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Sample records for surface morphology characterization

  1. Facet Model and Mathematical Morphology for Surface Characterization

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-11-13

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-19

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

  4. Characterization of the Surface Morphology of Bacillus Spores by Atomic Force Microscopy

    National Research Council Canada - National Science Library

    Zolock, Ruth

    2002-01-01

    The surface morphology of Bacillus spores was resolved by atomic force microscopy in order to determine if characteristic surface features could be used to distinguish between closely related species...

  5. Quantitative characterization of the influence of the nanoscale morphology of nanostructured surfaces on bacterial adhesion and biofilm formation.

    Directory of Open Access Journals (Sweden)

    Ajay Vikram Singh

    Full Text Available Bacterial infection of implants and prosthetic devices is one of the most common causes of implant failure. The nanostructured surface of biocompatible materials strongly influences the adhesion and proliferation of mammalian cells on solid substrates. The observation of this phenomenon has led to an increased effort to develop new strategies to prevent bacterial adhesion and biofilm formation, primarily through nanoengineering the topology of the materials used in implantable devices. While several studies have demonstrated the influence of nanoscale surface morphology on prokaryotic cell attachment, none have provided a quantitative understanding of this phenomenon. Using supersonic cluster beam deposition, we produced nanostructured titania thin films with controlled and reproducible nanoscale morphology respectively. We characterized the surface morphology; composition and wettability by means of atomic force microscopy, X-ray photoemission spectroscopy and contact angle measurements. We studied how protein adsorption is influenced by the physico-chemical surface parameters. Lastly, we characterized Escherichia coli and Staphylococcus aureus adhesion on nanostructured titania surfaces. Our results show that the increase in surface pore aspect ratio and volume, related to the increase of surface roughness, improves protein adsorption, which in turn downplays bacterial adhesion and biofilm formation. As roughness increases up to about 20 nm, bacterial adhesion and biofilm formation are enhanced; the further increase of roughness causes a significant decrease of bacterial adhesion and inhibits biofilm formation. We interpret the observed trend in bacterial adhesion as the combined effect of passivation and flattening effects induced by morphology-dependent protein adsorption. Our findings demonstrate that bacterial adhesion and biofilm formation on nanostructured titanium oxide surfaces are significantly influenced by nanoscale morphological

  6. 2.5D constructs for characterizing phase separated polymer blend surface morphology in tissue engineering scaffolds.

    Science.gov (United States)

    Marszalek, Jolanta E; Simon, Carl G; Thodeti, Charles; Adapala, Ravi Kumar; Murthy, Ananth; Karim, Alamgir

    2013-05-01

    Previously, we used 2D films to identify an annealed PCL-PDLLA phase-separated blend morphology which provided nanoscale surface texture and patterning that stimulated osteoblast differentiation. In order to translate these 2D surface nanopatterning effects to the walls of 3D salt-leached scaffolds, the blend phase morphology of scaffold walls must be characterized. For salt-leached scaffolds, NaCl is used as a porogen, which may affect phase separation in PCL-PDLLA blends. However, it is not possible to characterize the surface blend morphology of 3D scaffold walls using standard approaches such as AFM or optical microscopy, since scaffolds are too rough for AFM and do not transmit light for optical microscopy. We introduce a 2.5D approach that mimics the processing conditions of 3D salt-leached scaffolds, but has a geometry amenable to surface characterization by AFM and optical microscopy. For the 2.5D approach, PCL-PDLLA blend films were covered with NaCl crystals prior to annealing. The presence of NaCl significantly influenced blend morphology in PCL-PDLLA 2.5D constructs causing increased surface roughness, higher percent PCL area on the surface and a smaller PCL domain size. During cell culture on 2.5D constructs, osteoblast (MC3T3-E1) and dermal endothelial cell (MDEC) adhesion were enhanced on PCL-PDLLA blends that were annealed with NaCl while chondrogenic cell (ATDC5) adhesion was diminished. This work introduces a 2.5D approach that mimicked 3D salt-leached scaffold processing, but enabled characterization of scaffold surface properties by AFM and light microscopy, to demonstrate that the presence of NaCl during annealing strongly influenced polymer blend surface morphology and cell adhesion. Copyright © 2012 Wiley Periodicals, Inc.

  7. Surface morphological, mechanical and thermal characterization of electron beam irradiated fibers

    International Nuclear Information System (INIS)

    Choi, Hae Young; Han, Seong Ok; Lee, Jung Soon

    2008-01-01

    The surface morphology of henequen irradiated by electron beam has been investigated by atomic force microscopy (AFM). Also, the extents to which electron beam irradiation affected the tensile and thermal properties of henequen fiber were investigated with Instron tensile tests and thermogravimetric analysis (TGA). The AFM studies showed that the pectin, waxy and primary layers (P) of henequen fiber, which have heterogeneous structures, were removed from the fiber surface by electron beam irradiation. The tensile strength and thermal stability of henequen fiber decreased with increasing dose of electron beam. At the irradiation of 10 kGy, the surface roughness increased because of the removal of the pectin, waxy and P layer, but the tensile strength of henequen irradiated with 10 kGy were maintained. It has been suggested that the use of a 10 kGy dose of electron beam to modify the henequen fiber surface can improve the surface properties and preserve the fibers' mechanical and thermal properties.

  8. Control and Characterization of Titanium Dioxide Morphology: Applications in Surface Organometallic Chemistry

    KAUST Repository

    Jeantelot, Gabriel

    2014-05-01

    Surface Organometallic Chemistry leads to the combination of the high activity and specificity of homogeneous catalysts with the recoverability and practicality of heterogeneous catalysts. Most metal complexes used in this chemistry are grafted on metal oxide supports such as amorphous silica (SiO2) and γ-alumina (Al2O3). In this thesis, we sought to enable the use of titania (TiO2) as a new support for single-site well-defined grafting of metal complexes. This was achieved by synthesizing a special type of anatase-TiO2, bearing a high density of identical hydroxyl groups, through hydrothermal synthesis then post-treatment under high vacuum followed by oxygen flow, and characterized by several analytical techniques including X-ray diffraction, transmission electron microscopy, infrared spectroscopy and nuclear magnetic resonance. Finally, as a proof of concept, the grafting of vanadium oxychloride (VOCl3) was successfully attempted.

  9. Atomic layer deposition TiO2 coated porous silicon surface: Structural characterization and morphological features

    International Nuclear Information System (INIS)

    Iatsunskyi, Igor; Jancelewicz, Mariusz; Nowaczyk, Grzegorz; Kempiński, Mateusz; Peplińska, Barbara; Jarek, Marcin; Załęski, Karol; Jurga, Stefan; Smyntyna, Valentyn

    2015-01-01

    TiO 2 thin films were grown on highly-doped p-Si (100) macro- and mesoporous structures by atomic layer deposition (ALD) using TiCl 4 and deionized water as precursors at 300 °C. The crystalline structure, chemical composition, and morphology of the deposited films and initial silicon nanostructures were investigated by scanning electron microscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy and X-ray diffraction (XRD). The mean size of TiO 2 crystallites was determined by TEM, XRD and Raman spectroscopy. It was shown that the mean crystallite size and the crystallinity of the TiO 2 are influenced dramatically by the morphology of the porous silicon, with the mesoporous silicon resulting in a much finer grain size and amorphous structure than the macroporous silicon having a partially crystal anatase phase. A simple model of the ALD layer growth inside the pores was presented. - Highlights: • The morphology and chemical composition of TiO 2 and porous Si were established. • The approximate size of TiO 2 nanocrystals was estimated. • The model of the atomic layer deposition coating in the porous Si was presented

  10. Three-dimensional morphological characterization of the skin surface micro-topography using a skin replica and changes with age.

    Science.gov (United States)

    Masuda, Y; Oguri, M; Morinaga, T; Hirao, T

    2014-08-01

    Skin surface micro-topography (SSMT), consisting of pores, ridges and furrows, reflects the skin condition and is an important factor determining the aesthetics of the skin. Most previous studies evaluating SSMT have employed two-dimensional image analysis of magnified pictures captured by a video microscope. To improve the accuracy of SSMT analysis, we established a three-dimensional (3D) analysis method for SSMT and developed various parameters including the skin ridge number, and applied the method to study the age-dependent change in skin. Confocal laser scanning microscopy was used for 3D measurement of the surface morphology of silicon replicas taken from the cheek. We then used these data to calculate the parameters that reflect the nature of SSTM including the skin ridge number using originally developed software. Employing a superscription technique, we investigated the variation in SSMT with age for replicas taken from the cheeks of 103 Japanese females (5-85 years old). The skin surface area and roughness, the area of pores, the area, length, depth and width of skin furrows and the number of skin ridges were examined. The surface roughness, the area of pores and the depth of skin furrows increased with age. The area and length of skin furrows and the number of skin ridges decreased with age. The method proposed to analyse SSMT three dimensionally is an effective tool with which to characterize the condition of the skin. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Synthesis, Characterization, Electrochemical and Surface Morphologies of Polyazomethines Containing Silane and Phosphazene Units.

    Science.gov (United States)

    Temizkan, Kevser; Kaya, İsmet

    2017-09-01

    Polyazomethines containing silane and phosphazene groups were synthesized via elimination reactions of dihydroxy compounds containing imine bonding with phosphazane and silane dichloride. The structures of monomers and polymers containing phosphazane and silane groups were supported by 1 H-NMR, 13 C-NMR, FT-IR and UV-Vis techniques. Electrochemical properties of the prepared Schiff bases and polymers were given by cyclic voltammetric (CV) analysis. Thermal properties of synthesized monomers and polymers were determined by TG-DTA and TG-DTA, DMA and DSC techniques, respectively. Molecular mass distributions of polymers are determined with gel permeation chromatography (GPC) measurement. Morphologic images of polymers containing heteroatom (silane/phosphazene) and azomethine linkage in the main chain were investigated by SEM techniques. The electrochemical band gap values of SB-1, SB-2, P-1, P-2 and P-3 compounds were found as 3.09, 3.30, 2.63, 3.07 and 3.04 eV, respectively.

  12. Morphology of ion-sputtered surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Makeev, Maxim A. E-mail: makeev@baton.phys.lsu.edu; Cuerno, Rodolfo; Barabasi, Albert-Laszlo

    2002-12-01

    We derive a stochastic nonlinear continuum equation to describe the morphological evolution of amorphous surfaces eroded by ion bombardment. Starting from Sigmund's theory of sputter erosion, we calculate the coefficients appearing in the continuum equation in terms of the physical parameters characterizing the sputtering process. We analyze the morphological features predicted by the continuum theory, comparing them with the experimentally reported morphologies. We show that for short time scales, where the effect of nonlinear terms is negligible, the continuum theory predicts ripple formation. We demonstrate that in addition to relaxation by thermal surface diffusion, the sputtering process can also contribute to the smoothing mechanisms shaping the surface morphology. We explicitly calculate an effective surface diffusion constant characterizing this smoothing effect and show that it is responsible for the low temperature ripple formation observed in various experiments. At long time scales the nonlinear terms dominate the evolution of the surface morphology. The nonlinear terms lead to the stabilization of the ripple wavelength and we show that, depending on the experimental parameters, such as angle of incidence and ion energy, different morphologies can be observed: asymptotically, sputter eroded surfaces could undergo kinetic roughening, or can display novel ordered structures with rotated ripples. Finally, we discuss in detail the existing experimental support for the proposed theory and uncover novel features of the surface morphology and evolution, that could be directly tested experimentally.

  13. Characterization of the corroded surface morphology of a carbon steel piping elbow affected by flow-accelerated corrosion

    International Nuclear Information System (INIS)

    Abe, Hiroshi; Watanabe, Yutaka; Nakashima, Makoto; Tatsuki, Tadashi

    2017-01-01

    It has been widely recognized that the inner surface of carbon steel piping affected by relatively severe flow-accelerated corrosion (FAC) shows typical morphology in terms of roughness in many cases. Although hydrodynamic parameters would determine the characteristics of the rough surface developed in such cases, the detailed mechanism of the roughness formation is not fully known. In this study, the local FAC rate profile and morphology in terms of surface roughness for an entire 90-degree carbon steel piping elbow used in a fossil power plant have been investigated under two-phase flow in order to discuss the relationships between the FAC rate and characteristics of the inner surface morphology. For the axial direction, the FAC rate gradually increased with distance from the inlet, and it reaches the peak value in the downstream side, beyond which, the value kept decreasing slightly. Distributed horse-shoe pits and scalloped patterns were observed on the extrados side. The finding suggests that the extrados side of the pipe wall was covered with a continuous liquid film (single-phase). The result shows the possibility of the occurrence of FAC by a single-phase flow in the area where there is a sudden change in flow regime, even when the nominal phase state of the fluid is a two-phase flow regime. Both the local FAC rate and scallop coverage increase steeply near the middle parts of the elbow. There was a good correlation between the two, but it was not a one-to-one relationship because a significant decrease in FAC rate was observed in the downstream side; in contrast, the entire surface was covered with a fine scalloped pattern. The change in the morphology in terms of surface roughness clearly indicated that the overlapping of horse-shoe shaped pits gave a scalloped appearance. The results revealed that the inner surface shape affected by FAC is considered to essentially depend on the number density of nucleation sites for pit formation. (author)

  14. Effect of Liquid Ga on Metal Surfaces: Characterization of Morphology and Chemical Composition of Metals Heated in Liquid Ga

    Directory of Open Access Journals (Sweden)

    Eun Je Lee

    2013-01-01

    Full Text Available This study investigates the effect of liquid gallium (Ga on metal foils made of titanium (Ti, niobium (Nb, and molybdenum (Mo. The Ti, Nb, and Mo foils were heated in liquid Ga at 120°C for a maximum of two weeks. After heating, the changes in the morphology and the chemical composition of the metal foils were analyzed by using a field emission scanning electron microscope, energy-dispersive X-ray spectrometer, X-ray diffractometer, and X-ray photoelectron spectrometer. The results of the analysis indicated that the Nb foil showed the minimum adhesion of liquid Ga to the surface while the maximum amount of liquid Ga was observed to adhere to the Ti foil. In addition, the Nb foil was oxidized and the Mo foil was reduced during the heating process. Considering these effects, we conclude that Mo may be used as an alternative encapsulation material for Ga in addition to Nb, which is used as the conventional encapsulation material, due to its chemical resistance against oxidation in hot liquid Ga.

  15. Stable phase CdS nanoparticles for optoelectronics: a study on surface morphology, structural and optical characterization

    Directory of Open Access Journals (Sweden)

    Kumar Suresh

    2016-06-01

    Full Text Available This work presents a study on the surface morphology, structure and optical behavior of stable phase cadmium sulphide (CdS nanoparticles synthesized via co-precipitation technique. Scanning electron microscopy (SEM analysis has been employed to study a cluster formation in the aggregated nanoparticles. An image analysis approach using ImageJ has been used to measure the size of nanoparticles from the SEM micrographs. Fourier transform infrared spectroscopic (FT-IR analysis identified absorption peaks of Cd–S stretching along with moisture content. X-ray diffraction (XRD analysis showed that CdS nanoparticles crystallized in wurtzite structure with a preferential orientation along (0 0 2 plane. The particle size, microstrain and lattice constants have been evaluated using XRD data. The lattice parameters of these nanoparticles were found to be shorter than the bulk value which led to lattice contraction. The optical absorption study showed a blue shift in the fundamental absorption edge indicating a quantum size effect.

  16. Growth morphologies of crystal surfaces

    Science.gov (United States)

    Xiao, Rong-Fu; Alexander, J. Iwan D.; Rosenberger, Franz

    1991-03-01

    We have expanded our earlier Monte Carlo model [Phys. Rev. A 38, 2447 (1988); J. Crystal Growth 100, 313 (1990)] to three dimensions and included reevaporation after accommodation and growth on dislocation-induced steps. We found again that, for a given set of growth parameters, the critical size, beyond which a crystal cannot retain its macroscopically faceted shape, scales linearly with the mean free path in the vapor. However, the three-dimensional (3D) the systems show increased shape stability compared to corresponding 2D cases. Extrapolation of the model results to mean-free-path conditions used in morphological stability experiments leads to order-of-magnitude agreement of the predicted critical size with experimental findings. The stability region for macroscopically smooth (faceted) surfaces in the parameter space of temperature and supersaturation depends on both the surface and bulk diffusion. While surface diffusion is seen to smooth the growth morphology on the scale of the surface diffusion length, bulk diffusion is always destabilizing. The atomic surface roughness increases with increase in growth temperature and supersaturation. That is, the tendency of surface kinetics anisotropies to stabilize the growth shape is reduced through thermal and kinetic roughening. It is also found that the solid-on-solid assumption, which can be advantageously used at low temperatures and supersaturations, is insufficient to describe the growth dynamics of atomically rough interfaces where bulk diffusion governs the process. For surfaces with an emerging screw dislocation, we find that the spiral growth mechanism dominates at low temperatures and supersaturations. The polygonization of a growth spiral decreases with increasing temperature or supersaturation. When the mean free path in the nutrient is comparable to the lattice constant, the combined effect of bulk and surface diffusion reduces the terrace width of a growth spiral in its center region. At elevated

  17. Characterization of solid surfaces

    National Research Council Canada - National Science Library

    Kane, Philip F; Larrabee, Graydon B

    1974-01-01

    .... A comprehensive review of surface analysis, this important volume surveys both principles and techniques of surface characterization, describes instrumentation, and suggests the course of future research...

  18. Atomic layer deposition TiO{sub 2} coated porous silicon surface: Structural characterization and morphological features

    Energy Technology Data Exchange (ETDEWEB)

    Iatsunskyi, Igor, E-mail: igoyat@amu.edu.pl [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska str., 61-614, Poznan (Poland); Department of Experimental Physics, Odessa National I.I. Mechnikov University, 42, Pastera str., 65023 Odessa (Ukraine); Jancelewicz, Mariusz; Nowaczyk, Grzegorz [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska str., 61-614, Poznan (Poland); Kempiński, Mateusz [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska str., 61-614, Poznan (Poland); Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poland (Poland); Peplińska, Barbara [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska str., 61-614, Poznan (Poland); Department of Macromolecular Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland); Jarek, Marcin; Załęski, Karol [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska str., 61-614, Poznan (Poland); Jurga, Stefan [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska str., 61-614, Poznan (Poland); Department of Macromolecular Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland); Smyntyna, Valentyn [Department of Experimental Physics, Odessa National I.I. Mechnikov University, 42, Pastera str., 65023 Odessa (Ukraine)

    2015-08-31

    TiO{sub 2} thin films were grown on highly-doped p-Si (100) macro- and mesoporous structures by atomic layer deposition (ALD) using TiCl{sub 4} and deionized water as precursors at 300 °C. The crystalline structure, chemical composition, and morphology of the deposited films and initial silicon nanostructures were investigated by scanning electron microscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy and X-ray diffraction (XRD). The mean size of TiO{sub 2} crystallites was determined by TEM, XRD and Raman spectroscopy. It was shown that the mean crystallite size and the crystallinity of the TiO{sub 2} are influenced dramatically by the morphology of the porous silicon, with the mesoporous silicon resulting in a much finer grain size and amorphous structure than the macroporous silicon having a partially crystal anatase phase. A simple model of the ALD layer growth inside the pores was presented. - Highlights: • The morphology and chemical composition of TiO{sub 2} and porous Si were established. • The approximate size of TiO{sub 2} nanocrystals was estimated. • The model of the atomic layer deposition coating in the porous Si was presented.

  19. Morphological characterization and evaluation of heat tolerance ...

    African Journals Online (AJOL)

    Morphological characterization and evaluation of heat tolerance traits in Nigerian goat breeds. M Wheto, BM Ilori, AJ Sanda, MA Adeleke, SO Durosaro, AS Adenaike, AO Adebambo, CON Ikeobi, OM Onagbesan, MO Ozoje, OA Adebambo ...

  20. Using shallow seismic tomography to characterize patterns of near-surface weathering and the mobile-immobile regolith transition: Implications for the erodibility and morphology of hillslopes.

    Science.gov (United States)

    Clarke, B. A.; Kirby, E.; Burbank, D. W.; West, N.

    2014-12-01

    We use 2D tomography of P- and S-wave velocities (Vp, Vs), based on seismic refraction and surface wave analyses, to characterize subsurface architecture and erodibility of hillslopes. Calibrating the seismic imagery with direct field observations allows us to quantify mechanical properties, image depth-dependent variations in weathering intensity, and identify the mobile-immobile regolith transition and differences in transport efficiency of mobile layers. We conducted a cross-CZO comparison of N- and S-facing slopes at Boulder Creek and Shale Hills CZOs (BcCZO and SSHCZO) to investigate how near-surface weathering and hillslope morphology are influenced by differences in regional geology and climatic as well as local variations in aspect-controlled microclimate. Niwot Ridge (BcCZO) is a high alpine site with minimal soil/veg cover, characterized by steeper S-facing hillslopes; whereas, SSHCZO is a temperate, densely-forested, soil-mantled site with steeper N-facing slopes. On Niwot Ridge, the depth of the weathering front and thickness of mobile regolith are substantially greater on shallower N-facing slopes; however, velocity-based estimates of transport efficiency are higher on S-facing slopes. Although, thin mobile regolith on S-facing slopes may be weaker (slower V), the lower gradient of N-facing slopes and southward asymmetry of the ridge divide, suggests greater transport efficiency on N-facing aspects. This can be explained by the dominance of frost/freeze process on N-facing slopes, which can efficiently develop and transport the thick mobile regolith. At SSHCZO, depths of weathering fronts are invariant with slope aspect, suggesting that aspect control is not a predominant mechanism driving regolith production. Mobile regolith thickness, however, is more than 2-fold greater on N-facing slopes. Additionally, mobile regolith on both slope aspects is primarily composed of well-developed soils. N-facing soils are thicker with greater cohesion, moisture, and

  1. Characterizing the Spatio-Temporal Pattern of Land Surface Temperature through Time Series Clustering: Based on the Latent Pattern and Morphology

    Directory of Open Access Journals (Sweden)

    Huimin Liu

    2018-04-01

    Full Text Available Land Surface Temperature (LST is a critical component to understand the impact of urbanization on the urban thermal environment. Previous studies were inclined to apply only one snapshot to analyze the pattern and dynamics of LST without considering the non-stationarity in the temporal domain, or focus on the diurnal, seasonal, and annual pattern analysis of LST which has limited support for the understanding of how LST varies with the advancing of urbanization. This paper presents a workflow to extract the spatio-temporal pattern of LST through time series clustering by focusing on the LST of Wuhan, China, from 2002 to 2017 with a 3-year time interval with 8-day MODerate-resolution Imaging Spectroradiometer (MODIS satellite image products. The Latent pattern of LST (LLST generated by non-parametric Multi-Task Gaussian Process Modeling (MTGP and the Multi-Scale Shape Index (MSSI which characterizes the morphology of LLST are coupled for pattern recognition. Specifically, spatio-temporal patterns are discovered after the extraction of spatial patterns conducted by the incorporation of k -means and the Back-Propagation neural networks (BP-Net. The spatial patterns of the 6 years form a basic understanding about the corresponding temporal variances. For spatio-temporal pattern recognition, LLSTs and MSSIs of the 6 years are regarded as geo-referenced time series. Multiple algorithms including traditional k -means with Euclidean Distance (ED, shape-based k -means with the constrained Dynamic Time Warping ( c DTW distance measure, and the Dynamic Time Warping Barycenter Averaging (DBA centroid computation method ( k - c DBA and k -shape are applied. Ten external indexes are employed to evaluate the performance of the three algorithms and reveal k - c DBA as the optimal time series clustering algorithm for our study. The study area is divided into 17 geographical time series clusters which respectively illustrate heterogeneous temporal dynamics of LST

  2. Surface characterization based upon significant topographic features

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, J; Grime, D; Blateyron, F, E-mail: fblateyron@digitalsurf.fr [Digital Surf, 16 rue Lavoisier, F-25000 Besancon (France)

    2011-08-19

    Watershed segmentation and Wolf pruning, as defined in ISO 25178-2, allow the detection of significant features on surfaces and their characterization in terms of dimension, area, volume, curvature, shape or morphology. These new tools provide a robust way to specify functional surfaces.

  3. Surface characterization based upon significant topographic features

    International Nuclear Information System (INIS)

    Blanc, J; Grime, D; Blateyron, F

    2011-01-01

    Watershed segmentation and Wolf pruning, as defined in ISO 25178-2, allow the detection of significant features on surfaces and their characterization in terms of dimension, area, volume, curvature, shape or morphology. These new tools provide a robust way to specify functional surfaces.

  4. Surface morphology and corrosion resistance of electrodeposited ...

    Indian Academy of Sciences (India)

    Administrator

    Surface morphology and corrosion resistance of electrodeposited composite coatings containing polyethylene or polythiophene in. Ni–Mo base. J NIEDBAŁA. Institute of Materials Science, University of Silesia, 40-007 Katowice, ul. Bankowa 12, Poland. MS received 11 December 2009; revised 30 April 2010. Abstract.

  5. Surface Evolution of Nano-Textured 4H–SiC Homoepitaxial Layers after High Temperature Treatments: Morphology Characterization and Graphene Growth

    Directory of Open Access Journals (Sweden)

    Xingfang Liu

    2015-09-01

    Full Text Available Nano-textured 4H–SiC homoepitaxial layers (NSiCLs were grown on 4H–SiC(0001 substrates using a low pressure chemical vapor deposition technique (LPCVD, and subsequently were subjected to high temperature treatments (HTTs for investigation of their surface morphology evolution and graphene growth. It was found that continuously distributed nano-scale patterns formed on NSiCLs which were about submicrons in-plane and about 100 nanometers out-of-plane in size. After HTTs under vacuum, pattern sizes reduced, and the sizes of the remains were inversely proportional to the treatment time. Referring to Raman spectra, the establishment of multi-layer graphene (MLG on NSiCL surfaces was observed. MLG with sp2 disorders was obtained from NSiCLs after a high temperature treatment under vacuum at 1700 K for two hours, while MLG without sp2 disorders was obtained under Ar atmosphere at 1900 K.

  6. Surface Evolution of Nano-Textured 4H–SiC Homoepitaxial Layers after High Temperature Treatments: Morphology Characterization and Graphene Growth

    Science.gov (United States)

    Liu, Xingfang; Chen, Yu; Sun, Changzheng; Guan, Min; Zhang, Yang; Zhang, Feng; Sun, Guosheng; Zeng, Yiping

    2015-01-01

    Nano-textured 4H–SiC homoepitaxial layers (NSiCLs) were grown on 4H–SiC(0001) substrates using a low pressure chemical vapor deposition technique (LPCVD), and subsequently were subjected to high temperature treatments (HTTs) for investigation of their surface morphology evolution and graphene growth. It was found that continuously distributed nano-scale patterns formed on NSiCLs which were about submicrons in-plane and about 100 nanometers out-of-plane in size. After HTTs under vacuum, pattern sizes reduced, and the sizes of the remains were inversely proportional to the treatment time. Referring to Raman spectra, the establishment of multi-layer graphene (MLG) on NSiCL surfaces was observed. MLG with sp2 disorders was obtained from NSiCLs after a high temperature treatment under vacuum at 1700 K for two hours, while MLG without sp2 disorders was obtained under Ar atmosphere at 1900 K. PMID:28347079

  7. Characterization and morphological properties of glass fiber ...

    African Journals Online (AJOL)

    Characterization and morphological properties of glass fiber reinforced epoxy composites fabricated under varying degrees of hand lay-up techniques. ... Hence, these composites are projected to possess better dimensional stability adaptable for high performance structural applications. Keywords: composite, interfacial ...

  8. Cultural, morphological, pathogenic and molecular characterization ...

    African Journals Online (AJOL)

    Alternaria blotch (Alternaria mali) causes severe foliar damage to apple trees in Kashmir. Twenty one (21) isolates of A. mali were collected from different locations and characterized for cultural, morphological, pathogenic and molecular variations. A. mali colonies varied in their cultural behaviour ranging from velvety to ...

  9. Isolation and morphological characterization of antibiotic producing ...

    African Journals Online (AJOL)

    Purpose: To isolate and characterize antibiotic producing actinomycetes from soil samples in Belgaum, Karnataka, India. Methods: Crowded plate technique was used for the isolation of actinomycetes in media such as soybean – casein digest medium and actinomycetes isolation agar. The morphological and cultural ...

  10. Structural and morphological characterization of cellulose pulp

    CSIR Research Space (South Africa)

    Ocwelwang, A

    2015-09-01

    Full Text Available International Symposium on Wood, Fibre and Pulping Chemistry, BOKU University, Vienna, Austria, 09-11th September 2015 9-11 September 2015 Structural and morphological characterization of cellulose pulp Atsile Ocwelwang1,2,*Bruce Sithole1,2, Deresh...

  11. Multiscale analysis of surface morphologies by curvelet and contourlet transforms

    International Nuclear Information System (INIS)

    Li, Linfu; Zhang, Xiangchao; Zhang, Hao; He, Xiaoying; Xu, Min

    2015-01-01

    The surface topographies of precision components are critical to their functionalities. However, it is challenging to characterize the topographies of complex surfaces, especially for structured surfaces. The wavelet families are promising for the multiscale geometry analysis of nonstochastic surfaces. The second-generation curvelet transform provides a sparse representation and good multiscale decomposition for curve singularities. However, the contourlet expansion, composed of bases oriented along various directions in multiple scales with smaller redundancy rates, has a remarkable capability of representing borderlines. In this paper they are both adopted for the characterization of surface topographies. Different components can be extracted according to their scales and morphological characteristics; as a result, the corresponding manufacturing processes and functionalities can be analyzed specifically. Numerical experiments are given to demonstrate the capabilities of these methods in sparse representation and effective extraction of geometry features of different nonstochastic surfaces. (paper)

  12. Reactive solid surface morphology variation via ionic diffusion.

    Science.gov (United States)

    Sun, Zhenchao; Zhou, Qiang; Fan, Liang-Shih

    2012-08-14

    In gas-solid reactions, one of the most important factors that determine the overall reaction rate is the solid morphology, which can be characterized by a combination of smooth, convex and concave structures. Generally, the solid surface structure varies in the course of reactions, which is classically noted as being attributed to one or more of the following three mechanisms: mechanical interaction, molar volume change, and sintering. Here we show that if a gas-solid reaction involves the outward ionic diffusion of a solid-phase reactant then this outward ionic diffusion could eventually smooth the surface with an initial concave and/or convex structure. Specifically, the concave surface is filled via a larger outward diffusing surface pointing to the concave valley, whereas the height of the convex surface decreases via a lower outward diffusion flux in the vertical direction. A quantitative 2-D continuum diffusion model is established to analyze these two morphological variation processes, which shows consistent results with the experiments. This surface morphology variation by solid-phase ionic diffusion serves to provide a fourth mechanism that supplements the traditionally acknowledged solid morphology variation or, in general, porosity variation mechanisms in gas-solid reactions.

  13. Cell behavior on microparticles with different surface morphology

    Energy Technology Data Exchange (ETDEWEB)

    Huang Sha [Wound Healing and Cell Biology Laboratory, Institute of Basic Medical Sciences, General Hospital of PLA, Beijing 100853 (China); Fu Xiaobing, E-mail: fuxiaobing@vip.sina.co [Wound Healing and Cell Biology Laboratory, Institute of Basic Medical Sciences, General Hospital of PLA, Beijing 100853 (China); Burns Institute, The First Affiliated Hospital, General Hospital of PLA, Trauma Center of Postgraduate Medical College, Beijing 100037 (China)

    2010-03-18

    Microparticles can serve as substrates for cell amplification and deliver the cell aggregation to the site of the defect for tissue regeneration. To develop favorable microparticles for cell delivery application, we fabricated and evaluated three types of microparticles that differ in surface properties. The microparticles with varied surface morphology (smooth, pitted and multicavity) were created from chemically crosslinked gelatin particles that underwent various drying treatments. Three types of microparticles were characterized and assessed in terms of the cell behavior of human keratinocytes and fibroblasts seeded on them. The cells could attach, spread and proliferate on all types of microparticles but spread and populated more slowly on the microparticles with smooth surfaces than on those with pitted or multicavity surfaces. Microparticles with a multicavity surface demonstrated the highest cell attachment and growth rate. Furthermore, cells tested on microparticles with a multicavity surface exhibited better morphology and induced the earlier formation of extracellular-based cell-microparticle aggregation than those on microparticles with other surface morphology (smooth and pitted). Thus, microparticles with a multicavity surface show promise for attachment and proliferation of cells in tissue engineering.

  14. Effect of surface morphology on the sputtering yields. II. Ion sputtering from rippled surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Makeev, Maxim A. E-mail: makeev@usc.edu; Barabasi, Albert-Laszlo E-mail: alb@nd.edu

    2004-08-01

    Off-normal ion bombardment of solid targets with energetic particles often leads to development of periodically modulated structures on the surfaces of eroded materials. Ion-induced surface roughening, in its turn, causes sputtering yield changes. We report on a comprehensive theoretical study of the effect of rippled surface morphology on the sputtering yields. The yield is computed as a function of the parameters characterizing the surface morphology and the incident ion beam, using the Sigmund's theory of ion sputtering. We find that the surface morphology development may cause substantial variations in the sputter yields, depending on a complex interplay between the parameters characterizing the ripple structure and the incident ion beam. For certain realizations of the ripple structure, the surface morphology is found to induce enhanced, relative to the flat surface value, sputtering yields. On the other hand, there exist regimes in which the sputtering yield is suppressed by the surface roughness below the flat surface result. We confront the obtained theoretical results with available experimental data and find that our model provides an excellent qualitative and, in some cases, quantitative agreement with the results of experimental studies.

  15. Microstructural characterization of hydrophobic Ti{sub 1-x}Al{sub x}N coatings with moth-eye-like surface morphology

    Energy Technology Data Exchange (ETDEWEB)

    Godinho, V., E-mail: godinho@icmse.csic.es [Instituto de Ciencia de Materiales de Sevilla CSIC-Uni. Sevilla, Av. Americo Vespucio 49, 41092 Sevilla (Spain); Lopez-Santos, C. [NAmur Research Institute for LIfe Sciences (NARILIS), Research Center in Physics of Matter and Radiation (PMR), University of Namur -FUNDP, 61 Rue de Bruxelles, 5000 Namur (Belgium); Rojas, T.C.; Philippon, D.; Jimenez de Haro, M.C. [Instituto de Ciencia de Materiales de Sevilla CSIC-Uni. Sevilla, Av. Americo Vespucio 49, 41092 Sevilla (Spain); Lucas, S. [NAmur Research Institute for LIfe Sciences (NARILIS), Research Center in Physics of Matter and Radiation (PMR), University of Namur - FUNDP, 61 Rue de Bruxelles, 5000 Namur (Belgium); Fernandez, A. [Instituto de Ciencia de Materiales de Sevilla CSIC-Uni. Sevilla, Av. Americo Vespucio 49, 41092 Sevilla (Spain)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Moth-eye-like structures were obtained by changing the power supplied to the targets at a constant N{sub 2} pressure. Black-Right-Pointing-Pointer The antireflecting properties and hydrophobicity of the coatings are discussed. Black-Right-Pointing-Pointer HREM and related techniques revealed the formation of meso- and nano-columns and different degree of open porosity. - Abstract: Ti{sub 1-x}Al{sub x}N thin films with different Al content were deposited by magnetron sputtering. The combination of electron energy loss spectroscopy (EELS) and energy dispersive spectroscopy (EDS) was used to evaluate the composition of the coatings. The effect of Al content on the morphology and properties of the coatings was investigated. High resolution electron microscopy and related techniques revealed the formation of a pillared moth-eye-like nanostructure with variable size and distribution of meso- and nano-columns and different degree of open porosity that depends on the Al content on the coating. For low Al content (x {<=} 0.21) c-(Ti,Al)N highly porous columns ending in a sharp pyramidal shape present low reflectivity and high hydrophobicity. While the precipitation of h-AlN phase at the column boundaries for x = 0.71 suppresses the c-(Ti,Al)N columnar growth and produces a smother surface, with higher reflectivity and less hydrophobic character.

  16. Structural and morphological characterization of CdSe:Mn thin films

    Indian Academy of Sciences (India)

    Sarika Singh

    2017-06-24

    Jun 24, 2017 ... C. The annealed samples were subjected to morphological and structural characterization using scanning electron microscope and XRD. XRD was used for structural characterization whereas scanning electron microscope shows the surface morphology of the films. XRD spectra reveal that the grown ...

  17. Wetting morphologies on chemically nanopatterned surfaces

    Science.gov (United States)

    Checco, Antonio; Gang, Oleg; Ocko, Benjamin M.

    2007-03-01

    We study the wetting of simple, volatile liquids on model chemical nanopatterns created using Local Oxidation Nanolithography. This technique makes use of a biased, metallic AFM tip to locally oxidize the methyl-terminations of a self-assembled monolayer (octadecylthrichlorosilane) into carboxylic acid termination[1]. With this method we have realized parallel, 50 to 500 nm wide, wettable stripes (carboxylic) embedded into a non-wettable (methyl) surface. Several organic (polar, non-polar), volatile liquids have been condensed onto the wettable stripes and the resulting droplet morphologies have been studied in-situ by using an environmental AFM. We show that close to saturation and for droplet thickness less than 10 nm long-range forces are relevant to the nanoliquid shape. These results are well described by Density Functional Theory assuming dispersive molecular interactions. In addition, we explore the dynamics of condensation/evaporation of the liquid nanodrops.

  18. The surface of Mars: Morphology and process

    Science.gov (United States)

    Aharonson, Oded

    The goal of this work is a quantitative description of the morphology of the surface of Mars, in order to constrain the nature of processes acting during the ancient past through today. Emphasis is placed on linking geometric properties to physical mechanisms. Surface smoothness on Mars is distinctive in the vast northern hemisphere plains. Amazonis Planitia is remarkable in its smoothness, exhibiting an rms variation in topography of building tectonics and volcanics. The shallower long-wavelength portion of the lowlands' topographic power spectrum relative to the highlands' can be accounted for by a simple model of sedimentation such as might be expected at an ocean's floor, but the addition of another process such as cratering is necessary to explain the spectral slope in short wavelengths. Large drainage systems on Mars have geomorphic characteristics that are inconsistent with prolonged erosion by surface runoff. We find the topography has not evolved to an expected equilibrium terrain form, even in areas where runoff incision has been previously interpreted. We demonstrate that features known as slope streaks form exclusively in regions of low thermal inertia, steep slopes, and incredibly, only where daily peak temperatures exceed 275 K during the martian year. The results suggest that at least small amounts of water may be currently present and undergo phase transitions. We detect subtle changes of the polar surface height during the course of seasonal cycles. Using altimetric crossover residuals, we show that while zonally averaged data captures the global behavior of CO 2 exchange, there is a strong dependence of the pattern on longitude. Decomposition of the signal into harmonics in time shows the amplitudes are correlated with the polar cap deposits. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

  19. Robust surface roughness indices and morphological interpretation

    Science.gov (United States)

    Trevisani, Sebastiano; Rocca, Michele

    2016-04-01

    Geostatistical-based image/surface texture indices based on variogram (Atkison and Lewis, 2000; Herzfeld and Higginson, 1996; Trevisani et al., 2012) and on its robust variant MAD (median absolute differences, Trevisani and Rocca, 2015) offer powerful tools for the analysis and interpretation of surface morphology (potentially not limited to solid earth). In particular, the proposed robust index (Trevisani and Rocca, 2015) with its implementation based on local kernels permits the derivation of a wide set of robust and customizable geomorphometric indices capable to outline specific aspects of surface texture. The stability of MAD in presence of signal noise and abrupt changes in spatial variability is well suited for the analysis of high-resolution digital terrain models. Moreover, the implementation of MAD by means of a pixel-centered perspective based on local kernels, with some analogies to the local binary pattern approach (Lucieer and Stein, 2005; Ojala et al., 2002), permits to create custom roughness indices capable to outline different aspects of surface roughness (Grohmann et al., 2011; Smith, 2015). In the proposed poster, some potentialities of the new indices in the context of geomorphometry and landscape analysis will be presented. At same time, challenges and future developments related to the proposed indices will be outlined. Atkinson, P.M., Lewis, P., 2000. Geostatistical classification for remote sensing: an introduction. Computers & Geosciences 26, 361-371. Grohmann, C.H., Smith, M.J., Riccomini, C., 2011. Multiscale Analysis of Topographic Surface Roughness in the Midland Valley, Scotland. IEEE Transactions on Geoscience and Remote Sensing 49, 1220-1213. Herzfeld, U.C., Higginson, C.A., 1996. Automated geostatistical seafloor classification - Principles, parameters, feature vectors, and discrimination criteria. Computers and Geosciences, 22 (1), pp. 35-52. Lucieer, A., Stein, A., 2005. Texture-based landform segmentation of LiDAR imagery

  20. Controlling morphology in swelling-induced wrinkled surfaces

    Science.gov (United States)

    Breid, Derek Ronald

    Wrinkles represent a pathway towards the spontaneous generation of ordered surface microstructure for applications in numerous fields. Examples of highly complex ordered wrinkle structures abound in Nature, but the ability to harness this potential for advanced material applications remains limited. This work focuses on understanding the relationship between the patterns on a wrinkled surface and the experimental conditions under which they form. Because wrinkles form in response to applied stresses, particular attention is given to the nature of the stresses in a wrinkling surface. The fundamental insight gained was then utilized to account for observed wrinkle formation phenomena within more complex geometric and kinetic settings. In order to carefully control and measure the applied stresses on a wrinkling film, a swelling-based system was developed using poly(dimethylsiloxane) (PDMS), surface-oxidized with a UV-ozone treatment. The swelling of the oxidized surface upon exposure to an ethanol vapor atmosphere was characterized using beam-bending experiments, allowing quantitative measurements of the applied stress. The wrinkle morphologies were characterized as a function of the overstress, defined as the ratio of the applied swelling stress to the critical buckling stress of the material. A transition in the dominant morphology of the wrinkled surfaces from dimple patterns to ridge patterns was observed at an overstress value of ˜2. The pattern dependence of wrinkles on the ratio of the principal stresses was examined by fabricating samples with a gradient prestress. When swollen, these samples exhibited a smooth morphological transition from non-equibiaxial to equibiaxial patterns, with prestrains as low as 2.5% exhibiting non-equibiaxial characteristics. This transition was seen both in samples with low and high overstresses. To explore the impact of these stress states in more complex geometries, wrinkling hemispherical surfaces with radii of curvature

  1. Morphological Characterization of Nanofibers: Methods and Application in Practice

    Directory of Open Access Journals (Sweden)

    Jakub Širc

    2012-01-01

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

  2. Effect of surface morphology on the sputtering yields. I. Ion sputtering from self-affine surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Makeev, Maxim A. E-mail: makeev@usc.edu; Barabasi, Albert-Laszlo E-mail: alb@nd.edu

    2004-08-01

    As extensive experimental studies have shown, under certain conditions, ion bombardment of solid targets induces a random (self-affine) morphology on the ion-eroded surfaces. The rough morphology development is known to cause substantial variations in the sputtering yields. In this article, we present a theoretical model describing the sputter yields from random, self-affine surfaces subject to energetic ion bombardment. We employ the Sigmund's theory of ion sputtering, modified for the case of self-affine surfaces, to compute the sputter yields. We find that the changes in the sputtering yield, associated with the non-planar surface morphology, are strongly dependent on the parameters characterizing the surface roughness (such as the saturation width and the correlation length) and the incident ion beam (such as the incident ion energy and the deposited energy widths). It is shown that, for certain ranges of the parameters variations, surface roughness leads to substantial enhancements in the yield, with magnitude of the effect being more than 100%, as compared to the flat surface value. Furthermore, we find that, depending on the interplay between these parameters, the surface roughness can both enhance and suppress the sputter yields.

  3. Morphological characterization ofMadura Cattle

    Directory of Open Access Journals (Sweden)

    Bambang Setiadi

    1998-12-01

    Full Text Available Morphological characterization of Madura cattle in Madura islands was done as an input for "action plans" of national animals genetic resources management according to the global system ofFAO. Assessments were done in Sumenep District and Pamekasan District, East Java. According to the body measurements, Madura cattle can be classified as a small to medium type with withers height of about 120 cm. Because of potential productivity in the limitation of environmental resources, Madura cattle can be classified as a "superior" cattle . Body measurements of Madura cattle in the present study were relatively the same with those of 50 years ago, indicating that there is no breeding improvement activities except natural selection . The variability of body measurements is relatively narrow . Improving productivity by outbreeding is needed . To conserve the unique germ plasm of the Indonesian genotype, such as Madura cattle and a possibility to improve their productivity by a complete prevention of cross breeding in the Madura islands needs further evaluation .

  4. Surface morphology of some articulated corallines from India

    Digital Repository Service at National Institute of Oceanography (India)

    Kerkar, V.; Iyer, S.D.

    Surface structures of seven species belonging to four genera of subfamily Corallinoidae (Fly: Corallinaceae) were microscopically investigated Two distinct surface morphologies were revealed namely a 'Corallina type' (c-type) with round to irregular...

  5. Variation in buccal surface morphology of deciduous first molars.

    Science.gov (United States)

    Simratvir, M; Moghe, G; Singh, D; Dhillon, K

    2012-01-01

    The buccal bulge of the deciduous first molars has always been a restorative challenge to the pediatric dentist. Morphologically it may vary from a slight prominence to a well-developed cusp-like structure. This study was conducted to determine the variable buccal surface morphology of deciduous first molar and its clinical relevance. A prospective study was conducted whereby 2016 patients visiting the outpatient clinic of dental hospital over 1 year were evaluated. Any variation in buccal surface morphology of the deciduous first molars was recorded photographically or by replicating in dental stone. Varied morphological patterns on buccal surface were observed for which a new classification scheme has been proposed. The surface morphology of deciduous teeth crowns must be studied carefully as it may be indicative of pulpal extensions and accessory roots, requiring consideration during restorative treatment planning.

  6. Cellulose whiskers: preparation, characterization and surface modification

    International Nuclear Information System (INIS)

    Taipina, Marcia O.; Ferrarezi, Marcia M.F.; Goncalves, Maria C.

    2011-01-01

    The main objectives of this work were to produce cellulose whiskers (from cotton fibers) by acid hydrolysis and subsequently modify the surface of these whiskers with 3-iso-cyanate-propyltrietoxy-silane. Cellulose whiskers structures were characterized by X-ray diffraction and Fourier transform infrared and their morphologies were investigated by scanning and transmission electron microscopy. Due to the hydrophilic nature of native cellulose, the formation of cellulose whisker nanocomposites is limited to water-soluble polymers. The applied methodology for surface modification of the whiskers allowed to obtain nanofibers with surface features more appropriate to allow the adhesion at fiber-matrix interface, which may result in a better performance of these fibers as reinforcing agents of hydrophobic polymer matrices. (author)

  7. Cultural, morphological, pathogenic and molecular characterization ...

    African Journals Online (AJOL)

    Dr tariq

    individual within a species, which are not fixed. This holds true with fungi also, although it is not frequent in asexually produced individuals of the progeny. Variability studies are important to document the changes occurring in populations and individuals as variability in morphological and physiological traits indicate the.

  8. Morphological and molecular characterization of Oyster mushroom ...

    African Journals Online (AJOL)

    Mushrooms have medicinal as well as nutritive value and extensively used as human food from the time immortal. In order to determine the genetic diversity among Pleurotus species of mushroom using morphological and random amplified polymorphic DNA (RAPD) markers, about seven different species were collected.

  9. Synthesis, structural and surface morphological characterizations of ...

    African Journals Online (AJOL)

    The nanoparticles have wide energy bandgap that varied from 3.80 to 4.00±0.05 eV and is therefore good candidate for solar cell and solar thermal applications. It also presents an attractive alternative material for biomedical implants due to its biocompatibility and mechanical strength. Keywords: Sulfated zirconia, sol-gel, ...

  10. Morphological and agronomic characterization of some tomato ...

    African Journals Online (AJOL)

    In a study of morphological and agronomic characteristics of eight tomato accessions, a high variability was detected in plant height at flowering, fruit set, number of fruits per plant, fruit weight, number of locules per fruit, and yield. The variation in percent total soluble solids (3.9-5.0) and pH (3.9-4.4) was very small. The pH ...

  11. Morphological and molecular characterization of Amblyomma ...

    African Journals Online (AJOL)

    The association of most tick-borne pathogens with specific tick species has made it imperative that proper identification and characterization of such tick vectors is necessary for the purpose of developing effective tick and tick-borne control strategies. This study was undertaken to identify and characterize Amblyomma ...

  12. Oxygen reduction reaction over silver particles with various morphologies and surface chemical states

    Science.gov (United States)

    Ohyama, Junya; Okata, Yui; Watabe, Noriyuki; Katagiri, Makoto; Nakamura, Ayaka; Arikawa, Hidekazu; Shimizu, Ken-ichi; Takeguchi, Tatsuya; Ueda, Wataru; Satsuma, Atsushi

    2014-01-01

    The oxygen reduction reaction (ORR) in an alkaline solution was carried out using Ag powders having various particle morphologies and surface chemical states (Size: ca. 40-110 nm in crystalline size. Shape: spherical, worm like, and angular. Surface: smooth with easily reduced AgOx, defective with AgOx, and Ag2CO3 surface layer). The various Ag powders were well characterized by X-ray diffraction, X-ray photoelectron spectroscopy, N2 adsorption, scanning electron microscopy, Raman spectroscopy, cyclic voltammetry, and stripping voltammetry of underpotential-deposited lead. Defective and oxidized surfaces enhanced the Ag active surface area during the ORR. The ORR activity was affected by the morphology and surface chemical state: Ag particles with defective and angular surfaces showed smaller electron exchange number between three and four but showed higher specific activity compared to Ag particles with smooth surfaces.

  13. Micromechanical Characterization of Complex Polypropylene Morphologies by HarmoniX AFM

    Directory of Open Access Journals (Sweden)

    S. Liparoti

    2017-01-01

    Full Text Available This paper examines the capability of the HarmoniX Atomic Force Microscopy (AFM technique to draw accurate and reliable micromechanical characterization of complex polymer morphologies generally found in conventional thermoplastic polymers. To that purpose, injection molded polypropylene samples, containing representative morphologies, have been characterized by HarmoniX AFM. Mapping and distributions of mechanical properties of the samples surface are determined and analyzed. Effects of sample preparation and test conditions are also analyzed. Finally, the AFM determination of surface elastic moduli has been compared with that obtained by indentation tests, finding good agreement among the results.

  14. IDENTIFYING THE LOCAL SURFACE URBAN HEAT ISLAND THROUGH THE MORPHOLOGY OF THE LAND SURFACE TEMPERATURE

    Directory of Open Access Journals (Sweden)

    J. Wang

    2016-06-01

    Full Text Available Current characterization of the Land Surface Temperature (LST at city scale insufficiently supports efficient mitigations and adaptations of the Surface Urban Heat Island (SUHI at local scale. This research intends to delineate the LST variation at local scale where mitigations and adaptations are more feasible. At the local scale, the research helps to identify the local SUHI (LSUHI at different levels. The concept complies with the planning and design conventions that urban problems are treated with respect to hierarchies or priorities. Technically, the MODerate-resolution Imaging Spectroradiometer satellite image products are used. The continuous and smooth latent LST is first recovered from the raw images. The Multi-Scale Shape Index (MSSI is then applied to the latent LST to extract morphological indicators. The local scale variation of the LST is quantified by the indicators such that the LSUHI can be identified morphologically. The results are promising. It can potentially be extended to investigate the temporal dynamics of the LST and LSUHI. This research serves to the application of remote sensing, pattern analysis, urban microclimate study, and urban planning at least at 2 levels: (1 it extends the understanding of the SUHI to the local scale, and (2 the characterization at local scale facilitates problem identification and support mitigations and adaptations more efficiently.

  15. Investigations of the Band Structure and Morphology of Nanostructured Surfaces

    Science.gov (United States)

    Knox, Kevin R.

    2011-12-01

    In this dissertation, I examine the electronic structure of two very different types of two-dimensional systems: valence band electrons in single layer graphene and electronic states created at the vacuum interface of single crystal copper surfaces. The characteristics of both electronic systems depend intimately on the morphology of the surfaces they inhabit. Thus, in addition to discussing the respective band structures of these systems, a significant portion of this dissertation will be devoted to measurements of the surface morphology of these systems. Free-standing exfoliated monolayer graphene is an ultra-thin flexible membrane and, as such, is known to exhibit large out-of-plane deformation due to substrate and adsorbate interaction as well as thermal vibrations and, possibly, intrinsic buckling. Such crystal deformation is known to limit mobility and increase local chemical reactivity. Additionally, deformations present a measurement challenge to researchers wishing to determine the band structure by angle-resolved photoemission since they limit electron coherence in such measurements. In this dissertation, I present low energy electron microscopy and micro probe diffraction measurements, which are used to image and characterize corrugation in SiO2-supported and suspended exfoliated graphene at nanometer length scales. Diffraction line-shape analysis reveals quantitative differences in surface roughness on length scales below 20 nm which depend on film thickness and interaction with the substrate. Corrugation decreases with increasing film thickness, reflecting the increased stiffness of multilayer films. Specifically, single-layer graphene shows a markedly larger short range roughness than multilayer graphene. Due to the absence of interactions with the substrate, suspended graphene displays a smoother morphology and texture than supported graphene. A specific feature of suspended single-layer films is the dependence of corrugation on both adsorbate load

  16. Mineralogical and particulate morphological characterization of ...

    African Journals Online (AJOL)

    Six representative geophagic clayey soils from Botswana were mineralogically characterized using X-ray powder diffractometry (XRPD), optical microscopy, and environmental scanning electron microscopy (ESEM). Results of identified mineral phases revealed quartz (SiO2) as the most dominant in all samples constituting ...

  17. Morphological characterization and identification of Phytophthora ...

    African Journals Online (AJOL)

    Frequent outbreaks of citrus gummosis in Kenyan citrus orchards have been reported, yet the identity and distribution of the Phytophthora species causing the disease are unknown. Work was carried out to (i) characterize and identify Phytophthora species associated with citrus gummosis based on cultural and ...

  18. morphological characterization and of phytophthora species causing ...

    African Journals Online (AJOL)

    Toshiba A205

    2012-12-07

    Dec 7, 2012 ... Virulence tests. Forty five isolates of P. citrophthora, thirteen isolates of P. nicotianae and one isolate of P. syringae were initially tested for virulence on lemon (var. rough lemon) fruits. Mature green fruits of uniform size were washed in running tap water and surface disinfected for 1 to 2 min in 75% ethanol.

  19. The surface of Io - Geologic units, morphology, and tectonics

    Science.gov (United States)

    Schaber, G. G.

    1980-09-01

    The geologic units, morphology and tectonics evident on a preliminary geological map obtained from best-resolution Voyager 1 images and a preliminary pictorial map of the surface of Io are discussed. Nine volcanic units are identified on the surface which are composed of mountain materials, intervent, layered and eroded layered plains, and wall and floor, pit crater flow, shield crater flow, fissure flow and crater cone units associated with volcanic vents, along with seven types of structural features. The cumulative volcanic crater size distribution of 170 Ionian vents with craters greater than 14 km is similar to that of impact craters on other solar system bodies, with a surplus of small craters and a preponderance of volcanic vents in the Io equatorial zone. The observed surface morphologies provide evidence for a mixture of silicates and sulfur as the dominant surface material. Lineaments and grabens are also apparent on the surface, in a common planetary grid pattern.

  20. Characterization of Morphology using MAMA Software

    Energy Technology Data Exchange (ETDEWEB)

    Gravelle, Julie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-02

    The MAMA (Morphological Analysis for Material Attribution) software was developed at the Los Alamos National Laboratory funded through the National Technical Nuclear Forensics Center in the Department of Homeland Security. The software allows images to be analysed and quantified. The largest project I worked on was to quantify images of plutonium oxides and ammonium diuranates prepared by the group with the software and provide analyses on the particles of each sample. Images were quantified through MAMA, with a color analysis, a lexicon description and powder x-ray diffraction. Through this we were able to visually see a difference between some of the syntheses. An additional project was to revise the manual for MAMA to help streamline training and provide useful tips to users to more quickly become acclimated to using the software. The third project investigated expanding the scope of MAMA and finding a statistically relevant baseline for the particulates through the analysis of maps in the software and using known measurements to compare the error associated with the software. During this internship, I worked on several different projects dealing with the MAMA software. The revision of the usermanual for the MAMA software was the first project I was able to work and collaborate on. I first learned how to use the software by getting instruction from a skilled user at the laboratory, Dan Schwartz, and by using the existing user manual and examples. After becoming accustomed to the program, I started to go over the manual to correct and change items that were not as useful or descriptive as they could have been. I also added in tips that I learned as I explored the software. The updated manual was also worked on by several others who have been developing the program. The goal of these revisions was to ensure the most concise and simple directions to the software were available to future users. By incorporating tricks and shortcuts that I discovered and picked up

  1. Morphological and structural characterization of fly ash powders

    OpenAIRE

    Gabriel Peña-Rodríguez; Luis René Ortega-Triana

    2014-01-01

    Morphological and structural characterization of fly ash powder's reports are obtained from coal  combustion supplied by the thermal - electrical plant Termotasajero S.A. The morphological study consisted in the superficial analysis, using Scanning electron microscopy (SEM). The basic chemical composition was found using X ray energy dispersion spectrums (EDX - SEM) whereas structural characterization was developed by X-ray diffraction (XRD). The software Image tool V. 3.0. was used for the p...

  2. Surface roughness and morphologic changes of zirconia: Effect of ...

    African Journals Online (AJOL)

    Purpose: The purpose of this study was to investigate the surface roughness and morphologic changes of pre.sintered ZrO2 after sandblasting and erbium, chromium: Yttrium, scandium, gallium, garnet (Er, Cr: YSGG) laser application of different intensities. Material and Methods: Eighty pre-sintered ZrO2 cylinders (7 mm ...

  3. Morphology of Myoepithelium and Basal Surface of the Glandular ...

    African Journals Online (AJOL)

    Broad Objective: To study the morphology of the myoepithelial cells and the basal surfaces of the glandular cells in the small and large lobes of the Harderian gland. Study Setting and Methodology: The study used the scanning electron and lesser confocal microscopes to observe the Harderian gland of the golden hamster.

  4. Influence of deposition rate on PL spectrum and surface morphology ...

    Indian Academy of Sciences (India)

    Influence of deposition rate on PL spectrum and surface morphology of ZnO nanolayers deposited on Si (100) substrate. A ZENDEHNAM. ∗. , M MIRZAEE and S MIRI. Thin Film Laboratory, Department of Physics, Faculty of Science, Arak University, Arak 38156-8-8349, Iran. MS received 26 March 2012; revised 5 May 2012.

  5. Surface morphology of amygdala is associated with trait anxiety.

    Directory of Open Access Journals (Sweden)

    Shuyu Li

    Full Text Available Previous neuroimaging studies have suggested a role of amygdala in trait anxiety level, in which amygdala was typically treated as a whole. To date, it remains unknown whether the morphology of specific subregions of amygdala are associated with trait anxiety. Here, we employed a shape analysis approach to locate the association between its morphology and trait anxiety on the surface of amygdala. 24 healthy young participants were included. The boundary of amygdala for each subject was first manually outlined using high-resolution magnetic resonance (MR image, followed by 3D surface reconstruction and parameterization using spherical harmonic description. Two point-wise metrics, direct displacement between the individual surface and atlas surface and its normal projection, were used to quantify the surface morphology of amygdala. Statistical analysis revealed significant correlations between the two surface metrics and trait anxiety levels, which were located around the lateral and central nucleus of right amygdala. Our results provided localized information for the association between amygdala and trait anxiety, and suggested a central role of the lateral and central nucleus of right amygdala on trait anxiety.

  6. Metropolitan landscape characterization: A typo-morphological approach

    OpenAIRE

    Tisma, A.; Van der Velde, J.R.T.; Nijhuis, S.; Pouderoyen, B.J.J.M.

    2012-01-01

    Dispersed urban regions are characterized by blurred boundaries between urban and rural areas resulting in complex new configurations of urban tissue and landscape space. These new hybrid landscapes challenge existing tools for landscape characterization, which are based on a traditional separation of urban and non-urban realms. This paper presents the results of the elaboration and testing of the method for character assessment using continuity and land-use for the study of the morphology of...

  7. Characterization and morphology of solids suspended in rain water

    International Nuclear Information System (INIS)

    Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la

    2000-01-01

    This work presents the results obtained from the analysis of rain water in Mexico. The study treats over the characterization and morphology of the solids suspended in form of particles in the atmosphere. The solids suspended were obtained of the pluvial precipitations after these have been centrifuged. Subsequently of the separation, the particulate matter was analysed by Sem and X-ray dispersive energy

  8. Morphological Characterization of the African Giant Rat ( Cricetomys ...

    African Journals Online (AJOL)

    This experiment was designed to investigate the morphological characterization of the brain cortices of African giant rats, AGR (Cricetomys gambianus, Waterhouse) across age groups as related to function. A total of 15 male AGR were used for this study comprising of 5 neonates, 5 juveniles and 5 adults. Brains were ...

  9. Morphological characterization of local pigs in Ghana | Adjei ...

    African Journals Online (AJOL)

    A greater number of the local pigs (70.55%) showed aggressive temperament. The data gathered from this study should contribute to the development of sustainable conservation schemes for local pig genetic resources and prevent their extinction. Keywords; characterization, morphological, ADP, conservation ...

  10. Tribological behaviors of UHMWPE composites with different counter surface morphologies

    Science.gov (United States)

    Wang, Yanzhen; Yin, Zhongwei; Li, Hulin; Gao, Gengyuan

    2017-12-01

    The influence of counter surface morphologies on hybrid glass fiber (GF) and carbon fiber (CF) filled ultrahigh molecular weight polyethylene (UHMWPE) were studied under various contact pressure and sliding speed against GCr15 steel in dry condition. The goals were to investigate the tribological behavior of GF/CF/UHMWPE composite as a kind of water lubricated journal bearing material. The friction and wear behavior of composites were examined using a pin-on-disc tribometer. The morphologies of the worn surface were examined by scanning electron microscopy (SEM) and laser 3D micro-imaging and profile measurement. Generally, the wear rate and friction coefficient of composites increase as the increment of counter surface roughness. The friction coefficient increases firstly and then decrease with an increase in sliding speed and contact pressure for counterface with Ra=0.2 and 3.5 μm, while the friction coefficient decreased for counterface with Ra=0.6 μm.

  11. AFM surface morphology investigation of ion beam modified polyimide

    Science.gov (United States)

    Švorčík, V.; Arenholz, E.; Rybka, V.; Hnatowicz, V.

    1997-03-01

    Polyimide Upilex R was irradiated with 90 keV N + ions to the fluences of 1 × 10 14-2 × 10 17 cm -2. The surface morphology and the structure of the ion beam modified PI were examined using atomic force microscopy and X-ray difraction. Sheet resistance as a function of the ion fluence and the sample temperature was measured by standard two point technique. Significant changes of the surface morphology and production of graphitic phase in the sample surface layer modified by the ion irradiation were observed. Strong decrease of the sheet resistance (by 11 orders of magnitude) in the ion beam modified samples is connected with progressive carbonization and graphitization of the degraded polymer. Electrical charge transport is mediated by variable-range hopping mechanism. Drastic structural changes initiated by the ion irradiation to high fluences are similar to those observed in polymer pyrolysis.

  12. Relationship between surface structure and morphology of Fe3O4/silica composite nanospheres and nucleic acid extraction

    International Nuclear Information System (INIS)

    Zeng Wen; Xu Hong; Yang Yongzhe; Gu Hongchen

    2009-01-01

    Fe 3 O 4 /silica composite nanospheres with different surface structure and morphology were synthesized by changing reaction conditions. As-synthesized nanospheres were characterized by high performance particle sizer (HPPS), transmission electron microscopy (TEM), nitrogen adsorption and thermogravimetry (TGA). Besides thoroughly characterization, the particles were used for DNA extraction. We found that the particle surface structure and morphology affected the nucleic acid extraction efficiency. When comparing different samples with the same silanol density (10 18 ), the one with a surface area of 60.37 m 2 /g extracted DNA most effectively. Also, with increasing silanol density per surface area, DNA extraction efficiency increased.

  13. Dynamic and reversible surface topography influences cell morphology.

    Science.gov (United States)

    Kiang, Jennifer D; Wen, Jessica H; del Álamo, Juan C; Engler, Adam J

    2013-08-01

    Microscale and nanoscale surface topography changes can influence cell functions, including morphology. Although in vitro responses to static topography are novel, cells in vivo constantly remodel topography. To better understand how cells respond to changes in topography over time, we developed a soft polyacrylamide hydrogel with magnetic nickel microwires randomly oriented in the surface of the material. Varying the magnetic field around the microwires reversibly induced their alignment with the direction of the field, causing the smooth hydrogel surface to develop small wrinkles; changes in surface roughness, ΔRRMS , ranged from 0.05 to 0.70 μm and could be oscillated without hydrogel creep. Vascular smooth muscle cell morphology was assessed when exposed to acute and dynamic topography changes. Area and shape changes occurred when an acute topographical change was imposed for substrates exceeding roughness of 0.2 μm, but longer-term oscillating topography did not produce significant changes in morphology irrespective of wire stiffness. These data imply that cells may be able to use topography changes to transmit signals as they respond immediately to changes in roughness. Copyright © 2013 Wiley Periodicals, Inc.

  14. The influence of fabric surface characteristics on satellite bloodstain morphology.

    Science.gov (United States)

    Miles, H F; Morgan, R M; Millington, J E

    2014-07-01

    Bloodstains on fabrics such as clothing, soft furnishings or carpets are often encountered in casework. These stains often have a distinctive morphology that includes satellite stains, thought to be a highly sensitive feature that is a function of surface roughness. This study presents the findings of experimental studies conducted with proxy blood on two fabrics, similar in labeled composition, to assess the influence of fabric type on satellite stain generation. The morphology of proxy blood stains on the two fabric types were found to be statistically distinguishable from one another, with the volume of satellite stains generated being dependent upon the surface roughness of the fabric. These findings provide an initial step that illustrates the viability of providing an empirical evidence base for the interpretation of satellite stains in forensic blood pattern analysis (BPA). Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  15. Effect of surface morphology on the fracture strength of silicon nanobeams

    Science.gov (United States)

    Alan, Tuncay; Hines, Melissa A.; Zehnder, Alan T.

    2006-08-01

    The effect of nanoscale surface morphology on the fracture strength of 190-nm-thick, doubly clamped Si beams was measured experimentally. The surface morphology was controlled through aqueous etching and characterized by atomic force microscopy. The beams fractured along the primary cleavage planes, {111}. Fracture strength was extracted using finite element simulations of the experiment. Nanobeams etched with relatively smooth morphologies (0.4nm rms) were able to sustain a tensile stress of 15.8GPa, close to theoretical strengths predicted by previous atomistic calculations. In contrast, nanobeams decorated with nanometer-high step bunches (1.5nm rms) had a 20% lower fracture strength, 12.8GPa, suggesting that careful attention to processing is necessary for maximum strength.

  16. MORPHOLOGICAL CHARACTERIZATION OF MALAYSIAN WILD BANANA MUSA ACUMINATA

    Directory of Open Access Journals (Sweden)

    MUHAMMAD ASIF JAVED

    2002-01-01

    Full Text Available Fourteen populations of Musa acuminata ranging from populations in the lowlands of northern (ssp. siamea to central Malaysian region (ssp. malaccensis and highland banana (ssp. truncata were characterized based on chromosome number and 46 morphological characters. A large amount of variation was observed within the populations. However, only highland bananas appeared morphologically distinct. Lowland populations both from northern and central Malaysia were found to be overlapping and no distinguishing pattern was observed. The morphological characters found variable within these populations were related to developmental changes and mutations. The results ob tained in this study were not revolutionary. However, the survey of a large number of characters treated with multivariate techniques further sharpened the existing groupings of the Musa acuminata subspecies.

  17. Soft electronic structure modulation of surface (thin-film) and bulk (ceramics) morphologies of TiO{sub 2}-host by Pb-implantation: XPS-and-DFT characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zatsepin, D.A. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620990 Yekaterinburg (Russian Federation); Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg (Russian Federation); Boukhvalov, D.W., E-mail: danil@hanyang.ac.kr [Department of Chemistry, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Theoretical Physics and Applied Mathematics Department, Ural Federal University, Mira Street 19, 620002 Yekaterinburg (Russian Federation); Gavrilov, N.V. [Institute of Electrophysics, Russian Academy of Sciences, Ural Branch, 620990 Yekaterinburg (Russian Federation); Zatsepin, A.F. [Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg (Russian Federation); Shur, V.Ya.; Esin, A.A. [Institute of Natural Sciences, Ural Federal University, 51 Lenin Ave, 620000 Yekaterinburg (Russian Federation); Kim, S.S. [School of Materials Science and Engineering, Inha University, Incheon 402-751 (Korea, Republic of); Kurmaev, E.Z. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620990 Yekaterinburg (Russian Federation); Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg (Russian Federation)

    2017-04-01

    Highlights: • Experiment and theory demonstrate significant difference between patterns of Pb-ion implantation in TiO{sub 2}. • In bulk TiO{sub 2} Pb-impurities leads formation of PbO phase. • On the surface of TiO{sub 2}:Pb occur formation of PbxOy configurations. • In both bulk and surface TiO{sub 2}:Pb occur decreasing of the bandgap by shift of valence band about 1 eV up. - Abstract: The results of combined experimental and theoretical study of substitutional and clustering effects in the structure of Pb-doped TiO{sub 2}-hosts (bulk ceramics and thin-film morphologies) are presented. Pb-doping of the bulk and thin-film titanium dioxide was made with the help of pulsed ion-implantation without posterior tempering (Electronic Structure Modulation Mode). The X-ray photoelectron spectroscopy (XPS) qualification of core-levels and valence bands and Density-Functional Theory (DFT) calculations were employed in order to study the yielded electronic structure of Pb-ion modulated TiO{sub 2} host-matrices. The combined XPS-and-DFT analysis has agreed definitely with the scenario of the implantation stimulated appearance of PbO-like structures in the bulk morphology of TiO{sub 2}:Pb, whereas in thin-film morphology the PbO{sub 2}-like structure becomes dominating, essentially contributing weak O/Pb bonding (Pb{sub x}O{sub y} defect clusters). The crucial role of the oxygen hollow-type vacancies for the process of Pb-impurity “insertion” into the structure of bulk TiO{sub 2} was pointed out employing DFT-based theoretical background. Both experiment and theory established clearly the final electronic structure re-arrangement of the bulk and thin-film morphologies of TiO{sub 2} because of the Pb-modulated deformation and shift of the initial Valence Base-Band Width about 1 eV up.

  18. Laser treatment of boron carbide surfaces: Metallurgical and morphological examinations

    Energy Technology Data Exchange (ETDEWEB)

    Yilbas, B.S., E-mail: bsilbas@kfupm.edu.sa; Karatas, C.

    2014-08-01

    Highlights: • Dense layer with fine grains is formed at surface. • Irregular shaped grains and dendrites are formed below dense layer. • Assisting gas forms nitride species (BN and BC{sub 2}N) at surface. • Fracture toughness of treated surface reduces because of high hardness. • Residual stress is compressive and the maximum residual stress is about 0.9 GPa. - Abstract: Laser treatment of B{sub 4}C tile surfaces is carried out under high pressure nitrogen assisting gas environment. Morphological and metallurgical changes in the laser treated layer are examined by incorporating scanning electron microscope, energy dispersive spectroscopy, and X-ray diffraction. Microhardness and fracture toughness of the laser treated surface are determined from the indentation data. Residual stress formed at the treated surface is obtained by using X-ray diffraction technique. It is found that laser treated surface is free from large scale asperities including cracks and voids; however, some locally scattered shallow cavities with 1.5–2 μm widths are formed at the surface because of high temperature processing. Dense layer, consisting of fine grains, and formation of nitride species (BN and BC{sub 2}N) enhance microhardness and lower fracture toughness at the surface. Residual stress formed in the treated layer is compressive and the maximum residual stress is in the order of −0.9 GPa.

  19. Biodiversity of Andean potatoes: Morphological, nutritional and functional characterization.

    Science.gov (United States)

    Calliope, Sonia Rosario; Lobo, Manuel Oscar; Sammán, Norma Cristina

    2018-01-01

    Andean potatoes (Solanum tuberosum andigenum) are a staple food for Andean population; there is great biodiversity but only few varieties are cultivated nowadays. In order to contribute to biodiversity conservation of Andean potatoes, information about their morphological, nutritional and functional characteristics was generated. In gene bank (INTA-Balcarce), varieties collected from regional producers were preserved. Forty-four genotypes were multiplied and characterized. Morphological characteristics; proximate composition and functional compounds were analyzed. Cluster analysis separated them into 3 groups according to distinguishing characteristics, which define industrial or nutritional applications. Group 2 was characterized by higher content of macronutrients and Group 3 with the highest antioxidant activity, both would be advisable for direct consumption. Genotype CS 1418 had big size and oval form so it could be destined to potato chips industry. Knowledge on nutritional and functional properties of genotypes contributes to promoting the cultivation depending on properties and also to preserve biodiversity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Effect of alkali treatment on surface morphology of titanium

    Energy Technology Data Exchange (ETDEWEB)

    Tan, K. J., E-mail: gd130056@siswa.uthm.edu.my; Wahab, M. A. A., E-mail: cd110006@siswa.uthm.edu.my; Mahmod, S., E-mail: cd110201@siswa.uthm.edu.my; Idris, M. I., E-mail: izwana@uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Alkali and heat treatments were first introduced by Kim et al. to prepare a bioactive surface on titanium. This method has been proven very effective and widely used in other studies to promote titanium osteointegration. This study aims to investigate further the effect of alkali treatment on surface morphology of high purity titanium. High purity titanium foils were immersed in NaOH aqueous solutions of 0.5 M, 5 M and 15 M at 60°C and 80 °C for 1, 3 and 7 days. The surface morphology was examined using Field Emission Scanning Electron Microscope (FESEM). The obtained phases were analysed using Fourier Transform Infrared Spectroscopy (FTIR) in the spectra range of 4000-600 cm{sup −1} at 4 cm{sup −1} resolution and 50 scans. At the same soaking temperature and soaking time, a thicker porous network was observed with increasing concentration of NaOH. At the same soaking temperature, a much porous structure was observed with increasing soaking time. At constant alkali concentration, more homogenously distributed porous surface structure was observed with increasing soaking temperature.

  1. Surface Morphology and Tooth Adhesion of a Novel Nanostructured Dental Restorative Composite

    Directory of Open Access Journals (Sweden)

    Marco Salerno

    2016-03-01

    Full Text Available Recently, a novel dental restorative composite based on nanostructured micro-fillers of anodic porous alumina has been proposed. While its bulk properties are promising thanks to decreased aging and drug delivery capabilities, its surface properties are still unknown. Here we investigated the surface morphology and the adhesion to tooth dentin of this composite as prepared. For comparison, we used two commercial composites: Tetric EVO Flow (Ivoclar and Enamel HRi Plus (Micerium. The surface morphology was characterized by atomic force microscopy and the adhesion strength by tensile tests. The experimental composite is rougher than the commercial composites, with root mean square roughness of ~549 nm against 170–511 nm, and presents an adhesion strength of ~15 MPa against 19–21 MPa. These results show at the same time some proximity to the commercial composites, but also the need for optimization of the experimental material formulation.

  2. 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.

  3. Structural and morphological characterization of CdSe:Mn thin films

    Science.gov (United States)

    Singh, Sarika; Shrivastava, A. K.

    2017-07-01

    CdSe:Mn thin films were grown by chemical bath deposition. The pH of the solution was maintained at 11. Dry films so obtained were annealed in vacuum (10^{-1} Torr) for about 2 h at 400°C. The annealed samples were subjected to morphological and structural characterization using scanning electron microscope and XRD. XRD was used for structural characterization whereas scanning electron microscope shows the surface morphology of the films. XRD spectra reveal that the grown CdSe films are polycrystalline in nature and have cubic structure. The average particle size decreases on doping CdSe with Mn ions. The FE-SEM images show spherical particles having uniform distribution. Optical characterization was done using PL studies and UV-Visible spectrophotometer. PL spectra show an increase in PL intensity on doping. Optical band gap also decreases on doping.

  4. The role of surface morphology in nanocatalyst engineering

    Energy Technology Data Exchange (ETDEWEB)

    Stamenkovic, V. [Argonne National Laboratory, Argonne, IL (United States). Material Science Div.

    2008-07-01

    This study investigated extended polycrystalline platinum (Pt) alloys and PtNi(hkl) and Pt(hkl) single crystalline surfaces for various catalytic reactions. The surfaces were treated in an ultra-high vacuum by sputtering and annealing cycles. Auger electron spectroscopy (AES), low energy ion spectroscopy (LEIS), and ultraviolet photoelectron spectroscopy (UPS) techniques were used to characterize the alloys before they were transferred into an electrochemical environment. The study showed that electronic effect was caused by changes in the metallic d-band centre position. Structural effects were caused by surface roughening. The sputtered surfaces formed a Pt-skeleton on the outermost layers as a result of the dissolution of transition metal atoms. A modification of Pt electronic properties altered the adsorption and catalytic properties of the corresponding bimetallic alloy. The most active systems for the oxygen reduction reaction (ORR) were observed in the Pt-skin near-surface formation. 3 refs.

  5. The morphology of coconut fiber surface under chemical treatment

    OpenAIRE

    Arsyad, Muhammad; Wardana, I Nyoman Gede; Pratikto,; Irawan, Yudy Surya

    2015-01-01

    The objective of this study was to determine the effect of chemical treatment on the coconut fiber surface morphology. This study is divided into three stages, preparation of materials, treatment and testing of coconut fiber. The first treatment is coconut fiber soaked in a solution of NaOH for 3 hours with concentration, respectively 5%, 10%, 15%, and 20%. The second treatment is coconut fiber soaked in KMnO4 solution with a concentration of 0.25%, 0.5%, 0.75%, and 1% for 3 hours. The third ...

  6. Helium effects on tungsten surface morphology and deuterium retention

    International Nuclear Information System (INIS)

    Ueda, Y.; Peng, H.Y.; Lee, H.T.; Ohno, N.; Kajita, S.; Yoshida, N.; Doerner, R.; De Temmerman, G.; Alimov, V.; Wright, G.

    2013-01-01

    Recent experimental results on tungsten surface morphology, especially nano-structure (fuzz), induced by helium plasma exposure at temperatures between 1000 K and 2000 K are reviewed. This structure was firstly reported in 2006. In this review, most of experimental results reported so far including characteristics and formation conditions of the nano-structure in both linear plasma devices and magnetic confinement devices, erosion and arcing by steady-state plasma exposure and ELM-like pulsed heat or pulsed plasma exposure by a laser and a plasma gun are summarized. In addition, He effects on D retention under simultaneous D/He irradiation on tungsten are presented

  7. Activated sludge morphology characterization through an image analysis procedure

    Directory of Open Access Journals (Sweden)

    Y. G. Perez

    2006-09-01

    Full Text Available This work deals with the development of a digital image analysis procedure to characterize microbial flocs obtained in three different WWTP: a bench-scale Sequencing Batch Reactor (SBR dealing with phenol and nitrogen biological removal, a municipal treatment unit (Ilha do Governador, Rio de Janeiro, Brazil and an industrial wastewater treatment plant (Ciba - Estrada do Colégio, Rio de Janeiro, Brazil. The developed procedure permits to obtain its morphological parameters like equivalent diameter, compactness, roundness and porosity properties as well as the fractal dimension. This procedure was validated and lead to identify the major relationships between the analysed morphological parameters. A minimum of 300 flocs should be included in the image analysis and a significant influence of the sample dilution step on the mean size of the flocs was verified. The porosity parameter positively correlated with the fractal dimension of microbial aggregates indicating the that highly porous flocs are very irregular.

  8. Surface morphology effects in a vibration based triboelectric energy harvester

    Science.gov (United States)

    Nafari, A.; Sodano, H. A.

    2018-01-01

    Despite the abundance of ambient mechanical energy in our environment, it is often neglected and left unused. However, recent studies have demonstrated that mechanical vibrations can be harvested and used to power small wireless electronic devices, such as micro electromechanical sensors (MEMS) and actuators. Most commonly, these energy harvesters convert vibration into electrical energy by utilizing piezoelectric, electromagnetic or electrostatic effects. Recently, triboelectric based energy harvesters have shown to be among the simplest and most cost-effective techniques for scavenging mechanical energy. The basis of triboelectric energy harvesters is the periodic contact and separation of two surfaces with opposite triboelectric properties which results in induced charge flow through an external load. Here, a vibration driven triboelectric nanogenerator (TENG) is fabricated and the effect of micro/nano scale surface modification is studied. The TENG produces electrical energy on the basis of periodic out-of-plane charge separation between gold and polydimethylsiloxane (PDMS) with opposite triboelectric charge polarities. By introducing micro/nano scale surface modifications to the PDMS and gold, the TENG’s power output is further enhanced. This work demonstrates that the morphology of the surfaces in a TENG device is important and by increasing the effective surface area through micro/nano scale modification, the power output of the device can increase by 118%. Moreover, it is shown that unlike many TENGs proposed in the literature, the fabricated device has a high RMS open circuit voltage and short circuit current and can perform for an extended period of time.

  9. Morphology and electronic properties of silicon carbide surfaces

    Science.gov (United States)

    Nie, Shu

    2007-12-01

    monitored using low-energy electron diffraction (LEED) and Auger electron spectroscopy, and the morphology of the graphitized surface is studied using AFM and STM. Use of H-etched SiC substrates enables a relatively flat surface morphology, although residual steps remain due to unintentional miscut of the wafers. Additionally, some surface roughness in the form of small pits is observed, possibly due to the fact that the surface treatments (H-etching and UHV annealing) having been performed in separate vacuum chambers with an intervening transfer through air. Field-effect transistors have been fabricated with our graphene layers; they show a relatively strong held effect at room temperature, with an electron mobility of 535 cm 2/Vs. This value is somewhat lower than that believed to be theoretically possible for this material, and one possible reason may be the nonideal morphology of the surface (i.e. because of the observed steps and pits). Tunneling spectra of the graphene reveal semi-metallic behavior, consistent with that theoretically expected for an isolated layer of graphene. However, additional discrete states are observed in the spectra, possibly arising from bonding at the graphene/SiC interface. The observation of these states provides important input towards an eventual determination of the complete interface structure, and additionally, such states may be relevant in determining the electron mobility of the graphene. Stepped vicinal SIC{0001} substrates are useful templates for epitaxial growth of various types of layers: thick layers of compound semiconductor (in which the steps help preserving the stacking arrangement in the overlayer), monolayers of graphene, or submonolayer semiconductor layers that form quantum wires along the step edges. Step array produced by H-etching of vicinal SiC (0001) and (0001¯) with various miscut angles have been studied by AFM. H-etching is found to produce full unit-cell-high steps on the (0001) Si-face surfaces, but half

  10. Radioactive Ions for Surface Characterization

    CERN Multimedia

    2002-01-01

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

  11. Interaction of energetic particles with polymer surfaces: surface morphology development and sputtered polymer-fragment ion analysis

    International Nuclear Information System (INIS)

    Michael, R.S.

    1987-01-01

    The core of this thesis is based on a series of papers that have been published or will soon be published in which the various processes taking place in the energetic particle-polymer surface interaction scene is investigated. Results presented show different developments on polymer surfaces when compared to the vast experimental data on energetic particle-metal surface interactions. The surface morphology development depends on the physical characteristics of the polymer. Sputtering yields of fluoropolymers were several orders higher than the sputtering yields of aliphatic and aromatic polymers. Depending on the chemical nature of the polymer, the surface morphology development was dependent upon the extent of radiation-damage accumulation. Fast Atom Bombardment Mass Spectrometry at low and high resolution was applied to the characterization of sputtered polymer fragment ions. Fragment ions and their intensities were used to identify polymer samples, observe radiation damage accumulation and probe polymer-polymer interface of a polymer-polymer sandwich structure. A model was proposed which attempts to explain the nature of processes involved in the energetic particle-polymer surface interaction region

  12. Crack layer morphology and toughness characterization in steels

    Science.gov (United States)

    Chudnovsky, A.; Bessendorf, M.

    1983-01-01

    Both the macro studies of crack layer propagation are presented. The crack extension resistance parameter R sub 1 based on the morphological study of microdefects is introduced. Experimental study of the history dependent nature of G sub c supports the representation of G sub c as a product of specific enthalpy of damage (material constant) and R sub 1. The latter accounts for the history dependence. The observation of nonmonotonic crack growth under monotonic changes of J as well as statistical features of the critical energy release rate (variance of G sub c) indicate the validity of the proposed damage characterization.

  13. Identification card and codification of the chemical and morphological characteristics of 14 dental implant surfaces.

    Science.gov (United States)

    Dohan Ehrenfest, David M; Vazquez, Lydia; Park, Yeong-Joon; Sammartino, Gilberto; Bernard, Jean-Pierre

    2011-10-01

    Dental implants are commonly used in daily practice; however, most surgeons do not really know the characteristics of these biomedical devices they are placing in their patients. The objective of this work is to describe the chemical and morphological characteristics of 14 implant surfaces available on the market and to establish a simple and clear identification (ID) card for all of them, following the classification procedure developed in the Dohan Ehrenfest et al (2010) Codification (DEC) system. Fourteen implant surfaces were characterized: TiUnite (Nobel Biocare), Ospol (Ospol), Kohno HRPS (Sweden & Martina), Osseospeed (AstraTech), Ankylos (Dentsply Friadent), MTX (Zimmer), Promote (Camlog), BTI Interna (Biotechnology Institute), EVL Plus (SERF), Twinkon Ref (Tekka), Ossean (Intra-Lock), NanoTite (Biomet 3I), SLActive (ITI Straumann), Integra-CP/NanoTite (Bicon). Three samples of each implant were analyzed. Superficial chemical composition was analyzed using X-ray photoelectron spectroscopy/electron spectroscopy for chemical analysis, and the 100 nm in-depth profile was established using Auger electron spectroscopy. The microtopography was quantified using light interferometry. The general morphology and nanotopography were evaluated using a field emission-scanning electron microscope. Finally, the characterization code of each surface was established using the DEC system, and the main characteristics of each surface were summarized in a reader-friendly ID card. From a chemical standpoint, of the 14 different surfaces, 10 were based on a commercially pure titanium (grade 2 or 4), 3 on a titanium-aluminum alloy (grade 5 titanium), and one on a calcium phosphate core. Nine surfaces presented different forms of chemical impregnation or discontinuous coating of the titanium core, and 3 surfaces were covered with residual aluminablasting particles. Twelve surfaces presented different degrees of inorganic pollutions, and 2 presented a severe organic pollution

  14. Might short term rockglacier surface morphological changes be attributed to permafrost degradation ?

    Science.gov (United States)

    Perrier, Romain; Cossart, Etienne; Fort, Monique

    2015-04-01

    In high mountain environments, permafrost is increasingly affected by climate change. Rockglaciers represent the expression of creeping permafrost: they are generally considered as good geo-indicators of cryosphere distribution and evolution. Research dealing with the effect of climate change on rockglacier degradation is mostly based on photogrammetric studies as well as geophysics. Major results on rockglaciers behavior in relation to increasing mean annual air temperature are summarized as follows. Firstly, photogrammetry analysis shows that rockglacier surface velocities are higher when the permafrost temperature and/or water content increase within the rockglacier system; this can sometimes lead to the destabilization/collapse of rockglaciers. Secondly, geophysical studies demonstrate a decrease in resistivities within the rockglacier body in relation to a decrease in ice content hence suggesting a degradation of permafrost. Although these methods are appropriate for studying the effects of climate change on mountain permafrost and rockglacier evolution, their application is fairly costly and time-consuming, and are usually restricted to one or two study cases. Our investigations over a wider area up to regional scale require completing our approach by using surface morphological changes, a method that can identify potential degradation in a warming context. In this context, this work intends to characterize short terms (multi-decades) surface morphological changes at rockglacier scale and to determine if these changes may be attributed to potential permafrost degradation. Our investigations have been carried out in both Clarée and Ubaye valleys, in the French Southern Alps. Here we present our results obtained from the Lac Rouge rockglacier (45°02'49''N, 6°30'16''E; 2600-2825m a.s.l, Clarée valley, French Southern Alps). Analysis of multi-temporal aerial photographs, geomorphological field mapping, electrical resistivity tomographies and surface

  15. Structural characterization of semicrystalline polymer morphologies by imaging-SANS

    International Nuclear Information System (INIS)

    Radulescu, A; Fetters, L J; Richter, D

    2012-01-01

    Control and optimization of polymer properties require the global knowledge of the constitutive microstructures of polymer morphologies in various conditions. The microstructural features can be typically explored over a wide length scale by combining pinhole-, focusing- and ultra-small-angle neutron scattering (SANS) techniques. Though it proved to be a successful approach, this involves major efforts related to the use of various scattering instruments and large amount of samples and the need to ensure the same crystallization kinetics for the samples investigated at various facilities, in different sample cell geometries and at different time intervals. With the installation and commissioning of the MgF 2 neutron lenses at the KWS-2 SANS diffractometer installed at the Heinz Maier-Leibnitz neutron source (FRMII reactor) in Garching, a wide Q-range, between 10 −4 Å −1 and 0.5Å −1 , can be covered at a single instrument. This enables investigation of polymer microstructures over a length scale from lnm up to 1μm, while the overall polymer morphology can be further examined up to 100μm by optical microscopy (including crossed polarizers). The study of different semi-crystalline polypropylene-based polymers in solution is discussed and the new imaging-SANS approach allowing for an unambiguous and complete structural characterization of polymer morphologies is presented.

  16. Modelling and simulation of surface morphology driven by ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Yewande, E.O.

    2006-05-02

    Non-equilibrium surfaces, at nanometer length scales, externally driven via bombardment with energetic particles are known to exhibit well ordered patterns with a variety of applications in nano-technology. These patterns emerge at time scales on the order of minutes. Continuum theory has been quite successful in giving a general picture of the processes that interplay to give the observed patterns, as well as how such competition might determine the properties of the nanostructures. However, continuum theoretical descriptions are ideal only in the asymptotic limit. The only other theoretical alternative, which happens to be more suitable for the characteristic length-and time-scales of pattern formation, is Monte Carlo simulation. In this thesis, surface morphology is studied using discrete solid-on-solid Monte Carlo models of sputtering and surface diffusion. The simulations are performed in the context of the continuum theories and experiments. In agreement with the experiments, the ripples coarsen with time and the ripple velocity exhibits a power-law behaviour with the ripple wavelength, in addition, the exponent was found to depend on the simulation temperature, which suggests future experimental studies of flux dependence. Moreover, a detailed exploration of possible topographies, for different sputtering conditions, corresponding to different materials, was performed. And different surface topographies e.g. holes, ripples, and dots, were found at oblique incidence, without sample rotation. With sample rotation no new topography was found, its only role being to destroy any inherent anisotropy in the system. (orig.)

  17. Modelling and simulation of surface morphology driven by ion bombardment

    International Nuclear Information System (INIS)

    Yewande, E.O.

    2006-01-01

    Non-equilibrium surfaces, at nanometer length scales, externally driven via bombardment with energetic particles are known to exhibit well ordered patterns with a variety of applications in nano-technology. These patterns emerge at time scales on the order of minutes. Continuum theory has been quite successful in giving a general picture of the processes that interplay to give the observed patterns, as well as how such competition might determine the properties of the nanostructures. However, continuum theoretical descriptions are ideal only in the asymptotic limit. The only other theoretical alternative, which happens to be more suitable for the characteristic length-and time-scales of pattern formation, is Monte Carlo simulation. In this thesis, surface morphology is studied using discrete solid-on-solid Monte Carlo models of sputtering and surface diffusion. The simulations are performed in the context of the continuum theories and experiments. In agreement with the experiments, the ripples coarsen with time and the ripple velocity exhibits a power-law behaviour with the ripple wavelength, in addition, the exponent was found to depend on the simulation temperature, which suggests future experimental studies of flux dependence. Moreover, a detailed exploration of possible topographies, for different sputtering conditions, corresponding to different materials, was performed. And different surface topographies e.g. holes, ripples, and dots, were found at oblique incidence, without sample rotation. With sample rotation no new topography was found, its only role being to destroy any inherent anisotropy in the system. (orig.)

  18. Couple of biomimetic surfaces with different morphologies for remanufacturing nonuniform wear rail surface

    Science.gov (United States)

    Sui, Qi; Zhou, Hong; Yang, Lin; Zhang, Haifeng; Feng, Li; Zhang, Peng

    2018-02-01

    In this work, biomimetic laser treatment was performed on repairing and remanufacturing the nonuniform worn rail surface. The wearing depth distribution of three work regions of a failure rail surface was discussed, and different thickness hardening layers with different microstructure, microhardness and wear resistances were detected from the worm surfaces. Varying wear resistances of the surfaces with different biomimetic morphologies were obtained by biomimetic laser treatments, and the corresponding effect on the lubrication sliding wear of treated and untreated surfaces were studied for comparative study. In addition, the relationship between wear resistance and the spacing of units was also provided, which can lay the important theoretical foundation for avoiding the wear resistance of the serious worn surface is less than that of the slight worn surface in the future practical applications.

  19. Controllable surface morphology and properties via mist polymerization on a plasma-treated polymethyl methacrylate surface.

    Science.gov (United States)

    Wan, S J; Wang, L; Xu, X J; Zhao, C H; Liu, X D

    2014-02-14

    Surface modification by grafting polymers on solid materials is an important strategy used to improve surface properties. This article reports that under appropriate conditions, very thin layers with desired morphologies may be constructed on a plasma-treated substrate by feeding a small quantity of a monomer with a mist stream carrying droplets produced from monomer solutions. We investigate the effects of process parameters that affect layer morphology, including exposure time to the mist stream, concentration of the monomer solution, and solvent selectivity. For a methyl methacrylate solution in ethanol, nanoparticles are uniformly grown with increasing monomer concentration or exposure time and finally form a porous layer at 3.65 mol L(-1) for 30 min. Decreasing solvent polarity not only affects surface morphology, but also increases hydrophobicity of the resulting surface. With 2,2,3,4,4,4-hexafluorobutyl methacrylate as the monomer, SEM and AFM micrographs indicated that mist polymerization results in numerous microspheres on the activated surface. These experimental results were interpreted by a mechanism in terms of an in situ polymerization accompanied by a phase transformation of the resulting polymer. Specifically, plasma treatment provides highly active cations and radicals to initiate very rapid polymerization, and the resulting polymers are consequently deposited from the liquid onto the surface under phase transition mechanisms.

  20. Optical Characterization of Nanostructured Surfaces

    DEFF Research Database (Denmark)

    Feidenhans'l, Nikolaj Agentoft

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

  1. Surfactant assisted surface morphology and thermal properties of polythiophene composites

    Science.gov (United States)

    Vijeth, H.; Niranjana, M.; Yesappa, L.; Chapi, Sharanappa; Raghu, S.; Ashokkumar, S. P.; Devendrappa, H.

    2017-06-01

    Conducting polythiophene (PTH)/aluminium oxide (Al2O3) composites was prepared with camphor sulphonic acid (CSA) as s anionic surfactant by means of in situ chemical oxidation polymerization. The morphology and material phase of PTH/Al2O3 (PTHA) composites were investigated by Field-Emission Scanning Electron Microscopy (FESEM) and Energy-dispersive X-ray spectroscopy (EDX). The FESEM image shows alter the size of grain and EDX results consistent with the presence of Al2O3 and CSA chemical composition. Thermal stability of composites was characterized using TGA/DSC, the results indicate that the PTP/Al2O3 composites have higher thermal stability than that of PTP and decompose at higher temperatures due to addition of anionic surfactant.

  2. Material, Mechanical, and Tribological Characterization of Laser-Treated Surfaces

    Science.gov (United States)

    Yilbas, Bekir Sami; Kumar, Aditya; Bhushan, Bharat; Aleem, B. J. Abdul

    2014-10-01

    Laser treatment under nitrogen assisting gas environment of cobalt-nickel-chromium-tungsten-based superalloy and high-velocity oxygen-fuel thermal spray coating of nickel-chromium-based superalloy on carbon steel was carried out to improve mechanical and tribological properties. Superalloy surface was preprepared to include B4C particles at the surface prior to the laser treatment process. Material and morphological changes in the laser-treated samples were examined using scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction (XRD) analysis. Residual stresses present at the surface region of the laser-treated layer were determined from the XRD data. The microhardness of the laser-treated surface was measured by indentation tests. Fracture toughness of the coating surfaces before and after laser treatment were also measured using overload indentation tests. Macrowear and macrofriction characterization were carried out using pin-on-disk tests.

  3. Multiscale Characterization of Joint Surface Roughness

    Science.gov (United States)

    Nigon, Benoit; Englert, Andreas; Pascal, Christophe; Saintot, Aline

    2017-12-01

    Recent studies provided detailed characterizations of fault (i.e., shear fracture) roughness at different length scales. Similar investigation for joints (i.e., tensile fractures) are seldom and not as detailed. The present study aims at characterizing joint plumose patterns. We investigated the scale-dependent surface roughness properties of S-type plumoses. Joint surface measurements at relatively large scales were carried out with Light Detection and Ranging (LiDAR) technology. Joint surface measurements at the microscopic scale were carried out based on a noncontact optical method, using a Keyence VHX-2000D microscope. Three parameters were used to characterize fracture surface elevation, standard deviation, Hurst exponent, and correlation length through 3 scale length orders of magnitude. Our study showed that standard deviation and correlation length decrease with scale, similarly to previous findings on faults. In addition, the range of Hurst exponents as a function of scale for the studied joint surface agrees well with those previously found for faults. However, directional analysis showed that correlation length and Hurst exponent of joint surfaces at scales smaller than 1 dm differ significantly from the ones of fault surfaces. In contrast to fault surface ornaments that are mainly characterized by linear structures, plumose structures show marked variability in orientation and anisotropy as a function of position on the joint surface.

  4. Microstructural characterization of oxide morphologies on Ni and Inconel foams exposed to concentrated solar radiation

    International Nuclear Information System (INIS)

    Michailidis, N.; Stergioudi, F.; Omar, H.; Pavlidou, E.; Tsipas, D.N.; Albanakis, C.; Missirlis, D.; Granier, B.

    2010-01-01

    The microstructural characterization of oxide surface morphologies formed on both high purity Ni and Inconel foams exposed to concentrated solar radiation is investigated by the use of scanning electron microscopy (SEM) and EDXS. Oxidation was achieved by concentrated solar radiation at temperatures ranging between 200 and 1100 o C for 30 min under conditions of dynamic air flow. SEM observations revealed a rapid homogeneous oxidation in the Ni-foam with three different surface oxide structures formed in relation with the process temperature. An important effect of substrate morphological and compositional features was only observed in Inconel foams, independent of the test temperature, with the existence of coarse and fine oxide regions denoting the non-uniformity of the oxidation process. The above-presented results give evidence for a potential use of the tested foam materials as volumetric solar receivers.

  5. Morphologic characterization of Mycobacterium marinum by neutron radiographic technique

    International Nuclear Information System (INIS)

    Silva, Jaqueline Michele da; Crispim, Verginia Reis; Silva, Marlei Gomes da

    2011-01-01

    The genus Mycobacterium shares many characteristics with the genera Corynebacterium and Actinomyces, among which, similar genome content of bases Guanine-Cytosine and the production of branched long-chain fatty acids called mycolic acids should be enhanced. Mycobacteria are strict aerobic, considered weakly Gram-positive, rod-shaped microorganisms, not possessing flagella. They are intracellular infecting and proliferating in the interior of macrophages, they do not form spores, produce toxins or have capsule. Optimal growth temperature and rate are variable. The genus encompasses approximately 120 known species; however, the present study focuses the characterization of Mycobacterium marinum. This species is generally pathogenic causing deep skin infections. Colonies grow slowly at temperatures around 37 degree C. The aim of this study is to speed the process of M. Marinum morphologic characterization and, in the future, apply it to other species of Nontuberculous Mycobacteria (NTM. In relation to conventional microbiologic essays that usually demand 28 days for colony growth, nuclear testing, using the neutron radiography technique, prove to be much faster. The samples were initially sterilized at the Mycobacteria Laboratory/IMPPG/UFRJ using hypochlorite solution, gluta + formaldehyde and warmed distilled water, according conventional protocols. Then, they were incubated with sodium borate, deposited over CR-39 sheets, fixed with casein (only the first and third sample) and irradiated with a thermal neutron beam generated at the J-9 channel of the Argonauta reactor from the IEN/CNEN. To this end, the following parameters were optimized: incubation time, irradiation time and CR-39 developing time. The images registered in CR-39 were visualized with the help of a Nikon E-400 optical microscope and captured with a Cool pix 995 digital camera. The results showed that the technique produces enlarged images, making it easier the morphologic characterization of

  6. Morphologic characterization of Mycobacterium marinum by neutron radiographic technique

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jaqueline Michele da; Crispim, Verginia Reis, E-mail: vrcrispim@gmail.com [Universidade Federal do Rio de Janeiro (CT/UFRJ) Centro Tecnologico, Engenharia Nuclear, RJ (Brazil); Silva, Marlei Gomes da [Universidade Federal do Rio de Janeiro (CCS/UFRJ), Centro de Ciencias da Saude. Instituto de Microbiologia Professor Paulo de Goes (Brazil)

    2011-07-01

    The genus Mycobacterium shares many characteristics with the genera Corynebacterium and Actinomyces, among which, similar genome content of bases Guanine-Cytosine and the production of branched long-chain fatty acids called mycolic acids should be enhanced. Mycobacteria are strict aerobic, considered weakly Gram-positive, rod-shaped microorganisms, not possessing flagella. They are intracellular infecting and proliferating in the interior of macrophages, they do not form spores, produce toxins or have capsule. Optimal growth temperature and rate are variable. The genus encompasses approximately 120 known species; however, the present study focuses the characterization of Mycobacterium marinum. This species is generally pathogenic causing deep skin infections. Colonies grow slowly at temperatures around 37 degree C. The aim of this study is to speed the process of M. Marinum morphologic characterization and, in the future, apply it to other species of Nontuberculous Mycobacteria (NTM. In relation to conventional microbiologic essays that usually demand 28 days for colony growth, nuclear testing, using the neutron radiography technique, prove to be much faster. The samples were initially sterilized at the Mycobacteria Laboratory/IMPPG/UFRJ using hypochlorite solution, gluta + formaldehyde and warmed distilled water, according conventional protocols. Then, they were incubated with sodium borate, deposited over CR-39 sheets, fixed with casein (only the first and third sample) and irradiated with a thermal neutron beam generated at the J-9 channel of the Argonauta reactor from the IEN/CNEN. To this end, the following parameters were optimized: incubation time, irradiation time and CR-39 developing time. The images registered in CR-39 were visualized with the help of a Nikon E-400 optical microscope and captured with a Cool pix 995 digital camera. The results showed that the technique produces enlarged images, making it easier the morphologic characterization of

  7. Fractal characterization of the coal surface

    Directory of Open Access Journals (Sweden)

    Miklúšová Viera

    1998-09-01

    Full Text Available The aim of this paper is to point up to the characterization of the brown coal using the fractal theory. On the base of BET measurements on the adsorption surface, the surface fractal dimension of crushed and milled coal samples have been determined. These values of the fractal dimension are used in the estimation of the processes by the energy input.

  8. Spectroscopic and morphologic characterization of the dentin/adhesive interface

    Science.gov (United States)

    Lemor, R. M.; Kruger, Michael B.; Wieliczka, David M.; Swafford, Jim R.; Spencer, Paulette

    1999-01-01

    The potential environmental risks associated with mercury release have forced many European countries to ban the use of dental amalgam. Alternative materials such as composite resins do not provide the clinical function for the length of time characteristically associated with dental amalgam. The weak link in the composite restoration is the dentin/adhesive bond. The purpose of this study was to correlate morphologic characterization of the dentin/adhesive bond with chemical analyses using micro- Fourier transform infrared and micro-Raman spectroscopy. A commercial dental adhesive was placed on dentin substrates cut from extracted, unerupted human third molars. Sections of the dentin/adhesive interface were investigated using infrared radiation produced at the Aladdin synchrotron source; visible radiation from a Kr+ laser was used for the micro-Raman spectroscopy. Sections of the dentin/adhesive interface, differentially stained to identify protein, mineral, and adhesive, were examined using light microscopy. Due to its limited spatial resolution and the unknown sample thickness the infrared results cannot be used quantitatively in determining the extent of diffusion. The results from the micro-Raman spectroscopy and light microscopy indicate exposed protein at the dentin/adhesive interface. Using a laser that reduces background fluorescence, the micro-Raman spectroscopy provides quantitative chemical and morphologic information on the dentin/adhesive interface. The staining procedure is sensitive to sites of pure protein and thus, complements the Raman results.

  9. MORPHOLOGICAL AND PRODUCTIVE CHARACTERIZATION OF FORAGE CACTUS VARIETIES

    Directory of Open Access Journals (Sweden)

    PHILIPE LIMA DE AMORIM

    2015-01-01

    Full Text Available Cultivars of the genus Nopalea are known in Brazil for being tolerant to cochineal carmine attacks, thus making the cultivation of this genus a promising alternative for mitigating the negative effects of this insect on the production of biomass. With the objectives of characterizing morphologically spineless forage cactus varieties and identify morphological characteristics that may be the focus in spineless forage cactus breeding programs, an experiment was conducted in a completely randomized block design with 11 treatments and four replications. The variety Alagoas showed the highest values of weight, area and volume of cladodes. The varieties Negro Michoacan F7 and V7, Tamazunchale V12 showed the highest values of the cladode area index, the total volume of cladodes and total fresh mass production. The varieties Negro Michoacan V7 and F7 presented the highest water use efficiency and dry mass yield. Cladode volume showed the highest correlation coefficients with the fresh weight of cladodes. Aiming the release of varieties for biomass production, varieties Negro Michoacan F7, V7 and Tamazunchale V12 may substitute the Miúda variety. The number and cladode area index may be used as criteria for selection of superior varieties in breeding programs.

  10. Morphological-anatomical characterization and identification of Tomentella ectomycorrhizas.

    Science.gov (United States)

    Jakucs, Erzsébet; Eros-Honti, Zsolt

    2008-09-01

    Over the last two decades, much information has been gathered on the ectomycorrhizal fungus community composition of plant associations of boreal, temperate, and tropical regions. Worldwide, Tomentella ectomycorrhizas (ECM) are often common and dominant in the mycorrhizosphere of coniferous and deciduous forests. They are present under different environmental conditions and associate with diverse plant hosts. Tomentella sporocarps, however, are rarely found aboveground, so Tomentella species are often missing from fungus community studies based on fruit-body presence. Tomentella is a resupinate genus of Thelephoraceae (Basidiomycota) forming black-brown, brown, yellow, or ochre ECM on the roots of gymnosperm and angiosperm trees, distinguished by typical morphological-anatomical characteristics (clamped hyphae, angular mantle, surface network, special rhizomorphs and cystidia). In this paper, we review the taxonomic position and morphological-anatomical characteristics of Tomentella ECM. A short summary of the microscopic features used for distinguishing tomentelloids during morphotyping and identification is presented in order to support molecular and ecological studies of ectomycorrhizal fungus communities.

  11. Bulk and surface characterization of novel photoresponsive polymeric systems

    Science.gov (United States)

    Venkataramani, Shivshankar

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

  12. Tailoring of morphology and surface properties of syndiotactic polystyrene aerogels.

    Science.gov (United States)

    Wang, Xiao; Jana, Sadhan C

    2013-05-07

    This study evaluates a method for rendering syndiotactic polystyrene (sPS) aerogels hydrophilic using polyethylene oxide (PEO) of different molecular weights. The highly porous sPS aerogels are inherently hydrophobic although applications involving absorption of moisture and removal of particulate solids may benefit from the high surface area of sPS aerogels provided some degree of hydrophilicity is induced in these materials. In this work, sPS gels are prepared by thermo-reversible gelation in tetrahydrofuran in the presence of PEO. The gels are dried under supercritical conditions to obtain aerogels. The aerogels are characterized by scanning electron microscopy, nitrogen-adsorption porosimetry, helium pycnometry, and contact angle measurements. The data reveal that the pore structures and surface energy can be controlled by varying the concentration and molecular weight of PEO and using different cooling rates during thermo-reversible gelation. In the first case, sPS aerogels, aerogels containing PEO of a low molecular weight or low concentration show superhydrophobic surface presenting the "lotus effect". In the second case, PEO at a higher concentration or with higher molecular weight forms phase-separated domains yielding new hydrophilic macropores (>10 μm) in the aerogel structures. These macropores contribute to the superhydrophobic surface with the "petal effect". The cooling rate during gelation shows a strong influence on these two cases.

  13. Surface characterization of self-assembled N-Cu nanostructures

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-01

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

  14. Effects of surface morphology on the optical and electrical properties of Schottky diodes of CBD deposited ZnO nanostructures

    Science.gov (United States)

    Mwankemwa, Benard S.; Akinkuade, Shadrach; Maabong, Kelebogile; Nel, Jackie M.; Diale, Mmantsae

    2018-04-01

    We report on effect of surface morphology on the optical and electrical properties of chemical bath deposited Zinc oxide (ZnO) nanostructures. ZnO nanostructures were deposited on the seeded conducting indium doped tin oxide substrate positioned in three different directions in the growth solution. Field emission scanning electron microscopy was used to evaluate the morphological properties of the synthesized nanostructures and revealed that the positioning of the substrate in the growth solution affects the surface morphology of the nanostructures. The optical absorbance, photoluminescence and Raman spectroscopy of the resulting nanostructures are discussed. The electrical characterization of the Schottky diode such as barrier height, ideality factor, rectification ratios, reverse saturation current and series resistance were found to depend on the nanostructures morphology. In addition, current transport mechanism in the higher forward bias of the Schottky diode was studied and space charge limited current was found to be the dominant transport mechanism in all samples.

  15. Effects of decontamination solutions on the surface of titanium: investigation of surface morphology, composition, and roughness.

    Science.gov (United States)

    Wheelis, Sutton E; Gindri, Izabelle M; Valderrama, Pilar; Wilson, Thomas G; Huang, Jessica; Rodrigues, Danieli C

    2016-03-01

    To investigate the impact of treatments used to detoxify dental implants on the oxide layer morphology and to infer how changes in morphology created by these treatments may impact re-osseointegration of an implant. Pure titanium (cpTi) and the alloy Ti6Al4V were subjected to a series of chemical treatments and mechanical abrasion simulating surface decontamination of dental implants. The morphology and roughness of the surface layer before and after treatment with these solutions were investigated with optical and atomic force microscopy (OM, AFM). The solutions employed are typically used for detoxification of dental implants. These included citric acid, 15% hydrogen peroxide, chlorhexidine gluconate, tetracycline, doxycycline, sodium fluoride, peroxyacetic acid, and treatment with carbon dioxide laser. The treatments consisted of both immersions of samples in solution and rubbing with cotton swabs soaked in solution for 1, 2, and 5 min. Cotton swabs used were analyzed with energy dispersive spectroscopy (EDS). The microscopy investigation showed that corrosion and pitting of the samples were present in both metal grades with immersion and rubbing methods when employing more acidic solutions, which had pH acidic solutions caused surface discoloration when coupled with rubbing but did not cause corrosion with immersion. Neutral or basic treatments resulted in no signs of corrosion with both methods. EDS results revealed the presence of titanium particles on all rubbing samples. It was demonstrated in this study that acidic environments coupled with rubbing are able to introduce noticeable morphological changes and corrosion on the surface of both titanium grades. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Morphological characteristics of primary enamel surfaces versus permanent enamel surfaces: SEM digital analysis.

    Science.gov (United States)

    Lucchese, A; Storti, E

    2011-09-01

    The morphology of permanent and primary enamel surface merits further analysis. The objective of this study was to illustrate a method of SEM digital image processing able to quantify and discriminate between the morphological characteristics of primary and permanent tooth enamel. Sixteen extracted teeth, 8 primary teeth and 8 permanent teeth, kept in saline solution, were analysed. The teeth were observed under SEM. The SEM images were analysed by means of digitally processed algorithms. The two algorithms used were: Local standard deviation to measure surface roughness with the roughness index (RI); Hough's theorem to identify linear structures with the linear structure index (LSI). The SEM images of primary teeth enamel show smooth enamel with little areas of irregularity. No linear structures are apparent. The SEM images of permanent enamel show a not perfectly smooth surface; there are furrows and irregularities of variable depth and width. In the clinical practice a number of different situations require the removal of a thin layer of enamel. Only a good morphological knowledge of both permanent and primary tooth enamel gives the opportunity to identify and exploit the effects of rotary tools on enamel, thus allowing for a correct finishing technique.

  17. Impact of morphology on diffusive dynamics on curved surfaces.

    Science.gov (United States)

    Kusters, Remy; Storm, Cornelis

    2014-03-01

    Diffusive processes on nonplanar substrates are deeply relevant for cellular function and transport and increasingly used to probe and characterize the behavior of proteins in membranes. We present analytical and numerical analyses of in-plane diffusion of discrete particles on curved geometries reflecting various generic motifs in biology and explore, in particular, the effect that the shape of the substrate has on the characteristic time scales of diffusive processes. To this end, we consider both collective measures (the relaxation of concentration profiles towards equilibrium) and single-particle measures (escape rates and first passage times of individual diffusing molecules): the first relevant for the correct interpretation of FRAP experiments in curved environments; the second, for single-particle tracking probes. Each of these measures is sensitively affected by the morphology of the substrate, and we find that the exit rate out of a domain is not uniquely set by the size of its boundary, illustrating the general principle we reveal: By varying the shape of a substrate, Nature can control the diffusive time scales in a microenvironment without changing the bare substrate properties.

  18. Impact of morphology on diffusive dynamics on curved surfaces

    Science.gov (United States)

    Kusters, Remy; Storm, Cornelis

    2014-03-01

    Diffusive processes on nonplanar substrates are deeply relevant for cellular function and transport and increasingly used to probe and characterize the behavior of proteins in membranes. We present analytical and numerical analyses of in-plane diffusion of discrete particles on curved geometries reflecting various generic motifs in biology and explore, in particular, the effect that the shape of the substrate has on the characteristic time scales of diffusive processes. To this end, we consider both collective measures (the relaxation of concentration profiles towards equilibrium) and single-particle measures (escape rates and first passage times of individual diffusing molecules): the first relevant for the correct interpretation of FRAP experiments in curved environments; the second, for single-particle tracking probes. Each of these measures is sensitively affected by the morphology of the substrate, and we find that the exit rate out of a domain is not uniquely set by the size of its boundary, illustrating the general principle we reveal: By varying the shape of a substrate, Nature can control the diffusive time scales in a microenvironment without changing the bare substrate properties.

  19. Surface and subsurface layers characterization in artworks using conoscopic laser holography and acoustic microscopy

    Science.gov (United States)

    Marchioro, Giacomo; Apostolidis, Georgios; Karagiannis, Georgios; Galeotti, Monica; Daffara, Claudia

    2017-07-01

    The characterization of the surface morphology and the material layers stratigraphy is a pivotal step in several stages of the conservation process of the artwork. Generally, optimal characterization of the surface cannot be achieved using a single technique but is not always possible to find techniques that can be coupled effectively. Surface maps were retrieved using acoustic microscopy and conoscopic laser holography over a set of reference samples. The surface maps compared for showing possible way to better characterize the surface morphology when their information is combined. The final data give us a more complete surface and subsurface digitalization while the results obtained are discussed highlighting the main pros and cons of the two techniques. Thus besides having insights on the effectiveness and on the performance of the processes, it is also evident that uncertainties associated with the measurement can be overcome and a single more accurate representation of the surface can be derived using both scanning methods.

  20. Effect of various tooth whitening modalities on microhardness, surface roughness and surface morphology of the enamel.

    Science.gov (United States)

    Kwon, So Ran; Kurti, Steven R; Oyoyo, Udochukwu; Li, Yiming

    2015-09-01

    The purpose of this study was to evaluate the effect of four whitening modalities on surface enamel as assessed with microhardness tester, profilometer, and scanning electron microscopy (SEM). Whitening was performed according to manufacturer's directions for over-the-counter (OTC), dentist dispensed for home use (HW) and in-office (OW) whitening. Do-it-yourself (DIY) whitening consisted of a strawberry and baking soda mix. Additionally, negative and positive controls were used. A total of 120 enamel specimens were used for microhardness testing at baseline and post-whitening. Following microhardness testing specimens were prepared for SEM observations. A total of 120 enamel specimens were used for surface roughness testing at baseline and post-whitening (n = 20 per group). Rank-based Analysis of Covariance was performed to compare microhardness and surface roughness changes. Tests of hypotheses were two-sided with α = 0.05. There was a significant difference in Knoop hardness changes (ΔKHN) among the groups (Kruskal-Wallis test, p < 0.0001). Significant hardness reduction was observed in the positive control and DIY group (p < 0.0001). Mean surface roughness changes (ΔRa) were significantly different among the groups (Kruskal-Wallis test, p < 0.0001). Surface roughness increased in the OTC group (p = 0.03) and in the positive control (p < 0.0001). The four whitening modalities-DIY, OTC, HW and OW induced minimal surface morphology changes when observed with SEM. It can be concluded that none of the four whitening modalities adversely affected enamel surface morphology. However, caution should be advised when using a DIY regimen as it may affect enamel microhardness and an OTC product as it has the potential to increase surface roughness.

  1. Annealing assisted structural and surface morphological changes in Langmuir–Blodgett films of nickel octabutoxy phthalocyanine

    Energy Technology Data Exchange (ETDEWEB)

    Shilpa Harish, T.; Viswanath, P., E-mail: viswanath@cnsms.res.in

    2016-01-01

    We report our studies on thin films of metallo-phthalocyanine (MPc), Nickel(II)1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (NiPc(OBu){sub 8}) transferred in a well defined thermodynamic state over a self assembled monolayer (octadecyl trichlorosilane)/SiO{sub 2}/Si substrate using the Langmuir–Blodgett (LB) method. The films are characterized using differential scanning calorimetry (DSC), grazing incidence X-ray diffraction (GIXD) and atomic force microscopy (AFM) techniques. DSC studies on powdered samples in the bulk indicate enantiotropic solid–solid phase transition. GIXD studies on the as-deposited LB film show a Bragg peak indicating crystallinity of the thin film. Annealing (373 K) results in reduction of lattice spacing (1.21 Å) signifying changes in molecular packing within the unit cell. At this stage, an additional Bragg peak is observed which grows at the expense of the former one and they coexist between 373 K and 423 K. A discontinuity in lattice spacing from 20.73 to 15.12 Å with annealing indicates clearly a structural change of the underlying crystalline lattice. Correspondingly, the surface morphology images obtained using AFM show, with annealing, a transformation from spherical granular morphology to elongated, flat crystallites suggesting asymmetric growth process. Statistical parameters of the grain extracted from the AFM images show that the size, fractal dimension and circularity are affected by annealing. Based on these studies, we infer the structural and surface morphological changes of the meta-stable phase (Form I) to the stable phase (Form II) in annealed LB films of phthalocyanine. - Highlights: • Langmuir–Blodgett (LB) films of phthalocyanine subjected to thermal annealing. • Structural transformation and coexistence of polymorphs in LB films • Surface morphology changes from nanoscale grains to elongated crystallites. • Reduction of fractal dimension and circularity index reveals asymmetric growth.

  2. Modeling and characterization of wavefront morphologies of laser induced damages on dielectric coating

    Science.gov (United States)

    Zheng, Yi; Liu, Zhichao; Luo, Jin; Pan, Feng; Wang, Jian; Xu, Qiao

    2017-11-01

    The specific morphologies of laser induced damages on dielectric coating can cause wavefront modulations and influence the downstream propagation properties of transmitted beam, which is so called wavefront morphologies. In this paper, the modeling and characterization of these wavefront morphologies are carried out. In theory, the modulation effects of different morphologies are discussed and their influence on downstream beam propagation properties are simulated based on diffraction integral. In experiment, a pump-and-probe system is developed to characterize different wavefront morphologies, and in correspondence, their geometric morphologies are characterized by microscopic instruments. The simulation and experiment match well with each other, and the geometric characterization explains the origins of wavefront properties of different morphologies.

  3. The nucleus of Comet Borrelly: A study of morphology and surface brightness

    Science.gov (United States)

    Oberst, J.; Howington-Kraus, E.; Kirk, R.; Soderblom, L.; Buratti, B.; Hicks, M.; Nelson, R.; Britt, D.

    2004-01-01

    Stereo images obtained during the DS1 flyby were analyzed to derive a topographic model for the nucleus of Comet 19P/Borrelly for morphologic and photometric studies. The elongated nucleus has an overall concave shape, resembling a peanut, with the lower end tilted towards the camera. The bimodal character of surface-slopes and curvatures support the idea that the nucleus is a gravitational aggregate, consisting of two fragments in contact. Our photometric modeling suggests that topographic shading effects on Borrelly's surface are very minor (the given resolution of the terrain model. Instead, albedo effects are thought to dominate Borrelly's large variations in surface brightness. With 90% of the visible surface having single scattering albedos between 0.008 and 0.024, Borrelly is confirmed to be among the darkest of the known Solar System objects. Photometrically corrected images emphasize that the nucleus has distinct, contiguous terrains covered with either bright or dark, smooth or mottled materials. Also, mapping of the changes in surface brightness with phase angle suggests that terrain roughness at subpixel scale is not uniform over the nucleus. High surface roughness is noted in particular near the transition between the upper and lower end of the nucleus, as well as near the presumed source region of Borrelly's main jets. Borrelly's surface is complex and characterized by distinct types of materials that have different compositional and/or physical properties. ?? 2003 Elsevier Inc. All rights reserved.

  4. Assessment of bracket surface morphology and dimensional change

    Directory of Open Access Journals (Sweden)

    Pillai Devu Radhakrishnan

    2017-01-01

    Full Text Available Objective: The objective of this study was to compare the surface morphology and dimensional stability of the bracket slot at the onset of treatment and after 12 months of intraoral exposure. The study also compared the amount of calcium at the bracket base which indicates enamel loss among the three orthodontic brackets following debonding after 12 months of intraoral exposure. Materials and Methods: The sample consisted of 60 (0.022” MBT canine brackets. They were divided into three groups: self-ligating, ceramic bracket with metal slot, and stainless steel (SS brackets. The slot dimensions, micromorphologic characteristics of as-received and retrieved brackets were measured with a stereomicroscope and scanning electron microscope (SEM, respectively. The amount of calcium at the bracket base which indicates enamel damage was quantified using energy-dispersive X-ray spectrometry (EDX. Results: The results showed statistically significant alterations (P < 0.05 in the right vertical dimension, internal tie wing width (cervical, right and left depth of the slot (Kruskal–Wallis test. Multiple comparison using Mann–Whitney test showed that ceramic brackets underwent (P < 0.05 minimal alterations in the right vertical dimension, internal tie wing width (cervical, right and left depth of the slot (0.01 mm, −0.003 mm, 0.006 mm, −0.002 mm, respectively when compared with the changes seen in SS and self-ligating brackets. SEM analysis revealed an increase in the surface roughness of ceramic with metal slot brackets and self-ligating bracket showed the least irregularity. The presence of calcium was noted on all evaluated brackets under EDX, but ceramic with metal slot brackets showed a significantly greater amount of enamel loss (P = 0.001. Conclusion: Ceramic brackets were found to be dimensionally stable when compared to SS and self-ligating. Self-ligating bracket showed minimal surface irregularity. Ceramic with metal slot brackets showed a

  5. Surface science tools for nanomaterials characterization

    CERN Document Server

    2015-01-01

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

  6. Nanostructured Polypyrrole Powder: A Structural and Morphological Characterization

    Directory of Open Access Journals (Sweden)

    Edgar A. Sanches

    2015-01-01

    Full Text Available Polypyrrole (PPY powder was chemically synthesized using ferric chloride (FeCl3 and characterized by X-ray diffraction (XRD, Le Bail Method, Fourier Transform Infrared Spectrometry (FTIR, and Scanning Electron Microscopy (SEM. XRD pattern showed a broad scattering of a semicrystalline structure composed of main broad peaks centered at 2θ = 11.4°, 22.1°, and 43.3°. Crystallinity percentage was estimated by the ratio between the sums of the peak areas to the area of amorphous broad halo due to the amorphous phase and showed that PPY has around 20 (1%. FTIR analysis allowed assigning characteristic absorption bands in the structure of PPY. SEM showed micrometric particles of varying sizes with morphologies similar to cauliflower. Crystal data (monoclinic, space group P 21/c, a=7.1499 (2 Å, b=13.9470 (2 Å, c=17.3316 (2 Å, α=90 Å, β=61.5640 (2 Å and γ=90 Å were obtained using the FullProf package program under the conditions of the method proposed by Le Bail. Molecular relaxation was performed using the density functional theory (DFT and suggests that tetramer polymer chains are arranged along the “c” direction. Average crystallite size was found in the range of 20 (1 Å. A value of 9.33 × 10−9 S/cm was found for PPY conductivity.

  7. Effect of lactic acid on nucleation morphology and surface ...

    Indian Academy of Sciences (India)

    Deposition process started at some initial priority growing centres independently distributed on the substrate. We found that the morphology and ... agent in the bath solution, morphology of initial deposition centres change from coniform ... control the rate of release of free metal ions for the reduction reaction. The chemical ...

  8. Morphological characterization of a human glioma cell l ine.

    Science.gov (United States)

    Machado, Camila Ml; Schenka, André; Vassallo, José; Tamashiro, Wirla Msc; Gonçalves, Estela M; Genari, Selma C; Verinaud, Liana

    2005-05-10

    A human malignant continuous cell line, named NG97, was recently established in our laboratory. This cell line has been serially subcultured over 100 times in standard culture media presenting no sign of cell senescence. The NG97 cell line has a doubling time of about 24 h. Immunocytochemical analysis of glial markers demonstrated that cells are positive for glial fibrillary acidic protein (GFAP) and S-100 protein, and negative for vimentin. Under phase-contrast microscope, cultures of NG97 showed cells with variable morphological features, such as small rounded cells, fusiform cells (fibroblastic-like cells), and dendritic-like cells. However, at confluence just small rounded and fusiform cells can be observed. At scanning electron microscopy (SEM) small rounded cells showed heterogeneous microextentions, including blebs and filopodia. Dendritic-like cells were flat and presented extensive prolongations, making several contacts with small rounded cells, while fusiform cells presented their surfaces dominated by microvilli.We believe that the knowledge about NG97 cell line may be useful for a deeper understanding of biological and immunological characteristics of gliomas.

  9. Scattered surface charge density: A tool for surface characterization

    KAUST Repository

    Naydenov, Borislav

    2011-11-28

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

  10. Bi-stage time evolution of nano-morphology on inductively coupled plasma etched fused silica surface caused by surface morphological transformation

    Science.gov (United States)

    Jiang, Xiaolong; Zhang, Lijuan; Bai, Yang; Liu, Ying; Liu, Zhengkun; Qiu, Keqiang; Liao, Wei; Zhang, Chuanchao; Yang, Ke; Chen, Jing; Jiang, Yilan; Yuan, Xiaodong

    2017-07-01

    In this work, we experimentally investigate the surface nano-roughness during the inductively coupled plasma etching of fused silica, and discover a novel bi-stage time evolution of surface nano-morphology. At the beginning, the rms roughness, correlation length and nano-mound dimensions increase linearly and rapidly with etching time. At the second stage, the roughening process slows down dramatically. The switch of evolution stage synchronizes with the morphological change from dual-scale roughness comprising long wavelength underlying surface and superimposed nano-mounds to one scale of nano-mounds. A theoretical model based on surface morphological change is proposed. The key idea is that at the beginning, etched surface is dual-scale, and both larger deposition rate of etch inhibitors and better plasma etching resistance at the surface peaks than surface valleys contribute to the roughness development. After surface morphology transforming into one-scale, the difference of plasma resistance between surface peaks and valleys vanishes, thus the roughening process slows down.

  11. Spatial and temporal changes in the morphology of preosteoblastic cells seeded on microstructured tantalum surfaces

    DEFF Research Database (Denmark)

    Justesen, Jørn; Lorentzen, M.; Andersen, L. K.

    2009-01-01

    It has been widely reported that surface morphology on the micrometer scale affects cell function as well as cell shape. In this study, we have systematically compared the influence of 13 topographically micropatterned tantalum surfaces on the temporal development of morphology, including spreadi...

  12. Electrochemical characterization of organosilane-functionalized nanostructured ITO surfaces

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-08

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

  13. Electrochemical characterization of organosilane-functionalized nanostructured ITO surfaces

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  14. Effect of surface topography and morphology on space charge packets in polyethylene

    International Nuclear Information System (INIS)

    Zhou Yuanxiang; Wang Yunshan; Sun Qinghua; Wang Ninghua

    2009-01-01

    Polyethylene (PE) is a major kind of internal insulating material. With great progresses of space charge measurement technologies in the last three decades, lots of researches are focused on space charge in PE. The heat pressing and annealing condition of polyethylene affect its morphology obviously. During the heat pressing, the surface of PE forms different surface topographies because of different substrate materials. Surface topography has great relation to the epitaxial crystallization layer and influences the space charge characteristic of PE dramatically. This paper studied the formation process of different surface topographies and their micrographic characters in low density polyethylene (LDPE). pulsed electro-acoustic (PEA) method was used to measure the space charge distribution of samples with different surface topographies and morphologies in LDPE. The effect of surface topography and morphology to space charge packet were studied. The surface topography has great influence on space charge packet polarity and morphology has influence on both movement speed rate and polarity of space charge packet.

  15. A Robotic Platform for Corn Seedling Morphological Traits Characterization

    Science.gov (United States)

    Lu, Hang; Tang, Lie; Whitham, Steven A.; Mei, Yu

    2017-01-01

    Crop breeding plays an important role in modern agriculture, improving plant performance, and increasing yield. Identifying the genes that are responsible for beneficial traits greatly facilitates plant breeding efforts for increasing crop production. However, associating genes and their functions with agronomic traits requires researchers to observe, measure, record, and analyze phenotypes of large numbers of plants, a repetitive and error-prone job if performed manually. An automated seedling phenotyping system aimed at replacing manual measurement, reducing sampling time, and increasing the allowable work time is thus highly valuable. Toward this goal, we developed an automated corn seedling phenotyping platform based on a time-of-flight of light (ToF) camera and an industrial robot arm. A ToF camera is mounted on the end effector of the robot arm. The arm positions the ToF camera at different viewpoints for acquiring 3D point cloud data. A camera-to-arm transformation matrix was calculated using a hand-eye calibration procedure and applied to transfer different viewpoints into an arm-based coordinate frame. Point cloud data filters were developed to remove the noise in the background and in the merged seedling point clouds. A 3D-to-2D projection and an x-axis pixel density distribution method were used to segment the stem and leaves. Finally, separated leaves were fitted with 3D curves for morphological traits characterization. This platform was tested on a sample of 60 corn plants at their early growth stages with between two to five leaves. The error ratios of the stem height and leave length measurements are 13.7% and 13.1%, respectively, demonstrating the feasibility of this robotic system for automated corn seedling phenotyping. PMID:28895892

  16. A Robotic Platform for Corn Seedling Morphological Traits Characterization.

    Science.gov (United States)

    Lu, Hang; Tang, Lie; Whitham, Steven A; Mei, Yu

    2017-09-12

    Crop breeding plays an important role in modern agriculture, improving plant performance, and increasing yield. Identifying the genes that are responsible for beneficial traits greatly facilitates plant breeding efforts for increasing crop production. However, associating genes and their functions with agronomic traits requires researchers to observe, measure, record, and analyze phenotypes of large numbers of plants, a repetitive and error-prone job if performed manually. An automated seedling phenotyping system aimed at replacing manual measurement, reducing sampling time, and increasing the allowable work time is thus highly valuable. Toward this goal, we developed an automated corn seedling phenotyping platform based on a time-of-flight of light (ToF) camera and an industrial robot arm. A ToF camera is mounted on the end effector of the robot arm. The arm positions the ToF camera at different viewpoints for acquiring 3D point cloud data. A camera-to-arm transformation matrix was calculated using a hand-eye calibration procedure and applied to transfer different viewpoints into an arm-based coordinate frame. Point cloud data filters were developed to remove the noise in the background and in the merged seedling point clouds. A 3D-to-2D projection and an x -axis pixel density distribution method were used to segment the stem and leaves. Finally, separated leaves were fitted with 3D curves for morphological traits characterization. This platform was tested on a sample of 60 corn plants at their early growth stages with between two to five leaves. The error ratios of the stem height and leave length measurements are 13.7% and 13.1%, respectively, demonstrating the feasibility of this robotic system for automated corn seedling phenotyping.

  17. Effect of Deposition Rate on Structure and Surface Morphology of Thin Evaporated Al Films on Dielectrics and Semiconductors

    DEFF Research Database (Denmark)

    Bordo, K.; Rubahn, H. G.

    2012-01-01

    . The structure and surface morphology of the as-deposited Al films were studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM imaging of the films showed that the mean grain size of thin Al films on all of the substrates increased from 20 nm - 30 nm to 50 nm - 70 nm...... with increase of the deposition rate. Quantitative AFM characterization showed that for all substrates the root mean square surface roughness increases monotonically with increasing the deposition rate from 0.1 nm/s to 2 nm/s. The observed effects of the deposition rate on the grain size and surface roughness...

  18. Surface morphology influence on deuterium retention in beryllium films prepared by thermionic vacuum arc method

    International Nuclear Information System (INIS)

    Anghel, A.; Porosnicu, C.; Badulescu, M.; Mustata, I.; Lungu, C.P.; Sugiyama, K.; Lindig, S.; Krieger, K.; Roth, J.; Nastuta, A.; Rusu, G.; Popa, G.

    2009-01-01

    In a plasma-confinement device, material eroded from plasma facing components will be transported and re-deposited at other locations inside the reaction chamber. Since beryllium from the first wall of the ITER fusion reactor will be eroded, ionized in the scrape-off layer plasma and finally re-deposited on divertor surfaces flowing along the magnetic field, it is important to study the properties of divertor armour materials (C, W) coated with beryllium. By applying different bias voltages (-200 V to +700 V) to the substrates during deposition, the morphology of the obtained films was modified. The films' morphology was characterized by means of AFM and SEM, and it was found that the coatings prepared using negative bias voltage at the substrate during deposition are more compact and have a smoother surface compared to the samples prepared with positive bias voltage. The thickness and composition of each film were measured using Rutherford backscattering spectrometry (RBS). A study of deuterium implantation and retention into the prepared films was performed at IPP Garching in the high current ion source.

  19. Surface characterization of low-temperature grown yttrium oxide

    Science.gov (United States)

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

    2018-04-01

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

  20. Modeling three-dimensional surface morphology of biocake layer in a membrane bioreactor based on fractal geometry.

    Science.gov (United States)

    Zhao, Leihong; Yang, Lining; Lin, Hongjun; Zhang, Meijia; Yu, Haiying; Liao, Bao-Qiang; Wang, Fangyuan; Zhou, Xiaoling; Li, Renjie

    2016-12-01

    While the adsorptive fouling in membrane bioreactors (MBRs) is highly dependent of the surface morphology, little progress has been made on modeling biocake layer surface morphology. In this study, a novel method, which combined static light scattering method for fractal dimension (D f ) measurement with fractal method represented by the modified two-variable Weierstrass-Mandelbrot function, was proposed to model biocake layer surface in a MBR. Characterization by atomic force microscopy showed that the biocake surface was stochastic, disorder, self-similarity, and with non-integer dimension, illustrating obvious fractal features. Fractal dimension (D f ) of sludge suspension experienced a significant change with operation of the MBR. The constructed biocake layer surface by the proposed method was quite close to the real surface, showing the feasibility of the proposed method. It was found that D f was the critical factor affecting surface morphology, while other factors exerted moderate or minor effects on the roughness of biocake layer. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Mechanism of action of pefloxacin on surface morphology, DNA ...

    African Journals Online (AJOL)

    work-group

    2011-11-16

    Nov 16, 2011 ... Department of Life Sciences, Applied Microbiology Laboratory, University of Mumbai, Vidyanagari, Santacruz (E),. Mumbai 400098 ... The MIC determined by broth dilution method and Hi-Comb method was 0.1 µg/ml. Morphological ... against Gram-negative bacteria involved in UTI, the quinolone class has ...

  2. Morphology, surface topography and optical studies on electron ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 29; Issue 5. Morphology ... Their AFM images exhibit columnar/pyramidal/truncated cone structure, providing support to the 3D Stranski–Krastanov model for film growth. Further, they ... Materials Science Programme, Indian Institute of Technology, Kanpur 208 016, India ...

  3. Influence of multi-wavelength laser irradiation of enamel and dentin surfaces on surface morphology and permeability

    Science.gov (United States)

    Chang, Nai-Yuan N.; Jew, Jamison; Simon, Jacob C.; Chan, Kenneth H.; Lee, Robert C.; Fried, William A.; Cho, Jinny; Darling, Cynthia L.; Fried, Daniel

    2017-02-01

    UV and IR lasers can be used to specifically target protein, water, and the mineral phase of dental hard tissues to produce varying changes in surface morphology. In this study, we irradiated enamel and dentin surfaces with various combinations of lasers operating at 0.355, 2.94, and 9.4 μm, exposed those surfaces to topical fluoride, and subsequently evaluated the influence of these changes on surface morphology and permeability. Digital microscopy and surface dehydration rate measurements were used to monitor changes in the samples overtime. The surface morphology and permeability (dehydration rate) varied markedly with the different laser treatments on enamel. On dentin, fluoride was most effective in reducing the permeability.

  4. Infrared active thermography for surface layer characterization

    International Nuclear Information System (INIS)

    Semerok, A.; Fomichev, S.; Farcage, D.; Sortais, C.; Courtois, X.

    2006-05-01

    Deposited layer characterization was stated as the main goal of our studies for 2006. The investigations by DRFC/SIPP/GCFP (CEA Cadarache) were performed with the procedure of surface temperature measurements based on infrared thermography with synchronous demodulation (Lock-in Thermography). It was applied to provide the temperature surface monitoring during the modulated heating by illumination. The obtained 2D-cartography revealed the zones with a weak heat transfer resulting from a low layer/surface adhesion or poor layer thermal conductivity. The obtained lock-in cartography data should be regarded only as qualitative. For deposited layers characterization (layer depth, adhesion with the substrate), the active laser pyrometer measurements with the developed experimental device were made in LILM laboratory (CEA Saclay). Active surface pyrometry with repetitive laser heating can provide both qualitative and quantitative data on the first layer and the interface with the substrate. A 3D-numerical model of graphite deposited layer heating by a pulsed high repetition rate laser beam was developed to determine the heated surface temperature with a high temporal and spatial resolution. The theoretical data obtained with 3D-numerical model for surface heating were compared with the experimental results. It was demonstrated that for the given optical and thermo-physical parameters of materials, the theoretical temperatures may be fitted with the experimental results to assess certain unknown parameters of the layer (thermal contact resistance, diffusivity, thickness, porosity, ). Based on the comparison of the obtained experimental and theoretical results, the deposited layer characterization was made. The results of the investigations on Active Laser Pyrometry and Lock-in Thermography demonstrated that the methods can provide qualitative and quantitative data on the deposited layer and on the layer/substrate interface. The correlation and cross-check of the results

  5. Characterizing the statistical properties of protein surfaces

    Science.gov (United States)

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

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

  6. Characterization of electrochemically modified polycrystalline platinum surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Krebs, L.C.; Ishida, Takanobu.

    1991-12-01

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

  7. Characterization of electrochemically modified polycrystalline platinum surfaces

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-12-01

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

  8. Surface microstructure of bitumen characterized by atomic force microscopy.

    Science.gov (United States)

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

    2015-04-01

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

  9. Colour interceptions, thermal stability and surface morphology of polyester metal complexes

    International Nuclear Information System (INIS)

    Zohdy, M.H.

    2005-01-01

    Chelating copolymers via grafting of acrylic acid (AAc) and acrylamide (AAm/AAc) comonomer mixture onto polyester micro fiber fabrics (PETMF) using gamma-radiation technique were prepared. The prepared graft chains (PETMF-g-AAc) and (PETMF-g-PAAc/PAAm) acted as chelating sites for some selected transition metal ions. The prepared graft copolymers and their metal complexes were characterized using thermogravimetric analysis (TGA), colour parameters and surface morphology measurements. The colour interception and strength measurements showed that the metal complexation is homogeneously distributed. The results showed that the thermal stability of PETMF was improved after graft copolymerization and metal complexes. Moreover, the degree of grafting enhanced the thermal stability values of the grafted and complexed copolymers up to 25% of magnitude, on the other hand the activation energy of the grafted-copolymer with acrylic acid increased up to 80%. The SEM observation gives further supports to the homogenous distribution of grafting and metal complexation

  10. Decalin-assisted light emitting porous Si formation and its optical, surface and morphological properties

    Science.gov (United States)

    Karatutlu, Ali; Istengir, Sumeyra; Cosgun, Sedat; Seker, Isa; Unal, Bayram

    2017-11-01

    In this research paper, light emitting porous silicon (Lep-Si) samples were fabricated by a surfactant-mediated chemical stain etching solution in order to form homogenous luminescent nanostructures at room temperature. As an industrially important solvent, decalin (decahydronaphtalene) was used as a surfactant in the HF/HNO3 solutions in order to control the etching process. Morphological, surface and optical properties of the Lep-Si samples were examined using atomic force microscopy, X-ray photoelectron spectroscopy, photoluminescence (PL) spectroscopy, and laser scanning confocal microscopy (LSCM) techniques. These characterization techniques were correlated with the various etching times including depth dependent luminescence profiles for the first time. We report the optimum conditions for production of the most efficient Lep-Si using decalin (decahydronaphtalene) and possible structural origins of light emission using the depth dependent luminescence measurements.

  11. Manipulating poly(lactic acid) surface morphology by solvent-induced crystallization

    Science.gov (United States)

    Gao, Jian; Duan, Lingyan; Yang, Guanghui; Zhang, Qin; Yang, Mingbo; Fu, Qiang

    2012-11-01

    Here, we report some unique crystalline morphologies of poly(lactic acid) (PLA) via organic solvent-induced crystallization. It was revealed that the surface morphology of PLA can be fine tuned by simply varying the volume ratio of a mixed solvent (acetone/ethanol). By increasing the ethanol content in the mixed solvent, we observed a morphological evolution of PLA surface from spherulite to shish-kebab and bamboo-cage-like structure. It was also interesting to find that the initial surface structure of PLA plays an important role to determine the final solvent-induced crystalline morphology. This work provides a new method for manipulating PLA crystal morphology through a simple solvent-induced crystallization.

  12. Effects of aluminium surface morphology and chemical modification on wettability

    DEFF Research Database (Denmark)

    Rahimi, Maral; Fojan, Peter; Gurevich, Leonid

    2014-01-01

    of a monolayer of fluorinated silane, and a combination of those. The effect of these surface modification techniques on roughness and wettability of the aluminium surfaces was elucidated by ellipsometry, contact angle measurements and atomic force microscopy. We demonstrated that by employing different types...... of surface modifications the contact angle of water droplets on aluminium samples can be varied from 12° to more than 120°. A crossover from Cassie–Baxter to Wenzel regime upon changing the surface roughness was also observed....

  13. Nanoscale surface characterization using laser interference microscopy

    Science.gov (United States)

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

    2018-03-01

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

  14. High-surface-area silica nanospheres (KCC-1) with a fibrous morphology

    KAUST Repository

    Polshettiwar, Vivek

    2010-08-02

    Fibrous nanosilica: A new family of high-surface-area silica nanospheres (KCC-1) have been prepared (see picture). KCC-1 features excellent physical properties, including high surface area, unprecedented fibrous surface morphology, high thermal (up to 950 °C) and hydrothermal stabilities, and high mechanical stability. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Ion-beam modifications of the surface morphology and conductivity ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Studies on the surface micromorphology and surface conductivity in thin polymer films of poly vinyl alcohol (PVA) and poly ethylene oxide (PEO) in both as-grown and ion-implanted polymer films have been carried out to reveal certain specific features of the ordered state in these materials. Optical microscopic.

  16. Effect of surface morphology on atmospheric corrosion behaviour of ...

    Indian Academy of Sciences (India)

    Co18Si1B14 ribbon, was evaluated. The wheel side surface of the ribbon was more corroded than the air side surface, due to the higher density of air pockets present. The phases present in atmospheric rust were analysed by X-ray diffraction ...

  17. Ion-beam modifications of the surface morphology and conductivity ...

    Indian Academy of Sciences (India)

    Studies on the surface micromorphology and surface conductivity in thin polymer films of poly vinyl alcohol (PVA) and poly ethylene oxide (PEO) in both as-grown and ion-implanted polymer films have been carried out to reveal certain specific features of the ordered state in these materials. Optical microscopic ...

  18. Morphological characterization of a Daucus L. germplasm collection in Tunisia

    Science.gov (United States)

    The genus Daucus includes about 25 recognized species worldwide. Northern Africa represents a major center of diversity of Daucus, with Tunisia containing at least 12 species and six subspecies. We assessed morphological diversity from a Daucus L. germplasm collection of 103 accessions at the Nation...

  19. Morphological Characterization of Soot from the Atmospheric Combustion of Kerosene

    Directory of Open Access Journals (Sweden)

    Ezekiel Dixon Dikio

    2011-01-01

    Full Text Available Kerosene has been used as a precursor for the production of carbon nanomaterial without a catalyst precursor. Nanomaterials formed in the process have been analysed by Raman, Scanning electron microscope (SEM, x-Ray diffraction (XRD and by Energy dispersive spectroscopy (EDS. Carbon nanomaterial produced show the morphology of carbon nanospheres with diameters of about 0.3 µm.

  20. Time-kill profiles and cell-surface morphological effects of crude ...

    African Journals Online (AJOL)

    MK1201 mycelial extract on the viability and cell surface morphology of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA). Methods: Time-kill assays were conducted by incubating test ...

  1. Three-dimensional morphological analysis of the human sacroiliac joint: influences on the degenerative changes of the auricular surfaces.

    Science.gov (United States)

    Nishi, Keita; Tsurumoto, Toshiyuki; Okamoto, Keishi; Ogami-Takamura, Keiko; Hasegawa, Takashi; Moriuchi, Takefumi; Sakamoto, Junya; Oyamada, Joichi; Higashi, Toshio; Manabe, Yoshitaka; Saiki, Kazunobu

    2018-02-01

    The sacroiliac joint (SIJ) is responsible for weight transmission between the spine and lower extremity. However, details of the structure and function of the SIJ remain unclear. In a previous study, we devised a method of quantitatively evaluating the level of degeneration of the SIJ using an age estimation procedure for the auricular surface of the ilium. Our results in that study suggested that the degree of degeneration of the joint surface may be associated with the morphology of the auricular surface of the ilium. In that study, however, the morphology of the auricular surface of the ilium was simplified for analysis, meaning that more detailed investigations were required in future. In the present study, we focused on individual differences in the shape of SIJ and carried out three-dimensional quantitative evaluation of the morphology of the auricular surface of the ilium to ascertain its association with joint degeneration. We produced three-dimensional images of the right auricular surfaces of the ilium of 100 modern Japanese men (age 19-83), and obtained the three-dimensional rectangular coordinates of 11 defined measurement points. We then calculated 16 parameters indicating the morphological characteristics of the auricular surfaces of the ilium from the three-dimensional rectangular coordinates of these measurement points, and used these to perform principal component analysis to investigate trends in the morphology of the auricular surface of the ilium. We found that the morphology of the auricular surface of the ilium could be characterized in terms of (i) size, (ii) concavity of the posterior border and (iii) amount of undulation. An investigation of the correlation between these parameters and age suggested that the amount of undulation of the auricular surface of the ilium tends to diminish with advancing age. In an investigation of the association between morphology of the auricular surface of the ilium and degeneration of the articular surface

  2. Influence of impurities on the surface morphology of the TIBr crystal semiconductor

    International Nuclear Information System (INIS)

    Santos, Robinson A. dos; Silva, Julio B. Rodrigues da; Martins, Joao F.T.; Ferraz, Caue de M.; Costa, Fabio E. da; Mesquita, Carlos H. de; Hamada, Margarida M.; Gennari, Roseli F.

    2013-01-01

    The impurity effect in the surface morphology quality of TlBr crystals was evaluated, aiming a future application of these crystals as room temperature radiation semiconductor detectors. The crystals were purified and grown by the Repeated Bridgman technique. Systematic measurements were carried out for determining the stoichiometry, structure orientation, surface morphology and impurity of the crystal. A significant difference in the crystals impurity concentration was observed for almost all impurities, compared to those found in the raw material. The crystals wafer grown twice showed a surface roughness and grains which may be due to the presence of impurities on the surface, while those obtained with crystals grown three times presented a more uniform surface: even though, a smaller roughness was still observed. It was demonstrated that the impurities affect strongly the surface morphology quality of crystals. (author)

  3. Effects of acid treatment on the clay palygorskite: XRD, surface area, morphological and chemical composition

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, Katiane Cruz Magalhaes; Santos, Maria do Socorro Ferreira dos; Santos, Maria Rita Morais Chaves; Oliveira, Marilia Evelyn Rodrigues; Osajima, Josy Antevelli; Silva Filho, Edson Cavalcanti da [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil); Carvalho, Maria Wilma Nunes Cordeiro, E-mail: edsonfilho@ufpi.edu.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil)

    2014-08-15

    The palygorskite is an aluminum-magnesium silicate that has a fibrous morphology. Their physicochemical characteristics are the result of high surface area, porosity and thermal resistance which make it an attractive adsorbent. Its adsorption capacity can be increased through chemical reactions and/or heat treatments. The objective of this work is to verify the effects of acid activation on the palygorskite, treated with HCl at 90 °C at concentrations of 2, 4 and 6 mol L{sup -1} in 2 and 4 hours, with clay/acid solution ratio 1 g 10 mL{sup -1} and characterized by techniques: XRF, XRD and surface area. A significant increase in specific surface area was observed in the sample treated with HCl at the concentration 6 mol L{sup -1}. The changes were more pronounced at stricter concentrations of acidity, with decreasing intensity of reflection of the clay indicated in the XRD. These changes were confirmed in the XRF with the leaching of some oxides and with increasing concentration of SiO{sub 2}. (author)

  4. Surfaces wettability and morphology modulation in a fluorene derivative self-assembly system

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Xinhua, E-mail: caoxhchem@163.com; Gao, Aiping; Zhao, Na; Yuan, Fangyuan; Liu, Chenxi; Li, Ruru

    2016-04-15

    Graphical abstract: - Highlights: • The different structures could be obtained in this self-assembly system. • A water-drop could freely roll on the xerogel film with the sliding angle of 15.0. • The superhydrophobic surface can be obtained via supramolecular self-assembly. - Abstract: A new organogelator based on fluorene derivative (gelator 1) was designed and synthesized. Organogels could be obtained via the self-assembly of the derivative in acetone, toluene, ethyl acetate, hexane, DMSO and petroleum ether. The self-assembly process was thoroughly characterized using field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV–vis, FT-IR and the contact angle. Surfaces with different morphologies and wetting properties were formed via the self-assembly of gelator 1 in the six different solvents. Interestingly, a superhydrophobic surface with a contact angle of 150° was obtained from organogel 1 in DMSO and exhibited the lotus-effect. The sliding angle necessary for a water droplet to move on the glass was only 15°. Hydrogen bonding and van der Waals forces were attributed as the main driving forces for gel formation.

  5. Soil surface roughness modeling: limit of global characterization in remote sensing

    Science.gov (United States)

    Chimi-Chiadjeu, O.; Vannier, E.; Dusséaux, R.; Taconet, O.

    2013-10-01

    Many scientists use a global characterization of bare soil surface random roughness. Surface roughness is often characterized by statistical parameters deduced from its autocorrelation function. Assuming an autocorrelation model and a Gaussian height distribution, some authors have developed algorithms for numerical generation of soil surfaces that have the same statistical properties. This approach is widespread and does not take into account morphological aspects of the soil surface micro-topography. Now a detail surface roughness analysis reveals that the micro-topography is structured by holes, aggregates and clods. In the present study, we clearly show that when describing surface roughness as a whole, some information related to morphological aspects is lost. Two Digital Elevation Model (DEM) of a same natural seedbed surface were recorded by stereo photogrammetry. After estimating global parameters of these natural surfaces, we generated numerical surfaces of the same average characteristics by linear filtering. Big aggregates and clods were then captured by a contour-based approach. We show that the two-dimensional autocorrelation functions of generated surfaces and of the two agricultural surfaces are close together. Nevertheless, the number and shape of segmented object contours change from generated surfaces to the natural surfaces. Generated surfaces show fewer and bigger segmented objects than in the natural case. Moreover, the shape of some segmented objects is unrealistic in comparison to real clods, which have to be convex and of low circularity.

  6. Surface roughness and morphology of three nanocomposites after two different polishing treatments by a multitechnique approach.

    Science.gov (United States)

    Janus, J; Fauxpoint, G; Arntz, Y; Pelletier, H; Etienne, O

    2010-05-01

    The purpose of this study was to assess the surface roughness and morphology of three nanocomposites polished with two different polishing systems. Specimens made of hybrid composite (Tetric Ceram [TC] as control) and nanocomposites: nanofilled (Filtek Supreme [FS]), nanofilled hybrid (Grandio [Gr]), complex nanofilled hybrid (Synergy D6 [Syn]) were polished with CompoSystem [CS] or Sof-Lex [SL] polishing discs. The average surface roughness (Ra) before and after polishing was measured using optical profilometry. Both AFM and SEM techniques were additionally used to analyze the surface morphology after polishing with the aim of relating the surface morphology and the surface roughness. Statistical analysis was done by ANOVA using a general linear model (alpha=0.05) with an adjustment for multiple comparisons. Within the same polishing system, FS exhibited the smoothest surface, followed by Syn, TC and Gr (p<0.0001). Sof-Lex polishing discs produced the smoothest surface compared to CompoSystem (p<0.0001). AFM and SEM observations confirmed that the surface roughness was related to the surface morphology and to the average filler size. Positive correlation between the average filler size and the surface roughness suggest that using nanoparticles in the formulation does not necessary improve the surface texture. The nanofilled composite FS, which contains only nanofillers, showed the best results when associated to Sof-Lex polishing discs. 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  7. Morphology Characterization of PP/Clay Nanocomposites Across the Length Scales of the Structural Architecture

    NARCIS (Netherlands)

    Szazdi, Laszlo; Abranyi, Agnes; Pukansky Jr, Bela; Vancso, Gyula J.; Pukanszky, B.; Pukanszky, Bela

    2006-01-01

    The structure and rheological properties of a large number of layered silicate poly(propylene) nanocomposites were studied with widely varying compositions. Morphology characterization at different length scales was achieved by SEM, TEM, and XRD. Rheological measurements supplied additional

  8. Affecting the morphology of silver deposition on carbon nanotube surface: From nanoparticles to dendritic (tree-like) nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Forati-Nezhad, Mohsen [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Mir Mohamad Sadeghi, Gity, E-mail: gsadeghi@aut.ac.ir [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Yaghmaie, Frank [Northern California Nanotechnology Center, University of California, Davis, CA 95616 (United States); Alimohammadi, Farbod [Young Researchers and Elite Club, South Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2015-01-01

    Chemical reduction was used to synthesize silver crystals on the surface of multiwall carbon nanotubes (MWCNTs) in the presence of acetone, N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone, and isopropyl alcohol as solvent. DMF and sodium dodecyl sulfate were used as a reducing and a stabilizing agent, respectively. The structure and nature of hybrid MWCNT/silver were characterized by Raman spectroscopy, FTIR spectroscopy, transmission electron microscopy (TEM), and field emission scanning electron microscope (FESEM). The presence of silver crystals on the nanotubes was confirmed by XRD. The results show the formation of silver crystals on the MWCNT surface and indicate that the morphology of silver crystals can be control by changing the solvent. The type of solvent is an effective parameter that affects the particle size and morphological transition from nanoparticles to silver trees. - Highlights: • The silver crystals are grown on the CNT surface by chemical reduction method. • The morphology of silver crystals is controlled by changing the solvent. • Silver nanoparticles and dendritic nanostructures on CNT surface are achieved. • Any change in structure and surface defects by synthesis condition is investigated.

  9. Stasis and convergence characterize morphological evolution in eupolypod II ferns.

    Science.gov (United States)

    Sundue, Michael A; Rothfels, Carl J

    2014-01-01

    Patterns of morphological evolution at levels above family rank remain underexplored in the ferns. The present study seeks to address this gap through analysis of 79 morphological characters for 81 taxa, including representatives of all ten families of eupolypod II ferns. Recent molecular phylogenetic studies demonstrate that the evolution of the large eupolypod II clade (which includes nearly one-third of extant fern species) features unexpected patterns. The traditional 'athyrioid' ferns are scattered across the phylogeny despite their apparent morphological cohesiveness, and mixed among these seemingly conservative taxa are morphologically dissimilar groups that lack any obvious features uniting them with their relatives. Maximum-likelihood and maximum-parsimony character optimizations are used to determine characters that unite the seemingly disparate groups, and to test whether the polyphyly of the traditional athyrioid ferns is due to evolutionary stasis (symplesiomorphy) or convergent evolution. The major events in eupolypod II character evolution are reviewed, and character and character state concepts are reappraised, as a basis for further inquiries into fern morphology. Characters were scored from the literature, live plants and herbarium specimens, and optimized using maximum-parsimony and maximum-likelihood, onto a highly supported topology derived from maximum-likelihood and Bayesian analysis of molecular data. Phylogenetic signal of characters were tested for using randomization methods and fitdiscrete. The majority of character state changes within the eupolypod II phylogeny occur at the family level or above. Relative branch lengths for the morphological data resemble those from molecular data and fit an ancient rapid radiation model (long branches subtended by very short backbone internodes), with few characters uniting the morphologically disparate clades. The traditional athyrioid ferns were circumscribed based upon a combination of

  10. Morphologic characterization of Butia microspadix Burret (Arecaceae) phitoliths

    OpenAIRE

    Pereira, Janaina Silva Rossi; UTFPR campus Campo Mourão; Parolin, Mauro; FECILCAM; Monteiro, Mayara dos Reis; FECILCAM/UEM; Caxambu, Marcelo Galeazzi; UTFPR; Rasbold, Giliane Géssica; UTFPR

    2013-01-01

    Phytoliths are micrometric bodies of opal, which was deposited between the cells of plant tissues in some species of the Plantae Kingdom. These precipitations are more abundant in the family Poaceae, but it’s significant in other plant families, as Arecaceae, for example. The morphological description of the phytoliths Butia microspadix Burret’s (Butiazinho-do-campo) is important to aid in paleoenvironmental reconstructions of Campos Gerais, Paraná, Brasil. Globular echinate was the predomina...

  11. Nephelium lappaceum L. genetic diversity by morphological and molecular characterization

    OpenAIRE

    De Andrade, Renata Aparecida [UNESP; Wickert, Ester [UNESP; Martins, Antonio Baldo Geraldo [UNESP; De Andrade, Mariana Macedo Costa [UNESP; De Macedo Lemos, Eliana Gertrudes [UNESP

    2011-01-01

    The rambutan (Nephelium lappaceum) is an exotic fruit with great market potential in Brazil. However, there are few available informations about plants with potential for cultivation, because great morphologic variation is observed among plants and for consequence, little uniformity in the orchards and in the fruits. This research had for objective to evaluate the genetic diversity of a collection of rambutan plants obtained by seeds through morfo-chemical analyses of plants and fruits and by...

  12. Metropolitan landscape characterization : A typo-morphological approach

    NARCIS (Netherlands)

    Tisma, A.; Van der Velde, J.R.T.; Nijhuis, S.; Pouderoyen, B.J.J.M.

    2012-01-01

    Dispersed urban regions are characterized by blurred boundaries between urban and rural areas resulting in complex new configurations of urban tissue and landscape space. These new hybrid landscapes challenge existing tools for landscape characterization, which are based on a traditional separation

  13. Morphological characterization of Kielmeyera coriacea Mart. cork from brazilian cerrado

    Directory of Open Access Journals (Sweden)

    Polliana D`Angelo Rios

    2011-09-01

    Full Text Available Kielmeyera coriacea Mart., known as “pau-santo”, is mentioned in the literature as the main tree species which produces cork of the Brazilian Cerrado. The purpose of this study was to describe the morphological aspect of Kielmeyera coriacea (“pau-santo” cork cells through its microscopic structure and to compare it with the cellular morphology of Quercus suber (cork oak, which is the main cork producing species worldwide. The bark from three trees of the species Kielmeyera coriacea Mart. was collected randomly at points 1.30 m above the ground, with four repetitions per sample. Samples came from native stands situated in the region of Luminárias - MG, Brazil. The study of morphological characteristics was conducted by counting the number of sides of the cells, and measuring the dimensions of the cells from images obtained by scanning electron microscopy (SEM. Images were analyzed using the LEOUIF software. The distribution in faces and edges of cork cells from Kielmeyera coriacea, was observed to have from 4 to 8 sides, with a predominance of hexagonal cells, similar to Quercus suber. The averages of height and thickness of the cell walls were 40 to 70 µm and 1.5 to 2.0 µm respectively, indicating cells from an early growth season. Both height and thickness were observed to be greater than those present in Quercus suber

  14. Surface chemistry and morphology in single particle optical imaging

    Science.gov (United States)

    Ekiz-Kanik, Fulya; Sevenler, Derin Deniz; Ünlü, Neşe Lortlar; Chiari, Marcella; Ünlü, M. Selim

    2017-05-01

    Biological nanoparticles such as viruses and exosomes are important biomarkers for a range of medical conditions, from infectious diseases to cancer. Biological sensors that detect whole viruses and exosomes with high specificity, yet without additional labeling, are promising because they reduce the complexity of sample preparation and may improve measurement quality by retaining information about nanoscale physical structure of the bio-nanoparticle (BNP). Towards this end, a variety of BNP biosensor technologies have been developed, several of which are capable of enumerating the precise number of detected viruses or exosomes and analyzing physical properties of each individual particle. Optical imaging techniques are promising candidates among broad range of label-free nanoparticle detectors. These imaging BNP sensors detect the binding of single nanoparticles on a flat surface functionalized with a specific capture molecule or an array of multiplexed capture probes. The functionalization step confers all molecular specificity for the sensor's target but can introduce an unforeseen problem; a rough and inhomogeneous surface coating can be a source of noise, as these sensors detect small local changes in optical refractive index. In this paper, we review several optical technologies for label-free BNP detectors with a focus on imaging systems. We compare the surface-imaging methods including dark-field, surface plasmon resonance imaging and interference reflectance imaging. We discuss the importance of ensuring consistently uniform and smooth surface coatings of capture molecules for these types of biosensors and finally summarize several methods that have been developed towards addressing this challenge.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  16. Effects of hydrogen peroxide bleaching strip gels on dental restorative materials in vitro: surface microhardness and surface morphology.

    Science.gov (United States)

    Duschner, Heinz; Götz, Hermann; White, Donald J; Kozak, Kathleen M; Zoladz, James R

    2004-01-01

    This study examined the effects of peroxide tooth bleaching, including Crest Whitestrips hydrogen peroxide gel treatments, on the surface hardness and morphology of common dental restorative treatments. American Dental Association (ADA) recommended dental restorative materials, including amalgam, dental gold, porcelain, glass ionomer, and composites, were prepared according to manufacturers' instructions. A cycling treatment methodology was employed which alternated ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching treatments included commercial Crest Whitestrips bleaching gels, which utilize hydrogen peroxide as the in situ bleaching source, and several commercial carbamide peroxide bleaching gels. Control treatments included placebo gels and an untreated group. Crest Whitestrips bleaching included treatment exposures simulating recommended clinical exposures (14 hours), along with excess bleaching simulating exposure to five times suggested Crest Whitestrips use. At the conclusion of treatments, surface microhardness measures and surface morphological assessments with standard and variable pressure (VP-) SEMs were conducted to assess the effects of bleaching exposure on the surface morphology and structural integrity of the restoratives. Surface microhardness and SEM measures revealed no significant deleterious effects on the restoration surfaces from Whitestrips gels. These results confirm that tooth bleaching from the selected commercial hydrogen peroxide or carbamide peroxide bleaching systems does not produce changes in surface morphology or microhardness of common dental restorative materials. These results support the clinical safety of the selected commercial bleaching systems to the oral environment, matching results obtained from long-term use of these ingredients applied in dental offices and available in commercial formulations.

  17. Morphological and Optical Characterization of High Density Au/PAA Nanoarrays

    Directory of Open Access Journals (Sweden)

    Mohamed Shaban

    2016-01-01

    Full Text Available Hexagonal nanoarrays of Au nanorods and nanopillar were deposited on nanoporous anodic alumina (PAA membranes utilizing dc electrodeposition. The surface morphologies and optical properties were characterized by using field emission-scanning electron microscopy (FE-SEM and UV-Vis spectrophotometer, respectively. The optical reflectance spectra of the as-prepared, pore widened, and 2D-Au nanorods-coated PAA membranes were studied in detail. The effects of the angle of incident, pore widening time, and electrodeposition time on the characteristic peaks positions and intensities of the fabricated nanoarrays were addressed. As the angle of incident increased, the interference peaks and transverse surface resonance are shifted to longer wavelengths, but the longitudinal surface plasmon resonance is shifted to shorter wavelengths. Also, the reflected intensities are decreased linearly for the as-prepared sample and decreased exponentially for Au/PAA samples. Using the modified Kubelka-Munk radiative transfer model, the energy gap is increased from 2.83 to 3.06 eV and the refractive index is decreased from 1.84 to 1.36 for the as-prepared and 70 min pore widened PAA membranes, respectively. Based on the advantages of the fabrication approach and the enhanced and controlled properties, this generation of Au/PAA arrays can be used as efficient building blocks for nanoelectronics and nanophotonic devices.

  18. Micro and nanostructural characterization of surfaces and interfaces of Portland cement mortars using atomic force microscopy

    International Nuclear Information System (INIS)

    Barreto, M.F.O.; Brandao, P.R.G.

    2014-01-01

    The characterization of Portland cement mortars is very important in the study the interfaces and surfaces that make up the system grout/ceramic block. In this sense, scanning electron microscopy and energy-dispersive (X-ray) spectrometer are important tools in investigating the morphology and chemical aspects. However, more detailed topographic information can be necessary in the characterization process. In this work, the aim was to characterize topographically surfaces and interfaces of mortars applied onto ceramic blocks. This has been accomplished by using the atomic force microscope (AFM) - MFP-3D-SA Asylum Research. To date, the results obtained from this research show that the characterization of cementitious materials with the help of AFM has an important contribution in the investigation and differentiation of hydrated calcium silicates (CSH), calcium hydroxide (Ca(OH)2, ettringite and calcium carbonate by providing morphological and micro topographical data, which are extremely important and reliable for the understanding of cementitious materials. (author)

  19. Morphological and chemical composition characterization of commercial sepia melanin

    CSIR Research Space (South Africa)

    Mbonyiryivuze, A

    2015-06-01

    Full Text Available Melanins are difficult to characterize because of their intractable chemical properties and the heterogeneity in their structural features. Melanin pigments, in fact, are composed of many different types of monomeric units that are connected through...

  20. Effect of surface morphology on atmospheric corrosion behaviour of ...

    Indian Academy of Sciences (India)

    Wintec

    adverse effect of quenched-in defects on the corrosion resistance of Fe34Ni36Cr10P14B6 amorphous alloy has been reported by some investigators (Gravano et al 1992). The inferior corrosion resistance of the wheel side surface has been attributed to higher concentration of quenched- in defects due to higher cooling rate ...

  1. Mechanism of action of pefloxacin on surface morphology, DNA ...

    African Journals Online (AJOL)

    It was observed that the site of pefloxacin action was intracellular and it caused surface alterations. The present investigation also showed the effect of Quinolone pefloxacin on DNA gyrase activity of K. aerogenes. DNA gyrase was purified by affinity chromatography and inhibition of pefloxacin on supercoiling activity of DNA ...

  2. Surface roughness and morphologic changes of zirconia: Effect of ...

    African Journals Online (AJOL)

    10 MPa m1/2), high biocompatibility and natural appearance. ... perpendicularly to the surface at 10 mm distance and was moved in a sweeping fashion by hand during an exposure period of 20 s over the entire area. The energy parameters.

  3. Surface morphology of contact lenses probed with microscopy techniques

    Czech Academy of Sciences Publication Activity Database

    Guryča, Vilém; Hobzová, Radka; Přádný, Martin; Širc, Jakub; Michálek, Jiří

    2007-01-01

    Roč. 30, č. 4 (2007), s. 215-222 ISSN 1367-0484 R&D Projects: GA AV ČR 1QS400500558 Institutional research plan: CEZ:AV0Z40500505 Keywords : atomic force microscopy * scanning electron microscopy * surface roughness Subject RIV: CD - Macromolecular Chemistry

  4. Influence of surface morphology on the immersion mode ice nucleation efficiency of hematite particles

    Energy Technology Data Exchange (ETDEWEB)

    Hiranuma, N.; Hoffmann, N.; Kiselev, A.; Dreyer, A.; Zhang, K.; Kulkarni, G.; Koop, T.; Möhler, O.

    2014-01-01

    In this paper, the effect of the morphological modification of aerosol particles with respect to heterogeneous ice nucleation is comprehensively investigated for laboratory-generated hematite particles as a model substrate for atmospheric dust particles. The surface-area-scaled ice nucleation efficiencies of monodisperse cubic hematite particles and milled hematite particles were measured with a series of expansion cooling experiments using the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud simulation chamber. Complementary offline characterization of physico-chemical properties of both hematite subsets were also carried out with scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, dynamic light scattering (DLS), and an electro-kinetic particle charge detector to further constrain droplet-freezing measurements of hematite particles. Additionally, an empirical parameterization derived from our laboratory measurements was implemented in the single-column version of the Community Atmospheric Model version 5 (CAM5) to investigate the model sensitivity in simulated ice crystal number concentration on different ice nucleation efficiencies. From an experimental perspective, our results show that the immersion mode ice nucleation efficiency of milled hematite particles is almost an order of magnitude higher at -35.2 °C < T < -33.5 °C than that of the cubic hematite particles, indicating a substantial effect of morphological irregularities on immersion mode freezing. Our modeling results similarly show that the increased droplet-freezing rates of milled hematite particles lead to about one order magnitude higher ice crystal number in the upper troposphere than cubic hematite particles. Finally and overall, our results suggest that the surface irregularities and associated active sites lead to greater ice activation through droplet freezing.

  5. Synthesis and characterization of different morphological SnS nanomaterials

    International Nuclear Information System (INIS)

    Chaki, Sunil H; Chaudhary, Mahesh D; Deshpande, M P

    2014-01-01

    SnS in three nano forms possessing different morphologies such as particles, whiskers and ribbons were synthesised by chemical route. The morphology variation was brought about in the chemical route synthesis by varying a synthesis parameter such as temperature and influencing the synthesis by use of surfactant. The elemental composition determination by energy dispersive analysis of x-rays (EDAX) showed that all three synthesized SnS nanomaterials were tin deficient. The x-ray diffraction (XRD) study of the three SnS nanomaterials showed that all of them possess orthorhombic structure. The Raman spectra of the three SnS nanomaterials showed that all three samples possess three common distinguishable peaks. In them two peaks lying at 98 ± 1 cm −1 and 224 ± 4 cm −1 are the characteristic A g mode of SnS. The third peak lying at 302 ± 1 cm −1 is associated with secondary Sn 2 S 3 phase. The transmission electron microscopy (TEM) confirmed the respective morphologies. The optical analysis showed that they possess direct as well as indirect optical bandgap. The electrical transport properties study on the pellets prepared from the different nanomaterials of SnS showed them to be semiconducting and p-type in nature. The current–voltage (I–V) plots of the silver (Ag)/SnS nanomaterials pellets for dark and incandescent illumination showed that all configurations showed good ohmic behaviour except Ag/SnS nanoribbons pellet configuration under illumination. All the obtained results are discussed in detail. (paper)

  6. Morphological characterization of nanofibers: methods and application in practice

    Czech Academy of Sciences Publication Activity Database

    Širc, Jakub; Hobzová, Radka; Kostina, Nina Yu.; Munzarová, M.; Juklíčková, M.; Lhotka, M.; Kubinová, Šárka; Zajícová, Alena; Michálek, Jiří

    2012-01-01

    Roč. 2012, č. 2012 (2012), 327369_1-327369_14 ISSN 1687-4110 R&D Projects: GA AV ČR KAN200520804; GA ČR GA304/07/1129; GA MŠk EE2.3.30.0029 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50390512; CEZ:AV0Z50520514 Institutional support: RVO:61389013 ; RVO:68378041 ; RVO:68378050 Keywords : nanofibers * electrospinning * morphology Subject RIV: CD - Macromolecular Chemistry; FH - Neurology (UEM-P); EI - Biotechnology ; Bionics (UMG-J) Impact factor: 1.547, year: 2012

  7. The effects of processing conditions on the surface morphology and hydrophobicity of polyvinylidene fluoride membranes prepared via vapor-induced phase separation

    Science.gov (United States)

    Peng, Yuelian; Fan, Hongwei; Ge, Ju; Wang, Shaobin; Chen, Ping; Jiang, Qi

    2012-12-01

    The present investigation reveals how the surface morphology and the hydrophobicity of polyvinylidene fluoride (PVDF) membranes, which were prepared via a vapor-induced phase separation method, were affected by the initial PVDF content in the casting solution and the air temperature. The surface morphology was characterized with scanning electron microscopy. A ternary phase diagram of PVDF/N, N-dimethylacetamide/water was constructed to explain the formation mechanism of the different morphologies. The results show that different membrane morphologies and hydrophobicities can be obtained by changing the processing conditions. Low air temperature and high PVDF contents facilitate the crystallization process, resulting in the formation of a porous skin and particle morphology, which increases the hydrophobicity of the surface. High air temperature and low PVDF contents are favorable for the formation of a net-like surface morphology via spinodal decomposition and lead to a superhydrophobic surface. Theoretical calculations were performed to testify that the net-like surface was more favorable for superhydrophobicity than the particle-based surface.

  8. Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages.

    Science.gov (United States)

    Wang, H; Chen, D; Yuan, G; Ma, X; Dai, X

    2013-02-01

    In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low

  9. Examination of High Resolution Channel Topography to Determine Suitable Metrics to Characterize Morphological Complexity

    Science.gov (United States)

    Stewart, R. L.; Gaeuman, D.

    2015-12-01

    Complex bed morphology is deemed necessary to restore salmonid habitats, yet quantifiable metrics that capture channel complexity have remained elusive. This work utilizes high resolution topographic data from the 40 miles of the Trinity River of northern California to determine a suitable metric for characterizing morphological complexity at the reach scale. The study area is segregated into reaches defined by individual riffle pool units or aggregates of several consecutive units. Potential measures of complexity include rugosity and depth statistics such as standard deviation and interquartile range, yet previous research has shown these metrics are scale dependent and subject to sampling density-based bias. The effect of sampling density on the present analysis has been reduced by underrepresenting the high resolution topographic data as a 3'x 3' raster so that all areas are equally sampled. Standard rugosity, defined as the three-dimensional surface area divided by projected area, has been shown to be dependent on average depth. We therefore define R*, a empirically depth-corrected rugosity metric in which rugosity is corrected using an empirical relationship based on linear regression between the standard rugosity metric and average depth. By removing the dependence on depth using a regression based on the study reach, R* provides a measure reach scale complexity relative to the entire study area. The interquartile range of depths is also depth-dependent, so we defined a non-dimensional metric (IQR*) as the interquartile range dividing by median depth. These are calculated to develop rankings of channel complexity which, are found to closely agree with perceived channel complexity observed in the field. Current efforts combine these measures of morphological complexity with salmonid habitat suitability to evaluate the effects of channel complexity on the various life stages of salmonids. Future work will investigate the downstream sequencing of channel

  10. Morphological and molecular characterization of Paragonimus westermani in northeastern India.

    Science.gov (United States)

    Devi, K Rekha; Narain, Kanwar; Agatsuma, Takeshi; Blair, David; Nagataki, Mitsuru; Wickramasinghe, S; Yatawara, L; Mahanta, Jagadish

    2010-10-01

    Evidence for the presence of lung flukes of the Paragonimus westermani in India remains scant. In particular, evidence based on morphology of adult worms is lacking. Metacercariae of the genus Paragonimus, recovered from crabs in two regions of northeastern India, were raised to adulthood in laboratory rats. Morphologically, these worms appear to be P. westermani. DNA sequences from the second internal transcribed spacer (ITS2) and a portion of the ribosomal large subunit gene (28S) of the nuclear ribosomal RNA gene repeat, as well as fragments of the mitochondrial cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes, all supported this identification. Molecular phylogenetic methods were used for studying the relatedness of these Indian flukes with counterparts from southeast and far-east Asia. Molecular data showed that Indian representatives of the P. westermani complex represent a distinct lineage. It is unclear whether the Indian form can cause disease in humans as some members of the complex do elsewhere. Copyright 2010 Elsevier B.V. All rights reserved.

  11. Characterization of Morphological Diversity of Jute Mallow (Corchorus spp.

    Directory of Open Access Journals (Sweden)

    Munguatosha Ngomuo

    2017-01-01

    Full Text Available Jute mallow is a traditional leaf vegetable that is an important part of daily diet for the majority of people in rural areas in sub-Saharan Africa. Here we employed quantitative and qualitative phenotypic traits to assess the morphological diversity of 90 accessions using univariate and multivariate analyses. Field experiments were conducted for two seasons to identify accessions suitable for leaf yield. The accessions were significantly variable in all traits. Highest variability among accessions was found in harvest index, biomass yield, and weight of 1000 seeds. The traits that significantly correlated with biomass yield include plant height (r=0.448, petiole length (r=0.237, primary branches (r=0.319, and number of leaves per plant (r=0.333. Principal component analysis showed that the first five PCs with eigenvalues ≥1 explained 72.9% of the total variability in the accessions. Pods per plant, primary branches, secondary branches, and number of leaves per plant accounted for highest variability in PC1. Cluster analysis grouped the accessions into five major clusters mainly based on their origin. Thus, the collection displayed high variation in morphological traits, particularly those related to leaf yield. These accessions are therefore useful in breeding for the improvement of the crop and germplasm management.

  12. Antifreeze Glycoproteins Alter the Molecular Scale Surface Morphology of Ice

    Science.gov (United States)

    Zepeda, Salvador; Orme, Christine A.; Qiu, Roger; Yeh, Yin

    2003-03-01

    Trematomas borchgrevinki live in the harsh super-cooled waters of the Antarctic. Critical to their survival are antifreeze glycoproteins (AFGPs) that further suppress the freezing temperature of their blood serum in addition to the colligative action of salts found in the ocean. These proteins also modify ice crystal growth habits as well as inhibit recrystallization in polycrystalline ice. To date many other types of antifreeze proteins have been identified in cold weather insects, plants, and other fish, but the exact mechanism is not entirely understood. The mechanism is non-colligative since only a few mg/ml are required for ice crystal growth inhibition and a non-equilibrium melting/freezing point hysteresis is observed. Atomic force microscopy (AFM) can yield a wealth of surface information that can reveal molecular scale information of biomineralization processes. We use AFM to directly probe the surface of ice crystals grown from the vapor in the pure phase and in the presence of growth inhibitors/modifiers, AFGPs. Results show that the AFGPs heavily pin the surface of ice.

  13. Structural and morphological TEM characterization of GaAs based nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Soda, Marcello

    2012-02-03

    The question of a structural and morphological characterization of GaAs based nanowires is the research interest of this thesis. For this purpose standard and analytical transmission electron microscopy techniques were employed. New investigation methodologies are introduced in order to obtain a reliable interpretation of the results. The principal motivation on developing a new investigation method is the necessity to relate the results of crystal structure and morphology characterizations to microscopic and NW-specific parameters and not to macroscopic and general growth parameters. This allows a reliable comparison of NW characteristics and enhances the comprehension of their growth mechanism.The analysis of the results on crystal structure investigations, assuming this new perspective, delivers the fundamental finding that the axial growth of Au-assisted GaAs NWs can change in a pseudo Ga-assisted growth due to a non steady-state regime of the Ga accumulation process in the liquid droplet. The attempt to associate the observed crystal structures to one of these two growth modes reveals that zinc blende segments are most probably generated when a pseudo Ga-assisted growth occurs. This experimental evidence is in accordance with investigations developed by Glas et al. and Spirkoska et al. and with the current understanding of the NW growth mechanism and unifies the interpretation of catalytic growth of GaAs NWs. A Mn doped GaAs shell deposited at low temperature on core GaAs NWs is characterized for the first time. The growth is found to be epitaxial and to confer the quality of the core crystal to the shell crystal. As a consequence a high stacking fault density of the core NW limits the temperature of the shell growth due to the formation of clusters. Cross sections of (Ga,Mn)As shells are investigated. Simple kinetic and thermodynamical considerations lead to the conclusion of morphological instability of the low temperature radial growth. Analytical

  14. Simultaneous formation of multiscale hierarchical surface morphologies through sequential wrinkling and folding

    Science.gov (United States)

    Wang, Yu; Sun, Qingyang; Xiao, Jianliang

    2018-02-01

    Highly organized hierarchical surface morphologies possess various intriguing properties that could find important potential applications. In this paper, we demonstrate a facile approach to simultaneously form multiscale hierarchical surface morphologies through sequential wrinkling. This method combines surface wrinkling induced by thermal expansion and mechanical strain on a three-layer structure composed of an aluminum film, a hard Polydimethylsiloxane (PDMS) film, and a soft PDMS substrate. Deposition of the aluminum film on hard PDMS induces biaxial wrinkling due to thermal expansion mismatch, and recovering the prestrain in the soft PDMS substrate leads to wrinkling of the hard PDMS film. In total, three orders of wrinkling patterns form in this process, with wavelength and amplitude spanning 3 orders of magnitude in length scale. By increasing the prestrain in the soft PDMS substrate, a hierarchical wrinkling-folding structure was also obtained. This approach can be easily extended to other thin films for fabrication of multiscale hierarchical surface morphologies with potential applications in different areas.

  15. Morphological and textural characterization of functionalized particulate silica xerogels

    Science.gov (United States)

    de Miranda, Lazaro A.; Mohallem, Nelcy D. S.; de Magalhães, Welington F.

    2006-03-01

    The functionalization of xerogels for use in chromatography and catalysis was carried out by solubilization of amorphous silica using a soxhlet extractor. Xerogels were prepared by sol-gel method using tetraethoxysilane, TEOS, ethanol, and water in a 1/3/10 molar ratio with HCl and HF as catalysts. The samples were prepared in monolithic form and dried at 70 °C and 550 °C for 1 h each. After functionalization, changes in textural and morphological characteristics of xerogels were investigated by means of nitrogen gas adsorption, positron annihilation lifetime spectroscopy (PALS), and scanning electron microscopy (SEM). As the analysis methods are based on different physical principles, the results are complementary, leading to a good knowledge of the texture of the samples studied.

  16. Morphological and ultrastructural characterization of sea urchin immune cells.

    Science.gov (United States)

    Deveci, Remziye; Şener, Ecem; İzzetoğlu, Savaş

    2015-05-01

    The free circulating coelomocytes in the coelomic cavity of echinoderms are considered to be immune effectors by phagocytosis, encapsulation, cytotoxicity, and by the production of antimicrobial agents. Although echinoderms (especially sea urchin embryo) have been used as a model organisms in biology, no uniform criteria exist for classification of coelomocytes in echinoderms, and few studies have reported about the biological functions of their coelomocytes. Hence, we study the coelomocytes in the echinoid sea urchin, Paracentrotus lividus, and describe their morphological and ultrastructural features using light and transmission electron microscopes. We classify the coelomocytes of P. lividus into red spherule and colorless spherule cells, small cells, vibratile cells, and phagocytic cells; petaloid and filopodial cells. To our knowledge, this is the first report describing ultrastructural details of the coelomocytes of P. lividus. © 2015 Wiley Periodicals, Inc.

  17. Morphological and molecular characterization of selected Ramaria mycorrhizae.

    Science.gov (United States)

    Nouhra, Eduardo R; Horton, Thomas R; Cazares, Efren; Castellano, Michael

    2005-01-01

    Ramaria species are conspicuous mycorrhizal symbionts of conifers in the Pacific Northwest. Here we collected and identified sporocarps and associated ectomycorrhizae of Ramaria acrisiccescens Marr & Stuntz, R. cyaneigranosa Marr & Stuntz, R. sandaracina Marr & Stuntz, R. celerivirescens Marr & Stuntz, and R. flavobrunnescens var. aromatica Marr & Stuntz. An internal transcribed spacer (ITS)- restriction fragment length polymorphism pattern was observed for each of the Ramaria species and used as a diagnostic tool to support the identification of mycorrhizae occurring in mats below the sporocarps. We provide a description of ectomycorrhizae of Ramaria, which exhibit similar macro- and microscopic characteristics such as ramification pattern, coloration, abundance of mycelial strands and emanating hyphae, mantle morphology and chemical reactions of mantle and mycelial strands with KOH, FeSO4 and Melzer's reagent. Sequences of the ITS region for each of the species are deposited in the GenBank.

  18. Effect of Shot Peening in Different Shot Distance and Shot Angle on Surface Morphology, Surface Roughness and Surface Hardness of 316L Biomaterial

    Science.gov (United States)

    Umbu Kondi Maliwemu, Erich; Malau, Viktor; Iswanto, Priyo Tri

    2018-01-01

    Shot peening is a mechanical surface treatment with a beneficial effect to generate compressive residual stress caused by plastic deformation on the surface of material. This plastic deformation can improve the surface characteristics of metallic materials, such as modification of surface morphology, surface roughness, and surface hardness. The objective of this study is to investigate the effect of shot peening in different shot distance and shot angle on surface morphology, surface roughness, and surface hardness of 316L biomaterial. Shot distance was varied at 6, 8, 10, and 12 cm and shot angle at 30, 60, and 90°, working pressure at 7 kg/cm2, shot duration for 20 minutes, and using steel balls S-170 with diameter of 0.6 mm. The results present that the shot distance and shot angle of shot peening give the significant effect to improve the surface morphology, surface roughness, and surface hardness of 316 L biomaterial. Shot peening can increase the surface roughness by the increasing of shot distance and by the decreasing of shot angle. The nearest shot distance (6 cm) and the largest shot angle (90°) give the best results on the grain refinement with the surface roughness of 1.04 μm and surface hardness of 534 kg/mm2.

  19. Characterization structural and morphology ZSM-5 zeolite by hydrothermal synthesis

    International Nuclear Information System (INIS)

    Silva, V.J.; Crispim, A.C.; Queiroz, M.B.; Laborde, H.M.; Rodrigues, M.G.F.; Menezes, R.R.

    2009-01-01

    Solid acids are catalytic materials commonly used in the chemical industry. Among these zeolites are the most important business processes including water treatment, gas separation, and cracking long hydrocarbon chains to produce high octane gasoline. Its synthesis, characterization and applications have been widely studied. The objective this study was to synthesize the ZSM-5 zeolite for future use in separation processes and catalysis. The zeolite ZSM-5 was prepared by hydrothermal synthesis at 170°C, using silica, deionized water and the director of structures (TPABr - tetrapropylammonium bromide). The materials were characterized by X ray diffraction (XRD), scanning electron microscopy (SEM) and semiquantitative chemical analysis by X ray fluorescence (XRF). According to the XRD was possible to observe the formation of ZSM-5 zeolite, with peaks intense and well defined. The SEM showed the formation of individual particles, clean, rounded shapes. (author)

  20. Different methods to alter surface morphology of high aspect ratio structures

    Energy Technology Data Exchange (ETDEWEB)

    Leber, M., E-mail: moritz.leber@utah.edu [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT (United States); Shandhi, M.M.H. [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT (United States); Hogan, A. [Blackrock Microsystems, Salt Lake City, UT (United States); Solzbacher, F. [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT (United States); Bhandari, R.; Negi, S. [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT (United States); Blackrock Microsystems, Salt Lake City, UT (United States)

    2016-03-01

    Graphical abstract: Surface engineering of high aspect ratio silicon structures. - Highlights: • Multiple roughening techniques for high aspect ratio devices were investigated. • Modification of surface morphology of high aspect ratio silicon devices (1:15). • Decrease of 76% in impedance proves significant increase in surface area. - Abstract: In various applications such as neural prostheses or solar cells, there is a need to alter the surface morphology of high aspect ratio structures so that the real surface area is greater than geometrical area. The change in surface morphology enhances the devices functionality. One of the applications of altering the surface morphology is of neural implants such as the Utah electrode array (UEA) that communicate with single neurons by charge injection induced stimulation or by recording electrical neural signals. For high selectivity between single cells of the nervous system, the electrode surface area is required to be as small as possible, while the impedance is required to be as low as possible for good signal to noise ratios (SNR) during neural recording. For stimulation, high charge injection and charge transfer capacities of the electrodes are required, which increase with the electrode surface. Traditionally, researchers have worked with either increasing the roughness of the existing metallization (platinum grey, black) or other materials such as Iridium Oxide and PEDOT. All of these previously investigated methods lead to more complicated metal deposition processes that are difficult to control and often have a critical impact on the mechanical properties of the metal films. Therefore, a modification of the surface underneath the electrode's coating will increase its surface area while maintaining the standard and well controlled metal deposition process. In this work, the surfaces of the silicon micro-needles were engineered by creating a defined microstructure on the electrodes surface using several

  1. Modeling the Excess Cell Surface Stored in a Complex Morphology of Bleb-Like Protrusions.

    Directory of Open Access Journals (Sweden)

    Maryna Kapustina

    2016-03-01

    Full Text Available Cells transition from spread to rounded morphologies in diverse physiological contexts including mitosis and mesenchymal-to-amoeboid transitions. When these drastic shape changes occur rapidly, cell volume and surface area are approximately conserved. Consequently, the rounded cells are suddenly presented with a several-fold excess of cell surface whose area far exceeds that of a smooth sphere enclosing the cell volume. This excess is stored in a population of bleb-like protrusions (BLiPs, whose size distribution is shown by electron micrographs to be skewed. We introduce three complementary models of rounded cell morphologies with a prescribed excess surface area. A 2D Hamiltonian model provides a mechanistic description of how discrete attachment points between the cell surface and cortex together with surface bending energy can generate a morphology that satisfies a prescribed excess area and BLiP number density. A 3D random seed-and-growth model simulates efficient packing of BLiPs over a primary rounded shape, demonstrating a pathway for skewed BLiP size distributions that recapitulate 3D morphologies. Finally, a phase field model (2D and 3D posits energy-based constitutive laws for the cell membrane, nematic F-actin cortex, interior cytosol, and external aqueous medium. The cell surface is equipped with a spontaneous curvature function, a proxy for the cell surface-cortex couple, that is a priori unknown, which the model "learns" from the thin section transmission electron micrograph image (2D or the "seed and growth" model image (3D. Converged phase field simulations predict self-consistent amplitudes and spatial localization of pressure and stress throughout the cell for any posited stationary morphology target and cell compartment constitutive properties. The models form a general framework for future studies of cell morphological dynamics in a variety of biological contexts.

  2. Morphological and molecular characterization of fungal pathogen, Magnaphorthe oryzae

    Science.gov (United States)

    Hasan, Nor'Aishah; Rafii, Mohd Y.; Rahim, Harun A.; Ali, Nusaibah Syd; Mazlan, Norida; Abdullah, Shamsiah

    2016-02-01

    Rice is arguably the most crucial food crops supplying quarter of calories intake. Fungal pathogen, Magnaphorthe oryzae promotes blast disease unconditionally to gramineous host including rice species. This disease spurred an outbreaks and constant threat to cereal production. Global rice yield declining almost 10-30% including Malaysia. As Magnaphorthe oryzae and its host is model in disease plant study, the rice blast pathosystem has been the subject of intense interest to overcome the importance of the disease to world agriculture. Therefore, in this study, our prime objective was to isolate samples of Magnaphorthe oryzae from diseased leaf obtained from MARDI Seberang Perai, Penang, Malaysia. Molecular identification was performed by sequences analysis from internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes. Phylogenetic affiliation of the isolated samples were analyzed by comparing the ITS sequences with those deposited in the GenBank database. The sequence of the isolate demonstrated at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaphorthe oryzae. Morphological observed under microscope demonstrated that the structure of conidia followed similar characteristic as M. oryzae. Finding in this study provide useful information for breeding programs, epidemiology studies and improved disease management.

  3. Morphological and molecular characterization of fungal pathogen, Magnaphorthe oryzae

    International Nuclear Information System (INIS)

    Hasan, Nor’Aishah; Rafii, Mohd Y.; Rahim, Harun A.; Ali, Nusaibah Syd; Mazlan, Norida; Abdullah, Shamsiah

    2016-01-01

    Rice is arguably the most crucial food crops supplying quarter of calories intake. Fungal pathogen, Magnaphorthe oryzae promotes blast disease unconditionally to gramineous host including rice species. This disease spurred an outbreaks and constant threat to cereal production. Global rice yield declining almost 10-30% including Malaysia. As Magnaphorthe oryzae and its host is model in disease plant study, the rice blast pathosystem has been the subject of intense interest to overcome the importance of the disease to world agriculture. Therefore, in this study, our prime objective was to isolate samples of Magnaphorthe oryzae from diseased leaf obtained from MARDI Seberang Perai, Penang, Malaysia. Molecular identification was performed by sequences analysis from internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes. Phylogenetic affiliation of the isolated samples were analyzed by comparing the ITS sequences with those deposited in the GenBank database. The sequence of the isolate demonstrated at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaphorthe oryzae. Morphological observed under microscope demonstrated that the structure of conidia followed similar characteristic as M. oryzae. Finding in this study provide useful information for breeding programs, epidemiology studies and improved disease management

  4. Effect of droplet morphology on growth dynamics and heat transfer during condensation on superhydrophobic nanostructured surfaces.

    Science.gov (United States)

    Miljkovic, Nenad; Enright, Ryan; Wang, Evelyn N

    2012-02-28

    Condensation on superhydrophobic nanostructured surfaces offers new opportunities for enhanced energy conversion, efficient water harvesting, and high performance thermal management. These surfaces are designed to be Cassie stable and favor the formation of suspended droplets on top of the nanostructures as compared to partially wetting droplets which locally wet the base of the nanostructures. These suspended droplets promise minimal contact line pinning and promote passive droplet shedding at sizes smaller than the characteristic capillary length. However, the gas films underneath such droplets may significantly hinder the overall heat and mass transfer performance. We investigated droplet growth dynamics on superhydrophobic nanostructured surfaces to elucidate the importance of droplet morphology on heat and mass transfer. By taking advantage of well-controlled functionalized silicon nanopillars, we observed the growth and shedding behavior of suspended and partially wetting droplets on the same surface during condensation. Environmental scanning electron microscopy was used to demonstrate that initial droplet growth rates of partially wetting droplets were 6× larger than that of suspended droplets. We subsequently developed a droplet growth model to explain the experimental results and showed that partially wetting droplets had 4-6× higher heat transfer rates than that of suspended droplets. On the basis of these findings, the overall performance enhancement created by surface nanostructuring was examined in comparison to a flat hydrophobic surface. We showed these nanostructured surfaces had 56% heat flux enhancement for partially wetting droplet morphologies and 71% heat flux degradation for suspended morphologies in comparison to flat hydrophobic surfaces. This study provides insights into the previously unidentified role of droplet wetting morphology on growth rate, as well as the need to design Cassie stable nanostructured surfaces with tailored droplet

  5. Morphology of ablation craters generated by ultra-short laser pulses in dentin surfaces: AFM and ESEM evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Daskalova, A., E-mail: a_daskalova@code.bg [Institute of Electronics, Bulgarian Academy of Sciences, 72, Tsarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Bashir, S.; Husinsky, W. [IAP, Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Vienna (Austria)

    2010-11-15

    In this study, the surface morphology and structure of dentin after ablation by ultra-short pulses were evaluated using environmental scanning electron microscopy (ESEM) and atomic force microscopy (AFM). The dentin specimens examined were irradiated by a chirped-pulse-amplification (CPA) Ti:sapphire laser (800 nm) and the optimal conditions for producing various nanostructures were determined. Based on the ESEM results, it was possible to identify an energy density range as the ablation threshold for dentin. The laser-induced damage was characterized over the fluence range 1.3-2.1 J/cm{sup 2}. The results demonstrate that by selecting suitable parameters one can obtain efficient dentin surface preparation without evidence of thermal damage, i.e., with minimized heat affected zones and reduced collateral damage, the latter being normally characterized by formation of microcracks, grain growth and recrystallization in the heat affected zones.

  6. Optical Properties and Surface Morphology of Nano-composite PMMA: TiO2 Thin Films

    International Nuclear Information System (INIS)

    Lyly Nyl Ismail; Ahmad Fairoz Aziz; Habibah Zulkefle

    2011-01-01

    There are two nano-composite PMMA: TiO 2 solutions were prepared in this research. First solution is nano-composite PMMA commercially available TiO 2 nanopowder and the second solution is nano-composite PMMA with self-prepared TiO 2 powder. The self-prepared TiO 2 powder is obtained by preparing the TiO 2 sol-gel. Solvo thermal method were used to dry the TiO 2 sol-gel and obtained TiO 2 crystal. Ball millers were used to grind the TiO 2 crystal in order to obtained nano sized powder. Triton-X was used as surfactant to stabilizer the composite between PMMA: TiO 2 . Besides comparing the nano-composite solution, we also studied the effect of the thin films thickness on the optical properties and surface morphology of the thin films. The thin films were deposited by sol-gel spin coating method on glass substrates. The optical properties and surface characterization were measured with UV-VIS spectrometer equipment and atomic force microscopy (AFM). The result showed that nano-composite PMMA with self prepared TiO 2 give high optical transparency than nano-composite PMMA with commercially available TiO 2 nano powder. The results also indicate as the thickness is increased the optical transparency are decreased. Both AFM images showed that the agglomerations of TiO 2 particles are occurred on the thin films and the surface roughness is increased when the thickness is increased. High agglomeration particles exist in the AFM images for nano-composite PMMA: TiO 2 with TiO 2 nano powder compare to the other nano-composite solution. (author)

  7. Characterization of phosphate films on aluminum surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, B.; Ramamurthy, S.; McIntyre, N.S. [Univ. of Western Ontario, London, Ontario (Canada)

    1997-08-01

    A thin layer of phosphate conversion coating was formed on pure aluminum in a commercial zinc-manganese phosphating bath. A number of surface analytical techniques were used to characterize the phosphate thin films formed after immersion times ranging from 30 s to 10 min. The coating contained mainly a crystalline structure with dispersed micrometer-scale cavities. The major constituents of the phosphate film were zinc, phosphorus, and oxygen; a small amount of manganese was also detected. Based on these results, a three-stage mechanism was proposed for the formation and the growth of phosphate conversion coatings on aluminum. Electrochemical impedance spectroscopy was used to evaluate the corrosion performance of phosphated and uncoated aluminum samples in 0.50 M Na{sub 2}SO{sub 4} and 0.10 M H{sub 2}SO{sub 4} solutions. Both types of samples exhibited a passive state in the neutral solution and general corrosion behavior in the acid solution.

  8. The Morphology, Dynamics and Potential Hotspots of Land Surface Temperature at a Local Scale in Urban Areas

    Directory of Open Access Journals (Sweden)

    Jiong Wang

    2015-12-01

    Full Text Available Current characterization of the Urban Heat Island (UHI remains insufficient to support the effective mitigation and adaptation of increasing temperatures in urban areas. Planning and design strategies are restricted to the investigation of temperature anomalies at a city scale. By focusing on Land Surface Temperature of Wuhan, China, this research examines the temperature variations locally where mitigation and adaptation would be more feasible. It shows how local temperature anomalies can be identified morphologically. Technically, the MODerate-resolution Imaging Spectroradiometer satellite image products are used. They are first considered as noisy observations of the latent temperature patterns. The continuous latent patterns of the temperature are then recovered from these discrete observations by using the non-parametric Multi-Task Gaussian Process Modeling. The Multi-Scale Shape Index is then applied in the area of focus to extract the local morphological features. A triplet of shape, curvedness and temperature is formed as the criteria to extract local heat islands. The behavior of the local heat islands can thus be quantified morphologically. The places with critical deformations are identified as hotpots. The hotspots with certain yearly behavior are further associated with land surface composition to determine effective mitigation and adaptation strategies. This research can assist in the temperature and planning field on two levels: (1 the local land surface temperature patterns are characterized by decomposing the variations into fundamental deformation modes to allow a process-based understanding of the dynamics; and (2 the characterization at local scale conforms to planning and design conventions where mitigation and adaptation strategies are supposed to be more practical. The weaknesses and limitations of the study are addressed in the closing section.

  9. Characterization of nanoparticle formation and aggregation on mineral surfaces

    International Nuclear Information System (INIS)

    Glenn Waychunas; Young-Shin Jun

    2007-01-01

    The research effort in the Waychunas group is focused on the characterization and measurement of processes at the mineral-water interfaces specifically related to the onset of precipitation. This effort maps into one of the main project groups with the Penn State University EMSI (CEKA) known as PIG (Precipitation Interest Group), and involves collaborations with several members of that group. Both synchrotron experimentation and technique development are objectives, with the goals of allowing precipitation from single molecule attachment to sub-monolayer coverage to be detected and analyzed. The problem being addressed is the change in reactivity of mineral interfaces due to passivation or activation by precipitates or sorbates. In the case of passivation, fewer active sites may be involved in reactions with environmental fluids, while in the activated case the precipitate may be much more reactive than the substrate, or result in the creation of a higher density of active sites. We approach this problem by making direct measurements of several types of precipitation reactions: iron-aluminum oxide formation on quartz and other substrates from both homogeneous (in solution) nucleation, and heterogeneous (on the surface) nucleation; precipitation and sorption of silicate monomers and polymers on Fe oxide surfaces; and development of grazing-incidence small angle x-ray scattering (GISAXS) as a tool for in-situ measurement of precipitate growth, morphology and aggregation. We expect that these projects will produce new fundamental information on reactive interface growth, passivation and activation, and be applicable to a wide range of environmental interfaces

  10. Synthesis, Characterization (Molecular-Morphological) and Theoretical Morphology Predictions of Poly(cyclohexadiene) Containing Linear Triblock Terpolymers

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajeev [ORNL; Dadmun, Mark D [ORNL; Sumpter, Bobby G [ORNL; Mays, Jimmy [ORNL; Avgeropoulos, Apostolos [University of Athens, Athens, Greece; Zafeiropoulos, N.E. [University of Athens, Athens, Greece; Misichoronis, K. [University of Athens, Athens, Greece; Rangou, S. [University of Athens, Athens, Greece; Ashcraft, E. [University of Tennessee, Knoxville (UTK)

    2013-01-01

    The synthesis via anionic polymerization of six linear triblock terpolymers with various sequences of blocks such as PS (polystyrene), PB (polybutadiene), PI (polyisoprene) and PCHD (poly(1,3-cyclohexadiene)) is reported. The synthesis of the terpolymers was accomplished by the use of anionic polymerization with high vacuum techniques and sequential monomer addition. Molecular characterization of the samples was performed via size exclusion chromatography and membrane osmometry to measure polydispersity indices and the number-average molecular weights, respectively. Proton nuclear magnetic resonance spectroscopy was adopted to verify the type of microstructure for the polydienes as well as to calculate the molar composition. Structural characterization was performed via transmission electron microscopy and small angle X-ray scattering and several morphologies were observed including one which has not been reported previously. Real-space self-consistent field theory (SCFT) without a priori knowledge about the symmetry of the periodic structures was used to elucidate the thermodynamics of the synthesized triblock copolymers.

  11. Morphological observation and characterization of thePseudoregma bambucicolawith the scanning electron microscope.

    Science.gov (United States)

    Nong, Xiang; Zeng, Xuemei; Yang, Yaojun; Liang, Zi; Tang, Mei; Liao, Lejuan; Luo, Chaobing

    2017-11-01

    Both leica microscopic camera system and scanning electron microscopy was used to observe and characterize the feet, back, abdomen, antennae and mouthparts of the Pseudoregma bambucicola from the bamboo, Bambusa multiplex . The possible functions of all the external morphological characteristics of the P. bambucicola were described and discussed in detail, which offers a basis for further enriching the biology, phylogeny and ecological niche of the P. bambucicola . Moreover, the morphological results should contribute to morphological identification and differentiation of the P. bambucicola from other aphids in the same family.

  12. Morphological characterization of the reproductive system of irradiated Anastrepha fraterculus

    Energy Technology Data Exchange (ETDEWEB)

    Bartolucci, Andrea, E-mail: andreabartolucci@iscamen.com.a [Instituto de Sanidad y Calidad Agropecuaria de Mendoza (ISCAMEN), Mendoza (Argentina); Vera, M. Teresa [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), (Argentina); Yusef, Veronica [Comision Nacional de Energia Atomica (Argentina). Centro Atomico Ezeiza; Oviedo, Andrea [Estacion Experimental Agroindustrial Obispo Colombres (EEAOC), Tucuman (Argentina)

    2006-07-01

    Field identification of released sterile insects is a major issue for eradication and suppression programs. Irradiated flies are normally identified by the presence of a fluorescent dye. When a fly lacks fluorescent dye, determination of gonadal state is necessary to identified between sterile or fertile flies. This is particularly relevant when population levels have decreased. Animal and identification is required to be as unequivocal as possible. Here we describe the reproductive system of irradiated Anastrepha fraterculus of different ages and we compare it with that of fertile flies in order to provide a diagnosis tool. Fertile and irradiated A. fraterculus were dissected from the day of emergence and until 15 days of age. Gross morphology was described and the gonads were measured. Germ cells were visualized in the testis. The reproductive systems of both males and females contained the same structures as other Anastrepha species. From day 1 to day 3, there were no detectable differences between irradiated and fertile males. The growing region encompassed half the testis total length and there was no free sperm in the seminal vesicle. On day 4 the presence of free sperm was seen in the seminal vesicle. At this stage irradiated males started differentiating from fertile ones: the growing region reduced in size and totally disappeared by day 11; sperm bundle zones occupied most of the testis; spermatids lost their triangular shape and sperm remained in the seminal vesicle without moving into the apical region. Testis length and width of irradiated males did not differ from fertile males. In females, the maturation of the ovaries involved a change in size that was more pronounced in the length of the ovary. This became noticeable at day 3. At this stage, the formation of yolk and the basal follicle began in fertile females and the oocyte had the same size as the trophocytes. From this point, the oocyte started growing. After day 8, the maturing oocyte reached

  13. Morphological characterization of the reproductive system of irradiated Anastrepha fraterculus

    International Nuclear Information System (INIS)

    Bartolucci, Andrea; Vera, M. Teresa; Yusef, Veronica

    2006-01-01

    Field identification of released sterile insects is a major issue for eradication and suppression programs. Irradiated flies are normally identified by the presence of a fluorescent dye. When a fly lacks fluorescent dye, determination of gonadal state is necessary to identified between sterile or fertile flies. This is particularly relevant when population levels have decreased. Animal and identification is required to be as unequivocal as possible. Here we describe the reproductive system of irradiated Anastrepha fraterculus of different ages and we compare it with that of fertile flies in order to provide a diagnosis tool. Fertile and irradiated A. fraterculus were dissected from the day of emergence and until 15 days of age. Gross morphology was described and the gonads were measured. Germ cells were visualized in the testis. The reproductive systems of both males and females contained the same structures as other Anastrepha species. From day 1 to day 3, there were no detectable differences between irradiated and fertile males. The growing region encompassed half the testis total length and there was no free sperm in the seminal vesicle. On day 4 the presence of free sperm was seen in the seminal vesicle. At this stage irradiated males started differentiating from fertile ones: the growing region reduced in size and totally disappeared by day 11; sperm bundle zones occupied most of the testis; spermatids lost their triangular shape and sperm remained in the seminal vesicle without moving into the apical region. Testis length and width of irradiated males did not differ from fertile males. In females, the maturation of the ovaries involved a change in size that was more pronounced in the length of the ovary. This became noticeable at day 3. At this stage, the formation of yolk and the basal follicle began in fertile females and the oocyte had the same size as the trophocytes. From this point, the oocyte started growing. After day 8, the maturing oocyte reached

  14. Influences of chemical aging on the surface morphology and crystallization behavior of basaltic glass fibers

    DEFF Research Database (Denmark)

    Lund, Majbritt Deichgræber; Yue, Yuanzheng

    2008-01-01

    The impact of aging in high humidity and water on the surface morphology and crystallization behavior of basaltic glass fibers has been studied using scanning electron microscopy, transmission electron microscopy, calorimetry and X-ray diffraction. The results show that interaction between...... the fibers and the surrounding media (high humidity or water at 70 C) leads to chemical changes strongly affecting the surface morphology. The crystallization peak temperature of the basaltic glass fibers are increased without changing the onset temperature, this may be caused by a chemical depletion...

  15. Influence of surface physicochemistry and morphology of TA6V substrates on the mechanical resistance of thin layers of alumina

    International Nuclear Information System (INIS)

    Abgrall, E.; Desmaison, J.; Haure, T.; Tixier, C.; Jonnard, P.

    2004-01-01

    Substrate surface preparation before chemical vapor deposition is an important step for the adhesion. This study describes the influence of the temperature and the RF bias during in-situ argon plasma treatment on TA6V substrates just before plasma enhanced chemical vapor deposition (PECVD) of alumina. Substrates were treated under oxygen plasma without introducing aluminum precursor during 90 seconds under process PECVD conditions that were later used for coatings development. The surface of the samples is analyzed by electron induced X-ray emission spectroscopy to study the physicochemical environment around the aluminum atoms. Atomic force microscopy (AFM) allowed to show the treatment impact on the surface morphology of the substrates. Coatings were characterized by the multicracking 4-point bending test. The results pointed out that the polarization value has a minor effect, whereas the temperature has a major influence. (orig.)

  16. Morphology and grain structure evolution during epitaxial growth of Ag films on native-oxide-covered Si surface

    International Nuclear Information System (INIS)

    Hur, Tae-Bong; Kim, Hong Koo; Perello, David; Yun, Minhee; Kulovits, Andreas; Wiezorek, Joerg

    2008-01-01

    Epitaxial nanocrystalline Ag films were grown on initially native-oxide-covered Si(001) substrates using radio-frequency magnetron sputtering. Mechanisms of grain growth and morphology evolution were investigated. An epitaxially oriented Ag layer (∼5 nm thick) formed on the oxide-desorbed Si surface during the initial growth phase. After a period of growth instability, characterized as kinetic roughening, grain growth stagnation, and increase of step-edge density, a layer of nanocrystalline Ag grains with a uniform size distribution appeared on the quasi-two-dimensional layer. This hierarchical process of film formation is attributed to the dynamic interplay between incoming energetic Ag particles and native oxide. The cyclic interaction (desorption and migration) of the oxide with the growing Ag film is found to play a crucial role in the characteristic evolution of grain growth and morphology change involving an interval of grain growth stagnation

  17. Heat treatment effects on the surface morphology and optical properties of ZnO nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Zainizan Sahdan, M. [Faculty of Electrical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Faculty of Electrical and Electronics Engineering, Universiti Tun Hussein onn Malaysia, 86400 Batu Pahat, Johor (Malaysia); Hafiz Mamat, M.; Salina, M.; Noor, Uzer M.; Rusop, Mohamad [Faculty of Electrical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Khusaimi, Zuraida [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2010-09-15

    Zinc oxide (ZnO) nanostructures have received broad attention due to its wide applications especially for thin-film solar cells and transistors. In this paper, we report the effects of heat treatment on the structural and optical properties of ZnO nanostructures. Zinc oxide nanostructures were synthesized using thermal chemical vapour deposition (CVD) method on glass substrate. The surface morphologies which were observed by scanning electron microscope (SEM) show that ZnO nanostructures change its shape and size when the annealing temperature increases from 400 C to 600 C. Structural measurement using X-ray diffraction (XRD) has shown that ZnO nanostructures have the highest crystallinity and smallest crystallite size (20 nm) when annealed at 550 C. Furthermore, the samples were optically characterized using Photoluminescence (PL) spectrometer. The PL spectra indicate that ZnO nanostructures have the highest peak at UV wavelength when annealed at 550 C. The mechanism of the PL properties of ZnO nanostructures is also discussed. We conclude that ZnO nanostructures deposited using thermal CVD have the optimum structural and PL properties when annealed at 550 C. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Surface Characterization of a Paper Web at the Wet End

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  19. Surface Characterization of a Paper Web at the Wet End

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-06-23

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

  20. Morphological and Molecular Characterization of Human Dermal Lymphatic Collectors.

    Directory of Open Access Journals (Sweden)

    Viktoria Hasselhof

    Full Text Available Millions of patients suffer from lymphedema worldwide. Supporting the contractility of lymphatic collectors is an attractive target for pharmacological therapy of lymphedema. However, lymphatics have mostly been studied in animals, while the cellular and molecular characteristics of human lymphatic collectors are largely unknown. We studied epifascial lymphatic collectors of the thigh, which were isolated for autologous transplantations. Our immunohistological studies identify additional markers for LECs (vimentin, CCBE1. We show and confirm differences between initial and collecting lymphatics concerning the markers ESAM1, D2-40 and LYVE-1. Our transmission electron microscopic studies reveal two types of smooth muscle cells (SMCs in the media of the collectors with dark and light cytoplasm. We observed vasa vasorum in the media of the largest collectors, as well as interstitial Cajal-like cells, which are highly ramified cells with long processes, caveolae, and lacking a basal lamina. They are in close contact with SMCs, which possess multiple caveolae at the contact sites. Immunohistologically we identified such cells with antibodies against vimentin and PDGFRα, but not CD34 and cKIT. With Next Generation Sequencing we searched for highly expressed genes in the media of lymphatic collectors, and found therapeutic targets, suitable for acceleration of lymphatic contractility, such as neuropeptide Y receptors 1, and 5; tachykinin receptors 1, and 2; purinergic receptors P2RX1, and 6, P2RY12, 13, and 14; 5-hydroxytryptamine receptors HTR2B, and 3C; and adrenoceptors α2A,B,C. Our studies represent the first comprehensive characterization of human epifascial lymphatic collectors, as a prerequisite for diagnosis and therapy.

  1. Optical properties and surface morphology studies of palladium contacts on mercuric iodide single crystals

    Energy Technology Data Exchange (ETDEWEB)

    George, M.A.; Azoulay, M.; Burger, A.; Biao, Y.; Silberman, E. [Fisk Univ., Nashville, TN (United States). Dept. of Physics; Nason, D. [EG and G Energy Measurements, Inc., Goleta, CA (United States). Santa Barbara Operations

    1993-05-01

    Palladium is chemically suitable for electric contacts on mercuric iodide detectors for photon and nuclear radiation detection, so the understanding of palladium contacts is important for fundamental and practical scientific purposes. A study has been conducted on the surface morphology of evaporated contacts using Atomic Force Microscopy (AFM) and optical transmission and reflection. Evaporated palladium coatings are typically nonuniform and may deposit selectively on mercuric iodide surface defects. Reflection measurements show that coating thickness and surface treatment affect intensity, position and shape of a reflected peak characteristic of the mercuric iodide structure. Results indicate that the band gap energy in the surface of the mercuric iodide is lowered by palladium contacts.

  2. Silver nanocrystals of various morphologies deposited on silicon wafer and their applications in ultrasensitive surface-enhanced Raman scattering

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Limiao, E-mail: chenlimiao@csu.edu.cn; Jing, Qifeng; Chen, Jun; Wang, Bodong; Huang, Jianhan; Liu, Younian

    2013-11-15

    Silver nanostructures with dendritic, flower-like and irregular morphologies were controllably deposited on a silicon substrate in an aqueous hydrogen fluoride solution at room temperature. The morphology of the Ag nanostructures changed from dendritic to urchin-like, flowerlike and pinecone-like with increasing the concentration of polyvinyl pyrrolidone (MW = 55,000) from 2 to 10 mM. The Ag nanostructures were characterized by transmission electron microscopy, high-resolution transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray, and X-ray diffraction. Through a series of time-dependent morphological evolution studies, the growth processes of Ag nanostructures have been systematically investigated and the corresponding growth mechanisms have been discussed. In addition, the morphology-dependent surface-enhanced Raman scattering of as-synthesized Ag nanostructures were investigated. The results indicated that flower-like Ag nanostructure had the highest activity than the other Ag nanostructures for Rhodamine 6G probe molecules. Highlights: • A simple method was developed to prepare dendritic and flower-like Ag nanostructures. • The flower-like Ag nanoparticles exhibit highest SERS activity. • The SERS substrate based on flower-like Ag particles can be used to detect melamine.

  3. Morphological and molecular characterization of Fusarium spp pathogenic to pecan tree in Brazil.

    Science.gov (United States)

    Lazarotto, M; Milanesi, P M; Muniz, M F B; Reiniger, L R S; Beltrame, R; Harakava, R; Blume, E

    2014-11-11

    The occurrence of Fusarium spp associated with pecan tree (Carya illinoinensis) diseases in Brazil has been observed in recent laboratory analyses in Rio Grande do Sul State. Thus, in this study, we i) obtained Fusarium isolates from plants with disease symptoms; ii) tested the pathogenicity of these Fusarium isolates to pecan; iii) characterized and grouped Fusarium isolates that were pathogenic to the pecan tree based on morphological characteristics; iv) identified Fusarium spp to the species complex level through TEF-1α sequencing; and v) compared the identification methods used in the study. Fifteen isolates collected from the inflorescences, roots, and seeds of symptomatic plants (leaf necrosis or root rot) were used for pathogenicity tests. Morphological characterization was conducted using only pathogenic isolates, for a total of 11 isolates, based on the mycelial growth rate, sporulation, colony pigmentation, and conidial length and width variables. Pathogenic isolates were grouped based on morphological characteristics, and molecular characterization was performed by sequencing TEF-1α genes. Pathogenic isolates belonging to the Fusarium chlamydosporum species complex, Fusarium graminearum species complex, Fusarium proliferatum, and Fusarium oxysporum were identified based on the TEF-1α region. Morphological characteristics were used to effectively differentiate isolates and group the isolates according to genetic similarity, particularly conidial width, which emerged as a key morphological descriptor in this study.

  4. [Morphology of cracks in enamel surface produced experimentally using high and low temperature].

    Science.gov (United States)

    Suárez Quintanilla, J; Segade, L A; González Bahillo, J

    1989-12-01

    A scanning electron microscope study was made to study the morphological changes in the human enamel surface produced by low and high temperatures. Cracked dental enamel was observed when the teeth were exposed at low and high temperatures. When the time of exposition was increased, there are more enamel cracks which may be considered as enamel fractures.

  5. Surface Morphology and Optical Properties of 3 Porphyrin/Au and Au/Porphyrin/Au Systems

    Czech Academy of Sciences Publication Activity Database

    Kalachyova, Y.; Lyutakov, O.; Solovyev, Andrey; Slepička, P.; Švorčík, V.

    2013-01-01

    Roč. 8, DEC 27 (2013), s. 547 ISSN 1931-7573 Grant - others:GA ČR(CZ) GPP108/11/P840; GA ČR(CZ) GAP108/12/1168 Program:GA Institutional support: RVO:67985858 Keywords : nanostructures * gold * porphyrin * luminescence * enhancement * surface morphology Subject RIV: JJ - Other Materials Impact factor: 2.524, year: 2012

  6. The theory of development of surface morphology by sputter erosion processes

    International Nuclear Information System (INIS)

    Carter, G.; Nobes, M.J.

    1984-01-01

    When a surface is bombarded by an energetic ion flux a rich variety of surface structures are observed to develop at the atomic, microscopic and macroscopic scales. Such structures include elevated, with respect to the surrounding surface, features such as mesas or plateaux, ridges, cones and pyramids and depressed features such as etch pits and cavities. These elementary features may be isolated or in profusion and frequently repetitive patterns of coordinated pyramidal structures, etch pits, surface ledges or facets and ripple or wave-like structures occur. The majority of the features arise rather directly from the erosion action of the sputtering process, particularly from differential erosion processes at different surface localities. The authors outline a general approach to sputter erosion induced surface morphology development based on the concept of the surface as an advancing wave. (Auth.)

  7. Atomic force microscopy characterization of the surface wettability of natural fibres

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  8. Morphological characterization of ceramic fillers made from Indonesian natural sand as restorative dental materials

    Science.gov (United States)

    Karlina, E.; Susra, S.; Fatmala, Y.; Hartoyo, H. M.; Takarini, V.; Usri, K.; Febrida, R.; Djustiana, N.; Panatarani, C.; Joni, I. M.

    2018-02-01

    Dental composite as restorative dental materials can be reinforced using ceramic fillers. Homogeneous distribution of filler particles shall improve its mechanical properties. This paper presents the results of the preliminary study on the ZrO2-Al2O3-SiO2 ceramic fillers made from Indonesian natural sand that can increase the mechanical properties of dental composite. The synthesis was done using zirconium silicate sand (ZrSiO4) and aluminium oxide (Al2O3) precursors, which dissolved together with 70:30 weight ratios. Two types of sand were used: (1) manufactured sand (mesh #80) and (2) natural sand (mesh #400). The samples then heated in the furnace at 1100 °C for 8 hours. The morphological characterization was then evaluated using JEOL Scanning Electron Microscope (SEM) for the surface structure that analyze particles size and distribution. Ceramic fillers made from natural sand is homogenous, well distributed with average particle size of 5-10 µm. Comparably, ceramic filler made from the manufactured sand is heterogeneous, poorly distributed and appear as agglomerates with average particle size are 30-50 µm. The results suggest that ceramic fillers made from natural sand demonstrate better character to represent as a functional restorative dental material.

  9. Morphologic and proteomic characterization of exosomes released by cultured extravillous trophoblast cells

    Energy Technology Data Exchange (ETDEWEB)

    Atay, Safinur [Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, KY (United States); Gercel-Taylor, Cicek [Obstetrics, Gynecology and Women' s Health, University of Louisville School of Medicine, Louisville, KY (United States); Kesimer, Mehmet [Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States); Taylor, Douglas D., E-mail: ddtaylor@louisville.edu [Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, KY (United States); Obstetrics, Gynecology and Women' s Health, University of Louisville School of Medicine, Louisville, KY (United States)

    2011-05-01

    Exosomes represent an important intercellular communication vehicle, mediating events essential for the decidual microenvironment. While we have demonstrated exosome induction of pro-inflammatory cytokines, to date, no extensive characterization of trophoblast-derived exosomes has been provided. Our objective was to provide a morphologic and proteomic characterization of these exosomes. Exosomes were isolated from the conditioned media of Swan71 human trophoblast cells by ultrafiltration and ultracentrifugation. These were analyzed for density (sucrose density gradient centrifugation), morphology (electron microscopy), size (dynamic light scattering) and protein composition (Ion Trap mass spectrometry and western immunoblotting). Based on density gradient centrifugation, microvesicles from Sw71 cells exhibit a density between 1.134 and 1.173 g/ml. Electron microscopy demonstrated that microvesicles from Sw71 cells exhibit the characteristic cup-shaped morphology of exosomes. Dynamic light scattering showed a bell-shaped curve, indicating a homogeneous population with a mean size of 165 nm {+-} 0.5 nm. Ion Trap mass spectrometry demonstrated the presence of exosome marker proteins (including CD81, Alix, cytoskeleton related proteins, and Rab family). The MS results were confirmed by western immunoblotting. Based on morphology, density, size and protein composition, we defined the release of exosomes from extravillous trophoblast cells and provide their first extensive characterization. This characterization is essential in furthering our understanding of 'normal' early pregnancy.

  10. Study of the Effect of Nanoparticles and Surface Morphology on Reverse Osmosis and Nanofiltration Membrane Productivity

    Directory of Open Access Journals (Sweden)

    Steven J. Duranceau

    2013-08-01

    Full Text Available To evaluate the significance of reverse osmosis (RO and nanofiltration (NF surface morphology on membrane performance, productivity experiments were conducted using flat-sheet membranes and three different nanoparticles, which included SiO2, TiO2 and CeO2. In this study, the productivity rate was markedly influenced by membrane surface morphology. Atomic force microscopy (AFM analysis of membrane surfaces revealed that the higher productivity decline rates associated with polyamide RO membranes as compared to that of a cellulose acetate NF membrane was due to the inherent ridge-and-valley morphology of the active layer. The unique polyamide active layer morphology was directly related to the surface roughness, and was found to contribute to particle accumulation in the valleys causing a higher flux decline than in smoother membranes. Extended RO productivity experiments using laboratory grade water and diluted pretreated seawater were conducted to compare the effect that different nanoparticles had on membrane active layers. Membrane flux decline was not affected by particle type when the feed water was laboratory grade water. On the other hand, membrane productivity was affected by particle type when pretreated diluted seawater served as feed water. It was found that CeO2 addition resulted in the least observable flux decline, followed by SiO2 and TiO2. A productivity simulation was conducted by fitting the monitored flux data into a cake growth rate model, where the model was modified using a finite difference method to incorporate surface thickness variation into the analysis. The ratio of cake growth term (k1 and particle back diffusion term (k2 was compared in between different RO and NF membranes. Results indicated that k2 was less significant for surfaces that exhibited a higher roughness. It was concluded that the valley areas of thin-film membrane surfaces have the ability to capture particles, limiting particle back diffusion.

  11. Structural, morphological and magnetic characterization of electrodeposited Co–Fe–W alloys

    Energy Technology Data Exchange (ETDEWEB)

    Noce, R. Della, E-mail: rodrnoce@iq.unesp.br [Instituto de Química, Universidade Estadual Paulista, UNESP, 14800-900 Araraquara, SP (Brazil); Benedetti, A.V.; Magnani, M. [Instituto de Química, Universidade Estadual Paulista, UNESP, 14800-900 Araraquara, SP (Brazil); Passamani, E.C. [Departamento de Física, Universidade Federal do Espírito Santo, 29075-910 Vitória, ES (Brazil); Kumar, H.; Cornejo, D.R. [Instituto de Física, Universidade de São Paulo, USP, 05508-090 São Paulo, SP (Brazil); Ospina, C.A. [Electron Microscopy Laboratory, Brazilian Nanotechnology National Laboratory, 13083-970 Campinas, SP (Brazil)

    2014-10-25

    Highlights: • Small W additions (up to 9 at.%) to the Co{sub 35}Fe{sub 65} binary system. • Electrodeposited Co–Fe–W alloys characterization by XRD, SEM, TEM, Mössbauer spectroscopy and magnetic measurements. • Production of Co–Fe–W alloys with low values of coercivity and high saturation magnetization. • Potential materials for applications in magnetic devices such as read/write heads and hard disks. - Abstract: Structural, morphological and magnetic characterization of electrodeposited Co–Fe–W alloys, containing small amounts of W (up to 9 at.%), were performed using X-ray diffractometry, scanning (SEM) and transmission (TEM) electron microscopy, Mössbauer spectroscopy and magnetization measurements. Electrodeposited (Co{sub 100−x}Fe{sub x}){sub 100−y}W{sub y} films (x = 63–72 at.% Fe, y = 4–9 at.% W) were successfully produced varying the applied cathodic current density (i{sub c}) between 0.5 and 10 mA cm{sup −2}. X-ray diffraction results revealed a bcc-like structure for all studied compositions with average crystallite size ranging from 16 to 35 nm, as also confirmed by TEM results. SEM images indicated that needle-type morphology is dominant for the deposits containing lower W content (up to 4.5 at.%.), while a cauliflower-type behavior is observed for higher W content deposits. Room temperature Mössbauer spectra indicate the presence of two magnetic species for all samples; one component associated with an ordered Co–Fe–W fraction (crystalline grain core) and a magnetic disordered Co–Fe–W contribution, which can be attributed to the grain boundaries/grain surfaces. Magnetization was observed to be in the film plane along the film direction, except the sample prepared at i{sub c} = 10 mA cm{sup −2} that is slightly canted from in- to out-of-plane geometry. Magnetic measurements show high saturation magnetization values accompanied by low coercivity ones for the electrodeposited Co–Fe–W alloys, making these

  12. Morphology, stresses, and surface reactivity of nanoporous gold synthesized from nanostructured precursor alloys

    Science.gov (United States)

    Rouya, Eric

    Nanoporous metallic materials (NMMs) are generally synthesized using dealloying, whereby the more reactive component is dissolved from a homogeneous alloy in a suitable electrolyte, and the more noble metal atoms simultaneously diffuse into 3-D clusters, forming a bi-continuous network of interconnected ligaments. Nanoporous gold (NPG) in particular is a well-known NMM; it is inert, bio-compatible, and capable of developing large surface areas with 1--100nm pores. While several studies have demonstrated its potential usefulness in fuel cell and sensing devices, its structural, mechanical, and electrocatalytic properties still require further investigation, particularly if NPG is synthesized from precursor alloy films exhibiting metastable nanostructures. In this dissertation, the electrodeposition (ECD) process, microstrucural characteristics, and metatstability of Au-Ni precursor alloys are investigated. The stresses evolved during Au-Ni alloy nucleation and growth are investigated in situ and correlated with microstructural and electrochemical data in order to identify the various stress-inducing mechanisms. In situ stresses generated during Au-Ni and Au-Ag dealloying were investigated, and additionally correlated with the growth stresses. Finally, the surface area and electrocatalytic properties of NPG are characterized using a variety of electrochemical techniques. Potentiostatically electrodeposited Au1-x-Nix (x: 0--90at%) films form a continuous series of metastable solid solutions and exhibit a nanocrystalline morphology, with ˜10--20 nm grains, the size of which decreases with increasing Ni content. The formation of a metastable structure was interpreted in terms of the limited surface diffusivities of adatoms at the growing interface and atomic volume differences (˜15%). Internal stresses generated during ECD of Ni-rich films can be explained assuming a 3-D Volmer-Weber growth mode, where the stress is initially compressive, then transitions into tension

  13. Leachate characterization and assessment of surface and ...

    African Journals Online (AJOL)

    The environment can be impacted negatively by leachates from these dumpsites if not properly managed. This study aimed at assessing the characteristics of municipal solid waste leachate and its contamination potential on surface and groundwater. Leachate, groundwater and surface water samples were collected from ...

  14. Egypt satellite images for land surface characterization

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay

    Satellite images provide information on the land surface properties. From optical remote sensing images in the blue, green, red and near-infrared part of the electromagnetic spectrum it is possible to identify a large number of surface features. The report briefly describes different satellite...

  15. Surface morphology changes of acrylic resins during finishing and polishing phases

    Directory of Open Access Journals (Sweden)

    Glaucio Serra

    2013-12-01

    Full Text Available INTRODUCTION: The finishing and polishing phases are essential to improve smoothness and shining on the surface of acrylic resins used to make removable orthodontic appliances. A good surface finishing reduces roughness, which facilitates hygiene, prevents staining and provides greater comfort to the patients. OBJECTIVE: The aim of this paper was to analyze the changes on surface morphology of acrylic resins during finishing and polishing phases. METHODS: Thirty discs (10 mm in diameter and 5 mm in length were made with acrylic resin and randomly divided into ten groups. The control group did not receive any treatment while the other groups received gradual finishing and polishing. The last group received the entire finishing and polishing procedures. Surface morphology was qualitatively analyzed through scanning electron microscopy and quantitatively analyzed through a laser profilometer test. RESULTS: The acrylic resin surfaces without treatment showed bubbles which were not observed in the subsequent phases. Wearing out with multilaminated burs, finishing with wood sandpaper and finishing with water sandpaper resulted in surfaces with decreasing irregularities. The surfaces that were polished with pumice and with low abrasive liquids showed high superficial smoothness. CONCLUSION: Highly smooth acrylic resin surfaces can be obtained after mechanical finishing and polishing performed with multilaminated burs, wood sandpaper, water sandpaper, pumice and low abrasive liquids.

  16. Kimpul (Xanthosoma spp. characterization based on morphological characteristic and isozymic analysis

    Directory of Open Access Journals (Sweden)

    SAJIDAN

    2009-11-01

    Full Text Available Nurmiyati, Sugiyarto, Sajidan. 2009. Kimpul (Xanthosoma spp. characterization based on morphological characteristic and isozymic analysis. Nusantara Bioscience 1: 138-145. This research is aimed: (i to know the variety of kimpul (Xanthosoma spp. based on morphological characteristics and isozymes analysis; (ii to know the correlation between its genetic space based on morphological characteristics and its genetic resemblance based on isozymes-banding pattern. This research results were analyzed and described by descriptive qualitative methods. Morphological observation was carried out in sub-District of Galur, Lendah and Girimulyo, Kulonprogo District, Yogyakarta. Morphological data of the kimpul plant was explored descriptively and then made dendogram. Data of isozymic banding pattern were analyzed quantitatively based on the appearance of the band on the gel, and qualitatively based on the thickness of the band formed, and then made dendogram. The correlation, between its genetic distance based on morphological characteristics and its genetic resemblance based on isozymes-banding pattern, were then analyzed grounded on coefficient correlation between product-moment and goodness of it criteria based on correlation. The results pointed out that morphologically, on eight observed samples which were consist of four different types (species, each Xanthosoma from different locations did not indicate obvious differences. Esterase was formed four different banding-patterns, Glutamate Oxaloacetate Transaminase indicated eight different banding-patterns, and Peroxidase indicated seven different banding-patterns. Correlation between morphological data and data from EST and GOT isozymic banding pattern were very good (0.967918 and 0.937113, While, the correlations between morphological data and POD isozymes were good (0.892721.

  17. Dry Etching of Copper Phthalocyanine Thin Films: Effects on Morphology and Surface Stoichiometry

    Directory of Open Access Journals (Sweden)

    Michael J. Brett

    2012-08-01

    Full Text Available We investigate the evolution of copper phthalocyanine thin films as they are etched with argon plasma. Significant morphological changes occur as a result of the ion bombardment; a planar surface quickly becomes an array of nanopillars which are less than 20 nm in diameter. The changes in morphology are independent of plasma power, which controls the etch rate only. Analysis by X-ray photoelectron spectroscopy shows that surface concentrations of copper and oxygen increase with etch time, while carbon and nitrogen are depleted. Despite these changes in surface stoichiometry, we observe no effect on the work function. The absorbance and X-ray diffraction spectra show no changes other than the peaks diminishing with etch time. These findings have important implications for organic photovoltaic devices which seek nanopillar thin films of metal phthalocyanine materials as an optimal structure.

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

    International Nuclear Information System (INIS)

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

    1998-08-01

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

  19. IR and UV laser-induced morphological changes in silicon surface under oxygen atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Jarquin, J.; Fernandez-Guasti, M.; Haro-Poniatowski, E.; Hernandez-Pozos, J.L. [Laboratorio de Optica Cuantica, Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco No. 186, Col. Vicentina, C.P. 09340, Mexico D.F. (Mexico)

    2005-08-01

    We irradiated silicon (100) wafers with IR (1064 nm) and UV (355 nm) nanosecond laser pulses with energy densities within the ablation regime and used scanning electron microscopy to analyze the morphological changes induced on the Si surface. The changes in the wafer morphology depend both on the incident radiation wavelength and the environmental atmosphere. We have patterned Si surfaces with a single focused laser spot and, in doing the experiments with IR or UV this reveals significant differences in the initial surface cracking and pattern formation, however if the experiment is carried out in O{sub 2} the final result is an array of microcones. We also employed a random scanning technique to irradiate the silicon wafer over large areas, in this case the microstructure patterns consist of a ''semi-ordered'' array of micron-sized cones. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Problems of surface morphology and layer deposition during plasma etching processes. 2

    International Nuclear Information System (INIS)

    Tiller, H.-J.; Krausse, J.; Voigt, R.

    1982-01-01

    The plasma etching of Si in CF 4 -, CF 4 /O 2 - and CF 4 /H 2 plasmas was investigated in dependence on the etching gas, the plasma conditions (pressure, power density) and etching time in different reactors. A roughening of the surface and the formation of a 'semi-amorphous' surface layer with a powder-like morphology was detected by TEM-and RHEED methods. It is supposed that the surface layer has a fundamental consequence as an intermediate state in the etching mechanism. (author)

  1. Dynamic Mechanical Properties and Fracture Surface Morphologies of Core-Shell Rubber (CSR) Toughened Epoxy at Liquid Nitrogen (Ln2) Temperatures

    Science.gov (United States)

    Wang, J.; Magee, D.; Schneider, J. A.

    2009-01-01

    The dynamic mechanical properties and fracture surface morphologies were evaluated for a commercial epoxy resin toughened with two types of core-shell rubber (CSR) toughening agents (Kane Ace(Registered TradeMark) MX130 and MX960). The impact resistance (R) was evaluated by the resulting breaking energy measured in Charpy impact tests conducted on an instrumented drop tower. The resulting fracture surface morphologies were examined using Scanning Electron Microscopy (SEM). Fractographic observations of the CSR toughened epoxy tested at ambient temperature, showed a fracture as characterized by slender dendrite textures with large voids. The increasing number of dendrites and decreasing size of scale-like texture with more CSR particles corresponded with increased R. As the temperature decreased to Liquid Nitrogen (LN 2), the fracture surfaces showed a fracture characterized by a rough, torn texture containing many river markings and deep furrows.

  2. Nanoparticle Surface Specific Adsorption of Zein and Its Self-assembled Behavior of Nanocubes Formation in Relation to On-Off SERS: Understanding Morphology Control of Protein Aggregates.

    Science.gov (United States)

    Navdeep; Banipal, Tarlok Singh; Kaur, Gurinder; Bakshi, Mandeep Singh

    2016-01-27

    Zein, an industrially important protein, is characterized in terms of its food and pharmaceutical coating applications by using surface enhanced Raman spectroscopy (SERS) on Au, Ag, and PbS nanoparticles (NPs). Its specific surface adsorption behavior on Ag NPs produced self-assembled zein nanocubes which demonstrated on and off SERS activity. Both SERS characterization as well as nanocube formation of zein helped us to understand the complex protein aggregation behavior in shape controlled morphologies, a process with significant ramifications in protein crystallization to achieve ordered morphologies. Interestingly, nanocube formation was promoted in the presence of Ag rather than Au or PbS NPs under in situ synthesis and discussed in terms of specific adsorption. Zein fingerprinting was much more clear and enhanced on Au surface in comparison to Ag while PbS did not demonstrate SERS due to its semiconducting nature.

  3. Surface and morphological features of laser-irradiated silicon under vacuum, nitrogen and ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Asma, E-mail: asmahayat@gcu.edu.pk; Bashir, Shazia; Akram, Mahreen; Mahmood, Khaliq; Iqbal, Muhammad Hassan

    2015-12-01

    Highlights: • Laser irradiation effects on Si surface have been explored. • An Excimer Laser was used as a source. • SEM analysis was performed to explore surface morphology. • Raman spectroscopy analysis was carried out to find crystallographical alterations. - Abstract: Laser-induced surface and structural modification of silicon (Si) has been investigated under three different environments of vacuum, nitrogen (100 Torr) and ethanol. The interaction of 1000 pulses of KrF (λ ≈ 248 nm, τ ≈ 18 ns, repetition rate ≈ 30 Hz) Excimer laser at two different fluences of 2.8 J/cm{sup 2} and 4 J/cm{sup 2} resulted in formation of various kinds of features such as laser induced periodic surface structures (LIPSS), spikes, columns, cones and cracks. Surface morphology has been observed by Scanning Electron Microscope (SEM). Whereas, structural modification of irradiated targets is explored by Raman spectroscopy. SEM analysis exhibits a non-uniform distribution of micro-scale pillars and spikes at the central ablated regime of silicon irradiated at low laser fluence of 2.8 J/cm{sup 2} under vacuum. Whereas cones, pits, cavities and ripples like features are seen at the boundaries. At higher fluence of 4 J/cm{sup 2}, laser induced periodic structures as well as micro-columns are observed. In the case of ablation in nitrogen environment, melting, splashing, self-organized granular structures and cracks along with redeposition are observed at lower fluence. Such types of small scaled structures in nitrogen are attributed to confinement and shielding effects of nitrogen plasma. Whereas, a crater with multiple ablative layers is formed in the case of ablation at higher fluence. Significantly different surface morphology of Si is observed in the case of ablation in ethanol. It reveals the formation of cavities along with small scale pores and less redeposition. These results reveal that the growth of surface and morphological features of irradiated Si are strongly

  4. Investigation on effects of surface morphologies on response of LPG sensor based on nanostructured copper ferrite system

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Satyendra [Nanomaterials and Sensors Research Laboratory, Department of Physics, University of Lucknow, Lucknow 226007, U.P. (India); Yadav, B.C., E-mail: balchandra_yadav@rediffmail.com [Nanomaterials and Sensors Research Laboratory, Department of Physics, University of Lucknow, Lucknow 226007, U.P. (India); Department of Applied Physics, School for Physical Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, U.P. (India); Gupta, V.D. [Nanomaterials and Sensors Research Laboratory, Department of Physics, University of Lucknow, Lucknow 226007, U.P. (India); Dwivedi, Prabhat K. [DST Unit on Nanosciences, Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur, U.P. (India)

    2012-11-15

    Graphical abstract: Figure shows the variations in resistance with time for copper ferrite system synthesized in various molar ratio. A maximum variation in resistance was observed for copper ferrite prepared in 1:1 molar ratio. Highlights: ► Evaluation of structural, optical and surface morphologies. ► Significant variation in LPG sensing properties. ► Surface modification of ferric oxide pellet by copper ferrite. ► CuFe{sub 2}O{sub 4} pellets for LPG sensing at room temperature. -- Abstract: Synthesis of a copper ferrite system (CuFe{sub 2}O{sub 4}) via chemical co-precipitation method is characterized by X-ray diffraction, surface morphology (scanning electron microscope) and optical absorption spectroscopy. These characteristics show their dependence on the relative compositions of the two subsystems. They are further confirmed by the variation in the band gap. A study of gas sensing properties shows the spinel CuFe{sub 2}O{sub 4} synthesized in 1:1 molar ratio exhibit best response to LPG adsorption/resistance measurement. Thus resistance based LPG sensor is found robust, cheap and may be applied for kitchens and industrial applications.

  5. Effect of fast mold surface temperature evolution on iPP part morphology gradients

    Science.gov (United States)

    Liparoti, Sara; Sorrentino, Andrea; Guzman, Gustavo; Cakmak, Mukerrem; Titomanlio, Giuseppe

    2016-03-01

    The control of mold surface temperature is an important factor that affects the sample surface morphology as well as the structural gradients (orientation crystal size, and type) as well as cooling stresses. The frozen layer thickness formed during the filling stage also has a very significant effect on the flow resistance and thus on the resulting pressure drop and flow length in thin wall parts. The possibility to have a hot mold during filling and a quick cooling soon afterward is a significant process enhancement particularly for specialized applications such as micro injection molding and for the reproduction of micro structured surfaces. Up to now, several methods (electromagnetic, infrared, hot vapor fleshing etc,) were tried to achieve fast temperature evolution of the mold. Unfortunately, all these methods require a complex balance between thermal and mechanical problems, equipment cost, energy consumption, safety, molding cycle time and part quality achievable. In this work, a thin electrical resistance was designed and used to generate a fast and confined temperature variation on mold surface (by joule effect). Since the whole temperature evolution can take place in a few seconds, one can couple the advantages of a high surface temperature during filling with the advantages of a low mold temperature, fast cooling and low heating dissipation. Some experiments were performed with a commercial iPP resin. The effects of the surface temperature and of the heating time (under constant electric power) on surface finishing and on the final morphology (thickness and structure of the different layers) are explored and discussed.

  6. Microstructural characterization of laser surface melted AISI M2 tool steel.

    Science.gov (United States)

    Arias, J; Cabeza, M; Castro, G; Feijoo, I; Merino, P; Pena, G

    2010-09-01

    We describe the microstructure of Nd:YAG continuous wave laser surface melted high-speed steel, namely AISI M2, treated with different laser scanning speeds and beam diameters on its surface. Microstructural characterization of the remelted surface layer was performed using light optical and scanning electron microscopy and X-ray diffraction. The combination of the three techniques provided new insights into the substantial changes induced by laser surface melting of the steel surface layer. The advantage of the method is that it avoids the difficult and tedious work of preparing samples of this hard material for transmission electron microscopy, which is the technique normally used to study these fine microstructures. A melted zone with a dendritic structure and a partially melted zone with a heterogeneous cellular structure were observed. M(2)C carbides with different morphologies were identified in the resolidified surface layer after laser melting.

  7. [Morphological and molecular characterization of isolates of Macrophomina phaseolina associated with sugarcane in Mexico].

    Science.gov (United States)

    Leyva-Mir, Santos G; Velázquez-Martínez, Guadalupe C; Tlapal-Bolaños, Bertha; Tovar-Pedraza, Juan M; Rosas-Saito, Greta H; Alvarado-Gómez, Omar G

    2015-01-01

    Charcoal rot caused by Macrophomina phaseolina is an important disease of sugarcane in Mexico. This study was carried out to characterize isolates of M. phaseolina obtained from sugarcane by the combination of morphological and molecular analyses. The morphological characterization of 10 isolates was performed using scanning electron microscopy and light microscopy. To confirm the morphological identification, rDNA from two representative isolates was extracted, and the internal transcribed spacer (ITS) region was amplified by polymerase chain reaction and sequenced using specific primers MpKF1 and MpKR1. Based on their morphological characteristics, all isolates were identified as M. phaseolina. Moreover, the analysis of two ITS sequences showed 100% similarity with the M. phaseolina sequences deposited in the GenBank. To our knowledge, this is the first study in the world aimed at characterizing isolates of M. phaseolina obtained from sugarcane. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  8. Characterization of neutrophil adhesion to different titanium surfaces

    Indian Academy of Sciences (India)

    ing blood; however, direct contact between the oxide layer of the implant and neutrophils has not been completely described. The aim of the present study is to compare ... Titanium surfaces; neutrophil morphology; adhesion molecules; inflammatory response; flow cytome- try; scanning electron microscopy. 1. Introduction.

  9. Surface characterization of silver and palladium modified glassy ...

    Indian Academy of Sciences (India)

    WINTEC

    Abstract. In this work, the influence of silver and palladium on the surface of undoped, boron doped and phosphorus doped glassy carbon has been studied. The silver and palladium concentrations in solution, after metal deposition, were measured by atomic absorption spectrophotometer. The morphology of metal coatings.

  10. Bio-Tribology Properties of Bionic Carp Scale Morphology on Ti6A14V Surface

    Science.gov (United States)

    Wang, W.; Y Wei, X.; Meng, K.; Zhong, L. H.; Wang, Y.; Yu, X. H.

    2017-12-01

    In order to improve the bio-tribology properties of Ti6A14V surface, the bionic carp scale appearance pattern on Ti6A14V surface was prepared by laser surface texturing technology. The ball-disc reciprocating linear tribological experiment under different lubricants with dry friction was carried out by MRTR multifunction friction and wear testing machine using ZrO2/Ti6A14V as friction pair. The wear scar morphology of the sample surface was observed by SEM. The results show that for dry friction, the friction factor of the bionic carp scale morphology Ti6A14V reduces by 0.23 than those without bionic carp scale morphology, a decline of 45%. Under different lubrication conditions, the friction factors of samples with the bionic carp scale are increased in varying degrees with the increase of size of bionic texturing. The friction factor with same specimen under different lubrication conditions according to the ascending order are 0.5g/dl of sodium hyaluronate +0.5g/dl-γglobulin and 0.5g/dl mixed aqueous solution of sodium hyaluronate solution and artificial saliva. The wear volume also showed a similar variation.

  11. The effect of surface morphology on the primary fixation strength of uncemented femoral knee prosthesis: a cadaveric study

    NARCIS (Netherlands)

    Berahmani, S.; Janssen, D.W.; Wolfson, D.; Rivard, K.; Waal Malefijt, M.C. de; Verdonschot, N.J.

    2015-01-01

    We investigated the effect of surface morphology on the mechanical performance of uncemented femoral knee prosthesis. Eighteen implants were implanted on nine paired femurs and then pushed-off (left legs: a novel surface morphology; right legs: Porocoat as baseline). Bone mineral density (BMD) and

  12. A semi-automated Raman micro-spectroscopy method for morphological and chemical characterizations of microplastic litter.

    Science.gov (United States)

    L, Frère; I, Paul-Pont; J, Moreau; P, Soudant; C, Lambert; A, Huvet; E, Rinnert

    2016-12-15

    Every step of microplastic analysis (collection, extraction and characterization) is time-consuming, representing an obstacle to the implementation of large scale monitoring. This study proposes a semi-automated Raman micro-spectroscopy method coupled to static image analysis that allows the screening of a large quantity of microplastic in a time-effective way with minimal machine operator intervention. The method was validated using 103 particles collected at the sea surface spiked with 7 standard plastics: morphological and chemical characterization of particles was performed in environmental sample (n=962 particles). The identification rate was 75% and significantly decreased as a function of particle size. Microplastics represented 71% of the identified particles and significant size differences were observed: polystyrene was mainly found in the 2-5mm range (59%), polyethylene in the 1-2mm range (40%) and polypropylene in the 0.335-1mm range (42%). Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Tailorable Surface Morphology of 3D Scaffolds by Combining Additive Manufacturing with Thermally Induced Phase Separation.

    Science.gov (United States)

    Di Luca, Andrea; de Wijn, Joost R; van Blitterswijk, Clemens A; Camarero-Espinosa, Sandra; Moroni, Lorenzo

    2017-08-01

    The functionalization of biomaterials substrates used for cell culture is gearing towards an increasing control over cell activity. Although a number of biomaterials have been successfully modified by different strategies to display tailored physical and chemical surface properties, it is still challenging to step from 2D substrates to 3D scaffolds with instructive surface properties for cell culture and tissue regeneration. In this study, additive manufacturing and thermally induced phase separation are combined to create 3D scaffolds with tunable surface morphology from polymer gels. Surface features vary depending on the gel concentration, the exchanging temperature, and the nonsolvent used. When preosteoblasts (MC-3T3 cells) are cultured on these scaffolds, a significant increase in alkaline phosphatase activity is measured for submicron surface topography, suggesting a potential role on early cell differentiation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Surface roughness and morphology of dental nanocomposites polished by four different procedures evaluated by a multifractal approach

    Energy Technology Data Exchange (ETDEWEB)

    Ţălu, Ştefan, E-mail: stefan_ta@yahoo.com [Technical University of Cluj-Napoca, Faculty of Mechanical Engineering, Department of AET, Discipline of Descriptive Geometry and Engineering Graphics, 103-105 B-dul Muncii St., Cluj-Napoca 400641, Cluj (Romania); Stach, Sebastian, E-mail: sebastian.stach@us.edu.pl [University of Silesia, Faculty of Computer Science and Materials Science, Institute of Informatics, Department of Biomedical Computer Systems, Będzińska 39, 41-205 Sosnowiec (Poland); Lainović, Tijana, E-mail: tijana.lainovic@gmail.com [University of Novi Sad, Faculty of Medicine, School of Dentistry, Hajduk Veljkova 3, 21000 Novi Sad (Serbia); Vilotić, Marko, E-mail: markovil@uns.ac.rs [University of Novi Sad, Faculty of Technical Sciences, Department for Production Engineering, Trg Dositeja Obradovića 6, 21000 Novi Sad (Serbia); Blažić, Larisa, E-mail: larisa.blazic@gmail.com [University of Novi Sad, Faculty of Medicine, School of Dentistry, Clinic of Dentistry of Vojvodina, Department of Restorative Dentistry and Endodontics, Hajduk Veljkova 3, 21000 Novi Sad (Serbia); Alb, Sandu Florin, E-mail: albflorin@yahoo.com [“Iuliu Haţieganu” University of Medicine and Pharmacy, Faculty of Dentistry, Department of Periodontology, 8 Victor Babeş St., 400012 Cluj-Napoca (Romania); Kakaš, Damir, E-mail: kakasdam@uns.ac.rs [University of Novi Sad, Faculty of Technical Sciences, Department for Production Engineering, Trg Dositeja Obradovića 6, 21000 Novi Sad (Serbia)

    2015-03-01

    Graphical abstract: - Highlights: • Multifractals are good indicators of polished dental composites 3-D surface structure. • The nanofilled composite had superior 3-D surface properties than the nanohybrid one. • Composite polishing with diamond paste created improved 3-D multifractal structure. • Recommendation: polish the composite with diamond paste if using the one-step tool. • Multifractal analysis could become essential in designing new dental surfaces. - Abstract: The objective of this study was to determine the effect of different dental polishing methods on surface texture parameters of dental nanocomposites. The 3-D surface morphology was investigated by atomic force microscopy (AFM) and multifractal analysis. Two representative dental resin-based nanocomposites were investigated: a nanofilled and a nanohybrid composite. The samples were polished by two dental polishing protocols using multi-step and one-step system. Both protocols were then followed by diamond paste polishing. The 3-D surface roughness of samples was studied by AFM on square areas of topography on the 80 × 80 μm{sup 2} scanning area. The multifractal spectrum theory based on computational algorithms was applied for AFM data and multifractal spectra were calculated. The generalized dimension D{sub q} and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of dental nanocomposites polished by four different dental polishing protocols at nanometer scale. The results showed that the larger the spectrum width Δα (Δα = α{sub max} − α{sub min}) of the multifractal spectra f(α), the more non-uniform was the surface morphology. Also, the 3-D surface topography was described by statistical parameters, according to ISO 25178-2:2012. The 3-D surface of samples had a multifractal nature. Nanofilled composite had lower values of height parameters than nanohybrid composites, due to its composition. Multi-step polishing protocol

  15. Morphological and voltammetric characterization of different concentrations of spin coated Nafion-Ru(bpy)2+3 thin films

    International Nuclear Information System (INIS)

    Tuason, B S B; Tiong-Palisoc, S; Tiamzon-Natividad, M

    2015-01-01

    Different concentrations of Ru(bpy) 2+ 3 were successfully deposited on ITO coated glass substrates employing a simple method using a spin coater. The surface morphology was determined by scanning electron microscopy (SEM). The transport mechanism and the diffusion coefficient of the redox mediators within the films were characterized using cyclic voltammetry (CV). The concentrations were varied by dissolving different amounts of the redox mediator in methanol and 5% Nafion. SEM micrographs showed that the roughness of the surface increased with concentration of redox mediator. CV showed successful incorporation of Ru(bpy) 2+ 3 . The order of the magnitude of the diffusion coefficients confirmed that the redox mediators were immobilized within the Nafion thin film. The resulting amount of redox mediator immobilized can be manipulated by simply varying the concentration of the casting solution. (paper)

  16. Multipulse nanosecond laser irradiation of silicon for the investigation of surface morphology and photoelectric properties

    Science.gov (United States)

    Sardar, Maryam; Chen, Jun; Ullah, Zaka; Jelani, Mohsan; Tabassum, Aasma; Cheng, Ju; Sun, Yuxiang; Lu, Jian

    2017-12-01

    We irradiate the single crystal boron-doped silicon (Si) with different number of laser pulses at constant fluence (7.5 J cm-2) in ambient air using Nd:YAG laser and examine its surface morphology and photoelectric properties in details. The results obtained from optical micrographs reveal the increase in heat affected zone (HAZ) and melted area of laser irradiated Si with increasing number of laser pulses. The SEM micrographs evidence the formation of various surface morphologies like laser induced periodic surface structures, crater, microcracks, clusters, cavities, pores, trapped bubbles, nucleation sites, micro-bumps, redeposited material and micro- and nano-particles on the surface of irradiated Si. The surface profilometry analysis informs that the depth of crater is increased with increase in number of incident laser pulses. The spectroscopic ellipsometry reveals that the multipulse irradiation of Si changes its optical properties (refractive index and extinction coefficient). The current-voltage (I-V) characteristic curves of laser irradiated Si show that although the multipulse laser irradiation produces considerable number of surface defects and damages, the electrical properties of Si are well sustained after the multipulse irradiation. The current findings suggest that the multipulse irradiation can be an effective way to tune the optical properties of Si for the fabrication of wide range of optoelectronic devices.

  17. Surface morphology and electronic structure of halogen etched InAs (1 1 1)

    Energy Technology Data Exchange (ETDEWEB)

    Eassa, N., E-mail: nashwa.eassa@nmmu.ac.za [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Murape, D.M. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Betz, R. [Department of Chemistry, Nelson Mandela Metropolitan University (South Africa); Neethling, J.H.; Venter, A.; Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)

    2012-05-15

    The reaction of halogen-based etchants with n-InAs (1 1 1)A and the resulting surface morphology and surface electronic structure are investigated using field emission scanning electron microscopy and Raman spectroscopy. Using the intensity ratio of the unscreened longitudinal optical (LO) phonon to the transverse optical (TO) phonon in the Raman spectrum, a significant reduction in band bending is deduced after exposure of the InAs surface to HCl:H{sub 2}O, Br-methanol and I-ethanol for moderate times and concentrations. These procedures also lead to smooth and defect-free InAs surfaces. The improvements in surface properties are reversed, however, if the concentrations of the etchants are increased or the etch time is too long. In the worst cases, pit formation and inverted pyramids with {l_brace}1 1 1{r_brace} side facets are observed. The influence of the etchant concentration and etch time on the morphological and electronic properties of the etched surfaces is reported.

  18. Surface Roughness and Morphology Customization of Additive Manufactured Open Porous Ti6Al4V Structures

    Science.gov (United States)

    Pyka, Grzegorz; Kerckhofs, Greet; Papantoniou, Ioannis; Speirs, Mathew; Schrooten, Jan; Wevers, Martine

    2013-01-01

    Additive manufacturing (AM) is a production method that enables the building of porous structures with a controlled geometry. However, there is a limited control over the final surface of the product. Hence, complementary surface engineering strategies are needed. In this work, design of experiments (DoE) was used to customize post AM surface treatment for 3D selective laser melted Ti6Al4V open porous structures for bone tissue engineering. A two-level three-factor full factorial design was employed to assess the individual and interactive effects of the surface treatment duration and the concentration of the chemical etching solution on the final surface roughness and beam thickness of the treated porous structures. It was observed that the concentration of the surface treatment solution was the most important factor influencing roughness reduction. The designed beam thickness decreased the effectiveness of the surface treatment. In this case study, the optimized processing conditions for AM production and the post-AM surface treatment were defined based on the DoE output and were validated experimentally. This allowed the production of customized 3D porous structures with controlled surface roughness and overall morphological properties, which can assist in more controlled evaluation of the effect of surface roughness on various functional properties. PMID:28788357

  19. Surface Roughness and Morphology Customization of Additive Manufactured Open Porous Ti6Al4V Structures

    Directory of Open Access Journals (Sweden)

    Martine Wevers

    2013-10-01

    Full Text Available Additive manufacturing (AM is a production method that enables the building of porous structures with a controlled geometry. However, there is a limited control over the final surface of the product. Hence, complementary surface engineering strategies are needed. In this work, design of experiments (DoE was used to customize post AM surface treatment for 3D selective laser melted Ti6Al4V open porous structures for bone tissue engineering. A two-level three-factor full factorial design was employed to assess the individual and interactive effects of the surface treatment duration and the concentration of the chemical etching solution on the final surface roughness and beam thickness of the treated porous structures. It was observed that the concentration of the surface treatment solution was the most important factor influencing roughness reduction. The designed beam thickness decreased the effectiveness of the surface treatment. In this case study, the optimized processing conditions for AM production and the post-AM surface treatment were defined based on the DoE output and were validated experimentally. This allowed the production of customized 3D porous structures with controlled surface roughness and overall morphological properties, which can assist in more controlled evaluation of the effect of surface roughness on various functional properties.

  20. Synthesis, characterization, Hirshfeld surface and theoretical ...

    Indian Academy of Sciences (India)

    ALI HARCHANI

    2017-09-06

    Sep 6, 2017 ... model. The PM3 and PM6 semiempirical models were parameterized for most transition metals, and they usually provided good results.13 Hirshfeld surfaces computational analysis and associated 2D fingerprint plots14 were carried out using the Crystal Explorer 3.1 software15 and TONTO16 system. 3.

  1. Characterization of polychlorinated biphenyls in surface sediments ...

    African Journals Online (AJOL)

    The distribution and concentrations of 6 indicator polychlorinated biphenyl (PCB) congeners, nos. 28, 52, 101, 138, 153 and 180, were determined in surface sediments from the North End Lake in Port Elizabeth, South Africa. Forty-two surficial sediment samples were collected from different locations covering the region that ...

  2. Characterization of high surface area silicon oxynitrides

    International Nuclear Information System (INIS)

    Lednor, P.W.; DeRuiter, R.; Emeis, K.A.

    1992-01-01

    In heterogenous catalysis, liquid or gaseous feedstocks are converted over a solid catalyst into more desirable products. Such processes form an essential part of the oil and petrochemical industries. The solid catalyst usually consists of an inorganic phase, with or without metal particles on the surface. Examples include platinum particles on gamma alumina (a reforming catalyst used in oil processing), chromium particles on silica (an ethylene polymerization catalyst) and zeolites or amorphous silica-aluminas (used as solid acids).Oxides have been widely investigated in catalysis, and silica, alumina, and aluminosilicates find application commercially on a large scale. On the other hand, non-oxide materials such as nitrides, carbides and borides have been relatively little investigated. The main reason for this has been the lack of routes to the high surface area forms usually required in catalysis. However, this situation has changed significantly in recent years, due to the interest in high surface area non-oxides as precursors to fully dense ceramics; in this paper, the authors have reviewed synthetic routes to high surface area non-oxides

  3. Characterization of multifunctional surfaces during fabrication

    DEFF Research Database (Denmark)

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

    2011-01-01

    The multifunctional surfaces herein studied are intended for carrying high loads as well as providing lubrication. They are produced by hard turning, creating a periodic pattern that will constitute the lubricant channels, followed by accurate Robot Assisted Polishing to smooth the tops of the cu...

  4. Influence of Surface Morphology on the Antimicrobial Effect of Transition Metal Oxides in Polymer Surface.

    Science.gov (United States)

    Oh, Yoo Jin; Hubauer-Brenner, Michael; Hinterdorfer, Peter

    2015-10-01

    In this study, the physical properties of transition metal oxide surfaces were examined using scanning probe microscopic (SPM) techniques for elucidating the antimicrobial activity of molybdenum trioxide (MoO3), tungsten trioxide (WO3), and zinc oxide (ZnO) embedded into the polymers thermoplastic polyurethane (TPU) and polypropylene (PP). We utilized atomic force microscopy (AFM) in the contact imaging mode and its derivative single-pass Kelvin probe force microscopy for investigating samples that were presumably identical in their compositions, but showed different antimicrobial activity in bacterial adhesion tests. Our results revealed that surfaces with larger roughness and higher surface potential variation showed stronger antimicrobial activities compared to smoother and homogeneously charge-distributed surfaces. In addition, capacitance gradient (dC/dZ) measurements were performed to elucidate the antimicrobial activity arising from the different dielectric behavior of the transition metal oxides in this heterogeneous polymer surface. We found that the nano-scale exposure of transition metal oxides on polymer surfaces provided strong antimicrobial effects. Applications arising from our studies will be useful for public and healthcare environments.

  5. Morphological and molecular characterization of Gordius, a horse hairworm recovered from cricket

    Directory of Open Access Journals (Sweden)

    Gautam Patra

    2017-07-01

    Full Text Available Objective: To describe the morphological and molecular characterization of a newly isolated Gordius spp. from of the northeastern states of India. Methods: Identification of the parasite was based on light microscopy and scanning electron microscopy. For molecular identification a partial sequence of ITS2 region was amplified. The product was cloned in cloning vector and subsequently phylogenetic analysis was done. Results: Based on the morphological and molecular analysis, the nematode infesting cricket was confirmed to be Gordius species. Grossly the length of those nematodes ranged between 15.1 and 35.5 cm. The present study also described the light microscopy and fine structural morphological study of the isolated species. Molecular amplification targeting ITS2 region of Gordius was found to be approximately 1 048 bp. Phylogenetic analysis revealed that the Gordius species is a close relative (100% to Malaysian species. Conclusions: Occurrence of Gordius species in Indian cricket has been confirmed and found 100% similarity with Malaysian species.

  6. Modulation of structure, morphology and wettability of polytetrafluoroethylene surface by low energy ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Atta, Ali; Fawzy, Yasser H.A. [Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA) (Egypt); Bek, Alpan, E-mail: bek@metu.edu.tr [Physics Department, Middle East Technical University (METU), Ankara (Turkey); Abdel-Hamid, Hassan M. [Diagnostic Radiology Department, Applied Medical Sciences Faculty, Jazan University (Saudi Arabia); El-Oker, Mohamed M. [Physics Department, Faculty of Science, Al-Azhar University, Cairo (Egypt)

    2013-04-01

    Polytetrafluoroethylene (PTFE) films were irradiated under vacuum with 3 keV Argon ions (Ar{sup +}) and fluences ranging from 0.5 × 10{sup 18} to 2 × 10{sup 18} ions/cm{sup 2}. Ion induced PTFE surface modifications of structural, morphological and wettability nature were studied by means of Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, atomic force microscopy and force spectroscopy, and contact angle measurements. FTIR analysis indicated defluorination of PTFE due to the rupture of C–C and C–F bonds. The values of droplet contact angle of the irradiated samples decreased gradually with the increasing ion flux, and were found to be very sensitive to the environmental humidity under which the measurements were made. The experimental results show that the surface chemical bond, morphology, and wettability of irradiated PTFE samples depend closely on the argon ion flux.

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

    Science.gov (United States)

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

    2017-12-01

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

  8. Morphological analysis of the left ventricular endocardial surface using a bag-of-features descriptor.

    Science.gov (United States)

    Mukhopadhyay, Anirban; Qian, Zhen; Bhandarkar, Suchendra M; Liu, Tianming; Voros, Szilard; Rinehart, Sarah

    2015-07-01

    The limitations of conventional imaging techniques have hitherto precluded a thorough and formal investigation of the complex morphology of the left ventricular (LV) endocardial surface and its relation to the severity of coronary artery disease (CAD). However, recent developments in high-resolution multirow-detector computed tomography (MDCT) scanner technology have enabled the imaging of the complex LV endocardial surface morphology in a single heartbeat. Analysis of high-resolution computed tomography images from a 320-MDCT scanner allows for the noninvasive study of the relationship between the percent diameter stenosis (DS) values of the major coronary arteries and localization of the cardiac segments affected by coronary arterial stenosis. In this paper, a novel approach for the analysis of the nonrigid LV endocardial surface from MDCT images, using a combination of rigid body transformation-invariant shape descriptors and a more generalized isometry-invariant Bag-of-Features descriptor, is proposed and implemented. The proposed approach is shown to be successful in identifying, localizing, and quantifying the incidence and extent of CAD and, thus, is seen to have a potentially significant clinical impact. Specifically, the association between the incidence and extent of CAD, determined via the percent DS measurements of the major coronary arteries, and the alterations in the endocardial surface morphology is formally quantified. The results of the proposed approach on 16 normal datasets and 16 abnormal datasets exhibiting CAD with varying levels of severity are presented. A multivariable regression test is employed to test the effectiveness of the proposed morphological analysis approach. Experiments performed on a strictly leave-one-out basis are shown to exhibit a distinct and interesting pattern in terms of the correlation coefficient values within the cardiac segments, where the incidence of coronary arterial stenosis is localized.

  9. Secretin-stimulated MRI characterization of pancreatic morphology and function in patients with chronic pancreatitis.

    Science.gov (United States)

    Madzak, Adnan; Olesen, Søren Schou; Haldorsen, Ingfrid Salvesen; Drewes, Asbjørn Mohr; Frøkjær, Jens Brøndum

    Chronic pancreatitis (CP) is characterized by abnormal pancreatic morphology and impaired endocrine and exocrine function. However, little is known about the relationship between pancreatic morphology and function, and also the association with the etiology and clinical manifestations of CP. The aim was to explore pancreatic morphology and function with advanced MRI in patients with CP and healthy controls (HC) METHODS: Eighty-two patients with CP and 22 HC were enrolled in the study. Morphological imaging parameters included pancreatic main duct diameter, gland volume, fat signal fraction and apparent diffusion coefficient (ADC) values. Functional secretin-stimulated MRI (s-MRI) parameters included pancreatic secretion (bowel fluid volume) and changes in pancreatic ADC value before and after secretin stimulation. Patients were classified according to the modified Cambridge and M-ANNHEIM classification system and fecal elastase was collected. All imaging parameters differentiated CP patients from HC; however, correlations between morphological and functional parameters in CP were weak. Patients with alcoholic and non-alcoholic etiology had comparable s-MRI findings. Fecal elastase was positively correlated to pancreatic gland volume (r = 0.68, P = 0.0016) and negatively correlated to Cambridge classification (r = -0.35, P gland volume was negatively correlated to the duration of CP (r = -0.39, P gland volume was significantly decreased in the severe stages of CP (P = 0.001). S-MRI provides detailed information about pancreatic morphology and function and represents a promising non-invasive imaging method to characterize pancreatic pathophysiology and may enable monitoring of disease progression in patients with CP. Copyright © 2017 IAP and EPC. Published by Elsevier B.V. All rights reserved.

  10. Superhydrophobic Surfaces Developed by Mimicking Hierarchical Surface Morphology of Lotus Leaf

    Directory of Open Access Journals (Sweden)

    Sanjay S. Latthe

    2014-04-01

    Full Text Available The lotus plant is recognized as a ‘King plant’ among all the natural water repellent plants due to its excellent non-wettability. The superhydrophobic surfaces exhibiting the famous ‘Lotus Effect’, along with extremely high water contact angle (>150° and low sliding angle (<10°, have been broadly investigated and extensively applied on variety of substrates for potential self-cleaning and anti-corrosive applications. Since 1997, especially after the exploration of the surface micro/nanostructure and chemical composition of the lotus leaves by the two German botanists Barthlott and Neinhuis, many kinds of superhydrophobic surfaces mimicking the lotus leaf-like structure have been widely reported in the literature. This review article briefly describes the different wetting properties of the natural superhydrophobic lotus leaves and also provides a comprehensive state-of-the-art discussion on the extensive research carried out in the field of artificial superhydrophobic surfaces which are developed by mimicking the lotus leaf-like dual scale micro/nanostructure. This review article could be beneficial for both novice researchers in this area as well as the scientists who are currently working on non-wettable, superhydrophobic surfaces.

  11. Biofilm formation and Candida albicans morphology on the surface of denture base materials.

    Science.gov (United States)

    Susewind, Sabine; Lang, Reinhold; Hahnel, Sebastian

    2015-12-01

    Fungal biofilms may contribute to the occurrence of denture stomatitis. The objective of the study was to investigate the biofilm formation and morphology of Candida albicans in biofilms on the surface of denture base materials. Specimens were prepared from different denture base materials. After determination of surface properties and salivary pellicle formation, mono- and multispecies biofilm formation including Candida albicans ATCC 10231 was initiated. Relative amounts of adherent cells were determined after 20, 44, 68 and 188 h; C. albicans morphology was analysed employing selective fluorescence microscopic analysis. Significant differences were identified in the relative amount of cells adherent to the denture base materials. Highest blastospore/hyphae index suggesting an increased percentage of hyphae was observed in mono- and multispecies biofilms on the soft denture liner, which did not necessarily respond to the highest relative amount of adherent cells. For both biofilm models, lowest relative amount of adherent cells was identified on the methacrylate-based denture base material, which did not necessarily relate to a significantly lower blastospore/hyphae index. The results indicate that there are significant differences in both biofilm formation as well as the morphology of C. albicans cells in biofilms on the surface of different denture base materials. © 2015 Blackwell Verlag GmbH.

  12. Effect of interface on surface morphology and proton conduction of polymer electrolyte thin films.

    Science.gov (United States)

    Ohira, Akihiro; Kuroda, Seiichi; Mohamed, Hamdy F M; Tavernier, Bruno

    2013-07-21

    To understand the relationship between surface morphology and proton conduction of polymer electrolyte thin films, perfluorinated ionomer Nafion® thin films were prepared on different substrates such as glassy carbon (GC), hydrophilic-GC (H-GC), and platinum (Pt) as models for the ionomer film within a catalyst layer. Atomic force microscopy coupled with an electrochemical (e-AFM) technique revealed that proton conduction decreased with film thickness; an abrupt decrease in proton conductance was observed when the film thickness was less than ca. 10 nm on GC substrates in addition to a significant change in surface morphology. Furthermore, thin films prepared on H-GC substrates with UV-ozone treatment exhibited higher proton conduction than those on untreated GC substrates. However, Pt substrates exhibited proton conduction comparable to that of GCs for films thicker than 20 nm; a decrease in proton conduction was observed at ∼5 nm thick film but was still much higher than for carbon substrates. These results indicate that the number of active proton-conductive pathways and/or the connectivity of the proton path network changed with film thickness. The surface morphology of thinner films was significantly affected by the film/substrate interface and was fundamentally different from that of the bulk thick membrane.

  13. Formation and surface characterization of nanostructured Al2O3 ...

    Indian Academy of Sciences (India)

    Administrator

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

  14. Morphologic characterization and quantitative analysis on in vitro bacteria by nuclear techniques of measurement

    International Nuclear Information System (INIS)

    Lopes, Joana D'Arc Ramos

    2001-10-01

    The great difficulty to identify microorganisms (bacteria) from infectious processes is related to the necessary time to obtain a reliable result, about 72 hours. The purpose of this work is to establish a faster method to characterize bacterial morphologies through the use of neutron radiography, which can take about 5 hours. The samples containing the microorganisms, bacteria with different morphologies, after the appropriate microbiologic procedures were incubated with B 10 for 30 minutes and soon after deposited in a plate of a solid detector of nuclear tracks (SSNTD), denominated CR-39. To obtain the images relative to bacteria, the detector was submitted to the flow of thermal neutrons of the order of 2.2 x 10 5 n/cm 2 .s from the J-9 channel of the Reactor Argonauta (IEN/CNEN). To observe the images from bacteria in each sample under an optical microscope, the sheets were chemically developed. The analysis of the images revealed morphologic differences among the genera (Gram positive from Gram-negative and coccus from bacillus), in samples containing either isolated or mixed bacteria. We thus verified the viability of the technique to achieve morphological characterization of different microorganisms. A quantitative approach seemed also to be feasible with the technique. The whole process took about 2 hours. (author)

  15. Multitechnique characterization of CPTi surfaces after electro discharge machining (EDM).

    Science.gov (United States)

    Zinelis, Spiros; Al Jabbari, Youssef S; Thomas, Andrew; Silikas, Nick; Eliades, George

    2014-01-01

    The aim of this study was to comparatively assess the surface roughness parameters, the hardness, and the elemental and molecular alterations induced on CPTi surfaces after conventional finishing and finishing with electro discharge machining (EDM). A completed cast model of an arch that received four implants was used for the preparation of two grade II CPTi castings. One framework was conventionally finished (CF), whereas the other was subjected to EDM finishing. The surface morphology was imaged employing SEM. 3D surface parameters (S a, S q, S z, S ds, S dr, and S ci) were calculated by optical profilometry. The elemental composition of the treated surfaces was determined by energy dispersive X-ray analysis, whereas the elemental and chemical states of the outmost layer were investigated by X-ray photoelectron spectrometry. Surface hardness was also tested with a Knoop indenter. The results of surface roughness parameters, elemental analysis, and hardness were compared using unpaired t test (a = 0.05). The EDM group demonstrated a rougher surface, with a significant uptake of C and Cu. The CF surface mainly consisted of TiO2. On EDM surface though, Ti was probed in different chemicals states (TiO2, Ti2O3, TiC and metallic Ti) and Cu was traced as Cu2O and CuO. Hardness after EDM was almost ten times higher than CF. EDM significantly affected surface roughness, chemical state, and hardness properties of grade II CPTi castings in comparison with CF. The morphological and elemental alterations of EDM-treated CPTi surfaces may strongly contribute to the reduced corrosion resistance documented for this procedure. The degradation of electrochemical properties may have further biological implications through ionic release in the oral environment.

  16. CHARACTERIZATION OF MORPHOLOGICAL TRAITS OF COMMERCIAL INTEREST IN THE MORELET'S CROCODILE (Crocodylus moreletii

    Directory of Open Access Journals (Sweden)

    Ricardo Serna-Lagunes

    2011-11-01

    Full Text Available Crocodylus moreletii is a species of commercial interest based on its skin. In this study, five morphological traits of commercial interest were characterized in 125 captivity-raised specimens of C. moreletii from four populations (Puente Chilapa, Gutiérrez Zamora, Villa Juárez and Puerto Vallarta. A canonical discriminant analysis (CDA was used to differentiate the populations according to their morphological traits, a cluster analysis (CA was used to infer which populations had the largest total length (TL, and a covariance analysis (ANCOVA was used to assess the allometry and detect which population was different in terms of TL. The CDA showed no significant effects, suggesting that the morphological traits were similar among populations; the CA grouped two populations which had the largest body size; the ANCOVA revealed a significant correlation between morphological traits and detected a TL effect significantly lower in males and females from Puente Chilapa, in comparison with the other three populations. In conclusion, the males from Gutiérrez Zamora and the females from Villa Juárez were morphologically outstanding in terms of TL, and they would be the right crocodiles to establish a breeding nucleus in order to obtain offspring with their phenotypic characteristics.

  17. Superhydrophobic Polyimide via Ultraviolet Photooxidation: The Evolution of Surface Morphology and Hydrophobicity under Different Ultraviolet Intensities

    Directory of Open Access Journals (Sweden)

    Hongyu Gu

    2015-01-01

    Full Text Available Ultraviolet (UV photooxidation has recently been developed to fabricate superhydrophobic polyimide (PI films in combination with fluoroalkylsilane modification. However, it remains unclear whether the surface morphology and hydrophobicity are sensitive to technical parameters such as UV intensity and radiation environment. Herein, we focus on the effects of UV intensity on PI surface structure and wettability to gain comprehensive understanding and more effective control of this technology. Scanning electron microscopy (SEM and atomic force microscopy (AFM results showed that UV intensity governed the evolutionary pattern of surface morphology: lower UV intensity (5 mW/cm2 facilitated in-plane expansion of dendritic protrusions while stronger UV (10 and 15 mW/cm2 encouraged localized growth of protrusions in a piling-up manner. Surface roughness and hydrophobicity maximized at the intensity of 10 mW/cm2, as a consequence of the slowed horizontal expansion and preferred vertical growth of the protrusions when UV intensity increased. Based on these results, the mechanism that surface micro/nanostructures developed in distinct ways when exposed to different UV intensities was proposed. Though superhydrophobicity (water contact angle larger than 150° can be achieved at UV intensity not less than 10 mW/cm2, higher intensity decreased the effectiveness. Therefore, the UV photooxidation under 10 mW/cm2 for 72 h is recommended to fabricate superhydrophobic PI films.

  18. Coevolution of bed surface patchiness and channel morphology: 2. Numerical experiments

    Science.gov (United States)

    Nelson, Peter A.; McDonald, Richard R.; Nelson, Jonathan M.; Dietrich, William E.

    2015-01-01

    In gravel bed rivers, bed topography and the bed surface grain size distribution evolve simultaneously, but it is not clear how feedbacks between topography and grain sorting affect channel morphology. In this, the second of a pair of papers examining interactions between bed topography and bed surface sorting in gravel bed rivers, we use a two-dimensional morphodynamic model to perform numerical experiments designed to explore the coevolution of both free and forced bars and bed surface patches. Model runs were carried out on a computational grid simulating a 200 m long, 2.75 m wide, straight, rectangular channel, with an initially flat bed at a slope of 0.0137. Over five numerical experiments, we varied (a) whether an obstruction was present, (b) whether the sediment was a gravel mixture or a single size, and (c) whether the bed surface grain size feeds back on the hydraulic roughness field. Experiments with channel obstructions developed a train of alternate bars that became stationary and were connected to the obstruction. Freely migrating alternate bars formed in the experiments without channel obstructions. Simulations incorporating roughness feedbacks between the bed surface and flow field produced flatter, broader, and longer bars than simulations using constant roughness or uniform sediment. Our findings suggest that patches are not simply a by-product of bed topography, but they interact with the evolving bed and influence morphologic evolution.

  19. Surface-spin magnetism of antiferromagnetic NiO in nanoparticle and bulk morphology

    International Nuclear Information System (INIS)

    Jagodic, M; Jaglicic, Z; Jelen, A; Dolinsek, J; Lee, Jin Bae; Kim, Hae Jin; Kim, Young-Min

    2009-01-01

    The surface-spin magnetism of the antiferromagnetic (AFM) material NiO in nanoparticle and bulk morphology was investigated by magnetic measurements (temperature-dependent zero-field-cooled (zfc) and field-cooled (fc) dc susceptibility, ac susceptibility and zfc and fc hysteresis loops). We addressed the question of whether the multisublattice ordering of the uncompensated surface spins and the exchange bias (EB) effect are only present in the nanoparticles, originating from their high surface-to-volume ratio or if these surface phenomena are generally present in the AFM materials regardless of their bulky or nanoparticle morphology, but the effect is just too small to be detected experimentally in the bulk due to a very small surface magnetization. Performing experiments on the NiO nanoparticles of different sizes and bulk NiO grains, we show that coercivity enhancement and hysteresis loop shift in the fc experiments, considered to be the key experimental manifestations of multisublattice ordering and the EB effect, are true nanoscale phenomena only present in the nanoparticles and absent in the bulk.

  20. Effects of erosive challenge on the morphology and surface properties of luting cements

    Directory of Open Access Journals (Sweden)

    Brenna Louise Cavalcanti GONDIM

    Full Text Available Abstract Introduction Few studies investigated the surface properties of luting cements after erosive challenge. Objective To evaluate the surface roughness (Ra, Vickers hardness (VHN and morphology of 4 luting cements after erosive challenge. Material and method Twenty specimens of each cement were prepared (4×2mm and divided into experimental (erosive challenge and control (artificial saliva groups (n=10: Rely X U200 (U200; Rely X ARC (ARC; Ketac Cem Easy Mix (Ketac and Zinc phosphate (ZnP. The erosive challenge was performed by four daily erosive cycles (90s in a cola drink and 2 h in artificial saliva over 7 days. Ra and VHN readings were performed before and after erosion. The percentage of hardness loss (%VHN was obtained after erosion. The surface morphology was analyzed by scanning electron microscopy (SEM. ANOVA, Tukey and Student-T tests were used (α=0.05. Result After erosion, all luting cements had increase in Ra values and U200 and ZnP groups had the highest %VHN. After saliva immersion, only U200 and ZnP groups had significant increases in Ra values and there were no significant differences among the groups in %VHN. SEM analysis showed that Ketac and ZnP groups had rough and porous surfaces, and U200 group had higher resin matrix degradation than ARC group. Conclusion Erosive challenge with a cola drink affected the surface properties of all luting cements.

  1. Surface Sensitive Techniques for Advanced Characterization of Luminescent Materials

    OpenAIRE

    Hendrik C. Swart

    2017-01-01

    The important role of surface sensitive characterization techniques such as Auger electron spectroscopy (AES), X-ray photo electron spectroscopy (XPS), time of flight scanning ion mass spectrometry (TOF-SIMS) and High resolution transmission electron microscopy (HRTEM) for the characterization of different phosphor materials is discussed in this short review by giving selective examples from previous obtained results. AES is used to monitor surface reactions during electron bombardment and al...

  2. The surface morphology of retinal breaks and lattice retinal degeneration. A scanning electron microscopic study.

    Science.gov (United States)

    Robinson, M R; Streeten, B W

    1986-02-01

    In 14 of 110 eye bank eyes, lesions characteristic of peripheral retinal surface pathology were examined by scanning electron microscopy (SEM). These included operculated and flap tears, trophic round holes, lattice degeneration with holes, and paravascular retinal "pitting" degeneration. By SEM, the edges of the retinal breaks were covered by smooth cellular membranes, merging peripherally with a meshwork of vitreous fibrils. The membrane cells had poorly defined borders, a pitted surface, and variable numbers of microvilli consistent with glia. Lattice surfaces and foci of paravascular retinal degeneration were covered by similar membrane, but showed characteristic differences. It appears that breaks in the internal limiting membrane always stimulate proliferation of preretinal glial membranes. Similar cellular morphology of the membranes associated with breaks is consistent with a common cell of origin. Limited proliferation of these membranes suggests that surface gliosis is normally inhibited when the cells contact either intact basement membrane or vitreous.

  3. Pattern recognition characterizations of micromechanical and morphological materials states via analytical quantitative ultrasonics

    Science.gov (United States)

    Williams, J. H., Jr.; Lee, S. S.

    1986-01-01

    One potential approach to the quantitative acquisition of discriminatory information that can isolate a single structural state is pattern recognition. The pattern recognition characterizations of micromechanical and morphological materials states via analytical quantiative ultrasonics are outlined. The concepts, terminology, and techniques of statistical pattern recognition are reviewed. Feature extraction and classification and states of the structure can be determined via a program of ultrasonic data generation.

  4. Simultaneous Morphological and Molecular Characterization of Tatera indica in Southwestern Iran

    OpenAIRE

    Mohammadi, Somayeh; Parvizi, Parviz

    2015-01-01

    Background: Interest in Tatera indica rodent arises mostly because it is believed that this species is survived among four subspecies reported from Iran, two of which exist in Khuzestan Province. In addition, it might has a role as res­ervoir hosts of zoonotic cutaneous leishmaniasis in the transmission of Leishmania major in some of the widespread Asian foci including southwestern Iran.Methods: Diagnostic morphological and molecular markers for T. indica were sought by characterizing from in...

  5. Characterization of Stachybotrys from water-damaged buildings based on morphology, growth, and metabolite production

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Nielsen, Kristian Fog; Jarvis, Bruce

    2002-01-01

    was a Macrocyclic trichothecene-producer. The second undescribed taxon produced atranones and could be differentiated from S. chartarum by its growth characteristics arid pigment production. Our results correlate with different inflammatory and toxicological properties reported for these same isolates and show......, but inconsistent toxicity results arid taxonomic confusion prompted the present study. In this study, 122 Stachybotrys isolates, mainly from,water-damaged buildings, were characterized arid identified by combining three different approaches: morphology. colony characteristics, arid metabolite production. Two...

  6. Phylogenetic Placement and Morphological Characterization of Sclerotium rolfsii (Teleomorph: Athelia rolfsii) Associated with Blight Disease of Ipomoea batatas in Korea.

    Science.gov (United States)

    Paul, Narayan Chandra; Hwang, Eom-Ji; Nam, Sang-Sik; Lee, Hyeong-Un; Lee, Joon-Seol; Yu, Gyeong-Dan; Kang, Yong-Gu; Lee, Kyeong-Bo; Go, San; Yang, Jung-Wook

    2017-09-01

    In this study, we aimed to characterize fungal samples from necrotic lesions on collar regions observed in different sweetpotato growing regions during 2015 and 2016 in Korea. Sclerotia appeared on the root zone soil surface, and white dense mycelia were observed. At the later stages of infection, mother roots quickly rotted, and large areas of the plants were destroyed. The disease occurrence was monitored at 45 and 84 farms, and 11.8% and 6.8% of the land areas were found to be infected in 2015 and 2016, respectively. Fungi were isolated from disease samples, and 36 strains were preserved. Based on the cultural and morphological characteristics of colonies, the isolates resembled the reference strain of Sclerotium rolfsii . Representative strains were identified as S. rolfsii (teleomorph: Athelia rolfsii ) based on phylogenetic analysis of the internal transcribed spacer and large subunit genes along with morphological observations. To test the pathogenicity, sweetpotato storage roots were inoculated with different S. rolfsii strains. 'Yulmi' variety displayed the highest disease incidence, whereas 'Pungwonmi' resulted in the least. These findings suggested that morphological characteristics and molecular phylogenetic analysis were useful for identification of S. rolfsii .

  7. Surface Morphology and Overlayer Formation Kinetics of OXYGEN/SILVER(110) Studied by Scanning Tunneling Microscopy

    Science.gov (United States)

    Pai, Woei Wu.

    1995-01-01

    I have applied scanning tunneling microscopy (STM) to study clean and oxygen-covered vicinal Ag(110) surfaces at room temperature. Experimental results of surface morphology/stability, surface mass transport and surface chemical reactivity are presented. On clean vicinal Ag(110) surfaces, the steps distribute under the influence of step-step interactions. The terrace width distributions indicate an additional oscillatory component besides an l^{-2} interaction term. If the surface is contaminated slightly (quasi-clean), isolated "pinning sites" impede the motion of steps. The interactions between steps push the steps across the pinning site, resulting in a curved step front. When oxygen atoms adsorb on stepped Ag(110), a dramatic change in surface morphology occurs. The surface separates into two distinct phases--step bunches and large terraces (facets). The orientational instability is closely related to the linear "added-row" structure of the oxygen overlayer, as the long O chains push steps into bunches. The O chains do not push the steps effectively when O chains orient perpendicular to steps, and the faceting proceeds through nucleation. If the O chains orient near parallel to steps, however, O chains push the steps easily and the faceting proceeds through spinodal decomposition. To understand the mass transport during faceting, I quantify the thermal step fluctuations by employing a Langevin statistical analysis. The mass transport mechanism at the step edge is shown to be by atomic exchange between steps and terraces, making the step an effective source or sink for Ag adatoms. This Ag source also proves essential in O overlayer formation, since both Ag and O atoms are incorporated into the "added -row" overlayer structure. Because an Ag source must be found during the adlayer formation, I show the surface morphology is sensitive to oxygen dosing pressure. Above a critical O pressure of 10^{-5} mbar, vacancy islands on terraces provide a second source of Ag

  8. Surface Characterization and Cell Adhesion of Different Zirconia Treatments: An in vitro Study.

    Science.gov (United States)

    Nassif, Wadih; Rifai, Mohamad

    2018-02-01

    The aim of this study was to characterize the surface of zirconia subjected to different treatments and evaluate its effect on cell adhesion and proliferation. A total of 80 zirconia disks were divided into four groups (n = 20) according to the surface treatments used: group I: as-sintered (AS), no surface treatment applied; group II: abrasion treatment applied using Rocatec (ROC; 3M ESPE) system with silica-coated alumina powder of grit size 110 μm; group III: erbium, chromium:yttrium, scandium, gallium, garnet (Er, Cr:YSGG) laser (LAS; BIOLASE) was used at a frequency of 20 Hz and output power of 3 W; and group IV: specimens were subjected to the selective infiltration etching (SIE) technique. Surface characterization was evaluated for the different groups (roughness, hardness, and morphology), and cell behavior (adhesion and proliferation) was tested (a = 0.05). The ROC group reported a significant increase in surface roughness (2.201 ± 0.352) and Vickers hardness (1758 ± 16.6) compared with the other surface treatments. The SIE surface-treated group reported a significantly higher number of cells (64.5 ± 2.6 and 53.5 ± 2.2 respectively) compared with the other surface-treated groups. The SIE is a promising surface treatment for zirconia that significantly enhances cell adhesion and osseointegration. The SIE treatment of zirconia implants may help in a faster and better osseointegration.

  9. Chemical analysis and surface morphology of enamel following ozone application with different concentrations and exposure times

    Directory of Open Access Journals (Sweden)

    Iman I. Elsayad

    2011-04-01

    Full Text Available This study aimed to determine the effect of different ozone concentrations applied with different exposure times on the chemical composition and the surface morphology of enamel. Twenty human mandibular molars were divided into four groups according to ozone concentration and exposure times. Group A received 90 μg of ozone/ml oxygen for 1 min, group B received 90 μg of ozone/ml oxygen for 2 min, group C received 120 μg of ozone/ml oxygen for 1 min and group D received 120 μg of ozone/ml oxygen for 2 min. The ozone source was from a medical ozone generator equipped with a device to adjust the concentration. Buccal surfaces of teeth were tested before and after ozone application so that each tooth served as a control for itself, using Environmental Scanning Electron Microscope (ESEM connected to an Electron Dispersive Analytical X-ray (EDAX. Changes in calcium and phosphorus percentage levels were recorded and the Ca/P ratio was calculated. The values were statistically analyzed using the one-way ANOVA test with a level of significance set at P ⩽ 0.05. No statistical significant difference was found between the control and the tested groups in minerals content or ratio as P > 0.05. ESEM images showed enamel surface roughness with 2 min ozone exposure times. High ozone concentration with prolonged exposure time does not change the chemical composition of enamel. Applying ozone for 2 min alters the surface morphology of enamel causing variable degrees of roughness. Using high ozone concentrations with prolonged exposure times for caries reversal or prevention and for bleaching may be contraindicated if this changes the surface morphology of enamel.

  10. Influence of surface remodelling using burs on the macro and micro surface morphology of anatomically formed fibre posts.

    Science.gov (United States)

    Plotino, G; Grande, N M; Pameijer, C H; Somma, F

    2008-04-01

    To evaluate the effect of modifying preformed fibre-reinforced composite (FRC) endodontic posts on their surface morphology and to determine how this procedure affects the integrity of the posts. Surfaces of 10 preformed glass-fibre posts (group 1) and carbon-fibre posts (group 2) were compared with those of individually formed glass-fibre posts (group 3). Ten FRC posts were modelled in order to give them a shape as close as possible to the anatomy of oval root canals. Starting from a preformed cylindrical fibre post 2.5 mm in diameter, it was modelled in such a way as to passively occupy the entire post-space length, using a cast previously created as a guide. Microscopic analyses (optical stereomicroscope and scanning electron microscope) of the post surfaces revealed similar features in all three groups. All posts had regular surfaces after cutting with a diamond bur. Smear layer mainly attributable to the cutting procedures covered the cut surface of some specimens. In conclusion, modulation of a fibre post using a diamond-coated bur did not show a loss of integrity of the post. *Because of the importance of micromechanical retention, the surface integrity of fibre posts may be important for adhesion between post and composite resin. *Modification of a fibre post using a diamond-coated bur did not damage the surface integrity of the posts. *Fibre posts can be ground to a different shape without losing their surface integrity, resulting in posts with a surface that is not visibly different from unmodified commercially available fibre posts.

  11. Synthesis, surface characterization and optical properties of 3 ...

    Indian Academy of Sciences (India)

    3-Thiopropionic acid (TPA) capped ZnS:Cu nanocrystals have been successfully synthesized by simple aqueous method. Powder X-ray diffraction (XRD) studies revealed the particle size to be 4.2 nm. Surface characterization of the nanocrystals by FTIR spectroscopy has been done and the structure for surface bound TPA ...

  12. Synthesis, surface characterization and optical properties of 3

    Indian Academy of Sciences (India)

    3-Thiopropionic acid (TPA) capped ZnS:Cu nanocrystals have been successfully synthesized by simple aqueous method. Powder X-ray diffraction (XRD) studies revealed the particle size to be 4.2 nm. Surface characterization of the nanocrystals by FTIR spectroscopy has been done and the structure for surface bound TPA ...

  13. Topographic characterization of nanostructures on curved polymer surfaces

    DEFF Research Database (Denmark)

    Feidenhans'l, Nikolaj Agentoft; Petersen, Jan C.; Taboryski, Rafael J.

    2014-01-01

    method with a portable instrument that can be used in a production environment, and topographically characterize nanometer-scale surface structures on both flat and curved surfaces. To facilitate the commercialization of injection moulded polymer parts featuring nanostructures, it is pivotal...

  14. Characterization of silicon carbide and nitride powder surfaces

    International Nuclear Information System (INIS)

    Rahaman, M.N.; Boiteux, Y.; DeLohgne, L.C.

    1985-01-01

    The surfaces of SiC and Si 3 N 4 powders have been characterized using high resolution TEM, XPS and SIMS techniques. XPS is shown to be a powerful technique once a valid means of referencing the peaks is found. Attempts to manipulate the silica layer and its effect on surface properties are discussed

  15. Experimental characterization of micromilled surfaces by large range AFM

    DEFF Research Database (Denmark)

    Bariani, Paolo; Bissacco, Giuliano; Hansen, Hans Nørgaard

    2004-01-01

    of workpiece material, particularly when sub-micrometer chip thicknesses are considered and when machining hard materials. Quantification of surface topography is of fundamental importance for the evaluation of the generated surface; high resolution and wide measuring range being highly desirable...... for the evaluation of the distinctive behaviour of the ball end mill. The combination of the two demands is to date not matched by any measuring instrument. The paper describes an experimental investigation of surface topography of such micromachined surfaces. Accurate characterization of fine surface details...

  16. Synthesis and Characterization of Surface Functionalized Nanobiocomposite by Nano Hydroxyapatite

    OpenAIRE

    M. Meskinfam; M. S. Sadjadi; H. Jazdarreh

    2012-01-01

    In this study, synthesis of biomemitic patterned nano hydroxyapatite-starch biocomposites using different concentration of starch to evaluate effect of polymer alteration on biocomposites structural properties has been reported. Formation of hydroxyapatite nano particles was confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Size and morphology of the samples were characterized using scanning and transmission electron microscopy (SEM...

  17. Morphological and Molecular Characterization of Bova Olive Cultivar and Aroma Fingerprint of Its Oil

    Directory of Open Access Journals (Sweden)

    Marin Krapac

    2014-01-01

    Full Text Available This interdisciplinary study aims to contribute to the characterization of Istrian (Croatia olive cultivars and oil, giving for the first time the morphological and genetic profile of Bova cultivar, and chemical and sensorial characteristics of its oil. Morphological features of Bova cv. were determined according to the International Olive Council methodology, while molecular characterization was performed using eleven microsatellite markers. Bova cultivar was morphologically and genetically different from other described Istrian olive cultivars. The microsatellite profile of Bova was also unique when compared to more than 200 different Italian genotypes using the same set of markers. In order to characterize the oil from Bova cv., fruits from three trees at the same ripening stage were harvested and processed separately under the same conditions. Volatile composition of the obtained oil samples was determined using solid-phase microextraction with gas chromatography/mass spectrometry. About 50 volatiles were detected, mostly hydrocarbons (34.69 % of total peak area, followed by aldehydes (25.80 %, alcohols (22.24 %, ketones (8.76 %, organic acids (4.08 %, terpenes (2.10 %, esters (2.18 % and furans (0.26 %. Bova oil was rich in total C6 (39.87 % and C5 volatiles (13.85 %, biogenerated through the lipoxygenase pathway. The most prevalent volatile compound was C6 aldehyde E-2-hexenal. Quantitative descriptive sensory analysis of the investigated olive oil samples was carried out by a sensory panel. The sensory profile was characterized by medium intensities of olive fruity, green leaves and grass, light tomato and aromatic herbs flavours with mild apple and other ripe fruit notes. The taste was characterized by medium to strong bitterness, followed by medium pungency and mild sweetness.

  18. In-situ spectroscopic erosion yield measurement with applications to sputtering and surface morphology alterations

    International Nuclear Information System (INIS)

    Leung, W.K.; Hirooka, Y.; Conn, R.W.; Goebel, D.M.; Labombard, B.; Nygren, R.

    1988-01-01

    An in-situ spectroscopic erosion yield measurement is developed and used to monitor material surface erosion during bombardment by a plasma. The experiments are performed in a plasma that has the characteristics of a fusion tokamak boundary plasma but the technique is applicable to many processes where plasma erosion is important. Erosion yield of materials bombarded in a high flux (up to 10 18 ion/cm 2 /s) plasma environment has been previously studies using weight loss measurements. In the present study, the sputtered flux from a material is monitored by the line emission intensities of atoms eroded from the surface. The line intensities can be used to infer erosion yields after proper calibration. The method agrees well with results from weight loss measurements. Earlier work established that the material surface structure can substantially influence the erosion yield. When a change of surface morphology (e.g., cone formation) occurs, weight loss methods cannot be used to determine the erosion yield. However, the in-situ erosion measurement is suitable and is used to investigate the relation between the on-set of morphology changes and alternations in erosion yield during plasma bombardment. Experiments are reported for copper, as an example of a pure material, and stainless steel, as an example of an alloy system. The formation of surface cones is observed only when both the sample temperature is above a critical value and surface impurities exist. If the source of impurities is removed, or the sample temperature is lowered below the critical value, a surface rough with cones will be returned to a smooth state

  19. An in-situ spectroscopic erosion yield measurement with applications to sputtering and surface morphology alterations

    International Nuclear Information System (INIS)

    Leung, W.K.; Hirooka, Y.; Conn, R.W.; Goebel, D.M.; LaBombard, B.; Nygren, R.

    1988-07-01

    An in-situ spectroscopic erosion yield measurement is developed and used to monitor material surface erosion during bombardment by a plasma. The experiments are performed in a plasma that has the characteristics of a fusion tokamak boundary plasma but the technique is applicable to many processes where plasma erosion is important. Erosion yield of materials bombarded in a high flux (up to 10 18 ion/cm 2 /s) plasma environment has been previously studied using weight loss measurements. In the present study, the sputtered flux from a material is monitored by the line emission intensities of atoms eroded from the surface. The line intensities can be used to infer erosion yields after proper calibration. The method agrees well with results from weight loss measurements. Earlier work established that the material surface structure can substantially influence the erosion yield. When a change of surface morphology (e.g. cone formation) occurs, weight loss methods cannot be used to determine the erosion yield. However, the in-situ erosion measurement is suitable and is used to investigate the relation between the on-set of morphology changes and alternations in erosion yield during plasma bombardment. Experiments are reported for copper, as an example of pure material, and stainless steel, as a example of an alloy system. The formation of surface cones is observed only when both the sample temperature is above a critical value and surface impurities exist. If the source of impurities is removed, or the sample temperature is lowered below the critical values, a surface rough with cones will be returned to smooth state. 20 refs., 10 figs

  20. In situ spectroscopic erosion yield measurement with applications to sputtering and surface morphology alterations

    International Nuclear Information System (INIS)

    Leung, W.K.; Hirooka, Y.; Conn, R.W.; Goebel, D.M.; Labombard, B.; Nygren, R.

    1989-01-01

    An in situ spectroscopic erosion yield measurement is developed and used to monitor material surface erosion during bombardment by a plasma. The experiments are performed in a plasma that has the characteristics of a fusion tokamak boundary plasma but the technique is applicable to many processes where plasma erosion is important. Erosion yield of materials bombarded in a high flux (up to 10 18 ion/cm 2 s) plasma environment has been previously studied using weight loss measurements. In the present study, the sputtered flux from a material is monitored by the line emission intensities of atoms eroded from the surface. The line intensities can be used to infer erosion yields after proper calibration. The method agrees well with results from weight loss measurements. Earlier work established that the material surface structure can substantially influence the erosion yield. When a change of surface morphology (e.g., cone formation) occurs, weight loss methods cannot be used to determine the erosion yield. However, the in situ erosion measurement is suitable and is used to investigate the relation between the onset of morphology changes and alternations in erosion yield during plasma bombardment. Experiments are reported for copper, as an example of a pure material, and stainless steel, as an example of an alloy system. The formation of surface cones is observed only when both the sample temperature is above a critical value and surface impurities exist. If the source of impurities is removed, or the sample temperature is lowered below the critical value, a surface rough with cones will be returned to a smooth state

  1. Morphology and Differentiation of MG63 Osteoblast Cells on Saliva Contaminated Implant Surfaces

    Directory of Open Access Journals (Sweden)

    Neda Shams

    2015-11-01

    Full Text Available Objectives: Osteoblasts are the most important cells in the osseointegration process. Despite years of study on dental Implants, limited studies have discussed the effect of saliva on the adhesion process of osteoblasts to implant surfaces. The aim of this in vitro study was to evaluate the effect of saliva on morphology and differentiation of osteoblasts attached to implant surfaces.Materials and Methods: Twelve Axiom dental implants were divided into two groups. Implants of the case group were placed in containers, containing saliva, for 40 minutes. Then, all the implants were separately stored in a medium containing MG63 human osteoblasts for a week. Cell morphology and differentiation were assessed using a scanning electron microscope and their alkaline phosphatase (ALP activity was determined. The t-test was used to compare the two groups.Results: Scanning electron microscopic observation of osteoblasts revealed round or square cells with fewer and shorter cellular processes in saliva contaminated samples, whereas elongated, fusiform and well-defined cell processes were seen in the control group. ALP level was significantly lower in case compared to control group (P<0.05.Conclusion: Saliva contamination alters osteoblast morphology and differentiation and may subsequently interfere with successful osseointegration. Thus, saliva contamination of bone and implant must be prevented or minimized.

  2. Surface modification and characterization Collaborative Research Center at ORNL

    International Nuclear Information System (INIS)

    1986-01-01

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

  3. Characterization of Pectin Nanocoatings at Polystyrene and Titanium Surfaces

    DEFF Research Database (Denmark)

    Gurzawska, Katarzyna; Dirscherl, Kai; Yihua, Yu

    2013-01-01

    The titanium implant surface plays a crucial role for implant incorporation into bone. A new strategy to improve implant integration in a bone is to develop surface nanocoatings with plant-derived polysaccharides able to increase adhesion of bone cells to the implant surface. The aim of the present...... study was to physically characterize and compare polystyrene and titanium surfaces nanocoated with different Rhamnogalacturonan-Is (RG-I) and to visualize RG-I nanocoatings. RG-Is from potato and apple were coated on aminated surfaces of polystyrene, titianium discs and titanium implants...... wettability, without any major effect on surface roughness (Sa, Sdr). Furthermore, we demonstrated that it is possible to visualize the pectin RG-Is molecules and even the nanocoatings on titanium surfaces, which have not been presented before. The comparison between polystyrene and titanium surface showed...

  4. Three-dimensional shape variation of talar surface morphology in hominoid primates.

    Science.gov (United States)

    Parr, W C H; Soligo, C; Smaers, J; Chatterjee, H J; Ruto, A; Cornish, L; Wroe, S

    2014-07-01

    The hominoid foot is of particular interest to biological anthropologists, as changes in its anatomy through time reflect the adoption of terrestrial locomotion, particularly in species of Australopithecus and Homo. Understanding the osteological morphology associated with changes in whole foot function and the development of the plantar medial longitudinal foot arch are key to understanding the transition through habitual bipedalism in australopithecines to obligate bipedalism and long-distance running in Homo. The talus is ideal for studying relationships between morphology and function in this context, as it is a major contributor to the adduction-abduction, plantar-dorsal flexion and inversion-eversion of the foot, and transmits all forces encountered from the foot to the leg. The talar surface is predominantly covered by articular facets, which have different quantifiable morphological characters, including surface area, surface curvature and orientation. The talus also presents challenges to the investigator, as its globular shape is very difficult to quantify accurately and reproducibly. Here we apply a three-dimensional approach using type 3 landmarks (slid semilandmarks) that are geometrically homologous to determine overall talar shape variations in a range of living and fossil hominoid taxa. Additionally, we use novel approaches to quantify the relative orientations and curvatures of talar articular facets by determining the principal vectors of facet orientation and fitting spheres to articular facets. The resulting metrics are analysed using phylogenetic regressions and principal components analyses. Our results suggest that articular surface curvatures reflect locomotor specialisations with, in particular, orangutans having more highly curved facets in all but the calcaneal facet. Similarly, our approach to quantifying articular facet orientation appears to be effective in discriminating between extant hominoid species, and may therefore provide a

  5. Surface Morphology and Hardness Analysis of TiCN Coated AA7075 Aluminium Alloy

    Science.gov (United States)

    Srinath, M. K.; Ganesha Prasad, M. S.

    2017-12-01

    Successful titanium carbonitride (TiCN) coating on AA7075 plates using the PVD technique depends upon many variables, including temperature, pressure, incident angle and energy of the reactive ions. Coated specimens have shown an increase in their surface hardness of 2.566 GPa. In this work, an attempt to further augment the surface hardness and understand its effects on the surface morphology was performed through heat treatments at 500°C for different duration of times. Specimen's heat treated at 500°C for 1 h exhibited a maximum surface hardness of 6.433 GPa, corresponding to an increase of 92.07%. The XRD results showed the presence of Al2Ti and AlTi3N and indicate the bond created between them. Unit cell lattice parameters in the XRD data are calculated using Bragg's law. The SEM images exhibit increasing crack sizes as the heat treatment time is increased. From the studies, the heat treatment duration can be optimized to 1 h, which exhibited an augmented surface hardness, as further increases in durations caused a drop in the surface hardness. The heat treatment effectively modified the surface hardness. Equations providing the relationships that temperature and time have with the reaction parameters are presented.

  6. Surface Sensitive Techniques for Advanced Characterization of Luminescent Materials.

    Science.gov (United States)

    Swart, Hendrik C

    2017-08-04

    The important role of surface sensitive characterization techniques such as Auger electron spectroscopy (AES), X-ray photo electron spectroscopy (XPS), time of flight scanning ion mass spectrometry (TOF-SIMS) and High resolution transmission electron microscopy (HRTEM) for the characterization of different phosphor materials is discussed in this short review by giving selective examples from previous obtained results. AES is used to monitor surface reactions during electron bombardment and also to determine the elemental composition of the surfaces of the materials, while XPS and TOF-SIMS are used for determining the surface chemical composition and valence state of the dopants. The role of XPS to determine the presence of defects in the phosphor matrix is also stated with the different examples. The role of HRTEM in combination with Energy dispersive spectroscopy (EDS) for nanoparticle characterization is also pointed out.

  7. Surface Sensitive Techniques for Advanced Characterization of Luminescent Materials

    Directory of Open Access Journals (Sweden)

    Hendrik C. Swart

    2017-08-01

    Full Text Available The important role of surface sensitive characterization techniques such as Auger electron spectroscopy (AES, X-ray photo electron spectroscopy (XPS, time of flight scanning ion mass spectrometry (TOF-SIMS and High resolution transmission electron microscopy (HRTEM for the characterization of different phosphor materials is discussed in this short review by giving selective examples from previous obtained results. AES is used to monitor surface reactions during electron bombardment and also to determine the elemental composition of the surfaces of the materials, while XPS and TOF-SIMS are used for determining the surface chemical composition and valence state of the dopants. The role of XPS to determine the presence of defects in the phosphor matrix is also stated with the different examples. The role of HRTEM in combination with Energy dispersive spectroscopy (EDS for nanoparticle characterization is also pointed out.

  8. Measurement of the surface morphology of plasma facing components on the EAST tokamak by a laser speckle interferometry approach

    Science.gov (United States)

    Hongbei, WANG; Xiaoqian, CUI; Yuanbo, LI; Mengge, ZHAO; Shuhua, LI; Guangnan, LUO; Hongbin, DING

    2018-03-01

    The laser speckle interferometry approach provides the possibility of an in situ optical non-contacted measurement for the surface morphology of plasma facing components (PFCs), and the reconstruction image of the PFC surface morphology is computed by a numerical model based on a phase unwrapping algorithm. A remote speckle interferometry measurement at a distance of three meters for real divertor tiles retired from EAST was carried out in the laboratory to simulate a real detection condition on EAST. The preliminary surface morphology of the divertor tiles was well reproduced by the reconstructed geometric image. The feasibility and reliability of this approach for the real-time measurement of PFCs have been demonstrated.

  9. Morphological Specifications of the Bird Schistosome Cercariae and Surface Carbohydrates as Receptors for Lectins

    Directory of Open Access Journals (Sweden)

    I Moebedi

    2007-04-01

    Full Text Available Background: To determine the morphological specifications of the bird schistosomes cercaria from Lymnaea gedrosiana and to detect the surface carbohydrates as receptors for host lectins in the host-parasite relationship systems such as avian schistosomiasis and human cercarial dermatitis. Methods: One hundred ninety two snails collected from Dezful areas in Khuzestan Province, in the south west of Iran, during 2005-2006 were examined for cercariae using shedding and crushing methods. In addition, surface carbohydrates on the cercariae were detected by lentil (Lens culinaris lectins. Results: From the total number of Lymnaea gedrosiana, which examined for bird schistosomes cercaria, 9(4% snails were found to be infected with furcocercus cercaria of the bird schistosomes (probably Gigantobilharzia sp.. Mannose monosaccharide CH2OH (CHOH4CHO as surface carbohydrate was also detected on the cercariae. Conclusion: Mannose carbohydrate on these cercariae may be used as receptor by lectins.

  10. The Relationship Between the Surface Morphology and Chemical Composition of Gunshot Residue Particles.

    Science.gov (United States)

    Kara, Ilker; Lisesivdin, Sefer Bora; Kasap, Mehmet; Er, Elif; Uzek, Ugur

    2015-07-01

    In this study, chemical composition and morphology of gunshot residue (GSR) of 9 × 19 mm Parabellum-type MKE (Turkey)-brand ammunition were analyzed by scanning electron microscope and energy dispersive X-ray spectrometer. GSR samples were collected by "swab" technique from the shooter's right hand immediately after shooting. According to general principles of thermodynamics, it is likely that the structures will have a more regular (homogeneous) spherical form to minimize their surface area due to very high temperatures and pressures that occur during explosion. Studied samples were collected under the same conditions with the same original ammunition, from the same firearm and a single shooter. This is because many other variables may affect size, structure, and composition in addition to the concentrations of elements of the structure. Results indicated that the chemical compositions are effective in the formation of GSR morphological structures. © 2015 American Academy of Forensic Sciences.

  11. Nano hydroxyapatite-blasted titanium surface affects pre-osteoblast morphology by modulating critical intracellular pathways.

    Science.gov (United States)

    Bezerra, Fábio; Ferreira, Marcel R; Fontes, Giselle N; da Costa Fernandes, Célio Jr; Andia, Denise C; Cruz, Nilson C; da Silva, Rodrigo A; Zambuzzi, Willian F

    2017-08-01

    Although, intracellular signaling pathways are proposed to predict the quality of cell-surface relationship, this study addressed pre-osteoblast behavior in response to nano hydroxyapatite (HA)-blasted titanium (Ti) surface by exploring critical intracellular pathways and pre-osteoblast morphological change. Physicochemical properties were evaluated by atomic force microscopy (AFM) and wettability considering water contact angle of three differently texturized Ti surfaces: Machined (Mac), Dual acid-etching (DAE), and nano hydroxyapatite-blasted (nHA). The results revealed critical differences in surface topography, impacting the water contact angle and later the osteoblast performance. In order to evaluate the effect of those topographical characteristics on biological responses, we have seeded pre-osteoblast cells on the Ti discs for up to 4 h and subjected the cultures to biological analysis. First, we have observed pre-osteoblasts morphological changes resulting from the interaction with the Ti texturized surfaces whereas the cells cultured on nHA presented a more advanced spreading process when compared with the cells cultured on the other surfaces. These results argued us for analyzing the molecular machinery and thus, we have shown that nHA promoted a lower Bax/Bcl2 ratio, suggesting an interesting anti-apoptotic effect, maybe explained by the fact that HA is a natural element present in bone composition. Thereafter, we investigated the potential effect of those surfaces on promoting pre-osteoblast adhesion and survival signaling by performing crystal violet and immunoblotting approaches, respectively. Our results showed that nHA promoted a higher pre-osteoblast adhesion supported by up-modulating FAK and Src activations, both signaling transducers involved during eukaryotic cell adhesion. Also, we have shown Ras-Erk stimulation by the all evaluated surfaces. Finally, we showed that all Ti-texturing surfaces were able to promote osteoblast differentiation

  12. Thermally sensitive block copolymer particles prepared via aerosol flow reactor method: Morphological characterization and behavior in water.

    Science.gov (United States)

    Nykänen, Antti; Rahikkala, Antti; Hirvonen, Sami-Pekka; Aseyev, Vladimir; Tenhu, Heikki; Mezzenga, Raffaele; Raula, Janne; Kauppinen, Esko; Ruokolainen, Janne

    2012-10-23

    This work describes properties of thermo-sensitive submicron sized particles having the same chemical composition but different morphologies. These particles have been prepared with an aerosol technique using dimethylformamide solutions of linear polystyrene-block-poly(N-isopropylacrylamide-block-polystyrene, PS-b-PNIPAM-b-PS. The particles were characterized by cryo-electron microscopy, microcalorimetry, and light scattering. Block-copolymers self-assembled within the particles forming onion-like, gyroid-like, and spherical morphologies having poly(N-isopropylacrylamide) matrix and physically cross-linking polystyrene domains. The particles were dispersed in aqueous media and their behavior in water was studied both below and above the lower critical solution temperature of poly(N-isopropylacrylamide). We found out that the particles with spherical and gyroid-like morphologies swell considerably in water at 20 °C, whereas at 40 °C the particles resemble more of those studied without water treatment. Light scattering experiments showed that the particles gradually aggregate and precipitate with time at 40 °C. Microcalorimetric studies revealed for all three studied morphologies that PNIPAM undergoes a two-step transition due to the different hydration levels of PNIPAM inside and outside the particles. Thicknesses of the PS and PNIPAM layers within the onion-like particles were analyzed using the TEM micrographs by fitting a model of electron density to the integrated electron intensity data. The surface layer of the particles was found out to be PNIPAM, which was supported by light scattering and microcalorimetry. It was also found out from the TEM micrograph analysis that the width of the outmost PS layer is considerably thinner than the one in the dry state prior to immersion in water, and a degradation scheme is proposed to explain these results.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  14. Morphological characterization of several strains of the rice-pathogenic bacterium Burkholderia glumae in North Sumatra

    Science.gov (United States)

    Hasibuan, M.; Safni, I.; Lisnawita; Lubis, K.

    2018-02-01

    Burkholderia glumae is a quarantine seed-borne bacterial pathogen causing panicle blight disease on rice. This pathogen has been detected in some locations in Java, and recently, farmers in North Sumatra have reported rice yield loss with symptoms similar with those on rice infeced by the rice-pathogenic bacterium B. glumae. This research was aimed to isolate several bacterial strains from several rice varieties in various locations in North Sumatra and characterize the morphology of the strains to detect and identify the unknown bacterial strains presumably B. glumae. Several rice seed varieties were collected from Medan and Deli Serdang Districts. The seed samples were extracted, isolated and purified, then grown in semi-selective media PPGA. The morphological characteristics of the bacterial strains were determined including Gram staining, bacterial colony’s and bacterial cell’s morphology. The results showed that of eleven strains isolated, two strains were Gram negative and nine strains were Gram positive. On the basis of colony morphology, all strains had circular form, flat elevation and cream colour while the colony margin varied, i.e. entire and undulate. Most strains had bacillus/rod shape (8 strains) and only 3 strains were coccus.

  15. Characterization of Saccharomyces cerevisiae natural populations for pseudohyphal growth and colony morphology.

    Science.gov (United States)

    Casalone, Enrico; Barberio, Claudia; Cappellini, Lorenzo; Polsinelli, Mario

    2005-03-01

    In this work we have analyzed the colony and cellular morphologies of natural populations of Saccharomyces cerevisiae strains in response to different environmental stimuli. Among one thousand strains grown on YPD medium, 2.5% exhibited a rough (R) colony phenotype versus a smooth (S) phenotype. When grown on the ammonium-deficient medium SLAD, 56% of the strains showed a filamentous phenotype, often associated (43.8%) with an invasive phenotype, while 4.7% of the strains exhibited only an invasive phenotype. The rough phenotype on YPD was always associated with the filamentous phenotype on SLAD. A subset of 52 strains was further characterized for the growth phenotype under different stimuli (nitrogen deprivation, addition of alcohols, growth on proline as sole nitrogen source). On 27 strains, genetic analysis of the spore products was also performed. The entire set of data showed a wide distribution of dimorphism in the yeast population and great variability with respect to the dimorphic switch capability. Some strains grew with peculiar colony morphologies under different environmental stimuli and some showed colony morphology variations. Ecological implications of the wide spreading of dimorphic behavior and the occurrence of peculiar colony morphologies in natural yeasts are discussed.

  16. Patterns of morphological variation in enamel-dentin junction and outer enamel surface of human molars.

    Science.gov (United States)

    Morita, Wataru; Yano, Wataru; Nagaoka, Tomohito; Abe, Mikiko; Ohshima, Hayato; Nakatsukasa, Masato

    2014-06-01

    Tooth crown patterning is governed by the growth and folding of the inner enamel epithelium (IEE) and the following enamel deposition forms outer enamel surface (OES). We hypothesized that overall dental crown shape and covariation structure are determined by processes that configurate shape at the enamel-dentine junction (EDJ), the developmental vestige of IEE. This this hypothesis was tested by comparing patterns of morphological variation between EDJ and OES in human permanent maxillary first molar (UM1) and deciduous second molar (um2). Using geometric morphometric methods, we described morphological variation and covariation between EDJ and OES, and evaluated the strength of two components of phenotypic variability, canalization and morphological integration, in addition to the relevant evolutionary flexibility, i.e. the ability to respond to selective pressure. The strength of covariation between EDJ and OES was greater in um2 than in UM1, and the way that multiple traits covary between EDJ and OES was different between these teeth. The variability analyses showed that EDJ had less shape variation and a higher level of morphological integration than OES, which indicated that canalization and morphological integration acted as developmental constraints. These tendencies were greater in UM1 than in um2. On the other hand, EDJ and OES had a comparable level of evolvability in these teeth. Amelogenesis could play a significant role in tooth shape and covariation structure, and its influence was not constant among teeth, which may be responsible for the differences in the rate and/or period of enamel formation. © 2014 Anatomical Society.

  17. Simultaneous Morphological and Molecular Characterization of Tatera indica in Southwestern Iran.

    Science.gov (United States)

    Mohammadi, Somayeh; Parvizi, Parviz

    2016-03-01

    Interest in Tatera indica rodent arises mostly because it is believed that this species is survived among four subspecies reported from Iran, two of which exist in Khuzestan Province. In addition, it might has a role as reservoir hosts of zoonotic cutaneous leishmaniasis in the transmission of Leishmania major in some of the widespread Asian foci including southwestern Iran. Diagnostic morphological and molecular markers for T. indica were sought by characterizing from individual specimens, such as some taxonomic features and mitochondrial cytochrome b gene that had previously proven useful for the taxonomy of rodents. Wild rodents were caught using live wooden and wire traps. The specimens were identified morphologically using external criteria and molecularly by sequencing of Cyt b gene and phylogenetic analyses. Forty one T. indica were collected and identified morphologically in Khuzestan Province, Iran. Two morphotypes of T. indica were found and classified but sequencing and phylogenetic analyses of mitochondrial Cyt b gene did not support any subspecies between two morphotypes of T. indica. Because all 21 sequences of both morphotypes of T. indica had no variation with only one common and novel haplotype (GenBank accession No KP001566). This is the first time that T. indica was characterized molecularly in Iran. There is no molecular evidence for T. indica morphotypes or subspecies, and so a population genetics approach using several polymorphic genes might be employed using species-specific molecular markers. In addition, more specimens of T. indica species in large geographical locations should be tested.

  18. Surface morphology and physical properties of partially melt textured Mn doped Bi-2223

    Directory of Open Access Journals (Sweden)

    Indu Verma

    2011-09-01

    Full Text Available The samples of Bi2Sr2Ca2Cu3-xMnxO10+δ (x = 0.0 to 0.30 were prepared by the standard solid-state reaction method. The phase identification characteristics of synthesized (HTSC materials were explored through powder X-ray diffractometer reveals that all the samples crystallize in orthorhombic structure with lattice parameters a = 5.4053 Å, b = 5.4110 Å and c = 37.0642 Å up to Mn concentration of x = 0.30. The critical temperature (Tc measured by standard four probe method has been found to depress from 108 K to 70 K as Mn content (x increases from 0.00 to 0.30. The effects of sintering temperature on the surface morphology of Bi2Sr2Ca2Cu3-xMnxO10+δ have also been investigated. The surface morphology investigated through scanning electron microscope and atomic force microscopy (SEM & AFM results that voids are decreasing but grains size increases as the Mn concentration increases besides, nanosphere like structures on the surface of the Mn doped Bi2Sr2Ca2Cu3-xMnxO10+δ (Bi-2223 samples.

  19. The Effect of Laminin-1-Doped Nanoroughened Implant Surfaces: Gene Expression and Morphological Evaluation

    Directory of Open Access Journals (Sweden)

    Humberto Osvaldo Schwartz-Filho

    2012-01-01

    Full Text Available Aim. This study aimed to observe the morphological and molecular effect of laminin-1 doping to nanostructured implant surfaces in a rabbit model. Materials and Methods. Nanostructured implants were coated with laminin-1 (test; dilution, 100 μg/mL and inserted into the rabbit tibiae. Noncoated implants were used as controls. After 2 weeks of healing, the implants were removed and subjected to morphological analysis using scanning electron microscopy (SEM and gene expression analysis using the real-time reverse transcriptase-polymerase chain reaction (RT-PCR. Results. SEM revealed bony tissue attachment for both control and test implants. Real-time RT-PCR analysis showed that the expression of osteoblast markers RUNX-2, osteocalcin, alkaline phosphatase, and collagen I was higher (1.62-fold, 1.53-fold, 1.97-fold, and 1.04-fold, resp. for the implants modified by laminin-1 relative to the control. All osteoclast markers investigated in the study presented higher expression on the test implants than controls as follows: tartrate-resistant acid phosphatase (1.67-fold, calcitonin receptor (1.35-fold, and ATPase (1.25-fold. The test implants demonstrated higher expression of inflammatory markers interleukin-10 (1.53-fold and tumour necrosis factor-α (1.61-fold relative to controls. Conclusion. The protein-doped surface showed higher gene expression of typical genes involved in the osseointegration cascade than the control surface.

  20. Surface morphology of Saccinobaculus (Oxymonadida): implications for character evolution and function in oxymonads.

    Science.gov (United States)

    Carpenter, Kevin J; Waller, Ross F; Keeling, Patrick J

    2008-04-01

    Examination of surface morphology of the oxymonad genus Saccinobaculus from the gut of the wood-feeding cockroach Cryptocercus punctulatus with scanning and transmission electron microscopy reveals several new characters not observable with light microscopy. These include small concavities covering the external surface, a glycocalyx, coated pinocytotic vesicles, and, in one species, unidentified, membrane-bounded organelles with a granular matrix that may represent peroxisomal or mitochondrial derivatives. Unlike representatives of some other oxymonad families, Saccinobaculus lacks extracellular surface structures, a holdfast, and, generally, ectobiotic bacteria. We examined the evolution of these and other characters in light of previously published phylogenies of oxymonads based on molecular data. The presence of concavities in Saccinobaculus and families Pyrsonymphidae and Oxymonadidae strengthens support for a clade comprising these three families. A glycocalyx appears to be a synapomorphy of all oxymonads, and the presence of ectobiotic bacteria also appears to be ancestral to oxymonads, but lost in Saccinobaculus. A holdfast appears to have arisen multiple times. We hypothesize that concavities may play a role in a two-step mechanism for the accumulation and internalization of specific solutes, and that the highly motile and morphologically plastic nature of Saccinobaculus cells limits the possibility of retaining a covering of ectobiotic bacteria.

  1. Evaluation of ablation efficiency and surface morphology of human teeth upon irradiation with femtosecond laser pulses

    Science.gov (United States)

    Shaheen, M. E.; Gagnon, J. E.; Fryer, B. J.

    2014-11-01

    This study investigates changes in ablation efficiency and surface morphology induced in human dental enamel and dentin upon interaction with femtosecond laser pulses at variable energies and number of laser pulses. Craters were created using a Ti:sapphire femtosecond laser ablation system operating at a wavelength of 785 nm, pulse width of 130 fs, and repetition rate of 20 Hz. Various techniques, such as optical and scanning electron microscopy and inductively coupled plasma mass spectrometry (ICP-MS), were used to evaluate ablation depth, amount of material ablated, and surface morphology of the craters. Ablation rate (ablation depth per pulse) was found to be lower in enamel than dentin with the maximum rate occurring at fluence of 12.4 J cm-2 in both materials. A drop in ablation rate was observed for fluence greater than 12.4 J cm-2 and was attributed to attenuation of laser energy due to interaction with the laser-generated particles. Above this fluence, signs of thermal effects, such as melting and formation of droplets of molten material at the sample surface, were observed. The response of the ICP-MS indicated that the amount of ablated material removed from dentin is greater than that removed from enamel by a factor of 1.5 or more at all investigated fluence.

  2. Morphological and spectroscopic characterization of laser-ablated tungsten at various laser irradiances

    Energy Technology Data Exchange (ETDEWEB)

    Akram, Mahreen; Bashir, Shazia; Hayat, Asma; Mahmood, Khaliq; Dawood, Asadullah [Government College University, Centre for Advanced Studies in Physics, Lahore (Pakistan); Rafique, Muhammad Shahid [University of Engineering and Technology, Department of Physics, Lahore (Pakistan); Bashir, M.F. [COMSATS Institute of Information Technology, Department of Physics, Lahore (Pakistan)

    2015-06-15

    The variation in surface morphology and plasma parameters of laser irradiated tungsten has been investigated as a function of irradiance. For this purpose, Nd:YAG laser (1064 nm, 10 ns, 10 Hz) is employed. Tungsten targets were exposed to various laser irradiances ranging from 6 to 50 GW/cm{sup 2} under ambient environment of argon at a pressure of 20 Torr. Scanning electron microscope analysis has been performed to analyze the surface modification of irradiated tungsten. It revealed the formation of micro- and nanoscale surface structures. In central ablated area, distinct grains and crack formation are observed, whereas peripheral ablated areas are dominated by cones and pinhole formation. It was observed that at irradiances exceeding a value of 13 GW/cm{sup 2}, the morphological trend of the observed structures has been changed from erosion to melting and re-deposition dominant phase. Ablation efficiency as a function of laser irradiance has also been investigated by measuring the crater depth using surface profilometry analysis. It is found to be maximum at an irradiance of 13 GW/cm{sup 2} and decreases at high laser irradiances. In order to correlate the accumulated effects of plasma parameters with the surface modification, laser-induced breakdown spectroscopy analysis has been performed. The electron temperature and number density of tungsten plasma have been evaluated at various laser irradiances. Initially with the increase of the laser irradiance up to 13 GW/cm{sup 2}, an increasing trend is observed for both plasma parameters due to enhanced energy deposition. Afterward, a decreasing trend is achieved which is attributed to the shielding effect. With further increase in irradiance, a saturation stage comes and insignificant changes are observed in plasma parameters. This saturation is explainable on the basis of the formation of a self-regulating regime near the target surface. Surface modifications of laser irradiated tungsten have been correlated with

  3. Surface morphology of refractive-index waveguide gratings fabricated in polymer films

    Science.gov (United States)

    Dong, Yi; Song, Yan-fang; Ma, Lei; Gao, Fang-fang

    2016-09-01

    The characteristic modifications are reported on the surface of polymeric waveguide film in the process of volume- grating fabrication. The light from a mode-locked 76 MHz femtosecond laser with pulse duration of 200 fs and wavelength of 800 nm is focused normal to the surface of the sample. The surface morphology modifications are ascribed to a fact that surface swelling occurs during the process. Periodic micro-structure is inscribed with increasing incident power. The laser-induced swelling threshold on the grating, which is higher than that of two-photon initiated photo-polymerization (TPIP) (8 mW), is verified to be about 20 mW. It is feasible to enhance the surface smoothness of integrated optics devices for further encapsulation. The variation of modulation depth is studied for different values of incident power and scan spacing. Ablation accompanied with surface swelling appears when the power is higher. By optimizing the laser carving parameters, highly efficient grating devices can be fabricated.

  4. A comprehensive physico-chemical, mineralogical and morphological characterization of Indian mineral wastes.

    Science.gov (United States)

    Gedam, Vidyadhar V; Jha, Rajesh; Labhasetwar, Pawan; Engelsen, Christian J

    2013-08-01

    This paper provides a comprehensive characterization of mineral waste such as fly ash, bottom ash, slag and construction demolition (C&D) collected from four different thermal power plants, three steel plants and three C&D waste generation sites in India. To determine utilisation potential and environmental concerns, as received fly ash, bottom ash, slag and C&D waste were analysed for physico-chemical, mineralogical and morphological properties. The physico-chemical properties analysed include pH, moisture content, acid insoluble residue, loss on ignition(LOI), carbon content, fineness, chloride content, sulphate content, reactive silica content, XRF and heavy metal analysis. Morphological and mineralogical characteristics were investigated using scanning electron microscopy-energy dispersive X-ray. Particle size distribution was obtained using particle size analyser. The material analysed has different compositions and were selected with a view to determine their suitability for different applications in cement and concrete industry and for further research studies.

  5. Surface morphology of the endolymphatic duct in the rat. A scanning electron microscopy study

    DEFF Research Database (Denmark)

    Qvortrup, K; Rostgaard, Jørgen; Bretlau, P

    1995-01-01

    were identified with the scanning electron microscope. A polygonal and oblong epithelial cell was observed in the largest number throughout the duct, and in the juxtasaccular half of the duct, two additional types of epithelial cells were observed. The scanning electron microscopic observations...... microscopy was attained by coating of the specimens with osmium tetroxide and thiocarbohydrazide followed by a continuous dehydration procedure. This technique permitted, for the first time, an investigation of the surface morphology of the epithelial cells in the endolymphatic duct. Three types of cells...... are compared and discussed with reference to previous transmission electron microscopic studies of the endolymphatic duct....

  6. Surface morphology study of Zr-based amorphous alloys after immersion in boiling nitric acid medium

    Science.gov (United States)

    Sharma, Poonam; Dhawan, Anil; Sharma, S. K.

    2016-05-01

    Weight loss studies have been performed to determine the corrosion resistance of amorphous Zr60Nb2Al10Ni8Cu20 and Zr59Nb3Al10Ni8Cu20 alloys in aqueous HNO3 media at boiling temperature. The FESEM micrographs has been obtained to know the surface morphology of specimens after immersion in 11.5M boiling aqueous HNO3 media. Zr59Nb3Al10Ni8Cu20 alloy shows better corrosion resistance in nitric acid media than Zr60Nb2Al10Ni8Cu20 alloy.

  7. Prediction Surface Morphology of Nanostructure Fabricated by Nano-Oxidation Technology

    OpenAIRE

    Huang, Jen-Ching; Chang, Ho; Kuo, Chin-Guo; Li, Jeen-Fong; You, Yong-Chin

    2015-01-01

    Atomic force microscopy (AFM) was used for visualization of a nano-oxidation technique performed on diamond-like carbon (DLC) thin film. Experiments of the nano-oxidation technique of the DLC thin film include those on nano-oxidation points and nano-oxidation lines. The feature sizes of the DLC thin film, including surface morphology, depth, and width, were explored after application of a nano-oxidation technique to the DLC thin film under different process parameters. A databank for process ...

  8. Application of image flow cytometry for the characterization of red blood cell morphology

    Science.gov (United States)

    Pinto, Ruben N.; Sebastian, Joseph A.; Parsons, Michael; Chang, Tim C.; Acker, Jason P.; Kolios, Michael C.

    2017-02-01

    Red blood cells (RBCs) stored in hypothermic environments for the purpose of transfusion have been documented to undergo structural and functional changes over time. One sign of the so-called RBC storage lesion is irreversible damage to the cell membrane. Consequently, RBCs undergo a morphological transformation from regular, deformable biconcave discocytes to rigid spheroechinocytes. The spherically shaped RBCs lack the deformability to efficiently enter microvasculature, thereby reducing the capacity of RBCs to oxygenate tissue. Blood banks currently rely on microscope techniques that include fixing, staining and cell counting in order to morphologically characterize RBC samples; these methods are labor intensive and highly subjective. This study presents a novel, high-throughput RBC morphology characterization technique using image flow cytometry (IFC). An image segmentation template was developed to process 100,000 images acquired from the IFC system and output the relative spheroechinocyte percentage. The technique was applied on samples extracted from two blood bags to monitor the morphological changes of the RBCs during in vitro hypothermic storage. The study found that, for a given sample of RBCs, the IFC method was twice as fast in data acquisition, and analyzed 250-350 times more RBCs than the conventional method. Over the lifespan of the blood bags, the mean spheroechinocyte population increased by 37%. Future work will focus on expanding the template to segregate RBC images into more subpopulations for the validation of the IFC method against conventional techniques; the expanded template will aid in establishing quantitative links between spheroechinocyte increase and other RBC storage lesion characteristics.

  9. Characterization of white grub (Melolonthidae; Coleoptera in salak plantation based on morphology and protein banding pattern

    Directory of Open Access Journals (Sweden)

    SUGIYARTO

    2009-07-01

    Full Text Available Maryati KT, Sugiyarto. 2010. Characterization of white grub (Melolonthidae; Coleoptera in salak plantation based on morphology and protein banding pattern. Nusantara Bioscience 1: 72-77. This research aims to find out the white grub (Melolonthidae; Coleoptera variability based on the morphological characteristic and protein banding pattern found in ”salak pondoh” farm in Regencies of Sleman, Yogyakarta and Magelang, Central Java. Each area has five sampling points. Morphological analysis on white grub was conducted using descriptive method and analysis on protein banding pattern was conducted using qualitative analysis based on the presence or absent of band pattern on the gel, and qualitatively based on the relative mobility value (Rf of protein. The result indicated that the white grub in Sleman and Magelang, based on morphology characteristic is only one species, namely Holothricia sp. Based on the protein banding pattern, the white grub sample have differences of protein band number and protein molecular weight. Key words: Salacca zalacca, white grub, morphology, protein banding pattern.Abstrak. Maryati KT, Sugiyarto. 2010. Karakterisasi lundi putih (Melolonthidae: Coleoptera pada pertanaman salak berdasarkan ciri morfologi dan pola pita protein. Nusantara Bioscience 1: 72-77. Penelitian ini bertujuan untuk mengetahui keanekaragaman lundi putih (Melolonthidae; Coleoptera berdasarkan ciri morfologi dan pola pita protein yang ditemukan di lahan pertanaman salak pondoh di Kabupaten Sleman, Yogyakarta dan Kabupaten Magelang, Jawa Tengah. Pada masing-masing wilayah diambil lima titik sampling. Analisis morfologi lundi putih digunakan metode deskriptif, dan analisis pola pita protein digunakan analisis kualitatif berdasarkan muncul tidaknya pola pita pada gel, dan secara kuantitatif berdasarkan nilai mobilitas relatif protein (RF. Hasil penelitian menunjukkan bahwa sampel lundi putih di Kabupaten Sleman dan Magelang, berdasar karakter

  10. Lectures on Modification, Characterization and Modeling of Surfaces. Vol. I

    International Nuclear Information System (INIS)

    1997-01-01

    The field of surfaces and thin films is now so broad that has applications in protective coatings, electronic devices, displays, sensors, optical equipment, bio-compatible coatings for surgical implants, odontological and cardiovascular use, and numerous other technologies that depend on the deposition processes. Even though there exist well established methods for both, production and characterization of high-quality surfaces, the interest in finding alternative methods more reliable and less expensive is one of the challenges of present technologies. In this special issue the attention is focused on some areas concerning surface modification, characterization and modeling of surfaces. The volume contains reviews and articles on plasma processing, nitriding, nitrocarburising, diamond-like films, laser and ion-beam surface modification,texture in films and coatings, nuclear techniques in surface analysis, electron spectroscopies, ion scattering spectroscopy, secondary ion mass spectroscopy, STM and AFM applications to surface science, nano structure preparation magnetic and electric properties, surface modeling, calculation of electric and magnetic properties, statistical thermodynamics of surfaces

  11. Surface chemistry and morphology of the solid electrolyte interphase on silicon nanowire lithium-ion battery anodes

    KAUST Repository

    Chan, Candace K.

    2009-04-01

    Silicon nanowires (SiNWs) have the potential to perform as anodes for lithium-ion batteries with a much higher energy density than graphite. However, there has been little work in understanding the surface chemistry of the solid electrolyte interphase (SEI) formed on silicon due to the reduction of the electrolyte. Given that a good, passivating SEI layer plays such a crucial role in graphite anodes, we have characterized the surface composition and morphology of the SEI formed on the SiNWs using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). We have found that the SEI is composed of reduction products similar to that found on graphite electrodes, with Li2CO3 as an important component. Combined with electrochemical impedance spectroscopy, the results were used to determine the optimal cycling parameters for good cycling. The role of the native SiO2 as well as the effect of the surface area of the SiNWs on reactivity with the electrolyte were also addressed. © 2009 Elsevier B.V. All rights reserved.

  12. Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization.

    Science.gov (United States)

    Liu, Feng; Ferdous, Sunzida; Wan, Xianjian; Zhu, Chenhui; Schaible, Eric; Hexemer, Alexander; Wang, Cheng; Russell, Thomas P

    2017-01-29

    Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices have used devices prepared by spin coating, a process that is not amenable to large-scale fabrication. This mismatch in device fabrication makes it difficult to translate quantitative results obtained in the laboratory to the commercial level, making optimization difficult. Using a mini-slot die coater, this mismatch can be resolved by translating the commercial process to the laboratory and characterizing the structure formation in the active layer of the device in real time and in situ as films are coated onto a substrate. The evolution of the morphology was characterized under different conditions, allowing us to propose a mechanism by which the structures form and grow. This mini-slot die coater offers a simple, convenient, material efficient route by which the morphology in the active layer can be optimized under industrially relevant conditions. The goal of this protocol is to show experimental details of how a solar cell device is fabricated using a mini-slot die coater and technical details of running in situ structure characterization using the mini-slot die coater.

  13. Morphological characterization of lentil (lens culinaris medik.) landraces from castilla y leon, spain

    International Nuclear Information System (INIS)

    Aslam, K.; Arif, M.

    2014-01-01

    The characterization of plant genetic resources has a significant impact on their possible future use in lentil breeding programs and also, in the activity of germplasm collections. In this work we have characterized 27 lentil landraces from the region of Castilla and Leon (plateau in Northern Spain), existing among them two different morphological groups according to the characteristics of the seeds (Macrosperma and Microsperma). Fifteen morpho-agronomical characters were measured for data collection. A principal components analysis allowed the definition of the 5 factors which explain 83.7% of the cumulative variance. The first factor explains 25.3% of total variation and it is related to seed production. We performed a cluster analysis obtaining 5 groups, each one defined by the average values of the employed characters. 37.0% of landraces were included in group 5, characterized by a high mean of the harvest index (38.4) and also a high mean value (74.4) for the number of pods. To study the seeds we used a correspondence analysis 6 dimensions which explained the 80.9% of the variance were chosen. Two cluster analysis were carried out using the coordinates of the aforementioned analysis. The aim of this work was to study the morphological variability of these populations and to discover the relationship among them. (author)

  14. Caracterização morfológica e classificação da superfície foliar de pimentas quanto à presença de tricomas e domácias Morphological characterization and surface classification of chili pepper leaves considering trichomes and domatia

    Directory of Open Access Journals (Sweden)

    Cláudia Helena C Matos

    2011-06-01

    interactions among plants, herbivores and natural enemies. Variations on such characteristics are determinant on the occurrence, abundance and diversity of organisms that exploit that habitat. The leaf surface of four Capsicum pepper species was characterized, focusing on the presence of trichomes and domatia. The objective is to identify possible mite resistance mechanisms on these plants. The classification key of pepper leaves was based on presence/absence, density and distribution of trichomes. The counting of trichomes was done in an area of 5 cm², from the medium third of each leaf. We assessed the trichomes from the limb, ribs and domatia. The pepper species significantly differed on the density of domatia and trichomes present on the ribs and limbs of their leaves. A significant difference was observed on the total density of trichomes/cm² and on the number of trichomes/domatia. From the five Capsicum species evaluated, only C. baccatum var. pendulum (hot pepper, variety girl finger pepper does not have domatia neither trichomes in any part of its leaves. The highest domatia density was found on C. baccatum var. praetermissum, which has the highest trichome density in all leaf parts and the only one with significant density of limb trichomes. The variation of the presence, distribution and density of trichomes and domatia may be determinant on the occurrence of herbivorous and predatory mites on plants. Such structures can act as a resistance mechanism against herbivore mites or may favor the presence of predatory and fungivorous mites due to provision of shelter sites. We propose here a surface classification scale of chili pepper leaves varying from 1 to 5 taking into account the number and density of observed trichomes and domatia.

  15. Control and characterization of textured, hydrophobic ionomer surfaces

    Science.gov (United States)

    Wang, Xueyuan

    Polymer thin films are of increasing interest in many industrial and technological applications. Superhydrophobic, self-cleaning surfaces have attracted a lot of attention for their application in self-cleaning, anti-sticking coatings, stain resistance, or anti-contamination surfaces in diverse technologies, including medical, transportation, textiles, electronics and paints. This thesis focuses on the preparation of nanometer to micrometer-size particle textured surfaces which are desirable for super water repellency. Textured surfaces consisting of nanometer to micrometer-sized lightly sulfonated polystyrene ionomer (SPS) particles were prepared by rapid evaporation of the solvent from a dilute polymer solution cast onto silica. The effect of the solvent used to spin coat the film, the molecular weight of the ionomer, and the rate of solvent evaporation were investigated. The nano-particle or micron-particle textured ionomer surfaces were prepared by either spin coating or solution casting ionomer solutions at controlled evaporation rates. The surface morphologies were consistent with a spinodal decomposition mechanism where the surface first existed as a percolated-like structure and then ripened into droplets if molecular mobility was retained for sufficient time. The SPS particles or particle aggregates were robust and resisted deformation even after annealing at 120°C for one week. The water contact angles on as-prepared surfaces were relatively low, ~ 90° since the polar groups in ionomer reduce the surface hydrophobicity. After chemical vapor deposition of 1H,1H,2H,2H-perfluorooctyltrichlorosilane, the surface contact angles increased to ~ 109° on smooth surfaces and ~140° on the textured surfaces. Water droplets stuck to these surfaces even when tilted 90 degrees. Superhydrophobic surfaces were prepared by spraying coating ionomer solutions and Chemical Vapor Deposition (CVD) of 1H,1H,2H,2H-perfluorooctyltrichlorosilane onto textured surfaces. The

  16. Abnormal surface morphology of the central sulcus in children with attention-deficit/hyperactivity disorder

    Directory of Open Access Journals (Sweden)

    Shuyu eLi

    2015-08-01

    Full Text Available The central sulcus (CS divides the primary motor and somatosensory areas, and its three-dimensional (3D anatomy reveals the structural changes of the sensorimotor regions. Attention-deficit/hyperactivity disorder (ADHD is a neurodevelopmental disorder that is associated with sensorimotor and executive function deficits. However, it is largely unknown whether the morphology of the CS alters due to inappropriate development in the ADHD brain. Here, we employed the sulcus-based morphometry approach to investigate the 3D morphology of the CS in 42 children whose ages spanned from 8.8 to 13.5 years (21 with ADHD and 21 controls. After automatic labeling of each CS, we computed 7 regional shape metrics for each CS, including the global average length, average depth, maximum depth, average span, surface area, average cortical thickness and local sulcal profile. We found that the average depth and maximum depth of the left CS as well as the average cortical thickness of bilateral CS in the ADHD group were significantly larger than those in the healthy children. Moreover, significant between-group differences in the sulcal profile had been found in middle sections of the CSs bilaterally, and these changes were positively correlated with the hyperactivity-impulsivity scores in the children with ADHD. Altogether, our results provide evidence for the abnormity of the CS anatomical morphology in children with ADHD due to the structural changes in the motor cortex, which significantly contribute to the clinical symptomatology of the disorder.

  17. The ultrastructural surface morphology of oral cancer cells and keratinocytes after exposure to chitosan

    Science.gov (United States)

    Fatimah; Sarsito, A. S.; Wimardhani, Y. S.

    2017-08-01

    Low-molecular-weight chitosan (LMWC) has the same selective cytotoxic effects on oral cancer cells as cisplatin. The cell deaths caused by the anticancer characteristics of chitosan show that apoptosis is not the death pathway of the primary cells involved. The interactions between LMWC and the cells need to be explored. The objective of this study was to compare the ultrastructural morphology of oral Squamous Cell Carcinoma (SCC Ca)-922 and noncancer keratinocyte HaCaT cell lines after exposure to LMWC and cisplatin. The cells were treated with LMWC and cisplatin, and their ultrastructural morphology was analyzed using scanning electron micrographs. Features of early apoptosis, seen as the loss of microvilli, were detected in the LMWC-exposed Ca9-22 cells, and there was a material surrounding the cells. In contrast, the LMWC-exposed HaCaT cells showed no changes related to apoptosis. The results were the opposite when cisplatin was used. This study confirms that there are differences in the ultrastructural surface morphology of LMWC-exposed and cisplatin-exposed oral cancer cells and keratinocytes that could be correlated with their biological activity.

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  19. Helium concentration in tungsten nano-tendril surface morphology using Elastic Recoil Detection

    International Nuclear Information System (INIS)

    Woller, K.B.; Whyte, D.G.; Wright, G.M.; Doerner, R.P.; De Temmerman, G.

    2013-01-01

    Helium (He) concentrations in tungsten nano-tendrils (W fuzz) have been measured for the first time using Elastic Recoil Detection (ERD). Fuzzy and non-fuzzy W surfaces were analyzed in order to illuminate the role of He in the transition in surface morphologies. Samples grown in the PISCES-A and PILOT-PSI experiments allowed a survey of surface temperature ranging from T s = 470–2595 K and of He fluence on the order of Φ He ∼ 10 24 –10 27 ions/m 2 . He concentrations measured in the bulk of W fuzz layers are roughly uniform with bulk He concentration 1–4 at.% while samples with just He in the near surface peaked at 1–2 at.%. This confirms that the nano-tendrils are filled with high pressure He bubbles since the solubility of He in W is ∼10 −5 at.%. This indicates that the ∼1000 K temperature fuzz-growth threshold is determined by the response of the W, not the near-surface He concentration

  20. Effect of surface morphology and densification on the infrared emissivity of C/SiC composites

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Fuyuan, E-mail: wangfy1986@gmail.com; Cheng, Laifei; Zhang, Qing, E-mail: zhangqing@nwpu.edu.cn; Zhang, Litong

    2014-09-15

    Highlights: • The cauliflower-like microstructure improved the infrared emissivity multiply. • The infrared emissivity decreased continually with the improving surface flatness. • The densification process boosted the infrared emissivity. - Abstract: The effects of surface morphology and densification on the infrared emissivity of 2D C/SiC composites were investigated in 6–16 μm from 1000 °C to 1600 °C. As the sample surface was polished, the reflection and scattering for the electromagnetic waves of thermal radiation were reduced, causing a sustained decrease in the infrared emissivity. The space-variant polarizations caused by the cauliflower-like microstructure were enervated in the smooth surface, which enhanced the reduction trendy in the infrared emissivity. In densification process, the increasing SiC content and the growing amount of the cauliflower-like microstructure on sample surface improved the infrared emissivity of C/SiC composites, while the decreasing porosity decreased it. Due to the greater positive effects on the thermal radiation during the densification process, the infrared emissivity of C/SiC composites increased successively with density.

  1. Low energy oxygen ion beam modification of the surface morphology and chemical structure of polyurethane fibers

    International Nuclear Information System (INIS)

    Wong, K.H.; Zinke-Allmang, M.; Wan, W.K.; Zhang, J.Z.; Hu, P.

    2006-01-01

    Energetic O + ions were implanted into polyurethane (PU) fiber filaments, at 60 and 100 keV with doses of 5 x 10 14 and 1 x 10 15 ions/cm 2 , to modify the near-surface fiber morphology. The implantations were performed at room temperature and at -197 deg. C, a temperature well below the glass transition temperature for this system. At room temperature, the lower energy implantation heats the fibers primarily near their surface, causing the fiber surface to smoothen and to develop a flattened shape. At the higher energy, the ion beam deposits its energy closer to the fiber core, heating the fiber more uniformly and causing them to re-solidify slowly. This favors a cylindrical equilibrium shape with a smooth fiber surface and no crack lines. The average fiber diameter reduced during 100 keV implantation from 3.1 to 2.3 μm. At -197 deg. C, the ion implantation does not provide enough heat to cause notable physical modifications, but the fibers crack and break during subsequent warming to room temperature. The dose dependence of the crack formation along the fiber intersections is presented. The ion beams further cause near-surface chemical modifications in the fibers, particularly introducing two new chemical functional groups (C-(C=O)-C and C-N-C)

  2. Nano-microsized modification of the surface morphology and composition of Ti-based dental implants

    Science.gov (United States)

    Joob, Arpad F.; Divinyi, T.; Fazekas, A.; Daroczi, C. S.; Karacs, A.; Peto, G.

    2001-11-01

    It can be concluded that surface treatment with high power Nd laser pulses induces unique morphology with sizes in ten micron and 50 nanometer ranges and being topologically isomorf with the plane. It is clear that the 1-10 micrometer elements do not change strongly the osseintegration compared to the flat surface. On the other hand this surface in 20-50 micrometer range already enhance the osseointegration indicating a strong size dependens. The effect of the nanosized elements can be suggested also because their density has been increased with laser intensity. These two effects can not be separated with available data. It is evident that several questions in connection with laser treatment of surfaces such as first of all the time course of bone formation await further studies. Namely, if microgeometry plays a role in bone formation then the process of osseointegration should be also studied in conjunction with the comparisons of the various surfaces. It is hoped that our future studies can give responses to more questions and the results will contribute to the implementation of novel clinically successful techniques to improve the reliability of dental implants.

  3. Effect of surface diffusion on morphology and scaling properties during glancing angle deposition

    Science.gov (United States)

    Mukherjee, Srijit

    The objective of this research work is to study the effect of surface diffusion on the morphology of porous thin films grown by Glancing Angle Deposition (GLAD) wherein atomic shadowing is the dominant physical phenomenon responsible for growth of isolated nano-rod structures. The morphology has been analyzed in terms of change in the width of the nanorods w at a given height h as well as changes in scaling relations as a function of diffusion length scale. Atomic shadowing during kinetically limited physical vapor deposition causes a chaotic instability in the layer morphology that leads to nanorod growth. GLAD experiments indicate that the rod morphology, in turn, exhibits a chaotic instability with increasing surface diffusion. The measured rod width versus growth temperature converges onto a single curve for metallic systems when normalized by the melting point Tm. A model based on mean field nucleation theory reveals a transition from a two- to three-dimensional growth regime at (0.20 +/- 0.03) x Tm and an activation energy for diffusion on curved surfaces of (2.46 +/- 0.02) x kTm. The consistency in the GLAD data suggests that the effective mass transport on a curved surface is described by a single normalized activation energy that is applicable to all elemental metals. Metallic nanorods grown by GLAD at Ts = 300--1123 K exhibit self-affine scaling, where the average rod width w increases with height h according to w ∝ h p. The growth exponent p for the investigated metals (Ta, Nb, Cr and Al) varies with temperature and material but collapses onto a single curve when plotted against the homologous temperature theta = Ts/Tm. It decreases from p = 0.5 at theta = 0 to 0.39 at theta = 0.22, consistent with reported theoretical predictions, but exhibits a transition to an anomalous value of p = 0.7 at theta = 0.26, followed by a decrease to 0.33 at theta = 0.41. The change in the scaling relations has been related to changes in the surface roughness of the

  4. Evolution effects of the copper surface morphology on the nucleation density and growth of graphene domains at different growth pressures

    Energy Technology Data Exchange (ETDEWEB)

    Hedayat, Seyed Mahdi [Transport Phenomena & Nanotechnology Lab., School of Chemical Engineering, College of Engineering, University of Tehran (Iran, Islamic Republic of); Karimi-Sabet, Javad, E-mail: j_karimi@alum.sharif.edu [NFCRS, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Shariaty-Niassar, Mojtaba, E-mail: mshariat@ut.ac.ir [Transport Phenomena & Nanotechnology Lab., School of Chemical Engineering, College of Engineering, University of Tehran (Iran, Islamic Republic of)

    2017-03-31

    Highlights: • Manipulation of the Cu surface morphology in a wide range by electropolishing treatment. • Comparison of the nucleation density of graphene at low pressure and atmospheric pressure CVD processes. • Controlling the evolution of the Cu surface morphology inside a novel confined space. • Growth of large-size graphene domains. - Abstract: In this work, we study the influence of the surface morphology of the catalytic copper substrate on the nucleation density and the growth rate of graphene domains at low and atmospheric pressure chemical vapor deposition (LPCVD and APCVD) processes. In order to obtain a wide range of initial surface morphology, precisely controlled electropolishing methods were developed to manipulate the roughntreess value of the as-received Cu substrate (RMS = 30 nm) to ultra-rough (RMS = 130 nm) and ultra-smooth (RMS = 2 nm) surfaces. The nucleation and growth of graphene domains show obviously different trends at LPCVD and APCVD conditions. In contrast to APCVD condition, the nucleation density of graphene domains is almost equal in substrates with different initial roughness values at LPCVD condition. We show that this is due to the evolution of the surface morphology of the Cu substrate during the graphene growth steps. By stopping the surface sublimation of copper substrate in a confined space saturated with Cu atoms, the evolution of the Cu surface was impeded. This results in the reduction of the nucleation density of graphene domains up to 24 times in the pre-smoothed Cu substrates at LPCVD condition.

  5. Identification and characterization of the surface proteins of Clostridium difficile

    Energy Technology Data Exchange (ETDEWEB)

    Dailey, D.C.

    1988-01-01

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

  6. Structure, composition and morphology of bioactive titanate layer on porous titanium surfaces

    Science.gov (United States)

    Li, Jinshan; Wang, Xiaohua; Hu, Rui; Kou, Hongchao

    2014-07-01

    A bioactive coating was produced on pore surfaces of porous titanium samples by an amendatory alkali-heat treatment method. Porous titanium was prepared by powder metallurgy and its porosity and average size were 45% and 135 μm, respectively. Coating morphology, coating structure and phase constituents were examined by SEM, XPS and XRD. It was found that a micro-network structure with sizes of bone-like carbonate-hydroxylapatite showing a good biocompatibility was detected on the coating surface. And the redundant Ca advanced the bioactivity of the coating. Thus, the present modification is expected to allow the use of the bioactive porous titanium as artificial bones even under load-bearing conditions.

  7. Surface morphology study on CdZnTe crystals by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay, M.; George, M.A.; Burger, A.; Collins, W.E.; Silberman, E. [Fisk Univ., Nashville, TN (United States)

    1993-03-01

    The study of the crystal surface morphology of CdZnTe is important for the understanding of the fundamentals of crystal growth in order to improve the crystal quality which is essential in applications such as substrates for epitaxy or performance of devices, i.e., room temperature nuclear spectrometers. We present a first atomic force microscopy study on CdZnTe. Cleaved (110) surfaces were imaged in the ambient and an atomic layer step structure was revealed. The effects of thermal annealing on the atomic steps together with Te precipitation along these steps are discussed in terms of deformation due to stress relief and the diffusion of tellurium precipitates. 12 refs., 3 figs.

  8. Morphology modification of gold nanoparticles from nanoshell to C-shape: Improved surface enhanced Raman scattering

    International Nuclear Information System (INIS)

    Xing, Ting-Yang; Zhu, Jian; Li, Jian-Jun; Zhao, Jun-Wu

    2016-01-01

    Morphology modification of nanostructures is of great interest, because it can be used to fabricate nanostructures which are hard to be done using other methods. Different from traditional lithographic technique which is slow and expensive, morphology modification is easy, cheap, and reproducible. In this paper, modification of the optical and morphological properties of a hollow gold nanoshell (HGNS) is achieved by using H 2 O 2 as an oxidizer. The reshaping of these nanostructures has been demonstrated as a consequence of an oxidation process in which HGNSs are dissolved by H 2 O 2 under the acidic conditions provided by HCl. We investigate the oxidation process by a transmission electron microscope and propose a reshaping model involving four different shapes (HGNS, HGNS with hole, gold nanoring, and C-shaped gold nanoparticle) which are corresponding to the oxidation products of HGNSs at different pH values. Besides, the surface enhanced Raman scattering (SERS) activity of each oxidation product has been evaluated by using rhodamine 6G as the Raman active probe. It has been observed that the C-shaped gold nanoparticles which are corresponding to the oxidation products at the minimum pH value have the highest SERS activity and this result can also be interpreted by discrete-dipole approximation simulations. We demonstrate that the morphology modification of HGNSs becomes possible in a controlled manner using wet chemistry and can be used in preparation of gold nanoparticles such as HGNS with hole, gold nanoring, and C-shaped gold nanoparticle with large SERS activity. These nanostructures must have potential use in many plasmonic areas, including sensing, catalysis, and biomedicine.

  9. Preparation of surface enhanced Raman substrate and its characterization

    Science.gov (United States)

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

    2017-10-01

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

  10. Controlled surface morphology and hydrophilicity of polycaprolactone toward human retinal pigment epithelium cells

    International Nuclear Information System (INIS)

    Shahmoradi, Saleheh; Yazdian, Fatemeh; Tabandeh, Fatemeh; Soheili, Zahra-Soheila; Hatamian Zarami, Ashraf Sadat; Navaei-Nigjeh, Mona

    2017-01-01

    Applying scaffolds as a bed to enhance cell proliferation and even differentiation is one of the treatment of retina diseases such as age-related macular degeneration (AMD) which deteriorating photoreceptors and finally happening blindness. In this study, aligned polycaprolactone (PCL) nanofibers were electrospun and at different conditions and their characteristics were measured by scanning electron microscope (SEM) and contact angle. Response surface methodology (RSM) was used to optimize the diameter of fabricated nanofibers. Two factors as solution concentration and voltage value were considered as independent variables and their effects on nanofibers' diameters were evaluated by central composite design and the optimum conditions were obtained as 0.12 g/mL and 20 kV, respectively. In order to decrease the hydrophobicity of PCL, the surface of the fabricated scaffolds was modified by alkaline hydrolysis method. Contact time of the scaffolds and alkaline solution and concentration of alkaline solution were optimized using Box Behnken design and (120 min and 5 M were the optimal, respectively). Contact angle measurement showed the high hydrophilicity of treated scaffolds (with contact angle 7.48°). Plasma surface treatment was applied to compare the effect of using two kinds of surface modification methods simultaneously on hydrolyzed scaffolds. The RPE cells grown on scaffolds were examined by immunocytochemistry (ICC), MTT and continuous inspection of cellular morphology. Interestingly, Human RPE cells revealed their characteristic morphology on hydrolyzed scaffold well. As a result, we introduced a culture substrate with low diameter (185.8 nm), high porosity (82%) and suitable hydrophilicity (with contact angle 7.48 degree) which can be promising for hRPE cell transplantation. - Highlights: • Dimethylformamide (DMF) has significant effect on reduction of fibers' diameter. • Having high hydrophilicity by alkaline hydrolysis • Suitable

  11. Studies on the Optical Properties and Surface Morphology of Cobalt Phthalocyanine Thin Films

    Directory of Open Access Journals (Sweden)

    Benny Joseph

    2008-01-01

    Full Text Available Thin films of Cobalt Phthalocyanine (CoPc are fabricated at a base pressure of 10-5 m.bar using Hind-Hivac thermal evaporation plant. The films are deposited on to glass substrates at various temperatures 318, 363, 408 and 458K. The optical absorption spectra of these thin films are measured. The present studies reveal that the optical band gap energies of CoPc thin films are almost same on substrate temperature variation. The structure and surface morphology of the films deposited on glass substrates of temperatures 303, 363 and 458K are studied using X-ray diffractograms and Scanning Electron Micrographs (SEM, which show that there is a change in the crystallinity and surface morphology due to change in the substrate temperatures. Full width at half maximum (FWHM intensity of the diffraction peaks is also found reduced with increasing substrate temperatures. Scanning electron micrographs show that these crystals are needle like, which are interconnected at high substrate temperatures. The optical band gap energy is almost same on substrate temperature variation. Trap energy levels are also observed for these films.

  12. On the Morphology of the SDS Film on the Surface of Borosilicate Glass

    Directory of Open Access Journals (Sweden)

    Zih-Yao Shen

    2017-05-01

    Full Text Available Surfactant films on solid surfaces have attracted much attention because of their scientific interest and applications, such as surface treatment agent, or for micro- or nano-scale templates for microfluidic devices. In this study, anionic surfactant sodium dodecyl sulfate (SDS solutions with various charged inorganic salts was spread on a glass substrate and dried to form an SDS thin film. Atomic force microscopy (AFM was employed to observe the micro-structure of the SDS thin film. The effects of inorganic salts on the morphology of the SDS film were observed and discussed. The results of experiments demonstrated that pure SDS film formed patterns of long, parallel, highly-ordered stripes. The existence of the inorganic salt disturbed the structure of the SDS film due to the interaction between the cationic ion and the anionic head groups of SDS. The divalent ion has greater electrostatic interaction with anionic head groups than that of the monovalent ion, and causes a gross change in the morphology of the SDS film. The height of the SDS bilayer measured was consistent with the theoretical value, and the addition of the large-sized monovalent ion would lead to lowering the height of the adsorbed structures.

  13. New horizons in selective laser sintering surface roughness characterization

    Science.gov (United States)

    Vetterli, M.; Schmid, M.; Knapp, W.; Wegener, K.

    2017-12-01

    Powder-based additive manufacturing of polymers and metals has evolved from a prototyping technology to an industrial process for the fabrication of small to medium series of complex geometry parts. Unfortunately due to the processing of powder as a basis material and the successive addition of layers to produce components, a significant surface roughness inherent to the process has been observed since the first use of such technologies. A novel characterization method based on an elastomeric pad coated with a reflective layer, the Gelsight, was found to be reliable and fast to characterize surfaces processed by selective laser sintering (SLS) of polymers. With help of this method, a qualitative and quantitative investigation of SLS surfaces is feasible. Repeatability and reproducibility investigations are performed for both 2D and 3D areal roughness parameters. Based on the good results, the Gelsight is used for the optimization of vertical SLS surfaces. A model built on laser scanning parameters is proposed and after confirmation could achieve a roughness reduction of 10% based on the S q parameter. The Gelsight could be successfully identified as a fast, reliable and versatile surface topography characterization method as it applies to all kind of surfaces.

  14. Mechanical and morphological characterization of a bio-nanocomposite hydroxyapatite / polyurethane

    International Nuclear Information System (INIS)

    Andrade, Sabina da Memoria Cardoso de; Dias, Carmen Gilda Barroso Tavares; Zavaglia, Cecilia Amelia de Carvalho

    2011-01-01

    Nanocomposites based on biocompatible polymers and hydroxyapatite are wide acceptance as bone grafts, the composition, structure and similarity to natural bone and also due to the properties functional, such as surface and mechanical strength. This work there was the making of a bionanocomposite, using nanostructured hydroxyapatite interconnected by polyurethane, generated from the actions of poly(vinylalcohol) and toluene isocyanate HDT. The formation kinetics was monitored by the bionanocomposite spectroscopy and Fourier transform infrared FTIR. The material showed good properties both mechanical and morphology. (author)

  15. Surface morphological modification of crosslinked hydrophilic co-polymers by nanosecond pulsed laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Primo, Gastón A.; Alvarez Igarzabal, Cecilia I. [IMBIV (CONICET), Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Edificio de Ciencias II, Ciudad Universitaria, Córdoba X5000HUA (Argentina); Pino, Gustavo A.; Ferrero, Juan C. [INFIQC (CONICET), Departamento de Fisicoquímica, Facultad de Ciencias Químicas, and Centro Láser de Ciencias Moleculares, Universidad Nacional de Córdoba, Córdoba X5000IUS (Argentina); Rossa, Maximiliano, E-mail: mrossa@fcq.unc.edu.ar [INFIQC (CONICET), Departamento de Fisicoquímica, Facultad de Ciencias Químicas, and Centro Láser de Ciencias Moleculares, Universidad Nacional de Córdoba, Córdoba X5000IUS (Argentina)

    2016-04-30

    Graphical abstract: - Highlights: • Laser-induced surface modification of crosslinked hydrophilic co-polymers by ns pulses. • Formation of ablation craters observed under most of the single-pulse experimental conditions. • UV laser foaming of dried hydrogel samples resulting from single- and multiple-pulse experiments. • Threshold values of the incident laser fluence reported for the observed surface modifications. • Lower threshold fluences for acrylate-based, compared to acrylamide-based hydrogels. - Abstract: This work reports an investigation of the surface modifications induced by irradiation with nanosecond laser pulses of ultraviolet and visible wavelengths on crosslinked hydrophilic co-polymeric materials, which have been functionalized with 1-vinylimidazole as a co-monomer. A comparison is made between hydrogels differing in the base co-monomer (N,N-dimethylaminoethyl methacrylate and N-[3-(dimethylamino)propyl] methacrylamide) and in hydration state (both swollen and dried states). Formation of craters is the dominant morphological change observed by ablation in the visible at 532 nm, whereas additional, less aggressive surface modifications, chiefly microfoams and roughness, are developed in the ultraviolet at 266 nm. At both irradiation wavelengths, threshold values of the incident laser fluence for the observation of the various surface modifications are determined under single-pulse laser irradiation conditions. It is shown that multiple-pulse irradiation at 266 nm with a limited number of laser shots can be used alternatively for generating a regular microfoam layer at the surface of dried hydrogels based on N,N-dimethylaminoethyl methacrylate. The observations are rationalized on the basis of currently accepted mechanisms for laser-induced polymer surface modification, with a significant contribution of the laser foaming mechanism. Prospective applications of the laser-foamed hydrogel matrices in biomolecule immobilization are suggested.

  16. Radiosensitivity study and radiation effects on morphology characterization of grey oyster mushroom Pleurotus sajor-caju

    Science.gov (United States)

    Rashid, Rosnani Abdul; Daud, Fauzi; Senafi, Sahidan; Awang, Mat Rasol; Mohamad, Azhar; Mutaat, Hassan Hamdani; Maskom, Mohd Meswan

    2014-09-01

    Radiosensitive dosage and morphology characterization of irradiated grey oyster mushroom Pleurotus sajor-caju by gamma rays was investigated due to effects of irradiation. In order to establish the effect, mycelium of P. sajor-caju was irradiated by gamma rays at dose 0.1 to 8.0 kGy with dose rate 0.227 Gy sec-1. The irradiation of mycelia was carried out at the radiation facility in Malaysian Nuclear Agency. The radiosensitivity study was performed by evaluating the percentage of survival irradiated mycelia. The lethal dose of the mycelium P. sajor-caju was determined at 4.0 kGy and LD50 to be equal at 2.2 kGy. The radiation effects on morphology were evaluated based on growth rate of irradiated mycelia, mycelia types, colonization period on substrate, morphology of fruit bodies and yields. The results shown growth rate of irradiated mycelium was slightly lower than the control and decreased as the dose increased. Irradiation was found can induced the primordia formation on PDA and the BE of irradiated seed is higher than to control. The irradiation is proven to be useful for generating new varieties of mushroom with commercial value to the industry.

  17. Nutritional compound analysis and morphological characterization of spider plant (Cleome gynandra) - an African indigenous leafy vegetable.

    Science.gov (United States)

    Omondi, Emmanuel O; Engels, Christof; Nambafu, Godfrey; Schreiner, Monika; Neugart, Susanne; Abukutsa-Onyango, Mary; Winkelmann, Traud

    2017-10-01

    Spider plant is among the important indigenous African leafy vegetables having the potential to contribute to food and nutritional security in sub-Saharan Africa. The main objective of this study was to quantify the mineral concentration, to identify and quantify glucosinolates and flavonoids in spider plant and further to characterize spider plant entries using important morphological traits. Thirty spider plant entries from different African countries, comprising of farmers' cultivars, gene bank accessions and advanced lines were grown in a field experiment and harvested for leaves, stems, flowers and siliques at different developmental stages. Five plant types based on the stem and petiole colorations were identified. Significant genotypic differences were shown for all the morphological traits except for 100 seed weight and silique weight. High mineral concentrations in the leaf tissue were observed especially for potassium, calcium, magnesium, phosphorus, iron, manganese and zinc. The aliphatic 3-hydroxypropyl glucosinolate was the main glucosinolate detected in all tissues with the highest concentrations in the reproductive organs. Glycosides of quercetin, kaempferol and isorhamnetin were the main flavonoids. Isorhamnetin glycosides were detected in trace amounts in both, leaves and inflorescences, while quercetin and kaempferol glycosides were the dominant flavonoids in the leaves and inflorescences, respectively. This knowledge of beneficial nutrient contents is an incentive for promoting spider plant consumption for improved human health while the morphological diversity analysis will be important for the further development of the spider plant germplasm. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Radiosensitivity study and radiation effects on morphology characterization of grey oyster mushroom Pleurotus sajor-caju

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Rosnani Abdul; Awang, Mat Rasol; Mohamad, Azhar; Mutaat, Hassan Hamdani; Maskom, Mohd Meswan [Bioprocess Group, Agrotechnology and Biosciences Division, Malaysian Nuclear Agency, Bangi 43600, Selangor (Malaysia); Daud, Fauzi; Senafi, Sahidan [School of Bioscience and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor (Malaysia)

    2014-09-03

    Radiosensitive dosage and morphology characterization of irradiated grey oyster mushroom Pleurotus sajor-caju by gamma rays was investigated due to effects of irradiation. In order to establish the effect, mycelium of P. sajor-caju was irradiated by gamma rays at dose 0.1 to 8.0 kGy with dose rate 0.227 Gy sec{sup −1}. The irradiation of mycelia was carried out at the radiation facility in Malaysian Nuclear Agency. The radiosensitivity study was performed by evaluating the percentage of survival irradiated mycelia. The lethal dose of the mycelium P. sajor-caju was determined at 4.0 kGy and LD{sub 50} to be equal at 2.2 kGy. The radiation effects on morphology were evaluated based on growth rate of irradiated mycelia, mycelia types, colonization period on substrate, morphology of fruit bodies and yields. The results shown growth rate of irradiated mycelium was slightly lower than the control and decreased as the dose increased. Irradiation was found can induced the primordia formation on PDA and the BE of irradiated seed is higher than to control. The irradiation is proven to be useful for generating new varieties of mushroom with commercial value to the industry.

  19. Morphologic, Phylogenetic and Chemical Characterization of a Brackish Colonial Picocyanobacterium (Coelosphaeriaceae with Bioactive Properties

    Directory of Open Access Journals (Sweden)

    Kerstin Häggqvist

    2016-04-01

    Full Text Available Despite their cosmopolitan distribution, knowledge on cyanobacteria in the family Coelosphaeriaceae is limited. In this study, a single species culture of a coelosphaeran cyanobacterium isolated from a brackish rock pool in the Baltic Sea was established. The strain was characterized by morphological features, partial 16S rRNA sequence and nonribosomal oligopeptide profile. The bioactivity of fractionated extracts against several serine proteases, as well as protein-serine/threonine phosphatases was studied. Phylogenetic analyses of the strain suggested a close relationship with Snowella litoralis, but its morphology resembled Woronichinia compacta. The controversial morphologic and phylogenetic results demonstrated remaining uncertainties regarding species division in this cyanobacteria family. Chemical analyses of the strain indicated production of nonribosomal oligopeptides. In fractionated extracts, masses and ion fragmentation spectra of seven possible anabaenopeptins were identified. Additionally, fragmentation spectra of cyanopeptolin-like peptides were collected in several of the fractions. The nonribosomal oligopeptide profile adds another potential identification criterion in future inter- and intraspecies comparisons of coelosphaeran cyanobacteria. The fractionated extracts showed significant activity against carboxypeptidase A and trypsin. Inhibition of these important metabolic enzymes might have impacts at the ecosystem level in aquatic habitats with high cyanobacteria densities.

  20. Morphological, biochemical, and molecular characterization of Meloidogyne spp. populations from Brazilian soybean production regions

    Directory of Open Access Journals (Sweden)

    Camilla Martins de Oliveira

    Full Text Available ABSTRACT: Soybean is a commodity of great economic importance worldwide, particularly in Brazil, world’s second largest producer. Nematodes, especially those of the Meloidogyne genus, severely limit productivity. Identification of nematode species is important for effective soybean management. Here, 26 populations of root-knot nematode (Meloidogyne spp. from 15 municipalities in the states of Bahia, Mato Grosso, Goias, and Minas Gerais were characterized based on the morphology of the female perineal region, esterase profile, and identification based on amplification of specific regions of the population genome. Among the Meloidogyne spp. populations obtained, M. incognita and M. javanica, were identified. No mixed populations were present in the samples. Diagnosis based on molecular analysis was shown to be reliable and the fastest for characterization of nematode populations compared to other methods analyzed.

  1. Characterization on Contacting Surfaces of MEMS Electrostatic Switches by SEM, EDXA, and XPS

    Directory of Open Access Journals (Sweden)

    I. A. Afinogenov

    2015-01-01

    Full Text Available We focus on the origin and sources of surface contamination and defects causing the failure of MEMS electrostatic switches. The morphology, and elemental and chemical compositions of the contacting surfaces, conducting paths, and other parts of switches have been characterized by means of SEM, EDXA, and XPS in order to understand the difference between the data collected for the devices that had passed the electrical conductivity test and those found to be defective. C, O, Al, Ca, Ti, Cu, and some other impurities were detected on the details of defective switches. Contrariwise, the working switches were found to be clean, at least on the level of EDXA and XPS sensitivity. The main sources of surface contamination and defects were incompletely deleted sacrificial layers, substrate materials, and electrolytes employed for Rh plating of the contacts. The negative influence of foreign microparticles, especially alumina and copper oxides, on the conductivity and porosity of contacts was highlighted.

  2. Characterization and morphological analysis of individual aerosol of PM10 in urban area of Lucknow, India.

    Science.gov (United States)

    Bharti, Sushil Kumar; Kumar, Dhananjay; Anand, Sangeeta; Poonam; Barman, Shymal Chandra; Kumar, Narendra

    2017-12-01

    Airborne particulate matters were collected during the period of October 2015 to September 2016 in Lucknow at different sampling sites. The annual mean concentration of particulate matter was found to be relatively higher than the limits prescribed by National ambient air quality standards (NAAQS), United State Environmental Protection Agency (USEPA) and World Health Organization (WHO). Particulate matters were studied for morphological analysis, elemental composition and functional group variability with the help of Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) followed by Fourier Transform Infrared spectroscopy (FTIR). Morphological characteristics viz. particle count, aspect ratio, circulatory, roundness, equivalent spherical diameter (ESD) and surface area revealed that the particles were perfectly spherical to irregular in shape. Based on the morphology and elemental composition, four clusters of a particulates namely organic particle with inorganic inclusion, soot, tar balls and aluminosilicates were found. FTIR spectra revealed the presence of sulfate, bisulfate, particulate water, silicate, ammonium, aliphatic carbon, aliphatic alcohol, carbonyl and organic nitrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Novel Application of Micro-Computerized Tomography for Morphologic Characterization of the Murine Penis.

    Science.gov (United States)

    O'Neill, Marisol; Huang, Gene O; Lamb, Dolores J

    2017-12-01

    The murine penis model has enriched our understanding of anomalous penile development. The morphologic characterization of the murine penis using conventional serial sectioning methods is labor intensive and prone to errors. To develop a novel application of micro-computerized tomography (micro-CT) with iodine staining for rapid, non-destructive morphologic study of murine penis structure. Penises were dissected from 10 adult wild-type mice and imaged using micro-CT with iodine staining. Images were acquired at 5-μm spatial resolution on a Bruker SkyScan 1272 micro-CT system. After images were acquired, the specimens were washed of any remaining iodine and embedded in paraffin for conventional histologic examination. Histologic and micro-CT measurements for all specimens were made by 2 independent observers. Measurements of penile structures were made on virtual micro-CT sections and histologic slides. The Lin concordance correlation coefficient demonstrated almost perfect strength of agreement for interobserver variability for histologic section (0.9995, 95% CI = 0.9990-0.9997) and micro-CT section (0.9982, 95% CI = 0.9963-0.9991) measurements. Bland-Altman analysis for agreement between the 2 modalities of measurement demonstrated mean differences of -0.029, 0.022, and -0.068 mm for male urogenital mating protuberance, baculum, and penile glans length, respectively. There did not appear to be a bias for overestimation or underestimation of measured lengths and limits of agreement were narrow. The enhanced ability offered by micro-CT to phenotype the murine penis has the potential to improve translational studies examining the molecular pathways contributing to anomalous penile development. The present study describes the first reported use of micro-CT with iodine staining for imaging the murine penis. Producing repeated histologic sections of identical orientation was limited by inherent imperfections in mounting and tissue sectioning, but this was

  4. Characterization of novel silane coatings on titanium implant surfaces

    NARCIS (Netherlands)

    Matinlinna, Jukka P; Tsoi, James Kit‐Hon; de Vries, Jacob; Busscher, Hendrik

    Objectives This in vitro study describes and characterizes a developed novel method to produce coatings on Ti. Hydrophobic coatings on substrates are needed in prosthetic dentistry to promote durable adhesion between luting resin cements and coated Ti surfaces. In implant dentistry the hydrophobic

  5. Formation and surface characterization of nanostructured Al2O3 ...

    Indian Academy of Sciences (India)

    Administrator

    1411. Formation and surface characterization of nanostructured Al2O3–TiO2 coatings. VAIRAMUTHU RAJ* and MOHAMED SIRAJUDEEN MUMJITHA. Advanced Materials ... of the coatings (thickness, growth rate, coating ratio) showed a linear regime with current density and electro- ..... Electronic Supplementary Material.

  6. Simultaneous Morphological and Molecular Characterization of Tatera indica in Southwestern Iran

    Directory of Open Access Journals (Sweden)

    Somayeh Mohammadi

    2015-10-01

    Full Text Available Background: Interest in Tatera indica rodent arises mostly because it is believed that this species is survived among four subspecies reported from Iran, two of which exist in Khuzestan Province. In addition, it might has a role as res­ervoir hosts of zoonotic cutaneous leishmaniasis in the transmission of Leishmania major in some of the widespread Asian foci including southwestern Iran.Methods: Diagnostic morphological and molecular markers for T. indica were sought by characterizing from indi­vidual specimens, such as some taxonomic features and mitochondrial cytochrome b gene that had previously proven useful for the taxonomy of rodents. Wild rodents were caught using live wooden and wire traps. The specimens were identified morphologically using external criteria and molecularly by sequencing of Cyt b gene and phylogenetic analyses. Results: Forty one T. indica were collected and identified morphologically in Khuzestan Province, Iran. Two morphotypes of T. indica were found and classified but sequencing and phylogenetic analyses of mitochondrial Cyt b gene did not support any subspecies between two morphotypes of T. indica.  Because all 21 sequences of both morphotypes of T. indica had no variation with only one common and novel haplotype (GenBank accession No KP001566.Conclusion: This is the first time that T. indica was characterized molecularly in Iran. There is no molecular evi­dence for T. indica morphotypes or subspecies, and so a population genetics approach using several polymorphic genes might be employed using species-specific molecular markers. In addition, more specimens of T. indica species in large geographical locations should be tested. 

  7. Surface modification and characterization of magnesium hydroxide sulfate hydrate nanowhiskers

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-01

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

  8. Fabrication and characterization of multi-level hierarchical surfaces.

    Science.gov (United States)

    Bhushan, Bharat; Lee, Hyungoo

    2012-01-01

    A nanostructured surface may exhibit low adhesion or high adhesion depending upon fibrillar density, and it presents the possibility of realizing eco-friendly surface structures with desirable adhesion by mimicking the mechanics of fibrillar adhesive surfaces of biological systems. The current research uses a patterning technique to fabricate smart adhesion surfaces: one-, two- and three-level hierarchical synthetic adhesive structure surfaces with various fibrillar densities and diameters. The contact angles and contact angle hysteresis were measured to characterize the wettability. A conventional and a glass ball attached to an atomic force microscope (AFM) tip were used to obtain the adhesive forces via force-distance curves and to study the buckling behavior of a single fiber on the hierarchical structures.

  9. Comet 67P's morphological dichotomy and surface evolution from the Rosetta/OSIRIS camera

    Science.gov (United States)

    Ramy El-Maarry, M.; Thomas, Nicolas; Gracia-Berná, Antonio; Pajola, Maurizio; Groussin, Olivier; ROSETTA/OSIRIS

    2016-10-01

    The Rosetta mission orbited comet 67P/Churyumov-Gerasimenko from Aug, 2014 to Sep, 2016. During this time, it obtained the most comprehensive image dataset for a comet's nucleus in terms of resolution, as well as spatial and temporal coverage, using the OSIRIS camera. These images have shown the surface of the comet to be very diverse in its texture and geology. In particular, the 2-year duration of the mission permitted imaging of both hemispheres and the possibility to assess the morphology and surface evolution of comet's 67P's northern hemisphere before and after perihelion passage (in Aug, 2015). The northern hemisphere (NH) is morphologically diverse including regions of consolidated, often fractured materials, smooth terrains showing aeolian-like landforms and seasonal variations, dust-covered areas suggestive of an air-fall-like mechanism, and irregular large-scale depressions suggestive of massive outburst activities. On the other hand, the southern hemisphere (SH) shows a clear dichotomy with the North showing regionally rougher terrains with little or no smooth deposits. Similarly, dusty coatings that were observed in the northern hemisphere are generally lacking in addition to the absence of large depressions. Overall, the SH shows significantly less topographical variation in comparison to the NH. The difference in relief between the NH and SH may be explained by the differences in erosional extent between both hemispheres. The SH has a shorter yet more intensive summer (close to perihelion), which could result in levels of erosion in the SH that are up to a factor of 3 higher than that of the NH. Another notable difference between both hemispheres is the absence of smooth deposits and dust coatings in the SH. The absence of similar deposits in the south may suggest that activity in the SH occurs with much higher intensity leading to ejection of dust particles at velocities exceeding comet's escape velocity. During the meeting, we plan to summarize the

  10. Characterization of the damage produced on different materials surfaces

    International Nuclear Information System (INIS)

    Dellavale Clara, Hector Damian

    2004-01-01

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

  11. Characterization of electric discharge machining, subsequent etching and shot-peening as a surface treatment for orthopedic implants

    Science.gov (United States)

    Stráský, Josef; Havlíková, Jana; Bačáková, Lucie; Harcuba, Petr; Mhaede, Mansour; Janeček, Miloš

    2013-09-01

    Presented work aims at multi-method characterization of combined surface treatment of Ti-6Al-4V alloy for biomedical use. Surface treatment consists of consequent use of electric discharge machining (EDM), acid etching and shot peening. Surface layers are analyzed employing scanning electron microscopy and energy dispersive X-ray spectroscopy. Acid etching by strong Kroll's reagent is capable of removing surface layer of transformed material created by EDM. Acid etching also creates partly nanostructured surface and significantly contributes to the enhanced proliferation of the bone cells. The cell growth could be positively affected by the superimposed bone-inspired structure of the surface with the morphological features in macro-, micro- and nano-range. Shot peening significantly improves poor fatigue performance after EDM. Final fatigue performance is comparable to benchmark electropolished material without any adverse surface effect. The proposed three-step surface treatment is a low-cost process capable of producing material that is applicable in orthopedics.

  12. Effect of surface modification of fly ash on the mechanical, thermal, electrical and morphological properties of polyetheretherketone composites

    International Nuclear Information System (INIS)

    Parvaiz, M. Rahail; Mohanty, Smita; Nayak, Sanjay K.; Mahanwar, P.A.

    2011-01-01

    Research highlights: → Preparation of high performance poly (ether ether ketone) (PEEK)/fly ash (FA) composites. → Characterization studies like DMTA, MDSC, FTIR and SEM have been carried out. → Addition of modified FA, decrease T c by 58 deg. C, due to the hindrance in PEEK molecular mobility during the cooling crystallization process. → Modified fly ash filled PEEK composites exhibit higher tensile strength and modulus than the unmodified ones. - Abstract: Poly (ether ether ketone) (PEEK)/fly ash (FA) composites were prepared using melt blending technique. To improve the interfacial interaction of fly ash with the PEEK matrix, fly ash was chemically modified with calcium hydroxide, at different concentration. Various characterization studies like dynamic mechanical thermal analysis (DMTA), modulated differential scanning calorimetry (MDSC) and scanning electron microscopy (SEM) have been carried out to evaluate the storage modulus, tan δ, crystallinity, and morphology in the composites. SEM micrographs showed more uniform dispersion and interaction in the modified composites than unmodified counterpart. Surface modified fly ash improved the interfacial adhesion between fly ash and PEEK which is confirmed also through improved mechanical strength. The dynamic modulus of PEEK composites exhibited over 133% increment at 100-250 deg. C, indicating improvement of elevated temperature mechanical properties. The modified fly ash reinforcements also showed improvement in glass-transition and crystallization temperature.

  13. Modification of the cellulosic component of hemp fibers using sulfonic acid derivatives: Surface and thermal characterization.

    Science.gov (United States)

    George, Michael; Mussone, Paolo G; Bressler, David C

    2015-12-10

    The aim of this study was to characterize the surface, morphological, and thermal properties of hemp fibers treated with two commercially available, inexpensive, and water soluble sulfonic acid derivatives. Specifically, the cellulosic component of the fibers were targeted, because cellulose is not easily removed during chemical treatment. These acids have the potential to selectively transform the surfaces of natural fibers for composite applications. The proposed method proceeds in the absence of conventional organic solvents and high reaction temperatures. Surface chemical composition and signature were measured using gravimetric analysis, X-ray photoelectron spectroscopy (XPS) and Fourier transform infra-red spectroscopy (FTIR). XPS data from the treated hemp fibers were characterized by measuring the reduction in O/C ratio and an increase in abundance of the C-C-O signature. FTIR confirmed the reaction with the emergence of peaks characteristic of disubstituted benzene and amino groups. Grafting of the sulfonic derivatives resulted in lower surface polarity. Thermogravimetric analysis revealed that treated fibers were characterized by lower percent degradation between 200 and 300 °C, and a higher initial degradation temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Physiological, morphological, and immunochemical parameters used for the characterization of clinical and environmental isolates of Acanthamoeba.

    Science.gov (United States)

    Becker-Finco, A; Costa, A O; Silva, S K; Ramada, J S; Furst, C; Stinghen, A E; De Figueiredo, B C; De Moura, J; Alvarenga, L M

    2013-03-01

    The factors that characterize Acanthamoeba strains as harmless or potentially pathogenic have not been elucidated. Analysing the in vitro and in vivo parameters of Acanthamoeba samples, including heat tolerance at temperatures close to that of the human body, cytopathic effects, and their ability to cause infections in animals, has been proposed to identify their pathogenic potential. Another promising criterion for differentiating strains is the analysis of their biochemical and immunochemical properties. In this study, a comparative evaluation between clinical and environmental Acanthamoeba isolates was performed on the basis of physiological, morphological, and immunochemical criteria. Crude antigens were used to characterize the protein profiles by electrophoresis and immunize mice to produce polyclonal and monoclonal antibodies. The antibodies were characterized using ELISA, Western blotting, and immunofluorescence techniques. The results obtained with polyclonal antibodies suggest the presence of specific proteins for each studied isolate and co-reactive immunochemical profiles among conserved components. Ten monoclonal antibody clones were obtained; mAb3 recognized 3 out of 4 samples studied. The results of this study may help standardize criteria for identifying and characterizing Acanthamoeba strains. Taken together, our results support the view that a set of features may help differentiate Acanthamoeba species and isolates.

  15. MORPHOLOGICAL CHARACTERIZATION OF THE AFRICAN CATFISH (Clarias gariepinus BURCHELL, 1822 STRAINS INTRODUCED TO INDONESIA

    Directory of Open Access Journals (Sweden)

    Bambang Iswanto

    2015-12-01

    Full Text Available African catfish (Clarias gariepinus Burchell, 1822 has become a great important species in Indonesian aquaculture. Several strains of the African catfish have been introduced to Indonesia for aquaculture purposes, initiated by Dumbo strain from Taiwan in 1985, followed by Paiton strain from Thailand in 1998, then Egypt strain from Egypt in 2007, Masamo strain from Thailand in 2010 and later Kenya strain from Kenya in 2011. Since its introductions, there were no reports yet on their characterization studies. The present study was conducted to morphologically characterize the strains of African catfish introduced to Indonesia, i.e. Dumbo, Paiton, Egypt, Masamo, and Kenya strains. Morphometric and meristic data obtained were analyzed using Principal Component Analysis. Results of the morphometric characterization in the present study revealed that Dumbo, Paiton, Masamo, and Kenya strains were indistinguishable, while morphometric characteristic of Egypt strain was more or less different from those of the other strains. On the other hand, results of the meristic characterization suggested that meristic characteristics of all strains of the introduced African catfish were not different from each other. Therefore, to keep the genetic purity of those introduced strains, they should be properly maintained in isolated places.

  16. The effect of activation agent on surface morphology, density and porosity of palm shell and coconut shell activated carbon

    Science.gov (United States)

    Leman, A. M.; Zakaria, S.; Salleh, M. N. M.; Sunar, N. M.; Feriyanto, D.; Nazri, A. A.

    2017-09-01

    Activated carbon (AC) has one of the promising alternative technology for filtration and adsorption process. It inexpensive material because the sources is abundant especially in Malaysia. Main purpose of this project is to develop AC by chemical activation process to improve adsorption capacity by improving porosity of AC. AC developed via carbonization using designed burner at temperature of 650°C to 850 °C and activated by Potassium Hydroxide (KOH) in 12 hour and then dried at temperature of 300°C. Characterization and analysis is conducted by Scanning Electron Microscopy (SEM) for surface morphology analysis, Energy Dispersive Spectroscopy (EDS) for composition analysis, density and porosity analysis. Results shows that uneven surface has been observed both of AC and non-AC and also AC shows higher porosity as compared to non-AC materials. Density value of raw material has lower than AC up to 11.67% and 47.54% and porosity of raw material has higher than AC up to 31.45% and 45.69% for palm shell and coconut shell AC. It can be concluded that lower density represent higher porosity of material and higher porosity indicated higher adsorption capacity as well.

  17. The effects of non-solvent on surface morphology and hydrophobicity of dip-coated polypropylene membrane

    Science.gov (United States)

    Faiqotul Himma, Nurul; Kusuma Wardani, Anita; Gede Wenten, I.

    2017-05-01

    Polypropylene (PP) has been widely used for fabrication of hydrophobic microporous membrane due to its good thermal and chemical stability. However, the hydrophobicity of PP is inadequate to prevent membrane wetting which hinders its application in long-term operation of membrane contactor and other hydrophobic membrane processes. Endowing the membrane with superhydrophobicity has become an attractive way to improve wetting resistance. In this work, superhydrophobic PP membrane was prepared by coating with roughened polymer film. A simple technique of two-step dip-coating was used for deposition of the non-solvent solution and polymer solution. The effects of five non-solvent types were investigated, including ethanol, isopropyl alcohol (IPA), acetone, methyl ethyl ketone (MEK), and cyclohexanone. All non-solvents increased the surface roughness, leading to an improvement of membrane hydrophobicity. Superhydrophobic PP membranes with high water contact angle (WCA) of 150.4° and 151.3° have been successfully prepared by using IPA and MEK, respectively. Morphology characterization revealed that both modified membranes had more uniform and larger number of smaller aggregates which might minimize surface area in contact with liquid, resulting in increased contact angle. As the coating was conducted separately, the utilization of non-solvent could be more effective.

  18. Morphological and animal study of titanium dental implant surface induced by blasting and high intensity pulsed Nd-glass laser

    Energy Technology Data Exchange (ETDEWEB)

    Karacs, A.; Joob Fancsaly, A.; Divinyi, T.; Peto, G.; Kovach, G

    2003-03-03

    Machined dental implants of titanium were blasted with Al{sub 2}O{sub 3} powder of 250 {mu}m particle size. The surface was irradiated in vacuum with a Nd-glass pulsed laser at 1-3 J pulse energies. The morphology of these surfaces was investigated by optical and scanning electron microscopy. The low intensity laser treatment resulted in some new irregularities but we can observe the blasted elements and caves from the original blasted surface too. The blasted elements were washed out and a new surface morphology was induced by the high intensity laser treatment. The osseointegration was determined by measuring the removal torque in the rabbit experiments. The results were referred to the as machined surface. The blasting slightly increased the removal torque. The laser irradiation increased the removal torque significantly, more by a factor of 1.5 compared to the reference at high laser intensity. This shows the influence of the surface morphology on the osseointegration. The combination of the blasting with the laser irradiation is considered a method to determine the morphology optimal for the osseointegration because the pulsed laser irradiation caused modifications of the micrometer sized surface elements and decreases possible surface contamination.

  19. Morphological and animal study of titanium dental implant surface induced by blasting and high intensity pulsed Nd-glass laser

    International Nuclear Information System (INIS)

    Karacs, A.; Joob Fancsaly, A.; Divinyi, T.; Peto, G.; Kovach, G.

    2003-01-01

    Machined dental implants of titanium were blasted with Al 2 O 3 powder of 250 μm particle size. The surface was irradiated in vacuum with a Nd-glass pulsed laser at 1-3 J pulse energies. The morphology of these surfaces was investigated by optical and scanning electron microscopy. The low intensity laser treatment resulted in some new irregularities but we can observe the blasted elements and caves from the original blasted surface too. The blasted elements were washed out and a new surface morphology was induced by the high intensity laser treatment. The osseointegration was determined by measuring the removal torque in the rabbit experiments. The results were referred to the as machined surface. The blasting slightly increased the removal torque. The laser irradiation increased the removal torque significantly, more by a factor of 1.5 compared to the reference at high laser intensity. This shows the influence of the surface morphology on the osseointegration. The combination of the blasting with the laser irradiation is considered a method to determine the morphology optimal for the osseointegration because the pulsed laser irradiation caused modifications of the micrometer sized surface elements and decreases possible surface contamination

  20. Fractal and Lacunarity Analyses: Quantitative Characterization of Hierarchical Surface Topographies.

    Science.gov (United States)

    Ling, Edwin J Y; Servio, Phillip; Kietzig, Anne-Marie

    2016-02-01

    Biomimetic hierarchical surface structures that exhibit features having multiple length scales have been used in many technological and engineering applications. Their surface topographies are most commonly analyzed using scanning electron microscopy (SEM), which only allows for qualitative visual assessments. Here we introduce fractal and lacunarity analyses as a method of characterizing the SEM images of hierarchical surface structures in a quantitative manner. Taking femtosecond laser-irradiated metals as an example, our results illustrate that, while the fractal dimension is a poor descriptor of surface complexity, lacunarity analysis can successfully quantify the spatial texture of an SEM image; this, in turn, provides a convenient means of reporting changes in surface topography with respect to changes in processing parameters. Furthermore, lacunarity plots are shown to be sensitive to the different length scales present within a hierarchical structure due to the reversal of lacunarity trends at specific magnifications where new features become resolvable. Finally, we have established a consistent method of detecting pattern sizes in an image from the oscillation of lacunarity plots. Therefore, we promote the adoption of lacunarity analysis as a powerful tool for quantitative characterization of, but not limited to, multi-scale hierarchical surface topographies.

  1. Tailoring the morphology of raspberry-like carbon black/polystyrene composite microspheres for fabricating superhydrophobic surface

    International Nuclear Information System (INIS)

    Bao, Yubin; Li, Qiuying; Xue, Pengfei; Huang, Jianfeng; Wang, Jibin; Guo, Weihong; Wu, Chifei

    2011-01-01

    In our previous report, raspberry-like carbon black/polystyrene (CB/PS) composite microsphere was prepared through heterocoagulation process. Based on the previous study, in the present work, the morphology of raspberry-like CB/PS particle is tailored through adjusting the polarity and the concentration ratio of CB/PS colloidal suspension with the purpose to prepare particulate film for the fabrication of superhydrophobic surface. Scanning electron microscope (SEM) confirms the morphology of raspberry-like particle and the coverage of CB. Rough surfaces fabricated by raspberry-like particles with proper morphology are observed by SEM and clear evidence of superhydrophobic surface is shown. The structure of raspberry-like particle is analyzed by atom force microscope. The proposed relationship between the hydrophobicity and the structure of CB aggregates on the surface of PS microsphere is discussed in details.

  2. Study of structure and surface morphology of two-layer contact Ti/Al metallization

    Directory of Open Access Journals (Sweden)

    Kirill D. Vanyukhin

    2016-06-01

    Full Text Available Ti/Al/Ni/Au metallization widely used in the technology of GaN base devices have a very important imperfection i.e. rough surface. There are different opinions about the causes of this imperfection: balling-up of molten aluminum or the appearance of intermetallic melt phases in the Au–Al system. To check the effect of the former cause, we have studied the formation of rough surface after annealing of Ti/Al metallization which is used as a basis of many metallization systems for GaN. The substrates were made from silicon wafers covered with Si3N4 films (0.15 μm. On these substrates we deposited the Ti(12 nm/Al(135 nm metallization system. After the deposition the substrates were annealed in nitrogen for 30 s at 850 °С. The as-annealed specimens were tested for metallization sheet resistivity, appearance and surface morphology. We have shown that during annealing of the Ti/Al metallization system, mutual diffusion of the metals and their active interaction with the formation of intermetallic phases occur. This makes the metallization system more resistant to subsequent annealing, oxidation and chemical etching. After annealing the surface of the Ti/Al metallization system becomes gently matted. However, large hemispherical convex areas (as in the Ti/Al/Ni/Au metallization system do not form. Thus, the hypothesis on the balling-up of molten aluminum on the surface of the Ti/Al metallization system has not been confirmed.

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

    International Nuclear Information System (INIS)

    Bau, S.

    2008-12-01

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

  4. Self-Healing Thermal Annealing: Surface Morphological Restructuring Control of GaN Nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, Michele; Li, Haoning; Zubialevich, Vitaly Z.; Kusch, Gunnar; Schmidt, Michael; Collins, Timothy; Glynn, Colm; Martin, Robert W.; O’Dwyer, Colm; Morris, Michael D.; Holmes, Justin D.; Parbrook, Peter J.

    2016-12-07

    With advances in nanolithography and dry etching, top-down methods of nanostructuring have become a widely used tool for improving the efficiency of optoelectronics. These nano dimensions can offer various benefits to the device performance in terms of light extraction and efficiency, but often at the expense of emission color quality. Broadening of the target emission peak and unwanted yellow luminescence are characteristic defect-related effects due to the ion beam etching damage, particularly for III–N based materials. In this article we focus on GaN based nanorods, showing that through thermal annealing the surface roughness and deformities of the crystal structure can be “self-healed”. Correlative electron microscopy and atomic force microscopy show the change from spherical nanorods to faceted hexagonal structures, revealing the temperature-dependent surface morphology faceting evolution. The faceted nanorods were shown to be strain- and defect-free by cathodoluminescence hyperspectral imaging, micro-Raman, and transmission electron microscopy (TEM). In-situ TEM thermal annealing experiments allowed for real time observation of dislocation movements and surface restructuring observed in ex-situ annealing TEM sampling. This thermal annealing investigation gives new insight into the redistribution path of GaN material and dislocation movement post growth, allowing for improved understanding and in turn advances in optoelectronic device processing of compound semiconductors.

  5. Segregation and morphology on the surface of ferritic stainless steel (0 0 1)

    International Nuclear Information System (INIS)

    Fujiyoshi, H.; Matsui, T.; Yuhara, J.

    2012-01-01

    The temperature dependence of the segregation and morphology of ferritic steel (0 0 1) surfaces has been examined by a combination of Auger electron spectroscopy, low-energy electron diffraction (LEED), scanning tunneling microscopy (STM), and low-energy electron loss spectroscopy. Upon annealing ferritic steel at 500 °C, the topmost layer was observed to be mainly composed of Fe-Cr alloy. Oxygen segregation was also detected locally in the STM images. LEED showed a (1 × 1) pattern and a weak (√5 × √5)R27° reconstruction corresponding to Fe and Cr 4 O 5 , respectively. Upon annealing at 600 °C, carbon and chromium co-segregated to the surface, forming two different regions composed of CrC and Cr-based steel, while the Cr 4 O 5 domains disappeared. Upon annealing at 700 °C, nitrogen segregated to the surface, and the topmost layer was observed to be mainly composed of CrN domains with local CrC domains.

  6. Fracture Surface Morphology and Impact Strength of Cellulose/PLA Composites.

    Science.gov (United States)

    Gao, Honghong; Qiang, Tao

    2017-06-07

    Polylactide (PLA)-based composite materials reinforced with ball-milled celluloses were manufactured by extrusion blending followed by injection molding. Their surface morphology from impact fracture were imaged with scanning electron microscopy (SEM) and investigated by calculating their fractal dimensions. Then, linear regression was used to explore the relationship between fractal dimension and impact strength of the resultant cellulose/PLA composite materials. The results show that filling the ball-milled celluloses into PLA can improve the impact toughness of PLA by a minimum of 38%. It was demonstrated that the fracture pattern of the cellulose/PLA composite materials is different from that of pristine PLA. For the resultant composite materials, the fractal dimension of the impact fractured surfaces increased with increasing filling content and decreasing particle size of the ball-milled cellulose particles. There were highly positive correlations between fractal dimension of the fractured surfaces and impact strength of the cellulose/PLA composites. However, the linearity between fractal dimension and impact strength were different for the different methods, due to their different R-squared values. The approach presented in this work will help to understand the structure-property relationships of composite materials from a new perspective.

  7. Surface morphology evolution of amorphous Fe-Si layers upon thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Sun, C M; Tsang, H K; Wong, S P; Ke, N [Department of Electronic Engineering, Chinese University of Hong Kong, Shatin, NT, Hong Kong (China); Hark, S K [Department of Physics, Chinese University of Hong Kong, Shatin, NT, Hong Kong (China)], E-mail: cmsun@ee.cuhk.edu.hk

    2008-04-21

    Changes in the surface morphology of ion-beam-synthesized amorphous Fe-Si layers after rapid thermal annealing (RTA) and furnace annealing (FA) were investigated using atomic force microscopy and transmission electron microscopy. Completely amorphous Fe-Si layers were formed by Fe implantation at a dosage of 5 x 10{sup 15} cm{sup -2} using a metal vapour vacuum arc ion source under 80 kV extraction voltage and cryogenic temperature. After RTA at 850 deg. C, {beta}-FeSi{sub 2} precipitates in Si are completely aggregated from this amorphous Fe-Si layer and the surface of the implanted layer remains flat. To date, no obvious photoluminescence (PL) spectrum has been reported from RTA treated {beta}-FeSi{sub 2} precipitates. However, after annealing at 850 deg. C for 40 s, high-quality {beta}-FeSi{sub 2} precipitates in Si are obtained which clearly show 1.5 {mu}m PL at 80 K for the first time. Even though additional long-term FA at 850 deg. C can enhance PL intensity to a limited extent, the longer thermal treatment induces the outdiffusion of {beta}-FeSi{sub 2} precipitates and degrades the surface flatness.

  8. Differential scanning calorimetry and surface morphology studies on coated pellets using aqueous dispersions.

    Science.gov (United States)

    Nisar-ur-Rahman; K H, Yuen; Jia Woei, Wong; Khan, Nurzalina A k

    2005-04-01

    The present study was conducted to examine the physicochemical changes during passage of drug through polymeric membranes and observe the surface morphology features of the coated pellets using scanning electron microscopy (SEM). Drug solution was first sprayed around inert pellets to form drug-layered pellets that were coated with two commercial aqueous dispersions namely, Eudragit NE30 and Kollicoat SR30 using bottom-spray fluidized bed technique. Differential scanning calorimetry (DSC) confirmed that no interactions existed between drug and polymers. Small peak of drug was observed in the DSC thermograms of Eudragit NE30 coated pellets indicating that small amount of drug was still present in the polymeric membrane after dissolution. Views of SEM revealed as the coating levels of two types of aqueous dispersions were increased the surface of the pellets become more uniform and compact. Therefore, the diffusion length for dissolution medium to enter the drug layer and dissolved drug to diffuse out would be increased at higher coating levels. The polymer surface of coated pellets after 12 hours dissolution testing seemed to be shrunk and size of the pellets were also reduced indicating the depletion of reservoir layer.

  9. Gum ghatti based novel electrically conductive biomaterials: A study of conductivity and surface morphology

    Directory of Open Access Journals (Sweden)

    S. Kalia

    2014-04-01

    Full Text Available Gum ghatti-cl-poly(acrylamide-aniline interpenetrating network (IPN was synthesized by a two-step aqueous polymerization method, in which aniline monomer was absorbed into the network of gum ghatti-cl-poly(acrylamide and followed by a polymerization reaction between aniline monomers. Initially, semi-IPN based on acrylamide and gum ghatti was prepared by free-radical copolymerization in aqueous media with optimized process parameters, using N,N'-methylenebis-acrylamide, as cross-linker and ammonium persulfate, as an initiator system. Optimum reaction conditions affording maximum percentage swelling were: solvent [mL] =12, Acrylamide (AAm [mol•L–1] = 1.971, Ammonium peroxydisulfate (APS [mol•L–1] = 0.131•10–1, N,N'-methylene-bis-acrylamide (MBA [mol•L–1] = 0.162•10–1, reaction time [min] = 210, temperature [°C] = 100 and pH = 7.0. The resulting IPN was doped with different protonic acids. The effect of the doping has been investigated on the conductivity and surface morphology of the IPN hydrogel. The maximum conductivity was observed with 1.5N HClO4 concentration. The morphological, structural and electrical properties of the candidate polymers were studied using scanning electron micrscopy (SEM, Fourier transform infrared spectroscopy FTIR and two-probe method, respectively.

  10. Prediction Surface Morphology of Nanostructure Fabricated by Nano-Oxidation Technology.

    Science.gov (United States)

    Huang, Jen-Ching; Chang, Ho; Kuo, Chin-Guo; Li, Jeen-Fong; You, Yong-Chin

    2015-12-04

    Atomic force microscopy (AFM) was used for visualization of a nano-oxidation technique performed on diamond-like carbon (DLC) thin film. Experiments of the nano-oxidation technique of the DLC thin film include those on nano-oxidation points and nano-oxidation lines. The feature sizes of the DLC thin film, including surface morphology, depth, and width, were explored after application of a nano-oxidation technique to the DLC thin film under different process parameters. A databank for process parameters and feature sizes of thin films was then established, and multiple regression analysis (MRA) and a back-propagation neural network (BPN) were used to carry out the algorithm. The algorithmic results are compared with the feature sizes acquired from experiments, thus obtaining a prediction model of the nano-oxidation technique of the DLC thin film. The comparative results show that the prediction accuracy of BPN is superior to that of MRA. When the BPN algorithm is used to predict nano-point machining, the mean absolute percentage errors (MAPE) of depth, left side, and right side are 8.02%, 9.68%, and 7.34%, respectively. When nano-line machining is being predicted, the MAPEs of depth, left side, and right side are 4.96%, 8.09%, and 6.77%, respectively. The obtained data can also be used to predict cross-sectional morphology in the DLC thin film treated with a nano-oxidation process.

  11. Nanoscale protein arrays of rich morphologies via self-assembly on chemically treated diblock copolymer surfaces

    International Nuclear Information System (INIS)

    Song Sheng; Milchak, Marissa; Zhou Hebing; Lee, Thomas; Hanscom, Mark; Hahm, Jong-in

    2013-01-01

    Well-controlled assembly of proteins on supramolecular templates of block copolymers can be extremely useful for high-throughput biodetection. We report the adsorption and assembly characteristics of a model antibody protein to various polystyrene-block-poly(4-vinylpyridine) templates whose distinctive nanoscale structures are obtained through time-regulated exposure to chloroform vapor. The strong adsorption preference of the protein to the polystyrene segment in the diblock copolymer templates leads to an easily predictable, controllable, rich set of nanoscale protein morphologies through self-assembly. We also demonstrate that the chemical identities of various subareas within individual nanostructures can be readily elucidated by investigating the corresponding protein adsorption behavior on each chemically distinct area of the template. In our approach, a rich set of intricate nanoscale morphologies of protein arrays that cannot be easily attained through other means can be generated straightforwardly via self-assembly of proteins on chemically treated diblock copolymer surfaces, without the use of clean-room-based fabrication tools. Our approach provides much-needed flexibility and versatility for the use of block copolymer-based protein arrays in biodetection. The ease of fabrication in producing well-defined and self-assembled templates can contribute to a high degree of versatility and simplicity in acquiring an intricate nanoscale geometry and spatial distribution of proteins in arrays. These advantages can be extremely beneficial both for fundamental research and biomedical detection, especially in the areas of solid-state-based, high-throughput protein sensing. (paper)

  12. Chemical and morphological characterization of sugarcane bagasse submitted to a delignification process for enhanced enzymatic digestibility

    Science.gov (United States)

    2011-01-01

    Background In recent years, biorefining of lignocellulosic biomass to produce multi-products such as ethanol and other biomaterials has become a dynamic research area. Pretreatment technologies that fractionate sugarcane bagasse are essential for the successful use of this feedstock in ethanol production. In this paper, we investigate modifications in the morphology and chemical composition of sugarcane bagasse submitted to a two-step treatment, using diluted acid followed by a delignification process with increasing sodium hydroxide concentrations. Detailed chemical and morphological characterization of the samples after each pretreatment condition, studied by high performance liquid chromatography, solid-state nuclear magnetic resonance, diffuse reflectance Fourier transformed infrared spectroscopy and scanning electron microscopy, is reported, together with sample crystallinity and enzymatic digestibility. Results Chemical composition analysis performed on samples obtained after different pretreatment conditions showed that up to 96% and 85% of hemicellulose and lignin fractions, respectively, were removed by this two-step method when sodium hydroxide concentrations of 1% (m/v) or higher were used. The efficient lignin removal resulted in an enhanced hydrolysis yield reaching values around 100%. Considering the cellulose loss due to the pretreatment (maximum of 30%, depending on the process), the total cellulose conversion increases significantly from 22.0% (value for the untreated bagasse) to 72.4%. The delignification process, with consequent increase in the cellulose to lignin ratio, is also clearly observed by nuclear magnetic resonance and diffuse reflectance Fourier transformed infrared spectroscopy experiments. We also demonstrated that the morphological changes contributing to this remarkable improvement occur as a consequence of lignin removal from the sample. Bagasse unstructuring is favored by the loss of cohesion between neighboring cell walls, as

  13. Morphological and molecular characterization of Paragonimus caliensis Little, 1968 (Trematoda: Paragonimidae) from Medellin and Pichinde, Colombia.

    Science.gov (United States)

    Lenis, Carolina; Galiano, Alicia; Vélez, Imelda; Vélez, Iván Darío; Muskus, Carlos; Marcilla, Antonio

    2018-03-26

    Paragonimiasis is a subacute to chronic inflammatory granulomatous lung disease caused by the genus Paragonimus. In Latin America Paragonimus mexicanus Miyazaki & Ishii, 1968 is the only confirmed species to cause human infections. Paragonimus caliensis Little, 1968 is an uncommon species often regarded as a synonym of P. mexicanus. Recently, the study of two types of Paragonimus metacercariae from Costa Rica has provided new molecular and morphological evidence that P. caliensis is a separate species from P. mexicanus. In the present study, molecular, morphological and phylogenetic tools have been used to characterize two populations of Paragonimus located at west of Medellin, Antioquia and at Pichinde, Valle del Cauca (type locality of P. caliensis), Colombia. Adults and metacercariae obtained from Medellin, and metacercariae from Pichinde were analyzed. For morphological observations we used light microscopy and scanning electron microscopy (SEM). Morphology of metacercariae and adults matched with the holotype of P. caliensis. The number and arrangement of sensory papillae in the acetabulum region differs from the morphotypes reported for P. caliensis in Costa Rica. Two morphotypes in branching patterns of ovary and two morphotypes in branching patterns of testes were identified. The main morphological differences between P. caliensis and P. mexicanus corresponded to the size of gonads and their relative positions in the body, and the occasional presence of a cyst wall in P. caliensis metacercariae. The molecular and phylogenetic analyses (using nuclear ribosomal ITS2 and partial cytochrome c oxidase subunit 1 CO1 sequences) confirmed that P. caliensis from the type locality is the same species from Medellin and Costa Rica. Furthermore, these analyses also suggest genetic as well as geographical separation of P. caliensis populations between Colombia and Costa Rica. Currently, P. mexicanus and P. caliensis are sympatric in the Colombian Pacific bioregion, and

  14. Chemical and morphological characterization of sugarcane bagasse submitted to a delignification process for enhanced enzymatic digestibility

    Directory of Open Access Journals (Sweden)

    Rezende Camila

    2011-11-01

    Full Text Available Abstract Background In recent years, biorefining of lignocellulosic biomass to produce multi-products such as ethanol and other biomaterials has become a dynamic research area. Pretreatment technologies that fractionate sugarcane bagasse are essential for the successful use of this feedstock in ethanol production. In this paper, we investigate modifications in the morphology and chemical composition of sugarcane bagasse submitted to a two-step treatment, using diluted acid followed by a delignification process with increasing sodium hydroxide concentrations. Detailed chemical and morphological characterization of the samples after each pretreatment condition, studied by high performance liquid chromatography, solid-state nuclear magnetic resonance, diffuse reflectance Fourier transformed infrared spectroscopy and scanning electron microscopy, is reported, together with sample crystallinity and enzymatic digestibility. Results Chemical composition analysis performed on samples obtained after different pretreatment conditions showed that up to 96% and 85% of hemicellulose and lignin fractions, respectively, were removed by this two-step method when sodium hydroxide concentrations of 1% (m/v or higher were used. The efficient lignin removal resulted in an enhanced hydrolysis yield reaching values around 100%. Considering the cellulose loss due to the pretreatment (maximum of 30%, depending on the process, the total cellulose conversion increases significantly from 22.0% (value for the untreated bagasse to 72.4%. The delignification process, with consequent increase in the cellulose to lignin ratio, is also clearly observed by nuclear magnetic resonance and diffuse reflectance Fourier transformed infrared spectroscopy experiments. We also demonstrated that the morphological changes contributing to this remarkable improvement occur as a consequence of lignin removal from the sample. Bagasse unstructuring is favored by the loss of cohesion between

  15. Chemical and morphological characterization of sugarcane bagasse submitted to a delignification process for enhanced enzymatic digestibility.

    Science.gov (United States)

    Rezende, Camila Alves; de Lima, Marisa Aparecida; Maziero, Priscila; deAzevedo, Eduardo Ribeiro; Garcia, Wanius; Polikarpov, Igor

    2011-11-28

    In recent years, biorefining of lignocellulosic biomass to produce multi-products such as ethanol and other biomaterials has become a dynamic research area. Pretreatment technologies that fractionate sugarcane bagasse are essential for the successful use of this feedstock in ethanol production. In this paper, we investigate modifications in the morphology and chemical composition of sugarcane bagasse submitted to a two-step treatment, using diluted acid followed by a delignification process with increasing sodium hydroxide concentrations. Detailed chemical and morphological characterization of the samples after each pretreatment condition, studied by high performance liquid chromatography, solid-state nuclear magnetic resonance, diffuse reflectance Fourier transformed infrared spectroscopy and scanning electron microscopy, is reported, together with sample crystallinity and enzymatic digestibility. Chemical composition analysis performed on samples obtained after different pretreatment conditions showed that up to 96% and 85% of hemicellulose and lignin fractions, respectively, were removed by this two-step method when sodium hydroxide concentrations of 1% (m/v) or higher were used. The efficient lignin removal resulted in an enhanced hydrolysis yield reaching values around 100%. Considering the cellulose loss due to the pretreatment (maximum of 30%, depending on the process), the total cellulose conversion increases significantly from 22.0% (value for the untreated bagasse) to 72.4%. The delignification process, with consequent increase in the cellulose to lignin ratio, is also clearly observed by nuclear magnetic resonance and diffuse reflectance Fourier transformed infrared spectroscopy experiments. We also demonstrated that the morphological changes contributing to this remarkable improvement occur as a consequence of lignin removal from the sample. Bagasse unstructuring is favored by the loss of cohesion between neighboring cell walls, as well as by changes in

  16. 3D Human cartilage surface characterization by optical coherence tomography

    Science.gov (United States)

    Brill, Nicolai; Riedel, Jörn; Schmitt, Robert; Tingart, Markus; Truhn, Daniel; Pufe, Thomas; Jahr, Holger; Nebelung, Sven

    2015-10-01

    Early diagnosis and treatment of cartilage degeneration is of high clinical interest. Loss of surface integrity is considered one of the earliest and most reliable signs of degeneration, but cannot currently be evaluated objectively. Optical Coherence Tomography (OCT) is an arthroscopically available light-based non-destructive real-time imaging technology that allows imaging at micrometre resolutions to millimetre depths. As OCT-based surface evaluation standards remain to be defined, the present study investigated the diagnostic potential of 3D surface profile parameters in the comprehensive evaluation of cartilage degeneration. To this end, 45 cartilage samples of different degenerative grades were obtained from total knee replacements (2 males, 10 females; mean age 63.8 years), cut to standard size and imaged using a spectral-domain OCT device (Thorlabs, Germany). 3D OCT datasets of 8  ×  8, 4  ×  4 and 1  ×  1 mm (width  ×  length) were obtained and pre-processed (image adjustments, morphological filtering). Subsequent automated surface identification algorithms were used to obtain the 3D primary profiles, which were then filtered and processed using established algorithms employing ISO standards. The 3D surface profile thus obtained was used to calculate a set of 21 3D surface profile parameters, i.e. height (e.g. Sa), functional (e.g. Sk), hybrid (e.g. Sdq) and segmentation-related parameters (e.g. Spd). Samples underwent reference histological assessment according to the Degenerative Joint Disease classification. Statistical analyses included calculation of Spearman’s rho and assessment of inter-group differences using the Kruskal Wallis test. Overall, the majority of 3D surface profile parameters revealed significant degeneration-dependent differences and correlations with the exception of severe end-stage degeneration and were of distinct diagnostic value in the assessment of surface integrity. None of the 3D

  17. Surface characterization of industrial flexible polyvinyl(chloride) films

    Science.gov (United States)

    Quesne, Bertrand; Reverdy-Bruas, Nadège; Beneventi, Davide; Chaussy, Didier; Belgacem, Mohamed Naceur

    2014-03-01

    Surface properties of industrial coated plasticized PVC flooring films have been investigated, with the aim of establishing possible additives migration, which causes chemical surface modification of the film and consequently its adhesion behavior. The storage period, from the production time to the converting operations (printing, laminating…) can also promote the additives migration. The surface of these films was extracted with acetone and water and the organic fraction was identified by surface tension, FTIR and GC/MS. These techniques established clearly that the extracted molecules are issuing from the plasticizers. Virgin and aged films were characterized by contact angle measurement and the surface chemistry was directly studied by XPS analyses. The first technique showed stable wettability properties of the films during storage. The contact angle of water droplet was found to decrease step wisely indicating that some surfactant-type molecules were extracted during the measurements, as confirmed by surface tension measurements. XPS established that a higher concentration of the chlorine-free additives was localized on the surface, which points out a probable enrichment of the surface by the plasticizers and the other additives. This suggests that migration kinetic of plasticizers is very high during the production, because of the high processing temperature.

  18. Structural Color Model Based on Surface Morphology of MORPHO Butterfly Wing Scale

    Science.gov (United States)

    Huang, Zhongjia; Cai, Congcong; Wang, Gang; Zhang, Hui; Huttula, Marko; Cao, Wei

    2016-05-01

    Color production through structural coloration is created by micrometer and sub-micrometer surface textures which interfere with visible light. The shiny blue of morpho menelaus is a typical example of structural coloring. Modified from morphology of the morpho scale, a structure of regular windows with two side offsets was constructed on glass substrates. Optical properties of the bioinspired structure were studied through numerical simulations of light scattering. Results show that the structure can generate monochromatic light scattering. Wavelength of scattered light is tunable via changing the spacing between window shelves. Compared to original butterfly model, the modified one possesses larger illumination scopes in azimuthal distributions despite being less in polar directions. Present bionic structure is periodically repeated and is easy to fabricate. It is hoped that the computational materials design work can inspire future experimental realizations of such a structure in photonics applications.

  19. Monitoring of temperature profiles and surface morphologies during laser sintering of alumina ceramics

    Directory of Open Access Journals (Sweden)

    Bin Qian

    2014-06-01

    Full Text Available Additive manufacturing of alumina by laser is a delicate process and small changes of processing parameters might cause less controlled and understood consequences. The real-time monitoring of temperature profiles, spectrum profiles and surface morphologies were evaluated in off-axial set-up for controlling the laser sintering of alumina ceramics. The real-time spectrometer and pyrometer were used for rapid monitoring of the thermal stability during the laser sintering process. An active illumination imaging system successfully recorded the high temperature melt pool and surrounding area simultaneously. The captured images also showed how the defects form and progress during the laser sintering process. All of these real-time monitoring methods have shown a great potential for on-line quality control during laser sintering of ceramics.

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

    Science.gov (United States)

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

    2017-12-01

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

  1. Coevolution of bed surface patchiness and channel morphology: 1. Mechanisms of forced patch formation

    Science.gov (United States)

    Nelson, Peter A.; McDonald, Richard R.; Nelson, Jonathan M.; Dietrich, William E.

    2015-01-01

    Riverbeds frequently display a spatial structure where the sediment mixture composing the channel bed has been sorted into discrete patches of similar grain size. Even though patches are a fundamental feature in gravel bed rivers, we have little understanding of how patches form, evolve, and interact. Here we present a two-dimensional morphodynamic model that is used to examine in greater detail the mechanisms responsible for the development of forced bed surface patches and the coevolution of bed morphology and bed surface patchiness. The model computes the depth-averaged channel hydrodynamics, mixed-grain-size sediment transport, and bed evolution by coupling the river morphodynamic model Flow and Sediment Transport with Morphological Evolution of Channels (FaSTMECH) with a transport relation for gravel mixtures and the mixed-grain-size Exner equation using the active layer assumption. To test the model, we use it to simulate a flume experiment in which the bed developed a sequence of alternate bars and temporally and spatially persistent forced patches with a general pattern of coarse bar tops and fine pools. Cross-stream sediment flux causes sediment to be exported off of bars and imported into pools at a rate that balances downstream gradients in the streamwise sediment transport rate, allowing quasi-steady bar-pool topography to persist. The relative importance of lateral gravitational forces on the cross-stream component of sediment transport is a primary control on the amplitude of the bars. Because boundary shear stress declines as flow shoals over the bars, the lateral sediment transport is increasingly size selective and leads to the development of coarse bar tops and fine pools.

  2. A comparative study on surface morphological investigations of ferric oxide for LPG and opto-electronic humidity sensors

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Satyendra; Verma, Nidhi [Nanomaterials and Sensors Research Laboratory, Department of Physics, University of Lucknow, Lucknow 226007, U.P. (India); Yadav, B.C., E-mail: balchandra_yadav@rediffmail.com [Nanomaterials and Sensors Research Laboratory, Department of Physics, University of Lucknow, Lucknow 226007, U.P. (India); Department of Applied Physics, School for Physical Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, U.P. (India); Prakash, Rajiv [School of Materials Science and Technology, Institute of Technology, Banaras Hindu University, Varanasi 221005 (India)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer Flower-like, elliptical and spherical shaped surface morphologies of Fe{sub 2}O{sub 3}. Black-Right-Pointing-Pointer The structural and surface morphological investigations. Black-Right-Pointing-Pointer The relationship between the surface morphology and sensing property. Black-Right-Pointing-Pointer Advancement in sensitivity of LPG sensor in comparison to prior work. - Abstract: In the present work nanostructured ferric oxides were synthesized via hydroxide precipitation method without using any surfactant and size selection medium. The surface morphologies and structure of samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The structural analysis confirmed the formation of Fe{sub 2}O{sub 3} with {alpha}-phase and rhombohedral structure. Optical and thermal properties were investigated by using UV-visible absorption spectroscopy and differential scanning calorimetry (DSC) techniques. Pelletizations of materials were done using hydraulic press and these pellets were investigated with the exposition of liquefied petroleum gas. Variations in resistance of the pellet with time for different concentrations of LPG were recorded at room temperature (27 Degree-Sign C). The maximum value of average sensitivity was found {approx}5 for 5 vol.% of LPG. Our results show that the LPG sensing behavior was inspired by the different kinds of surface morphologies of Fe{sub 2}O{sub 3} and inferred that the spherical porous nanoparticles synthesized via hydroxide precipitation process (S-3) had best response to LPG.

  3. Surface Characterization of Nanoparticles: Critical Needs and Significant Challenges

    International Nuclear Information System (INIS)

    Baer, Donald R.

    2011-01-01

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

  4. Influence of surface morphology and microstructure on performance of CVD tungsten coating under fusion transient thermal loads

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Youyun, E-mail: lianyy@swip.ac.cn [Southwestern Institute of Physics, Chengdu (China); Liu, Xiang; Wang, Jianbao; Feng, Fan [Southwestern Institute of Physics, Chengdu (China); Lv, Yanwei; Song, Jiupeng [China National R& D Center for Tungsten Technology, Xiamen Tungsten Co. Ltd, 361026 Xiamen (China); Chen, Jiming [Southwestern Institute of Physics, Chengdu (China)

    2016-12-30

    Highlights: • Thick CVD-W coatingswere deposited at a rapid growth rate. • The polished CVD-W coatings have highly textured structure and exhibited a very strong preferred orientation. • The polished CVD tungsten coatings show superior thermal shock resistance as compared with that of the as-deposited coatings. • The crack formation of the polished CVD-W was almost suppressed at an elevated temperature. - Abstract: Thick tungsten coatings have been deposited by chemical vapor deposition (CVD) at a rapid growth rate. A series of tungsten coatings with different thickness and surface morphology were prepared. The surface morphology, microstructure and preferred orientation of the CVD tungsten coatings were investigated. Thermal shock analyses were performed by using an electron beam facility to study the influence of the surface morphology and the microstructure on the thermal shock resistance of the CVD tungsten coatings. Repetitive (100 pulses) ELMs-like thermal shock loads were applied at various temperatures between room temperature and 600 °C with pulse duration of 1 ms and an absorbed power density of up to 1 GW/m{sup 2}. The results of the tests demonstrated that the specific surface morphology and columnar crystal structure of the CVD tungsten have significant influence on the surface cracking threshold and crack propagation of the materials. The CVD tungsten coatings with a polished surface show superior thermal shock resistance as compared with that of the as-deposited coatings with a rough surface.

  5. Genetic characterization of pea (Pisum sativum) germplasm from Turkey using morphological and SSR markers.

    Science.gov (United States)

    Sarikamiş, G; Yanmaz, R; Ermiş, S; Bakir, M; Yüksel, C

    2010-03-30

    The need for the conservation of plant genetic resources has been widely accepted. Germplasm characterization and evaluation yield information for more efficient utilization of these valuable resources. The aim of the present study was to characterize the pea germplasm conserved at the Aegean Agricultural Research Institute of Turkey using morphological and simple sequence repeat (SSR)-based molecular approaches. Genetic characterization of 30 pea genotypes collected from different regions of Turkey and 10 commercial pea cultivars was performed using the criteria of the International Union for the Protection of New Varieties of Plants (UPOV) (TG 7/9 Pisum sativum), and with 10 SSR markers. We originally tested 15 SSR markers; 10 of these markers were selected on the basis of high polymorphism information content in the molecular assays. Sixty-one alleles were detected at the 10 loci. The number of alleles per SSR locus ranged from 3 (PVSBE2) to 12 (AB53), with a mean of 6.1 alleles. The most informative loci were AB53 (12 alleles), AA355 (9 alleles), AD270 (8 alleles), A9 (7 alleles), AD61 (7 alleles), and AB25 (6 alleles). The UPGMA dendrogram defined by SSR markers revealed genetic relatedness of the pea genotypes. These findings can be used to guide future breeding studies and germplasm management of these pea genotypes.

  6. Fast Characterization of Moving Samples with Nano-Textured Surfaces

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  7. Morphological, yield, cytological and molecular characterization of a bread wheat x tritordeum F1 hybrid.

    Science.gov (United States)

    Lima-Brito, J; Carvalho, A; Martin, A; Heslop-Harrison, J S; Guedes-Pinto, H

    2006-08-01

    The morphological, yield, cytological and molecular characteristics of bread wheat x tritordeum F(1) hybrids (2n = 6x = 42; AABBDH(ch)) and their parents were analysed. Morphologically, these hybrids resembled the wheat parent. They were slightly bigger than both parents, had more spikelets per spike, and tillered more profusely. The hybrids are self-fertile but a reduction of average values of yield parameters was observed. For the cytological approach we used a double-target fluorescence in situ hybridization performed with total genomic DNA from Hordeum chilense L. and the ribosomal sequence pTa71. This technique allowed us to confirm the hybrid nature and to analyse chromosome pairing in this material. Our results showed that the expected complete homologous pairing (14 bivalents plus 14 univalents) was only observed in 9.59% of the pollen mother cells (PMCs) analysed. Some PMCs presented autosyndetic pairing of H(ch) and A, B or D chromosomes. The average number of univalents was higher in the wheat genome (6.8) than in the H(ch) genome (5.4). The maximum number of univalents per PMC was 20. We only observed wheat multivalents (one per PMC) but the frequency of trivalents (0.08) was higher than that of quadrivalents (0.058). We amplified 50 RAPD bands polymorphic between the F(1) hybrid and one of its parents, and 31 ISSR polymorphic bands. Both sets of markers proved to be reliable for DNA fingerprinting. The complementary use of morphological and yield analysis, molecular cytogenetic techniques and molecular markers allowed a more accurate evaluation and characterization of the hybrids analysed here.

  8. CT-morphological characterization of respiratory syncytial virus (RSV) pneumonia in immune-compromised adults

    International Nuclear Information System (INIS)

    Mayer, J.L.; Kauczor, H.U.; Lehners, N.; Egerer, G.; Heussel, C.P.

    2014-01-01

    Characterization and follow-up evaluation of chest CT of RSV pneumonia in immune-compromised adults during a seasonal epidemic. Retrospective analysis of 132 chest CT examinations of 51 adult immune-compromised patients (29 m/22f, diameter 58 years) with clinical signs of pneumonia and positive RSV test in winter 2011/2012. Two experienced chest radiologists evaluated the morphology (bronchial wall thickening, tree-in-bud, nodules, halo, ground-glass opacities, consolidations, pleural fluid) of the CT scans by consensus. Pathological findings were in 86 % of the chest CT scans: Areas of ground-glass attenuation in 64 %, consolidations in 56 %, nodules in 55 % (diameter 8 mm in maximal diameter, with halo in 71 %), pleural fluid in 44 % (diameter 2 cm), tree-in-bud in 36 %, bronchial wall thickening in 27 % and more than one morphological finding in 72 %. There were no pathological CT findings in 14 % of patients with clinical symptoms of pneumonia because these patients did not undergo follow-up. Radiological progression was found in 45 % of patients and regression in 33 % in follow-up examinations. In 37 % an additional examination of the paranasal sinuses was performed and showed sinusitis in 63 % of cases. 90 % of the patients had sinusitis as well as pneumonia. In addition to RSV, a further pathogenic agent was found in bronchoalveolar lavage of five patients (Aspergillus spec., herpes simplex virus, Pseudomonas aeruginosa). The most characteristic signs in chest CT scans were at the beginning of pneumonia with nodules and tree-in-bud often combined with bronchial wall thickening. The following CT scans showed characteristic but not pathognomonic chest CT findings of RSV pneumonia. These morphological findings should be recognized seasonally (winter) especially at the beginning of the case of pneumonia. RSV-associated additional sinusitis is probably common and should be noticed.

  9. Fractal analysis as a potential tool for surface morphology of thin films

    Science.gov (United States)

    Soumya, S.; Swapna, M. S.; Raj, Vimal; Mahadevan Pillai, V. P.; Sankararaman, S.

    2017-12-01

    Fractal geometry developed by Mandelbrot has emerged as a potential tool for analyzing complex systems in the diversified fields of science, social science, and technology. Self-similar objects having the same details in different scales are referred to as fractals and are analyzed using the mathematics of non-Euclidean geometry. The present work is an attempt to correlate fractal dimension for surface characterization by Atomic Force Microscopy (AFM). Taking the AFM images of zinc sulphide (ZnS) thin films prepared by pulsed laser deposition (PLD) technique, under different annealing temperatures, the effect of annealing temperature and surface roughness on fractal dimension is studied. The annealing temperature and surface roughness show a strong correlation with fractal dimension. From the regression equation set, the surface roughness at a given annealing temperature can be calculated from the fractal dimension. The AFM images are processed using Photoshop and fractal dimension is calculated by box-counting method. The fractal dimension decreases from 1.986 to 1.633 while the surface roughness increases from 1.110 to 3.427, for a change of annealing temperature 30 ° C to 600 ° C. The images are also analyzed by power spectrum method to find the fractal dimension. The study reveals that the box-counting method gives better results compared to the power spectrum method.

  10. Modified surface morphology of a novel Ti-24Nb-4Zr-7.9Sn titanium alloy via anodic oxidation for enhanced interfacial biocompatibility and osseointegration.

    Science.gov (United States)

    Li, Xiang; Chen, Tao; Hu, Jing; Li, Shujun; Zou, Qin; Li, Yunfeng; Jiang, Nan; Li, Hui; Li, Jihua

    2016-08-01

    The Ti-24Nb-4Zr-7.9Sn titanium alloy (Ti2448) has shown potential for use in biomedical implants, because this alloy possesses several important mechanical properties, such as a high fracture strength, low elastic modulus, and good corrosion resistance. In this study, we aimed to produce a hierarchical nanostructure on the surface of Ti2448 to endow this alloy with favorable biological properties. The chemical composition of Ti2448 (64.0wt% Ti, 23.9wt% Nb, 3.9wt% Zr, and 8.1wt% Sn) gives this material electrochemical properties that lead to the generation of topographical features under standard anodic oxidation. We characterized the surface properties of pure Ti (Ti), nanotube-Ti (NT), Ti2448, and nanotube-Ti2448 (NTi2448) based on surface morphology (scanning electron microscopy and atomic force microscopy), chemical and phase compositions (X-ray diffraction and X-ray photoelectron spectroscopy), and wettability (water contact angle). We evaluated the biocompatibility and osteointegration of implant surfaces by observing the behavior of bone marrow stromal cells (BMSCs) cultured on the surfaces in vitro and conducting histological analysis after in vivo implantation of the modified materials. Our results showed that a hierarchical structure with a nanoscale bone-like layer was achieved along with nanotube formation on the Ti2448 surface. The surface characterization data suggested the superior biocompatibility of the NTi2448 surface in comparison with the Ti, NT, and Ti2448 surfaces. Moreover, the NTi2448 surface showed better biocompatibility for BMSCs in vitro and better osteointegration in vivo. Based on these results, we conclude that anodic oxidation facilitated the formation of a nanoscale bone-like structure and nanotubes on Ti2448. Unlike the modified titanium surfaces developed to date, the NTi2448 surface, which presents both mechanical compatibility and bioactivity, offers excellent biocompatibility and osteointegration, suggesting its potential for

  11. Fabrication and characterization of fully depleted surface barrier detectors

    International Nuclear Information System (INIS)

    Ray, A.

    2010-01-01

    Fabrication of fully depleted surface barrier type thin detectors needs thin silicon wafer of 20 - 30 μm thickness and flatness of ± 1 μm. Process has been developed for thinning silicon wafers to achieve thickness up to 20 - 30 μm from thicker (0.5 - 0.8 mm) silicon samples. These samples were used to fabricate fully depleted surface barrier detectors using Au contacts on n-type silicon. The detectors were characterized by measuring forward and reverse I-V characteristics and alpha energy spectra of Am-Pu source. (author)

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

    Science.gov (United States)

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

    2017-10-01

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

  13. Morphological investigation and physical characterization of ancient fragments of pyrogenic carbon

    International Nuclear Information System (INIS)

    Pusceddu, E; Miglietta, F; Criscuoli, I

    2013-01-01

    In the latest years, the attention toward the use of pyrogenic carbon as a climate mitigation strategy has increasingly grown. Biochar (BC) contains substantial amount (60–90%) of pyrogenic carbon, which is a recalcitrant material and it is hardly decomposed by biotic and abiotic oxidation. The carbon mitigation potential of biochar is associated to the fact that carbon is not easily released back into the atmosphere, even after very long incubation time in the soil. Several studies have been addressing the understanding of the fate of pyrogenic carbon in the soil in a quantitative way, but only a few actually considered materials that were produced in the past and they were not fully able to estimate the fraction of carbon that was oxidized on centennial time scales. In this paper, an old deposits of biochar in soils of the Eastern Alps (Trentino, Val di Pejo) was dated at 1859 by means of a dendroanthracological approach. Carbon decomposition in those soils was then investigated to calculate the fraction of carbon that was lost over 155 years. Part of this study is focused on the morphological and physical characterization of several fragments of biochar, using a scanning electron microscope (SEM). Such study enabled the identification of specific morphological features of tracheids in the old biochar, which were tentatively associated to a differential oxidation of the structures that were created during carbonization from lignin and cellulose

  14. Characterization of Morphological and Cellular Events Underlying Oral Regeneration in the Sea Anemone, Nematostella vectensis.

    Science.gov (United States)

    Amiel, Aldine R; Johnston, Hereroa T; Nedoncelle, Karine; Warner, Jacob F; Ferreira, Solène; Röttinger, Eric

    2015-12-01

    Cnidarians, the extant sister group to bilateria, are well known for their impressive regenerative capacity. The sea anemone Nematostella vectensis is a well-established system for the study of development and evolution that is receiving increased attention for its regenerative capacity. Nematostella is able to regrow missing body parts within five to six days after its bisection, yet studies describing the morphological, cellular, and molecular events underlying this process are sparse and very heterogeneous in their experimental approaches. In this study, we lay down the basic framework to study oral regeneration in Nematostella vectensis. Using various imaging and staining techniques we characterize in detail the morphological, cellular, and global molecular events that define specific landmarks of this process. Furthermore, we describe in vivo assays to evaluate wound healing success and the initiation of pharynx reformation. Using our described landmarks for regeneration and in vivo assays, we analyze the effects of perturbing either transcription or cellular proliferation on the regenerative process. Interestingly, neither one of these experimental perturbations has major effects on wound closure, although they slightly delay or partially block it. We further show that while the inhibition of transcription blocks regeneration in a very early step, inhibiting cellular proliferation only affects later events such as pharynx reformation and tentacle elongation.

  15. Sensory, chemical and morphological characterization of Cucurbita maxima and Cucurbita moschata genotypes from different geographical origins

    Directory of Open Access Journals (Sweden)

    Pevicharova Galina

    2017-01-01

    Full Text Available Cucurbita spp. is one of the most important vegetable crops in the world. They are characterized by great polymorphism according plants and fruits traits. The fruits are consumed in different ways as boiled, baked, dried or processed in puree and juice. The aim of the study was to assess variation of fruit sensory, chemical and morphological characteristics of Cucurbita genotypes in order to find appropriate parental components for the future high quality breeding programme. During 2-year period nine winter squash (Cucurbita maxima Duch. and three pumpkin (Cucurbita moschata Duch. genotypes originating from different geographical regions were tested on their morphological characters, basic chemical components and sensory profile. Cluster analysis and Principle component analysis were applied in order to identify similarities of different genotypes. According to the fruit characteristics and plant habitus significant differences were recorded. Considerable variation in the content of dry matter, ascorbic acid, total sugars, total pigments, beta-carotene and sensory assessment of the boiled fruits was established. Accession Moskatna carotina had the best flavour and chemical composition. The studied Cucurbita genotypes are a good basis for performing a breeding program to improve the sensory quality of fruits and increase basic chemical components especially those with antioxidant effect.

  16. Physiochemical Characterization of Iodine (V Oxide Part II: Morphology and Crystal Structure of Particulate Films

    Directory of Open Access Journals (Sweden)

    Brian K. Little

    2015-11-01

    Full Text Available In this study, the production of particulate films of iodine (V oxides is investigated. The influence that sonication and solvation of suspended particles in various alcohol/ketone/ester solvents have on the physical structure of spin or drop cast films is examined in detail with electron microscopy, powder x-ray diffraction, and UV-visible absorption spectroscopy. Results indicate that sonicating iodine oxides in alcohol mixtures containing trace amounts of water decreases deposited particle sizes and produces a more uniform film morphology. UV-visible spectra of the pre-cast suspensions reveal that for some solvents, the iodine oxide oxidizes the solvent, producing I2 and lowering the pH of the suspension. Characterizing the crystals within the cast films reveal their composition to be primarily HI3O8, their orientations to exhibit a preferential orientation, and their growth to be primarily along the ac-plane of the crystal, enhanced at higher spin rates. Spin-coating at lower spin rates produces laminate-like particulate films versus higher density, one-piece films of stacked particles produced by drop casting. The particle morphology in these films consists of a combination of rods, plates, cubes, and rhombohedra structure.

  17. Morphological-anatomical characterization and molecular identification of Tomentella stuposa ectomycorrhizae and related anatomotypes.

    Science.gov (United States)

    Jakucs, Erzsébet; Kovács, G M; Agerer, R; Romsics, C; Eros-Honti, Z

    2005-06-01

    Species in the genus Tomentella (Thelephoraceae) belong to the most frequent and widespread ectomycorrhizal (EM) fungi found in temperate and boreal forests. Although several unidentified tomentelloid morphotypes have been presented as common members of EM communities in coniferous and broad-leaved forests, few tomentelloid EM have been identified and described in detail. In this study, ten tomentelloid EM isolates collected from Populus alba, Quercus cerris and Picea abies stands in Hungary and Germany are characterized and documented by morphological-anatomical methods using light microscopy. The investigated ectomycorrhizae belong to the same brown-black tomentelloid morphotype but form two different anatomotype groups (At I and At II). Molecular taxonomical identification was accomplished using phylogenetic analysis (neighbor joining method) of 49 Tomentella nrDNA-ITS nucleotide sequences including the 10 new and 39 GenBank sequences. The EM isolates clustered into two adjoining clades identical with the two anatomotypes. At II clustered with Tomentella stuposa while At I could not be identified to species. Based on the morphological similarity and the low genetic difference it must be a closely related taxon. A comparison of the recently known tomentelloid EM to T. stuposa is presented. Ecological questions involving abundance and host relationships are discussed.

  18. Genetic, morphological, and spectral characterization of relictual Niobrara River hybrid aspens (Populus × smithii).

    Science.gov (United States)

    Deacon, Nicholas John; Grossman, Jake Joseph; Schweiger, Anna Katharina; Armour, Isabella; Cavender-Bares, Jeannine

    2017-12-01

    Aspen groves along the Niobrara River in Nebraska have long been a biogeographic curiosity due to morphological differences from nearby remnant Populus tremuloides populations. Pleistocene hybridization between P. tremuloides and P. grandidentata has been proposed, but the nearest P. grandidentata populations are currently several hundred kilometers east. We tested the hybrid-origin hypothesis using genetic data and characterized putative hybrids phenotypically. We compared nuclear microsatellite loci and chloroplast sequences of Niobrara River aspens to their putative parental species. Parental species and putative hybrids were also grown in a common garden for phenotypic comparison. On the common garden plants, we measured leaf morphological traits and leaf-level spectral reflectance profiles, from which chemical traits were derived. The genetic composition of the three unique Niobrara aspen genotypes is consistent with the hybridization hypothesis and with maternal chloroplast inheritance from P. grandidentata . Leaf margin dentition and abaxial pubescence differentiated taxa, with the hybrids showing intermediate values. Spectral profiles allowed statistical separation of taxa in short-wave infrared wavelengths, with hybrids showing intermediate values, indicating that traits associated with internal structure of leaves and water absorption may vary among taxa. However, reflectance values in the visible region did not differentiate taxa, indicating that traits related to pigments are not differentiated. Both genetic and phenotypic results support the hypothesis of a hybrid origin for these genetically unique aspens. However, low genetic diversity and ongoing ecological and climatic threats to the hybrid taxon present a challenge for conservation of these relictual boreal communities. © 2017 Botanical Society of America.

  19. Morphological and molecular characterization of the causal agent of downy mildew on Quinoa (Chenopodium quinoa).

    Science.gov (United States)

    Choi, Young-Joon; Danielsen, Solveig; Lübeck, Mette; Hong, Seung-Beom; Delhey, Rolf; Shin, Hyeon-Dong

    2010-05-01

    Downy mildew is an economically important and widespread disease in quinoa (Chenopodium quinoa) growing areas. Although in many studies Peronospora farinosa is most commonly regarded as the causal agent of the disease, identification and classification of the pathogen remain still uncertain due to its taxonomic confusion. Thirty-six Peronospora isolates from quinoa with different geographic origins including Argentina, Bolivia, Denmark, Ecuador, and Peru were morphologically and molecularly compared with Peronospora species from other Chenopodium species. The morphology of three herbarium specimens was similar to that of P. variabilis, which originated from C. album, characterized by flexuous to curved ultimate branchlets and pedicellated conidia. Phylogenetic analysis based on ITS rDNA sequences also placed the quinoa pathogen within the same clade as P. variabilis. Within the ITS rDNA sequences of the quinoa pathogens, two base substitutions were found, which separated the majority of the Danish isolates from isolates from South America, but no sequence difference was found among the isolates from different cultivars of quinoa. The present results indicate that the pathogen responsible for the quinoa downy mildew is identical to Peronospora variabilis and that it should not be lumped with P. farinosa as claimed previously by most studies.

  20. Characterization of Morphological and Cellular Events Underlying Oral Regeneration in the Sea Anemone, Nematostella vectensis

    Directory of Open Access Journals (Sweden)

    Aldine R. Amiel

    2015-12-01

    Full Text Available Cnidarians, the extant sister group to bilateria, are well known for their impressive regenerative capacity. The sea anemone Nematostella vectensis is a well-established system for the study of development and evolution that is receiving increased attention for its regenerative capacity. Nematostella is able to regrow missing body parts within five to six days after its bisection, yet studies describing the morphological, cellular, and molecular events underlying this process are sparse and very heterogeneous in their experimental approaches. In this study, we lay down the basic framework to study oral regeneration in Nematostella vectensis. Using various imaging and staining techniques we characterize in detail the morphological, cellular, and global molecular events that define specific landmarks of this process. Furthermore, we describe in vivo assays to evaluate wound healing success and the initiation of pharynx reformation. Using our described landmarks for regeneration and in vivo assays, we analyze the effects of perturbing either transcription or cellular proliferation on the regenerative process. Interestingly, neither one of these experimental perturbations has major effects on wound closure, although they slightly delay or partially block it. We further show that while the inhibition of transcription blocks regeneration in a very early step, inhibiting cellular proliferation only affects later events such as pharynx reformation and tentacle elongation.

  1. Nanoparticle synthesis of zinc peroxide: structural and morphological characterization for bactericidal applications

    International Nuclear Information System (INIS)

    Colonia, Roberto; Martinez, Vanessa C.; Solis, Jose L.; Gomez, Monica M.

    2013-01-01

    Zinc peroxide (ZnO 2 ) nanoparticles were synthesized by sol-gel technique. The chemicals used for the synthesis were zinc acetate di-hydrate (Zn(CH 3 COO) 2. 2H 2 O) and hydrogen peroxide (H 2 O 2 ) at 30 % in an aqueous solution with sonication. The structure of the ZnO 2 nanoparticles was characterized by X-ray diffraction. While the morphology and the cluster size were determined using scanning and transmission electron microscopy. For a preliminary evaluation of the bactericidal properties of the ZnO 2 , the material was exposed to Staphylococcus aureus, Escherichia coli y Bacillus subtili, and the nanoparticles presented good bactericidal properties. (author)

  2. A Deep Morphological Characterization and Comparison of Different Dental Restorative Materials

    Directory of Open Access Journals (Sweden)

    R. Condò

    2017-01-01

    Full Text Available Giomer is a relatively new class of restorative material with aesthetics, handling and physical properties of composite resins, and benefits of glass ionomers: high radiopacity, antiplaque effect, fluoride release, and recharge. To verify the superior properties of Giomers, in this study, a deep morphological characterization has been performed with an in vitro comparative study among a Giomer (Beautifil® II by Shofu Dental Corporation, Osaka, Japan, a Compomer (Dyract Extra by Dentsply, Caulk, Germany, glass ionomer cement (Ketac fil plus by 3M ESPE, and a composite resin (Tetric Evoceram by Ivoclar. In particular, mechanical and optical properties and ageing effects have been compared to investigate materials similarities and differences. Indentation tests, UV-Visible spectroscopy, Raman spectroscopy, and weight loss after storage in saliva or sugary drink have been carried out to analyze materials behavior in real conditions. The results confirm the high quality of Giomer material and indicate possible improvements in their usage.

  3. Supramolecular Self-Assembly of a Model Hydrogelator: Characterization of Fiber Formation and Morphology

    Directory of Open Access Journals (Sweden)

    Yuan Gao

    2016-10-01

    Full Text Available Hydrogels are of intense recent interest in connection with biomedical applications ranging from 3-D cell cultures and stem cell differentiation to regenerative medicine, controlled drug delivery, and tissue engineering. This prototypical form of soft matter has many emerging material science applications outside the medical field. The physical processes underlying this type of solidification are incompletely understood, and this limits design efforts aimed at optimizing these materials for applications. We address this general problem by applying multiple techniques (e.g., NMR, dynamic light scattering, small angle neutron scattering, rheological measurements to the case of a peptide derivative hydrogelator (molecule 1, NapFFKYp over a broad range of concentration and temperature to characterize both the formation of individual nanofibers and the fiber network. We believe that a better understanding of the hierarchical self-assembly process and control over the final morphology of this kind of material should have broad significance for biological and medicinal applications utilizing hydrogels.

  4. Asteroid surface materials: mineralogical characterizations from reflectance spectra

    International Nuclear Information System (INIS)

    Gaffey, M.J.; McCord, T.B.

    1978-01-01

    The interpretation of diagnostic parameters in the spectral reflectance data for asteroids provides a means of characterizing the mineralogy and petrology of asteroid surface materials. An interpretive technique based on a quantitative understanding of the functional relationship between the optical properties of a mineral assemblage and its mineralogy, petrology and chemistry can provide a considerably more sophisticated characterization of a single material than any matching or classification technique for those objects bright enough to allow spectral reflectance measurements. Albedos derived from radiometry and polarization data for individual asteroids can be used with spectral data to establish the spectral albedo, to define the optical density of the surface material and, in general to constrain mineralogical interpretations. (Auth.)

  5. Morphological characterization of renal tumours according to decades of life: experience at AFIP Rawalpindi, Pakistan

    International Nuclear Information System (INIS)

    Khadim, M.T.; Rathore, M.U.; Hassan, U.; Ishtiaq, S.; Mushtaq, S.; Nadira, M.

    2010-01-01

    Objective: To evaluate morphological characterization of renal tumours according to decades of life and to compare it with other national and international studies. Study Design: Descriptive study Place and duration of study: The retrospective study was carried out in the Department of Histopathology, Armed Forces Institute of Pathology (AFIP) Rawalpindi during the years 2005 to 2008. Patients and Methods: Data of 236 nephrectomy specimens diagnosed as renal tumours during the years 2005 to 2008 was retrieved from tumour registry of AFIP, Rawalpindi. The morphological characterization of these tumours according to decades of life was done and compared with the international data. Results: Of 236 cases of renal tumours, 169 (72%) were males and 67 (28%) were females. The mean age of the patients was 50 years (SD=18.5) ranging from 1 to 80 years. The most common histological diagnosis in adults was conventional renal cell carcinoma in 172 (73%) patients followed by papillary renal cell carcinoma in 20 (8.5%) patients. Among children Wilm's tumour was the most common in 21 (9%) of patients. Conventional renal cell carcinoma was most commonly diagnosed in the patients aged between 51 to 60 years (52 cases) where as 17 out of 21 cases of Wilm's tumour were diagnosed in the age group of 1 to 10 years. Conclusion: Renal cell tumours are diagnosed in all ages. Conventional renal cell carcinoma and papillary renal cell carcinoma are the most common types in non pediatric age group whereas Wilm's tumor is most common type in pediatric age group. The chromophobe renal cell carcinoma was very rare in our study. Males had a greater incidence as compared to females and incidence of renal tumours has the trend of increase over the years. (author)

  6. Influence of thermal annealing on microstructural, morphological, optical properties and surface electronic structure of copper oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Akgul, Funda Aksoy, E-mail: fundaaksoy01@gmail.com [Department of Physics, Nigde University, 51240 Nigde (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Akgul, Guvenc, E-mail: guvencakgul@gmail.com [Bor Vocational School, Nigde University, 51700 Nigde (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Yildirim, Nurcan [Department of Physics Engineering, Ankara University, 06100 Ankara (Turkey); Department of Metallurgical and Materials Engineering, Middle East Technical University, 06800 Ankara (Turkey); Unalan, Husnu Emrah [Department of Metallurgical and Materials Engineering, Middle East Technical University, 06800 Ankara (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Turan, Rasit [Department of Physics, Middle East Technical University, 06800 Ankara (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey)

    2014-10-15

    In this study, effect of the post-deposition thermal annealing on copper oxide thin films has been systemically investigated. The copper oxide thin films were chemically deposited on glass substrates by spin-coating. Samples were annealed in air at atmospheric pressure and at different temperatures ranging from 200 to 600°C. The microstructural, morphological, optical properties and surface electronic structure of the thin films have been studied by diagnostic techniques such as X-ray diffraction (XRD), Raman spectroscopy, ultraviolet–visible (UV–VIS) absorption spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The thickness of the films was about 520 nm. Crystallinity and grain size was found to improve with annealing temperature. The optical bandgap of the samples was found to be in between 1.93 and 2.08 eV. Cupric oxide (CuO), cuprous oxide (Cu{sub 2}O) and copper hydroxide (Cu(OH){sub 2}) phases were observed on the surface of as-deposited and 600 °C annealed thin films and relative concentrations of these three phases were found to depend on annealing temperature. A complete characterization reported herein allowed us to better understand the surface properties of copper oxide thin films which could then be used as active layers in optoelectronic devices such as solar cells and photodetectors. - Highlights: • Effect of post-deposition annealing on copper oxide thin films was investigated. • Structural, optical, and electronic properties of the thin films were determined. • Oxidation states of copper oxide thin films were confirmed by XPS analysis. • Mixed phases of CuO and Cu{sub 2}O were found to coexist in copper oxide thin films.

  7. Morphological and physicochemical characterization of porous starches obtained from different botanical sources and amylolytic enzymes.

    Science.gov (United States)

    Benavent-Gil, Yaiza; Rosell, Cristina M

    2017-10-01

    Porous starches might offer an attractive alternative as bio-adsorbents of a variety of compounds. However, morphology and physicochemical properties of starches must be understood before exploring their applications. Objective was to study the action of different amylolytic enzymes for producing porous starches. Wheat, rice, potato and cassava starches were treated with Amyloglucosidase (AMG), α-amylase (AM) and cyclodextrin-glycosyltransferase (CGTase). Morphological characteristics, chemical composition, adsorptive capacity and pasting/thermal properties were assessed. Scanning Electron Microscopy (SEM) showed porous structures with diverse pore size distribution, which was dependent on the enzyme type and starch source, but no differences were observed in the total granule surface occupied by pores. The adsorptive capacity analysis revealed that modified starches had high water absorptive capacity and showed different oil adsorptive capacity depending on the enzyme type. Amylose content analysis revealed different hydrolysis pattern of the amylases, suggesting that AMG mainly affected crystalline region meanwhile AM and CGTase attacked amorphous area. A heatmap illustrated the diverse pasting properties of the different porous starches, which also showed significant different thermal properties, with different behavior between cereal and tuber starches. Therefore, it is possible to modulate the properties of starches through the use of different enzymes. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Mesomorphism of Newly Synthesized Mesogens and Surface Morphology of Chalcogenide Glass Thin Films

    Science.gov (United States)

    Sharpnack, Lewis Lee

    -ray reflectivity profiles to facilitate a comparison with other alignment layers that generate liquid crystal alignment primarily because of their anisotropic surface morphology. Our results reveal that As2S3 films develop anisotropic features under irradiation with polarized blue light that are consistent with the changes that occur in other alignment layers when they are "treated" either with mechanical buffing of polymer films or exposure to linearly polarized UV light. These studies also reveal the development of an extensive oxide layer and the ablation of the film under ambient conditions owing to the absorption of oxygen and moisture. This represents a significant barrier to their commercial applications.

  9. Study of surfaces and morphologies of proteic sol–gel derived barium aluminate nanopowders: An experimental and computational study

    International Nuclear Information System (INIS)

    Rezende, M.V. dos S.; Arrouvel, C.; Parker, S.C.; Rey, J.F.Q.; Valerio, M.E.G.

    2012-01-01

    BaAl 2 O 4 nanoparticles samples were prepared by sol–gel proteic route. The preparation of the precursor mixture and the formation of the ceramic product were monitored using TG/DTA, X-ray diffraction (XRD), electron microscopy (SEM, TEM). The results show that sol–gel proteic route is a reliable method for the synthesis of pure BaAl 2 O 4 powders and that irregular hexagonal facetted nanoparticles are observed. Atomistic modeling was used to calculate the structures and energies of 24 (hkl) surfaces and to evaluate morphologies of BaAl 2 O 4 at the thermodynamic and pseudo-kinetic equilibrium. The calculations show that the two most stable surfaces are the (001) and (011) with a surface energy of 1.33 J m −2 and 1.36 J m −2 respectively and that the predicted morphologies are in accord with experiment. -- Highlights: ► Experimental and atomistic simulation techniques to study surfaces and morphologies of pure hexagonal BaAl 2 O 4 phase. ► The irregular hexagonal facetted nanoparticles are observed. ► The kinetic morphology is elongated with a hexagonal termination. ► The most stable surfaces are the (001) and (011) with a surface energy of 1.33 J m −2 .

  10. Surface morphology and chemical composition of TiTa-based surface alloy formed on TiNi by electron beam additive technologies

    Science.gov (United States)

    Gudimova, E. Yu.; Meisner, L. L.; Meisner, S. N.; Yakovlev, E. V.; Shabalina, O. I.

    2017-12-01

    This paper presents research results on the physiochemical and topographic surface properties of a NiTi alloy and their changes after different surface treatments: mechanical polishing, electron beam cleaning, and TiTa-based surface alloying. The possibility of using electron beam treatment for surface preparation with no additional methods is shown. Experiments demonstrate that the TiTa-based alloy surface formed by multiple magnetron deposition of TiTa film and subsequent pulsed electron beam melting of the film/substrate system is chemically and morphologically homogeneous.

  11. Surface Morphology and Growth of Anodic Titania Nanotubes Films: Photoelectrochemical Water Splitting Studies

    Directory of Open Access Journals (Sweden)

    Chin Wei Lai

    2015-01-01

    become the most studied material as they exhibit promising functional properties. In the present study, anodic TiO2 films with different surface morphologies can be synthesized in an organic electrolyte of ethylene glycol (EG by controlling an optimum content of ammonium fluoride (NH4F using electrochemical anodization technique. Based on the results obtained, well-aligned and bundle-free TiO2 nanotube arrays with diameter of 100 nm and length of 8 µm were successfully synthesized in EG electrolyte containing ≈5 wt% of NH4F for 1 h at 60 V. However, formation of nanoporous structure and compact oxide layer would be favored if the content of NH4F was less than 5 wt%. In the photoelectrochemical (PEC water splitting studies, well-aligned TiO2 nanotubular structure exhibited higher photocurrent density of ≈1 mA/cm2 with photoconversion efficiency of ≈2% as compared to the nanoporous and compact oxide layer due to the higher active surface area for the photon absorption to generate more photo-induced electrons during photoexcitation stage.

  12. Seed set, pollen morphology and pollen surface composition response to heat stress in field pea.

    Science.gov (United States)

    Jiang, Yunfei; Lahlali, Rachid; Karunakaran, Chithra; Kumar, Saroj; Davis, Arthur R; Bueckert, Rosalind A

    2015-11-01

    Pea (Pisum sativum L.) is a major legume crop grown in a semi-arid climate in Western Canada, where heat stress affects pollination, seed set and yield. Seed set and pod growth characteristics, along with in vitro percentage pollen germination, pollen tube growth and pollen surface composition, were measured in two pea cultivars (CDC Golden and CDC Sage) subjected to five maximum temperature regimes ranging from 24 to 36 °C. Heat stress reduced percentage pollen germination, pollen tube length, pod length, seed number per pod, and the seed-ovule ratio. Percentage pollen germination of CDC Sage was greater than CDC Golden at 36 °C. No visible morphological differences in pollen grains or the pollen surface were observed between the heat and control-treated pea. However, pollen wall (intine) thickness increased due to heat stress. Mid-infrared attenuated total reflectance (MIR-ATR) spectra revealed that the chemical composition (lipid, proteins and carbohydrates) of each cultivar's pollen grains responded differently to heat stress. The lipid region of the pollen coat and exine of CDC Sage was more stable compared with CDC Golden at 36 °C. Secondary derivatives of ATR spectra indicated the presence of two lipid types, with different amounts present in pollen grains from each cultivar. © 2015 John Wiley & Sons Ltd.

  13. Growth and morphology of sputtered aluminum thin films on P3HT surfaces.

    Science.gov (United States)

    Kaune, Gunar; Metwalli, Ezzeldin; Meier, Robert; Körstgens, Volker; Schlage, Kai; Couet, Sebastien; Röhlsberger, Ralf; Roth, Stephan V; Müller-Buschbaum, Peter

    2011-04-01

    Growth and morphology of an aluminum (Al) contact on a poly(3-hexylthiophene) (P3HT) thin film are investigated with X-ray methods and related to the interactions at the Al:P3HT interface. Grazing incidence small-angle scattering (GISAXS) is applied in situ during Al sputter deposition to monitor the growth of the layer. A growth mode is found, in which the polymer surface is wetted and rapidly covered with a continuous layer. This growth type results in a homogeneous film without voids and is explained by the strong chemical interaction between Al and P3HT, which suppresses the formation of three-dimensional cluster structures. A corresponding three stage growth model (surface bonding, agglomeration, and layer growth) is derived. X-ray reflectivity shows the penetration of Al atoms into the P3HT film during deposition and the presence of a 2 nm thick intermixing layer at the Al:P3HT interface. © 2011 American Chemical Society

  14. Adsorption of Xyloglucan onto Cellulose Surfaces of Different Morphologies: An Entropy-Driven Process.

    Science.gov (United States)

    Benselfelt, Tobias; Cranston, Emily D; Ondaral, Sedat; Johansson, Erik; Brumer, Harry; Rutland, Mark W; Wågberg, Lars

    2016-09-12

    The temperature-dependence of xyloglucan (XG) adsorption onto smooth cellulose model films regenerated from N-methylmorpholine N-oxide (NMMO) was investigated using surface plasmon resonance spectroscopy, and it was found that the adsorbed amount increased with increasing temperature. This implies that the adsorption of XG to NMMO-regenerated cellulose is endothermic and supports the hypothesis that the adsorption of XG onto cellulose is an entropy-driven process. We suggest that XG adsorption is mainly driven by the release of water molecules from the highly hydrated cellulose surfaces and from the XG molecules, rather than through hydrogen bonding and van der Waals forces as previously suggested. To test this hypothesis, the adsorption of XG onto cellulose was studied using cellulose films with different morphologies prepared from cellulose nanocrystals (CNC), semicrystalline NMMO-regenerated cellulose, and amorphous cellulose regenerated from lithium chloride/dimethylacetamide. The total amount of high molecular weight xyloglucan (XGHMW) adsorbed was studied by quartz crystal microbalance and reflectometry measurements, and it was found that the adsorption was greatest on the amorphous cellulose followed by the CNC and NMMO-regenerated cellulose films. There was a significant correlation between the cellulose dry film thickness and the adsorbed XG amount, indicating that XG penetrated into the films. There was also a correlation between the swelling of the films and the adsorbed amounts and conformation of XG, which further strengthened the conclusion that the water content and the subsequent release of the water upon adsorption are important components of the adsorption process.

  15. Evaluation of the morphological alteration of the root surface radiated with a diode laser

    International Nuclear Information System (INIS)

    Gulin, Mauricio

    2003-01-01

    The diode laser has been studied for periodontal therapy, as much for removal of calculus as for microbial reduction of periodontal pockets, as well as the visible analgesic effects and biomodulation capacity. For this reason the purpose of this study was to evaluate the morphological alteration of the root surface after radiation with the diode laser, 808 nm through analysis by scanning electron microscopy (SEM). Besides this, to verify the temperature variations caused during the radiation, a thermometer put into the dentinal wall of the root canal was used. In all, 18 teeth were used, 15 of which for the SEM study, and the other 3 were used to temperature variation analysis. The 25 samples were scraped on the root surface and planed with manual instruments. The other 5 were not subjected to any type of treatment. This, 6 groups of 5 samples each were formed. Control Group C whose samples had not received any treatment; Control Group C 1 was only scraped and polished conventionally with Hu-Friedy Gracey curettes 5 and 6; the other samples groups L1, L2, L3, L4 were radiated by diode laser using parameters of power 1,0 W; 1,2 W; 1,4 W; and 1,6 W respectively, 2 times for 10 seconds with 20 seconds intervals between each radiation in continuous mode. The results with relation to the increase of temperature in the interior of the root canal demonstrated that there was an increase of more than 5 degree Celsius. The results of the scanning electron microscope analysis of Control Group C demonstrated great irregularity and ridges on the root surface, with the presence of a dentine layer. Control Group C1 presented a similar aspect to Group L 1's, smoother and more homogeneous surface. Groups L2, L3, and L4 presented scratches alternating with smoother areas showing that fiber contacted the surface of the sample. The results reconfirmed the necessity of further studies using diode laser, with a beam of light emitted in an interrupted mode to improve the control of the

  16. Surface composition of silver nanocubes and their influence on morphological stabilization and catalytic performance in ethylene epoxidation

    KAUST Repository

    Sangaru, Shiv

    2015-12-04

    Silver nanocubes with exposed (100) facets are reported to have improved selectivity with respect to their spherical counterparts for ethylene epoxidation. In the present study, we observe that the surface composition of the silver nanocubes have also a critical impact on activity. Detailed investigation of the surface composition of silver nanocubes has been carried out using HRTEM, SEM, EDS, EELS and EFTEM. Surfaces of silver nanocubes are “passivated” by chloride and its removal is essential to achieve any catalytic activity. However, the surface chloride is apparently essential for stabilizing the cubic morphology of the particles. Attempts were made to understand the competing effects of the surface species for retaining the morphology of the nanocubes and on their catalytic activity.

  17. Surface characterization of nickel titanium orthodontic arch wires

    Science.gov (United States)

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

    2015-01-01

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

  18. Data on the surface morphology of additively manufactured Ti-6Al-4V implants during processing by plasma electrolytic oxidation

    Directory of Open Access Journals (Sweden)

    Ingmar A.J. van Hengel

    2017-08-01

    Full Text Available Additively manufactured Ti-6Al-4V implants were biofunctionalized using plasma electrolytic oxidation. At various time points during this process scanning electron microscopy imaging was performed to analyze the surface morphology (van Hengel et al., 2017 [1]. This data shows the changes in surface morphology during plasma electrolytic oxidation. Data presented in this article are related to the research article “Selective laser melting porous metallic implants with immobilized silver nanoparticles kill and prevent biofilm formation by methicillin-resistant Staphylococcus aureus” (van Hengel et al., 2017 [1].

  19. Surface morphology of silicone soft relining material after mechanical and chemical cleaning.

    Science.gov (United States)

    Ueda, Takayuki; Kubo, Keitaro; Saito, Takeshi; Obata, Tomokuni; Wada, Takeshi; Yanagisawa, Koichiro; Sakurai, Kaoru

    2018-04-07

    The objective was to investigate the influence of chemical and mechanical cleaning on the surface morphology of a silicone soft relining material. Three plate-shaped specimens were prepared for each group (Control, Hard and Soft) by laminating a 1.5-mm-thick silicone soft relining material. The Control group specimens were stored in water, and the Hard and Soft group specimens were cleaned with hard and soft bristle denture brushes, respectively. Abrasion testing with a toothbrush and immersion testing with an enzyme-containing peroxide denture cleanser were performed, simulating a period of approximately 4 months. The arithmetic mean roughness (Sa) and maximum height of the cross-section (Sz) were measured before and after abrasion and immersion testing. Sa was 4.9±0.9, 22.1±4.2 and 44.2±4.0μm in the Control, Soft and Hard groups, respectively. Sz was 257.5±31.7, 392.0±23.8 and 452.2±41.9μm in the Control, Soft and Hard groups, respectively. After abrasion testing, Sa and Sz differed significantly between the Soft and Control groups and between the Hard and Control groups. Sa was 2.2±1.2μm before and after immersion, and Sz was 142.1±81.4μm before and after immersion. No significant difference was noted in either Sa or Sz in the Control specimens before or after immersion. Surfaces cleaned using a soft bristle brush were less likely to roughen than those cleaned with a hard bristle brush under the conditions of this study. Additionally, chemical cleaning using the enzyme+neutral peroxide denture cleanser did not roughen the surface of the silicone soft relining material. Copyright © 2018 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  20. Surface reactivity, cytotoxic, and morphological transforming effects of diatomaceous Earth products in Syrian hamster embryo cells.

    Science.gov (United States)

    Elias, Zoé; Poirot, Odile; Fenoglio, Ivana; Ghiazza, Mara; Danière, Marie-Céleste; Terzetti, Francine; Darne, Christian; Coulais, Catherine; Matekovits, Ildiko; Fubini, Bice

    2006-06-01

    In order to evaluate the effect of thermal treatments on the surface reactivity and carcinogenic potential of diatomaceous earth (DE) products, the physicochemical features of some specimens--derived by heating the same original material--were compared with their cytotoxic and transforming potency. The samples were an untreated DE (amorphous) progressively heated in the laboratory at 900 degrees C (DE 900) and 1200 degrees C (DE 1200) and a commercial product manufactured from the same DE (Chd) from which the finer fraction ( Chd > DE 900 > DE, suggesting that on heating, the surface acquires a higher potential for free radical release. Most of the silica samples generated COO* radicals from the formate ion, following homolytic rupture of the carbon-hydrogen bond, in the presence of ascorbic acid. A concentration-dependent decrease in cell proliferation and colony-forming efficiency was observed in SHE cultures treated with Chd-F, Chd, and DE. Heating abolished DE cytotoxicity but conferred a transforming ability to thermal treated particles. DE was the only sample that did not induce morphological transformation of cells. According to their transformation capacity, the samples were classified as follows: Chd-F > Chd, DE 1200 > DE 900 > DE. Taken together, the reported results suggest that (1) the transforming potential of a biogenic amorphous silica is related to the thermal treatment that transforms the original structure in cristobalite and generates surface active sites; (2) the reactivity of samples in releasing *OH radicals correlates to their transforming ability; (3) the finer fraction of the commercial product is significantly more toxic and transforming than the coarse dust; and (4) opposite to silica dusts of mineral origin, which loose both cytotoxicity and transforming ability upon heating, heated diatomite acquires a cell-transforming potency. DE products should be thus considered a set apart of silica-based potentially toxic materials.

  1. Characterization of EGF coupling to aminated silicone rubber surfaces.

    Science.gov (United States)

    Klenkler, Bettina J; Sheardown, Heather

    2006-12-20

    Tethering of growth factors to biomaterial substrates via a polyethylene glycol (PEG) spacer has been established as a means of controlling dosage and conformation of the protein at the material surface, while retaining biological activity. However, the extent of modification through a comparison of bound versus unbound protein has not generally been characterized. In this work, covalent tethering of epidermal growth factor (EGF) to allylamine plasma modified polydimethylsiloxane (PDMS) substrates is characterized to determine the nature of the bound growth factor and to optimize the conditions for the reaction. Tethering is achieved via conjugation of EGF with homobifunctional N-hydroxysuccinimide (NHS) ester of PEG-butanoic acid (SBA2-PEG) in solution, followed by exposure of the pegylated EGF to the aminated surfaces (solution first reaction). SDS-PAGE analysis indicates that a low ratio of EGF:PEG is required to maximize the yield of the EGF-PEG reaction; a relatively short reaction time is needed to limit hydrolysis of the NHS ester. With increasing amounts of PEG and a higher reaction time, a higher fraction of the EGF can be covalently tethered to the surfaces, as shown by binding of 125I-labeled EGF and subsequent washing with sodium dodecyl sulfate (SDS) to remove adsorbed protein. However, even under the optimal reaction conditions established by the SDS-PAGE analysis, higher molecular weight EGF-PEG complexes are observed by SDS-PAGE and matrix-assisted laser desorption/ionization (MALDI). The presence of these complexes, as well as unreacted growth factor, can lead to a surface of heterogeneous composition. While these surfaces were found to have biological activity, stimulating the adhesion and growth of corneal epithelial cells versus PDMS controls, further optimization of reaction conditions, including the use of a homobifunctional PEG linker and possibly separation of reaction species are required to achieve a uniformly active and well

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

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  3. Surface morphology modelling for the resistivity analysis of low temperature sputtered indium tin oxide thin films on polymer substrates

    International Nuclear Information System (INIS)

    Yin Xuesong; Tang Wu; Weng Xiaolong; Deng Longjiang

    2009-01-01

    Amorphous or weakly crystalline indium tin oxide (ITO) thin film samples have been prepared on polymethylmethacrylate and polyethylene terephthalate substrates by RF-magnetron sputtering at a low substrate temperature. The surface morphological and electrical properties of the ITO layers were measured by atomic force microscopy (AFM) and a standard four-point probe measurement. The effect of surface morphology on the resistivity of ITO thin films was studied, which presented some different variations from crystalline films. Then, a simplified film system model, including the substrate, continuous ITO layer and ITO surface grain, was proposed to deal with these correlations. Based on this thin film model and the AFM images, a quadratic potential was introduced to simulate the characteristics of the ITO surface morphology, and the classical Kronig-Penney model, the semiconductor electrical theory and the modified Neugebauer-Webb model were used to expound the detailed experimental results. The modelling equation was highly in accord with the experimental variations of the resistivity on the characteristics of the surface morphology.

  4. Effects of polymer surface energy on morphology and properties of silver nanowire fabricated via nanoimprint and E-beam evaporation

    Science.gov (United States)

    Zhao, Zhi-Jun; Hwang, Soon Hyoung; Jeon, Sohee; Jung, Joo-Yun; Lee, Jihye; Choi, Dae-Geun; Choi, Jun-Hyuk; Park, Sang-Hu; Jeong, Jun-Ho

    2017-10-01

    In this paper, we demonstrate that use of different nanoimprint resins as a polymer pattern has a significant effect on the morphology of silver (Ag) nanowires deposited via an E-beam evaporator. RM-311 and Ormo-stamp resins are chosen as a polymer pattern to form a line with dimensions of width (100 nm) × space (100 nm) × height (120 nm) by using nanoimprint lithography (NIL). Their contact angles are then measured to evaluate their surface energies. In order to compare the properties of the Ag nanowires deposited on the various polymer patterns with different surface energies, hydrophobic surface treatment of the polymer pattern surface is implemented using self-assembled monolayers. In addition, gold and aluminum nanowires are fabricated for comparison with the Ag nanowires, with the differences in the nanowire morphologies being determined by the different atomic properties. The monocrystalline and polycrystalline structures of the various Ag nanowire formations are observed using transmission electron microscopy. In addition, the melting temperatures and optical properties of four kinds of Ag nanowire morphologies deposited on various polymer patterns are evaluated using a hot plate and an ultraviolet-visible (UV-vis) spectrometer, respectively. The results indicate that the morphology of the Ag nanowire determines the melting temperature and the transmission. We believe that these findings will greatly aid the development of NIL, along with physical evaporation and chemical deposition techniques, and will be widely employed in optics, biology, and surface wettability applications.

  5. In-Vitro Comparative Study of In-office and Home Bleaching Agents on Surface Micro-morphology of Enamel.

    Science.gov (United States)

    Fatima, Nazish

    2016-01-01

    To evaluate the effect of home-use bleaching agent containing 16% Carbamide Peroxide (CP) and in-office bleaching agent with 38% Hydrogen Peroxide (HP) on surface micro-morphology of enamel. An experimental study. The discs were prepared at Material Engineering Department of NED University of Engineering and Technology, Karachi, and surface morphology was analyzed at Centralized Science Laboratory of Karachi University, Pakistan. Duration of study was one year from January to December 2012. Forty five sound human third molar crowns, extracted for periodontal reason, were included in the study. Longitudinal sections were made using diamond disks (0.2 mm) under water lubrication to obtain enamel slabs measuring (3 mm x 3 mm). The slabs were embedded in polystyrene resin by using 2.0 cm diameter PVC molds, leaving the outer enamel surface uncovered by the resin. Ninety dental enamel slabs were prepared. The slabs were then randomly divided into 3 groups. Each group contained thirty specimens (n=30). Group 1 was kept in artificial saliva at 37°C in incubator (Memart, Germany) during whole experiment. Group 2 was treated with power whitening gel (White Smile 2011, Germany). Group 3 was treated with tooth whitening pen (White Smile 2011, Germany). The most central region or the region that was most representative of the entire surface area was used. The SEM (Jeol-Japan-JSM6380A, JAPAN) micrographs were examined to determine the type of surface presented. The enamel changes were classified as no or mild alteration, moderate alteration and severe altered surface. Regarding micro-morphology, the enamel surface of control groups showed smooth surface in general with some scattered clear scratches due to the polishing procedure. The specimens bleached in group 2 and group 3, represented areas of mild erosion. Bleaching with 38% Hydrogen Peroxide (HP) and 16% Carbamide Peroxide (CP) resulted in mild changes in surface micro-morphology of enamel.

  6. Characterization of carbonaceous combustion residues. I. Morphological, elemental and spectroscopic features.

    Science.gov (United States)

    Fernandes, Milena B; Skjemstad, Jan O; Johnson, Bruce B; Wells, John D; Brooks, Peter

    2003-06-01

    Scanning electron microscopy, surface area determination, elemental analysis, organic matter extraction and solid-state cross polarization/magic angle spinning and Bloch decay/magic angle spinning 13C nuclear magnetic resonance (NMR) spectroscopy were used to investigate distinctive features among carbonaceous combustion residues. Black carbon (BC) samples included diesel soot, urban dust, carbon black, chimney soot, vegetation fire residues, wood and straw charcoals. Particles varied from small spheres (100 m(2)/g), to large layered structures in plant-derived BC (generally 1 micrometer) liquid-like structures, while spherules >100 nm were unique to urban dust. The ratios of amorphous to soot carbon (SC) (isolated by thermal degradation) were not necessarily correlated with the degree of aromaticity estimated from H/C ratios. In particular, values of SC in diesel soot were clearly overestimated. Solvent-extractable organic matter (SEOM) was 13% for urban dust, chimney and diesel soot. SEOM is thought to clog pores or to form large waxy globules, hence reducing surface areas. The ratio of polar/nonpolar SEOM was generally 30 for plant-derived BC. NMR analysis revealed essentially one chemical shift in the aromatic C region of charcoals, while diesel soot also showed important aliphatic contributions. Aliphatic and oxygenated C predominated over aryl C in urban dust and chimney soot. These morphological and chemical characteristics of the BC samples are discussed in terms of their environmental implications.

  7. Carbon steel corrosion induced by sulphate-reducing bacteria in artificial seawater: electrochemical and morphological characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Mariana Silva de; Goncalves, Marcia Monteiro Machado; Rola, Monick Alves da Cruz; Maciel, Diana Jose; Senna, Lilian Ferreira de; Lago, Dalva Cristina Baptista do, E-mail: sdp.mari@gmail.com, E-mail: marciamg@uerj.br, E-mail: monickcruz@yahoo.com.br, E-mail: dijmaciel@gmail.com, E-mail: lsenna@uerj.br, E-mail: dalva@uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Instituto de Quimica

    2016-10-15

    In this work, the corrosion behavior of carbon steel AISI 1020 was evaluated in artificial seawater in the presence of mixed sulfate-reducing bacteria (SRB) culture isolated from the rust of a pipeline. The corrosion evaluation was performed by electrochemical techniques (open circuit potential (E{sub ocp}), polarization curves and electrochemical impedance spectroscopy (EIS)), while the formation of a biofilm and corrosion products were observed by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). The presence of SRB in the medium shifted the open circuit potential to more positive values and increased the corrosion rate of the steel. Electrochemical and morphological techniques confirmed the presence of a biofilm on the steel surface. EDS spectra data showed the presence of sulfur in the corrosion products. After removing the biofilm, localized corrosion was observed on the surface, confirming that localized corrosion had occurred. The biogenic sulfide may lead to the formation of galvanic cells and contributes to cathodic depolarization. (author)

  8. Mineralogical and particulate morphological characterization of geophagic clayey soils from Botswana

    Directory of Open Access Journals (Sweden)

    Georges-Ivo Ekosse

    2012-12-01

    Full Text Available This study focused on determining the minerals composition and particle morphology of geophagic clayey soils from Botswana in order to infer on how they could influence human health. Six representative geophagic clayey soils from Botswana were mineralogically characterized using X-ray powder diffractometry (XRPD, optical microscopy, and environmental scanning electron microscopy (ESEM. Results of identified mineral phases revealed quartz (SiO2 as the most dominant in all samples constituting close to 70 wt %; followed by goethite (FeO.OH having a mean concentration of 9 wt%, and kaolinite (Al2Si2O5(OH4 with a mean concentration of 8 wt%. Other minerals present were smectite ((Na,Ca(Al,Mg6(Si4O103(OH6-n(H2O, mica (AB2-3(Al,SiSi3O10(F,OH2, feldspar (Na/K(AlSi3O8 and hematite (Fe2O3. The quartz particles were generally coarse; and angular to very angular in morphology. Due to ions present in goethite, kaolinite, and smectite, these minerals impact positively on properties of geophagic clayey soils and could possibly influence human health when consumed. The quartz particles could negatively affect dental enamel as a result of mastication; and cause abrasion of the walls of the gastro-intestinal tract which may lead to rupturing. Although the studied clayey soils could have potential to provide medicinal benefits to the consumer, there is need for beneficiation exercise to be conducted to reduce the coarse angular particles contained in them. It is therefore necessary for constructive efforts to be directed at beneficiating geophagic materials which will render them safe for human consumption.DOI: http://dx.doi.org/10.4314/bcse.v26i3.6

  9. Morphological and agronomical characterization and estimates of genetic parameters of sesbania Scop. (Leguminosae accessions

    Directory of Open Access Journals (Sweden)

    Veasey E.A.

    1999-01-01

    Full Text Available Twenty-two accessions of seven Sesbania (Leguminosae species: S. emerus, S. rostrata, S. tetraptera, S. exasperata (annuals, S. grandiflora, S. sesban and S. virgata (perennials, used for ruminant fodder, firewood, wood products, soil improvement, and human food, were investigated, with the aim of characterizing both inter- and intraspecific genetic variability, estimating genetic parameters for the characters evaluated and appraising the forage potential of the accessions. These were planted at the Instituto de Zootecnia, Nova Odessa, SP, Brazil, in a randomized complete block design with 22 treatments and four replications. Seventeen morphological and 17 agronomic characters were evaluated. Genetic parameters coefficient of intraspecific genetic diversity (bi and coefficient of intraspecific genetic variation (CVgi were obtained for the species represented by more than one accession. Highly significant differences were observed among as well as within species for most characters, showing considerable genetic variability. S. exasperata showed intraspecific genetic variability for the largest number of morphological characters. The same was observed for S. sesban for the agronomic characters. Most of the characters gave high bi values, above 0.80, indicating the possibility of selecting superior genotypes. The CVgi values, on the other hand, which indicate the magnitude of the existing genetic variability relative to the character mean, varied according to the species and character evaluated. Differences between annual and perennial species were observed, with higher biomass yields presented by the annuals at the first cut and by the perennials after the second cut, reaching the highest yield at the third cut. The annual species had higher seed production. Accession NO 934 of S. sesban gave the highest biomass yields and regrowth vigor, showing promise as a forage legume plant.

  10. Renal ischemia/reperfusion-induced cardiac hypertrophy in mice: Cardiac morphological and morphometric characterization

    Science.gov (United States)

    Cirino-Silva, Rogério; Kmit, Fernanda V; Trentin-Sonoda, Mayra; Nakama, Karina K; Panico, Karine; Alvim, Juliana M; Dreyer, Thiago R; Martinho-Silva, Herculano

    2017-01-01

    Background Tissue remodeling is usually dependent on the deposition of extracellular matrix that may result in tissue stiffness and impaired myocardium contraction. Objectives We had previously demonstrated that renal ischemia/reperfusion (I/R) is able to induce development of cardiac hypertrophy in mice. Therefore, we aimed to characterize renal I/R-induced cardiac hypertrophy. Design C57BL/6 J mice were subjected to 60 minutes’ unilateral renal pedicle occlusion, followed by reperfusion (I/R) for 5, 8, 12 or 15 days. Gene expression, protein abundance and morphometric analyses were performed in all time points. Results Left ventricle wall thickening was increased after eight days of reperfusion (p < 0.05). An increase in the number of heart ventricle capillaries and diameter after 12 days of reperfusion (p < 0.05) was observed; an increase in the density of capillaries starting at 5 days of reperfusion (p < 0.05) was also observed. Analyses of MMP2 protein levels showed an increase at 15 days compared to sham (p < 0.05). Moreover, TGF-β gene expression was downregulated at 12 days as well TIMP 1 and 2 (p < 0.05). The Fourier-transform infrared spectroscopy analysis showed that collagen content was altered only in the internal section of the heart (p < 0.05); such data were supported by collagen mRNA levels. Conclusions Renal I/R leads to impactful changes in heart morphology, accompanied by an increase in microvasculature. Although it is clear that I/R is able to induce cardiac remodeling, such morphological changes is present in only a section of the heart tissue. PMID:28228941

  11. Renal ischemia/reperfusion-induced cardiac hypertrophy in mice: Cardiac morphological and morphometric characterization

    Directory of Open Access Journals (Sweden)

    Rogério Cirino-Silva

    2017-01-01

    Full Text Available Background Tissue remodeling is usually dependent on the deposition of extracellular matrix that may result in tissue stiffness and impaired myocardium contraction. Objectives We had previously demonstrated that renal ischemia/reperfusion (I/R is able to induce development of cardiac hypertrophy in mice. Therefore, we aimed to characterize renal I/R-induced cardiac hypertrophy. Design C57BL/6 J mice were subjected to 60 minutes’ unilateral renal pedicle occlusion, followed by reperfusion (I/R for 5, 8, 12 or 15 days. Gene expression, protein abundance and morphometric analyses were performed in all time points. Results Left ventricle wall thickening was increased after eight days of reperfusion (p < 0.05. An increase in the number of heart ventricle capillaries and diameter after 12 days of reperfusion (p < 0.05 was observed; an increase in the density of capillaries starting at 5 days of reperfusion (p < 0.05 was also observed. Analyses of MMP2 protein levels showed an increase at 15 days compared to sham (p < 0.05. Moreover, TGF-β gene expression was downregulated at 12 days as well TIMP 1 and 2 (p < 0.05. The Fourier-transform infrared spectroscopy analysis showed that collagen content was altered only in the internal section of the heart (p < 0.05; such data were supported by collagen mRNA levels. Conclusions Renal I/R leads to impactful changes in heart morphology, accompanied by an increase in microvasculature. Although it is clear that I/R is able to induce cardiac remodeling, such morphological changes is present in only a section of the heart tissue.

  12. Phylogenetic, Morphological, and Pathogenic Characterization of Alternaria Species Associated with Fruit Rot of Blueberry in California.

    Science.gov (United States)

    Zhu, X Q; Xiao, C L

    2015-12-01

    Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruit. The aims of this study were to characterize Alternaria isolates using morphological and molecular approaches and test their pathogenicity to blueberry fruit. Alternaria spp. isolates were collected from decayed blueberry fruit in the Central Valley of California during 2012 and 2013. In total, 283 isolates were obtained and five species of Alternaria, including Alternaria alternata, A. tenuissima, A. arborescens, A. infectoria, and A. rosae, were identified based on DNA sequences of the plasma membrane ATPase, Alt a1 and Calmodulin gene regions in combination with morphological characters of the culture and sporulation. Of the 283 isolates, 61.5% were identified as A. alternata, 32.9% were A. arborescens, 5.0% were A. tenuissima, and only one isolate of A. infectoria and one isolate of A. rosae were found. These fungi were able to grow at temperatures from 0 to 35°C, and mycelial growth was arrested at 40°C. Optimal radial growth occurred between 20 to 30°C. Pathogenicity tests showed that all five Alternaria spp. were pathogenic on blueberry fruit at 0, 4, and 20°C, with A. alternata, A. arborescens, and A. tenuissima being the most virulent species, followed by A. infectoria and A. rosae. Previously A. tenuissima has been reported to be the primary cause of Alternaria fruit rot of blueberry worldwide. Our results indicated that the species composition of Alternaria responsible for Alternaria fruit rot in blueberry can be dependent on geographical region. A. alternata, A. arborescens, A. infectoria, and A. rosae are reported for the first time on blueberry in California. This is also the first report of A. infectoria and A. rosae infecting blueberry fruit.

  13. Surface morphology of PMMA/boehmite hybrid nanostructures prepared via facile one-pot process

    Science.gov (United States)

    Ghamari, Misagh; Farzi, Gholamali

    2017-08-01

    In this study, we developed the novel aqueous-based PMMA/AlOOH hybrid by a one-pot process starting from their relevant precursors in a controlled manner. Starting chemical reactions directly from precursors and the sequence of adding reactants provide the possibility towards enhancing the homogeneity of the final product. Inorganic and organic segments were made compatible by means of oleic acid as a coupling agent. Boehmite to PMMA weight ratio as the main parameter was varied from 0 to 18% and the morphology, particle size, size distribution, and topography map of hybrids was shown to be composition dependent. Final PMMA/Bo nanohybrids were characterized using FTIR to confirm the chemical interactions between inorganic and organic segments. TEM analysis showed that nanohybrid particles with irregular shapes containing inorganic particles dispersed in the organic matrix are formed with an average diameter which depends on boehmite content. The presence of phase transformation of Bo makes PMMA/Bo hybrids significantly thermally stable. According to AFM topography map analysis and relevant Gaussian fit function, the roughness of nanocomposite, the size of hybrid nanoparticles and deviation from the mean value (size) were increased as Bo increases from 0 to 18.

  14. Characterization of Human Gingival Fibroblasts on Zirconia Surfaces Containing Niobium Oxide

    Directory of Open Access Journals (Sweden)

    Young-Dan Cho

    2015-09-01

    Full Text Available It was indicated that tetragonal zirconia polycrystal (TZP containing yttria (Y2O3 and niobium oxide (Nb2O5 ((Y,Nb-TZP could be an adequate dental material to be used at esthetically important sites. The (Y,Nb-TZP was also proved to possess its osteogenic potential comparable with those conventional dental implant material, titanium (Ti. The objective of the current study was to characterize cellular response of human gingival fibroblasts (HGFs to smooth and rough surfaces of the (Y,Nb-TZP disc, which were obtained by polishing and sandblasting, respectively. Various microscopic, biochemical, and molecular techniques were used to investigate the disc surfaces and cellular responses for the experimental (Y,Nb-TZP and the comparing Ti groups. Sandblasted rough (Y,Nb-TZP (Zir-R discs had the highest surface roughness. HGFs cultured on polished (Y,Nb-TZP (Zir showed a rounded cell morphology and light spreading at 6 h after seeding and its proliferation rate significantly increased during seven days of culture compared to other surfaces. The mRNA expressions of type I collagen, integrin α2 and β1 were significantly stimulated for the Zir group at 24 h after seeding. The current findings, combined with the previous results, indicate that (Y,Nb-TZP provides appropriate surface condition for osseointegration at the fixture level and for peri-implant mucosal sealing at the abutment level producing a suitable candidate for dental implantation with an expected favorable clinical outcome.

  15. Characterization and conditioning of SSPX plasma facing surfaces

    International Nuclear Information System (INIS)

    Buchenauer, D.A.; Mills, B.E.; Wood, R.; Woodruff, S.; Hill, D.N.; Hooper, E.B.; Cowgill, D.F.; Clift, M.W.; Yang, N.Y.

    2001-01-01

    The Sustained Spheromak Physics Experiment (SSPX) will examine the confinement properties of spheromak plasmas sustained by DC helicity injection. Understanding the plasma-surface interactions is an important component of the experimental program since the spheromak plasma is in close contact with a stabilizing wall (flux conserver) and is maintained by a high current discharge in the coaxial injector region. Peak electron temperatures in the range of 400 eV are expected, so the copper plasma facing surfaces in SSPX have been coated with tungsten to minimize sputtering and plasma contamination. Here, we report on the characterization and conditioning of these surfaces used for the initial studies of spheromak formation in SSPX. The high pressure plasma-sprayed tungsten facing the SSPX plasma was characterized in situ using β-backscattering and ex situ using laboratory measurements on similarly prepared samples. Measurements showed that water can be desorbed effectively through baking while the removal rates of volatile impurity gases during glow discharge and shot conditioning indicated a large source of carbon and oxygen in the porous coating

  16. Morphological characterization of Langmuir-Blodgett films from polyaniline and a ruthenium complex (Rupy): influence of the relative concentration of Rupy

    International Nuclear Information System (INIS)

    Souza, Nara C de; Ferreira, Marystela; Wohnrath, Karen; Silva, Josmary R; Oliveira Osvaldo, N Jr; Giacometti, Jose A

    2007-01-01

    We report on the use of dynamic scale theory and fractal analyses in a study of the growth stages of Langmuir-Blodgett (LB) films of polyaniline and a neutral biphosphinic ruthenium complex, namely mer-[RuCl 3 (dppb)(py)] (dppb = 1,4-bis(diphenylphosphine)buthane, py = pyridine), Rupy. The LB films were deposited onto indium-tin-oxide substrates and characterized with atomic force microscopy. From the granular morphology exhibited by the films one could infer growth processes inside and outside the grains. Growth outside was found to follow the Kardar-Parisi-Zhang model, with fractal dimensions of about 2.7. As one would expect, inside the grains the morphology is close to a Euclidian surface with fractal dimension of about 2

  17. Morphological and structural characterization of the Zn0,9Mn0,1O powder synthesized by combustion reaction and Pechini

    International Nuclear Information System (INIS)

    Ribeiro, M.A.; Torquato, R.; Simoes, A.N.; Costa, A.C.F.M.; Gama, L.; Kiminami, R.H.G.A.

    2009-01-01

    Zinc oxide, due to the piezoelectric and electro-optical characteristics, is used in application such as, chemical sensor, varistor, transparent conductive thin film and DMS. The aim of this work is to evaluate and compare structural and morphological characteristics of nanometric powders of Zn 0,9 Mn 0,1 O prepared by chemical synthesis of combustion reaction and Pechini method. The powders were characterized by XRD, SEM and BET. The XRD data shown to both studied method the presence of ZnO phase with hexagonal structure and without second phase. The powder prepared by combustion reaction presented 9% of reduction in crystallinity and 42% of increase in surface area in comparison with the powder prepared by Pechini method. The morphological analysis of the powder showed that both method produce powders with soft agglomerates constituted by nano size particles. (author)

  18. AFM capabilities in characterization of particles and surfaces: from angstroms to microns.

    Science.gov (United States)

    Starostina, N; Brodsky, M; Prikhodko, S; Hoo, C M; Mecartney, M L; West, P

    2008-01-01

    Scanning probe microscopy (SPM), invented 25 years ago, is now routinely employed as a surface characterization technique. Atomic force microscopy (AFM) is the most widely used form of SPM, since AFM can be used in ambient conditions with minimal sample preparation. Examples of applications relevant to cosmetics include, but are not limited to, hair and skin roughness measurements and powder particle and nano-emulsion characterization. AFM is well suited for individual particle characterization, especially for measurements of volume, height, size, shape, aspect ratio, and particle surface morphology. Statistical distributions for a large set of particles can be generated through single-particle analysis techniques (i.e., ensemble-like information). AFM is better capable of resolving complex particle-size distributions than dynamic light-scattering (DLS). Single-particle analysis techniques with AFM can be more cost- and time-effective than analyses using scanning electron microscopy (SEM). However, AFM offers resolution that is comparable to or greater than SEM or transmission electron microscopy (TEM) and routinely allows direct measurements of the particle height and volume and produces images easily displayed in a quantified 3D format.

  19. Surface structural, morphological, and catalytic studies of homogeneously dispersed anisotropic Ag nanostructures within mesoporous silica

    Energy Technology Data Exchange (ETDEWEB)

    Sareen, Shweta [Thapar University, School of Chemistry and Biochemistry (India); Mutreja, Vishal [Maharishi Markandeshwar University, Department of Chemistry (India); Pal, Bonamali; Singh, Satnam, E-mail: ssingh@thapar.edu [Thapar University, School of Chemistry and Biochemistry (India)

    2016-11-15

    Highly dispersed anisotropic Ag nanostructures were synthesized within the channels of 3-aminopropyltrimethoxysilane (APTMS)-modified mesoporous SBA-15 for catalyzing the reduction of p-dinitrobenzene, p-nitrophenol, and p-nitroacetophenone, respectively. A green templating process without involving any reducing agent, by varying the amount (1–10 wt.%) of Ag loading followed by calcination at 350 °C under H{sub 2} led to change in the morphology of Ag nanoparticles from nanospheres (~7–8 nm) to nanorods (aspect ratio ~12–30 nm) without any deformation in mesoporous sieves. In comparison to white bare SBA-15, gray-colored samples were formed with Ag impregnation exhibiting absorption bands at 484 and 840 nm indicating the formation of anisotropic Ag nanostructures within mesoporous matrix. TEM and FE-SEM micrographs confirmed the presence of evenly dispersed Ag nanostructures within as well as on the surface of mesoporous matrix. AFM studies indicated a small decrease in the average roughness of SBA-15 from 20.59 to 19.21 nm for 4 wt.% Ag/m-SBA-15, illustrating the encapsulation of majority of Ag nanoparticles in the siliceous matrix and presence of small amount of Ag nanoparticles on the mesoporous support. Moreover, due to plugging of mesopores with Ag, a significant decrease in surface area from 680 m{sup 2}/g of SBA-15 to 385 m{sup 2}/g was observed. The Ag-impregnated SBA-15 catalyst displayed superior catalytic activity than did bare SBA-15 with 4 wt.% Ag-loaded catalyst exhibiting optimum activity for selective reduction of p-nitrophenol to p-aminophenol (100 %), p-nitroacetophenone to p-aminoacetophenone (100 %), and p-dinitrobenzene to p-nitroaniline (87 %), with a small amount of p-phenylenediamine formation.

  20. Physicochemical Characterization of Capstone Depleted Uranium Aerosols III: Morphologic and Chemical Oxide Analyses

    International Nuclear Information System (INIS)

    Krupka, Kenneth M.; Parkhurst, MaryAnn; Gold, Kenneth; Arey, Bruce W.; Jenson, Evan D.; Guilmette, Raymond A.

    2009-01-01

    The impact of depleted uranium (DU) penetrators against an armored target causes erosion and fragmentation of the penetrators, the extent of which is dependent on the thickness and material composition of the target. Vigorous oxidation of the DU particles and fragments creates an aerosol of DU oxide particles and DU particle agglomerations combined with target materials. Aerosols from the Capstone DU aerosol study, in which vehicles were perforated by DU penetrators, were evaluated for their oxidation states using X-ray diffraction (XRD) and particle morphologies using scanning electron microscopy/energy dispersive spectrometry (SEM/EDS). The oxidation state of a DU aerosol is important as it offers a clue to its solubility in lung fluids. The XRD analysis showed that the aerosols evaluated were a combination primarily of U3O8 (insoluble) and UO3 (relatively more soluble) phases, though intermediate phases resembling U4O9 and other oxides were prominent in some samples. Analysis of particle residues in the micrometer-size range by SEM/EDS provided microstructural information such as phase composition and distribution, fracture morphology, size distribution, and material homogeneity. Observations from SEM analysis show a wide variability in the shapes of the DU particles. Some of the larger particles appear to have been fractured (perhaps as a result of abrasion and comminution); others were spherical, occasionally with dendritic or lobed surface structures. Amorphous conglomerates containing metals other than uranium were also common, especially with the smallest particle sizes. A few samples seemed to contain small chunks of nearly pure uranium metal, which were verified by EDS to have a higher uranium content exceeding that expected for uranium oxides. Results of the XRD and SEM/EDS analyses were used in other studies described in this issue of The Journal of Health Physics to interpret the results of lung solubility studies and in selecting input parameters for

  1. Physicochemical characterization of Capstone depleted uranium aerosols III: morphologic and chemical oxide analyses.

    Science.gov (United States)

    Krupka, Kenneth M; Parkhurst, Mary Ann; Gold, Kenneth; Arey, Bruce W; Jenson, Evan D; Guilmette, Raymond A

    2009-03-01

    The impact of depleted uranium (DU) penetrators against an armored target causes erosion and fragmentation of the penetrators, the extent of which is dependent on the thickness and material composition of the target. Vigorous oxidation of the DU particles and fragments creates an aerosol of DU oxide particles and DU particle agglomerations combined with target materials. Aerosols from the Capstone DU aerosol study, in which vehicles were perforated by DU penetrators, were evaluated for their oxidation states using x-ray diffraction (XRD), and particle morphologies were examined using scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). The oxidation state of a DU aerosol is important as it offers a clue to its solubility in lung fluids. The XRD analysis showed that the aerosols evaluated were a combination primarily of U3O8 (insoluble) and UO3 (relatively more soluble) phases, though intermediate phases resembling U4O9 and other oxides were prominent in some samples. Analysis of particle residues in the micrometer-size range by SEM/EDS provided microstructural information such as phase composition and distribution, fracture morphology, size distribution, and material homogeneity. Observations from SEM analysis show a wide variability in the shapes of the DU particles. Some of the larger particles were spherical, occasionally with dendritic or lobed surface structures. Others appear to have fractures that perhaps resulted from abrasion and comminution, or shear bands that developed from plastic deformation of the DU material. Amorphous conglomerates containing metals other than uranium were also common, especially with the smallest particle sizes. A few samples seemed to contain small bits of nearly pure uranium metal, which were verified by EDS to have a higher uranium content exceeding that expected for uranium oxides. Results of the XRD and SEM/EDS analyses were used in other studies described in this issue of Health Physics to interpret the

  2. Direct observation of bulk and surface chemical morphologies of Ginkgo biloba leaves by Fourier transform mid- and near-infrared microspectroscopic imaging.

    Science.gov (United States)

    Chen, Jianbo; Sun, Suqin; Zhou, Qun

    2013-11-01

    Fourier transform infrared microspectroscopy is a powerful tool to obtain knowledge about the spatial and/or temporal distributions of the chemical compositions of plants for better understanding of their biological properties. However, the chemical morphologies of plant leaves in the plane of the blade are barely studied, because sections in this plane for mid-infrared transmission measurements are difficult to obtain. Besides, native compositions may be changed by chemical reagents used when plant samples are microtomed. To improve methods for direct infrared microspectroscopic imaging of plant leaves in the plane of the blade, the bulk and surface chemical morphologies of nonmicrotomed Ginkgo biloba leaves were characterized by near-infrared transmission and mid-infrared attenuated total reflection microspectroscopic imaging. A new self-modeling curve resolution procedure was proposed to extract the spectral and concentration information of pure compounds. Primary and secondary metabolites of secretory cavities, veins, and mesophylls of Ginkgo biloba leaf blades were analyzed, and the distributions of cuticle, protein, calcium oxalate, cellulose, and ginkgolic acids on the adaxial surface were determined. By the integration of multiple infrared microspectroscopic imaging and chemometrics methods, it is possible to analyze nonmicrotomed leaves and other plant samples directly to understand their native chemical morphologies in detail.

  3. [Acetabular morphological analysis in patients with high dislocated DDH using three-dimensional surface reconstruction technique].

    Science.gov (United States)

    Zengy, Yi; Min, Li; Lai, Ou-jie; Shen, Bin; Yang, Jing; Zhou, Zong-ke; Kang, Peng-de; Pei, Fu-xing

    2015-03-01

    To simulate acetabular morphology and perform acetabular quantitative analysis in high dislocated developmental dysplasia of the hip (DDH) patients using three-dimensional (3D) surface reconstruction technique, in order to understand the acetabular anatomic features and develop operative strategies for acetabular reconstruction. 3D pelvic images were reconstructed by Mimics software from CT data of 13 patients (13 hips) with high developmental DDH and 13 normal persons (26 hips). True acetabular superior-inferior diameter, anterior-posterior diameter, acetabular depth, medial wall thickness, abduction angle and anteversion angle were measured and compared between the two groups of participants. Irregular acetabular shape was found in high dislocated group, showing a triangle with wide upper and narrow lower. The acetabular quantitative analysis revealed (38.29 +/- 2.71) mm superior-inferior diameter, (21.74 +/- 5.33) mm anterior-posterior diameter, (15.50 +/- 2.93) mm acetabular depth, (6.80 +/- 2.97) mm medial wall thickness, (49.29 +/- 7.40) degrees abduction angle and (23.82 +/- 11.21) degrees anteversion angle in high dislocated patients. The superior-inferior diameter, anterior-posterior diameter and acetabular depth of high dislocated patients were significantly smaller than those of the normal contirols (PDDH patients have acetabular features: irregular shape, lower opening, higher medial wall and bigger abduction and anteversion angles. Joint arthroplasty surgery in high dislocated DDH patients needs to look at these acetabular features.

  4. Determination of surface morphology of TiO2 nanostructure using synchrotron radiation

    Science.gov (United States)

    Das, Gangadhar; Kumar, Manoj; Biswas, A. K.; Khooha, Ajay; Mondal, Puspen; Tiwari, M. K.

    2017-05-01

    Nanostructures of Titanium oxide (TiO2) are being studied for many promising applications, e.g., solar photovoltaics, solar water splitting for H2 fuel generation etc., due to their excellent photo-catalytic properties. We have synthesized low-dimensional TiO2 nanoparticles by gas phase CW CO2 laser pyrolysis. The laser synthesis process has been optimized for the deposition of highly pure, nearly mono-dispersed TiO2 nanoparticles on silicon substrates. Hard x-ray standing wave-field (XSW) measurements in total reflection geometry were carried out on the BL-16 beamline of Indus-2 synchrotron radiation facility in combination with x-ray reflectivity and grazing incidence x-ray fluorescence measurements for the determination of surface morphology of the deposited TiO2 nanostructures. The average particle size of TiO2 nanostructure estimated using transmission electron microscopy (TEM) was found to closely agree with the XSW and grazing incidence x-ray diffraction (GIXRD) results.

  5. Development and application of new instrumental techniques for real-time characterization of aerosol volatility and morphology

    Science.gov (United States)

    Huffman, John Alexander

    Aerosols represent the area of largest uncertainty in the radiative forcing of climate and contribute significantly to negative effects on human health and visibility. To better understand the balance between natural and anthropogenic aerosol emissions, and thus the systemic perturbations caused by human activity, advanced instrumentation is needed to measure ambient aerosol properties. This thesis presents the development of novel aerosol measurement instrumentation and resulting observations of aerosol morphology and volatility. A particle beam width probe (BWP) for use within the Aerosol Mass Spectrometer (AMS) and an associated computational model were developed to aid the direct determination of ambient particle morphology and investigate AMS quantification. BWP observations and model results helped determine that particles were not lost in the instrument by morphology-related effects, but were instead collected less efficiently due to particle bounce from the vaporizer surface. This study introduces psi, the lift-shape factor, which allows for the direct determination of particle non-sphericity through use of the BWP. The development and characterization of an instrument modified to directly measure chemically-resolved aerosol volatility is described. A thermodenuder operated between 50-230°C was coupled to a High-Resolution Time-of-Flight AMS (HR-ToF-AMS) with a fast-switching valve system, thus allowing direct and chemically-resolved aerosol volatility measurements to be made for the first time. The instrument was applied in two polluted, urban field studies (Riverside, CA and Mexico City, Mexico) and to sample several biomass-burning, meat-cooking and chamber-generated secondary organic aerosol (SOA) sources. Reduced hydrocarbon-like OA (HOA), biomass-burning OA (BBOA) and oxygenated OA (OOA) were all determined to be semi-volatile, with the most aged OOA-1 consistently showing the lowest volatility. This represents a significant departure from most

  6. Morphological and molecular characterization of the senile osteoporosis in senescence-accelerated mouse prone 6 (SAMP6).

    Science.gov (United States)

    Azuma, Kagaku; Zhou, Qian; Kubo, Kin-Ya

    2018-04-04

    Although the understanding of the complex pathogenesis for osteoporosis is appreciable, the underlying mechanism is not yet fully elucidated. There is a great need to further characterize the available animal models in osteoporosis research. The senescence-accelerated mouse prone 6 (SAMP6) mice have been developed as the spontaneous experimental model for senile osteoporosis. Here, we provide a comprehensive overview of current research regarding the bone morphological and molecular alterations and the possible mechanisms involved in these changes. There were significant decrease in trabecular bone mass at the axial and appendicular skeletal sites, with no marked alterations of cortical bone. Decreased bone formation on the endosteal surface and trabecular bone, and increased bone marrow adiposity were observed in SAMP6 mice. The elevated expression level of proliferator activator gamma (PPARγ) in the bone marrow suggest that PPARγ might regulate osteoblastic bone formation negatively in SAMP6 mice. The expression level of secreted frizzled-related protein 4 (Sfrp4) was found to be higher in SAMP6 mice. Sfrp4 is considered to suppress osteoblastic proliferation mediated by inhibition of Wnt signaling pathway. These findings may help us to gain more insight into the potential mechanism of senile osteoporosis.

  7. Role of nanoclay shape and surface characteristics on the morphology and thermal properties of polystyrene nanocomposites synthesized via emulsion polymerization

    CSIR Research Space (South Africa)

    Greesh, N

    2013-10-01

    Full Text Available This work evaluates the role of the surface properties and shape of clay type on the morphology, thermal, and thermo-mechanical properties of the polystyrene (PS)/clay nanocomposites prepared via free-radical emulsion polymerization. Attapulgite...

  8. Micro-morphology of single crystalline silicon surfaces during anisotropic wet chemical etching in KOH: velocity source forests

    NARCIS (Netherlands)

    van Veenendaal, E.; Sato, K.; Shikida, M.; Shikida, M.; Nijdam, A.J.; van Suchtelen, J.

    2001-01-01

    For silicon etched in KOH the micro-morphology of any surface, no matter the crystallographic orientation, is defined by some sort of persistent corrugations. As a matter of principle, the occurrence of these corrugations is incompatible with the classical kinematic wave theory for the evolution of

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

    Science.gov (United States)

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

    2018-01-01

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

  10. Use of digital image analysis combined with fractal theory to determine particle morphology and surface texture of quartz sands

    Directory of Open Access Journals (Sweden)

    Georgia S. Araujo

    2017-12-01

    Full Text Available The particle morphology and surface texture play a major role in influencing mechanical and hydraulic behaviors of sandy soils. This paper presents the use of digital image analysis combined with fractal theory as a tool to quantify the particle morphology and surface texture of two types of quartz sands widely used in the region of Vitória, Espírito Santo, southeast of Brazil. The two investigated sands are sampled from different locations. The purpose of this paper is to present a simple, straightforward, reliable and reproducible methodology that can identify representative sandy soil texture parameters. The test results of the soil samples of the two sands separated by sieving into six size fractions are presented and discussed. The main advantages of the adopted methodology are its simplicity, reliability of the results, and relatively low cost. The results show that sands from the coastal spit (BS have a greater degree of roundness and a smoother surface texture than river sands (RS. The values obtained in the test are statistically analyzed, and again it is confirmed that the BS sand has a slightly greater degree of sphericity than that of the RS sand. Moreover, the RS sand with rough surface texture has larger specific surface area values than the similar BS sand, which agree with the obtained roughness fractal dimensions. The consistent experimental results demonstrate that image analysis combined with fractal theory is an accurate and efficient method to quantify the differences in particle morphology and surface texture of quartz sands.

  11. Evolution effects of the copper surface morphology on the nucleation density and growth of graphene domains at different growth pressures

    Science.gov (United States)

    Hedayat, Seyed Mahdi; Karimi-Sabet, Javad; Shariaty-Niassar, Mojtaba

    2017-03-01

    In this work, we study the influence of the surface morphology of the catalytic copper substrate on the nucleation density and the growth rate of graphene domains at low and atmospheric pressure chemical vapor deposition (LPCVD and APCVD) processes. In order to obtain a wide range of initial surface morphology, precisely controlled electropolishing methods were developed to manipulate the roughntreess value of the as-received Cu substrate (RMS = 30 nm) to ultra-rough (RMS = 130 nm) and ultra-smooth (RMS = 2 nm) surfaces. The nucleation and growth of graphene domains show obviously different trends at LPCVD and APCVD conditions. In contrast to APCVD condition, the nucleation density of graphene domains is almost equal in substrates with different initial roughness values at LPCVD condition. We show that this is due to the evolution of the surface morphology of the Cu substrate during the graphene growth steps. By stopping the surface sublimation of copper substrate in a confined space saturated with Cu atoms, the evolution of the Cu surface was impeded. This results in the reduction of the nucleation density of graphene domains up to 24 times in the pre-smoothed Cu substrates at LPCVD condition.

  12. Morphology of the occlusal surfaces of premolar and molar teeth as an indicator of age in the horse.

    Science.gov (United States)

    Carmalt, J L; Allen, A L

    2008-09-01

    The purpose of this study was to investigate the use of cheek tooth occlusal surface morphology as an indicator of age in the horse using a blinded cross-sectional design. Twenty horses of varying age, breed and sex were used. Horses of known age (foaling date) were euthanized for reasons other than dental disease. Following disarticulation of the head and sectioning of the mandibles, cheek teeth were cleaned using running water and photographs were taken of each arcade. Using a computer-based program, the total surface area of each premolar and molar, the outer enamel ridge perimeter distance, infundibular surface areas and perimeter distances were measured. Further anatomical data were calculated from these measurements and a statistical analysis of the relationship between horse age and cheek tooth occlusal morphology was performed. Results indicated that multiple anatomical regions within the occlusal surface of the equine cheek tooth can be used as an indicator of age. There are important differences between mandibular and maxillary teeth as well as between teeth in the same dental arcade. Horse size is also of significance. The mesial infundibular surface area as a percentage of the total surface area of tooth 111, and the mesiodistal length of 1/2/3/4 09 teeth, most closely approximates age within our mathematical model. Cheek tooth morphological data can be used to predict age in horses that possess all their permanent dentition. In cases in which the age of horses cannot be accurately determined from incisor examination, cheek teeth may be used.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-15

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

  14. Microanalytical characterization of surface decoration in Majolica pottery

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  15. Comparison of optical methods for surface roughness characterization

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  16. Effects of scaffold surface morphology on cell adhesion and survival rate in vitreous cryopreservation of tenocyte-scaffold constructs

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhi [State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041 (China); Department of Bone and Joint Surgery, The affiliated hospital of Luzhou Medical College, Luzhou 646000 (China); Qing, Quan [Sichuan College of Traditional Chinese Medicine, Mianyang 621000 (China); Regenerative Medicine Research Center, West China Hospital of Sichuan University, Chengdu 610041 (China); Chen, Xi; Liu, Cheng-Jun; Luo, Jing-Cong [State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041 (China); Hu, Jin-Lian [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China); Qin, Ting-Wu, E-mail: tingwuqin@hotmail.com [State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041 (China)

    2016-12-01

    Highlights: • The shapes of tenocytes varied when seeded on different surface of scaffolds. • Tenocytes were flat on smooth surface and spindle on micro-grooved surface. • Tenocytes were ellipse or spindle on porous surface. • Tenocytes got varying adhesion shape and elongation index on varying surfaces. • The tenocyte survival on porous surface was superior to the other two groups. - Abstract: The purpose of this study was to investigate the effects of scaffold surface morphology on cell adhesion and survival rate in vitreous cryopreservation of tenocyte-scaffold constructs. Tenocytes were obtained from tail tendons of rats. Polydimethylsiloxane (PDMS) was used to fabricate three types of scaffolds with varying surface morphological characteristics, i.e., smooth, micro-grooved, and porous surfaces, respectively. The tenocytes were seeded on the surfaces of the scaffolds to form tenocyte-scaffold constructs. The constructs were cryopreserved in a vitreous cryoprotectant (CPA) with a multi-step protocol. The cell adhesion to scaffolds was observed with electronic scanning microscopy (SEM). The elongation index of the living tenocytes and ratio of live/dead cell number were examined based on a live/dead dual fluorescent staining technique, and the survival rate of tenocytes was studied with flow cytometry (FC). The results showed the shapes of tenocytes varied between the different groups: flat or polygonal (on smooth surface), spindle (on micro-grooved surface), and spindle or ellipse (on porous surface). After thawing, the porous surface got the most living tenocytes and a higher survival rate, suggesting its potential application for vitreous cryopreservation of engineered tendon constructs.

  17. Raman and Surface-Enhanced Raman Scattering for Biofilm Characterization

    Directory of Open Access Journals (Sweden)

    Seda Keleştemur

    2018-01-01

    Full Text Available Biofilms are a communal way of living for microorganisms in which microorganism cells are surrounded by extracellular polymeric substances (EPS. Most microorganisms can live in biofilm form. Since microorganisms are everywhere, understanding biofilm structure and composition is crucial for making the world a better place to live, not only for humans but also for other living creatures. Raman spectroscopy is a nondestructive technique and provides fingerprint information about an analyte of interest. Surface-enhanced Raman spectroscopy is a form of this technique and provides enhanced scattering of the analyte that is in close vicinity of a nanostructured noble metal surface such as silver or gold. In this review, the applications of both techniques and their combination with other biofilm analysis techniques for characterization of composition and structure of biofilms are discussed.

  18. Characterization and morphology of solids suspended in rain water; Caracterizacion y morfologia de solidos suspendidos en agua de lluvia

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Mexico D.F. (Mexico)

    2000-07-01

    This work presents the results obtained from the analysis of rain water in Mexico. The study treats over the characterization and morphology of the solids suspended in form of particles in the atmosphere. The solids suspended were obtained of the pluvial precipitations after these have been centrifuged. Subsequently of the separation, the particulate matter was analysed by Sem and X-ray dispersive energy.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mattioli, Michele, E-mail: michele.mattioli@uniurb.it [Department of Earth, Life and Environment Sciences, University of Urbino, 61029 Urbino (Italy); Giordani, Matteo [Department of Earth, Life and Environment Sciences, University of Urbino, 61029 Urbino (Italy); Dogan, Meral [Geological Engineering Department, Hacettepe University, Beytepe, Ankara, Turkey & Center for Global and Regional Environmental Research, University of Iowa, Iowa City, Iowa 52242 (United States); Cangiotti, Michela; Avella, Giuseppe [Department of Earth, Life and Environment Sciences, University of Urbino, 61029 Urbino (Italy); Giorgi, Rodorico [Department of Chemistry, University of Florence, 50019 Firenze (Italy); Dogan, A. Umran [Chemical and Biochemical Engineering Department & Center for Global and Regional Environmental Research, University of Iowa, Iowa City, Iowa 52242 (United States); Ottaviani, Maria Francesca, E-mail: maria.ottaviani@uniurb.it [Department of Earth, Life and Environment Sciences, University of Urbino, 61029 Urbino (Italy)

    2016-04-05

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

  20. Molecular characterization of water and surfactant AOT at nanoemulsion surfaces.

    Science.gov (United States)

    Hensel, Jennifer K; Carpenter, Andrew P; Ciszewski, Regina K; Schabes, Brandon K; Kittredge, Clive T; Moore, Fred G; Richmond, Geraldine L

    2017-12-19

    Nanoemulsions and microemulsions are environments where oil and water can be solubilized in one another to provide a unique platform for many different biological and industrial applications. Nanoemulsions, unlike microemulsions, have seen little work done to characterize molecular interactions at their surfaces. This study provides a detailed investigation of the near-surface molecular structure of regular (oil in water) and reverse (water in oil) nanoemulsions stabilized with the surfactant dioctyl sodium sulfosuccinate (AOT). Vibrational sum-frequency scattering spectroscopy (VSFSS) is used to measure the vibrational spectroscopy of these AOT stabilized regular and reverse nanoemulsions. Complementary studies of AOT adsorbed at the planar oil-water interface are conducted with vibrational sum-frequency spectroscopy (VSFS). Jointly, these give comparative insights into the orientation of interfacial water and the molecular characterization of the hydrophobic and hydrophilic regions of AOT at the different oil-water interfaces. Whereas the polar region of AOT and surrounding interfacial water molecules display nearly identical behavior at both the planar and droplet interface, there is a clear difference in hydrophobic chain ordering even when possible surface concentration differences are taken into account. This chain ordering is found to be invariant as the nanodroplets grow by Ostwald ripening and also with substitution of different counterions (Na:AOT, K:AOT, and