Li, Xinxin

2010-07-02

This paper presents a novel sensing layer modification technique for static micro-cantilever sensors that detect trace explosives by measuring specific adsorption-induced surface stress. For the first time, a method of directly modifying a siloxane sensing bilayer on an SiO(2) surface is proposed to replace the conventional self-assembled monolayers (SAMs) of thiols on Au to avoid the trouble from long-term unstable Au-S bonds. For modifying the long-term reliable sensing bilayer on the piezoresistor-integrated micro-cantilevers, a siloxane-head bottom layer is self-assembled directly on the SiO(2) cantilever surface, which is followed by grafting another explosive-sensing-group functionalized molecule layer on top of the siloxane layer. The siloxane-modified sensor has experimentally exhibited a highly resoluble response to 0.1 ppb TNT vapor. More importantly, the repeated detection results after 140 days show no obvious attenuation in sensing signal. Also observed experimentally, the specific adsorption of the siloxane sensing bilayer to TNT molecules causes a tensile surface stress on the cantilever. Herein the measured tensile surface stress is in contrast to the compressive surface stress normally measured from conventional cantilever sensors where the sensitive thiol-SAMs are modified on an Au surface. The reason for this newly observed phenomenon is discussed and preliminarily analyzed.

Self-assembling siloxane bilayer directly on SiO2 surface of micro-cantilevers for long-term highly repeatable sensing to trace explosives

International Nuclear Information System (INIS)

Chen Ying; Xu Pengcheng; Li Xinxin

2010-01-01

This paper presents a novel sensing layer modification technique for static micro-cantilever sensors that detect trace explosives by measuring specific adsorption-induced surface stress. For the first time, a method of directly modifying a siloxane sensing bilayer on an SiO 2 surface is proposed to replace the conventional self-assembled monolayers (SAMs) of thiols on Au to avoid the trouble from long-term unstable Au-S bonds. For modifying the long-term reliable sensing bilayer on the piezoresistor-integrated micro-cantilevers, a siloxane-head bottom layer is self-assembled directly on the SiO 2 cantilever surface, which is followed by grafting another explosive-sensing-group functionalized molecule layer on top of the siloxane layer. The siloxane-modified sensor has experimentally exhibited a highly resoluble response to 0.1 ppb TNT vapor. More importantly, the repeated detection results after 140 days show no obvious attenuation in sensing signal. Also observed experimentally, the specific adsorption of the siloxane sensing bilayer to TNT molecules causes a tensile surface stress on the cantilever. Herein the measured tensile surface stress is in contrast to the compressive surface stress normally measured from conventional cantilever sensors where the sensitive thiol-SAMs are modified on an Au surface. The reason for this newly observed phenomenon is discussed and preliminarily analyzed.

Direct chemical synthesis of MnO2 nanowhiskers on MXene surfaces for supercapacitor applications

KAUST Repository

Baby, Rakhi Raghavan

2016-07-05

Transition metal carbides (MXenes) are an emerging class of two dimensional (2D) materials with promising electrochemical energy storage performance. Herein, for the first time, by direct chemical synthesis, nanocrystalline ε-MnO2 whiskers were formed on MXene nanosheet surfaces (ε-MnO2/Ti2CTx and ε-MnO2/Ti3C2Tx) to make nanocomposite electrodes for aqueous pseudocapacitors. The ε-MnO2 nanowhiskers increase the surface area of the composite electrode and enhance the specific capacitance by nearly three orders of magnitude compared to pure MXene based symmetric supercapacitors. Combined with enhanced pseudocapacitance, the fabricated ε-MnO2/MXene supercapacitors exhibited excellent cycling stability with ~88% of the initial specific capacitance retained after 10000 cycles which is much higher than pure ε-MnO2 based supercapacitors (~74%). The proposed electrode structure capitalizes on the high specific capacitance of MnO2 and the ability of MXenes to improve conductivity and cycling stability.

Direct protein quantification in complex sample solutions by surface-engineered nanorod probes

KAUST Repository

Schrittwieser, Stefan

2017-06-30

Detecting biomarkers from complex sample solutions is the key objective of molecular diagnostics. Being able to do so in a simple approach that does not require laborious sample preparation, sophisticated equipment and trained staff is vital for point-of-care applications. Here, we report on the specific detection of the breast cancer biomarker sHER2 directly from serum and saliva samples by a nanorod-based homogeneous biosensing approach, which is easy to operate as it only requires mixing of the samples with the nanorod probes. By careful nanorod surface engineering and homogeneous assay design, we demonstrate that the formation of a protein corona around the nanoparticles does not limit the applicability of our detection method, but on the contrary enables us to conduct in-situ reference measurements, thus further strengthening the point-of-care applicability of our method. Making use of sandwich assays on top of the nanorods, we obtain a limit of detection of 110 pM and 470 pM in 10-fold diluted spiked saliva and serum samples, respectively. In conclusion, our results open up numerous applications in direct protein biomarker quantification, specifically in point-of-care settings where resources are limited and ease-of-use is of essence.

Direct protein quantification in complex sample solutions by surface-engineered nanorod probes

KAUST Repository

Schrittwieser, Stefan; Pelaz, Beatriz; Parak, Wolfgang J.; Lentijo Mozo, Sergio; Soulantica, Katerina; Dieckhoff, Jan; Ludwig, Frank; Schotter, Joerg

2017-01-01

Detecting biomarkers from complex sample solutions is the key objective of molecular diagnostics. Being able to do so in a simple approach that does not require laborious sample preparation, sophisticated equipment and trained staff is vital for point-of-care applications. Here, we report on the specific detection of the breast cancer biomarker sHER2 directly from serum and saliva samples by a nanorod-based homogeneous biosensing approach, which is easy to operate as it only requires mixing of the samples with the nanorod probes. By careful nanorod surface engineering and homogeneous assay design, we demonstrate that the formation of a protein corona around the nanoparticles does not limit the applicability of our detection method, but on the contrary enables us to conduct in-situ reference measurements, thus further strengthening the point-of-care applicability of our method. Making use of sandwich assays on top of the nanorods, we obtain a limit of detection of 110 pM and 470 pM in 10-fold diluted spiked saliva and serum samples, respectively. In conclusion, our results open up numerous applications in direct protein biomarker quantification, specifically in point-of-care settings where resources are limited and ease-of-use is of essence.

Label-free direct surface-enhanced Raman scattering (SERS) of nucleic acids (Conference Presentation)

Science.gov (United States)

Guerrini, Luca; Morla-Folch, Judit; Gisbert-Quilis, Patricia; Xie, Hainan; Alvarez-Puebla, Ramon

2016-03-01

Recently, plasmonic-based biosensing has experienced an unprecedented level of attention, with a particular focus on the nucleic acid detection, offering efficient solutions to engineer simple, fast, highly sensitive sensing platforms while overcoming important limitations of PCR and microarray techniques. In the broad field of plasmonics, surface-enhanced Raman scattering (SERS) spectroscopy has arisen as a powerful analytical tool for detection and structural characterization of biomolecules. Today applications of SERS to nucleic acid analysis largely rely on indirect strategies, which have been demonstrated very effective for pure sensing purposes but completely dismiss the exquisite structural information provided by the direct acquisition of the biomolecular vibrational fingerprint. Contrarily, direct label-free SERS of nucleic acid shows an outstanding potential in terms of chemical-specific information which, however, remained largely unexpressed mainly because of the inherent poor spectral reproducibility and/or limited sensitivity. To address these limitations, we developed a fast and affordable high-throughput screening direct SERS method for gaining detailed genomic information on nucleic acids (DNA and RNA) and for the characterization and quantitative recognition of DNA interactions with exogenous agents. The simple strategy relies on the electrostatic adhesion of DNA/RNA onto positively-charged silver colloids that promotes the nanoparticle aggregation into stable clusters yielding intense and reproducible SERS spectra at picogram level (i.e. the analysis can be performed without the necessity of amplification steps thus providing realistic direct information of the nucleic acid in its native state). We anticipate this method to gain a vast impact and set of applications in different fields, including medical diagnostics, genomic screening, drug discovery, forensic science and even molecular electronics.

Inkjet printing for direct micropatterning of a superhydrophobic surface: Toward biomimetic fog harvesting surfaces

KAUST Repository

Zhang, Lianbin; Wu, Jinbo; Hedhili, Mohamed N.; Yang, Xiulin; Wang, Peng

2015-01-01

water collection efficiency compared with uniform superhydrophilic and superhydrophobic surfaces. This method can be used for the facile large-scale patterning of superhydrophobic surfaces with high precision and superior pattern stability

Direct microvascular monitoring of a free autologous jejunal flap using microendoscopy: a case report

Directory of Open Access Journals (Sweden)

Hopper Colin

2006-09-01

Full Text Available Abstract Background Early identification of flap failure is an indispensable prerequisite for flap salvage. Although many technical developments of free flap monitoring have now reached clinical application, very few are considered to be reliable and non-invasive for early recognition of flap failure. Case presentation We used microendoscopic technique for microvascular monitoring of free autologous jejunal flap by the direct visualisation of the flow of erythrocytes through the capillary vasculature on both the mucosal and serosal surfaces. Blood flow was seen to be pulsatile, with individual erythrocytes visible in the capillaries. The best view was obtained when the scope was focussed directly on the capillary rather than the graft surface. The view of the unstained mucosal surface was bland apart from the fine capillary loops which were seen to fill with each pulsatile event. The microendoscopic examination of the serosal surface revealed much larger calibre vessels with obvious blood flow. Conclusion The microendoscopic monitoring technique is simple and safe with direct visualisation of blood flow. The technique may also be useful for the monitoring of other free bowel transplants.

A polygon-surface reference Korean male phantom (PSRK-Man) and its direct implementation in Geant4 Monte Carlo simulation

Energy Technology Data Exchange (ETDEWEB)

Kim, Chan Hyeong; Jeong, Jong Hwi [Department of Nuclear Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Bolch, Wesley E [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Cho, Kun-Woo [Korea Institute of Nuclear Safety, 19 Guseong-dong, Yuseong-gu, Daejeon 305-600 (Korea, Republic of); Hwang, Sung Bae, E-mail: chkim@hanyang.ac.kr [Department of Physical Therapy, Kyungbuk College, Hyucheon 2-dong, Yeongju-si, Gyeongbuk 750-712 (Korea, Republic of)

2011-05-21

Even though the hybrid phantom embodies both the anatomic reality of voxel phantoms and the deformability of stylized phantoms, it must be voxelized to be used in a Monte Carlo code for dose calculation or some imaging simulation, which incurs the inherent limitations of voxel phantoms. In the present study, a voxel phantom named VKH-Man (Visible Korean Human-Man), was converted to a polygon-surface phantom (PSRK-Man, Polygon-Surface Reference Korean-Man), which was then adjusted to the Reference Korean data. Subsequently, the PSRK-Man polygon phantom was directly, without any voxelization process, implemented in the Geant4 Monte Carlo code for dose calculations. The calculated dose values and computation time were then compared with those of HDRK-Man (High Definition Reference Korean-Man), a corresponding voxel phantom adjusted to the same Reference Korean data from the same VKH-Man voxel phantom. Our results showed that the calculated dose values of the PSRK-Man surface phantom agreed well with those of the HDRK-Man voxel phantom. The calculation speed for the PSRK-Man polygon phantom though was 70-150 times slower than that of the HDRK-Man voxel phantom; that speed, however, could be acceptable in some applications, in that direct use of the surface phantom PSRK-Man in Geant4 does not require a separate voxelization process. Computing speed can be enhanced, in future, either by optimizing the Monte Carlo transport kernel for the polygon surfaces or by using modern computing technologies such as grid computing and general-purpose computing on graphics processing units programming.

A polygon-surface reference Korean male phantom (PSRK-Man) and its direct implementation in Geant4 Monte Carlo simulation

International Nuclear Information System (INIS)

Kim, Chan Hyeong; Jeong, Jong Hwi; Bolch, Wesley E; Cho, Kun-Woo; Hwang, Sung Bae

2011-01-01

Even though the hybrid phantom embodies both the anatomic reality of voxel phantoms and the deformability of stylized phantoms, it must be voxelized to be used in a Monte Carlo code for dose calculation or some imaging simulation, which incurs the inherent limitations of voxel phantoms. In the present study, a voxel phantom named VKH-Man (Visible Korean Human-Man), was converted to a polygon-surface phantom (PSRK-Man, Polygon-Surface Reference Korean-Man), which was then adjusted to the Reference Korean data. Subsequently, the PSRK-Man polygon phantom was directly, without any voxelization process, implemented in the Geant4 Monte Carlo code for dose calculations. The calculated dose values and computation time were then compared with those of HDRK-Man (High Definition Reference Korean-Man), a corresponding voxel phantom adjusted to the same Reference Korean data from the same VKH-Man voxel phantom. Our results showed that the calculated dose values of the PSRK-Man surface phantom agreed well with those of the HDRK-Man voxel phantom. The calculation speed for the PSRK-Man polygon phantom though was 70-150 times slower than that of the HDRK-Man voxel phantom; that speed, however, could be acceptable in some applications, in that direct use of the surface phantom PSRK-Man in Geant4 does not require a separate voxelization process. Computing speed can be enhanced, in future, either by optimizing the Monte Carlo transport kernel for the polygon surfaces or by using modern computing technologies such as grid computing and general-purpose computing on graphics processing units programming.

Results of the study of entrance surface dose from conventional examinations in diagnostic radiology

International Nuclear Information System (INIS)

Martinez, A.; Jova, L.; Carrazana, J.; Diaz, E.; Mora, R. de la; Guevara, C.; Fleitas, I.

2001-01-01

The wide diffusion of X-ray diagnostic together with the quick development and expansion that has come with experiencing the technology in this practice, has motivated the emission of recommendations in the Basic Safety Standards of the IAEA for the establishment of guidance levels for different radiological examinations in each country that allow the optimization of the medical exposure. Considering the above-mentioned and the existence in Cuba in a great number of conventional X-ray equipment, with an average of over 10 years of use which influences directly on the patient dose, in 1999, an investigation began in the country on the patient exposure in this practice. This work shows the first results of measurements carried out in 9 major hospitals of several provinces of the country. The doses were evaluated in the examinations of lumbar spine AP, lumbar spine LAT, thorax PA, skull AP and skull LAT. The determination of the doses in these examinations was carried out by 'in-vivo' measurements on the patients, placing in the center of the irradiation field TLD of LiF. The distributions obtained in the studies are compared with the guidance levels that is shown in the Basic Safety Standards of the IAEA. (author)

Identification of distant drug off-targets by direct superposition of binding pocket surfaces.

Science.gov (United States)

Schumann, Marcel; Armen, Roger S

2013-01-01

Correctly predicting off-targets for a given molecular structure, which would have the ability to bind a large range of ligands, is both particularly difficult and important if they share no significant sequence or fold similarity with the respective molecular target ("distant off-targets"). A novel approach for identification of off-targets by direct superposition of protein binding pocket surfaces is presented and applied to a set of well-studied and highly relevant drug targets, including representative kinases and nuclear hormone receptors. The entire Protein Data Bank is searched for similar binding pockets and convincing distant off-target candidates were identified that share no significant sequence or fold similarity with the respective target structure. These putative target off-target pairs are further supported by the existence of compounds that bind strongly to both with high topological similarity, and in some cases, literature examples of individual compounds that bind to both. Also, our results clearly show that it is possible for binding pockets to exhibit a striking surface similarity, while the respective off-target shares neither significant sequence nor significant fold similarity with the respective molecular target ("distant off-target").

Examination of returned solar-max surfaces for impacting orbital debris and meteoroids

Science.gov (United States)

Kessler, D. J.; Zook, H. A.; Potter, A. E.; Mckay, D. S.; Clanton, U. S.; Warren, J. L.; Watts, L. A.; Schultz, R. A.; Schramm, L. S.; Wentworth, S. J.

1985-01-01

Previous theoretical studies predicted that in certain regions of earth orbit, the man-made earth orbiting debris environment will soon exceed the interplanetary meteoroid environment for sizes smaller than 1 cm. The surfaces returned from the repaired Solar Max Mission (SMM) by STS 41-C on April 12, 1984, offered an excellent opportunity to examine both the debris and meteoroid environments. To date, approximately 0.7 sq. met. of the thermal insulation and 0.05 sq. met of the aluminum louvers have been mapped by optical microscope for crater diameters larger than 40 microns. Craters larger in diameter than about 100 microns found on the initial 75 micron thick Kapton first sheet on the MEB (Main Electronics Box) blanket are actually holes and constitute perforations through that blanket. The following populations have been found to date in impact sites on these blankets: (1) meteoritic material; (2) thermal paint particles; (3) aluminum droplets; and (4) waste particles.

Isolation and Characterization of Surface and Subsurface Bacteria in Seawater of Mantanani Island, Kota Belud, Sabah by Direct and Enrichment Techniques

International Nuclear Information System (INIS)

Benard, L D; Tuah, P M; Suadin, E G; Jamian, N

2015-01-01

The distribution of hydrocarbon-utilizing bacterial may vary between surface and subsurface of the seawater. One of the identified contributors is the Total Petroleum Hydrocarbon. The isolation and characterization of bacteria using Direct and Enrichment techniques helps in identifying dominant bacterial populations in seawater of Mantanani Island, Kota Belud, Sabah, potential of further investigation as hydrocarbon degrader. Crude oil (5% v/v) was added as the carbon source for bacteria in Enrichment technique. For surface seawater, the highest population of bacteria identified for both Direct and Enrichment technique were 2.60 × 10 7 CFU/mL and 3.84 × 10 6 CFU/mL respectively. Meanwhile, for subsurface seawater, the highest population of bacteria identified for both Direct and Enrichment technique were 5.21 × 10 6 CFU/mL and 8.99 × 10 7 CFU/mL respectively. Dominant species in surface seawater were characterized as Marinobacter hydrocarbonoclasticus-RMSF-C1 and RMSF-C2 and Alcanivorax borkumensis-RMSF-C3, RMSF-C4 and RMSF-C5. As for subsurface seawater, dominant species were characterized as Pseudomonas luteola-SSBR-W1, Burkholderia cepacia-SSBR-C1, Rhizobium radiobacter- SSBR-C3 and Leuconostoc-cremois -SSBR-C4. (paper)

Techniques of surface optical breakdown prevention for low-depths femtosecond waveguides writing

International Nuclear Information System (INIS)

Bukharin, M A; Skryabin, N N; Ganin, D V; Khudyakov, D V; Vartapetov, S.K.

2016-01-01

We demonstrated technique of direct femtosecond waveguide writing at record low depth (2-15 μm) under surface of lithium niobate, that play a key role in design of electrooptical modulators with low operating voltage. To prevent optical breakdown of crystal surface we used high numerical aperture objectives for focusing of light and non-thermal regime of inscription in contrast to widespread femtosecond writing technique at depths of tens micrometers or higher. Surface optical breakdown threshold was measured for both x- and z- cut crystals. Inscribed waveguides were examined for intrinsic microstructure. It also reported sharp narrowing of operating pulses energy range with writing depth under the surface of crystal, that should be taken in account when near-surface waveguides design. Novelty of the results consists in reduction of inscription depth under the surface of crystals that broadens applications of direct femtosecond writing technique to full formation of near-surface waveguides and postproduction precise geometry correction of near-surfaces optical integrated circuits produced with proton-exchanged technique. (paper)

Examination of Surface Residuals Obtained During Re-Lubrication of the International Space Station (ISS) Solar Alpha Rotary Joint (SARJ)

Science.gov (United States)

Martinez, J. E.; Golden, J. L.

2012-01-01

The starboard SARJ mechanism on the ISS suffered a premature lubrication failure, resulting in widespread loss of the nitride case layer on its 10.3 meter circumference, 15-5PH steel race ring [1, 2]. To restore functionality, vacuum-stable grease was applied on-orbit, first to the port SARJ mechanism to save it from the damage suffered by the starboard mechanism. After 3 years of greased operation, telemetry indicated that the port mechanism required relubrication, so part of that process included sampling each of the three race ring surfaces to evaluate any wear debris recovered and the state of the originally applied grease. Extensive microscopic examination was conducted, which directed subsequent microanalysis of particulate. Since the SARJ mechanism operates in the vacuum of space, a sampling method and tool had to be developed for use by astronauts while working in the extravehicular mobility unit (EMU). The sampling tool developed was a cotton terry-cloth mitt for the EMU glove, with samples taken by swiping each of the three port SARJ race-ring surfaces. The sample mitts for each surface were folded inward after sampling to preserve sample integrity, for return and ground analysis. The sample mitt for what is termed the outer canted surface of the SARJ race-ring is shown in Figure 1. Figure 1 also demonstrates how increasing levels of magnification were used to survey the contamination removed in sampling, specifically looking for signs of wear debris or other features which could be further evaluated using Scanning Electron Microscopy (SEM) methods. The most surprising overall result at this point in the analysis was the relatively small amounts of grease recovered during sampling. It is clear that the mechanism was not operating with surplus lubricant. Obviously, evidence of molybdenum disulfide (MoS2), a major component in the grease applied, was prevalent in the analysis conducted. But a small amount of mechanism wear debris was observed. Figure 2

Impedimetric immunosensor for human serum albumin detection on a direct aldehyde-functionalized silicon nitride surface

Energy Technology Data Exchange (ETDEWEB)

Caballero, David, E-mail: caballero@unistra.fr [Nanobioengineering group-IBEC, Barcelona Science Park, C/ Baldiri Reixach 10-12, 08028 Barcelona (Spain); University of Barcelona, Department of Electronics, C/ Marti i Franques 1, 08028 Barcelona (Spain); Centro de Investigacion Biomedica en Red en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), 50018 Zaragoza (Spain); Martinez, Elena [Nanobioengineering group-IBEC, Barcelona Science Park, C/ Baldiri Reixach 10-12, 08028 Barcelona (Spain); Centro de Investigacion Biomedica en Red en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), 50018 Zaragoza (Spain); Bausells, Joan [Centre Nacional de Microelectronica (CNM-IMB), CSIC, Campus UAB, 08193 Bellaterra (Spain); Errachid, Abdelhamid, E-mail: abdelhamid.errachid-el-salhi@univ-lyon1.fr [Nanobioengineering group-IBEC, Barcelona Science Park, C/ Baldiri Reixach 10-12, 08028 Barcelona (Spain); Universite Claude Bernard - Lyon 1, LSA - UMR 5180, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex (France); Samitier, Josep [Nanobioengineering group-IBEC, Barcelona Science Park, C/ Baldiri Reixach 10-12, 08028 Barcelona (Spain); University of Barcelona, Department of Electronics, C/ Marti i Franques 1, 08028 Barcelona (Spain); Centro de Investigacion Biomedica en Red en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), 50018 Zaragoza (Spain)

2012-03-30

Highlights: Black-Right-Pointing-Pointer An impedimetric label-free immunosensor was developed for the specific detection of human serum albumin proteins. Black-Right-Pointing-Pointer Anti-HSA antibodies were covalently immobilized on silicon nitride surfaces using a direct functionalization methodology. Black-Right-Pointing-Pointer Silicon nitride offers multiple advantages compared to other common materials. Black-Right-Pointing-Pointer The proposed sensor has high sensitivity and good selectivity for the detection of HSA proteins. - Abstract: In this work we report the fabrication and characterization of a label-free impedimetric immunosensor based on a silicon nitride (Si{sub 3}N{sub 4}) surface for the specific detection of human serum albumin (HSA) proteins. Silicon nitride provides several advantages compared with other materials commonly used, such as gold, and in particular in solid-state physics for electronic-based biosensors. However, few Si{sub 3}N{sub 4}-based biosensors have been developed; the lack of an efficient and direct protocol for the integration of biological elements with silicon-based substrates is still one of its the main drawbacks. Here, we use a direct functionalization method for the direct covalent binding of monoclonal anti-HSA antibodies on an aldehyde-functionalized Si-p/SiO{sub 2}/Si{sub 3}N{sub 4} structure. This methodology, in contrast with most of the protocols reported in literature, requires less chemical reagents, it is less time-consuming and it does not need any chemical activation. The detection capability of the immunosensor was tested by performing non-faradaic electrochemical impedance spectroscopy (EIS) measurements for the specific detection of HSA proteins. Protein concentrations within the linear range of 10{sup -13}-10{sup -7} M were detected, showing a sensitivity of 0.128 {Omega} {mu}M{sup -1} and a limit of detection of 10{sup -14} M. The specificity of the sensor was also addressed by studying the

Impedimetric immunosensor for human serum albumin detection on a direct aldehyde-functionalized silicon nitride surface

International Nuclear Information System (INIS)

Caballero, David; Martinez, Elena; Bausells, Joan; Errachid, Abdelhamid; Samitier, Josep

2012-01-01

Highlights: ► An impedimetric label-free immunosensor was developed for the specific detection of human serum albumin proteins. ► Anti-HSA antibodies were covalently immobilized on silicon nitride surfaces using a direct functionalization methodology. ► Silicon nitride offers multiple advantages compared to other common materials. ► The proposed sensor has high sensitivity and good selectivity for the detection of HSA proteins. - Abstract: In this work we report the fabrication and characterization of a label-free impedimetric immunosensor based on a silicon nitride (Si 3 N 4 ) surface for the specific detection of human serum albumin (HSA) proteins. Silicon nitride provides several advantages compared with other materials commonly used, such as gold, and in particular in solid-state physics for electronic-based biosensors. However, few Si 3 N 4 -based biosensors have been developed; the lack of an efficient and direct protocol for the integration of biological elements with silicon-based substrates is still one of its the main drawbacks. Here, we use a direct functionalization method for the direct covalent binding of monoclonal anti-HSA antibodies on an aldehyde-functionalized Si-p/SiO 2 /Si 3 N 4 structure. This methodology, in contrast with most of the protocols reported in literature, requires less chemical reagents, it is less time-consuming and it does not need any chemical activation. The detection capability of the immunosensor was tested by performing non-faradaic electrochemical impedance spectroscopy (EIS) measurements for the specific detection of HSA proteins. Protein concentrations within the linear range of 10 −13 –10 −7 M were detected, showing a sensitivity of 0.128 Ω μM −1 and a limit of detection of 10 −14 M. The specificity of the sensor was also addressed by studying the interferences with a similar protein, bovine serum albumin. The results obtained show that the antibodies were efficiently immobilized and the proteins

Status of the nondestructive examination equipment for the fuels and materials examination facility

International Nuclear Information System (INIS)

Frandsen, G.B.

1980-01-01

The present status of Nondestructive Examination (NDE) Equipment proposed for the Fuels and Materials Examination Facility (FMEF) now under construction at the Hanford Engineering Development Laboratory is discussed. Items discussed include the NDE cell receiving machine, the dismantling machine, the standard examination stage, profilometry, eddy current, wire wrap removal machine, surface examination, gamma scan and general NDE equipment

Motivating women and men to take protective action against rape: examining direct and indirect persuasive fear appeals.

Science.gov (United States)

Morrison, Kelly

2005-01-01

This article examines the effectiveness of persuasive fear appeals in motivating women to enroll in self-defense classes to take protective action against rape. Witte's extended parallel process model is used as a framework to examine the relations between perceived invulnerability, perceived fear, and fear control processes. Because women may perceive invulnerability to rape, persuasive fear appeals targeted toward them may be ineffective in achieving attitude, intention, and behavioral change toward protecting themselves. One possible solution is to persuade men to talk with women about whom they care. Results indicated that women did not perceive invulnerability to rape, and although there was no differential impact between high- and low-threat messages, women did report positive intention and behaviors in response to direct fear appeals. Moreover, men reported positive intention and behaviors in response to indirect fear appeals.

Producer firms, technology diffusion and spillovers to local suppliers : Examining the effects of Foreign Direct Investment and the technology gap

NARCIS (Netherlands)

Jordaan, J.A.

2017-01-01

In this paper, we conduct a detailed examination of the effects of Foreign Direct Investment (FDI) and the technology gap on local technology dissemination and spillovers. Using unique firm level data from surveys among FDI firms and domestic producer firms and a random sample of their suppliers in

Immobilization of oligonucleotide probes on silicon surfaces using biotin–streptavidin system examined with microscopic and spectroscopic techniques

Energy Technology Data Exchange (ETDEWEB)

Awsiuk, K., E-mail: kamil.awsiuk@uj.edu.pl [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, Kraków 30-059 (Poland); Rysz, J. [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, Kraków 30-059 (Poland); Petrou, P. [Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, NCSR “Demokritos”, End Patriarchou Gregoriou Str., Aghia Paraskevi 15310 (Greece); Budkowski, A. [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, Kraków 30-059 (Poland); Bernasik, A. [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, Kraków 30-059 (Poland); Kakabakos, S. [Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, NCSR “Demokritos”, End Patriarchou Gregoriou Str., Aghia Paraskevi 15310 (Greece); Marzec, M.M. [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, Kraków 30-059 (Poland); Raptis, I. [Institute for Advanced Materials, Physicochemical Processes, Nanotechnology and Microsystems, NCSR “Demokritos”, End Patriarchou Gregoriou Str., Aghia Paraskevi 15310 (Greece)

2014-01-30

To immobilize effectively oligonucleotide probes on SiO{sub 2} modified with (3-aminopropyl)triethoxysilane, four procedures based on streptavidin–biotin system are compared with Atomic Force Microscopy, Angle-Resolved X-ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. The first approach involves: adsorption of biotinylated Bovine Serum Albumin, blocking free surface sites with BSA, binding of streptavidin and biotinylated oligonucleotide (b-oligo). Final steps are exchanged in the second procedure with immobilization of preformed streptavidin–b-oligo conjugate. The third approach consists of streptavidin adsorption, blocking with BSA and b-oligo binding. Finally, streptavidin–b-oligo conjugate is immobilized directly within the fourth method. Surface coverage with biomolecules, determined from ARXPS, accords with average AFM height, and is anti-correlated with the intensity of Si+ ions. Higher biomolecular coverage was achieved during the last steps of the first (2.45(±0.38) mg/m{sup 2}) and second (1.31(±0.22) mg/m{sup 2}) approach, as compared to lower surface density resulting from the third (0.58(±0.20) mg/m{sup 2}) and fourth (0.41(±0.11) mg/m{sup 2}) method. Phosphorus atomic concentration indicates effectiveness of oligonucleotide immobilization. Secondary ions intensities, characteristic for oligonucleotides, streptavidin, BSA, and proteins, allow additional insight into overlayer composition. These measurements verify the ARXPS results and show the superiority of the first two immobilization approaches in terms of streptavidin and oligonucleotide density achieved onto the surface.

Immobilization of oligonucleotide probes on silicon surfaces using biotin–streptavidin system examined with microscopic and spectroscopic techniques

International Nuclear Information System (INIS)

Awsiuk, K.; Rysz, J.; Petrou, P.; Budkowski, A.; Bernasik, A.; Kakabakos, S.; Marzec, M.M.; Raptis, I.

2014-01-01

To immobilize effectively oligonucleotide probes on SiO 2 modified with (3-aminopropyl)triethoxysilane, four procedures based on streptavidin–biotin system are compared with Atomic Force Microscopy, Angle-Resolved X-ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. The first approach involves: adsorption of biotinylated Bovine Serum Albumin, blocking free surface sites with BSA, binding of streptavidin and biotinylated oligonucleotide (b-oligo). Final steps are exchanged in the second procedure with immobilization of preformed streptavidin–b-oligo conjugate. The third approach consists of streptavidin adsorption, blocking with BSA and b-oligo binding. Finally, streptavidin–b-oligo conjugate is immobilized directly within the fourth method. Surface coverage with biomolecules, determined from ARXPS, accords with average AFM height, and is anti-correlated with the intensity of Si+ ions. Higher biomolecular coverage was achieved during the last steps of the first (2.45(±0.38) mg/m 2 ) and second (1.31(±0.22) mg/m 2 ) approach, as compared to lower surface density resulting from the third (0.58(±0.20) mg/m 2 ) and fourth (0.41(±0.11) mg/m 2 ) method. Phosphorus atomic concentration indicates effectiveness of oligonucleotide immobilization. Secondary ions intensities, characteristic for oligonucleotides, streptavidin, BSA, and proteins, allow additional insight into overlayer composition. These measurements verify the ARXPS results and show the superiority of the first two immobilization approaches in terms of streptavidin and oligonucleotide density achieved onto the surface.

Selected topics on surface effects in fusion devices: neutral-beam injectors and beam-direct converters

International Nuclear Information System (INIS)

Kaminsky, M.

1978-01-01

Neutral-beam injectors are being used for the heating and fueling of plasmas in existing devices such as PLT (Princeton), ISX (Oak Ridge) and 2XIIB (Lawrence Livermore Laboratory) and will be used in devices such as TFTR (Princeton), MX (Livermore) and Doublet III (Gulf Atomic). For example, TFTR has been designed to receive a total of 20 MW of 120-keV deuterium atoms in pulses of 0.5-sec duration from 12 neutral beam injectors; for the MX experiment it is planned to inject a total of 750A (equivalent) of deuterium atoms with a mean energy of 56 keV in 0.5-sec pulses. The interaction of energetic deuterium atoms with exposed surfaces of device components such as beam dumps, beam-direct-convertors collectors, beam calorimeters, and armor plates, cause a variety of surface effects which affect deleteriously the operation of such devices. Some of the major effects will be discussed

Toward stimulated interaction of surface phonon polaritons

Energy Technology Data Exchange (ETDEWEB)

Kong, B. D.; Trew, R. J.; Kim, K. W., E-mail: kwk@ncsu.edu [Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27695-7911 (United States)

2013-12-21

Thermal emission spectra mediated by surface phonon polariton are examined by using a theoretical model that accounts for generation processes. Specifically, the acoustic phonon fusion mechanism is introduced to remedy theoretical deficiencies of the near thermal equilibrium treatments. The model clarifies the thermal excitation mechanism of surface phonon polaritons and the energy transfer path under non-zero energy flow. When applied to GaAs and SiC semi-infinite surfaces, the nonequilibrium model predicts that the temperature dependence of the quasi-monochromatic peak can exhibit distinctly different characteristics of either sharp increase or slow saturation depending on the materials, which is in direct contrast with the estimate made by the near-equilibrium model. The proposed theoretical tool can accurately analyze the nonequilibrium steady states, potentially paving a pathway to demonstrate stimulated interaction/emission of thermally excited surface phonon polaritons.

Self-assembling siloxane bilayer directly on SiO{sub 2} surface of micro-cantilevers for long-term highly repeatable sensing to trace explosives

Energy Technology Data Exchange (ETDEWEB)

Chen Ying; Xu Pengcheng; Li Xinxin, E-mail: xxli@mail.sim.ac.cn [State Key Lab of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

2010-07-02

This paper presents a novel sensing layer modification technique for static micro-cantilever sensors that detect trace explosives by measuring specific adsorption-induced surface stress. For the first time, a method of directly modifying a siloxane sensing bilayer on an SiO{sub 2} surface is proposed to replace the conventional self-assembled monolayers (SAMs) of thiols on Au to avoid the trouble from long-term unstable Au-S bonds. For modifying the long-term reliable sensing bilayer on the piezoresistor-integrated micro-cantilevers, a siloxane-head bottom layer is self-assembled directly on the SiO{sub 2} cantilever surface, which is followed by grafting another explosive-sensing-group functionalized molecule layer on top of the siloxane layer. The siloxane-modified sensor has experimentally exhibited a highly resoluble response to 0.1 ppb TNT vapor. More importantly, the repeated detection results after 140 days show no obvious attenuation in sensing signal. Also observed experimentally, the specific adsorption of the siloxane sensing bilayer to TNT molecules causes a tensile surface stress on the cantilever. Herein the measured tensile surface stress is in contrast to the compressive surface stress normally measured from conventional cantilever sensors where the sensitive thiol-SAMs are modified on an Au surface. The reason for this newly observed phenomenon is discussed and preliminarily analyzed.

Then and Now: Examining How Consumer Communication and Attitudes of Direct-to-Consumer Pharmaceutical Advertising Have Changed in the Last Decade.

Science.gov (United States)

Wood, Kelly S; Cronley, Maria L

2014-09-01

This study examines changes over a 10-year period in consumer reports of communication with health care providers about direct-to-consumer advertised (DTCA) medications. Two rounds of survey data were collected in 2003 and 2012 using repeated cross-sectional procedures to examine consumer willingness to discuss DTCA medications, content and tone of those conversations, and attitudes about the advertisements. In total, 472 surveys were analyzed. Generally, we found physician-patient conversations, attitudes, and behaviors regarding DTCA have changed. Consumers in 2012 reported talking significantly less about the names of the advertised drug, comparing the advertised drug with their current medication, and sharing general information than consumers in 2003. Attitudes toward the advertisements were significantly more negative in 2012 compared to 2003. Of those who specifically asked for a prescription, the proportion of patients who received the prescription was significantly lower in 2012, despite research suggesting increased rates of prescriptions. These results are interpreted in light of previous research about the lack of research examining the actual communication between physicians and patients on this topic. Limitations of the study are provided along with directions for future research about DTCA and physician-patient communication.

Methods of conditioning direct methanol fuel cells

Science.gov (United States)

Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon

2005-11-08

Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

Synchrotron radiation induced direct photo-etching and surface modification of PTFE

International Nuclear Information System (INIS)

Oshima, Akihiro; Washio, Masakazu

2003-01-01

In the first part of this article, we have described and discussed the measurement results of etching rates by direct photo-etching using Synchrotron Radiation (SR) for various kind of crosslinked PTFEs, which were prepared by different crosslinking doses, comparing with the non-crosslinked PTFE. It has been found that the etching rates obtained for crosslinked PTFE were much larger than that of non-crosslinked one. These results are not described by simple consideration such as the G values of main chain scission. We propose that the etching rates should be discussed by the complex mechanism through at least two different steps such as polymer decomposition and fragment desorption. In the second part of the article, we have described and discussed the abnormal reaction induced at the surface region after the SR etching for non-crosslinked PTFE. Through the measurements using DSC and solid state 19 F-NMR, we have confirmed the crosslinking reaction of PTFE even in solid state PTFE. This should be induced by the very high density radical formation in very thin area of PTFE films by SR radiation. (author)

Multiscale Characterization of Bacterial Swarming Illuminates Principles Governing Directed Surface Motility

Science.gov (United States)

Strickland, Ben; Hoeger, Kentaro; Ursell, Tristan

In many systems, individual characteristics interact, leading to the spontaneous emergence of order and complexity. In biological settings like microbes, such collective behaviors can imbue a variety of benefits to constituent individuals, including increased spatial range, improved access to nutrients, and enhanced resistance to antibiotic threats. To untangle the biophysical underpinnings of collective motility, we use passive tracers and a curated genetic library of Bacillus subtilis, including motile, non-motile, biofilm-deficient, and non-chemotactic mutants. We characterize and connect individual behavior on the microscopic scale to macroscopic colony morphology and motility of dendritic swarming. We analyze the persistence and dynamics of coordinated movement on length scales up to 4 orders of magnitude larger than that of individual cells, revealing rapid and directed responses of microbial groups to external stimuli, such as avoidance dynamics across chemical gradients. Our observations uncover the biophysical interplay between individual motility, surface wetness, phenotypic diversity, and external physical forces that robustly precipitate coordinated group behavior in microbes, and suggest general principles that govern the transition from individual to group behavior.

Terahertz surface plasmon polariton waveguiding with periodic metallic cylinders

KAUST Repository

Zhang, Ying; Li, Shaoxian; Xu, Quan; Tian, Chunxiu; Gu, Jianqiang; Li, Yanfeng; Tian, Zhen; Ouyang, Chunmei; Han, Jiaguang; Zhang, Weili

2017-01-01

We demonstrated a structure with periodic cylinders arranged bilaterally and a thin dielectric layer covered inside that supports bound modes of surface plasmon polaritons at terahertz frequencies. This structure can confine the surface plasmon polaritons in the lateral direction, and at the same time reduce the field expansion into space. We examined and explored the characteristics of several different structures using scanning near-field terahertz microscopy. The proposed designs pave a novel way to terahertz waveguiding and may have important applications in the development of flexible, wideband and compact photonic circuits operating at terahertz frequencies.

Terahertz surface plasmon polariton waveguiding with periodic metallic cylinders

KAUST Repository

Zhang, Ying

2017-06-15

We demonstrated a structure with periodic cylinders arranged bilaterally and a thin dielectric layer covered inside that supports bound modes of surface plasmon polaritons at terahertz frequencies. This structure can confine the surface plasmon polaritons in the lateral direction, and at the same time reduce the field expansion into space. We examined and explored the characteristics of several different structures using scanning near-field terahertz microscopy. The proposed designs pave a novel way to terahertz waveguiding and may have important applications in the development of flexible, wideband and compact photonic circuits operating at terahertz frequencies.

Compact and broadband directional coupling and demultiplexing in dielectric-loaded surface plasmon polariton waveguides based on the multimode interference effect

DEFF Research Database (Denmark)

Zhu, Zhihong; García Ortíz, César Eduardo; Han, Zhanghua

2013-01-01

We theoretically, numerically, and experimentally demonstrate that a directional coupling function can be realized with a wide bandwidth (greater than 200 nm) in dielectric-loaded surface plasmon polariton waveguides based on the multimode interference effect. The functional size of the structure...

Direct measurements of the tile drain and groundwater flow route contributions to surface water contamination: From field-scale concentration patterns in groundwater to catchment-scale surface water quality

International Nuclear Information System (INIS)

Rozemeijer, J.C.; Velde, Y. van der; Geer, F.C. van; Bierkens, M.F.P.; Broers, H.P.

2010-01-01

Enhanced knowledge of water and solute pathways in catchments would improve the understanding of dynamics in water quality and would support the selection of appropriate water pollution mitigation options. For this study, we physically separated tile drain effluent and groundwater discharge from an agricultural field before it entered a 43.5-m ditch transect. Through continuous discharge measurements and weekly water quality sampling, we directly quantified the flow route contributions to surface water discharge and solute loading. Our multi-scale experimental approach allowed us to relate these measurements to field-scale NO 3 concentration patterns in shallow groundwater and to continuous NO 3 records at the catchment outlet. Our results show that the tile drains contributed 90-92% of the annual NO 3 and heavy metal loads. Considering their crucial role in water and solute transport, enhanced monitoring and modeling of tile drainage are important for adequate water quality management. - Direct measurements of flow route contributions to surface water contaminant loading reveal the crucial role of tile drainage for catchment-scale water and solute transport.

Water at surfaces with tunable surface chemistries

Science.gov (United States)

Sanders, Stephanie E.; Vanselous, Heather; Petersen, Poul B.

2018-03-01

Aqueous interfaces are ubiquitous in natural environments, spanning atmospheric, geological, oceanographic, and biological systems, as well as in technical applications, such as fuel cells and membrane filtration. Where liquid water terminates at a surface, an interfacial region is formed, which exhibits distinct properties from the bulk aqueous phase. The unique properties of water are governed by the hydrogen-bonded network. The chemical and physical properties of the surface dictate the boundary conditions of the bulk hydrogen-bonded network and thus the interfacial properties of the water and any molecules in that region. Understanding the properties of interfacial water requires systematically characterizing the structure and dynamics of interfacial water as a function of the surface chemistry. In this review, we focus on the use of experimental surface-specific spectroscopic methods to understand the properties of interfacial water as a function of surface chemistry. Investigations of the air-water interface, as well as efforts in tuning the properties of the air-water interface by adding solutes or surfactants, are briefly discussed. Buried aqueous interfaces can be accessed with careful selection of spectroscopic technique and sample configuration, further expanding the range of chemical environments that can be probed, including solid inorganic materials, polymers, and water immiscible liquids. Solid substrates can be finely tuned by functionalization with self-assembled monolayers, polymers, or biomolecules. These variables provide a platform for systematically tuning the chemical nature of the interface and examining the resulting water structure. Finally, time-resolved methods to probe the dynamics of interfacial water are briefly summarized before discussing the current status and future directions in studying the structure and dynamics of interfacial water.

Direct observation of atoms on surfaces by scanning tunnelling microscopy

International Nuclear Information System (INIS)

Baldeschwieler, J.D.

1989-01-01

The scanning tunnelling microscope is a non-destructive means of achieving atomic level resolution of crystal surfaces in real space to elucidate surface structures, electronic properties and chemical composition. Scanning tunnelling microscope is a powerful, real space surface structure probe complementary to other techniques such as x-ray diffraction. 21 refs., 8 figs

Direct imaging by atomic force microscopy of surface-localized self-assembled monolayers on a cuprate superconductor and surface X-ray scattering analysis of analogous monolayers on the surface of water

DEFF Research Database (Denmark)

Schougaard, Steen B.; Reitzel, Niels; Bjørnholm, Thomas

2007-01-01

A self-assembled monolayer of CF3(CF2)(3)(CH2)(11)NH2 atop the (001) surface of the high-temperature superconductor YBa2Cu3O7-x was imaged by atomic force microscopy (AFM). The AFM images provide direct 2D-structural evidence for the epitaxial 5.5 angstrom square root 2 x root 2R45 degrees unit...... was studied by grazing-incidence X-ray diffraction and specular X-ray reflectivity. Structural differences and similarities between the water-supported and superconductor-localized monolayers are discussed....

Examining the direct and indirect effects of visual-verbal paired associate learning on Chinese word reading.

Science.gov (United States)

Georgiou, George; Liu, Cuina; Xu, Shiyang

2017-08-01

Associative learning, traditionally measured with paired associate learning (PAL) tasks, has been found to predict reading ability in several languages. However, it remains unclear whether it also predicts word reading in Chinese, which is known for its ambiguous print-sound correspondences, and whether its effects are direct or indirect through the effects of other reading-related skills such as phonological awareness and rapid naming. Thus, the purpose of this study was to examine the direct and indirect effects of visual-verbal PAL on word reading in an unselected sample of Chinese children followed from the second to the third kindergarten year. A sample of 141 second-year kindergarten children (71 girls and 70 boys; mean age=58.99months, SD=3.17) were followed for a year and were assessed at both times on measures of visual-verbal PAL, rapid naming, and phonological awareness. In the third kindergarten year, they were also assessed on word reading. The results of path analysis showed that visual-verbal PAL exerted a significant direct effect on word reading that was independent of the effects of phonological awareness and rapid naming. However, it also exerted significant indirect effects through phonological awareness. Taken together, these findings suggest that variations in cross-modal associative learning (as measured by visual-verbal PAL) place constraints on the development of word recognition skills irrespective of the characteristics of the orthography children are learning to read. Copyright © 2017 Elsevier Inc. All rights reserved.

A new geometrical construction using rounded surfaces proposed for the transverse flux machine for direct drive wind turbine

DEFF Research Database (Denmark)

Argeseanu, Alin; Nica, Florin Valentin Traian; Ritchie, Ewen

2014-01-01

This paper proposes a new construction for transverse flux machines (TFM) using a rounded surfaces core geometry. The new concept has been developed for TFM with U core geometry. In this case a new analytic design procedure was proposed. The analytic design of the new TFM construction is further ...... proposed concept is more attractive for the direct-drive wind turbine application....

Efficient diagnostic evaluation of fractures of the talus - an analysis based on examination of 40 patients

International Nuclear Information System (INIS)

Foerster, A.; Roehnert, W.; Koehler, K.

1997-01-01

Conventional radiography imaging the ankle joint in two planes is the initial technique applied, giving information on further diagnostic evaluation required. CT is of importance for such additional examination, and spiral CT in particular, as it can generate directly comparable pictures due to its standardised examination techniques. Joint surfaces are visualized without superpositions. Fractures and their numbers, dislocations as well as involvement of joint surfaces can be better detected. Also, spiral CT, due to the continuous data set generated, permits 2D reconstructions of high quality. 3D Reconstructions as a rule do not supply additional information. CT can be applied for diagnostic evaluation of the tendon and ligamentum system/soft tissue, but MRI will yield better results. (orig./CB) [de

Multi-functional surfaces with controllable wettability and water adhesion

Science.gov (United States)

Anastasiadis, Spiros H.; Frysali, Melani A.; Kenanakis, George; Kaklamani, Georgia; Papoutsakis, Lampros

The design of multifunctional surfaces based on biomimetic structures has gained the interest of the scientific community. Novel multifunctional surfaces have been developed, able to alter their wetting properties in response to temperature and pH as well as light illumination, by combining proper chemistry and surface micro/nano-structuring using ultrafast (femtosecond) laser irradiation. The combination of the hierarchical surface with a ZnO and/or a responsive polymer coating results in efficient photo-active properties as well as reversible superhydrophobic / superhydrophilic surfaces in response to external stimuli. These surfaces can be optimized to exhibit high or zero water adhesion and/or controllable directionality as well. Moreover, they can be seeded with human fibroblasts to examine the cellular response on both surface roughness and surface chemistry. Acknowledgements: This research has been co-financed by the General Secretariat for Research and Technology (''ARISTEIA II'' Action, SMART-SURF) and the European Union (NFFA Europe -Grant agreement No. 654360).

Effect of Surface Modification on Corrosion Resistance of Uncoated and DLC Coated Stainless Steel Surface

Science.gov (United States)

Scendo, Mieczyslaw; Staszewska-Samson, Katarzyna

2017-08-01

Corrosion resistance of 4H13 stainless steel (EN-X46Cr13) surface uncoated and coated with an amorphous hydrogenated carbon (a-C:H) film [diamond-like carbon (DLC)] in acidic chloride solution was investigated. The DLC films were deposited on steel surface by a plasma deposition, direct current discharge (PDCD) method. The Fourier transform infrared (FTIR) was used to determine the chemical groups existing on DLC films. The surface of the specimens was observed by a scanning electron microscope (SEM). The tribological properties of the both materials were examined using a ball-on disk tribometer. The microhardness (HV) of diamond-like carbon film increased over five times in relation to the 4H13 stainless steel without of DLC coating. Oxidation kinetic parameters were determined by gravimetric and electrochemical methods. The high value of polarization resistance indicates that the DLC film on substrate was characterized by low electrical conductivity. The corrosion rate of 4H13 stainless steel with of DLC film decreased about eight times in relation to uncoated surface of 4H13 stainless steel.

When lithography meets self-assembly: a review of recent advances in the directed assembly of complex metal nanostructures on planar and textured surfaces

Science.gov (United States)

Hughes, Robert A.; Menumerov, Eredzhep; Neretina, Svetlana

2017-07-01

One of the foremost challenges in nanofabrication is the establishment of a processing science that integrates wafer-based materials, techniques, and devices with the extraordinary physicochemical properties accessible when materials are reduced to nanoscale dimensions. Such a merger would allow for exacting controls on nanostructure positioning, promote cooperative phenomenon between adjacent nanostructures and/or substrate materials, and allow for electrical contact to individual or groups of nanostructures. With neither self-assembly nor top-down lithographic processes being able to adequately meet this challenge, advancements have often relied on a hybrid strategy that utilizes lithographically-defined features to direct the assembly of nanostructures into organized patterns. While these so-called directed assembly techniques have proven viable, much of this effort has focused on the assembly of periodic arrays of spherical or near-spherical nanostructures comprised of a single element. Work directed toward the fabrication of more complex nanostructures, while still at a nascent stage, has nevertheless demonstrated the possibility of forming arrays of nanocubes, nanorods, nanoprisms, nanoshells, nanocages, nanoframes, core-shell structures, Janus structures, and various alloys on the substrate surface. In this topical review, we describe the progress made in the directed assembly of periodic arrays of these complex metal nanostructures on planar and textured substrates. The review is divided into three broad strategies reliant on: (i) the deterministic positioning of colloidal structures, (ii) the reorganization of deposited metal films at elevated temperatures, and (iii) liquid-phase chemistry practiced directly on the substrate surface. These strategies collectively utilize a broad range of techniques including capillary assembly, microcontact printing, chemical surface modulation, templated dewetting, nanoimprint lithography, and dip-pen nanolithography and

Neural correlates of face and object perception in an awake chimpanzee (Pan troglodytes examined by scalp-surface event-related potentials.

Directory of Open Access Journals (Sweden)

Hirokata Fukushima

Full Text Available BACKGROUND: The neural system of our closest living relative, the chimpanzee, is a topic of increasing research interest. However, electrophysiological examinations of neural activity during visual processing in awake chimpanzees are currently lacking. METHODOLOGY/PRINCIPAL FINDINGS: In the present report, skin-surface event-related brain potentials (ERPs were measured while a fully awake chimpanzee observed photographs of faces and objects in two experiments. In Experiment 1, human faces and stimuli composed of scrambled face images were displayed. In Experiment 2, three types of pictures (faces, flowers, and cars were presented. The waveforms evoked by face stimuli were distinguished from other stimulus types, as reflected by an enhanced early positivity appearing before 200 ms post stimulus, and an enhanced late negativity after 200 ms, around posterior and occipito-temporal sites. Face-sensitive activity was clearly observed in both experiments. However, in contrast to the robustly observed face-evoked N170 component in humans, we found that faces did not elicit a peak in the latency range of 150-200 ms in either experiment. CONCLUSIONS/SIGNIFICANCE: Although this pilot study examined a single subject and requires further examination, the observed scalp voltage patterns suggest that selective processing of faces in the chimpanzee brain can be detected by recording surface ERPs. In addition, this non-invasive method for examining an awake chimpanzee can be used to extend our knowledge of the characteristics of visual cognition in other primate species.

Surface excitation parameter for rough surfaces

International Nuclear Information System (INIS)

Da, Bo; Salma, Khanam; Ji, Hui; Mao, Shifeng; Zhang, Guanghui; Wang, Xiaoping; Ding, Zejun

2015-01-01

Graphical abstract: - Highlights: • Instead of providing a general mathematical model of roughness, we directly use a finite element triangle mesh method to build a fully 3D rough surface from the practical sample. • The surface plasmon excitation can be introduced to the realistic sample surface by dielectric response theory and finite element method. • We found that SEP calculated based on ideal plane surface model are still reliable for real sample surface with common roughness. - Abstract: In order to assess quantitatively the importance of surface excitation effect in surface electron spectroscopy measurement, surface excitation parameter (SEP) has been introduced to describe the surface excitation probability as an average number of surface excitations that electrons can undergo when they move through solid surface either in incoming or outgoing directions. Meanwhile, surface roughness is an inevitable issue in experiments particularly when the sample surface is cleaned with ion beam bombardment. Surface roughness alters not only the electron elastic peak intensity but also the surface excitation intensity. However, almost all of the popular theoretical models for determining SEP are based on ideal plane surface approximation. In order to figure out whether this approximation is efficient or not for SEP calculation and the scope of this assumption, we proposed a new way to determine the SEP for a rough surface by a Monte Carlo simulation of electron scattering process near to a realistic rough surface, which is modeled by a finite element analysis method according to AFM image. The elastic peak intensity is calculated for different electron incident and emission angles. Assuming surface excitations obey the Poisson distribution the SEPs corrected for surface roughness are then obtained by analyzing the elastic peak intensity for several materials and for different incident and emission angles. It is found that the surface roughness only plays an

Polycarbonate surface cell's adhesion examination after Nd:YAG laser irradiation

Energy Technology Data Exchange (ETDEWEB)

Ramazani, S.A. Ahmad, E-mail: Ramazani@sharif.ir [Polymer Group, Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Mousavi, Seyyed Abbas, E-mail: Musavi@che.sharif.ir [Department of Chemistry, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Seyedjafari, Ehsan [Department of Biotechnology, University College of Science, University of Tehran (Iran, Islamic Republic of); Poursalehi, Reza [Department of Physics, University of Shahed, Tehran (Iran, Islamic Republic of); Sareh, Shohreh [Research Center of Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Silakhori, Kaveh [Laser Research Center, Atomic Energy Organization, Tehran (Iran, Islamic Republic of); Poorfatollah, Ali Akbar [Research Center of Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Shamkhali, Amir Nasser [Department of Chemistry, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

2009-05-05

Nd:YAG laser treatment was used in order to increase surface cell adhesion aspects of polycarbonate (PC) films prepared via melt process. The treatment was carried out under different wavelengths and beam diameters. ATR-FTIR and UV spectra obtained from different samples before and after laser treatment in air showed that laser irradiation has induced some chemical and physical changes in surface properties. The irradiated films were also characterized using scanning electron microscopy (SEM) and contact angle measurements. Effect of pulse numbers on the surface properties was also investigated. Cell culture test was used to evaluate cell adhesion property on the PC films before and after treatment. The results obtained from this test showed that after laser treatment, the cells were attached and proliferated extensively on the Nd:YAG laser treated films in comparison with the unmodified PC. Moreover, it was revealed that a decrease in the laser beam diameter and an increase in the irradiated pulse numbers increased surface wettability and caused a better cell attachment on the polymer surface. The obtained results also showed that a decrease in the laser beam diameter and an increase in the irradiated pulse numbers increased surface wettability and caused a better cell attachment on the polymer surface.

Direct-to-consumer advertising of predictive genetic tests: a health belief model based examination of consumer response.

Science.gov (United States)

Rollins, Brent L; Ramakrishnan, Shravanan; Perri, Matthew

2014-01-01

Direct-to-consumer (DTC) advertising of predictive genetic tests (PGTs) has added a new dimension to health advertising. This study used an online survey based on the health belief model framework to examine and more fully understand consumers' responses and behavioral intentions in response to a PGT DTC advertisement. Overall, consumers reported moderate intentions to talk with their doctor and seek more information about PGTs after advertisement exposure, though consumers did not seem ready to take the advertised test or engage in active information search. Those who perceived greater threat from the disease, however, had significantly greater behavioral intentions and information search behavior.

Examination process of a nuclear reactor fuel assembly and examination machine to bring the process into operation

International Nuclear Information System (INIS)

Delaroche, P.; Leseur, A.; Saglio, R.; Vaubert, Y.

1983-01-01

The machine to examine a fuel assembly of a nuclear reactor includes a support on which the assembly to be examined is placed, a source emitting waves, directed to the assembly to be examined, devices to examine the assembly to be examined that receive the emitted wave by the said source and that have been reflected by the assembly. The examination devices have an axis, this axis being directed to a mirror, this mirror being inclined in such a way that it reflects the waves reflected by the assembly to the examination devices, a radiation protection, to avoid the radiation emitted by the assembly, being diposed between the assembly and the examination devices [fr

Observational study of surface wind along a sloping surface over mountainous terrain during winter

Science.gov (United States)

Lee, Young-Hee; Lee, Gyuwon; Joo, Sangwon; Ahn, Kwang-Deuk

2018-03-01

The 2018 Winter Olympic and Paralympic Games will be held in Pyeongchang, Korea, during February and March. We examined the near surface winds and wind gusts along the sloping surface at two outdoor venues in Pyeongchang during February and March using surface wind data. The outdoor venues are located in a complex, mountainous terrain, and hence the near-surface winds form intricate patterns due to the interplay between large-scale and locally forced winds. During February and March, the dominant wind at the ridge level is westerly; however, a significant wind direction change is observed along the sloping surface at the venues. The winds on the sloping surface are also influenced by thermal forcing, showing increased upslope flow during daytime. When neutral air flows over the hill, the windward and leeward flows show a significantly different behavior. A higher correlation of the wind speed between upper- and lower-level stations is shown in the windward region compared with the leeward region. The strong synoptic wind, small width of the ridge, and steep leeward ridge slope angle provide favorable conditions for flow separation at the leeward foot of the ridge. The gust factor increases with decreasing surface elevation and is larger during daytime than nighttime. A significantly large gust factor is also observed in the leeward region.

The role of direct photolysis and indirect photochemistry in the environmental fate of ethylhexyl methoxy cinnamate (EHMC) in surface waters

International Nuclear Information System (INIS)

Vione, D.; Calza, P.; Galli, F.; Fabbri, D.; Santoro, V.; Medana, C.

2015-01-01

The aquatic environmental fate of ethylhexyl methoxy cinnamate (EHMC), one of the most used UVB filters worldwide, was studied by assessing its environmental persistence and photoinduced transformations. The role of direct and indirect photolysis was evaluated. Direct photolysis was shown to play a key role, and this process is expected to be the main attenuation route of EHMC in sunlit surface waters. In contrast, the reaction with ·OH radicals would be negligible and that with "3CDOM* would at most be a secondary process. The measurement of the quantum yield of direct photolysis and of the rate constants of reaction with photogenerated transient species (or, sometimes, the use of reasonable values for the latter) allowed the prediction of the EHMC half-life time in surface waters, by means of a validated photochemical model. The predicted EHMC lifetime is of the order of hours to a few days in fair-weather summertime, and the main factors controlling the EHMC phototransformation in sunlit surface waters would be the water depth and the dissolved organic carbon (DOC) content. The formation of transformation products (TPs) was followed as well via HPLC/HRMS. Three TPs were detected in the samples exposed to UVA radiation, while one additional TP was detected in the samples exposed to UVB radiation. The detected TPs comprised 4-methoxybenzaldehyde, a hydroxylated derivative and dimeric species. Through the use of heterogeneous photocatalysis with TiO_2, seven additional TPs were identified, most of them resulting from the further degradation of primary TPs formed through direct photolysis and that might be detected in aquatic systems as well. The photodegradation of EHMC in the presence of TiO_2 yielded more toxic TPs than the parent compound (as determined with the Vibrio fischeri Microtox assay). The increased toxicity is partially accounted for by the formation of 4-methoxybenzaldehyde. - Highlights: • Study of the photolytic and photocatalytic transformation

The role of direct photolysis and indirect photochemistry in the environmental fate of ethylhexyl methoxy cinnamate (EHMC) in surface waters

Energy Technology Data Exchange (ETDEWEB)

Vione, D. [Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino (Italy); Calza, P., E-mail: paola.calza@unito.it [Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino (Italy); Galli, F.; Fabbri, D. [Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino (Italy); Santoro, V.; Medana, C. [Department of Molecular Biotechnology and Health Sciences, University of Torino, via P. Giuria 5, 10125 Torino (Italy)

2015-12-15

The aquatic environmental fate of ethylhexyl methoxy cinnamate (EHMC), one of the most used UVB filters worldwide, was studied by assessing its environmental persistence and photoinduced transformations. The role of direct and indirect photolysis was evaluated. Direct photolysis was shown to play a key role, and this process is expected to be the main attenuation route of EHMC in sunlit surface waters. In contrast, the reaction with ·OH radicals would be negligible and that with {sup 3}CDOM* would at most be a secondary process. The measurement of the quantum yield of direct photolysis and of the rate constants of reaction with photogenerated transient species (or, sometimes, the use of reasonable values for the latter) allowed the prediction of the EHMC half-life time in surface waters, by means of a validated photochemical model. The predicted EHMC lifetime is of the order of hours to a few days in fair-weather summertime, and the main factors controlling the EHMC phototransformation in sunlit surface waters would be the water depth and the dissolved organic carbon (DOC) content. The formation of transformation products (TPs) was followed as well via HPLC/HRMS. Three TPs were detected in the samples exposed to UVA radiation, while one additional TP was detected in the samples exposed to UVB radiation. The detected TPs comprised 4-methoxybenzaldehyde, a hydroxylated derivative and dimeric species. Through the use of heterogeneous photocatalysis with TiO{sub 2}, seven additional TPs were identified, most of them resulting from the further degradation of primary TPs formed through direct photolysis and that might be detected in aquatic systems as well. The photodegradation of EHMC in the presence of TiO{sub 2} yielded more toxic TPs than the parent compound (as determined with the Vibrio fischeri Microtox assay). The increased toxicity is partially accounted for by the formation of 4-methoxybenzaldehyde. - Highlights: • Study of the photolytic and photocatalytic

Research on the Effects of Process Parameters on Surface Roughness in Wet-Activated Silicon Direct Bonding Base on Orthogonal Experiments

Directory of Open Access Journals (Sweden)

Lei NIE

2015-11-01

Full Text Available Surface roughness is a very important index in silicon direct bonding and it is affected by processing parameters in the wet-activated process. These parameters include the concentration of activation solution, holding time and treatment temperature. The effects of these parameters were investigated by means of orthogonal experiments. In order to analyze the wafer roughness more accurately, the bear ratio of the surface was used as the evaluation index. From the results of the experiments, it could be concluded that the concentration of the activation solution affected the roughness directly and the higher the concentration, the lower the roughness. Holding time did not affect the roughness as acutely as that of the concentration, but a reduced activation time decreased the roughness perceptibly. It was also discovered that the treatment temperature had a weak correlation with the surface roughness. Based on these conclusions, the parameters of concentration, temperature and holding time were optimized respectively as NH4OH:H2O2=1:1 (without water, 70 °C and 5 min. The results of bonding experiments proved the validity of the conclusions of orthogonal experiments.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9711

Composition, morphology and surface recombination rate of HCl-isopropanol treated and vacuum annealed InAs(1 1 1)A surfaces

Energy Technology Data Exchange (ETDEWEB)

Kesler, V.G., E-mail: kesler@isp.nsc.ru [Institute of Semiconductor Physics SB RAS, Lavrentiev av., 13, Novosibirsk 630090 (Russian Federation); Seleznev, V.A.; Kovchavtsev, A.P.; Guzev, A.A. [Institute of Semiconductor Physics SB RAS, Lavrentiev av., 13, Novosibirsk 630090 (Russian Federation)

2010-05-01

X-ray photoelectron spectroscopy and atomic force microscopy were used to examine the chemical composition and surface morphology of InAs(1 1 1)A surface chemically etched in isopropanol-hydrochloric acid solution (HCl-iPA) and subsequently annealed in vacuum in the temperature range 200-500 deg. C. Etching for 2-30 min resulted in the formation of 'pits' and 'hillocks' on the sample surface, respectively 1-2 nm deep and high, with lateral dimensions 50-100 nm. The observed local formations, whose density was up to 3 x 10{sup 8} cm{sup -2}, entirely vanished from the surface after the samples were vacuum-annealed at temperatures above 300 deg. C. Using a direct method, electron beam microanalysis, we have determined that the defects of the hillock type includes oxygen and excessive As, while the 'pits' proved to be identical in their chemical composition to InAs. Vacuum anneals were found to cause a decrease in As surface concentration relative to In on InAs surface, with a concomitant rise of surface recombination rate.

Composition, morphology and surface recombination rate of HCl-isopropanol treated and vacuum annealed InAs(1 1 1)A surfaces

Science.gov (United States)

Kesler, V. G.; Seleznev, V. A.; Kovchavtsev, A. P.; Guzev, A. A.

2010-05-01

X-ray photoelectron spectroscopy and atomic force microscopy were used to examine the chemical composition and surface morphology of InAs(1 1 1)A surface chemically etched in isopropanol-hydrochloric acid solution (HCl-iPA) and subsequently annealed in vacuum in the temperature range 200-500 °C. Etching for 2-30 min resulted in the formation of "pits" and "hillocks" on the sample surface, respectively 1-2 nm deep and high, with lateral dimensions 50-100 nm. The observed local formations, whose density was up to 3 × 10 8 cm -2, entirely vanished from the surface after the samples were vacuum-annealed at temperatures above 300 °C. Using a direct method, electron beam microanalysis, we have determined that the defects of the hillock type includes oxygen and excessive As, while the "pits" proved to be identical in their chemical composition to InAs. Vacuum anneals were found to cause a decrease in As surface concentration relative to In on InAs surface, with a concomitant rise of surface recombination rate.

Composition, morphology and surface recombination rate of HCl-isopropanol treated and vacuum annealed InAs(1 1 1)A surfaces

International Nuclear Information System (INIS)

Kesler, V.G.; Seleznev, V.A.; Kovchavtsev, A.P.; Guzev, A.A.

2010-01-01

X-ray photoelectron spectroscopy and atomic force microscopy were used to examine the chemical composition and surface morphology of InAs(1 1 1)A surface chemically etched in isopropanol-hydrochloric acid solution (HCl-iPA) and subsequently annealed in vacuum in the temperature range 200-500 deg. C. Etching for 2-30 min resulted in the formation of 'pits' and 'hillocks' on the sample surface, respectively 1-2 nm deep and high, with lateral dimensions 50-100 nm. The observed local formations, whose density was up to 3 x 10 8 cm -2 , entirely vanished from the surface after the samples were vacuum-annealed at temperatures above 300 deg. C. Using a direct method, electron beam microanalysis, we have determined that the defects of the hillock type includes oxygen and excessive As, while the 'pits' proved to be identical in their chemical composition to InAs. Vacuum anneals were found to cause a decrease in As surface concentration relative to In on InAs surface, with a concomitant rise of surface recombination rate.

Direct observation of asperity deformation of specimens with random rough surfaces in upsetting and indentation processes

DEFF Research Database (Denmark)

Azushima, A.; Kuba, S.; Tani, S.

2006-01-01

The trapping behavior of liquid lubricant and contact behavior of asperities at the workpiece-tool interface during upsetting and indentation are observed directly using a compression subpress which consists of a transparent die made of sapphire, a microscope with a CCD camera and a video system....... The experiments are carried out without lubricant and with lubricant. Specimens used are commercially pure A1100 aluminum with a random rough surface. From these observations, the change in the fraction of real contact area is measured by an image processor. The real contact area ratios in upsetting experiments...

CFD simulation of direct contact condensation with ANSYS CFX using surface renewal theory based heat transfer coefficients

Energy Technology Data Exchange (ETDEWEB)

Wanninger, Andreas; Ceuca, Sabin Cristian; Macian-Juan, Rafael [Technische Univ. Muenchen, Garching (Germany). Dept. of Nuclear Engineering

2013-07-01

Different approaches for the calculation of Direct Contact Condensation (DCC) using Heat Transfer Coefficients (HTC) based on the Surface Renewal Theory (SRT) are tested using the CFD simulation tool ANSYS CFX. The present work constitutes a preliminary study of the flow patterns and conditions observed using different HTC models. A complex 3D flow pattern will be observed in the CFD simulations as well as a strong coupling between the condensation rate and the two-phase flow dynamics. (orig.)

Development of a biosensor microarray towards food screening using imaging surface plasmon resonance

NARCIS (Netherlands)

Rebe, S.; Bremer, M.G.E.G.; Giesbers, M.; Norde, W.

2008-01-01

In this study we examined the possibilities of implementing direct and competitive immunoassay formats for small and large molecule detection on a microarray, using IBIS imaging surface plasmon resonance (iSPR) system. First, IBIS iSPR optics performance was evaluated. Using a glycerol calibration

Development of a biosensor microarray towards food screening, using imaging surface plasmon resonance

NARCIS (Netherlands)

Raz, Sabina Rebe; Bremer, Maria G. E. G.; Giesbers, Marcel; Norde, Willem

2008-01-01

In this study we examined the possibilities of implementing direct and competitive immunoassay formats for small and large molecule detection on a microarray, using IBIS imaging surface plasmon resonance (iSPR) system. First, IBIS iSPR optics performance was evaluated. Using a glycerol calibration

The cardiovascular in-training examination: development, implementation, results, and future directions.

Science.gov (United States)

Kuvin, Jeffrey T; Soto, Amanda; Foster, Lauren; Dent, John; Kates, Andrew M; Polk, Donna M; Rosenzweig, Barry; Indik, Julia

2015-03-31

The American College of Cardiology (ACC), in collaboration with the National Board of Medical Examiners (NBME), developed the first standardized in-training examination (ITE) for cardiovascular disease fellows-in-training (FITs). In addition to testing knowledge, this examination uses the newly developed ACC Curricular Milestones to provide specific, competency-based feedback to program directors and FITs. The ACC ITE has been administered more than 5,000 times since 2011. This analysis sought to report the initial experience with the ITE, including feasibility and reliability of test development and implementation, as well as the ability of this process to provide useful feedback in key content areas. The annual ACC ITE has been available to cardiovascular disease fellowship programs in the United States since 2011. Questions for this Web-based, secure, multiple-choice examination were developed by a group of cardiovascular disease specialists and each question was analyzed by the NBME to ensure quality. Scores were equated and standardized to allow for comparability. Trainees and program directors were provided detailed feedback, including a list of the curricular competencies tested by those questions answered incorrectly. The ITE was administered 5,118 times. In 2013, the examination was taken by 1,969 fellows, representing 194 training programs. Among the 3 training years, there was consistency in the examination scores. Total test scores and scores within each of the content areas increased with each FIT year (there was a statistically significant difference in each cohort's average scale score across administration years). There was also significant improvement in examination scores across the fellowship years. The ACC ITE is a powerful tool available to all training programs to assess medical knowledge. This examination also delivers robust and timely feedback addressing individual knowledge gaps, and thus, may serve as a basis for improving training

Bi-directional Reflectance of Icy Surface Analogs: A Dual Approach

Science.gov (United States)

Quinones, Juan Manuel; Vides, Christina; Nelson, Robert M.; Boryta, Mark; Mannat, Ken s.

2018-01-01

Bi-directional reflectance measurements of analogs for planetary regolith have provided insight into the surface properties of planetary satellites and small bodies. Because Aluminum Oxide (Al2O3) and water ice share a similar hexagonal crystalline structure, the former has been used in laboratory experiments to simulate the regolith of both icy and dusty planetary bodies. By measuring various sizes of well sorted size fractions of Al2O3, the reflectance phase curve and porosity of a planetary regolith can be determined. We have designed an experiment to test the laboratory measurements produced by Nelson et al. (2000). Additionally, we made reflectance measurements for other alkali-halide compounds that could be used for applications beyond astronomy and planetary science.In order to provide an independent check on the Nelson et al. data, we designed an instrument with a different configuration. While both instruments take bidirectional reflectance measurements, our instrument, the Rigid Photometric Goniometer (RPG), is fixed at a phase angle of 5° and detects the scattered light with a photomultiplier tube (PMT). The PMT current is then measured with an electrometer. Following the example of Nelson et al., we measured the bidirectional reflectance of Al2O3 particulate size fractions between 0.1sizes from 20size that provided optimal, or maximum, reflectance for each compound. Our conclusions bring confirmation and clarity to photometric sciences.

The role of direct photolysis and indirect photochemistry in the environmental fate of ethylhexyl methoxy cinnamate (EHMC) in surface waters.

Science.gov (United States)

Vione, D; Calza, P; Galli, F; Fabbri, D; Santoro, V; Medana, C

2015-12-15

The aquatic environmental fate of ethylhexyl methoxy cinnamate (EHMC), one of the most used UVB filters worldwide, was studied by assessing its environmental persistence and photoinduced transformations. The role of direct and indirect photolysis was evaluated. Direct photolysis was shown to play a key role, and this process is expected to be the main attenuation route of EHMC in sunlit surface waters. In contrast, the reaction with OH radicals would be negligible and that with (3)CDOM* would at most be a secondary process. The measurement of the quantum yield of direct photolysis and of the rate constants of reaction with photogenerated transient species (or, sometimes, the use of reasonable values for the latter) allowed the prediction of the EHMC half-life time in surface waters, by means of a validated photochemical model. The predicted EHMC lifetime is of the order of hours to a few days in fair-weather summertime, and the main factors controlling the EHMC phototransformation in sunlit surface waters would be the water depth and the dissolved organic carbon (DOC) content. The formation of transformation products (TPs) was followed as well via HPLC/HRMS. Three TPs were detected in the samples exposed to UVA radiation, while one additional TP was detected in the samples exposed to UVB radiation. The detected TPs comprised 4-methoxybenzaldehyde, a hydroxylated derivative and dimeric species. Through the use of heterogeneous photocatalysis with TiO2, seven additional TPs were identified, most of them resulting from the further degradation of primary TPs formed through direct photolysis and that might be detected in aquatic systems as well. The photodegradation of EHMC in the presence of TiO2 yielded more toxic TPs than the parent compound (as determined with the Vibrio fischeri Microtox assay). The increased toxicity is partially accounted for by the formation of 4-methoxybenzaldehyde. Copyright © 2015 Elsevier B.V. All rights reserved.

Directional couplers using long-range surface plasmon polariton waveguides

DEFF Research Database (Denmark)

Boltasseva, Alexandra; Bozhevolnyi, Sergey I.

2006-01-01

14-nm-thick stripes and a wavelength of 1550 urn, LR-SPP propagation loss is determined for the stripe widths varying from 2 to 12 mu m and is found to be similar to 7 and 5 dB/cm for 10- and 4-mu m-wide stripes, respectively. For the directional couplers based on 14-nm-thick and 8-mu m-wide gold...... stripes and a wavelength of 1570 nm, the coupling lengths of 4.1, 1.9, and 0.8 mm are found for the respective waveguide separations of 8, 4, and 0 mu m. We model the LR-SPP-based directional couplers using the effective-refractive-index method and obtain a good agreement with the experimental results....... The transmission spectra of LR-SPP-based directional couplers are presented demonstrating an efficient (similar to 30 dB) separation of different telecom wavelength bands. Various possibilities for dynamic control of wavelength division/multiplexing with LRSPP-based directional couplers that utilize the thermo...

Atomic layer deposition of ruthenium surface-coating on porous platinum catalysts for high-performance direct ethanol solid oxide fuel cells

Science.gov (United States)

Jeong, Heon Jae; Kim, Jun Woo; Jang, Dong Young; Shim, Joon Hyung

2015-09-01

Pt-Ru bi-metallic catalysts are synthesized by atomic layer deposition (ALD) of Ru surface-coating on sputtered Pt mesh. The catalysts are evaluated in direct ethanol solid oxide fuel cells (DESOFCs) in the temperature range of 300-500 °C. Island-growth of the ALD Ru coating is confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy (XPS) analyses. The performance of the DESOFCs is evaluated based on the current-voltage output and electrochemical impedance spectroscopy. Genuine reduction of the polarization impedance, and enhanced power output with improved surface kinetics are achieved with the optimized ALD Ru surface-coating compared to bare Pt. The chemical composition of the Pt/ALD Ru electrode surface after fuel cell operation is analyzed via XPS. Enhanced cell performance is clearly achieved, attributed to the effective Pt/ALD Ru bi-metallic catalysis, including oxidation of Cdbnd O by Ru, and de-protonation of ethanol and cleavage of C-C bonds by Pt, as supported by surface morphology analysis which confirms formation of a large amount of carbon on bare Pt after the ethanol-fuel-cell test.

Direct surface analysis coupled to high-resolution mass spectrometry reveals heterogeneous composition of the cuticle of Hibiscus trionum petals.

Science.gov (United States)

Giorio, Chiara; Moyroud, Edwige; Glover, Beverley J; Skelton, Paul C; Kalberer, Markus

2015-10-06

Plant cuticle, which is the outermost layer covering the aerial parts of all plants including petals and leaves, can present a wide range of patterns that, combined with cell shape, can generate unique physical, mechanical, or optical properties. For example, arrays of regularly spaced nanoridges have been found on the dark (anthocyanin-rich) portion at the base of the petals of Hibiscus trionum. Those ridges act as a diffraction grating, producing an iridescent effect. Because the surface of the distal white region of the petals is smooth and noniridescent, a selective chemical characterization of the surface of the petals on different portions (i.e., ridged vs smooth) is needed to understand whether distinct cuticular patterns correlate with distinct chemical compositions of the cuticle. In the present study, a rapid screening method has been developed for the direct surface analysis of Hibiscus trionum petals using liquid extraction surface analysis (LESA) coupled with high-resolution mass spectrometry. The optimized method was used to characterize a wide range of plant metabolites and cuticle monomers on the upper (adaxial) surface of the petals on both the white/smooth and anthocyanic/ridged regions, and on the lower (abaxial) surface, which is entirely smooth. The main components detected on the surface of the petals are low-molecular-weight organic acids, sugars, and flavonoids. The ridged portion on the upper surface of the petal is enriched in long-chain fatty acids, which are constituents of the wax fraction of the cuticle. These compounds were not detected on the white/smooth region of the upper petal surface or on the smooth lower surface.

Direct quantification of negatively charged functional groups on membrane surfaces

KAUST Repository

Tiraferri, Alberto; Elimelech, Menachem

2012-01-01

groups at the surface of dense polymeric membranes. Both techniques consist of associating the membrane surface moieties with chemical probes, followed by quantification of the bound probes. Uranyl acetate and toluidine blue O dye, which interact

Deep Coherent Vortices and Their Sea Surface Expressions

Science.gov (United States)

Ienna, Federico; Bashmachnikov, Igor; Dias, Joaquim; Peliz, Alvaro

2017-04-01

Mediterranean Water eddies, known as Meddies, are an important dynamic process occurring at depths of 1000-meters in the Northeast Atlantic Ocean. Meddies occur as a direct result of the Mediterranean Outflow exiting through the Gibraltar Strait, and represent a prevalent mechanism that can be found extensively throughout the ocean. Moreover, Meddy cores are known to produce measurable expressions at the sea surface in the form of rotating coherent vortices, not only affecting the sea surface from beneath, but also allowing for the possibility to remotely study these deep phenomena through data gathered at the sea surface. While many past studies have focused on the properties of Meddy cores, only a handful of studies focus on the physical characteristics and behavior of the surface expressions produced. Are Meddy surface expressions different from other like vortices that dominate the physical ocean surface? What are the relationships between deep and surface mechanisms, and do any feedbacks exist? To shed light on these questions, we investigate the relationship between Meddies and their sea-surface expressions through observations using in-situ float and drifter profiles and satellite altimetry. A total of 782 Meddy cores were examined in the Northeast Atlantic using temperature and salinity data obtained by CTD and Argo during the Mecanismos de transporte e de dispersão da Água Mediterrânica no Atlântico Nordeste (MEDTRANS) project, and their corresponding sea-level expressions were geo-temporally matched in satellite altimetry data. We report several statistical properties of the sea-surface expressions of Meddies, including their mean diameter and vertical magnitude, and compare the properties of their surface features to the underlying Meddy cores. We investigate how the deep core affects the surface, and whether surface expressions may in return yield information about the underlying cores. Additionally, we examine the variability of the surface

Direct monophasic replacement of fatty acid by DMSA on SPION surface

Energy Technology Data Exchange (ETDEWEB)

Gogoi, M. [Department of Physics, Tezpur University (Central University), Tezpur 784028 (India); Deb, P., E-mail: pdeb@tezu.ernet.in [Department of Physics, Tezpur University (Central University), Tezpur 784028 (India); Interface Chemistry and Surface Engineering, Max-Planck-Institut fuer Eisenforschung GmbH, Max-Planck-Strasse 1, 40237 Duesseldorf (Germany); Vasan, G.; Keil, P.; Kostka, A.; Erbe, A. [Interface Chemistry and Surface Engineering, Max-Planck-Institut fuer Eisenforschung GmbH, Max-Planck-Strasse 1, 40237 Duesseldorf (Germany)

2012-10-01

Highlights: Black-Right-Pointing-Pointer Monophasic replacement of fatty acid coating. Black-Right-Pointing-Pointer Ultrastable dispersion of hydrophilic SPION in a wide pH range. Black-Right-Pointing-Pointer Unaltered microstructure and property on surface modification. - Abstract: Tailoring the surface and understanding the surface characteristics is necessary for biomedical applications of superparamagnetic nanoparticles. In this paper, superparamagnetic iron oxide nanoparticles (SPIONs) were prepared by thermal decomposition of iron nitrate in presence of stearic acid as surfactant. Due to the multilayer organization of surfactant molecules over the nanoparticle surface, the surface potential can be tuned by pH changes and hence the nanoparticles can be made dispersible in nonpolar as well as in polar solvents. We have presented a simple, facile procedure for controlled replacement of stearic acid from maghemite surface and subsequent derivatization by biocompatible dimercaptosuccinic acid (DMSA) to obtain ultrastable hydrophilic nanoparticles with unaltered morphology, phase and properties. The surface chemistry of the functionalized SPIONs was analyzed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) revealing the presence of bound and unbound thiol groups and disulfides, leading to its prolonged stability in aqueous medium. The consequence of spatially selective functionalization on the stability and solubility of surface hydrophilic SPION has also been realized.

Experimental study of surface quality and damage when drilling unidirectional CFRP composites

Directory of Open Access Journals (Sweden)

Eshetu D. Eneyew

2014-10-01

Full Text Available In this study, an experimental investigation on the drilling of unidirectional carbon fiber reinforced plastic (UD-CFRP composite was conducted using polycrystalline diamond (PCD tipped eight facet drill. The quality of the drilled hole surface was examined through surface roughness measurements and surface damage by scanning electron microscopy (SEM. It was found that fiber pullout occurred in two specific sectors relative to the angle between the cutting direction and the fiber orientation. The thrust force was highly influenced by the feed rate than the cutting speed and it shows a significant variation throughout the rotation of the drill.

Standard examination stage for the fuels and materials examination facility

International Nuclear Information System (INIS)

Hess, J.W.; Frandsen, G.B.

1980-01-01

A Standard Examination Stage (SES) has been designed, fabricated, and tested for use in the Fuel and Materials Examination Facility (FMEF) at the Hanford Reservation near Richland, WA. The SES will perform multiple functions in a variety of nuclear fuel, absorber, and blanket pin handling, positioning, and examination operations in 11 of 22 work stations in the FMEF Nondestructive Examination (NDE) cell. Preprogrammable, automated, closed loop computer control provides precision positioning in the X, Y and Z directions and in pin rotational positioning. Modular construction of both the mechanical hardware and the electrical and control system has been used to facilitate in-cell maintainability

Bacterial resistance of self-assembled surfaces using PPOm-b-PSBMAn zwitterionic copolymer - concomitant effects of surface topography and surface chemistry on attachment of live bacteria.

Science.gov (United States)

Hsiao, Sheng-Wen; Venault, Antoine; Yang, Hui-Shan; Chang, Yung

2014-06-01

Three well-defined diblock copolymers made of poly(sulfobetaine methacrylate) (poly(SBMA)) and poly(propylene oxide) (PPO) groups were synthesized by atom transfer radical polymerization (ATRP) method. They were physically adsorbed onto three types of surfaces having different topography, including smooth flat surface, convex surface, and indented surface. Chemical state of surfaces was characterized by XPS while the various topographies were examined by SEM and AFM. Hydrophilicity of surfaces was dependent on both the surface chemistry and the surface topography, suggesting that orientation of copolymer brushes can be tuned in the design of surfaces aimed at resisting bacterial attachment. Escherichia coli, Staphylococcus epidermidis, Streptococcus mutans and Escherichia coli with green fluorescent protein (E. coli GFP) were used in bacterial tests to assess the resistance to bacterial attachment of poly(SBMA)-covered surfaces. Results highlighted a drastic improvement of resistance to bacterial adhesion with the increasing of poly(SBMA) to PPO ratio, as well as an important effect of surface topography. The chemical effect was directly related to the length of the hydrophilic moieties. When longer, more water could be entrapped, leading to improved anti-bacterial properties. The physical effect impacted on the orientation of the copolymer brushes, as well as on the surface contact area available. Convex surfaces as well as indented surfaces wafer presented the best resistance to bacterial adhesion. Indeed, bacterial attachment was more importantly reduced on these surfaces compared with smooth surfaces. It was explained by the non-orthogonal orientation of copolymer brushes, resulting in a more efficient surface coverage of zwitterionic molecules. This work suggests that not only the control of surface chemistry is essential in the preparation of surfaces resisting bacterial attachment, but also the control of surface topography and orientation of antifouling

Return polynomials for non-intersecting paths above a surface on the directed square lattice

Energy Technology Data Exchange (ETDEWEB)

Brak, R. [Deartment of Mathematics, University of Melbourne, Parkville, VIC (Australia)]. E-mail: r.brak@ms.unimelb.edu.au; Essam, J.W. [Department of Mathematics, Royal Holloway College, University of London, Egham, Surrey (United Kingdom)]. E-mail: j.essam@alpha1.rhul.ac.uk

2001-12-14

We enumerate sets of n non-intersecting, t-step paths on the directed square lattice which are excluded from the region below the surface y=0 to which they are initially attached. In particular we obtain a product formula for the number of star configurations in which the paths have arbitrary fixed endpoints. We also consider the 'return' polynomial, R-'{sup W}{sub t}(y;k)={sigma}{sub m{>=}}{sub 0}r-'{sup W}{sub t}(y;m)k{sup m} where r-'{sup W}{sub t}(y;m) is the number of n-path configurations of watermelon type having deviation {gamma} for which the path closest to the surface returns to the surface m times. The 'marked return' polynomial is defined by u-'{sup W}{sub t}(y;k{sub 1}){identical_to}R-'{sup W}{sub 1}(y;k{sub 1}+l)={sigma}{sub m{>=}}{sub 0}u-'{sup W}{sub t}(y;m)k{sub 1}{sup m} where u-'{sup W}{sub t}(y;m) is the number of marked configurations having at least m returns, just m of which are marked. Both r-'{sup W}{sub t}(y;m) and u-'{sup W}(y;m) are expressed in terms of the numbers of paths ignoring returns but introducing a suitably modified endpoint condition. This enables u-'{sup W}{sub t}(y;m) to be written in product form for arbitrary y, but for r-'{sup W}{sub t}(y;m) this can only be done in the case y=0. (author)

Direct formation of gold nanorods on surfaces using polymer-immobilised gold seeds

Directory of Open Access Journals (Sweden)

Majid K. Abyaneh

2016-06-01

Full Text Available Herein, we present the formation of gold nanorods (GNRs on novel gold–poly(methyl methacrylate (Au–PMMA nanocomposite substrates with unprecedented growth control through the polymer molecular weight (Mw and gold-salt-to-polymer weight ratio. For the first time, GNRs have been produced by seed-mediated direct growth on surfaces that were pre-coated with polymer-immobilised gold seeds. A Au–PMMA nanocomposite formed by UV photoreduction has been used as the gold seed. The influence of polymer Mw and gold concentration on the formation of GNRs has been investigated and discussed. The polymer nanocomposite formed with a lower Mw PMMA and 20 wt % gold salt provides a suitable medium for growing well-dispersed GNRs. In this sample, the average dimension of produced GNRs is 200 nm in length with aspect ratios up to 10 and a distribution of GNRs to nanoparticles of nearly 22%. Suitable characterization techniques such as AFM and SEM have been used to support concept of the proposed growth method.

Direct quantification of negatively charged functional groups on membrane surfaces

KAUST Repository

Tiraferri, Alberto

2012-02-01

Surface charge plays an important role in membrane-based separations of particulates, macromolecules, and dissolved ionic species. In this study, we present two experimental methods to determine the concentration of negatively charged functional groups at the surface of dense polymeric membranes. Both techniques consist of associating the membrane surface moieties with chemical probes, followed by quantification of the bound probes. Uranyl acetate and toluidine blue O dye, which interact with the membrane functional groups via complexation and electrostatic interaction, respectively, were used as probes. The amount of associated probes was quantified using liquid scintillation counting for uranium atoms and visible light spectroscopy for the toluidine blue dye. The techniques were validated using self-assembled monolayers of alkanethiols with known amounts of charged moieties. The surface density of negatively charged functional groups of hand-cast thin-film composite polyamide membranes, as well as commercial cellulose triacetate and polyamide membranes, was quantified under various conditions. Using both techniques, we measured a negatively charged functional group density of 20-30nm -2 for the hand-cast thin-film composite membranes. The ionization behavior of the membrane functional groups, determined from measurements with toluidine blue at varying pH, was consistent with published data for thin-film composite polyamide membranes. Similarly, the measured charge densities on commercial membranes were in general agreement with previous investigations. The relative simplicity of the two methods makes them a useful tool for quantifying the surface charge concentration of a variety of surfaces, including separation membranes. © 2011 Elsevier B.V.

In vitro performance of DIAGNOdent laser fluorescence device for dental calculus detection on human tooth root surfaces

Directory of Open Access Journals (Sweden)

Thomas E. Rams

2017-10-01

Conclusions: Excellent intra- and inter-examiner reproducibility of autofluorescence intensity measurements was obtained with the DIAGNOdent laser fluorescence device on human tooth roots. Calculus-positive root surfaces exhibited significantly greater DIAGNOdent laser autofluorescence than calculus-free tooth roots, even with the laser probe tip directed parallel to root surfaces. These findings provide further in vitro validation of the potential utility of a DIAGNOdent laser fluorescence device for identifying dental calculus on human tooth root surfaces.

Near Surface Geophysical Investigations of Potential Direct Recharge Zones in the Biscayne Aquifer within Everglades National Park, Florida.

Science.gov (United States)

Mount, G.; Comas, X.

2017-12-01

The karstic Miami Limestone of the Biscayne aquifer is characterized as having water flow that is controlled by the presence of dissolution enhanced porosity and mega-porous features. The dissolution features and other high porosity areas create horizontal preferential flow paths and high rates of ground water velocity, which may not be accurately conceptualized in groundwater flow models. In addition, recent research suggests the presence of numerous vertical dissolution features across Everglades National Park at Long Pine Key Trail, that may act as areas of direct recharge to the aquifer. These vertical features have been identified through ground penetrating radar (GPR) surveys as areas of velocity pull-down which have been modeled to have porosity values higher than the surrounding Miami Limestone. As climate change may induce larger and longer temporal variability between wet and dry times in the Everglades, a more comprehensive understanding of preferential flow pathways from the surface to the aquifer would be a great benefit to modelers and planners. This research utilizes near surface geophysical techniques, such as GPR, to identify these vertical dissolution features and then estimate the spatial variability of porosity using petrophysical models. GPR transects that were collected for several kilometers along the Long Pine Key Trail, show numerous pull down areas that correspond to dissolution enhanced porosity zones within the Miami Limestone. Additional 3D GPR surveys have attempted to delineate the boundaries of these features to elucidate their geometry for future modelling studies. We demonstrate the ability of near surface geophysics and petrophysical models to identify dissolution enhanced porosity in shallow karstic limestones to better understand areas that may act as zones of direct recharge into the Biscayne Aquifer.

Separation followed by direct SERS detection of explosives on a novel black silicon multifunctional nanostructured surface prepared in a microfluidic channel

DEFF Research Database (Denmark)

Talian, Ivan; Hübner, Jörg

2013-01-01

The article describes the multifunctionality of a novel black silicon (BS) nanostructured surface covered with a thin layer of noble metal prepared in the a microfluidic channel. It is focused on the separation properties of the BS substrate with direct detection of the separated analytes utilizing...

Direct numerical simulations of a thin liquid film coating an axially oscillating cylindrical surface

Energy Technology Data Exchange (ETDEWEB)

Binz, Matthias; Rohlfs, Wilko; Kneer, Reinhold, E-mail: rohlfs@wsa.rwth-aachen.de [Institute of Heat and Mass Transfer, RWTH Aachen University, Augustinerbach 6, D-52056 Aachen (Germany)

2014-08-01

Liquid films on cylindrical bodies like wires or fibers disintegrate into droplets if their length exceeds a critical measure (Plateau–Rayleigh instability). Stabilization of such films can be achieved by an axial oscillation of the solid core provided that a suitable combination of forcing amplitude and frequency is given. To investigate the stabilizing effect, direct numerical simulations of the axisymmetric problem are conducted in this study. Thus, a modified volume-of-fluid solver is employed based on the open source library OpenFOAM{sup ®}. The effect of film stabilization is demonstrated and the required conditions for a stable film configuration are found to be in accordance with other studies. Finally, parameter variations are conducted to investigate the influence on the long-term shape of the stabilized film surface. (paper)

High Surface Area of Porous Silicon Drives Desorption of Intact Molecules

Science.gov (United States)

Northen, Trent R.; Woo, Hin-Koon; Northen, Michael T.; Nordström, Anders; Uritboonthail, Winnie; Turner, Kimberly L.; Siuzdak, Gary

2007-01-01

The surface structure of porous silicon used in desorption/ionization on porous silicon (DIOS) mass analysis is known to play a primary role in the desorption/ionization (D/I) process. In this study, mass spectrometry and scanning electron microscopy (SEM) are used to examine the correlation between intact ion generation with surface ablation, and surface morphology. The DIOS process is found to be highly laser energy dependent and correlates directly with the appearance of surface ions (Sin+ and OSiH+). A threshold laser energy for DIOS is observed (10 mJ/cm2), which supports that DIOS is driven by surface restructuring and is not a strictly thermal process. In addition, three DIOS regimes are observed which correspond to surface restructuring and melting. These results suggest that higher surface area silicon substrates may enhance DIOS performance. A recent example which fits into this mechanism is silicon nanowires surface which have a high surface energy and concomitantly requires lower laser energy for analyte desorpton. PMID:17881245

Surface energy and surface stress on vicinals by revisiting the Shuttleworth relation

Science.gov (United States)

Hecquet, Pascal

2018-04-01

In 1998 [Surf. Sci. 412/413, 639 (1998)], we showed that the step stress on vicinals varies as 1/L, L being the distance between steps, while the inter-step interaction energy primarily follows the law as 1/L2 from the well-known Marchenko-Parshin model. In this paper, we give a better understanding of the interaction term of the step stress. The step stress is calculated with respect to the nominal surface stress. Consequently, we calculate the diagonal surface stresses in both the vicinal system (x, y, z) where z is normal to the vicinal and the projected system (x, b, c) where b is normal to the nominal terrace. Moreover, we calculate the surface stresses by using two methods: the first called the 'Zero' method, from the surface pressure forces and the second called the 'One' method, by homogeneously deforming the vicinal in the parallel direction, x or y, and by calculating the surface energy excess proportional to the deformation. By using the 'One' method on the vicinal Cu(0 1 M), we find that the step deformations, due to the applied deformation, vary as 1/L by the same factor for the tensor directions bb and cb, and by twice the same factor for the parallel direction yy. Due to the vanishing of the surface stress normal to the vicinal, the variation of the step stress in the direction yy is better described by using only the step deformation in the same direction. We revisit the Shuttleworth formula, for while the variation of the step stress in the direction xx is the same between the two methods, the variation in the direction yy is higher by 76% for the 'Zero' method with respect to the 'One' method. In addition to the step energy, we confirm that the variation of the step stress must be taken into account for the understanding of the equilibrium of vicinals when they are not deformed.

Examining microbial community response to a strong chemical gradient: the effects of surface coal mining on stream bacteria

Science.gov (United States)

Bier, R.; Lindberg, T. T.; Wang, S.; Ellis, J. C.; Di Giulio, R. T.; Bernhardt, E. S.

2012-12-01

Surface coal mining is the dominant form of land cover change in northern and central Appalachia. In this process, shallow coal seams are exposed by removing overlying rock with explosives. The resulting fragmented carbonate rock and coal residues are disposed of in stream valleys. These valley fills generate alkaline mine drainage (AlkMD), dramatically increasing alkalinity, ionic strength, substrate supply (esp. SO42-), and trace element (Mn, Li, Se, U) concentrations in downstream rivers as well as significant losses of sensitive fish and macroinvertebrate species. In prior work within the Mud River, which drains the largest surface mine complex in Appalachia, we found that concentrations of AlkMD increase proportionally with the extent of upstream mining. Here we ask "How do stream microbial communities change along this strong chemical gradient?" We collected surface water and benthic biofilms from 25 stream reaches throughout the Mud River spanning the full range of surface mining impacts, with 0-96% of the contributing watershed area converted to surface coal mines. Microbial communities were collected from biofilms grown on a common substrate (red maple veneers) that were incubated in each stream reach for four months prior to collection in April, 2011. 16S rRNA genes from microbial communities at each study site were examined using 454 sequencing and compared with a generalized UniFrac distance matrix (674 sequence eveness) that was used in statistical analyses. Water chemistry at the sites was sampled monthly from July 2010 to December 2010 and again in April 2011. In April, surface water concentrations of SO42-, Ca2+, Mg2+, and Se2- increased linearly with the extent of upstream mining (all regressions R2 >0.43; pPERMANOVA; p=0.029). Bacterial diversity (OTU richness defined at 3% sequence difference) peaked at intermediate conductivities (600 μS cm-1). Environmental data that correlated significantly with the ordination axes were a variety of surface

34 CFR 101.79 - Cross-examination.

Science.gov (United States)

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false Cross-examination. 101.79 Section 101.79 Education...-examination. A witness may be cross-examined on any matter material to the proceeding without regard to the scope of his direct examination. ...

The role of surface charging during the coadsorption of mercaptohexanol to DNA layers on gold: direct observation of desorption and layer reorientation.

Science.gov (United States)

Arinaga, K; Rant, U; Tornow, M; Fujita, S; Abstreiter, G; Yokoyama, N

2006-06-20

We study the coadsorption of mercaptohexanol onto preimmobilized oligonucleotide layers on gold. Monitoring the position of the DNA relative to the surface by optical means directly shows the mercaptohexanol-induced desorption of DNA and the reorientation of surface-tethered strands in situ and in real time. By simultaneously recording the electrochemical electrode potential, we are able to demonstrate that changes in the layer conformation are predominantly of electrostatic origin and can be reversed by applying external bias to the substrate.

Elucidation of Peptide-Directed Palladium Surface Structure for Biologically Tunable Nanocatalysts

Energy Technology Data Exchange (ETDEWEB)

Bedford, Nicholas M.; Ramezani-Dakhel, Hadi; Slocik, Joseph M.; Briggs, Beverly D.; Ren, Yang; Frenkel, Anatoly I.; Petkov, Valeri; Heinz, Hendrik; Naik, Rajesh R.; Knecht, Mark R.

2015-05-01

Peptide-enabled synthesis of inorganic nanostructures represents an avenue to access catalytic materials with tunable and optimized properties. This is achieved via peptide complexity and programmability that is missing in traditional ligands for catalytic nanomaterials. Unfortunately, there is limited information available to correlate peptide sequence to particle structure and catalytic activity to date. As such, the application of peptide-enabled nanocatalysts remains limited to trial and error approaches. In this paper, a hybrid experimental and computational approach is introduced to systematically elucidate biomolecule-dependent structure/function relationships for peptide-capped Pd nanocatalysts. Synchrotron X-ray techniques were used to uncover substantial particle surface structural disorder, which was dependent upon the amino acid sequence of the peptide capping ligand. Nanocatalyst configurations were then determined directly from experimental data using reverse Monte Carlo methods and further refined using molecular dynamics simulation, obtaining thermodynamically stable peptide-Pd nanoparticle configurations. Sequence-dependent catalytic property differences for C-C coupling and olefin hydrogenation were then eluddated by identification of the catalytic active sites at the atomic level and quantitative prediction of relative reaction rates. This hybrid methodology provides a clear route to determine peptide-dependent structure/function relationships, enabling the generation of guidelines for catalyst design through rational tailoring of peptide sequences

Direct sulfation of limestone based on oxy-fuel combustion technology

Energy Technology Data Exchange (ETDEWEB)

Chen, C.M.; Zhao, C.S.; Liu, S.T.; Wang, C.B. [North China Electric Power University, Baoding (China)

2009-10-15

With limestone as the sorbent, the sulfation reaction can proceed via two different routes depending on whether calcination of the limestone takes place under the given reaction conditions. The direct sulfation reaction is defined as the sulfation reaction between sulfur dioxide (SO{sub 2}) and limestone in an uncalcined state. This reaction, based on oxyfuel combustion technology, was studied by thermogravimetric analysis. Surface morphologies of the limestone particles after sulfation were examined by a scanning electron microscope. Results show that there are more pores or gaps in the product layer formed by direct sulfation of limestone than by indirect sulfation, which can be attributed to the generation of carbon dioxide (CO{sub 2}) at a reaction interface. Compared with indirect sulfation, direct sulfation of limestone can yield much higher conversion and has a much higher reaction rate. For direct sulfation, the greater porosity in the product layer greatly reduces the solid-state ion diffusion distance, resulting in a higher reaction rate and higher conversion.

Laser-Aided Directed Energy Deposition of Steel Powder over Flat Surfaces and Edges.

Science.gov (United States)

Caiazzo, Fabrizia; Alfieri, Vittorio

2018-03-16

In the framework of Additive Manufacturing of metals, Directed Energy Deposition of steel powder over flat surfaces and edges has been investigated in this paper. The aims are the repair and overhaul of actual, worn-out, high price sensitive metal components. A full-factorial experimental plan has been arranged, the results have been discussed in terms of geometry, microhardness and thermal affection as functions of the main governing parameters, laser power, scanning speed and mass flow rate; dilution and catching efficiency have been evaluated as well to compare quality and effectiveness of the process under conditions of both flat and edge depositions. Convincing results are presented to give grounds for shifting the process to actual applications: namely, no cracks or pores have been found in random cross-sections of the samples in the processing window. Interestingly an effect of the scanning conditions has been proven on the resulting hardness in the fusion zone; therefore, the mechanical characteristics are expected to depend on the processing parameters.

Modeling large-scale human alteration of land surface hydrology and climate

Science.gov (United States)

Pokhrel, Yadu N.; Felfelani, Farshid; Shin, Sanghoon; Yamada, Tomohito J.; Satoh, Yusuke

2017-12-01

Rapidly expanding human activities have profoundly affected various biophysical and biogeochemical processes of the Earth system over a broad range of scales, and freshwater systems are now amongst the most extensively altered ecosystems. In this study, we examine the human-induced changes in land surface water and energy balances and the associated climate impacts using a coupled hydrological-climate model framework which also simulates the impacts of human activities on the water cycle. We present three sets of analyses using the results from two model versions—one with and the other without considering human activities; both versions are run in offline and coupled mode resulting in a series of four experiments in total. First, we examine climate and human-induced changes in regional water balance focusing on the widely debated issue of the desiccation of the Aral Sea in central Asia. Then, we discuss the changes in surface temperature as a result of changes in land surface energy balance due to irrigation over global and regional scales. Finally, we examine the global and regional climate impacts of increased atmospheric water vapor content due to irrigation. Results indicate that the direct anthropogenic alteration of river flow in the Aral Sea basin resulted in the loss of 510 km3 of water during the latter half of the twentieth century which explains about half of the total loss of water from the sea. Results of irrigation-induced changes in surface energy balance suggest a significant surface cooling of up to 3.3 K over 1° grids in highly irrigated areas but a negligible change in land surface temperature when averaged over sufficiently large global regions. Results from the coupled model indicate a substantial change in 2 m air temperature and outgoing longwave radiation due to irrigation, highlighting the non-local (regional and global) implications of irrigation. These results provide important insights on the direct human alteration of land surface

Data fusion analysis of a surface direct-current resistivity and well pick data set

International Nuclear Information System (INIS)

Clayton, E.A.; Lewis, R.E.

1995-09-01

Pacific Northwest Laboratory (PNL) has been tasked with testing, debugging, and refining the Hanford Site data fusion workstation (DFW), with the assistance of Coleman Research Corporation (CRC), before delivering the DFW to the environmental restoration client at the Hanford Site. Data fusion is the mathematical combination (or fusion) of disparate data sets into a single interpretation. The data fusion software used in this study was developed by CRC. This report discusses the results of evaluating a surface direct-current (dc) resistivity and well-pick data set using two methods: data fusion technology and commercially available software (i.e., RESIX Plus from Interpex Ltd., Golden, Colorado), the conventional method of analysis. The report compares the two technologies; describes the survey, procedures, and results; and includes conclusions and recommendations. The surface dc resistivity and well-pick data set had been acquired by PNL from a study performed in May 1993 at Eielson Air Force Base near Fairbanks, Alaska. The resistivity survey data were acquired to map the top of permafrost in support of a hydrogeologic study. This data set provided an excellent opportunity to test and refine the dc resistivity capabilities of the DFW; previously, the data fusion software was untested on dc resistivity data. The DFW was used to evaluate the dc resistivity survey data and to produce a 3-dimensional earth model of the study area

The place of surface anatomy in the medical literature and undergraduate anatomy textbooks.

Science.gov (United States)

Azer, Samy A

2013-01-01

The aims of this review were to examine the place of surface anatomy in the medical literature, particularly the methods and approaches used in teaching surface and living anatomy and assess commonly used anatomy textbooks in regard to their surface anatomy contents. PubMed and MEDLINE databases were searched using the following keywords "surface anatomy," "living anatomy," "teaching surface anatomy," "bony landmarks," "peer examination" and "dermatomes". The percentage of pages covering surface anatomy in each textbook was calculated as well as the number of images covering surface anatomy. Clarity, quality and adequacy of surface anatomy contents was also examined. The search identified 22 research papers addressing methods used in teaching surface anatomy, 31 papers that can help in the improvement of surface anatomy curriculum, and 12 anatomy textbooks. These teaching methods included: body painting, peer volunteer surface anatomy, use of a living anatomy model, real time ultrasound, virtual (visible) human dissector (VHD), full body digital x-ray of cadavers (Lodox(®) Statscan(®) images) combined with palpating landmarks on peers and the cadaver, as well as the use of collaborative, contextual and self-directed learning. Nineteen of these studies were published in the period from 2006 to 2013. The 31 papers covered evidence-based and clinically-applied surface anatomy. The percentage of surface anatomy in textbooks' contents ranged from 0 to 6.2 with an average of 3.4%. The number of medical illustrations on surface anatomy varied from 0 to 135. In conclusion, although there has been a progressive increase in publications addressing methods used in teaching surface anatomy over the last six to seven years, most anatomy textbooks do not provide students with adequate information about surface anatomy. Only three textbooks provided a solid explanation and foundation of understanding surface anatomy. © 2013 American Association of Anatomists.

A Metallurgical Investigation of the Direct Energy Deposition Surface Repair of Ferrous Alloys

Science.gov (United States)

Marya, Manuel; Singh, Virendra; Hascoet, Jean-Yves; Marya, Surendar

2018-02-01

Among additive manufacturing (AM) processes, the direct energy deposition (DED) by laser is explored to establish its applicability for the repair of ferrous alloys such as UNS G41400 low-alloy steel, UNS S41000 martensitic stainless steel, UNS S17400 precipitation-strengthened martensitic stainless steel, and UNS S32750 super-duplex stainless steel. Unlike plating, thermal spray, and conventional cladding weld, DED laser powder deposition offers potential advantages, e.g., thin deposits, limited dilutions, narrow heat-affected zones (HAZ), potentially improved surface properties. In this investigation, all AM deposits were completed with an IREPA CLAD™ system using a powder feed of UNS N06625, an alloy largely selected for its outstanding corrosion resistance. This investigation first addresses topological aspects of AM deposits (including visual imperfections) before focusing on changes in microstructure, microhardness, chemical composition across AM deposits and base materials. It has been established that dense, uniform, hard ( 300 HVN), crack-free UNS N06625-compliant AM deposits of fine dendritic microstructures are reliably produced. However, except for the UNS S32750 steel, a significant martensitic hardening was observed in the HAZs of UNS G41400 ( 650 HVN), UNS S41000 ( 500 HVN), and UNS S17400 ( 370 HVN). In summary, this investigation demonstrates that the DED laser repair of ferrous parts with UNS N06625 may restore damaged surfaces, but it also calls for cautions and complementary investigations for alloys experiencing a high HAZ hardening, for which industry standard recommendations are exceeded and lead to an increased risk of delayed cracking in corrosive environments.

QM/MM Geometry Optimization on Extensive Free-Energy Surfaces for Examination of Enzymatic Reactions and Design of Novel Functional Properties of Proteins.

Science.gov (United States)

Hayashi, Shigehiko; Uchida, Yoshihiro; Hasegawa, Taisuke; Higashi, Masahiro; Kosugi, Takahiro; Kamiya, Motoshi

2017-05-05

Many remarkable molecular functions of proteins use their characteristic global and slow conformational dynamics through coupling of local chemical states in reaction centers with global conformational changes of proteins. To theoretically examine the functional processes of proteins in atomic detail, a methodology of quantum mechanical/molecular mechanical (QM/MM) free-energy geometry optimization is introduced. In the methodology, a geometry optimization of a local reaction center is performed with a quantum mechanical calculation on a free-energy surface constructed with conformational samples of the surrounding protein environment obtained by a molecular dynamics simulation with a molecular mechanics force field. Geometry optimizations on extensive free-energy surfaces by a QM/MM reweighting free-energy self-consistent field method designed to be variationally consistent and computationally efficient have enabled examinations of the multiscale molecular coupling of local chemical states with global protein conformational changes in functional processes and analysis and design of protein mutants with novel functional properties.

Real-time measurement of plutonium in air by direct-inlet surface ionization mass spectrometry. Status report

International Nuclear Information System (INIS)

Stoffels, J.J.

1980-04-01

A new technique is being developed for monitoring low-level airborne plutonium on a real-time basis. The technique is based on surface ionization mass spectrometry of airborne particles. It will be capable of measuring plutonium concentrations below the maximum permissible concentration (MPC) level. A complete mass spectrometer was designed and constructed for this purpose. Major components which were developed and made operational for the instrument include an efficient inlet for directly sampling particles in air, a wide dynamic range ion detector and a minicomputer-based ion-burst measurement system. Calibration of the direct-inlet mass spectrometer (DIMS) was initiated to establish the instrument's response to plutonium dioxide as a function of concentration and particle size. This work revealed an important problem - bouncing of particles upon impact with the ionizing filament. Particle bounce results in a significant loss of measurement sensitivity. The feasibility of using an oven ionizer to overcome the particle bounce problem has been demonstrated. A rhenium oven ionizer was designed and constructed for the purpose of trapping particles which enter via the direct inlet. High-speed particles were trapped in the oven yielding a measurement sensitivity comparable to that for particles which are preloaded. Development of the Pu DIMS can now be completed by optimizing the oven design and calibrating the instrument's performance with UO 2 and CeO 2 particles as analogs to PuO 2 particles

Novel CNC Grinding Process Control for Nanometric Surface Roughness for Aspheric Space Optical Surfaces

Directory of Open Access Journals (Sweden)

Jeong-Yeol Han

2004-06-01

Full Text Available Optics fabrication process for precision space optical parts includes bound abrasive grinding, loose abrasive lapping and polishing. The traditional bound abrasive grinding with bronze bond cupped diamond wheel leaves the machine marks of about 20 μm rms in height and the subsurface damage of about 1 μm rms in height to be removed by subsequent loose abrasive lapping. We explored an efficient quantitative control of precision CNC grinding. The machining parameters such as grain size, work-piece rotation speed and feed rate were altered while grinding the work-piece surfaces of 20-100 mm in diameter. The input grinding variables and the resulting surface quality data were used to build grinding prediction models using empirical and multi-variable regression analysis. The effectiveness of such grinding prediction models was then examined by running a series of precision CNC grinding operation with a set of controlled input variables and predicted output surface quality indicators. The experiment achieved the predictability down to ±20 nm in height and the surface roughness down to 36 nm in height. This study contributed to improvement of the process efficiency reaching directly the polishing and figuring process without the need for the loose abrasive lapping stage.

Matlab Source Code for Species Transport through Nafion Membranes in Direct Ethanol, Direct Methanol, and Direct Glucose Fuel Cells

OpenAIRE

JH, Summerfield; MW, Manley

2016-01-01

A simple simulation of chemical species movement is presented. The species traverse a Nafion membrane in a fuel cell. Three cells are examined: direct methanol, direct ethanol, and direct glucose. The species are tracked using excess proton concentration, electric field strength, and voltage. The Matlab computer code is provided.

In vivo analysis of trapeziometacarpal joint arthrokinematics during multi-directional thumb motions.

Science.gov (United States)

Su, Fong-Chin; Lin, Chien-Ju; Wang, Chien-Kuo; Chen, Guan-Po; Sun, Yung-Nien; Chuang, Alan K; Kuo, Li-Chieh

2014-11-01

The investigation of the joint arthrokinematics of the trapeziometacarpal joint is critical to comprehend the causative mechanism underlying this common form of osteoarthritis. Therefore, the purpose of this study is to evaluate the arthrokinematics of the trapeziometacarpal joint during thumb postures in vivo. Fifteen healthy participants were enrolled in this study. Static computed tomography images of the 1st metacarpal bone and trapezium were taken at specific thumb postures during thumb flexion-extension, abduction-adduction, and circumduction motions. Images were analyzed to examine the joint gliding, expressed as displacement of the centroid of the articular surface of the 1st metacarpal bone, relative to the trapezium. The gliding ratio, defined as joint gliding in each direction normalized to the dimension of the trapezium joint surface in the given direction, was computed and compared between different thumb motions. The results indicate that thumb motions influenced joint gliding. The centroids of the articular surface of the 1st metacarpal bone were primarily located at the central and dorsal-radial regions while executing these motions. The maximum joint gliding of the 1st metacarpal bone occurred in the radial-ulnar direction when performing abduction-adduction, and in the dorsal-volar direction while performing flexion-extension and circumduction, with the gliding ratio values of 42.35%, 51.65%, and 51.85%, respectively. Activities that involved abduction-adduction in the trapeziometacarpal joint caused greater joint gliding in the ulnar-radial direction, while flexion-extension resulted in greater joint gliding in the dorsal-volar and distal-proximal directions. Understanding normal joint kinematics in vivo may provide insights into the possible mechanism leading to osteoarthritis of the trapeziometacarpal joint, and help to improve the design of implants. Copyright © 2014 Elsevier Ltd. All rights reserved.

An immunoassay for dibutyl phthalate based on direct hapten linkage to the polystyrene surface of microtiter plates.

Directory of Open Access Journals (Sweden)

Chenxi Wei

Full Text Available BACKGROUND: Dibutyl phthalate (DBP is predominantly used as a plasticizer inplastics to make them flexible. Extensive use of phthalates in both industrial processes and other consumer products has resulted in the ubiquitous presence of phthalates in the environment. In order to better determine the level of pollution in the environment and evaluate the potential adverse effects of exposure to DBP, immunoassay for DBP was developed. METHODOLOGY/PRINCIPAL FINDINGS: A monoclonal antibody specific to DBP was produced from a stable hybridoma cell line generated by lymphocyte hybridoma technique. An indirect competitive enzyme-linked immunosorbent assay (icELISA employing direct coating of hapten on polystyrene microtiter plates was established for the detection of DBP. Polystyrene surface was first oxidized by permanganate in dilute sulfuric acid to generate carboxyl groups. Then dibutyl 4-aminophthalate, which is an analogue of DBP, was covalently linked to the carboxyl groups of polystyrene surface with 1-ethyl-3-(3-dimethylaminopropyl carbodiimide hydrochloride (EDC. Compared with conjugate coated format (IC(50=106 ng/mL, the direct hapten coated format (IC(50=14.6 ng/mL improved assay sensitivity after careful optimization of assay conditions. The average recovery of DBP from spiked water sample was 104.4% and the average coefficient of variation was 9.95%. Good agreement of the results obtained by the hapten coated icELISA and gas chromatography-mass spectrometry further confirmed the reliability and accuracy of the icELISA for the detection of DBP in certain plastic and cosmetic samples. CONCLUSIONS/SIGNIFICANCE: The stable and efficient hybridoma cell line obtained is an unlimited source of sensitive and specific antibody to DBP. The hapten coated format is proposed as generally applicable because the carboxyl groups on modified microtiter plate surface enables stable immobilization of aminated or hydroxylated hapten with EDC. The developed

JJ1017 committee report: image examination order codes--standardized codes for imaging modality, region, and direction with local expansion: an extension of DICOM.

Science.gov (United States)

Kimura, Michio; Kuranishi, Makoto; Sukenobu, Yoshiharu; Watanabe, Hiroki; Tani, Shigeki; Sakusabe, Takaya; Nakajima, Takashi; Morimura, Shinya; Kabata, Shun

2002-06-01

The digital imaging and communications in medicine (DICOM) standard includes parts regarding nonimage data information, such as image study ordering data and performed procedure data, and is used for sharing information between HIS/RIS and modality systems, which is essential for IHE. To bring such parts of the DICOM standard into force in Japan, a joint committee of JIRA and JAHIS established the JJ1017 management guideline, specifying, for example, which items are legally required in Japan, while remaining optional in the DICOM standard. In Japan, the contents of orders from referring physicians for radiographic examinations include details of the examination. Such details are not used typically by referring physicians requesting radiographic examinations in the United States, because radiologists in the United States often determine the examination protocol. The DICOM standard has code tables for examination type, region, and direction for image examination orders. However, this investigation found that it does not include items that are detailed sufficiently for use in Japan, because of the above-mentioned reason. To overcome these drawbacks, we have generated the JJ1017 code for these 3 codes for use based on the JJ1017 guidelines. This report introduces the JJ1017 code. These codes (the study type codes in particular) must be expandable to keep up with technical advances in equipment. Expansion has 2 directions: width for covering more categories and depth for specifying the information in more detail (finer categories). The JJ1017 code takes these requirements into consideration and clearly distinguishes between the stem part as the common term and the expansion. The stem part of the JJ1017 code partially utilizes the DICOM codes to remain in line with the DICOM standard. This work is an example of how local requirements can be met by using the DICOM standard and extending it.

Evaluation of surface layer flux parameterizations using in-situ observations

Science.gov (United States)

Katz, Jeremy; Zhu, Ping

2017-09-01

Appropriate calculation of surface turbulent fluxes between the atmosphere and the underlying ocean/land surface is one of the major challenges in geosciences. In practice, the surface turbulent fluxes are estimated from the mean surface meteorological variables based on the bulk transfer model combined with the Monnin-Obukhov Similarity (MOS) theory. Few studies have been done to examine the extent to which such a flux parameterization can be applied to different weather and surface conditions. A novel validation method is developed in this study to evaluate the surface flux parameterization using in-situ observations collected at a station off the coast of Gulf of Mexico. The main findings are: (a) the theoretical prediction that uses MOS theory does not match well with those directly computed from the observations. (b) The largest spread in exchange coefficients is shown in strong stable conditions with calm winds. (c) Large turbulent eddies, which depend strongly on the mean flow pattern and surface conditions, tend to break the constant flux assumption in the surface layer.

Microbial surface displayed enzymes based biofuel cell utilizing degradation products of lignocellulosic biomass for direct electrical energy.

Science.gov (United States)

Fan, Shuqin; Hou, Chuantao; Liang, Bo; Feng, Ruirui; Liu, Aihua

2015-09-01

In this work, a bacterial surface displaying enzyme based two-compartment biofuel cell for the direct electrical energy conversion from degradation products of lignocellulosic biomass is reported. Considering that the main degradation products of the lignocellulose are glucose and xylose, xylose dehydrogenase (XDH) displayed bacteria (XDH-bacteria) and glucose dehydrogenase (GDH) displayed bacteria (GDH-bacteria) were used as anode catalysts in anode chamber with methylene blue as electron transfer mediator. While the cathode chamber was constructed with laccase/multi-walled-carbon nanotube/glassy-carbon-electrode. XDH-bacteria exhibited 1.75 times higher catalytic efficiency than GDH-bacteria. This assembled enzymatic fuel cell exhibited a high open-circuit potential of 0.80 V, acceptable stability and energy conversion efficiency. Moreover, the maximum power density of the cell could reach 53 μW cm(-2) when fueled with degradation products of corn stalk. Thus, this finding holds great potential to directly convert degradation products of biomass into electrical energy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Acoustic communication in the Greater Sage-Grouse (Centrocercus urophasianus) an examination into vocal sacs, sound propagation, and signal directionality

Science.gov (United States)

Dantzker, Marc Steven

The thesis is an inquiry into the acoustic communication of a very unusual avian species, the Greater Sage-Grouse, Centrocercus urophasianus. One of the most outstanding features of this animal's dynamic mating display is its use of paired air sacs that emerge explosively from an esophageal pouch. My first line of inquiry into this system is a review of the form and function of similar vocal apparatuses, collectively called vocal sacs, in birds. Next, with a combination of mathematical models and field measurements, My collaborator and I investigate the acoustic environment where the Greater Sage-Grouse display. The complexities of this acoustic environment are relevant both to the birds and to the subsequent examinations of the display's properties. Finally, my collaborators and I examine a cryptic component of the acoustic display --- directionality --- which we measured simultaneously from multiple locations around free moving grouse on their mating grounds.

Real-time monitoring of methanol concentration using a shear horizontal surface acoustic wave sensor for direct methanol fuel cell without reference liquid measurement

Science.gov (United States)

Tada, Kyosuke; Nozawa, Takuya; Kondoh, Jun

2017-07-01

In recent years, there has been an increasing demand for sensors that continuously measure liquid concentrations and detect abnormalities in liquid environments. In this study, a shear horizontal surface acoustic wave (SH-SAW) sensor is applied for the continuous monitoring of liquid concentrations. As the SH-SAW sensor functions using the relative measurement method, it normally needs a reference at each measurement. However, if the sensor is installed in a liquid flow cell, it is difficult to measure a reference liquid. Therefore, it is important to establish an estimation method for liquid concentrations using the SH-SAW sensor without requiring a reference measurement. In this study, the SH-SAW sensor is installed in a direct methanol fuel cell to monitor the methanol concentration. The estimated concentration is compared with a conventional density meter. Moreover, the effect of formic acid is examined. When the fuel temperature is higher than 70 °C, it is necessary to consider the influence of liquid conductivity. Here, an estimation method for these cases is also proposed.

The effect of surface anisotropy in the slippery zone of Nepenthes alata pitchers on beetle attachment

Directory of Open Access Journals (Sweden)

Elena V. Gorb

2011-06-01

Full Text Available The slippery zone in pitchers of the carnivorous plant Nepenthes alata bears scattered prominent lunate cells and displays continuous epicuticular crystalline wax coverage. The aim of this study was to examine the influence of the surface anisotropy, caused by the shape of lunate cells, on insect attachment ability. Traction tests with ladybird beetles Coccinella septempunctata were performed in two types of experiments, where surface samples of (1 intact pitchers, (2 chemically de-waxed pitchers, and (3 their polymer replicas were placed horizontally. Beetle traction forces were measured when they walked on test surfaces in either an upward (towards the peristome or downward (towards the pitcher bottom direction, corresponding to the upright or inverted positions of the pitcher. On intact pitcher surfaces covered with both lunate cells and wax crystals, experiments showed significantly higher forces in the direction towards the pitcher bottom. To distinguish between the contributions, from claw interlocking and pad adhesion, to insect attachment on the pitcher surfaces, intact versus claw-ablated beetles were used in the second type of experiment. On both de-waxed plant samples and their replicas, intact insects generated much higher forces in the downward direction compared to the upward one, whereas clawless insects did not. These results led to the conclusion that, (i due to the particular shape of lunate cells, the pitcher surface has anisotropic properties in terms of insect attachment, and (ii claws were mainly responsible for attachment enhancement in the downward pitcher direction, since, in this direction, they could interlock with overhanging edges of lunate cells.

Applications of Geomatics in Surface Mining

Science.gov (United States)

Blachowski, Jan; Górniak-Zimroz, Justyna; Milczarek, Wojciech; Pactwa, Katarzyna

2017-12-01

In terms of method of extracting mineral from deposit, mining can be classified into: surface, underground, and borehole mining. Surface mining is a form of mining, in which the soil and the rock covering the mineral deposits are removed. Types of surface mining include mainly strip and open-cast methods, as well as quarrying. Tasks associated with surface mining of minerals include: resource estimation and deposit documentation, mine planning and deposit access, mine plant development, extraction of minerals from deposits, mineral and waste processing, reclamation and reclamation of former mining grounds. At each stage of mining, geodata describing changes occurring in space during the entire life cycle of surface mining project should be taken into consideration, i.e. collected, analysed, processed, examined, distributed. These data result from direct (e.g. geodetic) and indirect (i.e. remote or relative) measurements and observations including airborne and satellite methods, geotechnical, geological and hydrogeological data, and data from other types of sensors, e.g. located on mining equipment and infrastructure, mine plans and maps. Management of such vast sources and sets of geodata, as well as information resulting from processing, integrated analysis and examining such data can be facilitated with geomatic solutions. Geomatics is a discipline of gathering, processing, interpreting, storing and delivering spatially referenced information. Thus, geomatics integrates methods and technologies used for collecting, management, processing, visualizing and distributing spatial data. In other words, its meaning covers practically every method and tool from spatial data acquisition to distribution. In this work examples of application of geomatic solutions in surface mining on representative case studies in various stages of mine operation have been presented. These applications include: prospecting and documenting mineral deposits, assessment of land accessibility

Optimizing the conditions for the microwave-assisted direct liquefaction of Ulva prolifera for bio-oil production using response surface methodology

International Nuclear Information System (INIS)

Liu, Junhai; Zhuang, Yingbin; Li, Yan; Chen, Limei; Guo, Jingxue; Li, Demao; Ye, Naihao

2013-01-01

Microwave-assisted direct liquefaction (MADL) of Ulva prolifera was performed in ethylene glycol (EG) using sulfuric acid (H 2 SO 4 ) as a catalyst. Response Surface Methodology (RSM) based on central composite rotatable design (CCRD) was employed to optimize the conditions of three independent variables (catalyst content, solvent-to-feedstock ratio and temperature) for the liquefaction yield. And the bio-oil was analyzed by elementary analysis, Fourier transform infrared spectroscopic analysis (FT-IR) and gas chromatography–mass spectrometry (GC–MS). The maximum liquefaction yield was 93.17%, which was obtained under a microwave power of 600 W for 30 min at 165 °C with a solvent-to-feedstock ratio of 18.87:1 and 4.93% sulfuric acid. The bio-oil was mainly composed of phthalic acid esters, alkenes and a fatty acid methyl ester with a long chain from C 16 to C 20 . - Highlights: • Ulva prolifera was converted to bio-oil through microwave-assisted direct liquefaction. • Response surface methodology was used to optimize the liquefaction technology. • A maximum liquefaction rate of 93.17 wt% bio-oil was obtained. • The bio-oil was composed of carboxylic acids and esters

Non destructive examination of primary wall small scale mock-up DS-1F

International Nuclear Information System (INIS)

Jeskanen, H.; Lahdenperae, K.; Kauppinen, P.; Taehtinen, S.

1998-06-01

Ultrasonic examination of primary wall small scale mock up DS-1F before thermal testing showed no major defects on studied interfaces. However, some small indications were found on copper to copper and copper to steel interfaces and surface roughness of the outer surface of copper layer gave clear indications on ultrasonic images. After thermal test a curved 50 mm long crack along the Y- direction in the middle of the heated surface of the mock up and a 220 mm long crack along the copper to copper interface on the side surface of the mock up were detected. Small cracks, less than 60-80 μm in depth, were observed on copper surface. After thermal test the corresponding ultrasonic examination showed a strong effect on ultrasonic attenuation properties and on leaky Rayleigh waves on outer surface of copper layer. A major indication was found on copper to copper interface. About 50% of the copper to copper interface was delaminated. However, some small indications found already before thermal test were also found after thermal test and they were not grown in size. No indications were observed on copper to stainless steel interfaces. Additionally, major indications were found on stainless steel tube to copper interfaces. Tubes No. 1 and 2 were almost completely whereas tube No. 3 only partly separated from copper. No indications were found on stainless steel tube to copper interface on tube No. 4. Eddy current measurements showed no volumetric or crack like flaws in the stainless steel tubes, however, delamination of the copper to copper interface along the tubes No. 1, 2 and 3 was observed. (orig.)

Metrological issues related to BRDF measurements around the specular direction in the particular case of glossy surfaces

Science.gov (United States)

Obein, Gaël.; Audenaert, Jan; Ged, Guillaume; Leloup, Frédéric B.

2015-03-01

Among the complete bidirectional reflectance distribution function (BRDF), visual gloss is principally related to physical reflection characteristics located around the specular reflection direction. This particular part of the BRDF is usually referred to as the specular peak. A good starting point for the physical description of gloss could be to measure the reflection properties around this specular peak. Unfortunately, such a characterization is not trivial, since for glossy surfaces the width of the specular peak can become very narrow (typically a full width at half maximum inferior to 0.5° is encountered). In result, new BRDF measurement devices with a very small solid angle of detection are being introduced. Yet, differences in the optical design of BRDF measurement instruments engender different measurement results for the same specimen, complicating direct comparison of the measurement results. This issue is addressed in this paper. By way of example, BRDF measurement results of two samples, one being matte and the other one glossy, obtained by use of two high level goniospectrophotometers with a different optical design, are described. Important discrepancies in the results of the glossy sample are discussed. Finally, luminance maps obtained from renderings with the acquired BRDF data are presented, exemplifying the large visual differences that might be obtained. This stresses the metrological aspects that must be known for using BRDF data. Indeed, the comprehension of parameters affecting the measurement results is an inevitable step towards progress in the metrology of surface gloss, and thus towards a better metrology of appearance in general.

Directly thiolated modification onto the surface of detonation nanodiamonds.

Science.gov (United States)

Hsu, Ming-Hua; Chuang, Hong; Cheng, Fong-Yu; Huang, Ying-Pei; Han, Chien-Chung; Chen, Jiun-Yu; Huang, Su-Chin; Chen, Jen-Kun; Wu, Dian-Syue; Chu, Hsueh-Liang; Chang, Chia-Ching

2014-05-28

An efficient method for modifying the surface of detonation nanodiamonds (5 and 100 nm) with thiol groups (-SH) by using an organic chemistry strategy is presented herein. Thiolated nanodiamonds were characterized by spectroscopic techniques, and the atomic percentage of sulfur was analyzed by elemental analysis and X-ray photoelectron spectroscopy. The conjugation between thiolated nanodiamonds and gold nanoparticles was elucidated by transmission electron microscopy and UV-vis spectrometry. Moreover, the material did not show significant cytotoxicity to the human lung carcinoma cell line and may prospectively be applied in bioconjugated technology. The new method that we elucidated may significantly improve the approach to surface modification of detonation nanodiamonds and build up a new platform for the application of nanodiamonds.

Direct ethanol production from cassava pulp using a surface-engineered yeast strain co-displaying two amylases, two cellulases, and β-glucosidase.

Science.gov (United States)

Apiwatanapiwat, Waraporn; Murata, Yoshinori; Kosugi, Akihiko; Yamada, Ryosuke; Kondo, Akihiko; Arai, Takamitsu; Rugthaworn, Prapassorn; Mori, Yutaka

2011-04-01

In order to develop a method for producing fuel ethanol from cassava pulp using cell surface engineering (arming) technology, an arming yeast co-displaying α-amylase (α-AM), glucoamylase, endoglucanase, cellobiohydrase, and β-glucosidase on the surface of the yeast cells was constructed. The novel yeast strain, possessing the activities of all enzymes, was able to produce ethanol directly from soluble starch, barley β-glucan, and acid-treated Avicel. Cassava is a major crop in Southeast Asia and used mainly for starch production. In the starch manufacturing process, large amounts of solid wastes, called cassava pulp, are produced. The major components of cassava pulp are starch (approximately 60%) and cellulose fiber (approximately 30%). We attempted simultaneous saccharification and ethanol fermentation of cassava pulp with this arming yeast. During fermentation, ethanol concentration increased as the starch and cellulose fiber substrates contained in the cassava pulp decreased. The results clearly showed that the arming yeast was able to produce ethanol directly from cassava pulp without addition of any hydrolytic enzymes.

Direct ethanol production from cassava pulp using a surface-engineered yeast strain co-displaying two amylases, two cellulases, and {beta}-glucosidase

Energy Technology Data Exchange (ETDEWEB)

Apiwatanapiwat, Waraporn; Rugthaworn, Prapassorn [Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki (Japan). Post-Harvest Science and Technology Div.; Kasetsart Univ., Bangkok (Thailand). Nanotechnology and Biotechnology Div.; Murata, Yoshinori; Kosugi, Akihiko; Arai, Takamitsu; Mori, Yutaka [Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki (Japan). Post-Harvest Science and Technology Div.; Yamada, Ryosuke; Kondo, Akihiko [Kobe Univ. (Japan). Dept. of Chemical Science and Engineering

2011-04-15

In order to develop a method for producing fuel ethanol from cassava pulp using cell surface engineering (arming) technology, an arming yeast co-displaying {alpha}-amylase ({alpha}-AM), glucoamylase, endoglucanase, cellobiohydrase, and {beta}-glucosidase on the surface of the yeast cells was constructed. The novel yeast strain, possessing the activities of all enzymes, was able to produce ethanol directly from soluble starch, barley {beta}-glucan, and acid-treated Avicel. Cassava is a major crop in Southeast Asia and used mainly for starch production. In the starch manufacturing process, large amounts of solid wastes, called cassava pulp, are produced. The major components of cassava pulp are starch (approximately 60%) and cellulose fiber (approximately 30%). We attempted simultaneous saccharification and ethanol fermentation of cassava pulp with this arming yeast. During fermentation, ethanol concentration increased as the starch and cellulose fiber substrates contained in the cassava pulp decreased. The results clearly showed that the arming yeast was able to produce ethanol directly from cassava pulp without addition of any hydrolytic enzymes. (orig.)

7 CFR 15.118 - Cross-examination.

Science.gov (United States)

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false Cross-examination. 15.118 Section 15.118 Agriculture Office of the Secretary of Agriculture NONDISCRIMINATION Rules of Practice and Procedure for Hearings...-examination. Cross-examination will be limited to the scope of direct examination and matters at issue in the...

The effects of psychotherapy treatment on outcome in bulimia nervosa: Examining indirect effects through emotion regulation, self-directed behavior, and self-discrepancy within the mediation model.

Science.gov (United States)

Peterson, Carol B; Berg, Kelly C; Crosby, Ross D; Lavender, Jason M; Accurso, Erin C; Ciao, Anna C; Smith, Tracey L; Klein, Marjorie; Mitchell, James E; Crow, Scott J; Wonderlich, Stephen A

2017-06-01

The purpose of this investigation was to examine the indirect effects of Integrative Cognitive-Affective Therapy (ICAT-BN) and Cognitive-Behavioral Therapy-Enhanced (CBT-E) on bulimia nervosa (BN) treatment outcome through three hypothesized maintenance variables: emotion regulation, self-directed behavior, and self-discrepancy. Eighty adults with BN were randomized to 21 sessions of ICAT-BN or CBT-E. A regression-based bootstrapping approach was used to test the indirect effects of treatment on outcome at end of treatment through emotion regulation and self-directed behavior measured at mid-treatment, as well as the indirect effects of treatment at follow-up through emotion regulation, self-directed behavior, and self-discrepancy measured at end of treatment. No significant differences in outcome between treatment conditions were observed, and no significant direct or indirect effects were found. Examination of the individual paths within the indirect effects models revealed comparable treatment effects. Across treatments, improvements in emotion regulation and self-directed behavior between baseline and mid-treatment predicted improvements in global eating disorder scores but not binge eating and purging frequency at end of treatment. Baseline to end of treatment improvements in emotion regulation and self-directed behavior also predicted improvements in global eating disorder scores at follow-up. Baseline to end of treatment improvements in emotion regulation predicted improvements in binge eating and baseline to end of treatment increases in positive self-directed behavior predicted improvements in purging at follow-up. These findings suggest that emotion regulation and self-directed behavior are important treatment targets and that ICAT-BN and CBT-E are comparable in modifying these psychological processes among individuals with BN. © 2017 Wiley Periodicals, Inc.

Exposure of metallic copper surface on Cu-Al2O3-carbon catalysts

NARCIS (Netherlands)

Menon, P.G.; Prasad, J.

1970-01-01

The bifunctional nature of Cu---Al2O3-on-carbon catalysts, used in the direct catalytic conversion of ethanol to ethyl acetate, prompted an examination of the dispersion of Cu on the composite catalyst. For this, the N2O-method of Osinga et al. for estimation of bare metallic copper surface on

Micro-lubrication of Directionally Oriented Contact Surfaces

Directory of Open Access Journals (Sweden)

O. Maršálek

2014-12-01

Full Text Available A description of the set of software tools for detailed computational modelling of thin lubrication layers behaviour is presented in this paper. Individual chapters outline reasons for realization of its each part, explain the functionality of each software tool and the given mathematical definition or digital implementation of all important equations or formulae. The following are examples of partial results of the analysis carried out and the resulting flow factors databases for some kinds of rough surfaces, together with an example of the analysis result of the connecting rod sliding bearing of supercharged internal combustion engine.

Microscopic examination and elemental analysis of surface defects in LEP superconducting cavities

International Nuclear Information System (INIS)

Benvenuti, C.; Cosso, R.; Hauer, M.; Hellgren, N.; Lacarrere, D.

1996-01-01

A diagnostic tool, based on a computer controlled surface analysis instrument, incorporating secondary electron imaging, static auger electron spectroscopy and scanning auger mapping has been designed and built at CERN to characterize the inner surface of LEP superconducting cavities with provide unsatisfactory radio-frequency performance. The experimental results obtained to date are reported and discussed. (author)

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.

On-surface synthesis on a bulk insulator surface

Science.gov (United States)

Richter, Antje; Floris, Andrea; Bechstein, Ralf; Kantorovich, Lev; Kühnle, Angelika

2018-04-01

On-surface synthesis has rapidly emerged as a most promising approach to prepare functional molecular structures directly on a support surface. Compared to solution synthesis, performing chemical reactions on a surface offers several exciting new options: due to the absence of a solvent, reactions can be envisioned that are otherwise not feasible due to the insolubility of the reaction product. Perhaps even more important, the confinement to a two-dimensional surface might enable reaction pathways that are not accessible otherwise. Consequently, on-surface synthesis has attracted great attention in the last decade, with an impressive number of classical reactions transferred to a surface as well as new reactions demonstrated that have no classical analogue. So far, the majority of the work has been carried out on conducting surfaces. However, when aiming for electronic decoupling of the resulting structures, e.g. for the use in future molecular electronic devices, non-conducting surfaces are highly desired. Here, we review the current status of on-surface reactions demonstrated on the (10.4) surface of the bulk insulator calcite. Besides thermally induced C-C coupling of halogen-substituted aryls, photochemically induced [2  +  2] cycloaddition has been proven possible on this surface. Moreover, experimental evidence exists for coupling of terminal alkynes as well as diacetylene polymerization. While imaging of the resulting structures with dynamic atomic force microscopy provides a direct means of reaction verification, the detailed reaction pathway often remains unclear. Especially in cases where the presence of metal atoms is known to catalyze the corresponding solution chemistry reaction (e.g. in the case of the Ullmann reaction), disclosing the precise reaction pathway is of importance to understand and generalize on-surface reactivity on a bulk insulator surface. To this end, density-functional theory calculations have proven to provide atomic

Direct Quantum Dynamics Using Grid-Based Wave Function Propagation and Machine-Learned Potential Energy Surfaces.

Science.gov (United States)

Richings, Gareth W; Habershon, Scott

2017-09-12

We describe a method for performing nuclear quantum dynamics calculations using standard, grid-based algorithms, including the multiconfiguration time-dependent Hartree (MCTDH) method, where the potential energy surface (PES) is calculated "on-the-fly". The method of Gaussian process regression (GPR) is used to construct a global representation of the PES using values of the energy at points distributed in molecular configuration space during the course of the wavepacket propagation. We demonstrate this direct dynamics approach for both an analytical PES function describing 3-dimensional proton transfer dynamics in malonaldehyde and for 2- and 6-dimensional quantum dynamics simulations of proton transfer in salicylaldimine. In the case of salicylaldimine we also perform calculations in which the PES is constructed using Hartree-Fock calculations through an interface to an ab initio electronic structure code. In all cases, the results of the quantum dynamics simulations are in excellent agreement with previous simulations of both systems yet do not require prior fitting of a PES at any stage. Our approach (implemented in a development version of the Quantics package) opens a route to performing accurate quantum dynamics simulations via wave function propagation of many-dimensional molecular systems in a direct and efficient manner.

Direct Trajectory Interpolation on the Surface using an Open CNC

OpenAIRE

Beudaert , Xavier; Lavernhe , Sylvain; Tournier , Christophe

2014-01-01

International audience; Free-form surfaces are used for many industrial applications from aeronautical parts, to molds or biomedical implants. In the common machining process, computer-aided manufacturing (CAM) software generates approximated tool paths because of the limitation induced by the input tool path format of the industrial CNC. Then, during the tool path interpolation, marks on finished surfaces can appear induced by non smooth feedrate planning. Managing the geometry of the tool p...

Silver surface enrichment of silver-copper alloys: a limitation for the analysis of ancient silver coins by surface techniques

International Nuclear Information System (INIS)

Beck, L.; Bosonnet, S.; Reveillon, S.; Eliot, D.; Pilon, F.

2004-01-01

The surface enrichment of archaeological silver-copper alloys has been recognized for many years. However, the origin of this enrichment is not well defined and many hypotheses have been put forward to account for this behaviour: segregation of the components during casting, deliberate thermal and/or chemical post-treatment, abrasion or corrosion. Among the hypotheses mentioned above, we have focused our study on the first step of coin manufacturing. Replications of silver-copper standards of various compositions ranging from 30% to 80% Ag, reflecting the composition of silver blanks, have been produced. Metallographic examination, PIXE and SEM-EDS have been used for the characterization of each sample. A model of the direct enrichment has been established. This model allows us to propose a relationship between the surface composition and the silver content of the core. Comparison with data of Roman coins from the Roman site of Cha-hat teaubleau (France) and from the literature and consequences for the analyses of ancient coins by surface methods are presented

MR imaging of brain surface structures: Surface anatomy scanning

International Nuclear Information System (INIS)

Katada, K.; Koga, S.; Asahina, M.; Kanno, T.; Asahina, K.

1987-01-01

Preoperative evaluation of brain surface anatomy, including cortical sulci and veins, relative to cerebral and cerebellar lesions is an important subject for surgeons. Until now, no imaging modality existed that allowed direct visualization of brain surface anatomy. A new MR imaging technique (surface anatomy scanning) was developed to visualize brain surface structures. The technique uses a spin-echo pulse sequence with long repetition and echo times, thick sections and a surface coil. Cortical sulci, fissures, veins, and intracranial lesions were clearly identified with this technique. Initial clinical results indicate that surface anatomy scanning is useful for lesion localization and for detailed evaluation of cortical and subcortical lesions

SURFACE TREATMENT AND EXAMINATION OF GRADE 2 AND GRADE 5 TITANIUM

Directory of Open Access Journals (Sweden)

Peter Nagy

2016-02-01

Full Text Available Surface characteristics play an important role in the implant-bone integration that is required for the long-term reliability of dental and orthopedic implants. In this paper, we investigate the effect of acid etching on the mass reduction and roughness of grade 2 and grade 5 Ti under controlled experimental conditions. Three different etching compounds were investigated: 30% HCl, 85% H3PO4 and the compound of 30% (COOH2 × 2H2O and 30% H2O2 in various treatment intervals under controlled temperature. Stereo microscopy, scanning electron microscopy, roughness and weight measurements were carried out on the samples. We found that neither 85% H3PO4 nor the compound of 30% (COOH2 × 2H2O and 30% H2O2 were able to remove the machining marks from the surface of Ti discs in our experimental setting. On the other hand, etching in 30% HCl yielded even surfaces both on Ti grade 2 and 5 discs. We also found that etching at higher temperatures in 30% HCl resulted in significant mass loss.

Silk Film Topography Directs Collective Epithelial Cell Migration

Science.gov (United States)

Rosenblatt, Mark I.

2012-01-01

The following study provides new insight into how surface topography dictates directed collective epithelial cell sheet growth through the guidance of individual cell movement. Collective cell behavior of migrating human corneal limbal-epithelial cell sheets were studied on highly biocompatible flat and micro-patterned silk film surfaces. The silk film edge topography guided the migratory direction of individual cells making up the collective epithelial sheet, which resulted in a 75% increase in total culture elongation. This was due to a 3-fold decrease in cell sheet migration rate efficiency for movement perpendicular to the topography edge. Individual cell migration direction is preferred in the parallel approach to the edge topography where localization of cytoskeletal proteins to the topography’s edge region is reduced, which results in the directed growth of the collective epithelial sheet. Findings indicate customized biomaterial surfaces may be created to direct both the migration rate and direction of tissue epithelialization. PMID:23185573

45 CFR 81.79 - Cross-examination.

Science.gov (United States)

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Cross-examination. 81.79 Section 81.79 Public... UNDER PART 80 OF THIS TITLE Hearing Procedures § 81.79 Cross-examination. A witness may be cross-examined on any matter material to the proceeding without regard to the scope of his direct examination. ...

Induced surface stress at crystal surfaces

International Nuclear Information System (INIS)

Dahmen, K.

2002-05-01

Changes of the surfaces stress Δτ (s) can be studied by observing the bending of thin crystalline plates. With this cantilever method one can gain the induced change of surface stress Δτ (s) from the bending of plates with the help of elasticity theory. For elastic isotropic substrates the relevant relations are known. Here the relations are generalized to elastic anisotropic crystals with a C 2v - Symmetry. The equilibrium shapes of crystalline plates oriented along the (100)-, (110)-, or (111)-direction which are clamped along one edge are calculated with a numeric method under the load of a homogeneous but pure isotropic or anisotropic surface stress. The results can be displayed with the dimensionality, so that the effect of clamping can be described in a systematic way. With these tabulated values one can evaluate cantilever experiments exactly. These results are generalized to cantilever methods for determining magnetoelastic constants. It is shown which magnetoelastic constants are measured in domains of thin films with ordered structures. The eigenshape and the eigenfrequency of plates constraint through a clamping at one side are calculated. These results give a deeper understanding of the elastic anisotropy. The induced surface stress of oxygen on the (110)-surface of molybdenum is measured along the principle directions Δτ [001] and Δτ [ anti 110] . The anisotropy of the surface stress is found for the p(2 x 2)-reconstruction. Lithium induces a tensile surface stress on the Molybdenum (110)-surface up to a coverage of Θ = 0, 3 monolayer. For a higher coverage the induced stress drops and reaches a level of less than -1, 2 N/m at one monolayer. It is shown, that cobalt induces a linear increasing stress with respect to the coverage on the (100)-surface of copper with a value of 2, 4GPa. The copper (100)-surface is bombarded with accelerated ions in the range between 800-2200 eV. The resulting induced compressive stress (Δτ (s) < 0) of the order

Development of ASME Code Section 11 visual examination requirements

International Nuclear Information System (INIS)

Cook, J.F.

1990-01-01

Section XI of the American Society for Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) defines three types of nondestructive examinations, visual, surface, and volumetric. Visual examination is important since it is the primary examination method for many safety-related components and systems and is also used as a backup examination for the components and systems which receive surface or volumetric examinations. Recent activity in the Section XI Code organization to improve the rules for visual examinations is reviewed and the technical basis for the new rules, which cover illumination, vision acuity, and performance demonstration, is explained

The Self- and Directed Assembly of Nanowires

Science.gov (United States)

Smith, Benjamin David

nanowires rapidly sedimented due to gravity onto a glass cover slip to concentrate and form a dense film. Particles and assemblies were imaged using inverted optical microscopy. We quantitatively analyzed the images and movies captured in order to track and classify particles and classify the overall arrays formed. We then correlated how particle characteristics, e.g., materials, size, segmentation, etc. changed the ordering and alignment observed. With that knowledge, we hope to be able to form new and interesting structures. We began our studies by examining the assembly of single component nanowires. Chapter 2 describes this work, in which solid Au nanowires measuring 2-7 mum in length and 290 nm in diameter self-assembled into smectic rows. By both experiment and theory, we determined that these rows formed due to a balance of electrostatic repulsions and van der Waals attractions. Final assemblies were stable for at least several days. Monte Carlo methods were used to simulate assemblies and showed structures that mirrored those experimentally observed. Simulations indicated that the smectic phase was preferred over others, i.e., nematic, when an additional small charge was added to the ends of the nanowires. Our particles have rough tips, which might create these additional electrostatic repulsions. To increase the particle and array complexity, two-component, metallic nanowire assembly was explored in Chapter 3. We examined numerous types of nanowires by changing the segment length, ratio, and material, the nanowire length, the surface coating, and the presence of small third segments. These segmented nanowires were generally Au-Ag and also ordered into smectic rows. Segmented wires arranged in rows, however, can be aligned in two possible ways with respect to a neighboring particle. The Au segments on neighboring particles can be oriented in the same direction or opposed to each other. Orientation was quantified in terms of an order parameter that took into account

Monitoring of tritium-contaminated surfaces, including skin

International Nuclear Information System (INIS)

Surette, R.A.; Wood, M.J.

1994-05-01

We have examined various commercially available tritium surface contamination monitors along with different swipe media and techniques for direct and indirect (swipe) monitoring of contaminated surfaces, including skin. None of the methods or instruments evaluated were more sensitive than the swipe and liquid scintillation counting (LSC) method. Swipe measurements with open-window proportional counters were, in general, less than half as sensitive as LSC, but have the advantages of having the results available almost immediately, and no sample preparation is required. The Nuclear Measurement Corporation's PC-55 is the most suitable instrument we tested for the analysis of routine swipe measurement. The PC-55 was about one third as sensitive as LSC when used with Ontario Hydro filter paper swipe media. Surface contamination measurement results can be obtained within minutes using the PC-55, compared to hours using LSC. The selection of swipe media for use with proportional counter-based instruments is critical. A medium that is electrically insulating can develop an electrostatic charge on its surface; this may alter the field gradient in the detector and may adversely influence the results. Although the PC-55 is sufficiently sensitive and very convenient, operational experience with the instrument is needed before recommending that it replace current LSC methods. The PC-55's susceptibility to internal tritium contamination may limit its practical usefulness. Because of the complexity of using live animals to evaluate direct and indirect methods for assessing skin contamination, pig skin was investigated as a possible substitute. We concluded that, for the first few hours post-exposure, pig skin mimics the kinetics of animal skin that has contacted a tritium-contaminated surface. (author). 30 refs., 1 tab., 7 figs

On the radiation exposure in temporomandibular joint examinations

International Nuclear Information System (INIS)

Rother, U.; Hildebrandt, K.H.

1979-01-01

The radiation exposure caused by standardized examinations of the temporomandibular joint has been determined with the aid of 660 exposures of an Alderson phantom. Comparative examinations were performed with the classic contact technique according to Parma to elucidate the results obtained. The lowest surface exposure was observed in contact examinations of the temporomandibular joint. Application of a flat cone led to a 13-fold reduction in surface exposure compared to contact examinations according to Parma. Furthermore, radiation exposure strongly decreased from the irradiation field to the adjacent area if a cone (flat cone and ear cone) was used. (author)

Constructive, collaborative, contextual, and self-directed learning in surface anatomy education

NARCIS (Netherlands)

Bergman-de Bres, E.M.; Sieben, J.M.; Smailbegovic, I.; Bruin, A. de; Scherpbier, A.J.J.A.; Vleuten, C.P.M. van der

2013-01-01

Anatomy education often consists of a combination of lectures and laboratory sessions, the latter frequently including surface anatomy. Studying surface anatomy enables students to elaborate on their knowledge of the cadaver's static anatomy by enabling the visualization of structures, especially

Permutation invariant potential energy surfaces for polyatomic reactions using atomistic neural networks

International Nuclear Information System (INIS)

Kolb, Brian; Zhao, Bin; Guo, Hua; Li, Jun; Jiang, Bin

2016-01-01

The applicability and accuracy of the Behler-Parrinello atomistic neural network method for fitting reactive potential energy surfaces is critically examined in three systems, H + H 2 → H 2 + H, H + H 2 O → H 2 + OH, and H + CH 4 → H 2 + CH 3 . A pragmatic Monte Carlo method is proposed to make efficient choice of the atom-centered mapping functions. The accuracy of the potential energy surfaces is not only tested by fitting errors but also validated by direct comparison in dynamically important regions and by quantum scattering calculations. Our results suggest this method is both accurate and efficient in representing multidimensional potential energy surfaces even when dissociation continua are involved.

Estimation of surface absorptivity in laser surface heating process with experimental data

International Nuclear Information System (INIS)

Chen, H-T; Wu, X-Y

2006-01-01

This study applies a hybrid technique of the Laplace transform and finite-difference methods in conjunction with the least-squares method and experimental temperature data inside the test material to predict the unknown surface temperature, heat flux and absorptivity for various surface conditions in the laser surface heating process. In this study, the functional form of the surface temperature is unknown a priori and is assumed to be a function of time before performing the inverse calculation. In addition, the whole time domain is divided into several analysis sub-time intervals and then these unknown estimates on each analysis interval can be predicted. In order to show the accuracy of the present inverse method, comparisons are made among the present estimates, direct results and previous results, showing that the present estimates agree with the direct results for the simulated problem. However, the present estimates of the surface absorptivity deviate slightly from previous estimated results under the assumption of constant thermal properties. The effect of the surface conditions on the surface absorptivity and temperature is not negligible

Direct ophthalmoscopy on YouTube

DEFF Research Database (Denmark)

Borgersen, Nanna Jo; Henriksen, Mikael Johannes Vuokko; Konge, Lars

2016-01-01

BACKGROUND: Direct ophthalmoscopy is well-suited for video-based instruction, particularly if the videos enable the student to see what the examiner sees when performing direct ophthalmoscopy. We evaluated the pedagogical effectiveness of instructional YouTube videos on direct ophthalmoscopy...... in general. We then systematically searched YouTube. Two authors reviewed eligible videos to assess eligibility and extract data on video statistics, content, and approach to visualization. Correlations between video statistics and contents were investigated using two-tailed Spearman's correlation. RESULTS...... the patient and how to examine the fundus. Time spent on fundus examination correlated with the number of views per week (Spearman's ρ=0.53; P=0.029). CONCLUSION: Videos may help overcome the pedagogical issues in teaching direct ophthalmoscopy; however, the few available videos on YouTube fail to address...

Compact surface structures for the efficient excitation of surface plasmon-polaritons

Energy Technology Data Exchange (ETDEWEB)

De la Cruz, S.; Mendez, E.R. [Division de Fisica Applicada, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Carretera Ensenada-Tijuana No. 3918, Ensenada 22860, BC (Mexico); Macias, D.; Salas-Montiel, R.; Adam, P.M. [Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de Technologie de Troyes, 12 rue Marie Curie, BP-2060, 10010 Troyes Cedex (France)

2012-06-15

We present calculations of the efficiency of excitation of surface plasmon-polaritons (SPPs) with surface structures illuminated by focussed beams. First, it is shown that the low reflectivity observed with broad highly directional beams and periodic gratings does not necessarily imply an efficient coupling to SPPs. We then consider the coupling through surface features like steps, grooves and angled steps, and calculate efficiency maps for these structures as functions of the parameters that define them. Finally, we explore the possibilities of improving the coupling efficiency using periodic structures consisting of a small number of rectangular grooves. We find that a surface section with a length of about four wavelengths can couple as much as 45% of the incident light into a directional SPP. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Directional Limits on Motion Transparency Assessed Through Colour-Motion Binding.

Science.gov (United States)

Maloney, Ryan T; Clifford, Colin W G; Mareschal, Isabelle

2018-03-01

Motion-defined transparency is the perception of two or more distinct moving surfaces at the same retinal location. We explored the limits of motion transparency using superimposed surfaces of randomly positioned dots defined by differences in motion direction and colour. In one experiment, dots were red or green and we varied the proportion of dots of a single colour that moved in a single direction ('colour-motion coherence') and measured the threshold direction difference for discriminating between two directions. When colour-motion coherences were high (e.g., 90% of red dots moving in one direction), a smaller direction difference was required to correctly bind colour with direction than at low coherences. In another experiment, we varied the direction difference between the surfaces and measured the threshold colour-motion coherence required to discriminate between them. Generally, colour-motion coherence thresholds decreased with increasing direction differences, stabilising at direction differences around 45°. Different stimulus durations were compared, and thresholds were higher at the shortest (150 ms) compared with the longest (1,000 ms) duration. These results highlight different yet interrelated aspects of the task and the fundamental limits of the mechanisms involved: the resolution of narrowly separated directions in motion processing and the local sampling of dot colours from each surface.

Direct observation of electrothermal instability structures on intensely Ohmically heated aluminum with current flowing in a surface skin layer

Science.gov (United States)

Awe, Thomas

2017-10-01

Implosions on the Z Facility assemble high-energy-density plasmas for radiation effects and ICF experiments, but achievable stagnation pressures and temperatures are degraded by the Magneto-Rayleigh-Taylor (MRT) instability. While the beryllium liners (tubes) used in Magnetized Liner Inertial Fusion (MagLIF) experiments are astonishingly smooth (10 to 50 nm RMS roughness), they also contain distributed micron-scale resistive inclusions, and large MRT amplitudes are observed. Early in the implosion, an electrothermal instability (ETI) may provide a perturbation which greatly exceeds the initial surface roughness of the liner. Resistive inhomogeneities drive nonuniform current density and Joule heating, resulting in locally higher temperature, and thus still higher resistivity. Such unstable temperature and pressure growth produce density perturbations which seed MRT. For MagLIF liners, ETI seeding of MRT has been inferred by evaluating late-time MRT, but a direct observation of ETI is not made. ETI is directly observed on the surface of 1.0-mm-diameter solid Al rods pulsed to 1 MA in 100 ns via high resolution gated optical imaging (2 ns temporal and 3 micron spatial resolution). Aluminum 6061 alloy rods, with micron-scale resistive inclusions, consistently first demonstrate overheating from distinct, 10-micron-scale, sub-eV spots, which 5-10 ns later merge into azimuthally stretched elliptical spots and discrete strata (40-100 microns wide by 10 microns tall). Axial plasma filaments form shortly thereafter. Surface plasma can be suppressed for rods coated with dielectric, enabling extended study of the evolution of stratified ETI structures, and experimental inference of ETI growth rates. This fundamentally new and highly 3-dimensional dataset informs ETI physics, including when the ETI seed of MRT may be initiated.

In situ STM imaging and direct electrochemistry of Pyrococcus furiosus ferredoxin assembled on thiolate-modified Au(111) surfaces

DEFF Research Database (Denmark)

Zhang, Jingdong; Christensen, Hans Erik Mølager; Ooi, Bee Lean

2004-01-01

We have addressed here electron transfer (ET) of Pyrococcus furiosus ferredoxin (PfFd, 7.5 kDa) in both homogeneous solution using edge plane graphite (EPG) electrodes and in the adsorbed state by electrochemistry on surface-modified single-crystal Au(111) electrodes, This has been supported...... by surface microscopic structures of PfFd monolayers, as revealed by scanning tunneling microscopy under potential control (in situ STM). Direct ET between PfFd in phosphate buffer solution, pH 7.9, and EPG electrodes is observed in the presence of promoters. Neomycin gives rise to a pair of redox peaks...... with a formal potential of ca -430 mV (vs SCE), corresponding to [3Fe-4S](1+/0). The presence of an additional promoter, which can be propionic acid, alanine, or cysteine, induces a second pair of redox peaks at similar to-900 mV (vs SCE) arising from [3Fe-4S](0/1-). A robust neomycin-PfFd complex was detected...

Evaluation of the shape of the specular peak for high glossy surfaces

Science.gov (United States)

Obein, Gaël.; Ouarets, Shiraz; Ged, Guillaume

2014-02-01

Gloss is the second most relevant visual attribute of a surface beside its colour. While the colour originates from the wavelength repartition of the reflected light, gloss originates from its angular distribution. When an observer is asked to evaluate the gloss of a surface, he always first orientate his eyes along the specular direction before lightly tilting the examined sample. This means that gloss is located in and around the specular direction, in a peak that is called the specular peak. On the one hand, this peak is flat and broad on matte surfaces on the other hand, it is narrow and sharp on high gloss surfaces. For the late ones, the FWHM of the specular peak is less than 2° which can be quite difficult to measure. We developed a dedicated facility capable of measuring specular peak with a FWHM up to 0,1 °. We measured the evolution of the peak according to the angle of illumination and the specular gloss of the sample in the restricted field of very glossy surface. The facility and peaks measured are presented in the paper. The next step will be to identify the correlations between the peak and the roughness of the sample.

TOOL ASSEMBLY WITH BI-DIRECTIONAL BEARING

Science.gov (United States)

Longhurst, G.E.

1961-07-11

A two-direction motion bearing which is incorporated in a refueling nuclear fuel element trsnsfer tool assembly is described. A plurality of bi- directional bearing assembliesare fixed equi-distantly about the circumference of the transfer tool assembly to provide the tool assembly with a bearing surface- for both axial and rotational motion. Each bi-directional bearing assembly contains a plurality of circumferentially bulged rollers mounted in a unique arrangement which will provide a bearing surface for rotational movement of the tool assembly within a bore. The bi-direc tional bearing assembly itself is capable of rational motion and thus provides for longitudinal movement of the tool assembly.

Phase transformations on the surface of YAG composite ceramics under the action of directed laser treatment

Energy Technology Data Exchange (ETDEWEB)

Vlasova, M., E-mail: vlasovamarina@inbox.ru; Márquez Aguilar, P.A.; Escobar Martinez, A.; Kakazey, M.; Guardian Tapia, R.; Trujillo Estrada, A.

2016-07-30

Highlights: • During directed laser treatment of the surface of the composite ceramics consisting of predominantly Y{sub 3}Al{sub 5}O{sub 12} and Al{sub 2}O{sub 3}, the oriented crystallization of YAG and Al{sub 2}O{sub 3} takes place. • As a result of high-temperature heating, in the surface layer of tracks, the partial dissociation of Y{sub 3}Al{sub 5}O{sub 12}, Y{sub 2}Ti{sub 2}O{sub 7}, and Al{sub 2}Y{sub 4}O{sub 9} and enrichment in YAlO{sub 3} occur. • The content of YAlO{sub 3}, the size of YAG crystallites, and their crystallographic texturing depend on the irradiation mode. • After laser treatment, the ceramic material transforms into a three-layer macrostructure consisting of the basic ceramic material, near-surface textured layer, and surface layer. - Abstract: The laser treatment of composite ceramics based on Y{sub 3}Al{sub 5}O{sub 12} with Y{sub 2}Ti{sub 2}O{sub 7}, Al{sub 2}Y{sub 4}O{sub 9}, and Al{sub 2}O{sub 3} additives is accompanied by the melting of the surface layer and formation of tracks. In the volume of tracks, the partial dissociation of Y{sub 3}Al{sub 5}O{sub 12}, Y{sub 2}Ti{sub 2}O{sub 7}, and Al{sub 2}Y{sub 4}O{sub 9}, and the formation of new phases such as YAlO{sub 3} of orthorhombic and hexagonal modifications along with the appearance of additional content of Y{sub 3}Al{sub 5}O{sub 12} and Al{sub 2}O{sub 3} are observed. The content of all these phases depends on the irradiation mode and the phase composition of the ceramics. With increase in the corundum content in ceramic specimens, in the tracks, the Al{sub 2}O{sub 3} content increases, and the Y{sub 3}Al{sub 5}O{sub 12} content decreases. In the volume of tracks, Y{sub 3}Al{sub 5}O{sub 12} crystallites are textured. The size of YAG crystallites and their crystallographic texturing depend on the irradiation mode and Y{sub 3}Al{sub 5}O{sub 12}/Al{sub 2}O{sub 3} phase ratio. On the surface of tracks, a layer enriched in YAlO{sub 3} forms. Thus, as a result of laser

Experimental study of the response functions of direct-reading instruments measuring surface-area concentration of airborne nanostructured particles

International Nuclear Information System (INIS)

Bau, Sebastien; Witschger, Olivier; Gensdarmes, Francois; Thomas, Dominique

2009-01-01

An increasing number of experimental and theoretical studies focus on airborne nanoparticles (NP) in relation with many aspects of risk assessment to move forward our understanding of the hazards, the actual exposures in the workplace, and the limits of engineering controls and personal protective equipment with regard to NP. As a consequence, generating airborne NP with controlled properties constitutes an important challenge. In parallel, toxicological studies have been carried out, and most of them support the concept that surface-area could be a relevant metric for characterizing exposure to airborne NP. To provide NP surface-area concentration measurements, some direct-reading instruments have been designed, based on attachment rate of unipolar ions to NP by diffusion. However, very few information is available concerning the performances of these instruments and the parameters that could affect their responses. In this context, our work aims at characterizing the actual available instruments providing airborne NP surface-area concentration. The instruments (a- LQ1-DC, Matter Engineering; b-AeroTrak x2122 9000, TSI; c- NSAM, TSI model 3550;) are thought to be relevant for further workplace exposure characterization and monitoring. To achieve our work, an experimental facility (named CAIMAN) was specially designed, built and characterized.

Experimental study of the response functions of direct-reading instruments measuring surface-area concentration of airborne nanostructured particles

Energy Technology Data Exchange (ETDEWEB)

Bau, Sebastien; Witschger, Olivier [Institut National de Recherche et de Securite, INRS, Laboratoire de Metrologie des Aerosols, Rue du Morvan, CS 60027, 54519 Vandoeuvre Cedex (France); Gensdarmes, Francois [Institut de Radioprotection et de Surete Nucleaire, IRSN, Laboratoire de Physique et de Metrologie des Aerosols, BP 68, 91192 Gif-sur-Yvette Cedex (France); Thomas, Dominique [Laboratoire des Sciences du Genie Chimique, LSGC/CNRS, Nancy Universite, BP 2041, 54001 Nancy Cedex (France)], E-mail: sebastien.bau@inrs.fr

2009-05-01

An increasing number of experimental and theoretical studies focus on airborne nanoparticles (NP) in relation with many aspects of risk assessment to move forward our understanding of the hazards, the actual exposures in the workplace, and the limits of engineering controls and personal protective equipment with regard to NP. As a consequence, generating airborne NP with controlled properties constitutes an important challenge. In parallel, toxicological studies have been carried out, and most of them support the concept that surface-area could be a relevant metric for characterizing exposure to airborne NP. To provide NP surface-area concentration measurements, some direct-reading instruments have been designed, based on attachment rate of unipolar ions to NP by diffusion. However, very few information is available concerning the performances of these instruments and the parameters that could affect their responses. In this context, our work aims at characterizing the actual available instruments providing airborne NP surface-area concentration. The instruments (a- LQ1-DC, Matter Engineering; b-AeroTrak{sup x2122} 9000, TSI; c- NSAM, TSI model 3550;) are thought to be relevant for further workplace exposure characterization and monitoring. To achieve our work, an experimental facility (named CAIMAN) was specially designed, built and characterized.

Wetting-layer formation mechanisms of surface-directed phase separation under different quench depths with off-critical compositions in polymer binary mixture

Science.gov (United States)

Yan, Li-Tang; Xie, Xu-Ming

2007-02-01

Focusing on the off-critical condition, the quench depth dependence of surface-directed phase separation in the polymer binary mixture is numerically investigated by combination of the Cahn-Hilliard-Cook theory and the Flory-Huggins-de Gennes theory. Two distinct situations, i.e., for the wetting, the minority component is preferred by the surface and the majority component is preferred by the surface, are discussed in detail. The simulated results show that the formation mechanism of the wetting layer is affected by both the quench depth and the off-critical extent. Moreover, a diagram, illustrating the formation mechanisms of the wetting layer with various quench depths and compositions, is obtained on the basis of the simulated results. It is found that, when the minority component is preferred by the surface, the growth of the wetting layer can exhibit pure diffusion limited growth law, logarithmic growth law, and Lifshitz-Slyozov growth law. However, when the majority component is preferred by the surface, the wetting layer always grows logarithmically, regardless of the quench depth and the off-critical extent. It is interesting that the surface-induced nucleation can be observed in this case. The simulated results demonstrate that the surface-induced nucleation only occurs below a certain value of the quench depth, and a detailed range about it is calculated and indicated. Furthermore, the formation mechanisms of the wetting layer are theoretically analyzed in depth by the chemical potential gradient.

Directed supramolecular surface assembly of SNAP-tag fusion proteins

NARCIS (Netherlands)

Uhlenheuer, D.A.; Wasserberg, D.; Haase, C.; Nguyen, H.; Schenkel, J.H.; Huskens, J.; Ravoo, B.J.; Jonkheijm, P.; Brunsveld, L.

2012-01-01

Supramolecular assembly of proteins on surfaces and vesicles was investigated by site-selective incorporation of a supramolecular guest element on proteins. Fluorescent proteins were site-selectively labeled with bisadamantane by SNAP-tag technology. The assembly of the bisadamantane functionalized

Directed Supramolecular Surface Assembly of SNAP-tag Fusion Proteins

NARCIS (Netherlands)

Uhlenheuer, D.A.; Wasserberg, D.; Haase, C.; Nguyen, Hoang D.; Schenkel, J.H.; Huskens, Jurriaan; Ravoo, B.J.; Jonkheijm, Pascal; Brunsveld, Luc

2012-01-01

Supramolecular assembly of proteins on surfaces and vesicles was investigated by site-selective incorporation of a supramolecular guest element on proteins. Fluorescent proteins were site-selectively labeled with bisadamantane by SNAP-tag technology. The assembly of the bisadamantane functionalized

The Intensity, Directionality, and Statistics of Underwater Noise From Melting Icebergs

Science.gov (United States)

Glowacki, Oskar; Deane, Grant B.; Moskalik, Mateusz

2018-05-01

Freshwater fluxes from melting icebergs and glaciers are important contributors to both sea level rise and anomalies of seawater salinity in polar regions. However, the hazards encountered close to icebergs and glaciers make it difficult to quantify their melt rates directly, motivating the development of cryoacoustics as a remote sensing technique. Recent studies have shown a qualitative link between ice melting and the accompanying underwater noise, but the properties of this signal remain poorly understood. Here we examine the intensity, directionality, and temporal statistics of the underwater noise radiated by melting icebergs in Hornsund Fjord, Svalbard, using a three-element acoustic array. We present the first estimate of noise energy per unit area associated with iceberg melt and demonstrate its qualitative dependence on exposure to surface current. Finally, we show that the analysis of noise directionality and statistics makes it possible to distinguish iceberg melt from the glacier terminus melt.

Examining changes in cellular communication in neuroendocrine cells after noble metal nanoparticle exposure.

Science.gov (United States)

Love, Sara A; Liu, Zhen; Haynes, Christy L

2012-07-07

As nanoparticles enjoy increasingly widespread use in commercial applications, the potential for unintentional exposure has become much more likely during any given day. Researchers in the field of nanotoxicity are working to determine the physicochemical nanoparticle properties that lead to toxicity in an effort to establish safe design rules. This work explores the effects of noble metal nanoparticle exposure in murine chromaffin cells, focusing on examining the effects of size and surface functionality (coating) in silver and gold, respectively. Carbon-fibre microelectrode amperometry was utilized to examine the effect of exposure on exocytosis function, at the single cell level, and provided new insights into the compromised functions of cells. Silver nanoparticles of varied size, between 15 and 60 nm diameter, were exposed to cells and found to alter the release kinetics of exocytosis for those cells exposed to the smallest examined size. Effects of gold were examined after modification with two commonly used 'bio-friendly' polymers, either heparin or poly (ethylene glycol), and gold nanoparticles were found to induce altered cellular adhesion or the number of chemical messenger molecules released, respectively. These results support the body of work suggesting that noble metal nanoparticles perturb exocytosis, typically altering the number of molecules and kinetics of release, and supports a direct disruption of the vesicle matrix by the nanoparticle. Overall, it is clear that various nanoparticle physicochemical properties, including size and surface coating, do modulate changes in cellular communication via exocytosis.

Origins of ion irradiation-induced Ga nanoparticle motion on GaAs surfaces

International Nuclear Information System (INIS)

Kang, M.; Wu, J. H.; Chen, H. Y.; Thornton, K.; Goldman, R. S.; Sofferman, D. L.; Beskin, I.

2013-01-01

We have examined the origins of ion irradiation-induced nanoparticle (NP) motion. Focused-ion-beam irradiation of GaAs surfaces induces random walks of Ga NPs, which are biased in the direction opposite to that of ion beam scanning. Although the instantaneous NP velocities are constant, the NP drift velocities are dependent on the off-normal irradiation angle, likely due to a difference in surface non-stoichiometry induced by the irradiation angle dependence of the sputtering yield. It is hypothesized that the random walks are initiated by ion irradiation-induced thermal fluctuations, with biasing driven by anisotropic mass transport

Re-examination of the threshold energy surface in copper

International Nuclear Information System (INIS)

King, W.E.; Benedek, R.; Merkle, K.L.; Meshii, M.

1981-01-01

Radiation-induced defect production in copper has been studied using in-situ electrical resistivity damage-rate measurements in the HVEM and molecular dynamics simulations. Analysis of the results yields a threshold energy surface characterized by two isolated pockets of low threshold energy centered at and surrounded by regions of much higher threshold energy; the corresponding damage function exhibits a plateau at 0.65 Frenkel pairs. A Frenkel pair resistivity of (2.75/sub -0.2/ + 0 6 ) x 10 - 4 Ω-cm is proposed. A model damage function is constructed and compared to results from ion irradiation damage-rate measurements. 7 figures

An Examination of the Quality of Wind Observations with Smartphones

Science.gov (United States)

Hintz, Kasper; Vedel, Henrik; Muñoz-Gomez, Juan; Woetmann, Niels

2017-04-01

Over the last years, the number of devices connected to the internet has increased significantly making it possible for internal and external sensors to communicate via the internet, opening up many possibilities for additional data for use in the atmospheric sciences. Vaavud has manufactured small anemometer devices which can measure wind speed and wind direction when connected to a smartphone. This work examines the quality of such crowdsourced Handheld Wind Observations (HWO). In order to examine the quality of the HWO, multiple idealised measurement sessions were performed at different sites in different atmospheric conditions. In these sessions, a high-precision ultrasonic anemometer was installed to work as a reference measurement. The HWO are extrapolated to 10 m in order to compare these to the reference observations. This allows us to examine the effect of stability correction in the surface layer and the quality of height extrapolated HWO. The height extrapolation is done using the logarithmic wind profile law with and without stability correction. Furthermore, this study examines the optimal ways of using traditional observations and numerical models to validate HWO. In order to do so, a series of numerical reanalysis have been run for a period of 5 months to quantise the effect of including crowdsourced HWO in a traditional observation dataset.

Core-shell magnetite-silica dithiocarbamate-derivatised particles achieve the Water Framework Directive quality criteria for mercury in surface waters.

Science.gov (United States)

Lopes, C B; Figueira, P; Tavares, D S; Lin, Z; Daniel-da-Silva, A L; Duarte, A C; Rocha, J; Trindade, T; Pereira, E

2013-09-01

The sorption capacity of nanoporous titanosilicate Engelhard titanosilicate number 4 (ETS-4) and silica-coated magnetite particles derivatised with dithiocarbamate groups towards Hg(II) was evaluated and compared in spiked ultra-pure and spiked surface-river water, for different batch factors. In the former, and using a batch factor of 100 m(3)/kg and an initial Hg(II) concentrations matching the maximum allowed concentration in an effluent discharge, both materials achieve Hg(II) uptake efficiencies in excess of 99 % and a residual metal concentration lower than the guideline value for drinking water quality. For the surface-river water and the same initial concentration, the Hg(II) uptake efficiency of magnetite particles is outstanding, achieving the quality criteria established by the Water Framework Directive (concerning Hg concentration in surface waters) using a batch factor of 50 m(3)/kg, while the efficiency of ETS-4 is significantly inferior. The dissimilar sorbents' Hg(II) removal efficiency is attributed to different uptake mechanisms. This study also highlights the importance of assessing the effective capacity of the sorbents under realistic conditions in order to achieve trustable results.

n-Alkane adsorption to polar silica surfaces.

Science.gov (United States)

Brindza, Michael R; Ding, Feng; Fourkas, John T; Walker, Robert A

2010-03-21

The structures of medium-length n-alkane species (C(8)-C(11)) adsorbed to a hydrophilic silica/vapor interface were examined using vibrational sum frequency spectroscopy. Experiments sampling out-of-plane orientation show a clear pattern in vibrational band intensities that implies chains having primarily all-trans conformations lying flat along the interface. Further analysis shows that the methylene groups of the alkane chains have their local symmetry axes directed into and away from the surface. Spectra acquired under different polarization conditions interlock to reinforce this picture of interfacial structure and organization. Variation in signal intensities with chain length suggests that correlation between adsorbed monomers weakens with increasing chain length. This result stands in contrast with alkane behavior at neat liquid/vapor interfaces where longer length alkanes show considerably more surface induced ordering than short chain alkanes.

Simultaneous Retrieval of Aerosol and Surface Optical Properties from Combined Airborne- and Ground-Based Direct and Diffuse Radiometric Measurements

Science.gov (United States)

Gatebe, C. K.; Dubovik, O.; King, M. D.; Sinyuk, A.

2010-01-01

This paper presents a new method for simultaneously retrieving aerosol and surface reflectance properties from combined airborne and ground-based direct and diffuse radiometric measurements. The method is based on the standard Aerosol Robotic Network (AERONET) method for retrieving aerosol size distribution, complex index of refraction, and single scattering albedo, but modified to retrieve aerosol properties in two layers, below and above the aircraft, and parameters on surface optical properties from combined datasets (Cloud Absorption Radiometer (CAR) and AERONET data). A key advantage of this method is the inversion of all available spectral and angular data at the same time, while accounting for the influence of noise in the inversion procedure using statistical optimization. The wide spectral (0.34-2.30 m) and angular range (180 ) of the CAR instrument, combined with observations from an AERONET sunphotometer, provide sufficient measurement constraints for characterizing aerosol and surface properties with minimal assumptions. The robustness of the method was tested on observations made during four different field campaigns: (a) the Southern African Regional Science Initiative 2000 over Mongu, Zambia, (b) the Intercontinental Transport Experiment-Phase B over Mexico City, Mexico (c) Cloud and Land Surface Interaction Campaign over the Atmospheric Radiation Measurement (ARM) Central Facility, Oklahoma, USA, and (d) the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) over Elson Lagoon in Barrow, Alaska, USA. The four areas are dominated by different surface characteristics and aerosol types, and therefore provide good test cases for the new inversion method.

Sliding spool design for reducing the actuation forces in direct operated proportional directional valves: Experimental validation

International Nuclear Information System (INIS)

Amirante, Riccardo; Distaso, Elia; Tamburrano, Paolo

2016-01-01

Highlights: • An innovative procedure to design a commercial proportional directional valve is shown. • Experimental tests are performed to demonstrate the flow force reduction. • The design is improved by means of a previously made optimization procedure. • Great reduction in the flow forces without reducing the flow rate is demonstrated. - Abstract: This paper presents the experimental validation of a new methodology for the design of the spool surfaces of four way three position direct operated proportional directional valves. The proposed methodology is based on the re-design of both the compensation profile (the central conical surface of the spool) and the lateral surfaces of the spool, in order to reduce the flow forces acting on the spool and hence the actuation forces. The aim of this work is to extend the application range of these valves to higher values of pressure and flow rate, thus avoiding the employment of more expensive two stage configurations in the case of high-pressure conditions and/or flow rate. The paper first presents a theoretical approach and a general strategy for the sliding spool design to be applied to any four way three position direct operated proportional directional valve. Then, the proposed approach is experimentally validated on a commercially available valve using a hydraulic circuit capable of measuring the flow rate as well as the actuation force over the entire spool stroke. The experimental results, performed using both the electronic driver provided by the manufacturer and a manual actuation system, show that the novel spool surface requires remarkably lower actuation forces compared to the commercial configuration, while maintaining the same flow rate trend as a function of the spool position.

38 CFR 18b.58 - Cross-examination.

Science.gov (United States)

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Cross-examination. 18b.58... Procedures § 18b.58 Cross-examination. A witness may be cross-examined on any matter material to the proceeding without regard to the scope of his direct examination. ...

Regional-Scale Surface Magnetic Fields and Proton Fluxes to Mercury's Surface from Proton-Reflection Magnetometry

Science.gov (United States)

Winslow, R. M.; Johnson, C. L.; Anderson, B. J.; Gershman, D. J.; Raines, J. M.; Lillis, R. J.; Korth, H.; Slavin, J. A.; Solomon, S. C.; Zurbuchen, T.

2014-12-01

The application of a recently developed proton-reflection magnetometry technique to MESSENGER spacecraft observations at Mercury has yielded two significant findings. First, loss-cone observations directly confirm particle precipitation to Mercury's surface and indicate that solar wind plasma persistently bombards the planet not only in the magnetic cusp regions but over a large fraction of the southern hemisphere. Second, the inferred surface field strengths independently confirm the north-south asymmetry in Mercury's global magnetic field structure first documented from observations of magnetic equator crossings. Here we extend this work with 1.5 additional years of observations (i.e., to 2.5 years in all) to further probe Mercury's surface magnetic field and better resolve proton flux precipitation to the planet's surface. We map regions where proton loss cones are observed; these maps indicate regions where protons precipitate directly onto the surface. The augmentation of our data set over that used in our original study allows us to examine the proton loss cones in cells of dimension 10° latitude by 20° longitude in Mercury body-fixed coordinates. We observe a transition from double-sided to single-sided loss cones in the pitch-angle distributions; this transition marks the boundary between open and closed field lines. At the surface this boundary lies between 60° and 70°N. Our observations allow the estimation of surface magnetic field strengths in the northern cusp region and the calculation of incident proton fluxes to both hemispheres. In the northern cusp, our regional-scale observations are consistent with an offset dipole field and a dipole moment of 190 nT RM3, where RM is Mercury's radius, implying that any regional-scale variations in surface magnetic field strengths are either weak relative to the dipole field or occur at length scales smaller than the resolution of our observations (~300 km). From the global proton flux map (north of 40° S

The Influence of Electrolytic Concentration on the Electrochemical Deposition of Calcium Phosphate Coating on a Direct Laser Metal Forming Surface

Directory of Open Access Journals (Sweden)

Qianyue Sun

2017-01-01

Full Text Available A calcium phosphate (CaP coating on titanium surface enhances its biocompatibility, thus facilitating osteoconduction and osteoinduction with the inorganic phase of the human bone. Electrochemical deposition has been suggested as an effective means of fabricating CaP coatings on porous surface. The purpose of this study was to develop CaP coatings on a direct laser metal forming implant using electrochemical deposition and to investigate the effect of electrolytic concentration on the coating’s morphology and structure by X-ray diffraction, scanning electron microscopy, water contact angle analysis, and Fourier transform infrared spectroscopy. In group 10−2, coatings were rich in dicalcium phosphate, characterized to be thick, layered, and disordered plates. In contrast, in groups 10−3 and 10−4, the relatively thin and well-ordered coatings predominantly consisted of granular hydroxyapatite. Further, the hydrophilicity and cell affinity were improved as electrolytic concentration increased. In particular, the cells cultured in group 10−3 appeared to have spindle morphology with thick pseudopodia on CaP coatings; these spindles and pseudopodia strongly adhered to the rough and porous surface. By analyzing and evaluating the surface properties, we provided further knowledge on the electrolytic concentration effect, which will be critical for improving CaP coated Ti implants in the future.

Target surface condition during reactive glow discharge sputtering of copper

International Nuclear Information System (INIS)

Depla, D; Haemers, J; Gryse, R De

2002-01-01

During reactive glow discharge sputtering of copper in an argon/nitrogen plasma, we noticed an abrupt change of the target voltage and the deposition rate when the nitrogen concentration in the plasma exceeds a critical value. To explain this behaviour, the target surface after reactive glow discharge sputtering was examined by x-ray photoelectron spectroscopy (XPS). An experimental arrangement was constructed that allows direct transfer of the glow discharge cathode to the XPS analysis chamber without air exposure. These XPS measurements revealed that several different chemical states of nitrogen are present in the layer that forms on the target surface. The relative concentration of these different states changes when the critical nitrogen concentration in the plasma is exceeded

Monitoring of tritium-contaminated surfaces, including skin

Energy Technology Data Exchange (ETDEWEB)

Surette, R A; Wood, M J

1994-05-01

We have examined various commercially available tritium surface contamination monitors along with different swipe media and techniques for direct and indirect (swipe) monitoring of contaminated surfaces, including skin. None of the methods or instruments evaluated were more sensitive than the swipe and liquid scintillation counting (LSC) method. Swipe measurements with open-window proportional counters were, in general, less than half as sensitive as LSC, but have the advantages of having the results available almost immediately, and no sample preparation is required. The Nuclear Measurement Corporation`s PC-55 is the most suitable instrument we tested for the analysis of routine swipe measurement. The PC-55 was about one third as sensitive as LSC when used with Ontario Hydro filter paper swipe media. Surface contamination measurement results can be obtained within minutes using the PC-55, compared to hours using LSC. The selection of swipe media for use with proportional counter-based instruments is critical. A medium that is electrically insulating can develop an electrostatic charge on its surface; this may alter the field gradient in the detector and may adversely influence the results. Although the PC-55 is sufficiently sensitive and very convenient, operational experience with the instrument is needed before recommending that it replace current LSC methods. The PC-55`s susceptibility to internal tritium contamination may limit its practical usefulness. Because of the complexity of using live animals to evaluate direct and indirect methods for assessing skin contamination, pig skin was investigated as a possible substitute. We concluded that, for the first few hours post-exposure, pig skin mimics the kinetics of animal skin that has contacted a tritium-contaminated surface. (author). 30 refs., 1 tab., 7 figs.

The importance of surface finish to energy performance

Directory of Open Access Journals (Sweden)

Smith Geoff B.

2017-01-01

Full Text Available Power generation in solar energy systems, thermal control in buildings and mitigation of the Urban Heat Island problem, are all sensitive to directional response to incoming radiation. The radiation absorption and emission profile also plays a crucial role in each system's response and depends strongly on surface finish. This important sensitivity needs wider recognition in materials data sheets, system modeling, plus in materials and environmental engineering. The impact of surface roughness on thermal response of natural and man-made external environments is examined. Important examples will be given of the role of surface finish within each class. Total emittance links to the way surface finish influences directional emittance E(θ. Smooth surface thermal emittance on PV module covers, many solar absorbers, some roof paints, polished concrete, and glass windows can be up to 15% different from insulator results based on fully diffuse models of the same material. Widespread evidence indicates smooth metals and low-E solar absorber surfaces cool faster, and smooth insulators slower than previously thought. Matt paint is cooler than low sheen paint under the same solar heating impacts and normal concrete cooler than polished. Emittance for water is the prime environmental example of oblique impacts as it reflects strongly at oblique incidence, which leads to a significant drop in E(θ. Ripples or waves however raise water's average emittance. A surprise in this work was the high sensitivity of total E and its angular components to roughness in the depth range of 0.1–0.8 μm, which are well under ambient thermal IR wavelengths of 3–30 μm but common in metal finishing. Parallel energy flows such as evaporation and convective cooling vary if emittance varies. Thermal image analysis can provide insights into angular radiative effects.

Comparison of the clinical examination with the panoramic radiography in the diagnosis of dental caries

Energy Technology Data Exchange (ETDEWEB)

Choi, Hang Moon [Dept. of Oral and Maxillofacial Radiology and Dental Research Institute, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

1999-02-15

The objective of this study was to compare clinical examination of of dental caries and secondary caries with panoramic examination, and to examine bone lesions and dental anomaly of unerupted state. In this study, clinical records and panoramic radiographs were available for 89 first grade students in elementary school. Dental caries of occlusal surfaces, proximal surfaces, and buccolingual surfaces were examined. Secondary caries was examined too. In addition, the central lesion and dental anomaly of unerupted state were examined in panoramic radiographs. The obtained results were as followed :1. Carious detectability of clinical examination in occlusal and buccolingual surface was higher than that of panoramic examination, but it is statistically insignificant (p>0.05). In proximal surface, carious detectability of panoramic examination was higher than that of clinical examination, and it is statistically significant (p<0.01). 2. In contrast to clinical examination only, when the two examination methods were combined, there was additional detection of dental caries (26.7% in occlusal surface, 48.2% in proximal surface, 33.3% in buccolingual surface, and 38.3% totally). 3. In detection of secondary caries, panoramic examination had lower ability than clinical examination in all three surfaces, but in case that both methods were combined, totally 36.0% extra carious lesions were detected. 4. In panoramic examination, detectability of secondary caries in upper teeth is lower than lower teeth. 5. In panoramic examination, it was possible to detect the central lesions and dental anomalies of unerupted state which cannot be detected in clinical examination. It is useful to combine the panoramic examination with clinical examination in order to increase carious detectability and to evaluate the central lesions and dental anomalies of unerupted state.

Comparison of the clinical examination with the panoramic radiography in the diagnosis of dental caries

International Nuclear Information System (INIS)

Choi, Hang Moon

1999-01-01

The objective of this study was to compare clinical examination of of dental caries and secondary caries with panoramic examination, and to examine bone lesions and dental anomaly of unerupted state. In this study, clinical records and panoramic radiographs were available for 89 first grade students in elementary school. Dental caries of occlusal surfaces, proximal surfaces, and buccolingual surfaces were examined. Secondary caries was examined too. In addition, the central lesion and dental anomaly of unerupted state were examined in panoramic radiographs. The obtained results were as followed :1. Carious detectability of clinical examination in occlusal and buccolingual surface was higher than that of panoramic examination, but it is statistically insignificant (p>0.05). In proximal surface, carious detectability of panoramic examination was higher than that of clinical examination, and it is statistically significant (p<0.01). 2. In contrast to clinical examination only, when the two examination methods were combined, there was additional detection of dental caries (26.7% in occlusal surface, 48.2% in proximal surface, 33.3% in buccolingual surface, and 38.3% totally). 3. In detection of secondary caries, panoramic examination had lower ability than clinical examination in all three surfaces, but in case that both methods were combined, totally 36.0% extra carious lesions were detected. 4. In panoramic examination, detectability of secondary caries in upper teeth is lower than lower teeth. 5. In panoramic examination, it was possible to detect the central lesions and dental anomalies of unerupted state which cannot be detected in clinical examination. It is useful to combine the panoramic examination with clinical examination in order to increase carious detectability and to evaluate the central lesions and dental anomalies of unerupted state.

The influence of the surface atomic structure on surface diffusion

International Nuclear Information System (INIS)

Ghaleb, Dominique

1984-03-01

This work represents the first quantitative study of the influence of the surface atomic structure on surface diffusion (in the range: 0.2 Tf up 0.5 Tf; Tf: melting temperature of the substrate). The analysis of our results on a microscopic scale shows low formation and migration energies for adatoms; we can describe the diffusion on surfaces with a very simple model. On (110) surfaces at low temperature the diffusion is controlled by the exchange mechanism; at higher temperature direct jumps of adatoms along the channels contribute also to the diffusion process. (author) [fr

Directed Growth of Virus Nanofilaments on a Superhydrophobic Surface

KAUST Repository

Marinaro, Giovanni

2015-06-17

The evaporation of single droplets of colloidal tobacco mosaic virus (TMV) nanoparticles on a superhydrophobic surface with a hexagonal pillar-pattern results in the formation of coffee-ring type residues. We imaged surface features by optical, scanning electron, and atomic force microscopies. Bulk features were probed by raster-scan X-ray nanodiffraction. At ∼100 pg/μL nanoparticle concentration, the rim of the residue connects to neighboring pillars via fibrous extensions containing flow-aligned crystalline domains. At ∼1 pg/μL nanoparticle concentration, nanofilaments of ¥80 nm diameter and ∼20 μm length are formed, extending normal to the residue-rim across a range of pillars. X-ray scattering is dominated by the nanofilament form-factor but some evidence for crystallinity has been obtained. The observation of sheets composed of stacks of self-assembled nanoparticles deposited on pillars suggests that the nanofilaments are drawn from a structured droplet interface. © 2015 American Chemical Society.

Directed Growth of Virus Nanofilaments on a Superhydrophobic Surface

KAUST Repository

Marinaro, Giovanni; Burghammer, Manfred; Costa, Luca; Dane, Thomas; De Angelis, Francesco; Di Fabrizio, Enzo M.; Riekel, Christian

2015-01-01

The evaporation of single droplets of colloidal tobacco mosaic virus (TMV) nanoparticles on a superhydrophobic surface with a hexagonal pillar-pattern results in the formation of coffee-ring type residues. We imaged surface features by optical, scanning electron, and atomic force microscopies. Bulk features were probed by raster-scan X-ray nanodiffraction. At ∼100 pg/μL nanoparticle concentration, the rim of the residue connects to neighboring pillars via fibrous extensions containing flow-aligned crystalline domains. At ∼1 pg/μL nanoparticle concentration, nanofilaments of ¥80 nm diameter and ∼20 μm length are formed, extending normal to the residue-rim across a range of pillars. X-ray scattering is dominated by the nanofilament form-factor but some evidence for crystallinity has been obtained. The observation of sheets composed of stacks of self-assembled nanoparticles deposited on pillars suggests that the nanofilaments are drawn from a structured droplet interface. © 2015 American Chemical Society.

Permutation invariant potential energy surfaces for polyatomic reactions using atomistic neural networks

Energy Technology Data Exchange (ETDEWEB)

Kolb, Brian [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Zhao, Bin; Guo, Hua, E-mail: hguo@unm.edu [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Li, Jun [School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331 (China); Jiang, Bin [Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2016-06-14

The applicability and accuracy of the Behler-Parrinello atomistic neural network method for fitting reactive potential energy surfaces is critically examined in three systems, H + H{sub 2} → H{sub 2} + H, H + H{sub 2}O → H{sub 2} + OH, and H + CH{sub 4} → H{sub 2} + CH{sub 3}. A pragmatic Monte Carlo method is proposed to make efficient choice of the atom-centered mapping functions. The accuracy of the potential energy surfaces is not only tested by fitting errors but also validated by direct comparison in dynamically important regions and by quantum scattering calculations. Our results suggest this method is both accurate and efficient in representing multidimensional potential energy surfaces even when dissociation continua are involved.

Mixing of two co-directional Rayleigh surface waves in a nonlinear elastic material.

Science.gov (United States)

Morlock, Merlin B; Kim, Jin-Yeon; Jacobs, Laurence J; Qu, Jianmin

2015-01-01

The mixing of two co-directional, initially monochromatic Rayleigh surface waves in an isotropic, homogeneous, and nonlinear elastic solid is investigated using analytical, finite element method, and experimental approaches. The analytical investigations show that while the horizontal velocity component can form a shock wave, the vertical velocity component can form a pulse independent of the specific ratios of the fundamental frequencies and amplitudes that are mixed. This analytical model is then used to simulate the development of the fundamentals, second harmonics, and the sum and difference frequency components over the propagation distance. The analytical model is further extended to include diffraction effects in the parabolic approximation. Finally, the frequency and amplitude ratios of the fundamentals are identified which provide maximum amplitudes of the second harmonics as well as of the sum and difference frequency components, to help guide effective material characterization; this approach should make it possible to measure the acoustic nonlinearity of a solid not only with the second harmonics, but also with the sum and difference frequency components. Results of the analytical investigations are then confirmed using the finite element method and the experimental feasibility of the proposed technique is validated for an aluminum specimen.

Sensing roughness and polish direction

DEFF Research Database (Denmark)

Jakobsen, Michael Linde; Olesen, Anders Sig; Larsen, Henning Engelbrecht

2016-01-01

As a part of the work carried out in a project supported by the Danish Council for Technology and Innovation, we have investigated the option of smoothing standard CNC-machined surfaces. In the process of constructing optical prototypes, involving custom-designed optics, the development cost...... and time consumption can become prohibitive in a research budget. Machining the optical surfaces directly is expensive and time consuming. Alternatively, a more standardized and cheaper machining method can be used, calling for the object to be manually polished. During the polishing process, the operator...... needs information about the RMS-value of the surface roughness and the current direction of the scratches introduced by the polishing process. The RMS-value indicates to the operator how far he is from the final finish, and the scratch orientation is often specified by the customer in order to avoid...

Direct Observation of Molecular Preorganization for Chirality Transfer on a Catalyst Surface

DEFF Research Database (Denmark)

Demers-Carpentier, Vincent; Goubert,, Guillaume; Masini, Federico

2011-01-01

The chemisorption of specific optically active compounds on metal surfaces can create catalytically active chirality transfer sites. However, the mechanism through which these sites bias the stereoselectivity of reactions (typically hydrogenations) is generally assumed to be so complex that conti......The chemisorption of specific optically active compounds on metal surfaces can create catalytically active chirality transfer sites. However, the mechanism through which these sites bias the stereoselectivity of reactions (typically hydrogenations) is generally assumed to be so complex...... functional theory calculations reveals the stereodirecting forces governing preorganization into precise chiral modifier-substrate bimolecular surface complexes. The study shows that the chiral modifier induces prochiral switching on the surface and that different prochiral ratios prevail at different...

Direct Experimental Evidence of Back-Surface Acceleration from Laser-Irradiated Foils

International Nuclear Information System (INIS)

Allen, M; Patel, P; Mackinnon, A; Price, D; Wilks, S; Morse, E

2004-01-01

Au foils were irradiated with a 100-TW, 100-fs laser at intensities greater than 10 20 W/cm 2 producing proton beams with a total yield of ∼ 10 11 and maximum proton energy of > 9 MeV. Removing contamination from the back surface of Au foils with an Ar-ion sputter gun reduced the total yield of accelerated protons to less than 1% of the yield observed without removing contamination. Removing contamination the front surface (laser-interaction side) of the target had no observable effect on the proton beam. We present a one-dimensional particle-in-cell simulation that models the experiment. Both experimental and simulation results are consistent with the back-surface acceleration mechanism described in the text

Surface modification of indium tin oxide for direct writing of silver nanoparticulate ink micropatterns

International Nuclear Information System (INIS)

Vunnam, Swathi; Ankireddy, Krishnamraju; Kellar, Jon; Cross, William

2013-01-01

Surface treatment techniques were deployed to alter the surface of indium tin oxide (ITO) samples to attain a favorable interface between printed nano-inks and ITO surface. Surface free energy components of treated ITO substrates were calculated for each treatment using the van Oss–Chaudhury–Good method. The surface treatments of ITO changed the Lifshitz–van der Waals and Lewis acid–base components, and contact angle hysteresis significantly. Among all the surface treatments, air plasma treated samples showed high polar in nature, whereas dodecyltrichlorosilane self-assembled monolayer treated sample showed the lowest. In addition to the polarity and homogeneity, the surface roughness of the ITO was studied with respect to the surface treatment. Silver nanoparticulate ink was printed on treated ITO surfaces using aerosol jet printing system. Printed silver nano-ink line width and morphology strongly depended on the surface treatment of the ITO, ink properties and printing parameters. - Highlights: ► Surface treatments on indium tin oxide (ITO) altered its surface free energy. ► Surface free energies were studied in terms of acid–base components. ► ITO surface morphology and roughness were changed with the surface treatment. ► Silver ink was printed on treated ITO samples using aerosol jet printing system. ► Line widths of printed patterns clearly depended on the surface free energy of ITO

Surface modification of indium tin oxide for direct writing of silver nanoparticulate ink micropatterns

Energy Technology Data Exchange (ETDEWEB)

Vunnam, Swathi, E-mail: swathi.vunnam@mines.sdsmt.edu [Nanoscience and Nanoengineering Department, South Dakota School of Mines and Technology, Rapid City, SD-57701 (United States); Ankireddy, Krishnamraju; Kellar, Jon; Cross, William [Department of Materials and Metallurgical Engineering, South Dakota School of Mines and Technology, Rapid City, SD-57701 (United States)

2013-03-01

Surface treatment techniques were deployed to alter the surface of indium tin oxide (ITO) samples to attain a favorable interface between printed nano-inks and ITO surface. Surface free energy components of treated ITO substrates were calculated for each treatment using the van Oss–Chaudhury–Good method. The surface treatments of ITO changed the Lifshitz–van der Waals and Lewis acid–base components, and contact angle hysteresis significantly. Among all the surface treatments, air plasma treated samples showed high polar in nature, whereas dodecyltrichlorosilane self-assembled monolayer treated sample showed the lowest. In addition to the polarity and homogeneity, the surface roughness of the ITO was studied with respect to the surface treatment. Silver nanoparticulate ink was printed on treated ITO surfaces using aerosol jet printing system. Printed silver nano-ink line width and morphology strongly depended on the surface treatment of the ITO, ink properties and printing parameters. - Highlights: ► Surface treatments on indium tin oxide (ITO) altered its surface free energy. ► Surface free energies were studied in terms of acid–base components. ► ITO surface morphology and roughness were changed with the surface treatment. ► Silver ink was printed on treated ITO samples using aerosol jet printing system. ► Line widths of printed patterns clearly depended on the surface free energy of ITO.

NOx Binding and Dissociation: Enhanced Ferroelectric Surface Chemistry by Catalytic Monolayers

Science.gov (United States)

Kakekhani, Arvin; Ismail-Beigi, Sohrab

2013-03-01

NOx molecules are regulated air pollutants produced during automotive combustion. As part of an effort to design viable catalysts for NOx decomposition operating at higher temperatures that would allow for improved fuel efficiency, we examine NOx chemistry on ferroelectric perovskite surfaces. Changing the direction of ferroelectric polarization can modify surface electronic properties and may lead to switchable surface chemistry. Here, we describe our recent work on potentially enhanced surface chemistry using catalytic RuO2 monolayers on perovskite ferroelectric substrates. In addition to thermodynamic stabilization of the RuO2 layer, we present results on the polarization-dependent binding of NO, O2, N2, and atomic O and N. We present results showing that one key problem with current catalysts, involving the difficulty of releasing dissociation products (especially oxygen), can be ameliorated by this method. Primary support from Toyota Motor Engineering and Manufacturing, North America, Inc.

Cuttlefish see shape from shading, fine-tuning coloration in response to pictorial depth cues and directional illumination.

Science.gov (United States)

Zylinski, Sarah; Osorio, D; Johnsen, Sonke

2016-03-16

Humans use shading as a cue to three-dimensional form by combining low-level information about light intensity with high-level knowledge about objects and the environment. Here, we examine how cuttlefish Sepia officinalis respond to light and shadow to shade the white square (WS) feature in their body pattern. Cuttlefish display the WS in the presence of pebble-like objects, and they can shade it to render the appearance of surface curvature to a human observer, which might benefit camouflage. Here we test how they colour the WS on visual backgrounds containing two-dimensional circular stimuli, some of which were shaded to suggest surface curvature, whereas others were uniformly coloured or divided into dark and light semicircles. WS shading, measured by lateral asymmetry, was greatest when the animal rested on a background of shaded circles and three-dimensional hemispheres, and less on plain white circles or black/white semicircles. In addition, shading was enhanced when light fell from the lighter side of the shaded stimulus, as expected for real convex surfaces. Thus, the cuttlefish acts as if it perceives surface curvature from shading, and takes account of the direction of illumination. However, the direction of WS shading is insensitive to the directions of background shading and illumination; instead the cuttlefish tend to turn to face the light source. © 2016 The Author(s).

Evaluating the Use of Tree Shelters for Direct Seeding of Castanea on a Surface Mine in Appalachia

Directory of Open Access Journals (Sweden)

Christopher Barton

2015-10-01

Full Text Available American chestnut (Castanea dentata, once a primary constituent of the eastern hardwood forest ecosystem, was nearly extirpated from the forest canopy by the accidental introduction of chestnut blight (Cryphonectria parasitica. An intensive breeding program has sought to breed blight resistance from Chinese chestnut into American chestnuts, while maintaining as much of the desirable American chestnut phenotypes as possible. Previous studies suggest that these blight resistant American chestnuts, termed “restoration chestnuts”, are capable of thriving on reclaimed surface mines. We direct seeded pure Chinese, pure American, and three backcross lines into brown sandstone minesoil on a mine site in Pike County, KY. To investigate the effects of tree sheltering on survival and growth, we installed tree shelters on half the plots, and left the rest of the plots unsheltered. Results indicated that shelters were highly effective at reducing initial mortality. In addition, while pure Chinese chestnut survival was highest, the three backcross lines have also survived well on this site. Our study demonstrates that American, Chinese, and backcrossed chestnuts can survive through five growing seasons on reclaimed surface mines with the use of tree shelters.

Influence of flow direction and flow rate on the initial adhesion of seven Listeria monocytogenes strains to fine polished stainless steel

DEFF Research Database (Denmark)

Skovager, Anne; Whitehead, Kathryn; Siegumfeldt, Henrik

2012-01-01

The effects of flow direction and shear stress on the adhesion of different strains of Listeria monocytogenes to fine polished stainless steel under liquid flow conditions were investigated. Furthermore, the relationship between cell surface properties and cell size and the initial adhesion rate...... (IAR) was studied. A method, including fluorescence microscopy and a flow perfusion system, was developed and used to examine the real-time initial cell adhesion of different L. monocytogenes species in situ to opaque surfaces under flow conditions. The results demonstrated that shear stress...... was the determining factor for the initial adhesion of L. monocytogenes under flow conditions. The flow direction in relation to the orientation of surface features (the scratches) could be disregarded. IARs were dependent on the shear stress and strain type. The strain EGDe, which had the lowest IAR, had the largest...

Phospholipids as an alternative to direct covalent coupling: surface functionalization of nanoporous alumina for protein recognition and purification.

Science.gov (United States)

Lazzara, Thomas D; Behn, Daniela; Kliesch, Torben-Tobias; Janshoff, Andreas; Steinem, Claudia

2012-01-15

Anodic aluminum oxide (AAO) substrates with aligned, cylindrical, non-intersecting pores with diameters of 75 nm and depths of 3.5 or 10 μm were functionalized with lipid monolayers harboring different receptor lipids. AAO was first functionalized with dodecyl-trichlorosilane, followed by fusion of small unilamellar vesicles (SUVs) forming a lipid monolayer. The SUVs' lipid composition was transferred onto the AAO surface, allowing us to control the surface receptor density. Owing to the optical transparency of the AAO, the overall vesicle spreading process and subsequent protein binding to the receptor-doped lipid monolayers could be investigated in situ by optical waveguide spectroscopy (OWS). SUV spreading occurred at the pore-rim interface, followed by lateral diffusion of lipids within the pore-interior surface until homogeneous coverage was achieved with a lipid monolayer. The functionality of the system was demonstrated through streptavidin binding onto a biotin-DOPE containing POPC membrane, showing maximum protein coverage at 10 mol% of biotin-DOPE. The system enabled us to monitor in real-time the selective extraction of two histidine-tagged proteins, PIGEA14 (14 kDa) and ezrin (70 kDa), directly from cell lysate solutions using a DOGS-NTA(Ni)/DOPC (1:9) membrane. The purification process including protein binding and elution was monitored by OWS and confirmed by SDS-PAGE. Copyright © 2011 Elsevier Inc. All rights reserved.

Versatile Surface Functionalization of Metal-Organic Frameworks through Direct Metal Coordination with a Phenolic Lipid Enables Diverse Applications

Energy Technology Data Exchange (ETDEWEB)

Zhu, Wei [Univ. of New Mexico, Albuquerque, NM (United States); Xiang, Guolei [Univ. of Cambridge (United Kingdom); Shang, Jin [Univ. of Hong Kong (China); Guo, Jimin [Univ. of New Mexico, Albuquerque, NM (United States); Motevalli, Benyamin [Monash Univ., Clayton, VIC (Australia); Durfee, Paul [Univ. of New Mexico, Albuquerque, NM (United States); Agola, Jacob Ongudi [Univ. of New Mexico, Albuquerque, NM (United States); Coker, Eric N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brinker, C. Jeffrey [Univ. of New Mexico, Albuquerque, NM (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2018-02-22

Here, a novel strategy for the versatile functionalization of the external surface of metal-organic frameworks (MOFs) has been developed based on the direct coordination of a phenolic-inspired lipid molecule DPGG (1,2-dipalmitoyl-sn-glycero-3-galloyl) with metal nodes/sites surrounding MOF surface. X-ray diffraction and Argon sorption analysis prove that the modified MOF particles retain their structural integrity and porosity after surface modification. Density functional theory calculations reveal that strong chelation strength between the metal sites and the galloyl head group of DPGG is the basic prerequisite for successful coating. Due to the pH-responsive nature of metal-phenol complexation, the modification process is reversible by simple washing in weak acidic water, showing an excellent regeneration ability for water-stable MOFs. Moreover, the colloidal stability of the modified MOFs in the nonpolar solvent allows them to be further organized into 2 dimensional MOF or MOF/polymer monolayers by evaporation-induced interfacial assembly conducted on an air/water interface. Lastly, the easy fusion of a second functional layer onto DPGG-modified MOF cores, enabled a series of MOF-based functional nanoarchitectures, such as MOFs encapsulated within hybrid supported lipid bilayers (so-called protocells), polyhedral core-shell structures, hybrid lipid-modified-plasmonic vesicles and multicomponent supraparticles with target functionalities, to be generated. for a wide range of applications.

Immobilization of Chlorosulfonyl-Calix[4]arene onto the surface of silica gel through the directly estrification

Science.gov (United States)

Taghvaei-Ganjali, Saeed; Zadmard, Reza; Saber-Tehrani, Mandana

2012-06-01

For the first time Chlorosulfonyl-Calix[4]arene has been chemically bonded to silica gel through the directly estrification without silane coupling agent to prepare Chlorosulfonyl-Calix[4]arene-bonded silica gel. Sample characterization was performed by various techniques such as elemental analysis, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), powder X-ray diffraction (XRD), N2 adsorption-desorption, thermal gravimetric analysis (TGA), 29Si CP/MAS spectroscopy and acid-base titration. All data approve the successful incorporation of organic group via covalent bond. From the comparison between sulfur content determined by elemental analysis and the number of H+ determined by acid-base titration, it was shown that two ester units took place onto the new synthesized sample and two acidic sites exist on the surface.

Surface Topography Hinders Bacterial Surface Motility.

Science.gov (United States)

Chang, Yow-Ren; Weeks, Eric R; Ducker, William A

2018-03-21

We demonstrate that the surface motility of the bacterium, Pseudomonas aeruginosa, is hindered by a crystalline hemispherical topography with wavelength in the range of 2-8 μm. The motility was determined by the analysis of time-lapse microscopy images of cells in a flowing growth medium maintained at 37 °C. The net displacement of bacteria over 5 min is much lower on surfaces containing 2-8 μm hemispheres than on flat topography, but displacement on the 1 μm hemispheres is not lower. That is, there is a threshold between 1 and 2 μm for response to the topography. Cells on the 4 μm hemispheres were more likely to travel parallel to the local crystal axis than in other directions. Cells on the 8 μm topography were less likely to travel across the crowns of the hemispheres and were also more likely to make 30°-50° turns than on flat surfaces. These results show that surface topography can act as a significant barrier to surface motility and may therefore hinder surface exploration by bacteria. Because surface exploration can be a part of the process whereby bacteria form colonies and seek nutrients, these results help to elucidate the mechanism by which surface topography hinders biofilm formation.

Power electronics substrate for direct substrate cooling

Science.gov (United States)

Le, Khiet [Mission Viejo, CA; Ward, Terence G [Redondo Beach, CA; Mann, Brooks S [Redondo Beach, CA; Yankoski, Edward P [Corona, CA; Smith, Gregory S [Woodland Hills, CA

2012-05-01

Systems and apparatus are provided for power electronics substrates adapted for direct substrate cooling. A power electronics substrate comprises a first surface configured to have electrical circuitry disposed thereon, a second surface, and a plurality of physical features on the second surface. The physical features are configured to promote a turbulent boundary layer in a coolant impinged upon the second surface.

Stimulated Raman signals at conical intersections: Ab initio surface hopping simulation protocol with direct propagation of the nuclear wave function

International Nuclear Information System (INIS)

Kowalewski, Markus; Mukamel, Shaul

2015-01-01

Femtosecond Stimulated Raman Spectroscopy (FSRS) signals that monitor the excited state conical intersections dynamics of acrolein are simulated. An effective time dependent Hamiltonian for two C—H vibrational marker bands is constructed on the fly using a local mode expansion combined with a semi-classical surface hopping simulation protocol. The signals are obtained by a direct forward and backward propagation of the vibrational wave function on a numerical grid. Earlier work is extended to fully incorporate the anharmonicities and intermode couplings

Stimulated Raman signals at conical intersections: Ab initio surface hopping simulation protocol with direct propagation of the nuclear wave function

Energy Technology Data Exchange (ETDEWEB)

Kowalewski, Markus, E-mail: mkowalew@uci.edu; Mukamel, Shaul, E-mail: smukamel@uci.edu [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States)

2015-07-28

Femtosecond Stimulated Raman Spectroscopy (FSRS) signals that monitor the excited state conical intersections dynamics of acrolein are simulated. An effective time dependent Hamiltonian for two C—H vibrational marker bands is constructed on the fly using a local mode expansion combined with a semi-classical surface hopping simulation protocol. The signals are obtained by a direct forward and backward propagation of the vibrational wave function on a numerical grid. Earlier work is extended to fully incorporate the anharmonicities and intermode couplings.

Directing Creativity

DEFF Research Database (Denmark)

Darsø, Lotte; Ibbotson, Piers

2008-01-01

In this article we argue that leaders facing complex challenges can learn from the arts, specifically that leaders can learn by examining how theatre directors direct creativity through creative constraints. We suggest that perceiving creativity as a boundary phenomenon is helpful for directing it....... Like leaders, who are caught in paradoxical situations where they have to manage production and logistics simultaneously with making space for creativity and innovation, theatre directors need to find the delicate balance between on one hand renewal of perceptions, acting and interaction...... and on the other hand getting ready for the opening night. We conclude that the art of directing creativity is linked to developing competencies of conscious presence, attention and vigilance, whereas the craft of directing creativity concerns communication, framing and choice....

Surface-water surveillance

Energy Technology Data Exchange (ETDEWEB)

Saldi, K.A.; Dirkes, R.L.; Blanton, M.L.

1995-06-01

This section of the 1994 Hanford Site Environmental Report summarizes the Surface water on and near the Hanford Site is monitored to determine the potential effects of Hanford operations. Surface water at Hanford includes the Columbia River, riverbank springs, ponds located on the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site. Columbia River sediments are also included in this discussion. Tables 5.3.1 and 5.3.2 summarize the sampling locations, sample types, sampling frequencies, and sample analyses included in surface-water surveillance activities during 1994. Sample locations are also identified in Figure 5.3.1. This section describes the surveillance effort and summarizes the results for these aquatic environments. Detailed analytical results are reported by Bisping (1995).

Surface-water surveillance

International Nuclear Information System (INIS)

Saldi, K.A.; Dirkes, R.L.; Blanton, M.L.

1995-01-01

This section of the 1994 Hanford Site Environmental Report summarizes the Surface water on and near the Hanford Site is monitored to determine the potential effects of Hanford operations. Surface water at Hanford includes the Columbia River, riverbank springs, ponds located on the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site. Columbia River sediments are also included in this discussion. Tables 5.3.1 and 5.3.2 summarize the sampling locations, sample types, sampling frequencies, and sample analyses included in surface-water surveillance activities during 1994. Sample locations are also identified in Figure 5.3.1. This section describes the surveillance effort and summarizes the results for these aquatic environments. Detailed analytical results are reported by Bisping (1995)

Acidic deposition: State of science and technology. Report 9. Current status of surface-water acid-base chemistry. Final report

International Nuclear Information System (INIS)

Baker, L.A.; Kaufmann, P.R.; Brakke, D.F.; Herlihy, A.T.; Eilers, J.M.

1990-09-01

The report is based largely upon the National Surface Water Survey (NSWS), augmented by numerous smaller state and university surveys and many detailed watershed studies. In describing the current status of surface waters, the authors go far beyond the description of population statistics, although some of this is necessary, and direct their attention to the interpretation of these data. They address the question of the sources of acidity to surface waters in order to determine the relative importance of acidic deposition compared with other sources, such as naturally produced organic acids and acid mine drainage. They also examine in some detail what they call 'high interest' populations-the specific groups of lakes and streams most likely to be impacted by acidic deposition. The authors then turn to the general question of uncertainty, and finally examine low alkalinity surface waters in several other parts of the world to develop further inferences about the acid-base status of surface waters in the United States

Direct metal brazing to cermet feedthroughs

International Nuclear Information System (INIS)

Hopper, A.C. Jr.

1984-01-01

An improved method for brazing metallic components to a cermet surface in an alumina substrate eliminates the prior art metallized layer over the cermet via and adjoining alumina surfaces. Instead, a nickel layer is applied over the cermet surface only and metallic components are brazed directly to this nickel coated cermet surface. As a result, heretofore unachievable tensile strength joints are produced. In addition, cermet vias with their brazed metal components can be spaced more closely in the alumina substrate because of the elimination of the prior art metallized alumina surfaces

Direct sputtering- and electro-deposition of gold coating onto the closed surface of ultralow-density carbon-hydrogen foam cylinder

Energy Technology Data Exchange (ETDEWEB)

Luo, Jiaqiu; Yin, Jialing; Zhang, Hao; Yao, Mengqi; Hu, Wencheng, E-mail: huwc@uestc.edu.cn

2016-12-15

Highlights: • The surface pores of P(DVB/St) foam cylinder are sealed by CVD method. • Gold film was deposited on the surface of foam cylinder by magnetron sputtering. • Electroless plating was excluded in the present experiments. • The gold coatings were thickened through the electrodeposition process. - Abstract: This work aimed to fabricate a gold coating on the surface of ultralow-density carbon-hydrogen foam cylinder without electroless plating. Poly (divinylbenzene/styrene) foam cylinder was synthetized by high internal phase emulsion, and chemical vapor deposition polymerization approach was used to form a compact poly-p-xylylene film on the foam cylinder. Conducting gold thin films were directly deposited onto the poly-p-xylylene-modified foam cylinder by magnetron sputtering, and electrochemical deposition was adopted to thicken the gold coatings. The micro-structures and morphologies of poly (divinylbenzene/styrene) foam cylinder and gold coating were observed by field-emission scanning electron microscopy. The gold coating content was investigated by energy-dispersive X-ray. The thicknesses of poly-p-xylylene coating and sputtered gold thin-film were approximately 500 and 100 nm, respectively. After electrochemical deposition, the thickness of gold coating increased to 522 nm, and the gold coating achieved a compact and uniform structure.

Direct mass spectrometric screening of antibiotics from bacterial surfaces using liquid extraction surface analysis.

Science.gov (United States)

Kai, Marco; González, Ignacio; Genilloud, Olga; Singh, Sheo B; Svatoš, Aleš

2012-10-30

There is a need to find new antibiotic agents to fight resistant pathogenic bacteria. To search successfully for novel antibiotics from bacteria cultivated under diverse conditions, we need a fast and cost-effective screening method. A combination of Liquid Extraction Surface Analysis (LESA), automated chip-based nanoelectrospray ionization, and high-resolution mass or tandem mass spectrometry using an Orbitrap XL was tested as the screening platform. Actinobacteria, known to produce well-recognized thiazolyl peptide antibiotics, were cultivated on a plate of solid medium and the antibiotics were extracted by organic solvent mixtures from the surface of colonies grown on the plate and analyzed using mass spectrometry (MS). LESA combined with high-resolution MS is a powerful tool with which to extract and detect thiazolyl peptide antibiotics from different Actinobacteria. Known antibiotics were correctly detected with high mass accuracy (antibiotics in particular and natural products in general. The method described in this paper is suitable for (1) screening the natural products produced by bacterial colonies on cultivation plates within the first 2 min following extraction and (2) detecting antibiotics at high mass accuracy; the cost is around 2 Euro per sample. Copyright © 2012 John Wiley & Sons, Ltd.

Demultiplexing Surface Waves With Silicon Nanoantennas

DEFF Research Database (Denmark)

Sinev, I.; Bogdanov, A.; Komissarenko, F.

2017-01-01

We demonstrate directional launching of surface plasmon polaritons on thin gold film with a single silicon nanosphere. The directivity pattern of the excited surface waves exhibits rapid switching from forward to backward excitation within extremely narrow spectral hand (! 50 nm), which is driven...... by the mutual interference of magnetic and electric dipole moments supported by the dielectric nanoantenna....

The reliability and accuracy of two methods for proximal caries detection and depth on directly visible proximal surfaces: an in vitro study

DEFF Research Database (Denmark)

Ekstrand, K R; Alloza, Alvaro Luna; Promisiero, L

2011-01-01

This study aimed to determine the reliability and accuracy of the ICDAS and radiographs in detecting and estimating the depth of proximal lesions on extracted teeth. The lesions were visible to the naked eye. Three trained examiners scored a total of 132 sound/carious proximal surfaces from 106 p...

Directed Hierarchical Patterning of Polycarbonate Bisphenol A Glass Surface along Predictable Sites

Directory of Open Access Journals (Sweden)

Mazen Khaled

2015-01-01

Full Text Available This paper reports a new approach in designing textured and hierarchical surfaces on polycarbonate bisphenol A type glass to improve hydrophobicity and dust repellent application for solar panels. Solvent- and vapor-induced crystallization of thermoplastic glass polycarbonate bisphenol A (PC is carried out to create hierarchically structured surfaces. In this approach dichloromethane (DCM and acetone are used in sequence. Samples are initially immersed in DCM liquid to generate nanopores, followed by exposing to acetone vapor resulting in the generation of hierarchical structure along the interporous sites. The effects of exposure time on the size, density, and distance of the generated spherules and gaps are studied and correlated with the optical transmittance and contact angle measurements at the surface. At optimized exposure time a contact angle of 98° was achieved with 80% optical transmittance. To further increase the hydrophobicity while maintaining optical properties, the hierarchical surfaces were coated with a transparent composite of tetraethyl orthosilicate as precursor and hexamethyldisilazane as silylation agent resulting in an average contact angle of 135.8° and transmittance of around 70%. FTIR and AFM characterization techniques are employed to study the composition and morphology of the generated surfaces.

The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka Event

Science.gov (United States)

Tegzes, A. D.; Jansen, E.; Telford, R. J.

2014-02-01

The so-called "8.2 ka Event" has been widely regarded as a major climate perturbation over the Holocene. It is most readily identifiable in the oxygen-isotope records from Greenland ice cores as an approximately 160 yr-long cold interval between 8250-8090 yr BP. The prevailing view has been that the cooling over Greenland, and potentially over the northern North Atlantic at least, was triggered by the catastrophic final drainage of the Agassiz-Ojibway proglacial lake as part of the remnant Laurentide Ice Sheet collapsed over Hudson Bay at around 8420 ± 80 yr BP. The consequent freshening of surface waters in the northern North Atlantic Ocean and the Nordic Seas resulted in weaker overturning, hence reduced northward heat transport. Here we present proxy records from site JM97-MD95-2011 on the mid-Norwegian Margin indicating a (sharp) decline in the strength of the eastern branch of the Atlantic Inflow into the Nordic Seas immediately following a uniquely large drop in (sub)surface ocean temperatures coeval with the lake outbursts. We propose that the final drainage of Lake Agassiz-Ojibway was accompanied by a major iceberg discharge from Hudson Bay, which resulted in the cooling of the northward-directed northern Gulf Stream-North Atlantic Drift-Norwegian Atlantic Current system. Since our current-strength proxy records from the mid-Norwegian Margin do not evidence an exceptionally strong reduction in the main branch of the Atlantic Inflow into the Nordic Seas at the time, we argue that a chilled northward-directed (sub)surface-current system and an already colder background climate state could be the main factors responsible for the 8.2 ka climate perturbation.

Analysis of Chloroquine and Metabolites Directly from Whole-body Animal Tissue Sections by Liquid Extraction Surface Analysis (LESA) and Tandem Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Parson, Whitney B [ORNL; Koeniger, Stormy L [Abbott Laboratories; Johnson, Robert W [Abbott Laboratories; Erickson, Jamie [Abbott Laboratories; Tian, Yu [Abbott Laboratories; Stedman, Christopher A. [Abbott Laboratories; Schwartz, Annette [Abbott Laboratories; Tarcsa, Edit [Abbott Laboratories; Cole, Roderic [ORNL; Van Berkel, Gary J [ORNL

2012-01-01

The rapid and direct analysis of the amount and spatial distribution of exogenous chloroquine and chloroquine metabolites from tissue sections by liquid extraction surface sampling analysis coupled with tandem mass spectrometry (LESA-MS) was demonstrated. LESA-MS results compared well with previously published chloroquine quantification data collected by organ excision, extraction and fluorescent detection. The ability to directly sample and analyze spatially-resolved exogenous molecules from tissue sections with minimal sample preparation and analytical method development has the potential to facilitate the assessment of target tissue penetration of pharmaceutical compounds, to establish pharmacokinetic/pharmacodynamic (PK/PD) relationships, and to complement established pharmacokinetic methods used in the drug discovery process during tissue distribution assessment.

Advanced Surface Technology

DEFF Research Database (Denmark)

Møller, Per; Nielsen, Lars Pleht

of the components. It covers everything from biocompatible surfaces of IR absorbent or reflective surfaces to surfaces with specific properties within low friction, hardness, corrosion, colors, etc. The book includes more than 400 pages detailing virtually all analysis methods for examining at surfaces.......This new significant book on advanced modern surface technology in all its variations, is aimed at both teaching at engineering schools and practical application in industry. The work covers all the significant aspects of modern surface technology and also describes how new advanced techniques make...

Electrostatic interaction between an enzyme and electrodes in the electric double layer examined in a view of direct electron transfer-type bioelectrocatalysis.

Science.gov (United States)

Sugimoto, Yu; Kitazumi, Yuki; Tsujimura, Seiya; Shirai, Osamu; Yamamoto, Masahiro; Kano, Kenji

2015-01-15

Effects of the electrode poential on the activity of an adsorbed enzyme has been examined by using copper efflux oxidase (CueO) as a model enzyme and by monitoring direct electron transfer (DET)-type bioelectrocatalysis of oxygen reduction. CueO adsorbed on bare Au electrodes at around the point of zero charge (E(pzc)) shows the highest DET activity, and the activity decreases as the adsorption potential (E(ad); at which the enzyme adsorbs) is far from E(pzc). We propose a model to explain the phenomena in which the electrostatic interaction between the enzyme and electrodes in the electric double layer affects the orientation and the stability of the adsorbed enzyme. The self-assembled monolayer of butanethiol on Au electrodes decreases the electric field in the outside of the inner Helmholtz plane and drastically diminishes the E(ad) dependence of the DET activity of CueO. When CueO is adsorbed on bare Au electrodes under open circuit potential and then is held at hold potentials (E(ho)) more positive than E(pzc), the DET activity of the CueO rapidly decreases with the hold time. The strong electric field with positive surface charge density on the metallic electrode (σ(M)) leads to fatal denaturation of the adsorbed CueO. Such denaturation effect is not so serious at E(ho)

Examination of Zircaloy-clad spent fuel after extended pool storage

International Nuclear Information System (INIS)

Bradley, E.R.; Bailey, W.J.; Johnson, A.B. Jr.; Lowry, L.M.

1981-09-01

This report presents the results from metallurgical examinations of Zircaloy-clad fuel rods from two bundles (0551 and 0074) of Shippingport PWR Core 1 blanket fuel after extended water storage. Both bundles were exposed to water in the reactor from late 1957 until discharge. The estimated average burnups were 346 GJ/kgU (4000 MWd/MTU) for bundle 0551 and 1550 GJ/kgU (18,000 MWd/MTU) for bundle 0074. Fuel rods from bundle 0551 were stored in deionized water for nearly 21 yr prior to examination in 1980, representing the world's oldest pool-stored Zircaloy-clad fuel. Bundle 0074 has been stored in deionized water since reactor discharge in 1964. Data from the current metallurgical examinations enable a direct assessment of extended pool storage effects because the metallurgical condition of similar fuel rods was investigated and documented soon after reactor discharge. Data from current and past examinations were compared, and no significant degradation of the Zircaloy cladding was indicated after almost 21 yr in water storage. The cladding dimensions and mechanical properties, fission gas release, hydrogen contents of the cladding, and external oxide film thicknesses that were measured during the current examinations were all within the range of measurements made on fuel bundles soon after reactor discharge. The appearance of the external surfaces and the microstructures of the fuel and cladding were also similar to those reported previously. In addition, no evidence of accelerated corrosion or hydride redistribution in the cladding was observed

Diversiform hybrid-polarization surface plasmon polaritons in a dielectric–metal metamaterial

Directory of Open Access Journals (Sweden)

Q. Zhang

2017-04-01

Full Text Available Hybrid-polarization surface plasmon polaritons (HSPPs at the interface between an isotropic medium and a one-dimensional metal–dielectric metamaterial (MM were discussed, where the metal-layer permittivity was described with the improved Drude model. From the obtained dispersion equations, we predicated five types of HSPPs. One type is the Dyakonov-like surface polariton and another type is the tradition-like surface polarton. The others are new types of HSPPs. We establish a numerical simulation method of the attenuated total reflection (ATR measurement to examine these HSPPs. The results from the ATR spectra are consistent with those from the dispersion equations and indicate the different polarization features of these HSPPs. The numerical results also demonstrate that the observation of each type of HSPPs requires different conditions dictated by the material parameters and the polarization direction of incident light used in the ATR spectra. These results may further widen the space of potential applications of surface plasmon polaritons.

Hydrophobic and optical characteristics of graphene and graphene oxide films transferred onto functionalized silica particles deposited glass surface

Science.gov (United States)

Yilbas, B. S.; Ibrahim, A.; Ali, H.; Khaled, M.; Laoui, T.

2018-06-01

Hydrophobic and optical transmittance characteristics of the functionalized silica particles on the glass surface prior and after transfer of graphene and graphene oxide films on the surface are examined. Nano-size silica particles are synthesized and functionalized via chemical grafting and deposited onto a glass surface. Graphene film, grown on copper substrate, was transferred onto the functionalized silica particles surface through direct fishing method. Graphene oxide layer was deposited onto the functionalized silica particles surface via spin coating technique. Morphological, hydrophobic, and optical characteristics of the functionalized silica particles deposited surface prior and after graphene and graphene oxide films transfer are examined using the analytical tools. It is found that the functionalized silica particles are agglomerated at the surface forming packed structures with few micro/nano size pores. This arrangement gives rise to water droplet contact angle and contact angle hysteresis in the order of 163° and 2°, respectively, and remains almost uniform over the entire surface. Transferring graphene and depositing graphene oxide films over the functionalized silica particles surface lowers the water droplet contact angle slightly (157-160°) and increases the contact angle hysteresis (4°). The addition of the graphene and graphene oxide films onto the surface of the deposited functionalized silica particles improves the optical transmittance.

Immobilization of Chlorosulfonyl-Calix[4]arene onto the surface of silica gel through the directly estrification

Energy Technology Data Exchange (ETDEWEB)

Taghvaei-Ganjali, Saeed, E-mail: S-taghvaei@IAU-tnb.ac.ir [Chemistry Department, Islamic Azad University, North Tehran Branch, Postal Code: 1913674711, Tehran (Iran, Islamic Republic of); Zadmard, Reza [Chemistry and Chemical Engineering Research Center of Iran, Postal Code: 1496813151, Tehran (Iran, Islamic Republic of); Saber-Tehrani, Mandana [Chemistry Department, Islamic Azad University, North Tehran Branch, Postal Code: 1913674711, Tehran (Iran, Islamic Republic of)

2012-06-01

For the first time Chlorosulfonyl-Calix[4]arene has been chemically bonded to silica gel through the directly estrification without silane coupling agent to prepare Chlorosulfonyl-Calix[4]arene-bonded silica gel. Sample characterization was performed by various techniques such as elemental analysis, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), powder X-ray diffraction (XRD), N{sub 2} adsorption-desorption, thermal gravimetric analysis (TGA), {sup 29}Si CP/MAS spectroscopy and acid-base titration. All data approve the successful incorporation of organic group via covalent bond. From the comparison between sulfur content determined by elemental analysis and the number of H{sup +} determined by acid-base titration, it was shown that two ester units took place onto the new synthesized sample and two acidic sites exist on the surface.

Shadow analysis of soil surface roughness compared to the chain set method and direct measurement of micro-relief

Directory of Open Access Journals (Sweden)

R. García Moreno

2010-08-01

Full Text Available Soil surface roughness (SSR expresses soil susceptibility to wind and water erosion and plays an important role in the development and the maintenance of soil biota. Several methods have been developed to characterise SSR based on different methods of acquiring data. Because the main problems related to these methods involve the use and handling of equipment in the field, the present study aims to fill the need for a method for measuring SSR that is more reliable, low-cost and convenient in the field than traditional field methods. Shadow analysis, which interprets micro-topographic shadows, is based on the principle that there is a direct relationship between the soil surface roughness and the shadows cast by soil structures under fixed sunlight conditions. SSR was calculated with shadows analysis in the laboratory using hemispheres of different diameter with a diverse distribution of known altitudes and a surface area of 1 m².

Data obtained from the shadow analysis were compared to data obtained with the chain method and simulation of the micro-relief. The results show a relationship among the SSR calculated using the different methods. To further improve the method, shadow analysis was used to measure the SSR in a sandy clay loam field using different tillage tools (chisel, tiller and roller and in a control of 4 m² surface plots divided into subplots of 1 m². The measurements were compared to the data obtained using the chain set and pin meter methods. The SSR measured was the highest when the chisel was used, followed by the tiller and the roller, and finally the control, for each of the three methods. Shadow analysis is shown to be a reliable method that does not disturb the measured surface, is easy to handle and analyse, and shortens the time involved in field operations by a factor ranging from 4 to 20 compared to well known techniques such as the chain set and pin meter methods.

Surface acoustic waves voltage controlled directional coupler

Science.gov (United States)

Golan, G.; Griffel, G.; Yanilov, E.; Ruschin, S.; Seidman, A.; Croitoru, N.

1988-10-01

An important condition for the development of surface wave integrated-acoustic devices is the ability to guide and control the propagation of the acoustic energy. This can be implemented by deposition of metallic "loading" channels on an anisotropic piezoelectric substrate. Deposition of such two parallel channels causes an effective coupling of acoustic energy from one channel to the other. A basic requirement for this coupling effect is the existence of the two basic modes: a symmetrical and a nonsymmetrical one. A mode map that shows the number of sustained modes as a function of the device parameters (i.e., channel width; distance between channels; material velocity; and acoustical exciting frequency) is presented. This kind of map can help significantly in the design process of such a device. In this paper we devise an advanced acoustical "Y" coupler with the ability to control its effective coupling by an externally applied voltage, thereby causing modulation of the output intensities of the signals.

Normal Isocurvature Surfaces and Special Isocurvature Circles (SIC)

Science.gov (United States)

Manoussakis, Gerassimos; Delikaraoglou, Demitris

2010-05-01

An isocurvature surface of a gravity field is a surface on which the value of the plumblines' curvature is constant. Here we are going to study the isocurvature surfaces of the Earth's normal gravity field. The normal gravity field is a symmetric gravity field therefore the isocurvature surfaces are surfaces of revolution. But even in this case the necessary relations for their study are not simple at all. Therefore to study an isocurvature surface we make special assumptions to form a vector equation which will hold only for a small coordinate patch of the isocurvature surface. Yet from the definition of the isocurvature surface and the properties of the normal gravity field is possible to express very interesting global geometrical properties of these surfaces without mixing surface differential calculus. The gradient of the plumblines' curvature function is vertical to an isocurvature surface. If P is a point of an isocurvature surface and "Φ" is the angle of the gradient of the plumblines' curvature with the equatorial plane then this direction points to the direction along which the curvature of the plumbline decreases / increases the most, and therefore is related to the strength of the normal gravity field. We will show that this direction is constant along a line of curvature of the isocurvature surface and this line is an isocurvature circle. In addition we will show that at each isocurvature surface there is at least one isocurvature circle along which the direction of the maximum variation of the plumblines' curvature function is parallel to the equatorial plane of the ellipsoid of revolution. This circle is defined as a Special Isocurvature Circle (SIC). Finally we shall prove that all these SIC lye on a special surface of revolution, the so - called SIC surface. That is to say, a SIC is not an isolated curve in the three dimensional space.

X-ray photoelectron spectroscopy studies of nitridation on 4H-SiC (0001) surface by direct nitrogen atomic source

International Nuclear Information System (INIS)

Chai, J. W.; Pan, J. S.; Zhang, Z.; Wang, S. J.; Chen, Q.; Huan, C. H. A.

2008-01-01

A Si 3 N 4 passivation layer has been successfully grown on the 4H-SiC (0001) surface by direct atomic source nitridation at various substrate temperatures. In situ x-ray photoelectron spectroscopy measurements show that higher substrate temperature leads to higher nitridation rate and good crystallinity of the passivation layer. A thin oxynitride layer on the top of the Si 3 N 4 was observed due to the residual O in the vacuum system, but was decomposed during annealing. In the meantime, excess C was found to be effectively removed by the reactive atomic N source

Surface Habitat Systems

Science.gov (United States)

Kennedy, Kriss J.

2009-01-01

The Surface Habitat Systems (SHS) Focused Investment Group (FIG) is part of the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) effort to provide a focused direction and funding to the various projects that are working on human surface habitat designs and technologies for the planetary exploration missions. The overall SHS-FIG effort focuses on directing and guiding those projects that: 1) develop and demonstrate new surface habitat system concepts, innovations, and technologies to support human exploration missions, 2) improve environmental systems that interact with human habitats, 3) handle and emplace human surface habitats, and 4) focus on supporting humans living and working in habitats on planetary surfaces. The activity areas of the SHS FIG described herein are focused on the surface habitat project near-term objectives as described in this document. The SHS-FIG effort focuses on mitigating surface habitat risks (as identified by the Lunar Surface Systems Project Office (LSSPO) Surface Habitat Element Team; and concentrates on developing surface habitat technologies as identified in the FY08 gap analysis. The surface habitat gap assessment will be updated annually as the surface architecture and surface habitat definition continues to mature. These technologies are mapped to the SHS-FIG Strategic Development Roadmap. The Roadmap will bring to light the areas where additional innovative efforts are needed to support the development of habitat concepts and designs and the development of new technologies to support of the LSSPO Habitation Element development plan. Three specific areas of development that address Lunar Architecture Team (LAT)-2 and Constellation Architecture Team (CxAT) Lunar habitat design issues or risks will be focused on by the SHS-FIG. The SHS-FIG will establish four areas of development that will help the projects prepare in their planning for surface habitat systems development. Those development areas are

Examining Model Atmospheric Particles Inside and Out

Science.gov (United States)

Wingen, L. M.; Zhao, Y.; Fairhurst, M. C.; Perraud, V. M.; Ezell, M. J.; Finlayson-Pitts, B. J.

2017-12-01

Atmospheric particles scatter incoming solar radiation and act as cloud condensation nuclei (CCN), thereby directly and indirectly affecting the earth's radiative balance and reducing visibility. These atmospheric particles may not be uniform in composition. Differences in the composition of a particle's outer surface from its core can arise during particle growth, (photo)chemical aging, and exchange of species with the gas phase. The nature of the surface on a molecular level is expected to impact growth mechanisms as well as their ability to act as CCN. Model laboratory particle systems are explored using direct analysis in real time-mass spectrometry (DART-MS), which is sensitive to surface composition, and contrasted with average composition measurements using high resolution, time-of-flight aerosol mass spectrometry (HR-ToF-AMS). Results include studies of the heterogeneous reactions of amines with solid dicarboxylic acid particles, which are shown to generate aminium dicarboxylate salts at the particle surface, leaving an unreacted core. Combination of both mass spectrometric techniques reveals a trend in reactivity of C3-C7 dicarboxylic acids with amines and allows calculation of the DART probe depth into the particles. The results of studies on additional model systems that are currently being explored will also be reported.

Surface waves on the tailward flanks of the Earth's magnetopause

Science.gov (United States)

Seon, J.; Frank, L. A.; Lazarus, A. J.; Lepping, R. P.

1995-01-01

Forty-three examples of ISEE 1 tailward flank side magnetopause crossings are examined and directly compared with upstream solar wind parameters. The crossings are classified into two groups. In the first group, a few sudden magnetopause crossings are observed, whereas repeated magnetopause crossings and oscillatory motions, often with boundary layer signatures, are observed in the second group. These distinctive characteristics of the two groups are interpreted in terms of the surface waves due to the Kelvin-Helmholtz instability. It is found that low solar wind speed tends to favor characteristics of the first group, whereas high solar wind speed yields those of the second group. However, no evident correlations between the groups and the interplanetary magnetic field directions are found.

Top-Down Proteomics and Direct Surface Sampling of Neonatal Dried Blood Spots: Diagnosis of Unknown Hemoglobin Variants

Science.gov (United States)

Edwards, Rebecca L.; Griffiths, Paul; Bunch, Josephine; Cooper, Helen J.

2012-11-01

We have previously shown that liquid microjunction surface sampling of dried blood spots coupled with high resolution top-down mass spectrometry may be used for screening of common hemoglobin variants HbS, HbC, and HbD. In order to test the robustness of the approach, we have applied the approach to unknown hemoglobin variants. Six neonatal dried blood spot samples that had been identified as variants, but which could not be diagnosed by current screening methods, were analyzed by direct surface sampling top-down mass spectrometry. Both collision-induced dissociation and electron transfer dissociation mass spectrometry were employed. Four of the samples were identified as β-chain variants: two were heterozygous Hb D-Iran, one was heterozygous Hb Headington, and one was heterozygous Hb J-Baltimore. The fifth sample was identified as the α-chain variant heterozygous Hb Phnom Penh. Analysis of the sixth sample suggested that it did not in fact contain a variant. Adoption of the approach in the clinic would require speed in both data collection and interpretation. To address that issue, we have compared manual data analysis with freely available data analysis software (ProsightPTM). The results demonstrate the power of top-down proteomics for hemoglobin variant analysis in newborn samples.

Determination of the Basic Friction Angle of Rock Surfaces by Tilt Tests

Science.gov (United States)

Jang, Hyun-Sic; Zhang, Qing-Zhao; Kang, Seong-Seung; Jang, Bo-An

2018-04-01

Samples of Hwangdeung granite from Korea and Berea sandstone from USA, both containing sliding planes, were prepared by saw-cutting or polishing using either #100 or #600 grinding powders. Their basic friction angles were measured by direct shear testing, triaxial compression testing, and tilt testing. The direct shear tests and triaxial compression tests on the saw-cut, #100, and #600 surfaces indicated that the most reliable results were obtained from the #100 surface: basic friction angle of 29.4° for granite and 34.1° for sandstone. To examine the effect of surface conditions on the friction angle in tilt tests, the sliding angles were measured 50 times with two surface conditions (surfaces cleaned and not cleaned after each measurement). The initial sliding angles were high regardless of rock type and surface conditions and decreased exponentially as measurements continued. The characteristics of the sliding angles, differences between tilt tests, and dispersion between measurements in each test indicated that #100 surface produced the most reliable basic friction angle measurement. Without cleaning the surfaces, the average angles for granite (32 measurements) and sandstone (23 measurements) were similar to the basic friction angle. When 20-50 measurements without cleaning were averaged, the basic friction angle was within ± 2° for granite and ± 3° for sandstone. Sliding angles using five different tilting speeds were measured but the average was similar, indicating that tilting speed (between 0.2° and 1.6°/s) has little effect on the sliding angle. Sliding angles using four different sample sizes were measured with the best results obtained for samples larger than 8 × 8 cm.

Comparison of Direct and Indirect Methods of Teaching Breast Self-Examination – Influence on Knowledge and Attitudes of Iranian Nursing and Midwifery Personnel

Science.gov (United States)

Shahbazi, Sara; Heidari, Mohammad; Ghafourifard, Mansour

2017-04-01

Background: Breast cancer is the most common cancer in women. Monthly breast self-examination (BSE) has been presented as one of the best screening methods available. The aim of this study was to compare effects of both direct and indirect methods of teaching of BSE on knowledge and attitudes of nursing and midwifery personnel. Materials and Methods: The present study was performed on 89 nursing and midwifery personnel in Valiasr hospital of Borujen city. Participants were randomly divided into a direct and an indirect training group. Researcher-designed BSE knowledge and attitude and demographic information questionnaires were used for data collection. Results: Before the education intervention, the mean levels of knowledge and attitude were 9.82±2.79 and 56.5±6.21 in the direct training group and 9.59±2.71 and 54.5±4.51 in the indirect training group; after the intervention, they reached 19.2±0.96 and 62.9±4.21, and 11.0±2.58 and 59.0±3.44, respectively. The difference in the mean levels of knowledge and attitude were significantly higher in the direct training group post intervention (Pdirect training methods. Creative Commons Attribution License

Recovery of Vanadium from Magnetite Ore Using Direct Acid Leaching: Optimization of Parameters by Plackett-Burman and Response Surface Methodologies

Science.gov (United States)

Nejad, Davood Ghoddocy; Khanchi, Ali Reza; Taghizadeh, Majid

2018-06-01

Recovery of vanadium from magnetite ore by direct acid leaching is discussed. The proposed process, which employs a mixture of nitric and sulfuric acids, avoids pyrometallurgical treatments since such treatment consumes a high amount of energy. To determine the optimum conditions of vanadium recovery, the leaching process is optimized through Plackett-Burman (P-B) design and response surface methodology (RSM). In this respect, temperature (80-95°C), liquid to solid ratio (L/S) (3-10 mL g-1), sulfuric acid concentration (3-6 M), nitric acid concentration (5-10 vol.%) and time (4-8 h) are considered as the independent variables. According to the P-B approach, temperature and acid concentrations are, respectively, the most effective parameters in the leaching process. These parameters are optimized using RSM to maximize recovery of vanadium by direct acid leaching. In this way, 86.7% of vanadium can be extracted from magnetic ore.

Performance of a commercial backscatter instrument adapted for noncontacting areal density measurements on small-diameter surfaces

International Nuclear Information System (INIS)

Higgins, P.B.

1980-12-01

Measuring the local areal density of a sensitive explosive deposited on a small-diameter surface requires noncontacting technique and good resolution. The side effects of spacing the sensing platen of an NX-500 Betascope 2.54 mm from the surface of cylinders as small as 13-mm diameter are examined. Resolution in two directions and offset error sensitivity of the system are defined and determined using coatings of simulated explosive. An eddy-current system is described which can be easily added to reduce offset errors caused by fixture misalignment

The experimental study on positioning of the surface coil for magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, Kyoji; Yotsui, Yoritaka; Koseki, Yonoshin [Osaka Dental Univ., Hirakata (Japan)

2002-12-01

We examined the correlation between signal intensity and setting angulations for magnetic resonance imagesobtained using a surface coil, which had a three inch surface coil, and dual coil, which and a three inch surface coil and an anterior neck coil. We took T2-3D weighted, T2-2D weighted and T1-2D weighted images with the angulated three-inch surface coil at 0-90 degrees with the magnetic direction. In every sequence, the maximum intensity with the dual coil was taken with angulations of 50-60 degrees. The intensity of the dual coil could be as much as the three times that of the single coil. As the angulations increased with the dual coil, the thickness of the effective intensity was decreased until it reached 50% of the maximum thickness. With the single coil it decreased until it reached 10%. When using a high-resolution coil that cannot be setup parallel with the magnetic direction, we recommend using a dual coil rather than a single coil to increase the signal intensity. In the oral cavity, the intraoral coil should be used with the extraoral coil as the phased array coil. This is the optimum condition of coil angulation for taking high resolution images. (author)

High-resolution computer-generated reflection holograms with three-dimensional effects written directly on a silicon surface by a femtosecond laser.

Science.gov (United States)

Wædegaard, Kristian J; Balling, Peter

2011-02-14

An infrared femtosecond laser has been used to write computer-generated holograms directly on a silicon surface. The high resolution offered by short-pulse laser ablation is employed to write highly detailed holograms with resolution up to 111 kpixels/mm2. It is demonstrated how three-dimensional effects can be realized in computer-generated holograms. Three-dimensional effects are visualized as a relative motion between different parts of the holographic reconstruction, when the hologram is moved relative to the reconstructing laser beam. Potential security applications are briefly discussed.

Direct and semi-direct aerosol radiative effect on the Mediterranean climate variability using a coupled regional climate system model

Science.gov (United States)

Nabat, Pierre; Somot, Samuel; Mallet, Marc; Sevault, Florence; Chiacchio, Marc; Wild, Martin

2015-02-01

A fully coupled regional climate system model (CNRM-RCSM4) has been used over the Mediterranean region to investigate the direct and semi-direct effects of aerosols, but also their role in the radiation-atmosphere-ocean interactions through multi-annual ensemble simulations (2003-2009) with and without aerosols and ocean-atmosphere coupling. Aerosols have been taken into account in CNRM-RCSM4 through realistic interannual monthly AOD climatologies. An evaluation of the model has been achieved, against various observations for meteorological parameters, and has shown the ability of CNRM-RCSM4 to reproduce the main patterns of the Mediterranean climate despite some biases in sea surface temperature (SST), radiation and cloud cover. The results concerning the aerosol radiative effects show a negative surface forcing on average because of the absorption and scattering of the incident radiation. The SW surface direct effect is on average -20.9 Wm-2 over the Mediterranean Sea, -14.7 Wm-2 over Europe and -19.7 Wm-2 over northern Africa. The LW surface direct effect is weaker as only dust aerosols contribute (+4.8 Wm-2 over northern Africa). This direct effect is partly counterbalanced by a positive semi-direct radiative effect over the Mediterranean Sea (+5.7 Wm-2 on average) and Europe (+5.0 Wm-2) due to changes in cloud cover and atmospheric circulation. The total aerosol effect is consequently negative at the surface and responsible for a decrease in land (on average -0.4 °C over Europe, and -0.5 °C over northern Africa) and sea surface temperature (on average -0.5 °C for the Mediterranean SST). In addition, the latent heat loss is shown to be weaker (-11.0 Wm-2) in the presence of aerosols, resulting in a decrease in specific humidity in the lower troposphere, and a reduction in cloud cover and precipitation. Simulations also indicate that dust aerosols warm the troposphere by absorbing solar radiation, and prevent radiation from reaching the surface, thus

Innovative tool of direct marketing

OpenAIRE

T.S. Maksymova

2010-01-01

The aspects of direct marketing activation on the basis of interactive applications introduction are examined. Basic advantages, linked with the use of the integrated marketing communications during formation of direct marketing strategies are open up.

EXAMINATION ABOUT INFLUENCE FOR PRECISION OF 3D IMAGE MEASUREMENT FROM THE GROUND CONTROL POINT MEASUREMENT AND SURFACE MATCHING

Directory of Open Access Journals (Sweden)

T. Anai

2015-05-01

Full Text Available As the 3D image measurement software is now widely used with the recent development of computer-vision technology, the 3D measurement from the image is now has acquired the application field from desktop objects as wide as the topography survey in large geographical areas. Especially, the orientation, which used to be a complicated process in the heretofore image measurement, can be now performed automatically by simply taking many pictures around the object. And in the case of fully textured object, the 3D measurement of surface features is now done all automatically from the orientated images, and greatly facilitated the acquisition of the dense 3D point cloud from images with high precision. With all this development in the background, in the case of small and the middle size objects, we are now furnishing the all-around 3D measurement by a single digital camera sold on the market. And we have also developed the technology of the topographical measurement with the air-borne images taken by a small UAV [1~5]. In this present study, in the case of the small size objects, we examine the accuracy of surface measurement (Matching by the data of the experiments. And as to the topographic measurement, we examine the influence of GCP distribution on the accuracy by the data of the experiments. Besides, we examined the difference of the analytical results in each of the 3D image measurement software. This document reviews the processing flow of orientation and the 3D measurement of each software and explains the feature of the each software. And as to the verification of the precision of stereo-matching, we measured the test plane and the test sphere of the known form and assessed the result. As to the topography measurement, we used the air-borne image data photographed at the test field in Yadorigi of Matsuda City, Kanagawa Prefecture JAPAN. We have constructed Ground Control Point which measured by RTK-GPS and Total Station. And we show the results

Examination about Influence for Precision of 3d Image Measurement from the Ground Control Point Measurement and Surface Matching

Science.gov (United States)

Anai, T.; Kochi, N.; Yamada, M.; Sasaki, T.; Otani, H.; Sasaki, D.; Nishimura, S.; Kimoto, K.; Yasui, N.

2015-05-01

As the 3D image measurement software is now widely used with the recent development of computer-vision technology, the 3D measurement from the image is now has acquired the application field from desktop objects as wide as the topography survey in large geographical areas. Especially, the orientation, which used to be a complicated process in the heretofore image measurement, can be now performed automatically by simply taking many pictures around the object. And in the case of fully textured object, the 3D measurement of surface features is now done all automatically from the orientated images, and greatly facilitated the acquisition of the dense 3D point cloud from images with high precision. With all this development in the background, in the case of small and the middle size objects, we are now furnishing the all-around 3D measurement by a single digital camera sold on the market. And we have also developed the technology of the topographical measurement with the air-borne images taken by a small UAV [1~5]. In this present study, in the case of the small size objects, we examine the accuracy of surface measurement (Matching) by the data of the experiments. And as to the topographic measurement, we examine the influence of GCP distribution on the accuracy by the data of the experiments. Besides, we examined the difference of the analytical results in each of the 3D image measurement software. This document reviews the processing flow of orientation and the 3D measurement of each software and explains the feature of the each software. And as to the verification of the precision of stereo-matching, we measured the test plane and the test sphere of the known form and assessed the result. As to the topography measurement, we used the air-borne image data photographed at the test field in Yadorigi of Matsuda City, Kanagawa Prefecture JAPAN. We have constructed Ground Control Point which measured by RTK-GPS and Total Station. And we show the results of analysis made

30 CFR 256.71 - Directional drilling.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Directional drilling. 256.71 Section 256.71... drilling. In accordance with an approved exploration plan or development and production plan, a lease may be maintained in force by directional wells drilled under the leased area from surface locations on...

Characterization of Polyethylene-Graft-Sulfonated Polyarylsulfone Proton Exchange Membranes for Direct Methanol Fuel Cell Applications.

Science.gov (United States)

Kim, Hyung Kyu; Zhang, Gang; Nam, Changwoo; Chung, T C Mike

2015-12-04

This paper examines polymer film morphology and several important properties of polyethylene-graft-sulfonated polyarylene ether sulfone (PE-g-s-PAES) proton exchange membranes (PEMs) for direct methanol fuel cell applications. Due to the extreme surface energy differences between a semi-crystalline and hydrophobic PE backbone and several amorphous and hydrophilic s-PAES side chains, the PE-g-s-PAES membrane self-assembles into a unique morphology, with many proton conductive s-PAES channels embedded in the stable and tough PE matrix and a thin hydrophobic PE layer spontaneously formed on the membrane surfaces. In the bulk, these membranes show good mechanical properties (tensile strength >30 MPa, Young's modulus >1400 MPa) and low water swelling (λ 3 mmol/g in the s-PAES domains. On the surface, the thin hydrophobic and semi-crystalline PE layer shows some unusual barrier (protective) properties. In addition to exhibiting higher through-plane conductivity (up to 160 mS/cm) than in-plane conductivity, the PE surface layer minimizes methanol cross-over from anode to cathode with reduced fuel loss, and stops the HO• and HO₂• radicals, originally formed at the anode, entering into PEM matrix. Evidently, the thin PE surface layer provides a highly desirable protecting layer for PEMs to reduce fuel loss and increase chemical stability. Overall, the newly developed PE-g-s-PAES membranes offer a desirable set of PEM properties, including conductivity, selectivity, mechanical strength, stability, and cost-effectiveness for direct methanol fuel cell applications.

Direct examination of cadmium bonding in rat tissues dosed with mine wastes and cadmium-containing solutions

International Nuclear Information System (INIS)

Diacomanolis, V.; Ng, J. C.; Sadler, R.; Harris, H. H.; Nomura, M.; Noller, B. N.

2010-01-01

Direct examination by XANES and EXAFS of metal bonding in tissue can be demonstrated by examining cadmium uptake and bonding in animal tissue maintained at cryogenic temperatures. XANES at the K-edge of cadmium were collected at the Photon Factory Advanced Ring (PF-AR), NW10A beam line at KEK-Tsukuba-Japan. Rats fed with 1g mine waste containing 8-400 mg/kg cadmium per 200g body weight (b.w.) or dosed by oral gavage with either cadmium chloride solution alone (at 6 mg/kg b.w.) or in combination with other salts (As, Cu or Zn), 5 days/week for 6 weeks, had 0.1-7.5 and 8-86 mg/kg cadmium in the liver or kidney, respectively. Rats given intraperitoneally (ip) or intravenously (iv) 1-4 times with 1 mg/kg b.w. cadmium solution had 30-120 mg/kg cadmium in the liver or kidney. Tissues from rats were kept and transferred at cryogenic temperature and XANES were recorded at 20 K. The spectra for rat liver samples suggested conjugation of cadmium with glutathione or association with the sulfide bond (Cd-S) of proteins and peptides. EXAFS of rat liver fed by Cd and Zn solutions showed that Cd was clearly bound to S ligands with an inter-atomic distance of 2.54 A ring for Cd-S that was similar to cadmium sulfide with an inter-atomic distance of 2.52 A ring for Cd-S. Liver or kidney of rats fed with mine wastes did not give an edge in the XANES spectra indicating little uptake of cadmium by the animals. Longer and higher dosing regimen may be required in order to observe the same Cd-S bond in the rat tissue from mine wastes, including confirmation by EXAFS.

Direct site-directed photocoupling of proteins onto surfaces coated with β-cyclodextrins

DEFF Research Database (Denmark)

Städe, Lars W; Wimmer, Reinhard; Stensballe, Allan

2010-01-01

. Insertion of pBpa was verified by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectroscopy. A molecular dynamic simulation, with water as solvent, showed high solvent accessibility of the pBpa benzophenone group in N27pBpa-cutinase mutant. The formation of an inclusion......A method called Dock'n'Flash was developed to offer site-specific capture and direct UVA-induced photocoupling of recombinant proteins. The method involves the tagging of recombinant proteins with photoreactive p-benzoyl-L-phenylalanine (pBpa) by genetic engineering. The photoreactive pBpa tag...... is used for affinity capture of the recombinant protein by beta-cyclodextrin (beta-CD), which provides hydrogen atoms to be abstracted in the photocoupling process. To exemplify the method, a recombinant, folded, and active N27pBpa mutant of cutinase from Fusarium solani pisi was produced in E. coli...

Springback Simulation and Tool Surface Compensation Algorithm for Sheet Metal Forming

International Nuclear Information System (INIS)

Shen Guozhe; Hu Ping; Zhang Xiangkui; Chen Xiaobin; Li Xiaoda

2005-01-01

Springback is an unquenchable forming defect in the sheet metal forming process. How to calculate springback accurately is a big challenge for a lot of FEA software. Springback compensation makes the stamped final part accordant with the designed part shape by modifying tool surface, which depends on the accurate springback amount. How ever, the meshing data based on numerical simulation is expressed by nodes and elements, such data can not be supplied directly to tool surface CAD data. In this paper, a tool surface compensation algorithm based on numerical simulation technique of springback process is proposed in which the independently developed dynamic explicit springback algorithm (DESA) is used to simulate springback amount. When doing the tool surface compensation, the springback amount of the projected point can be obtained by interpolation of the springback amount of the projected element nodes. So the modified values of tool surface can be calculated reversely. After repeating the springback and compensation calculations for 1∼3 times, the reasonable tool surface mesh is gained. Finally, the FEM data on the compensated tool surface is fitted into the surface by CAD modeling software. The examination of a real industrial part shows the validity of the present method

The control mechanism of surface traps on surface charge behavior in alumina-filled epoxy composites

International Nuclear Information System (INIS)

Li, Chuanyang; Hu, Jun; Lin, Chuanjie; He, Jinliang

2016-01-01

To investigate the role surface traps play in the charge injection and transfer behavior of alumina-filled epoxy composites, surface traps with different trap levels are introduced by different surface modification methods which include dielectric barrier discharges plasma, direct fluorination, and Cr 2 O 3 coating. The resulting surface physicochemical characteristics of experimental samples were observed using atomic force microscopy, scanning electron microscopy and fourier transform infrared spectroscopy. The surface potential under dc voltage was detected and the trap level distribution was measured. The results suggest that the surface morphology of the experimental samples differs dramatically after treatment with different surface modification methods. Different surface trap distributions directly determine the charge injection and transfer property along the surface. Shallow traps with trap level of 1.03–1.11 eV and 1.06–1.13 eV introduced by plasma and fluorination modifications are conducive for charge transport along the insulating surface, and the surface potential can be modified, producing a smoother potential curve. The Cr 2 O 3 coating can introduce a large number of deep traps with energy levels ranging from 1.09 to 1.15 eV. These can prevent charge injection through the reversed electric field formed by intensive trapped charges in the Cr 2 O 3 coatings. (paper)

Smooth polyhedral surfaces

KAUST Repository

Gü nther, Felix; Jiang, Caigui; Pottmann, Helmut

2017-01-01

Polyhedral surfaces are fundamental objects in architectural geometry and industrial design. Whereas closeness of a given mesh to a smooth reference surface and its suitability for numerical simulations were already studied extensively, the aim of our work is to find and to discuss suitable assessments of smoothness of polyhedral surfaces that only take the geometry of the polyhedral surface itself into account. Motivated by analogies to classical differential geometry, we propose a theory of smoothness of polyhedral surfaces including suitable notions of normal vectors, tangent planes, asymptotic directions, and parabolic curves that are invariant under projective transformations. It is remarkable that seemingly mild conditions significantly limit the shapes of faces of a smooth polyhedral surface. Besides being of theoretical interest, we believe that smoothness of polyhedral surfaces is of interest in the architectural context, where vertices and edges of polyhedral surfaces are highly visible.

Smooth polyhedral surfaces

KAUST Repository

Günther, Felix

2017-03-15

Polyhedral surfaces are fundamental objects in architectural geometry and industrial design. Whereas closeness of a given mesh to a smooth reference surface and its suitability for numerical simulations were already studied extensively, the aim of our work is to find and to discuss suitable assessments of smoothness of polyhedral surfaces that only take the geometry of the polyhedral surface itself into account. Motivated by analogies to classical differential geometry, we propose a theory of smoothness of polyhedral surfaces including suitable notions of normal vectors, tangent planes, asymptotic directions, and parabolic curves that are invariant under projective transformations. It is remarkable that seemingly mild conditions significantly limit the shapes of faces of a smooth polyhedral surface. Besides being of theoretical interest, we believe that smoothness of polyhedral surfaces is of interest in the architectural context, where vertices and edges of polyhedral surfaces are highly visible.

Pore sub-features reproducibility in direct microscopic and Livescan images--their reliability in personal identification.

Science.gov (United States)

Gupta, Abhishek; Sutton, Raul

2010-07-01

Third level features have been reported to have equal discriminatory power as second level details in establishing personal identification. Pore area, as an extended set third level sub-feature, has been studied by minimizing possible factors that could affect pore size. The reproducibility of pore surface area has been studied using direct microscopic and 500 ppi Livescan images. Direct microscopic pore area measurements indicated that the day on which the pore area was measured had a significant impact on the measured pore area. Pore area measurement was shown to be difficult to estimate in 500 ppi Livescan measurements owing to lack of resolution. It is not possible to reliably use pore area as an identifying feature in fingerprint examination.

Surface Waves on Metamaterials Interfaces

DEFF Research Database (Denmark)

Takayama, Osamu; Shkondin, Evgeniy; Panah, Mohammad Esmail Aryaee

2016-01-01

We analyze surface electromagnetic waves supported at the interface between isotropic medium and effective anisotropic material that can be realized by alternating conductive and dielectrics layers. This configuration can host various types of surface waves and therefore can serve as a rich...... platform for applications of surface photonics. Most of these surface waves are directional and as such their propagation can be effectively controlled by changing wavelength or material parameters tuning....

Going direct to the consumer: Examining treatment preferences for veterans with insomnia, PTSD, and depression.

Science.gov (United States)

Gutner, Cassidy A; Pedersen, Eric R; Drummond, Sean P A

2018-05-01

Inclusion of consumer preferences to disseminate evidence-based psychosocial treatment (EBPT) is crucial to effectively bridge the science-to-practice quality chasm. We examined this treatment gap for insomnia, posttraumatic stress disorder (PTSD), depression, and comorbid symptoms in a sample of 622 young adult veterans through preference in symptom focus, treatment modality, and related gender differences among those screening positive for each problem. Data were collected from veteran drinkers recruited through targeted Facebook advertisements as part of a brief online alcohol intervention. Analyses demonstrated that veterans reported greater willingness to seek insomnia-focused treatment over PTSD- or depression-focused care. Notably, even when participants screened negative for insomnia, they preferred sleep-focused care to PTSD- or depression-focused care. Although one in five veterans with a positive screen would not consider care, veterans screening for both insomnia and PTSD who would consider care had a preference for in-person counseling, and those screening for both insomnia and depression had similar preferences for in-person and mobile app-based/computer self-help treatment. Marginal gender differences were found. Incorporating direct-to-consumer methods into research can help educate stakeholders about methods to expand EBPT access. Though traditional in-person counseling was often preferred, openness to app-based/computer interventions offers alternative methods to provide veterans with EBPTs. Published by Elsevier B.V.

Design of a surface-scanning coil detector for direct bacteria detection on food surfaces using a magnetoelastic biosensor

Science.gov (United States)

Chai, Yating; Wikle, Howard C.; Wang, Zhenyu; Horikawa, Shin; Best, Steve; Cheng, Zhongyang; Dyer, Dave F.; Chin, Bryan A.

2013-09-01

The real-time, in-situ bacteria detection on food surfaces was achieved by using a magnetoelastic biosensor combined with a surface-scanning coil detector. This paper focuses on the coil design for signal optimization. The coil was used to excite the sensor's vibration and detect its resonant frequency signal. The vibrating sensor creates a magnetic flux change around the coil, which then produces a mutual inductance. In order to enhance the signal amplitude, a theory of the sensor's mutual inductance with the measurement coil is proposed. Both theoretical calculations and experimental data showed that the working length of the coil has a significant effect on the signal amplitude. For a 1 mm-long sensor, a coil with a working length of 1.3 mm showed the best signal amplitude. The real-time detection of Salmonella bacteria on a fresh food surface was demonstrated using this new technology.

Surface proteins and the formation of biofilms by Staphylococcus aureus.

Science.gov (United States)

Kim, Sung Joon; Chang, James; Rimal, Binayak; Yang, Hao; Schaefer, Jacob

2018-03-01

Staphylococcus aureus biofilms pose a serious clinical threat as reservoirs for persistent infections. Despite this clinical significance, the composition and mechanism of formation of S. aureus biofilms are unknown. To address these problems, we used solid-state NMR to examine S. aureus (SA113), a strong biofilm-forming strain. We labeled whole cells and cell walls of planktonic cells, young biofilms formed for 12-24h after stationary phase, and more mature biofilms formed for up to 60h after stationary phase. All samples were labeled either by (i) [ 15 N]glycine and l-[1- 13 C]threonine, or in separate experiments, by (ii) l-[2- 13 C, 15 N]leucine. We then measured 13 C- 15 N direct bonds by C{N} rotational-echo double resonance (REDOR). The increase in peptidoglycan stems that have bridges connected to a surface protein was determined directly by a cell-wall double difference (biofilm REDOR difference minus planktonic REDOR difference). This procedure eliminates errors arising from differences in 15 N isotopic enrichments and from the routing of 13 C label from threonine degradation to glycine. For both planktonic cells and the mature biofilm, 20% of pentaglycyl bridges are not cross-linked and are potential surface-protein attachment sites. None of these sites has a surface protein attached in the planktonic cells, but one-fourth have a surface protein attached in the mature biofilm. Moreover, the leucine-label shows that the concentration of β-strands in leucine-rich regions doubles in the mature biofilm. Thus, a primary event in establishing a S. aureus biofilm is extensive decoration of the cell surface with surface proteins that are linked covalently to the cell wall and promote cell-cell adhesion. Copyright © 2017 Elsevier B.V. All rights reserved.

Examination of material manufactured by direct metal laser sintering (DMLS

Directory of Open Access Journals (Sweden)

J. Dobránsky

2015-07-01

Full Text Available This article is concerned with assessing microstructural properties of metal component manufactured by additive DMLS technology. Two series of samples were assessed. The first one was manufactured without heat treatment. Samples in the second series were treated with heat in order to assess increase in hardness and influence on modification of microstructure. Subsequently, values of hardness were measured by Vickers Hardness Test and modification of microstructure was observed by optical microscope. Evaluations were carried out in three planes in order to assess the differences in layering of material during its processing. Differences in values of hardness and microstructural components were discovered by examination of changes in three planes.

Surface modification of polyester biomaterials for tissue engineering

International Nuclear Information System (INIS)

Jiao Yanpeng; Cui Fuzhai

2007-01-01

Surfaces play an important role in a biological system for most biological reactions occurring at surfaces and interfaces. The development of biomaterials for tissue engineering is to create perfect surfaces which can provoke specific cellular responses and direct new tissue regeneration. The improvement in biocompatibility of biomaterials for tissue engineering by directed surface modification is an important contribution to biomaterials development. Among many biomaterials used for tissue engineering, polyesters have been well documented for their excellent biodegradability, biocompatibility and nontoxicity. However, poor hydrophilicity and the lack of natural recognition sites on the surface of polyesters have greatly limited their further application in the tissue engineering field. Therefore, how to introduce functional groups or molecules to polyester surfaces, which ideally adjust cell/tissue biological functions, becomes more and more important. In this review, recent advances in polyester surface modification and their applications are reviewed. The development of new technologies or methods used to modify polyester surfaces for developing their biocompatibility is introduced. The results of polyester surface modifications by surface morphological modification, surface chemical group/charge modification, surface biomacromolecule modification and so on are reported in detail. Modified surface properties of polyesters directly related to in vitro/vivo biological performances are presented as well, such as protein adsorption, cell attachment and growth and tissue response. Lastly, the prospect of polyester surface modification is discussed, especially the current conception of biomimetic and molecular recognition. (topical review)

Development of the apparatus for measuring magnetic properties of electrical steel sheets in arbitrary directions under compressive stress normal to their surface

Science.gov (United States)

Maeda, Yoshitaka; Urata, Shinya; Nakai, Hideo; Takeuchi, Yuuya; Yun, Kyyoul; Yanase, Shunji; Okazaki, Yasuo

2017-05-01

In designing motors, one must grasp the magnetic properties of electrical steel sheets considering actual conditions in motors. Especially important is grasping the stress dependence of magnetic power loss. This paper describes a newly developed apparatus to measure two-dimensional (2-D) magnetic properties (properties under the arbitrary alternating and the rotating flux conditions) of electrical steel sheets under compressive stress normal to the sheet surface. The apparatus has a 2-D magnetic excitation circuit to generate magnetic fields in arbitrary directions in the evaluation area. It also has a pressing unit to apply compressive stress normal to the sheet surface. During measurement, it is important to apply uniform stress throughout the evaluation area. Therefore, we have developed a new flux density sensor using needle probe method. It is composed of thin copper foils sputtered on electrical steel sheets. By using this sensor, the stress can be applied to the surface of the specimen without influence of this sensor. This paper described the details of newly developed apparatus with this sensor, and measurement results of iron loss by using are shown.

Rapid and Direct VHH and Target Identification by Staphylococcal Surface Display Libraries

Directory of Open Access Journals (Sweden)

Marco Cavallari

2017-07-01

Full Text Available Unbiased and simultaneous identification of a specific antibody and its target antigen has been difficult without prior knowledge of at least one interaction partner. Immunization with complex mixtures of antigens such as whole organisms and tissue extracts including tumoral ones evokes a highly diverse immune response. During such a response, antibodies are generated against a variety of epitopes in the mixture. Here, we propose a surface display design that is suited to simultaneously identify camelid single domain antibodies and their targets. Immune libraries of single-domain antigen recognition fragments from camelid heavy chain-only antibodies (VHH were attached to the peptidoglycan of Gram-positive Staphylococcus aureus employing its endogenous housekeeping sortase enzyme. The sortase transpeptidation reaction covalently attached the VHH to the bacterial peptidoglycan. The reversible nature of the reaction allowed the recovery of the VHH from the bacterial surface and the use of the VHH in downstream applications. These staphylococcal surface display libraries were used to rapidly identify VHH as well as their targets by immunoprecipitation (IP. Our novel bacterial surface display platform was stable under harsh screening conditions, allowed fast target identification, and readily permitted the recovery of the displayed VHH for downstream analysis.

Fermi surface contours obtained from scanning tunneling microscope images around surface point defects

International Nuclear Information System (INIS)

Khotkevych-Sanina, N V; Kolesnichenko, Yu A; Van Ruitenbeek, J M

2013-01-01

We present a theoretical analysis of the standing wave patterns in scanning tunneling microscope (STM) images, which occur around surface point defects. We consider arbitrary dispersion relations for the surface states and calculate the conductance for a system containing a small-size tunnel contact and a surface impurity. We find rigorous theoretical relations between the interference patterns in the real-space STM images, their Fourier transforms and the Fermi contours of two-dimensional electrons. We propose a new method for reconstructing Fermi contours of surface electron states, directly from the real-space STM images around isolated surface defects. (paper)